Motorized Travel 

Management 

Supplemental Draft 

Environmental Impact Statement 

Volume 1: Chapters 1 – 4 

United States 

Department of 

Agriculture 

Forest Service

Pacific Southwest 

Region 

Tahoe National Forest 

R5-MB-208a 

February 2010 

Volunteers assisting Forest Service with maintenance of the Rubicon Jeep Trail 
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Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Tahoe National Forest – i

Motorized Travel Management

Supplemental Draft

Environmental Impact Statement

Nevada, Placer, Plumas, Sierra and Yuba Counties, California

February 2010

Volume 1: Chapters 1 – 4

Lead Agency: US Forest Service

Cooperating Agencies: None

Responsible Official: Tom Quinn

Forest Supervisor

Tahoe National Forest

631 Coyote Street

Nevada City, California 95959

For Information, Contact: David Arrasmith

631 Coyote Street

Nevada City, California 95959

(530) 478-6220

Email: darrasmith@fs.fed.us

Abstract: This Supplemental Draft Environmental Impact Statement (SDEIS) describes seven 

alternatives, six of which propose changes to the National Forest Transportation System (NFTS) and 

would prohibit cross country travel on the Tahoe National Forest (TNF). These actions are needed in 

order to implement the 2005 Travel Management Rule (36 CFR Part 212, Subpart B) while providing for 

a diversity of motor vehicle recreation opportunities and providing motorized access to dispersed 

recreation opportunities on the TNF. The SDEIS discloses environmental impacts associated with the 

Proposed Action, a No Action Alternative and 5 additional alternatives developed to meet the purpose and 

need and to respond to issues raised by the public.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Summary

ii – Tahoe National Forest

Summary

Proposed Action as Described in the Notice of Intent _________ 

1. Prohibition of Cross Country Travel: Public wheeled motor vehicle travel off designated 

NFTS roads, NFTS trails, and outside designated motorized use areas would be prohibited, 

except as allowed by permit or other authorization.

2. Additions to the NFTS:

a. No unauthorized routes would be added as roads to the NFTS.

b. 36.7 miles (36 routes) of unauthorized routes would be added as motorized trails to the 

NFTS.

3. Establishment of Motorized “Open Areas”: No additional motorized “Open Areas” would be 

established.

4. Changes to the NFTS: 

a. Change Vehicle Classes through Mixed Use: No changes would be made to allow licensed 

operators of non-highway legal vehicles to operate on NFTS roads where such use is 

currently prohibited through approval of mixed use.

b. Change Vehicle Classes through Maintenance Levels: Change vehicle class on 3.4 miles to 

allow operators of non-highway legal vehicles to operate on NFTS roads where such use is 

currently prohibited through the conversion of ML 3 roads (maintained for passenger cars) to 

ML 2 (maintained for high clearance vehicles).

c. Changes in Seasonal Restrictions: No changes in seasonal restrictions would be made.

d. Reopening Maintenance Level 1 Roads: Two Maintenance Level 1 roads (1.1 miles) would 

be reopened to motorized use.

Amendments to the Forest Plan: No amendments would be made to the Forest Plan.

Including the additions and changes described above, the Proposed Action would result in a system of 

2,068.5 miles of NFTS roads and 365.0 miles of NFTS motorized trails open to public motorized use. A 

more detailed description of the Proposed Action can be found in Chapter 2 (The Alternatives). A map of 

the Proposed Action is available on compact disc. Appendix A (Site Specific Road, Trail and Open Area 

Information) shows the specified vehicle class, season of use and any required mitigations associated with 

any facility added to the NFTS under this proposed action.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Summary

Tahoe National Forest – iii

Significant Issues _______________________________________

Internal and external scoping identified the following significant issues which were used in developing 

the action alternatives. The significant issues include the following:

Table S-1. Significant Issues

Issue/Element Cause and Effect

Significant Issue Statement #1. The route inventory identified approximately 1,596.3 miles of existing unauthorized 

routes and the Proposed Action only adds 36.7 miles of these to the NFTS. Reducing the miles of routes available for 

public motorized use and prohibiting cross country travel as described in the Proposed Action will adversely affect the 

quality and quantity of motorized recreation experiences

Motorized Recreation 

Opportunities

• Does not provide adequate access to key destinations, including campsites, scenic 

overlooks, and hunting areas.

• Reduces loops and connectors to provide longer riding time and spurs for exploration.

• Reduces the diversity of opportunities for different vehicles (ATVs, motorcycles, 

4WD).

• Reduces semi-primitive riding opportunities and experiences.

Significant Issue Statement #2. Public motorized use of roads and trails as described in the Proposed Action will 

adversely affect non-motorized recreation experiences.

Non-Motorized 

Recreation Opportunities

• Increases in engine noise will impact non-motorized recreation opportunities.

• Increases in dust will impact non-motorized recreation opportunities.

• Increases in motorized use will result in user conflicts between forest visitors.

• Increases in motorized use will reduce aesthetic values.

Significant Issue Statement #3. Public motorized use of roads and trails as described in the Proposed Action will 

adversely affect forest resources.

Resource Impacts • Increased erosion, soil compaction, and reduction in water quality;

• Degradation of habitat for fish, wildlife, and rare plants;

• Damage to heritage resources;

• Proliferation of weeds; and

• Impacts to Inventoried Roadless Area character compromising future potential 

wilderness designation.

Significant Issue Statement #4: The NFTS is already too large to provide adequate maintenance and 

administration. 

Affordability • Current and future budgets may not provide adequate funding for maintenance, 

administration and enforcement of the proposed road and trail system.

• Additions to the NFTS may require additional mitigation measures to prevent serious 

and adverse environmental impacts.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Summary

iv – Tahoe National Forest

Alternatives Considered in Detail __________________________

The TNF developed seven alternatives; the No Action, the Proposed Action, and 5 other action 

alternatives developed to meet the purpose and need and to respond to the significant issues listed above.

Alternative 6 is the Preferred Alternative. The seven alternatives considered in detail for this analysis are 

listed in Table S-2 below. Complete details of the alternatives are found in Chapter 2 of the SDEIS.

Table S-2. List of Alternatives Considered in Detail

Alternative 1: 

No Action 

Alternative

The No Action Alternative provides a baseline for comparing the other alternatives. Under the No 

Action Alternative, no changes would be made to the NFTS and there would be no prohibition of 

cross country travel. Current management plans would continue to guide project area 

management. The Travel Management Rule would not be implemented, and no motor vehicle use 

map (MVUM) would be published. Motor vehicle travel by the public would not be limited to 

designated routes. Unauthorized routes would continue to proliferate and would have no status or 

authorization as NFTS facilities.

Cross Country Travel: Does not prohibit motorized cross country travel.

Additions to the NFTS: No unauthorized routes added to the NFTS as roads or motorized trails 

under this alternative. 

Establishment of Motorized “Open Areas”: No additional motorized “Open Areas” 

established.

Changes to the NFTS: No changes to the NFTS made.

Amendments to the Forest Plan: No amendments made to the Forest Plan.

Alternative 2: 

Increased 

Motorized 

Recreation

and Access 

Opportunities

Alternative 2 responds to the issue of inadequate motorized recreation opportunities. This 

alternative is based on the Proposed Action (Alternative 7), with additional routes and mixed use 

to provide more access and motorized recreation opportunities. During scoping, the Tahoe 

National Forest received numerous site specific suggestions for additional motorized roads, trails 

and established “Open Areas” that would improve public access and enhance motorized 

recreation opportunities. Unauthorized routes and closed NFTS roads site-specifically requested 

by the public during scoping were added in this alternative, provided they were consistent with law, 

regulation, and policy. In addition, site specific recommendations for “Open Areas” proposed by 

the public during scoping were also established in this alternative provided they were consistent 

with law, regulation and policy.

Cross Country Travel: Prohibits motorized cross country travel.

Additions to the NFTS: Adds 5.0 miles (114 segments) of unauthorized routes to the NFTS as 

roads.

Adds 54.6 miles (87 segments) of unauthorized routes to the NFTS as motorized trails.

Establishment of Motorized “Open Areas”: Establishes four areas (2,649 acres) as 

motorized “Open Areas” open to all vehicles.

Changes to the NFTS: 

Allows 241.5 miles of mixed use.

Changes Class of Vehicles on 157.2 miles by changing maintenance levels.

Seasonal restrictions removed for deer winter range in Sugar Pine Area.

No Maintenance Level 1 roads reopened.

Amendments to the Forest Plan: Amendment made to remove deer winter seasonal 

restriction in Sugar Pine area.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Summary

Tahoe National Forest – v

Alternative 3: 

Cross Country 

Travel 

Prohibition 

Only – No 

Changes to 

the Existing 

National 

Forest 

Transportation 

System

Alternative 3 responds to issues of (1) adverse effects of motorized recreation use on nonmotorized recreation experiences and (2) potential adverse impacts from motorized recreation use 

on natural and cultural resources. This alternative provides a baseline for comparing the impacts 

of other alternatives that propose changes to the NFTS. 

Cross Country Travel: Prohibits motorized cross country travel.

Additions to the NFTS: No unauthorized routes added to the NFTS.

Establishment of Motorized “Open Areas”: No additional motorized “Open Areas” 

established. 

Changes to the NFTS: No changes to the NFTS made in this alternative.

Amendments to the Forest Plan: No amendments made to the Forest Plan.

Alternative 4: 

Increased 

Resource 

Protection

Alternative 4 responds to issues of (1) adverse effects of motorized recreation use on nonmotorized recreation experiences and (2) potential adverse impacts from motorized recreation use 

on natural and cultural resources. It addresses these issues by prohibiting cross country travel and 

adding fewer routes to the NFTS than the Proposed Action. Alternative 4 is based on the 

Proposed Action contained in the Notice of Intent as modified by an alternative submitted by an 

environmental group coalition during scoping.

Cross Country Travel: Prohibits motorized cross country travel.

Additions to the NFTS: Adds 3.7 miles (85 segments) of unauthorized routes to the NFTS as 

roads.

Adds 22.6 miles (27 segments) of unauthorized routes to the NFTS as motorized trails.

Establishment of Motorized “Open Areas”: No additional motorized “Open Areas” 

established.

Changes to the NFTS: 

Allows no mixed use.

Changes class of vehicles on 3.4 miles by changing maintenance levels.

Wet weather seasonal closures added on native surface roads and motorized trails. 

One Maintenance Level 1 road (.1 mile) reopened.

Amendments to the Forest Plan: No amendments made to the Forest Plan.

Alternative 5: 

Increased 

Motorized 

Recreation 

Access plus 

Reopening 

Maintenance 

Level 1 and 

Temporary 

Roads

Alternative 5 responds to the issue of inadequate motorized recreation opportunities. This 

alternative is based on the Proposed Action contained in the Notice of Intent as modified by an 

alternative submitted by the Blue Ribbon Coalition during the scoping process. This alternative 

focuses on adding unauthorized routes to the NFTS and making changes to the existing NFTS to 

provide enhanced motorized vehicle access and motorized recreation opportunities across the 

Forest.

Cross Country Travel: Prohibits motorized cross country travel.

Additions to the NFTS: Adds 5.0 miles (112 segments) of unauthorized routes to the NFTS as 

roads.

Adds 75.4 miles (141 segments) of unauthorized routes to the NFTS as motorized trails.

Establishment of Motorized “Open Areas”: No additional motorized “Open Areas” 

established.

Changes to the NFTS: 

Allows 241.5 miles of mixed use.

Changes class of vehicles on 157.2 miles by changing maintenance levels.

Wet weather seasonal closures added on native surface roads and motorized trails. 

113 Maintenance Level 1 roads (93.4 miles) reopened.

Amendments to the Forest Plan: Amendment to remove deer winter seasonal restriction in 

Sugar Pine area.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Summary

vi – Tahoe National Forest

Alternative 6: 

Preferred 

Alternative 

Motorized

Access

and Resource 

Protection

Alternative 6 is the Preferred Alternative. It responds to issues of providing motorized public 

access and recreation opportunities while minimizing impacts to natural and cultural resources. It 

is designed to provide a diversity of road and trail opportunities for experiencing a variety of 

environments and modes of travel consistent with the National Forest’s recreation role and land 

capability. Alternative 6 would provide motorized access to dispersed recreation opportunities and 

a diversity of motorized recreation opportunities 

Cross Country Travel: Prohibits motorized cross country travel.

Additions to the NFTS: Adds 13.1 miles (346 segments) of unauthorized routes to the NFTS 

as roads.

Adds 48.3 miles (106 segments) of unauthorized routes to the NFTS as motorized trails.

Establishment of Motorized “Open Areas”: Establishes three areas (244 acres) as motorized 

“Open Areas” open to highway-legal vehicles only.

Changes to the NFTS: 

Allows 130.8 miles of mixed use, 117.5 miles of which open only during deer hunting season.

Changes class of vehicles on 122.0 miles by changing maintenance levels.

Wet weather seasonal closures added on native surface roads and motorized trails. 

Thirteen Maintenance Level 1 roads (11.4 miles) reopened.

Amendments to the Forest Plan: Amendment to remove deer winter seasonal restriction in 

Sugar Pine area.

Alternative 7: 

Proposed 

Action as 

Identified in 

Notice of 

Intent (NOI)

Alternative 7 is the Proposed Action as published in the Notice of Intent in the Federal Register.

Cross Country Travel: Prohibits motorized cross country travel.

Additions to the NFTS: Adds 36.7 miles (36 segments) of unauthorized routes to the NFTS as 

motorized trails.

Establishment of Motorized “Open Areas”: No additional motorized “Open Areas” 

established.

Changes to the NFTS: 

Allows no mixed use.

Changes class of vehicles on 3.4 miles by changing maintenance levels.

No changes to seasonal restrictions.

Two Maintenance Level 1 roads (1.1 miles) reopened.

Amendments to the Forest Plan: No amendments made to the Forest Plan.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Summary

Tahoe National Forest – vii

Comparison of Alternatives _______________________________

The table below compares the activities that would occur under each alternative.

Table S-3. Comparison of Alternatives

Action type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

1. Cross Country Travel (Acres) Prohibitions 

continue on 

81,975 acres

Continues on 

754,066 acres

Prohibited on 

833,392 acres

2,649 acres 

established 

open

Prohibited on 

836,000 acres

<100 acres 

established 

open

Prohibited on 

836,000 acres

<100 acres 

established 

open

Prohibited on 

836,000 acres

<100 acres 

established 

open

Prohibited on 

835,800 acres

<300 acres 

established 

open

Prohibited on 

836,000 acres

<100 acres 

established 

open

2. Additions 

to the NFTS

a. Roads added to the NFTS

(Number of Miles)

(Number of Roads)

0.0

0

5.0

114

0.00

0

3.7

85

5.0

112

13.1

346

0.00

0

b. Motorized Trails added to the 

NFTS

(Number of Miles)

(Number of Trails)

0.0

0

54.6

87

0.0

0

22.6

27

75.4

141

48.3

106

36.7

36

3. Establishment of Motorized “Open Areas” None Greenhorn 

Area (60 

acres) 

Prosser, Boca 

and 

Stampede 

Reservoirs 

(2,589 acres)

None None None Prosser, Boca 

and 

Stampede 

Reservoirs 

(244 acres)

None
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Summary

viii – Tahoe National Forest

Action type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

4. Changes 

to the NFTS

a. Change in Class of Vehicles 

resulting from approval of mixed 

use

0.0 241.5 0.0 0.0 241.5 130.8 0.0

b. Change in Class of Vehicles 

resulting from changes in 

maintenance levels

0.0 157.2 0.00 3.4 157.2 122.0 3.4

c. Change in Season of Use 0.0 10.5 0.00 1,312.1 1,396.7 1,369.5 0.00

d. Reopening Maintenance Level 1 

Roads

(Number of Miles)

(Number of Roads) 

0.0

0

0.0

0

0.0

0

0.1

1

93.4

113

11.4

13

1.1

2

5. Amendments to the Forest Plan None Management 

Area 84 

(Humbug 

Sailor) Deer 

Winter Range 

Seasonal 

Restriction 

Removed

None None Management 

Area 84 

(Humbug 

Sailor) Deer 

Winter Range 

Seasonal 

Restriction 

Removed

Management 

Area 84 

(Humbug 

Sailor) Deer 

Winter Range 

Seasonal 

Restriction 

Removed

None
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Table of Contents

Tahoe National Forest – ix

Table of Contents

Summary......................................................................................................................................................ii

Proposed Action as Described in the Notice of Intent..............................................................................ii

Significant Issues.....................................................................................................................................iii

Alternatives Considered in Detail............................................................................................................ iv

Comparison of Alternatives....................................................................................................................vii

Chapter 1: Purpose and Need.................................................................................................................... 1

Document Structure.................................................................................................................................. 1

Background............................................................................................................................................... 1

Travel Management –Tahoe National Forest Transportation System.................................................................3

Corrections to the NFTS Data in the DEIS – Preparation of a Supplemental DEIS...........................................4

Project Location........................................................................................................................................ 6

Purpose and Need..................................................................................................................................... 6

Proposed Action as Described in the Notice of Intent.............................................................................. 9

Principle Laws and Regulations that influence the scope of this EIS .................................................... 10

Decision Framework .............................................................................................................................. 10

Public Participation ................................................................................................................................ 10

30-day public scoping period for the Notice of Intent ......................................................................................11

Issues ................................................................................................................................................... 11

Chapter 2: The Alternatives..................................................................................................................... 15

How the Alternatives Were Developed.................................................................................................. 15

Modifications to Alternatives between Draft and Supplemental Draft Environmental Impact

Statement................................................................................................................................... 15

Elements Common to All Alternatives................................................................................................... 16

Motorized Mixed Use .......................................................................................................................................16

Parking ............................................................................................................................................................17

Routine Maintenance ........................................................................................................................................17

Mitigation Measures.........................................................................................................................................18

Monitoring ........................................................................................................................................................19

Implementation Strategy...................................................................................................................................20

Alternatives Considered in Detail........................................................................................................... 20

Alternative 1: No Action...................................................................................................................................22

Alternative 2: Increased Motorized Recreation and Access Opportunities.......................................................23

Alternative 3: Cross Country Travel Prohibition Only – No Changes to the Existing National Forest 

Transportation System........................................................................................................................25

Alternative 4: Increased Resource Protection...................................................................................................26

Alternative 5: Increased Motorized Recreation Access plus Reopening Maintenance Level 1 and

Temporary Roads...............................................................................................................................28

Alternative 6: Preferred Alternative Motorized Access and Resource Protection ............................................29

Alternative 7: Proposed Action as Identified in Notice of Intent (NOI)...........................................................31
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Table of Contents

x – Tahoe National Forest

Alternatives Considered but Eliminated from Detailed Study ............................................................... 33

Alternative A: Prohibit OHV (Non-Highway Legal) Use ................................................................................33

Alternative B: Add All Unauthorized Routes to the System ............................................................................33

Alternative C: Trigger Seasonal Closure on and off throughout the Wet Season.............................................33

Alternative D: New Route Construction...........................................................................................................34

Alternative E: Non-Motorized ..........................................................................................................................34

Alternative F: Grandfather User-Created Routes into the NFTS and Conditionally Add Routes Pending 

Further Analysis and Mitigation.........................................................................................................34

Alternative G: Add All Routes Receiving OHV Use........................................................................................35

Alternative H: Close and Decommission NFTS Roads and Trails to Reduce Resource Impacts.....................35

Alternative I: Travel Corridors.........................................................................................................................35

Alternative J: Designate Staging Areas in Addition to Proposed Routes and NFTS Changes.........................36

Alternative K: Allow Cross Country Motorized Use off Designated Routes in order to Retrieve Legally 

Taken Big Game Animals..................................................................................................................36

Alternative L: Responsible Recreation Alternative ..........................................................................................36

Alternative M: Stewards of the Sierra Alternative............................................................................................37

Comparison of Alternatives.................................................................................................................... 37

Chapter 3: Affected Environment and Environmental Consequences................................................ 47

Introduction ............................................................................................................................................ 47

Analysis Process..................................................................................................................................... 47

Cumulative Effects................................................................................................................................. 49

Affected Environment Overview............................................................................................................ 50

Appendix A (Site Specific Road, Trail and Open Area Information).................................................... 50

Law Enforcement ................................................................................................................................... 50

Law Enforcement Assumptions Common to Effects Analysis:........................................................................51

Climate Change ...................................................................................................................................... 51

Short Term Uses and Long Term Productivity ...................................................................................... 52

Unavoidable Adverse Effects................................................................................................................. 52

Irreversible and Irretrievable Commitments of Resources..................................................................... 52

Incomplete and Unavailable Information............................................................................................... 53

Other Required Disclosures.................................................................................................................... 53

3.01. Air Quality........................................................................................................................................ 57

Regulatory Framework........................................................................................................................... 57

Affected Environment ............................................................................................................................ 58

Environmental Consequences................................................................................................................. 67

Summary of Effects Analysis across All Alternatives ........................................................................... 79

3.02. Watershed Resources: Geology, Soil, Hydrology.......................................................................... 81

Introduction ............................................................................................................................................ 81

Geology .................................................................................................................................................. 82

Regulatory Framework .....................................................................................................................................83

Affected Environment: Geology.......................................................................................................................85

Environmental Consequences: Geology ...........................................................................................................87
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Table of Contents

Tahoe National Forest – xi

Soil Resources........................................................................................................................................ 90

Introduction ......................................................................................................................................................90

Effects Analysis Methodology..........................................................................................................................92

Assumptions specific to the soil resources analysis..........................................................................................93

Data Sources.....................................................................................................................................................94

Soil Resources Indicators..................................................................................................................................94

Soil Resource Methodology by Action.............................................................................................................94

Affected Environment: Soil Resources.............................................................................................................99

Environmental Consequences: Soil Resources...............................................................................................103

Environmental Consequences by Alternative .................................................................................................107

Summary of Effects Analysis across All Alternatives....................................................................................113

Hydrology............................................................................................................................................. 114

Introduction ....................................................................................................................................................114

Analysis Framework: Statute, Regulation, Forest Plan, and Other Direction.................................................114

Effects Analysis Methodology........................................................................................................................115

Impacts relevant to water resources include ...................................................................................................116

Assumptions specific to the water resources analysis.....................................................................................116

Data Sources...................................................................................................................................................117

Water Resources Indicators............................................................................................................................117

Water Resources Methodology by Action:.....................................................................................................117

Affected Environment: Hydrology .................................................................................................................123

Environmental Consequences: Hydrology......................................................................................................130

Environmental Consequences by Alternative .................................................................................................141

Summary of Effects to Geologic, Soil and Hydrology Resources..................................................................150

Conclusion ......................................................................................................................................................150

3.03. Terrestrial and Aquatic Species.................................................................................................... 151

Introduction .......................................................................................................................................... 151

Analysis Framework: Statute, Regulation, Forest Plan and Other Direction ....................................... 151

Background on Effects to Terrestrial and Aquatic Habitat .................................................................. 154

Wildlife Effects Analysis Methodology............................................................................................... 158

Description of Indicators Used to Measure Effects of the Alternatives............................................... 165

Assumptions for Wildlife Effects Analysis.......................................................................................... 167

Sources of Information for Wildlife Effects Analysis.......................................................................... 168

Affected Environment and Environmental Consequences by Species Groups.................................... 168

Summary of Effects Analysis for All Species and Species Groups ..................................................... 170

Summary of Effects Common to All Species....................................................................................... 171

Wide-Ranging Carnivores Species Group:........................................................................................... 173

Affected Environment .......................................................................................................................... 173

Wide-Ranging Carnivores Species Group: Environmental Consequences.......................................... 174

Wide-ranging Carnivores Species Group: Cumulative Effects........................................................... 175

Black Bear: Affected Environment ...................................................................................................... 175

Black Bear: Environmental Consequences........................................................................................... 176

Wolverine and Sierra Nevada Red Fox: Affected Environment .......................................................... 184
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Table of Contents

xii – Tahoe National Forest

Wolverine and Sierra Nevada Red Fox: Environmental Consequences............................................... 185

Mule Deer (Ungulates): Affected Environment ................................................................................... 198

Mule Deer: Environmental Consequences........................................................................................... 202

Oak Woodland and Oak-Conifer Associated Species: Affected Environment .................................... 234

Oak Woodland and Oak-Conifer Associated Species: Environmental Consequences........................ 235

Fox Sparrow and Shrubland (West-Slope Chaparral) Habitat: Affected Environment........................ 238

Fox Sparrow: Environmental Consequences........................................................................................ 239

Mountain Quail (Early- and Mid-seral Coniferous Forest Associated Species): Affected

Environment ............................................................................................................................ 243

Mountain Quail: Environmental Consequences................................................................................... 244

Sooty (Blue) Grouse (Late-Seral Open Canopy Coniferous Forest): Affected Environment .............. 252

Sooty Grouse (Blue Grouse): Environmental Consequences............................................................... 253

Old Forest Conifer Associated Species: Affected Environment .......................................................... 259

Old Forest Conifer Associated Species: Environmental Consequences............................................... 260

Old Forest Emphasis Areas (OFEAs)................................................................................................... 268

Spotted Owl: Affected Environment.................................................................................................... 273

Spotted Owl: Environmental Consequences ........................................................................................ 274

Spotted Owl: Disturbance at a Specific Site......................................................................................... 276

Northern Goshawk: Affected Environment.......................................................................................... 308

Northern Goshawk: Environmental Consequences.............................................................................. 309

Forest Carnivores: American Marten, Pacific Fisher, Sierra Nevada Red Fox and Wolverine ........... 331

American Marten and Pacific Fisher: Affected Environment .............................................................. 331

American Marten and Pacific Fisher: Environmental Consequences .................................................. 335

Snags in Green Forest Ecosystem Component Associated Species: Affected Environment ............... 352

Snags in Green Forest Ecosystem Component Associated Species: Environmental Consequences.... 353

Aquatic and Riparian Associated Species............................................................................................ 360

Riparian Associated Bird Species......................................................................................................... 361

Bald Eagle: Affected Environment....................................................................................................... 362

Bald Eagle: Environmental Consequences........................................................................................... 363

Willow Flycatcher: Affected Environment .......................................................................................... 372

Willow Flycatcher: Environmental Consequences............................................................................... 373

Great Gray Owl: Affected Environment .............................................................................................. 385

Great Gray Owl: Environmental Consequences................................................................................... 386

Greater Sandhill Crane: Affected Environment ................................................................................... 396

Greater Sandhill Crane: Environmental Consequences........................................................................ 397

Yellow Warbler: Affected Environment .............................................................................................. 404

Yellow Warbler: Environmental Consequences................................................................................... 405

Aquatic Species and Habitat................................................................................................................. 414

Fisheries (trout) and Macroinvertebrates: Affected Environment........................................................ 415

Fisheries (trout) and Macroinvertebrates: Environmental Consequences............................................ 416

Lahontan Cutthroat Trout: Affected Environment ............................................................................... 424
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Table of Contents

Tahoe National Forest – xiii

Lahontan Cutthroat Trout: Environmental Consequences ................................................................... 425

Lahontan Lake Tui Chub: Affected Environment................................................................................ 439

Lahontan Lake Tui Chub: Environmental Consequences.................................................................... 440

Frogs ................................................................................................................................................. 450

California Red-legged Frog: Affected Environment ............................................................................ 451

California Red-legged Frog: Environmental Consequences ................................................................ 452

Foothill Yellow-legged Frog: Affected Environment .......................................................................... 455

Foothill Yellow-legged Frog: Environmental Consequences............................................................... 456

Mountain Yellow-Legged Frog: Affected Environment ...................................................................... 475

Mountain Yellow-Legged Frog: Environmental Consequences .......................................................... 475

Northwestern Pond Turtle: Affected Environment............................................................................... 492

Northwestern Pond Turtle: Environmental Consequences................................................................... 492

Sensitive Aquatic Mollusks.................................................................................................................. 505

Great Basin Ramshorn Snail: Affected Environment........................................................................... 505

Great Basin Ramshorn Snail: Environmental Consequences............................................................... 505

California Floater: ................................................................................................................................ 514

Affected Environment and Environmental Consequences................................................................... 514

Compliance with Forest Plan and Other Direction............................................................................... 514

Summary of Effects Analysis across All Alternatives ......................................................................... 516

3.04. Fire Fuels Management................................................................................................................. 517

Affected Environment .......................................................................................................................... 517

Environmental Consequences............................................................................................................... 519

Summary of Effects Analysis across All Alternatives ......................................................................... 521

3.05. Cultural Resources......................................................................................................................... 523

Introduction .......................................................................................................................................... 523

Analysis Framework: Statute, Regulation, Forest Plan and Other Direction ....................................... 523

Effects Analysis Methodology ............................................................................................................. 525

Cultural Resources: Affected Environment.......................................................................................... 528

Cultural Resources: Environmental Consequences.............................................................................. 539

Compliance with the Forest Plan and Other Direction......................................................................... 570

3.06. Plant Communities......................................................................................................................... 571

Introduction .......................................................................................................................................... 571

Analysis Framework: Statute, Regulation, Forest Plan and Other Direction ....................................... 571

Affected Environment .......................................................................................................................... 573

Environmental Consequences............................................................................................................... 594

Summary of Effects Analysis across All Alternatives ......................................................................... 653
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

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xiv – Tahoe National Forest

3.07. Recreation and Visual Resources ................................................................................................. 655

Recreation............................................................................................................................................. 655

Analysis Framework: Statute, Regulation, Forest Plan, and Other Direction.................................................655

Effects Analysis Methodology........................................................................................................................657

Recreation Measurement Indicators ...............................................................................................................658

Measurement Indicator 1: Consistency with LRMP.......................................................................................659

Measurement Indicator 2: Non-motorized recreation opportunity .................................................................659

Measurement Indicator 3: Motorized recreation opportunity .........................................................................662

Measurement Indicator 4: Type of motorized access to dispersed recreation.................................................666

Measurement Indicator 5: Impact of proposed changes to the NFTS on neighboring private and federal

lands (dust, noise, use conflicts).......................................................................................................666

Recreation: Affected Environment .................................................................................................................667

Recreation: Environmental Consequences......................................................................................................670

Visual Resources.................................................................................................................................. 704

Introduction ....................................................................................................................................................704

Analysis Framework: Statute, Regulation, Forest Plan, and Other Direction.................................................705

Effects Analysis Methodology........................................................................................................................707

Visual Resources Methodology by Management Action................................................................................708

Visual Resources: Affected Environment.......................................................................................................710

Visual Resources: Environmental Consequences...........................................................................................711

3.08. Transportation ............................................................................................................................... 721

Affected Environment .......................................................................................................................... 721

Analysis Framework: Statute, Regulation, Forest Plan, and Other Direction ...................................... 721

Effects Analysis Methodology ............................................................................................................. 726

Environmental Consequences............................................................................................................... 727

Summary of Effects Analysis across All Alternatives ......................................................................... 732

3.09. Inventoried Roadless Areas & Special Areas.............................................................................. 733

Analysis Framework: Statute, Regulation, Forest Plan and Other Direction ....................................... 733

Effects Analysis Methodology ............................................................................................................. 734

Inventoried Roadless Areas: Affected Environment ............................................................................ 737

Inventoried Roadless Areas: Environmental Consequences ................................................................ 745

Citizen Inventoried Roadless Areas (CIRAs): Affected Environment................................................. 765

Citizen Inventoried Roadless Areas: Environmental Consequences.................................................... 765

Wilderness: Affected Environment & Environmental Consequences.................................................. 770

Experimental Forests: Affected Environment ...................................................................................... 770

Experimental Forests: Environmental Consequences .......................................................................... 770

Designated and Proposed Wild and Scenic Rivers: Affected Environment........................................ 771

Wild and Scenic Rivers: Environmental Consequences....................................................................... 773

Research Natural Areas: Affected Environment and Environmental Consequences.......................... 777

Special Interest Areas: Affected Environment and Environmental Consequences............................. 777

Summary of Effects Analysis across All Alternatives ......................................................................... 778
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Table of Contents

Tahoe National Forest – xv

3.10. Adjacent Ownerships..................................................................................................................... 779

Affected Environment .......................................................................................................................... 779

Environmental Consequences............................................................................................................... 783

3.11. Society, Culture & Economy......................................................................................................... 797

Population and Demographics.............................................................................................................. 797

Employment and Income: Affected Environment................................................................................ 800

Employment and Income: Environmental Consequences.................................................................... 801

Environmental Justice .......................................................................................................................... 813

Environmental Justice: Affected Environment..................................................................................... 815

Environmental Justice: Environmental Consequences......................................................................... 819

Social Impact Analysis: Affected Environment ................................................................................... 821

Social Impact Analysis: Environmental Consequences ....................................................................... 823

Civil Rights Impact Analysis................................................................................................................ 824

Summary of Effects Analysis across All Alternatives ......................................................................... 827

Chapter 4: Consultation and Coordination.......................................................................................... 829

Truckee Pilot Project ............................................................................................................................ 829

Public Involvement Expanded to the Entire Forest.............................................................................. 829

Identifying Important Trail Criteria...................................................................................................... 830

Designing Public Involvement for Helping Develop Proposed Action................................................ 830

Workshops to Obtain Public Ideas on Proposed Action....................................................................... 830

Proposed Action and Notice of Intent to Prepare an Environmental Impact Statement....................... 830

Draft Environmental Impact Statement ............................................................................................... 831

Supplemental Draft Environmental Impact Statement......................................................................... 831

Relations with American Indian Tribes................................................................................................ 832

List of Preparers .................................................................................................................................. 833

Index
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Table of Contents

xvi – Tahoe National Forest

List of Tables

Table 1-1. Summary of corrections to the motorized recreation opportunities .............................................................5

Table 1-2. Summary of NFTS Mileage Before and After Corrections..........................................................................5

Table 1-3. Relation of Purpose and Need to Proposed Actions.....................................................................................8

Table 1-4. Significant Issues........................................................................................................................................12

Table 2‐1. Summary of Proposed Mitigation Measures by Alternative......................................................................18

Table 2-2. Summary of number of routes with monitoring requirements by resource category and alternative .........20

Table 2-3. Alternative 1 - Summary of Actions (Existing Condition).........................................................................23

Table 2-4. Alternative 2 - Summary of Actions ..........................................................................................................25

Table 2-5. Alternative 3 - Summary of Actions ..........................................................................................................26

Table 2-6. Alternative 4 - Summary of Actions ..........................................................................................................27

Table 2-7. Alternative 5 - Summary of Actions ..........................................................................................................29

Table 2-8. Alternative 6 - Summary of Actions ..........................................................................................................31

Table 2-9. Alternative 7 - Summary of Actions ..........................................................................................................32

Table 2-10. Summary of Proposed Actions by Alternative .........................................................................................38

Table 2-11. Summary Comparison of NFTS Road Mileage by Class of vehicle and Season of Use..........................40

Table 2-12. Summary Comparison of NFTS Motorized Trail Mileage by Class of Vehicle and Season of Use ........41

Table 2-13. Criteria for additions to the NFTS, re-opening Maintenance Level 1 roads and establishing lands as 

“Open Areas” ................................................................................................................................................42

Table 2-14. Comparison Summary of Effects to All Resources across All Alternatives.............................................43

Table 2-15. Summary comparison of key environmental outputs and effects for specific resources by alternative ...44

Table 3.01-1. Area Designation for State and Federal Standards for PM10 and Ozone..............................................64

Table 3.01-2. Motor vehicle use on native surface roads, trails and areas “most likely” to contain naturally

occurring asbestos.........................................................................................................................................67

Table 3.01-3. 2006 Estimated Annual Average Emissions for Off-Road Recreational Vehicles (tons per day).........68

Table 3.01-4. Amount of Native Surface Roads, Trails and Areas Open to Motorized Vehicles................................69

Table 3.01-5. Native Surface Roads, Trails and Areas Open to Motorized Vehicles on Lands “Most Likely” to 

Contain Naturally Occurring Asbestos..........................................................................................................75

Table 3.01-6. Comparison of Effects to Air Quality....................................................................................................79

Table 3.02-1. Paleontological sites currently identified on the Tahoe National Forest ...............................................86

Table 3.02-2. Ground Water Resources Potentially Impacted By Unauthorized or Closed NFTS Routes .................87

Table 3.02-3. Paleontological resources on the TNF potentially impacted by motorized vehicles by alternative.......88

Table 3.02-4. Mitigation measures to protect groundwater resources by alternative ..................................................88

Table 3.02-5. Number of Abandoned Mine Land (AML) Sites within 100 Feet of NFTS Roads and Motorized

Trails by Alternative......................................................................................................................................89

Table 3.02-6. Changes in the number AML sites within 100 feet of motorized vehicle access due to the

prohibition of cross country travel ................................................................................................................89

Table 3.02-7. Changes in AML sites within 100 feet of roads and motorized trails due to additions to the

NFTS.............................................................................................................................................................89

Table 3.02-8. Native surface road and trails (higher risk routes) by Erosion Hazard Rating1...................................101

Table 3.02-9. Percent of Inventoried Routes by Route Condition Class ...................................................................103

Table 3.02-10. Native surface road and motorized trails (high risk routes) by Erosion Hazard Rating ....................106

Table 3.02-11. Comparison of Effects to the Soil Resource......................................................................................113
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Table of Contents

Tahoe National Forest – xvii

Table 3.02-12. Sediment yields from reservoir surveys, suspended sediment records, and other estimates 

(Kattelmann, 1996)......................................................................................................................................124

Table 3.02-13. Impaired Water Bodies on the TNF Listed on the EPA 303(d) List .................................................125

Table 3.02-14. Miles and density of native surface roads and motorized trails in RCAs by major river basin and

the number and density of native surface road and motorized trail perennial and intermittent stream 

crossings by major river basin.....................................................................................................................126

Table 3.02-15. EMDS Erosion Risk rating and density of native surface roads and motorized trails by major

river basin....................................................................................................................................................129

Table 3.02-16. Watersheds and acres that are currently over the Threshold of Concern...........................................130

Table 3.02-17. 303(d) listed water bodies, the reason for listing and potential impacts............................................133

Table 3.02-18. Miles and density of native surface roads and motorized trails in RCAs by alternative (Density

mi per square mile of RCA) ........................................................................................................................137

Table 3.02-19. Number and density of native surface road and motorized trail stream crossings by alternative 

(Density, number of crossings per square mile of RCA).............................................................................138

Table 3.02-20. Erosional features (miles) on proposed routes by alternative............................................................138

Table 3.02-21. Density of “Higher Risk Routes” by major river basin by alterative (mi./sq. mi.)............................139

Table 3.02-22. Native surface roads and native trails by Alternative and Density Class ..........................................140

Table 3.02-23. Equivalent Road Acres associated with roads and trails due to cumulative effects of all

proposed actions (ERA percents of watershed)...........................................................................................141

Table 3.02-24. Comparison of Effects to Hydrology Resources...............................................................................149

Table 3.03-1. List of Tahoe NF Special Status Species by Habitat Indicator and Distribution1...............................158

Table 3.03-2. Species group and species represented within groups.........................................................................162

Table 3.03-3 lists the road and trail-associated response classifications, response factors and definitions, and

affected species groups................................................................................................................................163

Table 3.03-4. Generalized effects of motorized route densities (proportion of Tahoe NF acreage) between

0 miles per square mile and greater than 6 miles per square mile (averaged by 7th field watershed)..........172

Table 3.03-5. Proportion of Black Bear Habitat within a 274-meter “Zone of Influence” of Motorized Routes......178

Table 3.03-6. Black Bear: Summary of Overall Net Direct and Indirect Effect........................................................179

Table 3.03-7. Black Bear: Percentage of Tahoe NF within high, moderate, and low habitat capability ...................181

Table 3.03-8. Black Bear: Cumulative Effects Summary..........................................................................................182

Table 3.03-9. Percent of NFS lands within a 60 meter “Zone of Influence” of motorized route additions and 

reopened ML 1 roads within Old Forest Habitat (CWHR 4M, 4D, 5M, 5D, and 6)...................................187

Table 3.03-10. Miles of Proposed Motorized Route Addition to the NFTS and Existing Unauthorized

Motorized Routes within 5 miles of Known Verified Wolverine Detections..............................................188

Table 3.03-11. Miles and Zone of Influence of Reopened Maintenance Level 1 Roads within 5 miles of

Known Verified Wolverine Detections.......................................................................................................189

Table 3.03-12. Wolverine and Sierra Nevada Red Fox: Summary of Overall Net Direct and Indirect Effects ........190

Table 3.03-13. Percent of Tahoe NF with motorized route densities between zero and greater than 6

miles/square mile.........................................................................................................................................193

Table 3.03-14. Wolverine and Sierra Nevada Red Fox Cumulative effects from Motorized Route Density,

Habitat Fragmentation, and Disturbance to a Specific Site .........................................................................194

Table 3.03-15. Mule Deer Acreage of Habitat by type for each major deer herd within Tahoe NF boundary..........199

Table 3.03-16. Tahoe Forest Plan Motor Vehicle Deer Seasonal Restrictions by Management Area (MA) ............203

Table 3.03-17. Miles of Motorized Route Additions on within deer herd winter ranges, critical winter ranges,

critical summer, and fawning areas on the Tahoe NF .................................................................................205

Table 3.03-18. Percent of Key Deer Ranges within a 200-meter “Zone of Influence” of Motorized Route

Additions by Herd .......................................................................................................................................207
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Table of Contents

xviii – Tahoe National Forest

Table 3.03-19. Miles of Reopened Maintenance Level 1 Roads within Key Deer Habitats .....................................209

Table 3.03-20. Percent of Key Deer Ranges within a 200-meter “Zone of Influence” of Reopened

Maintenance Level 1 Roads by Herd ..........................................................................................................210

Table 3.03-21. Blue Canyon Deer Herd - Key Deer Winter Range Summary for Alternatives 2, 5, and 6 ..............212

Table 3.03-22. Motorized Season of Use within Blue Canyon Herd Key Deer Winter Range .................................212

Table 3.03-23. Zone D-4 Deer Population Numbers 1999-2008...............................................................................214

Table 3.03-24. Mule Deer - Summary of Overall Net Direct and Indirect Effects....................................................216

Table 3.03-25. Average route densities (miles/square mile) on NFS lands within deer herd winter ranges,

critical winter ranges, critical summer, and fawning areas on the Tahoe NF..............................................219

Table 3.03-26. Cumulative Motorized Route Miles..................................................................................................221

Table 3.03-27. Proportion of Blue Canyon Herd Key Deer Ranges within a 200-meter “Zone of Influence”..........222

Table 3.03-28. Proportion of Downieville Herd Key Deer Ranges within a 200-meter “Zone of Influence”...........224

Table 3.03-29. Proportion of Nevada City Herd Deer Ranges within a 200-meter “Zone of Influence” ..................226

Table 3.03-30. Proportion of Loyalton-Truckee Herd Key Deer Ranges within a 200-meter “Zone of

Influence”....................................................................................................................................................228

Table 3.03-31. Direct, Indirect, and Cumulative Impact to Mule Deer from Reasonably Foreseeable Future

Projects........................................................................................................................................................230

Table 3.03-32 Acres of Cross Country Travel Prohibitions and Proportion of Mule Deer MIS habitat within

a 200-meter “Zone of Influence” of Proposed Route Additions to the NFTS.............................................232

Table 3.03-33. Oak and Oak/Conifer Habitat - Summary of Overall Net Direct and Indirect Effects......................237

Table 3.03-34. Proportion of Oak Habitat (Percent) with Motorized Route Densities between 0 and 6

miles/square mile.........................................................................................................................................238

Table 3.03-35. Proportion of Fox Sparrow MIS habitat within a 200-meter “Zone of Influence” of Proposed

Route Additions...........................................................................................................................................240

Table 3.03-36. Proportion of Fox Sparrow MIS habitat within a 200-meter “Zone of Influence” of Reopened

ML 1 Roads.................................................................................................................................................240

Table 3.03-37. Fox Sparrow - Summary of Overall Net Direct and Indirect Effects ................................................241

Table 3.03-38. Proportion of Mountain Quail Early-seral Coniferous Forest MIS habitat within a 200-meter

“Zone of Influence” of Proposed Motorized route additions to the NFTS..................................................245

Table 3.03-39. Proportion of Mountain Quail Mid-seral Coniferous Forest MIS habitat within a 200-meter

“Zone of Influence” of Proposed Motorized route Additions to the NFTS.................................................246

Table 3.03-40. Proportion of Mountain Quail Early-seral Coniferous Forest MIS habitat within a 200-meter

“Zone of Influence” of Reopened Maintenance Level 1 Roads..................................................................246

Table 3.03-41. Proportion of Mountain Quail Mid-seral Coniferous Forest MIS habitat within a 200-meter

“Zone of Influence” of Reopened Maintenance Level 1 Roads..................................................................247

Table 3.03-42. Mountain Quail - Summary of Overall Net Direct and Indirect Effects............................................248

Table 3.03-43. Direct, Indirect, and Cumulative Impact of Reasonably Foreseeable Future Projects ......................250

Table 3.03-44. Proportion of Sooty (Blue) Grouse Late-seral Open Canopy Coniferous Forest MIS habitat

within a 200-meter “Zone of Influence” of Proposed Motorized route Additions to the NFTS..................254

Table 3.03-45. Proportion of Sooty (Blue) Grouse Late-seral Open Canopy Coniferous Forest MIS habitat

within a 200-meter “Zone of Influence” of Reopened Maintenance Level 1 Roads...................................254

Table 3.03-46. Sooty Grouse- Summary of Overall Net Direct and Indirect Effects................................................255

Table 3.03-47. Sooty Grouse Direct, Indirect, and Cumulative Impact of Reasonably Foreseeable Future

Projects........................................................................................................................................................257

Table 3.03-48. Proportion of Old Forest Habitat (CWHR 4M, 4D, 5M, 5D, and 6) within 200 Meters of

Motorized Route Additions and Reopened ML 1 Roads.............................................................................264

Table 3.03-49. Old Forest CWHR Habitat- Summary of Overall Net Direct and Indirect Effects ...........................265
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Table of Contents

Tahoe National Forest – xix

Table 3.03-50. Proportion of Late-seral Coniferous Forest Habitat (CWHR types 4M, 4D, 5M, 5D, and 6) with 

motorized route densities between 0 and 6 miles/square mile (Average motorized route densities

within 7th Field Watersheds)........................................................................................................................266

Table 3.03-51. Cumulative Effects for Percent of Old Forest Conifer Habitat (CWHR 4M, 4D, 5M, 5D, 6)

within 200 meters of All Routes..................................................................................................................267

Table 3.03-52. Old Forest Emphasis Areas (OFEAs) - Summary of Overall Net Direct and Indirect Effects..........270

Table 3.03-53. Proportion of Old Forest Emphasis Areas with motorized route densities between 0 miles per

square mile and greater than 6 miles per square mile (average motorized route densities within 7th field 

watersheds)..................................................................................................................................................271

Table 3.03-54. Cumulative Effects to Old Forest Emphasis Areas within a 200-meter Zone of Influence of

All Routes....................................................................................................................................................272

Table 3.03-55. Miles of Motorized Route Additions within 0.25 miles of Spotted Owl Activity Centers (Nest

Site or Nest Stand) by PAC Number and Route ID.....................................................................................277

Table 3.03-56. Miles of Reopened ML 1 Roads within 0.25 Miles of Spotted Owl Activity Center by PAC

Number and Road Number..........................................................................................................................278

Table 3.03-57. Miles of Motorized Route Additions by Spotted Owl PAC and Route ID........................................278

Table 3.03-58. Miles of Proposed Motorized route additions to the NFTS within Spotted Owl Protected

Activity Centers on the Tahoe NF...............................................................................................................280

Table 3.03-59. Miles of Reopened ML 1 Roads within PACs by Spotted Owl PAC Number and Road Number....280

Table 3.03-60 Level of Contribution to Disturbance to Spotted Owl by Specific PAC for Route Additions

and Reopened ML 1 Roads.........................................................................................................................282

Table 3.03-61. California spotted owl: summary of risk of increased disturbance to Activity Centers within

PACs ...........................................................................................................................................................286

Table 3.03-62. Miles of Motorized Route Additions to the NFTS within Tahoe NF Spotted Owl HRCAs..............288

Table 3.03-63. Miles of Motorized Route Additions by HRCAs and Route ID........................................................288

Table 3.03-64. Miles of Reopened ML 1 Roads within HRCAs by HRCA ID Number and Road Number.............290

Table 3.03-65. Cumulative Miles of Routes within a .25 Mile Radius Circle of Spotted Owl Activity Centers 

(Nest/Roost Sites)........................................................................................................................................294

Table 3.03-66. Cumulative Miles of Motorized and Non-motorized Routes within Spotted Owl Protected

Activity Centers...........................................................................................................................................295

Table 3.03-67. Cumulative Miles of Motorized and Non-motorized Routes within Spotted Owl Home Range

Core Areas...................................................................................................................................................296

Table 3.03-68. Proportion of Spotted Owl PACs within 200 Meters of Motorized Route Additions and

Reopened ML 1 Roads................................................................................................................................299

Table 3.03-69. Cumulative Effects - Proportion of Spotted Owl Protected Activity Centers within 200 meter

Zone of Influence of All Routes..................................................................................................................300

Table 3.03-70. Proportion of California Spotted Owl Home Range Core Areas (HRCAs) within 200 Meters 

influenced by Motorized Route Additions and Reopened ML 1 Roads......................................................301

Table 3.03-71. Cumulative Effects - Proportion of California Spotted Owl Home Range Core Areas (HRCAs)

within a 200-meter Zone of Influence .........................................................................................................302

Table 3.03-73. California Spotted Owl - Summary of Direct and Indirect Effects (PACs, HRCAs, and 0.25

mile radius of Activity Centers) ..................................................................................................................306

Table 3.03-74. Miles of Proposed Motorized Route Additions and Reopened ML 1 Roads within 0.25 Mile

Radius Circle of Northern Goshawk Activity Center (Nest Site or Nest Stand).........................................311

Table 3.03-75. Northern Goshawk PACs - Miles of Motorized Route Additions by PAC ID and Route ID............313

Table 3.03-76. Miles of Reopened ML 1 Roads by Northern Goshawk PAC and Route ID ....................................314

Table 3.03-77 Level of Contribution to Disturbance to Northern Goshawk by Specific PAC for Route

Additions and Reopened ML 1 Roads.........................................................................................................316

Table 3.03-78. Northern goshawk: summary of risk of increased disturbance to Activity Centers within PACs.....318
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Table of Contents

xx – Tahoe National Forest

Table 3.03-79. Northern Goshawk - Summary of Overall Net Direct and Indirect Effects.......................................320

Table 3.03-80. Cumulative Miles of All Routes within Tahoe NF Goshawk PACs .................................................323

Table 3.03-81. Miles of All Routes within 0.25 mile of Tahoe NF Goshawk Activity Centers (nest site or nest

stand)...........................................................................................................................................................325

Table 3.03-82. Cumulative Effects - Proportion of Goshawk Protected Activity Centers within a 400-meter

(0.25 mile) Zone of Influence of All Routes...............................................................................................328

Table 3.03-83. Percent of Carnivore Network, OFEAs, and Old Forest Habitat (CWHR 4M, 4D, 5M, 5D, 6)

within a 300-meter “Zone of Influence” of motorized route additions to the NFTS...................................337

Table 3.03-84. Percent of Carnivore Network, OFEAs, and Old Forest Habitat (CWHR 4M, 4D, 5M, 5D, 6)

within a 300-meter “Zone of Influence” of reopened ML 1 roads..............................................................337

Table 3.03-85. Meadows Intersected by Motorized Route Additions to the NFTS...................................................338

Table 3.03-86. Meadows Intersected by Reopened ML 1 Roads..............................................................................338

Table 3.03-87. American marten and Pacific fisher - Summary of Overall Net Direct and Indirect Effects ............339

Table 3.03-88. Proportion of Tahoe NF Lands with Motorized Route Densities greater than 2 miles/square

mile within Old Forest CWHR type, Old Forest Emphasis Areas, and Tahoe Carnivore Network ............342

Table 3.03-89. Cross Country Travel Cumulative Effects in Carnivore Network, OFEAs, and Old Forest

CWHR habitat.............................................................................................................................................343

Table 3.03-90. Cumulative Percent of Carnivore Network within a 300-meter Zone of Influence of Routes ..........344

Table 3.03-91. Cumulative Percent of Old Forest Emphasis Areas within a 300-meter Zone of Influence..............345

Table 3.03-92. Cumulative Percent of Forest-wide Late-seral Forest (CWHR 4, 5, 6) within 300-meter “Zone

of Influence” of Routes ...............................................................................................................................346

Table 3.03-93. Cumulative Number of Wet Meadows Intersected by Routes ..........................................................347

Table 3.03-94. Cross Country Travel and Proportion of Snags in Green Forest Hairy Woodpecker habitat

within a 60-meter “Zone of Influence” of Motorized Route Additions and Reopened ML 1 Roads to

the NFTS .....................................................................................................................................................355

Table 3.03-95. Hairy Woodpecker - Summary of Overall Net Direct and Indirect Effects.......................................356

Table 3.03-96. Direct, Indirect, and Cumulative Impact of Reasonably Foreseeable Future Projects ......................358

Table 3.03-97. Establishment of “Open Areas” to Access Reservoirs ......................................................................364

Table 3.03-98. Miles of Motorized Routes added to the NFTS within 0 to 400 meters and within 400 to 800

meters of Bald Eagle Nest Site....................................................................................................................366

Table 3.03-99. Bald Eagle - Summary of Overall Net Direct and Indirect Effects ...................................................368

Table 3.03-100. Cumulative Effects of Motorized Routes within 0 to 400 meters of Bald Eagle Nest Sites............371

Table 3.03-101 Cumulative Effects of Motorized Route miles within 400 to 800 meters of Bald Eagle Nest

Sites.............................................................................................................................................................372

Table 3.03-102. Willow flycatcher sites with unauthorized routes, prohibited to cross country travel.....................375

Table 3.03-103. Number of willow flycatcher meadow sites intersected by motorized route additions...................376

Table 3.03-104. Miles of Motorized Route Additions with willow flycatcher Emphasis Meadows by Route ID ....376

Table 3.03-105. Willow Flycatcher - Summary of Overall Net Direct and Indirect Effects.....................................378

Table 3.03-106. Cumulative Effects to Willow Flycatcher Meadows - Occupied and Emphasis Meadows

Intersected by Routes ..................................................................................................................................383

Table 3.03-107. Number of Great Gray Owl Meadows Intersected by Motorized Route Additions ........................388

Table 3.03-108. Number of Great Gray Owl Meadows Intersected by Reopened ML 1 Roads ...............................388

Table 3.03-109. Great Gray Owl - Summary of Overall Net Direct and Indirect Effects of the Alternatives...........390

Table 3.03-110. Cumulative Effects (Great Gray Owl Suitable Sites)......................................................................393

Table 3.03-111. Sandhill Crane - Summary of Overall Net Direct and Indirect Effects of the Alternatives.............400

Table 3.03-112 Proportion of Yellow Warbler MIS habitat affected by Motorized Route Additions.......................406

Table 3.03-113. Proportion of Yellow Warbler MIS habitat affected by Reopened ML 1 Roads.............................407
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Table of Contents

Tahoe National Forest – xxi

Table 3.03-114. Yellow Warbler Montane Riparian Habitat - Summary of Overall Net Direct and Indirect

Effects .........................................................................................................................................................408

Table 3.03-115. Direct, Indirect, and Cumulative Impact of Reasonably Foreseeable Future Projects ....................411

Table 3.03-116. Number of Native Surfaced, Stream Crossings Associated with Additions to the NFTS ...............417

Table 3.03-117. Miles of Route Additions within Riparian Conservation Areas (RCAs).........................................418

Table 3.03-118. Change in Class of Vehicle Impacts to Riverine and Lacustrine Habitats ......................................418

Table 3.03-119. Riverine and Lacustrine Habitat Effects from Reopened ML 1 Road.............................................419

Table 3.03-120. Summary of Effects from Motorized Route Additions to the NFTS, Reopened ML 1 Roads

and Changes in Maintenance Levels...........................................................................................................419

Table 3.03-121. Summary of Effects to Aquatic Macroinvertebrate Habitat Factors for the Alternatives................420

Table 3.03-122. Net Direct, Indirect, and Cumulative Effects to Number of Native Surfaced, Stream Crossings

from Motorized Route Crossing Additions, Cross Country Travel, and Change in Maintenance

Level, and Reopened ML 1 Roads..............................................................................................................422

Table 3.03-123. Net Direct, Indirect, and Cumulative Effects to Native Surfaced, RCA Miles from Motorized

Route Additions to the NFTS, Prohibition of Cross Country Travel, and Change in Class of Vehicles.....422

Table 3.03-124. Lahontan cutthroat trout 7th Field Watersheds - Number of Native Surfaced, Stream

Crossings Associated with Motorized Route Additions to the NFTS .........................................................428

Table 3.03-125. Miles of Proposed Route Additions within LCT HUC7 Riparian Conservation Areas (RCAs) .....429

Table 3.03-126. Effects to LCT 7th Field Watersheds from Change in Class of Vehicles.........................................432

Table 3.03-127. LCT 7th Field Watersheds – Summary of Direct, Indirect, and Cumulative Effect of

Proposed Actions as Measured by Native Surfaced, Motorized Stream Crossings.....................................435

Table 3.03-128. LCT 7th Field Watersheds – Summary of Direct, Indirect, and Cumulative Effect of

Proposed Actions as Measured by Native Surfaced, Motorized RCA Motorized Miles.............................437

Table 3.03-129. Lahontan Lake tui chub 7th Field Watersheds (Prosser, Stampede, Boca Reservoirs) -

Number of Native Surfaced, Stream Crossings Associated with Motorized Route Additions....................442

Table 3.03-130. Tui Chub - Miles of Proposed Route Additions within Prosser, Stampede, and Boca HUC7

Riparian Conservation Areas (RCAs) .........................................................................................................443

Table 3.03-131. Lahontan Lake Tui Chub – Effects from Change in Class of Vehicles...........................................443

Table 3.03-132. Number of HUC7 Watersheds with Suitable Lahontan Lake Tui Chub Habitat by RCA Route 

Density Category.........................................................................................................................................444

Table 3.03-133. Number and percent of HUC7 Watersheds with Suitable Lahontan Lake Tui Chub Habitat

by Native Surfaced, Motorized Stream Crossing Density Category ...........................................................446

Table 3.03-134. Lahontan Lake Tui Chub 7th Field Watersheds – Summary of Direct, Indirect, and

Cumulative Effect of Proposed Actions......................................................................................................448

Table 3.03-135. RCA miles and Stream Crossings Prohibited to Cross Country Travel ..........................................458

Table 3.03-136. Foothill Yellow-legged Frog 7th Field Watersheds - Number of Native Surfaced, Stream

Crossings Associated with Motorized Route Additions..............................................................................458

Table 3.03-137. RCA Miles of Proposed Route Additions within FYLF HUC7 Watersheds...................................459

Table 3.03-138. Foothill Yellow Legged Frog – Effects from Change in Class of Vehicles....................................459

Table 3.03-139. Direct and indirect effects of proposed motorized route additions and prohibition of cross

country travel in relation to known FYLF locations by 7th field watershed ................................................460

Table 3.03-140. Number and proportion of Foothill Yellow-legged Frog 7th Field Watersheds within Route

Density Categories of Highest, Moderately High, Moderately Low, and Lowest or Forty two 7th

Field Watersheds (HUC7s) with Foothill Yellow-legged Frog Observations.............................................466

Table 3.03-141. Number and Proportion of Foothill Yellow-legged Frog 7th Field Watersheds within Route

Crossing Density Categories of Highest, Moderately High, Moderately Low, and Lowest or Forty

one HUC7s with Foothill Yellow-legged Frog Observations .....................................................................467

Table 3.03-142. Foothill Yellow-legged Frog 7th Field Watersheds – Summary of Direct, Indirect, and

Cumulative Effect of Proposed Actions as Measured by Native Surfaced, Motorized Crossings ..............471
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xxii – Tahoe National Forest

Table 3.03-143. Foothill Yellow-legged Frog 7th Field Watersheds – Summary of Direct, Indirect, and

Cumulative Effect of Proposed Actions as Measured by RCA Motorized Route Miles.............................473

Table 3.03-144. Mountain Yellow-legged Frog 7th Field Watersheds - Number of Native Surfaced, Stream

Crossings Associated with Motorized Route Additions and Cross Country Prohibitions...........................477

Table 3.03-145. RCA Miles of Proposed Route Additions and Cross Country Prohibitions within MYLF

HUC7 Watersheds.......................................................................................................................................478

Table 3.03-146. Mountain Yellow-Legged Frog – as a Result of the Change in Class of Vehicles as Measured

by Native Surfaced, Motorized Crossings and Motorized Route Miles......................................................478

Table 3.03-147. Direct and indirect impacts of proposed motorized route additions in relation to known

mountain yellow-legged frog locations by 7th field watersheds..................................................................480

Table 3.03-148. Number 7th Field Watersheds (HUC7s) with Mountain Yellow-legged Frog Sites by RCA

Route Density Category or Number (Percent) of HUC7s by Route Density Category (n=25)...................482

Table 3.03-149. Number (Percent) 7th Field Watersheds (HUC7s) with Mountain Yellow-legged Frog Sites

by Native Surfaced, Motorized Crossing Density Category........................................................................484

Table 3.03-150. Mountain Yellow-legged Frog 7th Field Watersheds – Summary of Direct, Indirect, and

Cumulative Effect of Proposed Actions as Measured by Native Surfaced, Motorized Crossings ..............488

Table 3.03-151. Mountain Yellow-legged Frog 7th Field Watersheds – Summary of Direct, Indirect, and

Cumulative Effect of Proposed Actions as Measured by RCA Motorized Route Miles.............................490

Table 3.03-152. Cross Country Travel on Native, Surfaced Routes within NWPT 7th Field Watersheds.................494

Table 3.03-153. Northwestern Pond Turtle 7th Field Watersheds - Number of Native Surfaced, Stream

Crossings Associated with Motorized Route Additions..............................................................................494

Table 3.03-154. Northwestern Pond Turtle - Miles of Proposed Route Additions within HUC7 Watersheds..........495

Table 3.03-155. Description of motorized route additions for the action alternatives in relation to known 

northwestern pond turtle locations within 7th field watersheds ...................................................................496

Table 3.03-156. Number and Percent of 7th Field Watersheds (HUC7s) with Occupied Northwestern Pond

Turtle Locations by Route Density Category ..............................................................................................498

Table 3.03-157. Number of 7th Field Watersheds (HUC7s) with Occupied Northwestern Pond Turtle

Locations by Stream Crossing Density Category of Native Surfaced Routes.............................................499

Table 3.03-158. Northwestern Pond Turtle 7th Field Watersheds – Summary of Direct, Indirect, and

Cumulative Effect of Proposed Actions as Measured by Native Surfaced, Motorized Crossings ..............501

Table 3.03-159. Northwestern Pond Turtle 7th Field Watersheds – Summary of Direct, Indirect, and

Cumulative Effect of Proposed Actions as Measured by RCA Motorized Route Miles.............................503

Table 3.03-160. Cross Country Travel within Twelve GBRS 7th Field Watersheds .................................................507

Table 3.03-161. Great Basin Ramshorn Snail HUC7 Watersheds - Number of Native Surfaced, Stream

Crossings Associated with Motorized Route Additions to the NFTS .........................................................507

Table 3.03-162. Miles of Proposed Motorized Route Additions within twelve GBRS HUC7 Watersheds..............508

Table 3.03-163. Great Basin Ramshorn Snail (12 HUC7s) –Change in Class of Vehicles as Measured by

changes Native Surfaced, Motorized Crossings and Motorized Route Miles .............................................508

Table 3.03-164. Great Basin Ramshorn Snail 7th Field Watersheds – Summary of Direct, Indirect, and

Cumulative Effect of Proposed Actions as Measured by Native Surfaced, Motorized Crossings ..............510

Table 3.03-165. Great Basin Ramshorn Snail 7th Field Watersheds – Summary of Direct, Indirect, and

Cumulative Effect of Proposed Actions as Measured by RCA Motorized Route Miles.............................512

Table 3.03-166. Comparison of Effects to Terrestrial Species..................................................................................516

Table 3.03-167. Comparison of Effects to Aquatic and Riparian Species.................................................................516
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Tahoe National Forest – xxiii

Table 3.04-1. TNF Acres burned in by size of fire ....................................................................................................518

Table 3.04-2. Risk Assessment Categories Used For Human Caused Fire ...............................................................520

Table 3.04-3. Changes in Risk of Human Caused Wildfire by Alternative...............................................................521

Table 3.04-4. Access for fire suppression equipment by alternative .........................................................................521

Table 3.04-5. Comparison of Effects to Fire and Fuels.............................................................................................522

Table 3.05-1. Cultural Resource Sites within the Tahoe National Forest..................................................................529

Table 3.05-2. Cultural Resource Survey Miles and Acres within APE.....................................................................530

Table 3.05-3. Summary of Cultural Resources within the APE ................................................................................532

Table 3.05-4. Cultural Resource Sites Associated with Multiple Routes within the APE by Alternative.................536

Table 3.05-5. Summary of Cultural Resource Sites within the APE.........................................................................537

Table 3.05-6. Examples of Site Effects Documented at Cultural Resource Sites at Risk..........................................537

Table 3.05-7. Severity of Effects Definitions............................................................................................................538

Table 3.05-8. At-Risk Sites Summarized According to Type and Severity of Effect based on Alternative 1...........539

Table 3.05-9. Site Specific Motorized Effects on Cultural Resources at Risk by Alternative...................................542

Table 3.05-10. Summary Comparison of Effect, Type, and Severity on At Risk Cultural Resources ......................549

Table 3.05-11. Summary of Effects to Cultural Resources at Risk: Alternative 1 ....................................................550

Table 3.05-12. Summary of Effects to Cultural Resources at Risk: Alternative 2 ....................................................555

Table 3.05-13. Summary of Effects to Cultural Resources at Risk: Alternative 4 ....................................................560

Table 3.05-14. Summary of Effects to Cultural Resources at Risk: Alternative 5 ....................................................561

Table 3.05.15. Summary of Effects to Cultural Resources at Risk: Alternative 6.....................................................565

Table 3.05.16. Summary of Effects to Cultural Resources at Risk: Alternative 7.....................................................568

Table 3.05-17. Comparison of Effects to Cultural Resources ...................................................................................570

Table 3.06-1. Acres of Vegetation Type on the TNF ................................................................................................574

Table 3.06-2. Number of Sensitive Species Occurrences Known to Occur on TNF System Lands..........................575

Table 3.06-3. Some of the Weeds known to occur on TNF System Lands...............................................................589

Table 3.06-4. Unauthorized Routes and Closed NFTS roads still receiving some motorized use with Sensitive

and Watchlist Plants/Plant Communities ....................................................................................................590

Table 3.06-5. Number of perennial and intermittent water crossings by alternative .................................................605

Table 3.06-6. Miles of proposed additions to the NFS located within 100 feet of riparian vegetation by

alternative....................................................................................................................................................605

Table 3.06-7. Proposed additions to the NFTS that pass through sensitive/watchlist occurrences and/or

watchlist aquatic/riparian plant communities by alternative .......................................................................606

Table 3.06-8. Miles of road/trail/area within serpentine plant communities by alternative.......................................616

Table 3.06-9. Miles of road/trail/area within older forest plant communities by alternative.....................................622

Table 3.06-10. Miles of road/trail/area within oak woodland plant communities by alternative...............................628

Table 3.06-11. Miles of road/trail/area within forest edge/opening plant communities by alternative .....................631

Table 3.06-12. Miles of proposed additions to the NFTS within high elevation opening/rocky areas by

alternative....................................................................................................................................................638

Table 3.06-13. Weed occurrences along proposed additions to the NFTS................................................................642

Table 3.06-14. Total miles of roads/trails/areas in inventoried roadless areas by alternative....................................649

Table 3.06-15. Comparison of Effects to Plants/Plant Communities ........................................................................654
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xxiv – Tahoe National Forest

Table 3.07-1. Amendments to the Tahoe National Forest Land Resource Management Plan in regard to ROS,

and Season of Use by alternative.................................................................................................................659

Table 3.07-2. ROS acres in each class for all alternatives.........................................................................................659

Table 3.07-3. Acreage within 1⁄2 mile of routes proposed for public use under each alternative as a

measurement indicator of acreage affected by motorized use where quiet recreation and nonmotorized activities may have potential use conflicts with motorized vehicles..........................................661

Table 3.07-4. NFTS road mileage open to the public by alternative (class of vehicle and season of use) ................662

Table 3.07-5. NFTS road mileage open to the public forestwide – total mileage of proposed mixed use by

alternative (class of vehicle and season of use). Mixed use would occur on existing NFTS roads.

Existing NFTS roads where mixed use is proposed or currently allowed would be available for use

by all vehicle classes listed in Table 3.07-4 ................................................................................................663

Table 3.07-6. Miles of NFTS routes with a proposed change in the season of use by alternative.............................663

Table 3.07-7. NFTS Trail mileages open to the public forestwide by alternative .....................................................664

Table 3.07-8. NFTS Trail mileages open for public use forestwide by alternative by degree of difficulty...............665

Table 3.07-9. “Open Area” acreage forestwide by alternative by vehicle class........................................................665

Table 3.07-10. Number of dispersed recreation sites accessed by routes proposed for addition to the NFTS, or

ML 1 roads reopened to motorized use under each alternative ...................................................................666

Table 3.07-11. Number of miles of routes proposed for addition to the NFTS under each alternative within 1⁄2

mile of neighboring private and federal lands (includes roads and trails)...................................................667

Table 3.07-12. Tahoe NF visitor activity participation as reported in NVUM result (2005).....................................669

Table 3.07-13. Approximate Tahoe NF visitors by type of main activity as reported in NVUM results (2005).......670

Table 3.07-14. Reasonably foreseeable projects with possible cumulative effects to recreation ..............................696

Table 3.07-15. Motorized Recreation Opportunities Cumulative Effects – Recreation Measurement Indicator 3 ...698

Table 3.07-16. Forest acres and mileage of inventoried unauthorized routes and closed NFTS roads still

receiving motorized use by retention and partial retention visual quality objectives (National Forest

System lands only) ......................................................................................................................................711

Table 3.07-17. Miles of route added to the NFTS in retention and partial retention VQO .......................................712

Table 3.07-18. Non-motorized Recreation Summary................................................................................................719

Table 3.07-19. Motorized Recreation Summary........................................................................................................719

Table 3.07-20 Visual Resources Summary................................................................................................................719

Table 3.08-1. Average Costs for Annual Road and Trail Maintenance in the Tahoe National Forest.......................723

Table 3.08-2. Tahoe National Forest’s Past Years’ Road Budgets (in nominal dollars) ...........................................724

Table 3.08-3. Summary comparison of alternatives with respect to public safety ....................................................728

Table 3.08-4. Summary comparison of alternatives with respect to affordability of annual maintenance, 

implementation, and mitigations.................................................................................................................730

Table 3.08-5. Comparison of Effects to Transportation ............................................................................................732

Table 3.09-1. Inventoried Roadless Areas – Tahoe National Forest .........................................................................737

Table 3.09-2. Roads and Trails in the Bald Mountain Inventoried Roadless Area....................................................738

Table 3.09-3. Roads and Trails in the Castle Peak Inventoried Roadless Area .........................................................739

Table 3.09-4. Roads and Trails in the Duncan Canyon Inventoried Roadless Area..................................................740

Table 3.09-5. Roads and Trails in the East Yuba Inventoried Roadless Area ...........................................................740

Table 3.09-6. Roads and Trails in the Granite Chief Inventoried Roadless Area......................................................741

Table 3.09-7. Roads and Trails in the Grouse Lakes Inventoried Roadless Area......................................................742

Table 3.09-8. Roads and Trails in the Lakes Basin Inventoried Roadless Area ........................................................742

Table 3.09-9. Roads and Trails in the Middle Yuba Inventoried Roadless Area.......................................................743
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Tahoe National Forest – xxv

Table 3.09-10. Roads and Trails in the North Fork American River Inventoried Roadless Area .............................744

Table 3.09-11. Roads and Trails in the North Fork of the Middle Fork American River IRA..................................744

Table 3.09-12. Roads and Trails in the West Yuba Inventoried Roadless Area........................................................745

Table 3.09-13. Total Roads/Trails/Areas in Inventoried Roadless Areas by Alternative ..........................................749

Table 3.09-14. Miles of Roads/Trails/Areas in East Yuba Inventoried Roadless Area by Alternative .....................755

Table 3.09-15. Miles of Roads/Trails/Areas in Grouse lakes Inventoried Roadless Area by Alternative .................758

Table 3.09-16. Miles of Roads/Trails/Areas in West Yuba Inventoried Roadless Area by Alternative....................764

Table 3.09-17. Roads and Trails in Citizen Inventoried Roadless Areas (total TNF acreage outside IRAs) ............765

Table 3.09-18. Total Roads/Trails/Areas in Citizen Inventoried Roadless Areas by Alternative .............................769

Table 3.09-19 Summary Table – Special Areas – Tahoe NF ....................................................................................778

Table 3.10-1. Routes Potentially Affecting Private Land under Consideration for Addition to the NFTS ...............780

Table 3.10-2. Motorized Roads and Trails within Urban/Rural/Wildland Interface .................................................782

Table 3.10-3. Additions to the NFTS and Reopening of Maintenance Level 1 roads on the other side of

Private Land by Alternative ........................................................................................................................784

Table 3.10-4. Miles of roads and trails for each alternative within 1⁄4 mile of private land by class of vehicle

and season of use.........................................................................................................................................794

Table 3.10-5. Comparison of Effects to Adjacent Ownerships .................................................................................795

Table 3.11-1. Historic Population of Counties in the TNF Region (thousands of people)........................................797

Table 3.11-2. Percent of TNF Region county populations by ethnicity, 1998 ..........................................................798

Table 3.11-3. Projected populations of the TNF Region counties by ethnicity, 2040 ...............................................799

Table 3.11-4. Percent of Population of TNF Region counties by age group, 1998 ...................................................799

Table 3.11-5. Projected percent of population of TNF Region Counties by age group, 2040...................................799

Table 3.11-6. Inflation-adjusted per capita incomes - Residents of TNF Region counties, 1972-1997 ....................800

Table 3.11-7. Patterns and Trends in Seasonality of Employment in TNF Region Counties, 1989-1998.................801

Table 3.11-8. Activity Participation on Tahoe National Forest (NVUM FY2005 data)............................................802

Table 3.11-8a. Number of Party Trips by Activity....................................................................................................804

Table 3.11-9. Expenditures ($ per visit) by Activity .................................................................................................805

Table 3.11-10. Employment and Labor Income Response Coefficients by Activity Type .......................................808

Table 3.11-11. Employment and Labor Income Effects by Activity Type................................................................810

Table 3.11-12. Percent of Total Employment and Labor Income Effects by Activity Type .....................................811

Table 3.11-13a. Total Employment and Labor Income Effects.................................................................................812

Table 3.11-13b. Percent of Total Area Employment and Total Area Labor Income Effects.....................................813

Table 3.11-14. Community clusters used to analyze economic and social impacts on communities........................814

Table 3.11-15. Percentages of residents by race and Hispanic cultural heritage for Tahoe National Forest

community clusters, 1990............................................................................................................................815

Table 3.11-16. Per capita incomes of residents in Tahoe National Forest community clusters by ethnicity and 

cultural heritage, 1989.................................................................................................................................816

Table 3.11-17. Community clusters of concern based on income by ethnic or cultural heritage group, sources

of employment, and percent unemployment ...............................................................................................817

Table 3.11-18. All people and all children living in poverty in the TNF Region counties, 1996..............................817

Table 3.11-19. Enrollment, poverty status, pupil-teacher ratios, and expenditures per pupil for schools

attended by pupils living in Sierra Nevada Region .....................................................................................818

Table 3.11-20. Changes in Forest Service payments (in 1995 dollars) to Sierra Nevada Region counties,

1992 and 1997 .............................................................................................................................................818
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xxvi – Tahoe National Forest

Table 3.11-21. Combined Average Scholastic Aptitude Test (SAT) scores for High Schools Attended by

Sierra Nevada Region Students...................................................................................................................819

Table 3.11-22. Miles of roads available for fuel wood gathering opportunities by time of year...............................821

Table 3.11-23. Summary of Forest Service Civil Rights Impact Analysis and environmental justice by

community clusters in the Sierra Nevada Region........................................................................................821

Table 3.11-24. Summary of impacts to social groups by alternative.........................................................................823

Table 3.11-25. American Indian Tribes Communications.........................................................................................826

Table 3.11-26. Comparison of Effects to the Social Economic Environment ...........................................................828

Table 4-1. American Indian Tribes summary of communications ............................................................................832
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Tahoe National Forest – xxvii

List of Figures

Figure 1-1. Vicinity Map ...............................................................................................................................................6

Figure 3.01-1. California Air Basins/Counties and Air Pollution Control Districts....................................................60

Figure 3.01-2. Areas “Most Likely” to Contain Naturally Occurring Asbestos..........................................................66

Figure 3.02-1. Total Route Density and Forest Service Route Density for Alternatives 1, 2 and 5 ............................82

Figure 3.02-2. EMDS Landscape erosion values by HUC6. .....................................................................................128

Figure 3.02-3. Native surface road and motorized trail crossing density in the Truckee River Basin (within the

TNF boundary) by Alternative ....................................................................................................................135

Figure 3.02-4. Native surface road and motorized trail density in RCAs in the Truckee River Basin (within the

TNF boundary) by Alternative ....................................................................................................................136

Figure 3.02-5. Native surface roads and motorized trails by alternative and density class .......................................140

Figure 3.03-1. Blue Canyon Deer Herd Key Winter Range – Existing Motorized Routes .......................................211

Figure 3.03-2. Blue Canyon Deer Herd - LMP Amendment Proposed Change in Season of Use within the

Humbug-Sailor Management Area..............................................................................................................213

Figure 3.03-3. Blue Canyon Deer Herd Population Trend within the Deer Hunt Zone D-4 .....................................215

Figure 3.03-4. Cumulative Motorized Miles in Spotted Owl PACs..........................................................................295

Figure 3.03-5. Cumulative Motorized Miles in Spotted Owl HRCAs.......................................................................297

Figure 3.03-6. Cumulative Route Miles in Goshawk PACs......................................................................................324

Figure 3.03-7. Cumulative Miles within 0.25 miles of Goshawk Activity Centers (Nest Site/Nest Stand) ..............325

Figure 3.03-8. Cumulative Effects of All Routes within a 400-meter Zone of Influence within Tahoe NF

Northern Goshawk PACs............................................................................................................................328

Figure 3.03-9. Number of HUC7 Watersheds with Occupied LCT streams by Route Density Categories of

Lowest, Lower, Higher, and Highest...........................................................................................................433

Figure 3.03-10. Number of HUC7 Watersheds with occupied LCT streams by Motorized Crossing Density 

Categories....................................................................................................................................................434

Figure 3.03-11. Proportion of HUC7 Watersheds with Suitable Lahontan Lake Tui Chub Habitat by

Motorized RCA Route Density Categories.................................................................................................445

Figure 3.03-12. Number of HUC7 Watersheds with suitable Lahontan Lake Tui Chub Habitat by Motorized

Stream Crossing Density Categories...........................................................................................................446

Figure 3.03-13. Number of HUC7 Watersheds with Foothill Yellow-legged Frogs by Route Density Category

for Motorized Route Density (Native Surfaced) with Riparian Conservation Areas ..................................466

Figure 3.03-14. Number of HUC7 Watersheds with Foothill Yellow-legged Frogs by Route Density Category

for Motorized Stream Crossing Density (Native Surfaced) with Riparian Conservation Areas .................468

Figure 3.03-15. Number of 7th Field Watersheds within RCA Route Density Categories with Known Mountain 

Yellow-legged Frogs Locations ..................................................................................................................483

Figure 3.03-16. Number of 7th Field Watersheds by Native Surfaced, Motorized Crossing Density Category

for Known Mountain Yellow-legged Frog Locations.................................................................................484

Figure 3.03-17. Number of Northwestern Pond Turtle 7th Field Watersheds by Motorized Native Surface

RCA Route Density Category .....................................................................................................................497

Figure 3.03-18. Northwestern Pond Turtle 7th Field Watersheds by Motorized Crossing........................................499

Figure 3.07-1. Tahoe National Forest Visual Quality Objectives..............................................................................706

Figure 3.08-1. Congressional Budget Office’s Projected Growth of the U.S. Economy and Federal Spending

for Major Mandatory Programs, 2007-2017................................................................................................724
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

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xxviii – Tahoe National Forest
Chapter 1 

Purpose and Need 

Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Tahoe National Forest – 1

Chapter 1: Purpose and Need

Document Structure _____________________________________

The Forest Service has prepared this Environmental Impact Statement in compliance with the National 

Environmental Policy Act (NEPA) and other relevant Federal and State laws and regulations. This 

Environmental Impact Statement discloses the direct, indirect, and cumulative environmental impacts that 

would result from the Proposed Action and alternatives. The document is organized into four chapters and 

the Appendices: 

1. Chapter 1: Purpose and Need. This chapter briefly describes the Proposed Action, the need for 

that action, and other purposes to be achieved by the proposal. This section also details how the 

Forest Service informed the public of the Proposed Action and how the public responded. 

2. Chapter 2: The Alternatives. This chapter provides a detailed description of the agency’s 

Proposed Action as well as alternative actions that were developed in response to comments 

raised by the public during scoping. The end of the chapter includes summary tables comparing 

the Proposed Action and alternatives with respect to their environmental effects.

3. Chapter 3: Affected Environment and Environmental Consequences. This chapter describes 

the environmental impacts of the Proposed Action and alternatives. 

4. Chapter 4: Consultation and Coordination. This chapter provides a list of preparers and 

agencies consulted during the development of the environmental impact statement. 

5. Appendices: The appendices provide more detailed information to support the analyses 

presented in the environmental impact statement.

Additional documentation, including more detailed analyses of project area resources, may be found 

in the project planning record located at the Tahoe National Forest Supervisors Office, 631 Coyote Street, 

Nevada City California 95959.

Background ____________________________________________

Over the past few decades, the availability and capability of motorized vehicles, particularly off-highway 

vehicles (OHVs) and sport utility vehicles (SUVs) has increased tremendously. Nationally, the number of 

OHV users has climbed sevenfold in the past 30 years, from approximately 5 million in 1972 to 36 

million in 2000. California is experiencing the highest level of OHV use of any state in the Nation. There 

were 786,914 ATVs and OHV motorcycles registered in California in 2004, up 330 percent since 1980. 

Annual sales of ATVs and OHV motorcycles in California were the highest in the U.S. for the last 5 years. 

Four-wheel drive vehicle sales in California also increased 1,500 percent to 3,046,866 from 1989 to 2002.

Unmanaged OHV use on National Forest System lands has resulted in unplanned roads and trails, 

erosion, watershed and habitat degradation, and impacts to cultural resource sites. Compaction and 

erosion are the primary effects of OHV use on soils. Riparian areas and aquatic dependent species are 

particularly vulnerable to adverse impacts from OHV use. Unmanaged recreation, including impacts from 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 1: Purpose and Need

2 – Tahoe National Forest

OHVs, is one of “Four Key Threats Facing the Nation’s Forests and Grasslands.” (USDA Forest Service, 

June 2004).

On August 11, 2003, the Pacific Southwest Region of the Forest Service entered into a Memorandum 

of Intent (MOI) with the California Off-Highway Motor Vehicle Recreation Commission and the OffHighway Motor Vehicle Recreation Division of the California Department of Parks and Recreation. The

MOI set in motion a region-wide effort to “designate OHV roads, trails, and any specifically defined open 

areas for motorized wheeled vehicles on maps of the 19 National Forests in California by 2007.”

On November 9, 2005, the Forest Service published final travel management regulations in the 

Federal Register (FR Vol. 70, No. 216-Nov. 9, 2005, pp 68264-68291). This final Travel Management 

Rule requires designation of those roads, trails, and areas that are open to motor vehicle use on National 

Forest System lands. Roads and trails designated for motorized use must be included in the National 

Forest Transportation System (NFTS). Designations are made by class of vehicle and, where appropriate, 

by time of year. The final rule prohibits the use of motor vehicles off designated roads, trails, and areas, as 

well as use of motor vehicles on roads and trails and in areas that is not consistent with the designations.

On some National Forest System (NFS) lands, long managed as open to cross country motor vehicle

travel, repeated use has resulted in unplanned, unauthorized roads and trails. These routes generally 

developed without environmental analysis or public involvement, and do not have the same status as NFS 

roads and NFS trails included in the NFTS. Nevertheless, some unauthorized routes are well-sited, 

provide excellent opportunities for outdoor recreation by motorized and non-motorized users, and would 

enhance the NFTS. Other unauthorized routes are poorly located and cause unacceptable impacts. Only 

NFS roads and NFS trails can be designated for motor vehicle use. In order for an unauthorized route to 

be designated, it must first be added to the Forest transportation system.

In 2005 the TNF completed an inventory of unauthorized routes on NFS lands and identified 897 

miles of unauthorized routes and an additional 513.7 miles of Maintenance Level 1 roads still receiving 

motorized use by the public. The result was a total of 1,410.7 miles having unauthorized motorized use by 

the public. Between the DEIS and Supplementary DEIS corrections were made to the NFTS (see 

discussion below on Corrections to the NFTS) and these figures were revised to 868.7 miles of 

unauthorized routes and 829.6 miles of Maintenance Level 1 roads receiving motorized use for a total 

1,698.3 miles having unauthorized motorized use by the public.

TNF used an interdisciplinary process to conduct travel analysis that included working with the 

public to identify proposals for changes to the existing TNF transportation system. Roads and trails that 

are currently part of the TNF transportation system and open to motor vehicle travel would remain

designated for such use, except as described below under the Proposed Action. This proposal makes 

needed changes (seasonal restrictions, vehicle class restrictions, etc.) to the Tahoe National Forest NFTS 

roads and NFTS trails on NFS lands in accordance with the Travel Management Rule (36 CFR Part 212, 

Subpart B).

In accordance with 36 CFR Part 212, Subpart B of the Travel Management Rule (36 CFR §212.56), 

following a decision on this proposal, the TNF will publish a motor vehicle use map (MVUM) identifying 

all TNF NFTS roads, trails, and areas that are designated for motor vehicle use. The MVUM shall specify 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 1: Purpose and Need

Tahoe National Forest – 3

the classes of vehicles and, if appropriate, the time of year for which motor vehicle use is designated. 

Upon publication of the MVUM, it is prohibited to possess or operate a motor vehicle on NFS lands other 

than in accordance with those designations. These maps will be made available to the public on the 

internet and at the headquarters of the corresponding administrative unit and Ranger Districts of the 

National Forest System. The unauthorized routes (roads and trails) not included in this proposal are not 

precluded from future consideration for either removal from the landscape and restoration to the natural 

condition or addition to the NFTS and inclusion on an MVUM. Future decisions associated with changes 

to the NFTS and MVUM would require additional environmental analysis, public involvement, and 

documentation.

Travel Management –Tahoe National Forest Transportation System

The TNF currently manages and maintains approximately 2,067.6 miles of NFTS roads, 328.2 miles of 

NFS motorized trails, and 1 established “Open Area.” This number has changed since the DEIS as 

explained below under Corrections to the NFTS Data in the DEIS. The Tahoe National Forest 

Transportation System (NFTS) was developed over many decades to meet a variety of needs, including 

timber management, fuel treatment, access to private inholdings, fire control, utility management, specialuses management, and recreation. Other roads were acquired with past land exchanges or acquisitions. 

Harvesting of special forest products such as greenery, firewood, mushrooms, and plants are among the 

many opportunities afforded by the NFTS. Management of the transportation system on the Tahoe 

National Forest is a dynamic process. Implementation of this proposal and the subsequent designation of 

motor vehicle routes through publication of the MVUM is just one project, among many, that affects the 

Forest’s transportation system. Over the last decade, the Forest has moved away from a commodity 

(timber) focus to one of ecosystem health and integrated vegetation management. In response to this shift, 

the Forest Supervisor initiated the following actions that reduced both road maintenance needs and 

deferred maintenance needs:

Previous administrative decisions have reduced the number of miles of NFTS roads available for 

motorized use and restricted the season of use. These previous administrative decisions have 

resulted in 395 miles being closed to wheeled public motorized access, 672 miles being seasonally 

closed, and 125 miles decommissioned.

The amount of NFTS trails available for motorized use has also been reduced by previous 

administrative decisions. More than 433 miles of existing system trails have been closed to all 

motorized use and more than 63 miles seasonally closed.

Large geographic areas of the Forest in previous administrative decisions have been determined to be 

unsuitable for motorized use. 87,000 acres have been designated as unsuitable for any motorized 

use and 160,000 acres have been designated as suitable for seasonal use only.

Implementation of this proposal and the subsequent designation of motor vehicle routes through 

publication of the MVUM are only one step in the overall management of the TNF NFTS. Project-level 

planning efforts include reducing adverse environmental impacts associated with unauthorized motorized 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 1: Purpose and Need

4 – Tahoe National Forest

routes. The Forest’s road and trail maintenance program addresses impacts associated with the current 

NFTS.

The NFTS is managed and maintained to various road standards, depending on management 

objectives. The roads range from paved to roughly graded, high-clearance roads, depending on the type of 

access necessary. In some cases, where public and administrative access is not needed for extended 

periods of time, roads are “stored” for future management use. The entire NFTS (“stored”, administrativeuse and public-use roads) is displayed on the Forest Transportation Atlas. The Forest Transportation Atlas 

consists of the maps, inventories, and plans for Forest transportation facilities and associated information 

available as of January 12, 2001 (Forest Service Manual 7711.2). Details concerning the management of 

individual roads and trails are maintained in the Forest infrastructure database (INFRA).

In 2002, based on national direction the TNF populated the INFRA database by examining previous 

records (maintenance plans, maintenance expenditures, existing road and trail atlases, Forest maps, etc.) 

to capture the entire NFTS, transfer the necessary information into INFRA, and verify the Forest 

Transportation Atlas. Roads or trails that had no record of being mapped or maintained for a specific use 

were not included in the NFTS.

Since then, adjustments to the Transportation Atlas and INFRA database have been made to correct 

errors and account for NFTS roads that were either newly constructed or overlooked in the 2002 effort. 

The current Forest Transportation Atlas identifies the existing NFTS and the management objectives for 

each transportation facility. These objectives have changed since the DEIS as explained below under 

Corrections to the NFTS Data in the DEIS. Decisions regarding changes to the NFTS (new road 

construction, addition of unauthorized routes as NFTS facilities, realignment, decommissioning, etc.) are 

subject to the National Environmental Policy Act (NEPA) and require public involvement and disclosure. 

The NFTS is continually changing, depending on resource needs and management concerns.

Corrections to the NFTS Data in the DEIS –

Preparation of a Supplemental DEIS

The TNF undertook a comprehensive review of its existing NFTS after the release of the Draft Travel 

Management EIS (DEIS). This review was done to respond to the following two concerns expressed by 

the public during the comment period on the DEIS.

• Status of NFTS: Letters from both the environmental and OHV communities questioned the 

inclusion or exclusion of roads/trails from the existing NFTS. The environmental community felt 

many of the NFTS roads/trails should be considered “unauthorized” while the OHV community 

felt that many of the “unauthorized” routes were actually part of the previously approved NFTS.

• Valid Rights-of-Way (ROW): Letters from private landowners, including Pacific Gas and 

Electric Company, Sierra Pacific Industries, and Nevada Irrigation District, stated that several of 

the NFTS roads/trails were shown in error on their land since the Forest Service did not have a 

valid existing ROW. They requested these roads/trails not be shown on their land in the Final EIS.

The Forest Service validated the status of every NFTS road and trail on the Forest by utilizing the 

following information:
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 1: Purpose and Need

Tahoe National Forest – 5

• INFRA Database: Jurisdiction discrepancies between INFRA and the Project GIS database were 

corrected.

• Previous NEPA Decisions: Available NEPA decisions regarding road and trail management from 

last fifteen years were reviewed.

• Rights-of-Way Atlas: The rights-of-way (ROW) status of all NFTS roads and trails were 

validated based on the Forest ROW Atlas.

Based on this review, the following corrections were made to the NFTS motorized recreation 

opportunities. These corrections were incorporated into all of the alternatives. Refer to Tables 1-1 and 1-2.

Table 1-1. Summary of corrections to the motorized recreation opportunities

Category of 

correction

Reason for correction Miles

Additional NFTS 

motorized 

recreation 

opportunities

State or County roads determined to be part of the NFTS 32.2

Previous NEPA decision added road/trail to the NFTS 69.4

Previous NEPA decision converted non-motorized trail to a motorized road or 

trail

2.7

Subtotal 104.3

Changes in type of 

NFTS motorized 

recreation 

opportunities

Previous NEPA decision changed the class of vehicle allowed 76.8

Previous NEPA decision changed season of use on NFTS road/trail 579.6

Previous NEPA decision changed both season of use and class of vehicle 

allowed on NFTS road/trail

33.5

Subtotal 689.9

Reductions in NFTS 

motorized 

recreation 

opportunities

Previous NEPA decision scheduled NFTS road/trail for decommissioning 20.7

NFTS roads/trails on private land determined to not have a valid right of way 124.5

NFTS roads determined to be under State or County Jurisdiction 8.8

Previous NEPA decision converted motorized road/trail to a non-motorized trail 5.2

Previous NEPA Decision closed the road/trail 349.7

Subtotal 508.9

Table 1-2. Summary of NFTS Mileage Before and After Corrections

Class of Vehicle DEIS Mileage Supplemental 

DEIS Mileage

Change

Roads open to highway legal vehicles only 629.3 616.7 -12.6

Roads open to all vehicles 1,845.2 1,450.9 -394.3

Trails open to high clearance trail vehicles only 161.5 133.8 -27.7

Trails open to ATV’s and motorcycles only 16.8 25.5 +8.7

Trails open to motorcycles only 147.6 168.8 +21.2

Total 2,800.4 2,395.7 -404.7

The Forest Supervisor reviewed this information and based on the interdisciplinary team’s 

recommendation, determined the preparation of a Supplemental DEIS was warranted so that the public 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 1: Purpose and Need

6 – Tahoe National Forest

has an opportunity to review the proposed action and alternatives in light of the corrections that have been 

made since the DEIS was circulated.

Project Location ________________________________________

This proposal includes the entire Tahoe National Forest. The Tahoe National Forest straddles the crest of 

the Sierra Nevada Mountains in northern California, and encompasses a vast territory, from the foothills

on the western slope to the eastern slope of the Sierras (Figure 1-1). The Forest is bordered on the north 

by the Plumas National Forest, on the south by the Eldorado National Forest, and on the east by the 

Humboldt-Toiyabe National Forest and Lake Tahoe Basin Management Unit. On the Forest’s western 

border are the foothills above the Sacramento Valley.

Figure 1-1. Vicinity Map

Purpose and Need_______________________________________

The following needs have been identified for this proposal:

There is a need for regulation of unmanaged cross country motor vehicle travel by the public.

The proliferation of unplanned, unauthorized, non-sustainable roads, trails, and areas created by 

cross country travel adversely impacts the environment. The 2005 Travel Management Rule, 36 

CFR Section 212, Subpart B, provides for a system of NFS roads, NFS trails, and areas on NFS

lands that are designated for motor vehicle use. After roads, trails, and areas are designated, motor 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 1: Purpose and Need

Tahoe National Forest – 7

vehicle use off designated roads and trails and outside designated areas is prohibited by 36 CFR 

261.13. 36 CFR Part 212, Subpart B is intended to prevent resource damage caused by unmanaged 

motor vehicle use by the public. In accordance with national direction, implementation of 36 CFR 

Part 212, Subpart B of the travel management rule for the Tahoe National Forest is scheduled for 

completion in January 2010.

There is a need for limited changes to the TNF transportation system to:

 Provide motorized access to existing dispersed recreation opportunities (camping, hunting, 

fishing, hiking, horseback riding, etc.). There is a need to maintain motor vehicle access to 

dispersed recreation activities that are known to have been historically accessed by motor 

vehicles. A substantial portion of known dispersed recreation activities (camping, fishing, 

hiking, horseback riding, hunting, etc.) are not located directly adjacent to an existing NFTS 

road or motorized trail. Some dispersed recreation activities depend on foot or horseback 

access, and some depend on motor vehicle access. These dispersed non-motorized activities 

depend on motor vehicle access using short spurs created and maintained primarily by the 

passage of motor vehicles. Many such unauthorized ‘user-created’ routes are not currently part 

of the NFTS. Without adding them to the NFTS, the regulatory changes noted above would 

make continued use of such routes illegal through the prohibition of cross country travel, and 

would preclude access to many dispersed recreation activities.

 Provide a diversity of motorized recreation opportunities (4X4 vehicles, motorcycles, ATVs, 

SUVs, passenger vehicles, etc.). It is Forest Service policy to provide a diversity of road and 

trail opportunities for experiencing a variety of environments and modes of travel consistent 

with the National Forest recreation role and land capability (FSM 2353.03(2)). Implementation 

of 36 CFR Part 212, Subpart B of the Travel Management Rule will reduce acres and miles of 

motorized recreation opportunities relative to current levels. As a result, there is a need to 

consider limited changes to the NFTS.

In making any limited changes to the NFTS, the TNF will be considering criteria contained in 36 

CFR Part 212, Subpart B of the Travel Management Rule, which include the following: 

• Impacts to natural and cultural resources.

• Public safety.

• Access to public and private lands.

• Availability of resources for maintenance and administration.

• The need for maintenance and administration of roads trails and areas that would arise if the uses 

under consideration are designated. 

• Minimizing damage to soil, watershed, vegetation, and other forest resources.

• Minimizing harassment of wildlife and significant disruption of wildlife habitat.

• Minimizing conflicts between motor vehicles and existing or proposed recreational uses of NFS 

lands or neighboring Federal lands.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 1: Purpose and Need

8 – Tahoe National Forest

• Minimizing conflicts among different classes of motor vehicle uses of NFS lands or neighboring 

Federal lands.

• Compatibility of motor vehicle use with existing conditions in populated areas, taking into 

account sound, emissions, and other factors.

When making any limited changes to NTFS Roads, the TNF will also consider the following:

• Speed, volume, composition and distribution of traffic on roads.

• Compatibility of vehicle class with road geometry and road surfacing

• Maintaining valid existing rights-of-use and access (rights-of-way)

Table 1-3 provides a summary of the Purpose and Need details related to the five components of the 

Proposed Action.

Table 1-3. Relation of Purpose and Need to Proposed Actions

What Where Why How

1. Prohibition of Cross Country Travel

Travel and Parking Forestwide outside of 

Wilderness 

Implement 36 CFR 212, Subpart B 

limiting motorized use to the NFTS 

system; protect resources by 

preventing route proliferation; 

provide parking for dispersed 

recreation 

Prohibit cross country 

travel; parking allowed 

one vehicle length off of 

NFTS routes 

2. Additions to the NFTS

Add existing 

unauthorized routes to 

the NFTS 

Specific routes shown in 

Appendix A and on 

alternative maps

Provide a variety of motorized trail 

opportunities; enhance loop 

opportunities; access destinations; 

reduce conflicts between different 

uses 

Add unauthorized routes 

to the trail system; show 

on MVUM pending 

completion of mitigations 

3. Establishment of Motorized “Open Areas”:

Establish “Open Areas” Specific “Open Areas” 

shown in Appendix A 

and on alternative maps

Provide a diversity of motorized 

recreation opportunities; Provide 

motorized access to existing 

dispersed recreation opportunities.

Establish “Open Areas”; 

show on MVUM pending 

completion of mitigations 

4a. Change Vehicle Classes through Mixed Use

(Roads maintained for passenger cars available for use by non-highway legal vehicles):

Change NFTS roads 

from Highway Legal 

Only to All Vehicles 

Specific roads shown in 

Appendix J and on 

alternative maps

Provide a variety of motorized 

mixed use opportunities; enhance 

loop opportunities by connecting 

trails

Show on MVUM as open 

to all vehicles pending 

completion of mixed use 

mitigations 

4b. Change Vehicle Classes through Maintenance Levels

(Roads presently maintained for passenger cars to be maintained in the future for high clearance vehicles):

Change NFTS roads 

from Highway Legal 

Only to All Vehicles 

Specific routes shown in 

Appendix J and on 

alternative maps 

Provide a variety of motorized 

mixed use opportunities; enhance 

loop opportunities by connecting 

trails; reduce maintenance needs 

Show on MVUM as open 

to all vehicles pending 

completion of mixed use 

mitigations 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 1: Purpose and Need

Tahoe National Forest – 9

What Where Why How

4c. Changes in Seasonal Restrictions:

Wet Weather Closures Forestwide outside of 

Wilderness on all native 

surface roads and 

motorized trails

Protect resources including road 

and trail surfaces during wet 

periods

During the wet season of 

use all native surfaced 

routes are closed; show 

on MVUM 

4d. Reopening Maintenance Level 1 Roads:

Change NFTS roads 

from Closed to Open 

Specific routes shown in 

Appendix A and on 

alternative maps 

Existing NFTS roads; access 

destinations; enhance loop 

opportunities by connecting trails 

Open any existing gates 

or remove barriers as 

needed; show on MVUM 

5. Amendments to the Forest Plan:

Non-significant 

amendments 

Specific routes in 

Management Area 84; 

shown in Appendix A 

and on alternative maps

Remove deer winter range 

seasonal restrictions to improve 

motorized recreation opportunities 

Forest Plan Amendment 

for native surface roads 

and trails in Management 

Area 84; show on MVUM

Proposed Action as Described in the Notice of Intent _________ 

1. Prohibition of Cross Country Travel: Public wheeled motor vehicle travel off designated 

NFTS roads, NFTS trails, and outside designated motorized use areas would be prohibited, 

except as allowed by permit or other authorization.

2. Additions to the NFTS:

a. No unauthorized routes would be added as roads to the NFTS.

b. 36.7 miles (36 routes) of unauthorized routes would be added as motorized trails to the 

NFTS.

3. Establishment of Motorized “Open Areas”: No additional motorized “Open Areas” would be 

established.

4. Changes to the NFTS: 

a. Change Vehicle Classes through Mixed Use: No changes would be made to allow licensed 

operators of non-highway legal vehicles to operate on NFTS roads where such use is 

currently prohibited through approval of mixed use.

b. Change Vehicle Classes through Maintenance Levels: Change vehicle class on 3.4 miles to 

allow operators of non-highway legal vehicles to operate on NFTS roads where such use is 

currently prohibited through the conversion of ML 3 roads (maintained for passenger cars) to 

ML 2 (maintained for high clearance vehicles).

c. Changes in Seasonal Restrictions: No changes in seasonal restrictions would be made.

d. Reopening Maintenance Level 1 Roads: Two Maintenance Level 1 roads (1.1 miles) would 

be reopened to motorized use.

5. Amendments to the Forest Plan: No amendments would be made to the Forest Plan.

Appendix A (Site Specific Road, Trail and Open Area Information) shows the specified vehicle class, 

season of use and any required mitigations associated with any facility added to the NFTS.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 1: Purpose and Need

10 – Tahoe National Forest

Including the additions and changes described above, the Proposed Action would result in a system of 

2,068.5 miles of NFTS roads and 365.0 miles of NFTS motorized trails open to public motorized use. A 

more detailed description of the Proposed Action can be found in Chapter 2 (The Alternatives). Maps of 

the Proposed Action are available on compact disc.

Principle Laws and Regulations that influence the scope of this EIS __

The National Environmental Policy Act of 1969 (NEPA) requires that all major federal actions significantly 

affecting the human environment be analyzed to determine the magnitude and intensity of those impacts 

and that the results be shared with the public and the public be given opportunity to comment. The 

regulations implementing NEPA further require that, to the fullest extent possible, agencies shall prepare 

environmental impact statements concurrently with, and integrated with, environmental analyses and related 

surveys and studies required by the Endangered Species Act of 1973, the National Historic Preservation Act 

of 1966, and other environmental review laws and executive orders. Principle among these are the Multiple 

Use and Sustained Yield Act of 1960, the National Forest Management Act of 1976 as expressed through 

the Tahoe National Forest Land and Resource Management Plan (as amended, 2007), the Clean Air Act of 

1955, the Clean Water Act of 1948, and the Forest and Rangeland Renewable Resources Planning Act of 

1974. In addition, the TNF Travel Management EIS is designed specifically to implement the requirements 

of 36 CFR 212, Subpart B, of the November 5, 2005 Rule for Travel Management (36 CFR 212.50-57). 

Other laws, regulation, and guidance specific to individual resources are found within the respective 

resource section in Chapter 3 (Affected Environment and Environmental Consequences) of this document.

Decision Framework ____________________________________

The Forest Supervisor for the TNF will be the responsible official. The responsible official will decide 

whether to adopt and implement the Proposed Action, an alternative to the Proposed Action, or take no 

action at this time. This proposal does not revisit previous administrative decisions that resulted in the 

current NFTS. This proposal is focused on implementing 36 CFR 212, Subpart B of the Travel 

Management Rule. Previous administrative decisions concerning road construction, road reconstruction, 

trail construction, and land suitability for motorized use on the existing NFTS are outside of the scope of 

this analysis.

Public Participation______________________________________

The Interdisciplinary Team relied on public involvement to ensure that a full range of alternatives, 

representing a broad array of perspectives, would be analyzed in this DEIS. Public involvement occurred 

during three key periods: first, during the public collaboration process that began in 2006; second, during 

the 30-day public scoping period for the Notice of Intent (NOI); and third, during meetings with public 

groups to refine alternatives they proposed during scoping.

During the summer 2006, a variety of trail users, including motorized and non-motorized users, 

provided suggestions on designing a public involvement process that would be meaningful to participants 

to help identify a starting point from which to build the Proposed Action. Approximately twenty
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 1: Purpose and Need

Tahoe National Forest – 11

individuals assisted with this effort, which was open to the public. In the fall, 2006, using the suggestions 

from the public on how to structure the public involvement, a series of six workshops were initiated to 

recommend which routes and areas should become part of the Proposed Action, and the type of vehicle 

use that each would have. The concept of “mixed use” was also introduced during these meetings. At the 

first session of the two-part series, public workshops were held in Nevada City (Oct. 19), Truckee (Oct. 

23) and Foresthill (Oct. 26). At these meetings, participants broke into three groups to review three 

different geographical areas and to discuss which of the routes they would or would not like to become 

part of the Proposed Action. Some of the groups continued to meet and/or to make field visits to review 

conditions on the ground. Later in the fall, at the second set of public workshops, these groups returned 

and presented their information back to the entire group at sessions in Grass Valley (Nov. 15), Truckee 

(Dec. 5) and Foresthill (Dec. 7). Public meeting participants shared their ideas and their various concerns 

with other group proposals. Roughly 300 people participated in these public workshops. In early 2007, an 

e-mail update was issued sharing information on the meetings and the outcome. The Forest Service 

Interdisciplinary team took this information and used it in the development of the Proposed Action for the 

Notice of Intent.

30-day public scoping period for the Notice of Intent

In April 2007, the Forest Service published the “Proposed Action and Notice of Intent to Prepare an 

Environmental Impact Statement” (Federal Register Vol. 72/No. 69/Wednesday April 11, 2007) based on 

comments from the meetings held in the fall. The public comment period began on April 11, 2007, and 

ended May 14, 2007. Presentations to a variety of groups, phone calls, news releases, website postings 

and emails were used to alert the public of the opportunity to comment on the Proposed Action. Public 

meetings were held in Truckee (April 18), in Foresthill (April 24) and in Grass Valley (April 26) to 

explain the Proposed Action. Over 3,500 comments were received via e-mail and regular mail; with most 

being e-mail form letters.

Issues_________________________________________________

Comments from the public, other agencies, and the Tribes were used to formulate issues concerning the 

Proposed Action (see Project Record). An issue is a matter of public concern regarding the Proposed 

Action and its environmental impacts. Scoping identified issues which are a point of discussion, dispute, 

or debate with the Proposed Action. An issue is an effect on a physical, biological, social, or economic 

resource. An issue is not an activity; instead, the predicted effects of the activity create the issue. The 

Forest Service separated the issues into two groups: significant and non-significant. Significant Issues are 

defined as those directly or indirectly caused by implementing the Proposed Action. 

Significant Issues are used to formulate alternatives, prescribe mitigation measures, or analyze 

environmental effects. Issues are significant because of the extent of their geographic distribution, the 

duration of their effects, or the intensity of interest or resource conflicts. Non-Significant Issues were 

identified as those that were: 1) outside of the scope of the Proposed Action; 2) already determined 

through law, regulation, Forest Plan, or other higher level decision; 3) irrelevant to the decision to be 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 1: Purpose and Need

12 – Tahoe National Forest

made; 4) conjectural and not supported by scientific fact; 5) a comment, opinion, or position statement; 

or, 6) a question for clarification or information. Although non-significant issues are not used to formulate 

alternatives or prescribe mitigation measures, the EIS will disclose significant environmental effects 

including any related to non-significant issues. 

The Council on Environmental Quality (CEQ) NEPA regulations explain this delineation in Sec. 

1501.7, “...identify and eliminate from detailed study the issues which are not significant or which have 

been covered by prior environmental review (Sec. 1506.3)...” A list of non-significant issues and reasons 

why they were found non-significant may be found in the Project Record.

As described above, issues are significant because of the extent of their geographic distribution, the 

duration of their effects, or the intensity of interest or resource conflicts. The IDT used the following 

Significant-Issue Statements to formulate and compare alternatives, prescribe mitigation measures, or 

analyze and compare the environmental effects of each alternative. The Significant-Issue Statements 

identify elements (individual elements or groups of significant issue topics) along with a cause and effect 

based on public comments. Based on public comment, the IDT identified the significant issues shown in 

Table 1-4.

Table 1-4. Significant Issues

Issue/Element Cause and Effect

Significant Issue Statement #1. The route inventory identified approximately 1,596.3 miles of existing unauthorized 

routes and the Proposed Action only adds 36.7 miles of these to the NFTS. Reducing the miles of routes available for 

public motorized use and prohibiting cross country travel as described in the Proposed Action will adversely affect the 

quality and quantity of motorized recreation experiences

Motorized Recreation 

Opportunities

• Does not provide adequate access to key destinations, including campsites, scenic 

overlooks, and hunting areas.

• Reduces loops and connectors to provide longer riding time and spurs for exploration.

• Reduces the diversity of opportunities for different vehicles (ATVs, motorcycles, 

4WD).

• Reduces semi-primitive riding opportunities and experiences.

Significant Issue Statement #2. Public motorized use of roads and trails as described in the Proposed Action will 

adversely affect non-motorized recreation experiences.

Non-Motorized 

Recreation Opportunities

• Increases in engine noise will impact non-motorized recreation opportunities.

• Increases in dust will impact non-motorized recreation opportunities.

• Increases in motorized use will result in user conflicts between forest visitors.

• Increases in motorized use will reduce aesthetic values.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 1: Purpose and Need

Tahoe National Forest – 13

Issue/Element Cause and Effect

Significant Issue Statement #3. Public motorized use of roads and trails as described in the Proposed Action will 

adversely affect forest resources.

Resource Impacts • Increased erosion, soil compaction, and reduction in water quality;

• Degradation of habitat for fish, wildlife, and rare plants;

• Damage to heritage resources;

• Proliferation of weeds; and

• Impacts to Inventoried Roadless Area character compromising future potential 

wilderness designation.

Significant Issue Statement #4: The NFTS is already too large to provide adequate maintenance and 

administration. 

Affordability • Current and future budgets may not provide adequate funding for maintenance, 

administration and enforcement of the proposed road and trail system.

• Additions to the NFTS may require additional mitigation measures to prevent serious 

and adverse environmental impacts.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 1: Purpose and Need

14 – Tahoe National Forest
Chapter 2 

The Alternatives 

Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Tahoe National Forest – 15

Chapter 2: The Alternatives

This chapter describes and compares the alternatives considered for the Tahoe National Forest Motorized 

Travel Management EIS. It describes both alternatives considered in detail and those eliminated from 

detailed study. The end of this chapter presents the alternatives in tabular format so that the alternatives 

and their environmental impacts can be readily compared. 

Based on the issues identified through public comment on the Proposed Action, the Forest Service 

developed five action alternative proposals to the Proposed Action alternatives that achieve the purpose 

and need differently than the Proposed Action. In addition, the Forest Service is required to analyze a No 

Action Alternative. The Proposed Action, alternatives to the Proposed Action, and the No Action 

Alternative are described in detail below. This chapter is divided into five parts:

• How the alternatives were developed;

• Elements common to all alternatives, including motorized mixed use, routine maintenance, 

mitigation measures, monitoring and implementation strategy.

• Alternatives considered in detail, including cross country travel, additions to the National Forest 

Transportation System (NFTS), establishment of motorized “Open Areas,” changes to the NFTS, 

and proposed Forest Plan amendments;

• Alternatives that were considered, but eliminated from detailed analysis. This section includes the 

rationale for eliminating these alternatives; and

• Comparison of the alternatives.

How the Alternatives Were Developed ______________________

The Forest Service used the significant issues listed in Chapter 1 to develop the alternatives to the 

Proposed Action. The alternatives provide different approaches to:

• Fulfill the purpose and need for the project as described in Chapter 1, and 

• Address the significant issues. 

In addition to the issues raised during the 30-day public scoping period, two groups submitted 

alternative proposals for consideration by the Forest Service. The six action alternatives incorporate 

elements of these proposals as well as other comments submitted by the public. In addition, information 

gathered by the Forest Service in their consultation and discussions with tribal representatives, local 

counties, State and Federal agencies, and Forest Service employees was used to develop and refine the 

alternatives.

Modifications to Alternatives between Draft

and Supplemental Draft Environmental Impact Statement______

The following modifications were to the alternatives as they were displayed in the Draft Environmental 

Impact Statement.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

16 – Tahoe National Forest

• The corrections to the existing NFTS as described in Chapter 1 were incorporated into each of the 

alternatives.

• Modifications were made to the Preferred Alternative (Alternative 6) in response to public 

comments on the Draft EIS including:

§ Shortened the seasonal restrictions on motorized vehicle use by one month for routes on the 

westside of the Forest to enhance opportunities for motorized recreation.

§ Allowed wheeled over-the-snow motorized vehicle use on 3.6 miles of the Fordyce jeep trail 

when 15 inches of snow is present on the ground. 

§ Increased protection for the Forest’s Inventoried Roadless Areas (IRAs) not to adding Route 

YRN-M3b, located in the West Yuba IRA, to the NFTS. 

§ Limited year-round motorized mixed use (highway-legal vehicles sharing roads with nonhighway legal vehicles) to roads less than 3 miles in length that have a low mixed use crash 

probability combined with a low mixed use crash severity, or that are consistent with the 

California Vehicle Code Division 16.5. 

§ Allowed motorized mixed use on certain roads longer than 3 miles, but only during deer 

hunting season, which ensures a low mixed use crash probability and severity will be 

maintained on these roads. 

§ Allowed motorized mixed use on certain routes recommended by the public during the 

comment period. These routes, which have been identified in our NFTS objectives as 

Maintenance Level 3 roads (typically low speed, single lane roads with turnouts maintained for 

travel by a prudent driver in a standard passenger car), will now be maintained as Maintenance 

Level 2 roads (roads open for use by high clearance vehicles). 

§ Ensured that the public has adequate access to important non-motorized recreation 

opportunities on the Forest by allowing such places to be safely reached in highway legal 

vehicles. 

§ Added numerous, primarily short unauthorized route segments recommended by the public, to 

the NFTS to provide motorized access to dispersed recreation sites where no significant 

adverse resource impacts were associated with such additions.

§ Established “Open Areas” at the Boca, Stampede, and Prosser Reservoirs to provide motorized 

access to the shorelines. 

§ Incorporated additional mitigation measures for specific routes to minimize impacts associated 

with motorized vehicle use, which will allow these routes to be added to the NFTS in a 

sustainable manner.

Elements Common to All Alternatives ______________________

Motorized Mixed Use

Forest Service Manual (FSM) 7705 defines motorized mixed use as the designation of an NFTS road for 

use by both highway-legal and non-highway-legal motor vehicles. The Forest Service considers roads 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

Tahoe National Forest – 17

maintained for use by high clearance vehicles (Maintenance Level 2) as roughly graded and considers 

operation of non-highway legal vehicles on these roads to be consistent with state law. 

The following proposals related to motorized mixed use apply to all action alternatives:

• Vehicle classes allowed on unauthorized routes added to the NFTS as roads. Unauthorized 

routes considered for addition to the NFTS under one or more of the action alternatives have been 

determined not to have significant safety concerns that could not be mitigated (Appendix A, Site 

Specific Road, Trail and Open Area Information). All vehicle classes (including highway-legal and 

non-highway-legal vehicles) would be allowed if the route is added to the NFTS as a road. Use by 

non-highway-legal trail vehicles would be allowed on routes added to the NFTS as motorized 

trails.

• Vehicle classes allowed on existing NFTS high clearance 4WD roads. All existing high 

clearance NFTS four-wheel drive (4WD) roads have been determined to have minimal safety 

concerns (see Transportation section). All vehicles classes (including highway-legal and nonhighway-legal vehicles) would be allowed on these types of roads in all action alternatives 

(Alternatives 2-7).

• Vehicle classes allowed on existing NFTS passenger car roads. Roads currently maintained for 

passenger cars are being considered for mixed use where such use is currently prohibited. (See 

Transportation section in Chapter 3 for more information.) All vehicle classes (highway-legal and 

non-highway-legal vehicles) would be allowed to use all or segments of these roads in the action 

alternatives (Alternatives 2-7). Non-highway-legal vehicles would not be allowed on any other 

passenger car roads, and operators of non-highway legal vehicles on roads where mixed use is 

allowed would be required to possess a valid driver’s license and insurance.

Parking 

Under all action alternatives, parking would be restricted to one vehicle length off of designated roads and 

motorized trails.

Routine Maintenance 

Maintenance is defined as ongoing upkeep of a road necessary to maintain or restore the road in 

accordance with its road management objectives (FSM 7714). Under all alternatives, an annual 

maintenance plan for NFTS roads and trails would be developed at the beginning of the road maintenance 

season. Routine maintenance includes cleaning and repairing drainage structures (i.e., water bars, culverts 

and rolling dips); berm removal; clearing the travel surface of obstacles such as rock, slough, trees, and 

brush; clearing obstacles such as downed trees; blocking and naturalizing multiple routes or shortcuts; and 

incidental replacement or repair of existing structures such as barriers, walls, or causeways.

Roads and trails in need of maintenance at the beginning of the maintenance season (e.g., to address 

concerns related to spring run off, winter tree and snag fall and other environmental factors) are the first 

priority. Later in the season, maintenance focuses on maintaining high traffic volume roads; major repairs 

such as culvert replacement; and repairs needed to prevent or mitigate resource damage.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

18 – Tahoe National Forest

Mitigation Measures

Mitigation measures would be required for any of the motorized roads or trails proposed for addition to 

the NFTS and established “Open Areas” in any of the action alternatives. Mitigation measures are 

contained in Appendix A (Site Specific Road, Trail and Open Area Information). The mitigation measures 

fall in the following general categories. See Table 2-1 for the summary of proposed mitigation measures.

Table 2-1. Summary of Proposed Mitigation Measures by Alternative

Alt 2 Alt 4 Alt 5 Alt 6 Alt 7

Watershed (includes improving stream 

crossings, placing drainage structures, 

repairing gullies, minor rerouting, placing 

barriers, removing structures, constructing

waterbars, and closing adjacent spurs)

Routes 36 11 37 28 25

Acres

Miles

60

41.5

0

16.6

0

42.4

244

34.6

0

30.4

Cost $154,700 $65,500 $136,200 $43,200 $119,500

Botany (includes installing waterbars, 

placing barriers, minor reroutes and 

noxious weed removal)

Routes 17 8 19 14 13

Acres

Miles

2,589 

23.7

0

12.8

0

23.7

244

19.0

0

19.1

Cost $42,350 $6,250 $43,750 $22,550 $37,250

Wildlife (includes placing barriers and 

conducting bat surveys)

Routes 2 0 2 3 1

Miles .5 0 .5 .5 .2

Cost $1,000 0 $1,000 $1,500 $500

Safety (includes closing adits, approving 

mixed use, installing signs, removing logs 

and labeling water sources)

Routes 6 1 6 6 3

Miles 5.9 2.9 5.9 5.9 3.6

Cost $6,000 $500 $6,000 $6,000 $2,000

Lands (includes completing law 

enforcement agreements and obtaining 

permission from private landowners)

Routes 6 3 19 4 6

Acres

Miles

60

6.4

0

1.9

0

14.6

0

3.2

0

6.3

Cost $2,250 $750 $5,000 $1,250 $1,750
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

Tahoe National Forest – 19

Alt 2 Alt 4 Alt 5 Alt 6 Alt 7

Recreation (includes placing barriers, 

removing obstructions and restricting to day 

use only)

Routes 9 4 9 14 5

Miles 4.6 1.5 4.6 4.0 4.3

Cost $5,500 $2,000 $5,500 $8,000 $3,500

Air Quality (encapsulating asbestos) Routes 1 0 3 1 1

Miles .6 0 1.2 .5 .6

Cost $10,000 0 $30,000 $10,000 $10,000

Heritage (installing barriers) Routes 5 2 6 5 2

Acres

Miles

2,589

6.5

0

2.0

0

7.0

0

5.0

0

2.4

Cost $8,850 $3,850 $8,350 $5,850 $3,850

Total Routes with Mitigation 44 15 60 47 27

Total Acres and 

Miles with Mitigation

2,649 

Acres

43.8

Miles

18.2

Miles

54.2

Miles

244 

Acres

37.7

Miles

30.0

Miles

Total Cost with Mitigation $240,650 $77,850 $256,300 $103,350 $173,350

Note: Table 2-1 does not list any mitigation measures for Alternatives 1and 3 because there are no roads, trails, or areas being 

added to the National Forest Transportation System. Numbers may not add up due to rounding. Totals do not sum due to multiple 

mitigations required for individual routes.

Scheduling of mitigation measures would be based on the following considerations: 

• Roads and trails where the location or deteriorated condition is causing substantial effects to 

riparian, watershed, threatened, endangered or sensitive species, or significant cultural resources 

whether or not motorized vehicle use is occurring.

• Mitigations on routes requiring relatively low-cost, easily implemented work, such as signage or 

simple barriers.

• Roads and trails that provide connectivity and important access for the transportation network or 

other routes that have been identified as providing key public benefit and opportunities.

Routes with mitigations would not be open to motorized use until this work is accomplished. After 

mitigation has been performed, the route would appear as a designated public motorized road or trail on 

the next revision of the MVUM. Mitigations have been analyzed for their potential to reduce or eliminate 

effects on specific resources associated with motorized use of the routes. These effects are disclosed in the 

resource sections of Chapter 3.

Monitoring

Monitoring is critical for evaluating the effectiveness of management decisions and the accuracy of 

analysis assumptions and conclusions. Monitoring of road and trail conditions is required, and must meet 

regional and/or national standards. If monitoring determines additional resource damage is occurring,

steps to prevent further damage may be taken. If the mitigations are not effective or are not possible, 

additional road or trail closures may be required and would require additional NEPA analysis.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

20 – Tahoe National Forest

Proposed route-specific monitoring varies by alternative. As identified in Appendix A (Site Specific Road, 

Trail and Open Area Information), resource specialists have identified approximately 84 routes where 

site-specific monitoring would be needed if the routes are added to the system for public use in an 

alternative. These include monitoring effects of the routes on botany, heritage, watershed and recreation 

resources. In some cases, one route may be monitored to assess conditions of multiple resources.

In addition to effectiveness monitoring related to the actions of this project, many other forms of 

monitoring and data collection take place on the Forest. These include ongoing monitoring that is already 

prescribed, such as surveys of roads and trails for infrastructure condition, monitoring of cultural resource 

sites, noxious weed spread, rare plants, or wildlife surveys. Some of this monitoring may directly or 

indirectly assess the effects of roads or trails on resources, as well as generally assessing conditions of 

roads for stability and maintenance. While these monitoring efforts are not prescribed in this Travel 

Management EIS, these data would also be used whenever possible, in assessing either the effectiveness 

of the actions proposed or in adjusting future travel management actions. The Forest Service would 

conduct implementation monitoring based on Appendix M (OHV Monitoring) and summarized in Table 

2-2.

Table 2-2. Summary of number of routes with monitoring requirements by resource category and alternative

Resource Category Alt 2 Alt 4 Alt 5 Alt 6 Alt 7

Botany (Number of routes) 5 1 5 6 4

Heritage (Number of routes) 48 18 50 65 9

Watershed (Number of routes) 13 4 16 16 13

Recreation (Number of routes) 1 0 1 1 0

Grand Total (Number of routes)

(Total cost)

67

$20,865

23

$5,755

72

$21,115

88

$24,020

26

$9,250

Note: Table 2-2 does not list monitoring requirements for Alternatives 1 and 3 because there are no roads or trails being added to 

the NFTS. 

Implementation Strategy

After a decision is made, a Motor Vehicle Use Map (MVUM) would be created and made available to the 

public at no cost. This map would be the legal document displaying designated NFTS roads, trails, and 

established “Open Areas” on the Forest which may be legally traveled with a motorized vehicle, as well 

as the allowed vehicle class, and any seasonal or other use restrictions. As changes or corrections are 

made to the transportation system in the future, the MVUM would be periodically revised and reissued.

NFTS roads and trails open to public use would be signed on the ground with a road or trail number and 

any regulatory information that may apply to the route.

Alternatives Considered in Detail __________________________

The action alternatives (Alternatives 2, 3, 4, 5, 6 and 7) and the No Action Alternative (Alternative 1) are 

considered in detail. The No Action Alternative represents the continuation of cross country travel 

including continued use of all unauthorized routes by motor vehicles. Alternative 1, required by the 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

Tahoe National Forest – 21

implementing regulations of the National Environmental Policy Act (NEPA), serves as a baseline for 

comparison among the alternatives.

The planning area includes National Forest System land on the Tahoe National Forest. It does not 

include any private, state or other federal lands. Each alternative assumes that other adjacent federal lands

will be managed according to existing management plans and applicable federal laws. Each alternative 

also assumes that private lands will meet applicable state and federal land use regulations. 

The alternatives are described in five parts:

1. Cross Country Travel: All of the action alternatives prohibit wheeled motor vehicle travel off 

designated NFTS roads, NFTS motorized trails, and established “Open Areas” by the public 

except as allowed by permit or other authorization. Prohibition of cross country travel addresses

the need to regulate unmanaged motor vehicle use.

2. Additions to the NFTS: Some action alternatives would add unauthorized routes as roads and 

trails to the NFTS by vehicle class and season of use. Additions are considered in order to 

respond to the need to provide motor vehicle access to dispersed recreation opportunities and to 

provide a diversity of motorized recreation opportunities. For purposes of this analysis, each of 

these roads and trails is identified by a unique number. Resource specialists conducted their site 

specific review of each proposed route. All proposed route additions have assigned road or trail 

management objectives. All proposed additions would receive the appropriate level of routine 

maintenance, such as brushing, signing, cleaning and clearing debris. For some routes, no work 

beyond routine maintenance would be needed. For others, additional mitigation would be needed 

to bring the route up to a safe and environmentally sustainable condition. The specific 

mitigations must be completed prior to designation of the route on the MVUM for public 

motorized use. Appendix A (Site Specific Road, Trail and Open Area Information) shows the 

specified vehicle class, season of use, and mitigations for all proposed route additions.

Additional details on each route are contained in the Project Record.

3. Establishment of Motorized “Open Areas”: Two action alternatives would establish motorized 

“Open Areas” by vehicle class and season of use. Establishing new “Open Areas” are being 

considered in order to respond to the need to provide motor vehicle access for dispersed 

recreation opportunities and to provide a diversity of motorized recreation opportunities. For 

purposes of this analysis, each of these “Open Areas” is identified by name. Resource specialists 

conducted their site specific review of each proposed “Open Area.” All established “Open Areas”

would receive the appropriate level of routine maintenance such as brushing, signing, cleaning

and clearing debris. For some “Open Areas”, no work beyond routine maintenance would be

needed. For others, additional mitigation is needed to bring the area up to a safe and 

environmentally sustainable condition. The specific mitigations must be completed prior to 

establishment of the “Open Area” on the MVUM for public motorized use. Appendix A shows

the specified vehicle class, season of use and mitigations for all proposed established “Open 

Areas.” Additional details on each “Open Area” are contained in the Project Record.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

22 – Tahoe National Forest

4. Changes to the NFTS: With the exception of Alternative 3, the action alternatives propose 

various changes to the existing NFTS including changes to vehicle class and season of use, and 

reopening Maintenance Level 1 roads. Appendix A (Site Specific Road, Trail and Open Area 

Information) shows the specified vehicle class, season of use, and mitigations for proposed 

changes to the existing NFTS under each alternative.

a. Vehicle class - The action alternatives may include limited changes to the vehicle class 

allowed on existing NFTS roads and/or trails. Vehicle class indicates the type of vehicle 

(passenger car, motorcycle, all-terrain vehicle, etc) allowed to operate on a road or trail. Some 

alternatives add vehicle classes to roads and/or trails where that use is currently prohibited.

Some alternatives add vehicle classes resulting from changes in maintenance levels. These 

changes respond to the need to provide a diversity of wheeled motorized recreation 

opportunities and access. 

b. Season of Use - The action alternatives vary in terms of which roads, trails and areas would 

have motorized travel prohibited during specified times of year. Wet weather seasonal 

restrictions are specified in some of the alternatives to minimize erosion and protect water 

quality.

c. Reopening Maintenance Level 1 Roads - Some alternatives include opening Maintenance 

Level 1 (ML 1) roads to public use, where such use is currently prohibited, to enhance 

motorized recreation opportunities. These changes respond to the need to provide a diversity 

of wheeled motorized recreation opportunities and access.

5. Amendments to the Forest Plan: Some of the action alternatives include an amendment to the 

Tahoe National Forest Land and Resource Management Plan (LRMP 1990) to remove the 

November 1 to May 1 seasonal closure in the Sugar Pine area (Management Area 84 Humbug 

Sailor) on key winter deer range to improve motorized recreation opportunities.

Alternative 1: No Action

The No Action Alternative provides a baseline for comparing the other alternatives. Under the No Action 

Alternative, no changes would be made to the NFTS and there would be no prohibition of cross country

travel (see Table 2-3). Current management plans would continue to guide project area management. The 

Travel Management Rule would not be implemented, and no motor vehicle use map (MVUM) would be 

published. Motor vehicle travel by the public would not be limited to designated routes. Unauthorized 

routes would continue to proliferate and would have no status or authorization as NFTS facilities.

1. Cross Country Travel: Public wheeled motor vehicle travel off designated NFTS roads, NFTS 

trails, and outside established “Open Areas” would continue, except as otherwise prohibited.

2. Additions to the NFTS: No unauthorized routes would be added to the NFTS as roads or 

motorized trails under this alternative.

3. Establishment of Motorized “Open Areas”: No additional motorized “Open Areas” would be 

established under this alternative.

4. Changes to the NFTS: No Changes to the NFTS would be made in this alternative.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

Tahoe National Forest – 23

5. Amendments to the Forest Plan: No amendments would be made to the Forest Plan.

Table 2-3 displays a summary of the existing conditions due to no action in this alternative. A map 

displaying this alternative is included in digital format on the CD attached to this document, and may be 

found in the Project Record located at the Tahoe National Forest Supervisors Office in Nevada City, 

California.

Table 2-3. Alternative 1 - Summary of Actions (Existing Condition)

Action type Action Proposed

1. Cross Country Travel (Acres) Prohibitions continue

on 81,975 acres.

Continues on 754,066

acres

2. Additions to the NFTS a. Roads added to the NFTS open to high clearance 

vehicles

0.0 (miles), 0 (roads)

b. Motorized Trails added to the NFTS 0.0 (miles)

0 (trails)

3. Establishment of Motorized “Open Areas” None

4. Changes to the NFTS a. Passenger car roads where both highway legal and 

non-highway legal vehicles will be allowed to use the 

same road.

0.0 miles

b. Passenger car roads that will be downgraded to high 

clearance roads so that both highway legal and nonhighway legal vehicles can use the same road

0.0 miles

c. Change in Season of Use 0.0 miles

d. Reopening Maintenance Level 1 Roads 0.0 (miles), 0 (roads)

5. Amendments to the Forest Plan None

Alternative 2: Increased Motorized Recreation

and Access Opportunities

Alternative 2 responds to the issue of inadequate motorized recreation opportunities. This alternative is 

based on the Proposed Action (Alternative 7), with additional routes and mixed use to provide more 

access and motorized recreation opportunities. During scoping, the Tahoe National Forest received 

numerous site specific suggestions for additional motorized roads, trails and established “Open Areas” 

that would improve public access and enhance motorized recreation opportunities. Unauthorized routes

and closed NFTS roads site-specifically requested by the public during scoping were added in this

alternative, provided they were consistent with law, regulation, and policy. In addition, site specific 

recommendations for “Open Areas” proposed by the public during scoping were also established in this 

alternative provided they were consistent with law, regulation and policy.

1. Cross Country Travel: Public wheeled motor vehicle travel off designated NFTS roads, NFTS 

trails, and outside established motorized use areas would be prohibited, except as allowed by 

permit or other authorization.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

24 – Tahoe National Forest

2. Additions to the NFTS:

a. Under this alternative, 114 segments of unauthorized routes totaling 5.0 miles would be 

added as roads open to high clearance vehicles to the NFTS.

b. 54.6 miles (87 routes) of unauthorized routes would be added as motorized trails to the 

NFTS.

3. Establishment of Motorized “Open Areas”: Four areas totaling 2,649 acres would be 

established as motorized “Open Areas” open to all vehicles under this Alternative.

4. Changes to the NFTS: 

a. Change Vehicle Classes through Mixed Use: Change vehicle class on 241.5 miles to allow 

licensed operators of non-highway legal vehicles to operate on NFTS roads where such use is 

currently prohibited through approval of mixed use.

b. Change Vehicle Classes through Maintenance Levels: Change vehicle class on 157.2 miles 

to allow licensed operators of non-highway legal vehicles to operate on NFTS roads where 

such use is currently prohibited through the conversion of Maintenance Level 3 (ML 3) roads 

to Maintenance Level 2 (ML 2). For each of these roads an entrance strategy (i.e. waterbars) 

and road conditions would be implemented to be consistent with use by high clearance 

vehicles. These roads would then be maintained as ML 2 to prevent unacceptable resource 

damage from occurring. Once the Forest Engineer determines these roads have reached ML 2 

conditions they would be placed on the MVUM and signed as available for use by nonhighway legal vehicles.

c. Changes in Seasonal Restrictions: Seasonal restrictions for deer winter range would be 

changed from “May 1 to November 1”, to “Open Year Round” on 10.5 miles of roads 

resulting from the Forest Plan Amendment to Management Area 84 (Humbug-Sailor)

d. Reopening Maintenance Level 1 Roads: No ML 1 roads would be opened to motorized use.

6. Amendments to the Forest Plan: The Tahoe National Forest LRMP would be amended to 

remove the November 1 to May 1 seasonal closure in the Sugar Pine area (Management Area 84 

Humbug Sailor) on key winter deer range to improve motorized recreation opportunities.

Table 2-4 displays a summary of the actions proposed in this alternative. A complete listing of roads, 

trails and areas to be added into the NFTS; including the vehicle class and, if applicable, seasonal use 

restrictions; can be found in Appendix A (Site Specific Road, Trail and Open Area Information). A map 

displaying this alternative is included in digital format on the CD attached to this document, and may be 

found in the Project Record located at the Tahoe National Forest Supervisors Office in Nevada City, 

California.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

Tahoe National Forest – 25

Table 2-4. Alternative 2 - Summary of Actions

Action type Action Proposed

1. Cross Country Travel (Acres) Prohibited on

833,392 acres

2. Additions to the NFTS a. Roads added to the NFTS 5.0 (miles), 114 (roads)

b. Motorized Trails added to the NFTS

 Trails open to high clearance trail vehicles

 Trails open to ATVs and motorcycles only

 Trails open to motorcycles only

 Total all trails

24.3 (miles), 69 (trails)

4.4 (miles), 3 (trails)

25.9 (miles), 15 (trails)

54.6 (miles), 87 (trails)

3. Establishment of Motorized “Open Areas” Greenhorn Area (60 

acres) Prosser, Boca 

and Stampede 

Reservoirs (2,589 

acres)

4. Changes to the NFTS a. Passenger car roads where both highway legal and nonhighway legal vehicles will be allowed to use the same road241.5 (miles)

b. Passenger car roads that will be downgraded to high 

clearance roads so that both highway legal and non-highway 

legal vehicles can use the same road

157.2 (miles)

c. Change in Season of Use 10.5 (miles)

d. Reopening Maintenance Level 1 Roads 0.0 (miles), 0 (roads)

5. Amendments to the Forest Plan Management Area 84 

(Humbug Sailor) Deer 

Winter Range Seasonal 

Restriction Removed

Alternative 3: Cross Country Travel Prohibition Only –

No Changes to the Existing National Forest Transportation System

Alternative 3 responds to issues of (1) adverse effects of motorized recreation use on non-motorized 

recreation experiences and (2) potential adverse impacts from motorized recreation use on natural and 

cultural resources. As such, Alternative 3 would prohibit cross country travel, and proposes no new 

additions to the NFTS. This alternative also provides a baseline for comparing the impacts of other 

alternatives that propose changes to the NFTS. None of the unauthorized roads or trails would be added to 

the NFTS. No additional “Open Areas” would be established.

1. Cross Country Travel: Public wheeled motor vehicle travel off designated NFTS roads, NFTS 

trails, and outside established motorized use areas would be prohibited, except as allowed by 

permit or other authorization.

2. Additions to the NFTS: No unauthorized routes would be added to the NFTS as roads or 

motorized trails under this alternative. 

3. Establishment of Motorized “Open Areas”: No additional motorized “Open Areas” would be 

established under this alternative.

4. Changes to the NFTS: No changes to the NFTS would be made in this alternative.

5. Amendments to the Forest Plan: No amendments would be made to the Forest Plan.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

26 – Tahoe National Forest

Table 2-5 displays a summary of the actions proposed in this alternative. A map displaying this 

alternative is included in digital format on the CD attached to this document, and may be found in the 

Project Record located at the Tahoe National Forest Supervisors Office in Nevada City, California.

Table 2-5. Alternative 3 - Summary of Actions

Action type Action Proposed

1. Cross Country Travel (Acres) Prohibited on

836,000 acres

2. Additions to the NFTS a. Roads added to the NFTS 0.0 (miles), 0 (trails)

b. Motorized Trails added to the NFTS 0.0 (miles), 0 (trails)

3. Establishment of Motorized “Open Areas” None

4. Changes to the NFTS a. Passenger car roads where both highway legal and nonhighway legal vehicles will be allowed to use the same road0.0 (miles)

b. Passenger car roads that will be downgraded to high 

clearance roads so that both highway legal and non-highway 

legal vehicles can use the same road

0.0 (miles)

c. Change in Season of Use 0.00

d. Reopening Maintenance Level 1 Roads 0.0 (miles), 0 (roads)

5. Amendments to the Forest Plan None

Alternative 4: Increased Resource Protection

Alternative 4 responds to issues of (1) adverse effects of motorized recreation use on non-motorized 

recreation experiences and (2) potential adverse impacts from motorized recreation use on natural and 

cultural resources. It addresses these issues by prohibiting cross country travel and adding fewer routes to 

the NFTS than the Proposed Action. Alternative 4 is based on the Proposed Action contained in the 

Notice of Intent as modified by an alternative submitted by an environmental group coalition during 

scoping.

1. Cross Country Travel: Public wheeled motor vehicle travel off designated NFTS roads, NFTS 

trails, and outside established motorized use areas would be prohibited, except as allowed by 

permit or other authorization.

2. Additions to the NFTS:

a. Under this alternative, 85 segments of unauthorized routes totaling 3.7 miles would be added 

as roads open to high clearance vehicles to the NFTS.

b. 22.6 miles (27 routes) of unauthorized routes would be added as motorized trails to the 

NFTS.

3. Establishment of Motorized “Open Areas”: No additional motorized “Open Areas” would be 

established under this alternative.

4. Changes to the NFTS: 

a. Change Vehicle Classes through Mixed Use: No changes would be made to allow licensed 

operators of non-highway legal vehicles to operate on NFTS roads where such use is 

currently prohibited through approval of mixed use.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

Tahoe National Forest – 27

b. Change Vehicle Classes through Maintenance Levels: Change vehicle class on 3.4 miles to 

allow licensed operators of non-highway legal vehicles to operate on NFTS roads where such 

use is currently prohibited through the conversion of ML 3 roads to ML 2. For each of these 

roads an entrance strategy (i.e. waterbars) and road conditions would be implemented to be 

consistent with use by high clearance vehicles. These roads would then be maintained as ML 

2 to prevent unacceptable resource damage from occurring. Once the Forest Engineer 

determines these roads have reached ML 2 conditions they would be placed on the MVUM 

and signed as available for use by non-highway legal vehicles.

c. Changes in Seasonal Restrictions: Wet weather seasonal closures would be added from 

January 1 to May 31 in the Burlington area and January 1 to April 30 on the remainder of the 

Forest on native surface roads and motorized trails. A total of 1,312.1 total miles would have 

changes in seasonal restrictions.

d. Reopening Maintenance Level 1 Roads: One ML 1 road (.1 miles) would be reopened to 

motorized use.

5. Amendments to the Forest Plan: No amendments would be made to the Forest Plan.

Table 2-6 displays a summary of the actions proposed in this alternative. A complete listing of roads, 

trails and areas to be added into the NFTS; including the vehicle class and, if applicable, seasonal use 

restrictions; can be found in Appendix A (Site Specific Road, Trail and Open Area Information). A map 

displaying this alternative is included in digital format on the CD attached to this document, and may be 

found in the Project Record located at the Tahoe National Forest Supervisors Office in Nevada City, 

California.

Table 2-6. Alternative 4 - Summary of Actions

Action type Action Proposed

1. Cross Country Travel (Acres) Prohibited on

836,000 acres

2. Additions to the NFTS a. Roads added to the NFTS open to high clearance vehicles 3.7 (miles), 85 (roads)

b. Motorized Trails added to the NFTS

 Trails open to high clearance trail vehicles

 Trails open to ATVs and motorcycles only

 Trails open to motorcycles only

 Total all trails

5.6 (miles), 19 (trails)

2.9 (miles), 1 (trail)

14.1 (miles), 7 (trails)

22.6 (miles), 27 (trails)

3. Establishment of Motorized “Open Areas” None

4. Changes to the NFTS a. Passenger car roads where both highway legal and nonhighway legal vehicles will be allowed to use the same road0.0 (miles)

b. Passenger car roads that will be downgraded to high 

clearance roads so that both highway legal and non-highway 

legal vehicles can use the same road

3.4 (miles)

c. Change in Season of Use 1,312.1 (miles)

d. Reopening Maintenance Level 1 Roads as trails open to 

Motorcycles only

0.1 (miles), 1 (road)

5. Amendments to the Forest Plan None
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

28 – Tahoe National Forest

Alternative 5: Increased Motorized Recreation Access plus Reopening 

Maintenance Level 1 and Temporary Roads

Alternative 5 responds to the issue of inadequate motorized recreation opportunities. This alternative is 

based on the Proposed Action contained in the Notice of Intent as modified by an alternative submitted by 

the Blue Ribbon Coalition during the scoping process. This alternative focuses on adding unauthorized 

routes to the NFTS and making changes to the existing NFTS to provide enhanced motorized vehicle 

access and motorized recreation opportunities across the Forest.

1. Cross Country Travel: Public wheeled motor vehicle travel off designated NFTS roads, NFTS 

trails, and outside established motorized use areas would be prohibited, except as allowed by 

permit or other authorization.

2. Additions to the NFTS:

a. Under this alternative, 112 segments of unauthorized routes totaling 5.0 miles would be 

added as roads open to high clearance vehicles to the NFTS.

b. 75.4 miles (141 routes) of unauthorized routes would be added as motorized trails to the 

NFTS.

3. Establishment of Motorized “Open Areas”: No additional motorized “Open Areas” would be 

established under this alternative.

4. Changes to the NFTS: 

a. Change Vehicle Classes through Mixed Use: Change vehicle class on 241.5 miles to allow 

licensed operators of non-highway legal vehicles to operate on NFTS roads where such use is 

currently prohibited through approval of mixed use.

b. Change Vehicle Classes through Maintenance Levels: Change vehicle class on 157.2 miles 

to allow licensed operators of non-highway legal vehicles to operate on NFTS roads where 

such use is currently prohibited through the conversion of ML 3 roads to ML 2. For each of 

these roads an entrance strategy (i.e. waterbars) and road conditions would be implemented to 

be consistent with use by high clearance vehicles. These roads would then be maintained as 

ML 2 to prevent unacceptable resource damage from occurring. Once the Forest Engineer 

determines these roads have reached ML 2 conditions they would be placed on the MVUM 

and signed as available for use by non-highway legal vehicles.

c. Changes in Seasonal Restrictions: Wet weather seasonal closures would be added from 

January 1 to May 31 in the Burlington area and January 1 to April 30 on the remainder of the 

Forest on native surface roads and motorized trails. A total of 1,396.7 total miles would have 

changes in seasonal restrictions.

d. Reopening Maintenance Level 1 Roads: One hundred thirteen ML 1 roads (93.4 miles) 

would be reopened to motorized use.

5. Amendments to the Forest Plan: The Tahoe National Forest LRMP would be amended to 

remove the November 1 to May 1 seasonal closure in the Sugar Pine area (Management Area 84 

Humbug Sailor) on key winter deer range.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

Tahoe National Forest – 29

Table 2-7 displays a summary of the actions proposed in this alternative. A complete listing of roads, 

trails and areas to be added into the NFTS; including the vehicle class and, if applicable, seasonal use

restrictions; can be found in Appendix A (Site Specific Road, Trail and Open Area Information). A map 

displaying this alternative is included in digital format on the CD attached to this document, and may be 

found in the Project Record located at the Tahoe National Forest Supervisors Office in Nevada City, 

California.

Table 2-7. Alternative 5 - Summary of Actions

Action type Action Proposed

1. Cross Country Travel (Acres) Prohibited on

836,000 acres

2. Additions to the NFTS a. Roads added to the NFTS open to high clearance 

vehicles

5.0 (miles), 112 (roads)

b. Motorized Trails added to the NFTS

 Trails open to high clearance trail vehicles

 Trails open to ATVs and motorcycles only

 Trails open to motorcycles only

 Total all trails

44.7 (miles), 120 (trails)

4.8 (miles), 5 (trails)

26.0 (miles), 16 (trails)

75.4 (miles), 141 (trails)

3. Establishment of Motorized “Open Areas” None

4. Changes to the NFTS a. Passenger car roads where both highway legal and nonhighway legal vehicles will be allowed to use the same road241.5 (miles)

b. Passenger car roads that will be downgraded to high 

clearance roads so that both highway legal and nonhighway legal vehicles can use the same road

157.2 (miles)

c. Change in Season of Use 1,396.7 (miles)

d. Reopening Maintenance Level 1 Roads (total)

 (as Roads open to all vehicles)

 (as Trails open to ATVs and motorcycles only)

 (as Trails open to motorcycles only)

93.4 (miles), 113 (roads)

79.3 (miles)

13.9 (miles)

0.1 (miles)

5. Amendments to the Forest Plan Management Area 84 

(Humbug Sailor) Deer 

Winter Range Seasonal 

Restriction Removed

Alternative 6: Preferred Alternative Motorized Access

and Resource Protection

Alternative 6 is the preferred alternative. It responds to issues of providing motorized public access and 

recreation opportunities while minimizing impacts to natural and cultural resources. It is designed to 

provide a diversity of road and trail opportunities for experiencing a variety of environments and modes 

of travel consistent with the National Forest’s recreation role and land capability. Alternative 6 would 

provide motorized access to dispersed recreation opportunities (camping, hunting, fishing, hiking, 

horseback riding, etc.) and a diversity of motorized recreation opportunities (4WD Vehicles, motorcycles, 

ATVs, passenger vehicles, and so forth). 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

30 – Tahoe National Forest

1. Cross Country Travel: Public wheeled motor vehicle travel off designated NFTS roads, NFTS 

trails, and outside established motorized use areas would be prohibited, except as allowed by 

permit or other authorization.

2. Additions to the NFTS:

a. Under this alternative, 346 segments of unauthorized routes totaling 13.1 miles would be 

added as roads open to high clearance vehicles to the NFTS.

b. 48.3 miles (106 routes) of unauthorized routes would be added as motorized trails to the 

NFTS.

3. Establishment of Motorized “Open Areas”: Under this alternative, three areas totaling 244 

acres would be established as motorized “Open Areas” open to highway legal vehicles only.

4. Changes to the NFTS: 

a. Change Vehicle Classes through Mixed Use: Change vehicle class on 130.8 miles to allow 

licensed operators of non-highway legal vehicles to operate on NFS roads where such use is 

currently prohibited through approval of mixed use. Of this total, approximately 117.5 miles 

would be open to mixed use only during deer hunting season (September 22 to November 4). 

Outside of hunting season, these roads would be open to highway legal vehicles only.

b. Change Vehicle Classes through Maintenance Levels: Change vehicle class on 122.0 miles 

to allow licensed operators of non-highway legal vehicles to operate on NFTS roads where 

such use is currently prohibited through the conversion of ML 3 roads to ML 2. For each of 

these roads an entrance strategy (i.e. waterbars) and road conditions would be implemented to 

be consistent with use by high clearance vehicles. These roads would then be maintained as 

ML 2 to prevent unacceptable resource damage from occurring. Once the Forest Engineer 

determines these roads have reached ML 2 conditions they would be placed on the MVUM 

and signed as available for use by non-highway legal vehicles.

c. Changes in Seasonal Restrictions: Wet weather seasonal closures from January 1 to May 31 

in the Burlington area and January 1 to April 30 on the remainder of the Forest on native 

surface roads and motorized trails would be added to minimize erosion and protect water 

quality. In addition, over the snow travel would be permitted on 3.6 miles of the Fordyce Jeep 

trail when 15 inches of snow is present on the ground. A total of 1,369.5 total miles would 

have changes to seasonal restrictions.

d. Reopening Maintenance Level 1 Roads: Thirteen ML 1 roads (11.4 miles) would be 

reopened to motorized use.

5. Amendments to the Forest Plan: The Tahoe National Forest LRMP would be amended to 

remove the November 1 to May 1 seasonal closure in the Sugar Pine area (Management Area 84 

Humbug Sailor) on key winter deer range.

Table 2-8 displays a summary of the actions proposed in this alternative. A complete listing of roads,

trails and areas to be added into the NFTS; including the vehicle class and, if applicable, seasonal use

restrictions; can be found in Appendix A (Site Specific Road, Trail and Open Area Information). A map 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

Tahoe National Forest – 31

displaying this alternative is included in digital format on the CD attached to this document, and may be 

found in the Project Record located at the Tahoe National Forest Supervisors Office in Nevada City, 

California.

Table 2-8. Alternative 6 - Summary of Actions

Action type Action Proposed

1. Cross Country Travel (Acres) Prohibited on

835,800 acres

2. Additions to the NFTS a. Roads added to the NFTS open to high clearance 

vehicles

13.1 (miles), 346 (roads)

b. Motorized Trails added to the NFTS

 Trails open to high clearance trail vehicles

 Trails open to ATVs and motorcycles only

 Trails open to motorcycles only

 Total all trails

22.6 (miles), 89 (trails)

4.8 (miles), 5 (trails)

20.9 (miles), 12 (trails)

48.3 (miles), 106 (trails)

3. Establishment of Motorized “Open Areas” Prosser, Boca and 

Stampede Reservoirs (244 

acres)

4. Changes to the NFTS a. Passenger car roads where both highway legal and 

non-highway legal vehicles will be allowed to use the 

same road

130.8 (miles)

b. Passenger car roads that will be downgraded to high 

clearance roads so that both highway legal and nonhighway legal vehicles can use the same road

122.0 (miles)

c. Change in Season of Use 1,369.5 (miles)

d. Reopening Maintenance Level 1 Roads (total)

 (as roads open to all vehicles)

 (as trails open to ATV’s and motorcycles only)

 (as trails open to motorcycles only)

11.4 (miles), 13 (roads)

2.7 (miles)

8.5 (miles)

0.1 (miles)

5. Amendments to the Forest Plan Management Area 84 

(Humbug Sailor) Deer 

Winter Range Seasonal 

Restriction Removed

Alternative 7: Proposed Action as Identified in Notice of Intent (NOI)

Alternative 7 is the Proposed Action as published in the Notice of Intent in the Federal Register.

1. Cross Country Travel: Public wheeled motor vehicle travel off designated NFTS roads, NFTS 

trails, and outside established motorized use areas would be prohibited, except as allowed by 

permit or other authorization.

2. Additions to the NFTS:

a. Under this alternative, no unauthorized routes would be added as roads to the NFTS.

b. 36.7 miles (36 routes) of unauthorized routes would be added as motorized trails to the 

NFTS.

3. Establishment of Motorized “Open Areas”: No additional motorized “Open Areas” would be 

established under this alternative.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

32 – Tahoe National Forest

4. Changes to the NFTS: 

a. Change Vehicle Classes through Mixed Use: No changes would be made to allow licensed 

operators of non-highway legal vehicles to operate on NFS roads, where such use is currently 

prohibited, through approval of mixed use.

b. Change Vehicle Classes through Maintenance Levels: Change vehicle class on 3.4 miles to 

allow licensed operators of non-highway legal vehicles to operate on NFTS roads where such 

use is currently prohibited through the conversion of ML 3 roads to ML 2. For each of these 

roads an entrance strategy (i.e. waterbars) and road conditions would be implemented to be 

consistent with use by high clearance vehicles. These roads would then be maintained as ML 

2 to prevent unacceptable resource damage from occurring. Once the Forest Engineer 

determines these roads have reached ML 2 conditions they would be placed on the MVUM 

and signed as available for use by non-highway legal vehicles.

c. Changes in Seasonal Restrictions: No changes in seasonal restrictions would be made.

d. Reopening Maintenance Level 1 Roads: Two ML 1 roads (1.1 miles) would be reopened to 

motorized use.

5. Amendments to the Forest Plan: No amendments would be made to the Forest Plan.

Table 2-9 displays a summary of the actions proposed in this alternative. A complete listing of roads, trails 

and areas to be added into the NFTS; including the vehicle class and, if applicable, seasonal use restrictions; 

can be found in Appendix A (Site Specific Road, Trail and Open Area Information). A map displaying this 

alternative is included in digital format on the CD attached to this document, and may be found in the Project 

Record located at the Tahoe National Forest Supervisors Office in Nevada City, California.

Table 2-9. Alternative 7 - Summary of Actions

Action type Action Proposed

1. Cross Country Travel (Acres) Prohibited on 836,000 

acres

2. Additions to the NFTS a. Roads added to the NFTS open to high clearance vehicles 0.0 (miles), 0 (roads)

b. Motorized Trails added to the NFTS

 Trails open to high clearance trail vehicles

 Trails open to ATVs and motorcycles only

 Trails open to motorcycles only

 Total all trails

16.9 (miles), 26 (trails)

3.4 (miles), 2 (trails)

16.4 (miles), 8 (trails)

36.7 (miles) 36 (trails)

3. Establishment of Motorized “Open Areas” None

4. Changes to the NFTS a. Passenger car roads where both highway legal and nonhighway legal vehicles will be allowed to use the same road0.0 (miles)

b. Passenger car roads that will be downgraded to high 

clearance roads so that both highway legal and non-highway 

legal vehicles can use the same road

3.4 (miles)

c. Change in Season of Use 0.0 (miles)

d. Reopening Maintenance Level 1 Roads (total)

 (as roads open to all vehicles)

 (as trails open to motorcycles only)

1.1 (miles) 2 (roads)

0.9 (miles)

0.1 (miles)

5. Amendments to the Forest Plan None
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

Tahoe National Forest – 33

Alternatives Considered but Eliminated from Detailed Study ___

NEPA requires that Federal agencies rigorously explore and objectively evaluate all reasonable 

alternatives and briefly discuss the reasons for eliminating any alternatives that were not developed in 

detail (40 CFR 1502.14). Public comments and internal scoping suggested the alternatives and are briefly 

described below along with a brief response discussing the reasons for eliminating them from detailed 

study.

Alternative A: Prohibit OHV (Non-Highway Legal) Use

This alternative would prohibit all non-highway legal use and allow only highway legal vehicles on the 

Tahoe National Forest. 

Response: Prohibiting all non-highway legal vehicles does not meet the purpose and need for this 

project to provide a diversity of motorized recreation. OHVs (4X4 vehicles, motorcycles, ATVs) are an 

important component of the diversity of motorized recreation. Also, it is not consistent with California 

Vehicle Code or Forest Service policy.

Alternative B: Add All Unauthorized Routes to the System

This alternative would add all existing unauthorized routes to the NFTS. It would also include contingent 

motorized access based on acquiring rights-of-way.

Response: Adding all unauthorized routes to the system does not meet the purpose and need for this 

project to make limited changes to the existing NFTS and identify existing routes for addition to the 

NFTS since it fails to address the criteria contained in 36 CFR Part 212, Subpart B of the Travel 

Management Rule. Also, it is not consistent with the Forest Plan direction for Restricted Motor Vehicle 

Travel Management (TNF LRMP 2007 as amended). Not all unauthorized routes are properly located to 

sustain motorized use and protect resources. The Forest Service does not have the authority to add routes 

to the system without a public right-of-way and current policy does not provide for adding routes 

contingent on future rights-of-way acquisition.

Alternative C: Trigger Seasonal Closure on and off

throughout the Wet Season

This alternative would close native surfaced roads when 1 inch of rain or more fell within a 24-hour time 

period. The roads would remain closed for 48 hours and then re-open. This closure would only occur 

during the wet season, generally November through mid May on the TNF.

Response: Seasonal closures are used to reduce wildlife disturbance; reduce soil compaction during 

wet weather; and, provide for public safety by closing routes during wet winter weather conditions when 

general motorized travel is considered unsafe. This type of triggered closure does not address rain events 

outside of the wet season. It does not respond to wildlife or soil resource protection issues, and it does not 

provide for public safety. In addition, implementation of rainfall based restrictions are not practical for 

many for many reasons including; 1) rainfall amounts vary locally, 2) soil conditions vary depending on 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

34 – Tahoe National Forest

aspect and soil type and 3) difficulty of on-again off-again enforcement. Alternatives 1, 4 and 5 

incorporate this concept to deal with rain events during the proposed season of use.

Alternative D: New Route Construction

This alternative (developed through internal scoping based on public comments) would identify and 

include new route construction to complete loops, connect trails and bypass private property where no 

public right-of-way exists.

Response: New route construction is outside the scope of the purpose and need for this project to 

make limited changes to the existing NFTS and identifying existing routes for addition to the NFTS. New 

trail construction is identified as a potential future project and discussed in the cumulative effects analysis 

in Alternatives 1 and 4.

Alternative E: Non-Motorized

This alternative would prohibit motorized use on the National Forest.

Response: The prohibition of motorized use across the entire National Forest is outside the scope of 

the purpose and need for this project to provide a diversity of motorized recreation and make limited 

changes to the existing NFTS. Also, it is not consistent with Forest Service policy (FSM 7702) which 

states in part: “The objectives of managing the forest transportation system and motor vehicle use on NFS 

roads, on NFS trails, and in areas on NFS lands are: 1. To provide sustainable access in a fiscally 

responsible manner to NFS lands for administration, protection, utilization, and enjoyment of NFS lands 

and resources consistent with the applicable land management plan. 2. To manage the forest 

transportation system and motorized and non-motorized uses on NFS roads, on NFS trails, and in areas on 

NFS lands within the environmental capabilities of the land.”

Alternative F: Grandfather User-Created Routes into the NFTS and 

Conditionally Add Routes Pending Further Analysis and Mitigation

Suggested by the Blue Ribbon Coalition and other advocates of motorized recreation, this alternative 

would consider that many so-called “user-created” routes are actually Forest Service “facilities” since the 

agency expended appropriated funds to place them on previous or current maps or are/were maintained by 

Federal agents. Hence, these facilities are by definition actually system routes and should not be analyzed 

as unauthorized or “user-created” routes. This alternative would also convert “roads-to-single track trails” 

or “roads-to-motorized trails less than 50 inches in width” and “roads managed as motorized trails greater 

than 50 inches in width” to help achieve FS budget objectives while still providing a substantive 

recreational route network. 

Response: Adding all unauthorized routes to the system is not feasible as many do not currently meet 

Forest Plan direction. Even though many of these routes have been in existence for a number of years, 

they were not evaluated for suitability as OHV trails and were not added to the system. They cannot be 

“grandfathered” into the system. Alternative 5 incorporates many of the proposed additions and other 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

Tahoe National Forest – 35

components of this alternative. Also, it is against Forest Service policy to add routes to its transportation 

system that do not have legal access.

Alternative G: Add All Routes Receiving OHV Use

Suggested by the Blue Ribbon Coalition and other advocates of motorized recreation, this alternative 

would designate, at a minimum, all of the system or facility roads and trails receiving current OHV use 

unless the individual route is causing a “considerable adverse affect.” It would designate the maximum 

number of important and historic user-created routes as identified by the public and re-open old existing 

trails that connect to worthwhile destinations. If a considerable adverse effect is found, review for 

mitigation (re-route, maintenance, closure, etc.).

Response: In addition to the Response to Alternative F (above), adding all routes receiving current 

OHV use is not consistent with the Forest Plan direction for Restricted Motor Vehicle Travel Management 

(TNF LRMP 2007 as amended). Some roads were identified in the 2006 OHV inventory as having OHV 

use. These roads previously closed under other NEPA decisions will not be re-opened. Alternative 4 

incorporates some components of this alternative.

Alternative H: Close and Decommission NFTS Roads and Trails

to Reduce Resource Impacts

Suggested by the Wilderness Society and others, this alternative would close and decommission a number 

of roads and trails to reduce road density and disturbance to wildlife; prevent incursions into Wild and 

Scenic River corridors through road closures; reduce access adjacent to Wilderness through road closures; 

not add trails that are in Roadless Areas; implement a seasonal closure for the protection of wildlife; and, 

allow some number of motorized trails to be added to the NFTS.

Response: Decommissioning existing NFTS roads is outside the scope of the purpose and need for 

this project to make limited changes to the existing NFTS. Other resource management considerations are 

necessary to determine whether a route should be decommissioned (e.g. fuel treatment, vegetation

management, fire suppression, special uses, special forest products, etc.) and those activities are outside 

the scope of this decision. Alternative 4 includes some components of this alternative.

Alternative I: Travel Corridors

This alternative (developed through internal scoping based on public comments and developed as part of 

the Proposed Action described in the NOI) would prohibit cross country motor vehicle travel off NFTS 

roads and NFTS trails by the public except to allow vehicle access and parking up to 100 feet off NFTS 

routes for motorized dispersed camping.

Response: Allowing travel corridors on all routes, as an exception to prohibition of cross country

motor vehicle travel, was proposed in the NOI as a way to possibly implement Forest Plan direction. 

Further review of this concept and public comments revealed a necessity to complete a more detailed and 

time consuming site-specific analysis covering thousands of acres where motor vehicles would be 

allowed to travel off NFTS roads. Potential impacts to cultural resources, threatened and endangered 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

36 – Tahoe National Forest

species, wildlife and other resources would need to be analyzed. Based on recent evaluations of the 

timeline, budget and organizational capacity constraints, it is not feasible for the Forest to complete the 

required site-specific analysis needed to implement a travel corridor concept at this time. In its place, the 

Forest developed a strategy to provide access by proposing as many unauthorized recreational access spur 

routes as possible within the limited timeframe to complete this analysis. A limited number of routes were 

inventoried, evaluated and incorporated into Alternatives 1 and 4. Further inventory of recreational access 

routes is ongoing and is not precluded from future consideration in a subsequent NEPA analysis.

Alternative J: Designate Staging Areas in Addition to

Proposed Routes and NFTS Changes

This alternative was developed in response to comments received during scoping from people who would 

like staging areas designated in addition to proposed routes and NFTS changes.

Response: Designation of staging areas is outside the scope of this process. OHV users may stage 

from existing designated roads if they are within about 30 feet of the road. Separate staging areas would 

require construction, signing, and possibly other improvements. If needed in the future, such areas will be 

analyzed and authorized under separate analysis processes.

Alternative K: Allow Cross Country Motorized Use off Designated 

Routes in order to Retrieve Legally Taken Big Game Animals

This alternative was developed in response to comments received during scoping from people who would 

like to utilize motorized vehicles off designated routes to retrieve downed big game.

Response: Allowing motorized off-road travel to any site where an animal is taken means that all 

lands on the Forest would be open to off-road vehicle use (for a specific purpose) during hunting season. 

While the period of use would be limited (+/- 8 weeks for rifle and archery seasons), the resulting impacts 

are considered to be similar to, but less intense than, those that would occur under the No Action 

Alternative. In addition enforcement would be difficult, if not impossible. 

Alternative L: Responsible Recreation Alternative

The Responsible Recreation Alternative would consider the value of historic human experience in the 

forest (including the 1850s). Such an alternative would provide the public with needed access to the 

Tahoe National Forest while meeting the ultimate goal of prohibiting cross country travel. All requested 

trails are currently in use, and user maintained as also demonstrated by the fact they were included in the 

inventory.

Response: The Responsible Recreation Alternative was considered but eliminated from detailed study 

due to its lack of site specificity in any actual proposals or recommendations. There was not sufficient 

substance to this proposal to judge its merits. In addition, the goals and objectives of this alternative were 

incorporated into Alternative 5.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

Tahoe National Forest – 37

Alternative M: Stewards of the Sierra Alternative

Suggested by the Stewards of the Sierra, this alternative addresses issues and resource concerns raised in 

the DEIS. It prohibits cross country use, and meets public motorized access needs.

Response: This alternative was considered but eliminated from detailed study. Each of the site 

specific recommendations contained in this alternative were incorporated into the changes made to the 

Preferred Alternative including additional motorized access opportunities. The rationale for each of the

site specific proposals in this alternative is described in Appendix A (Site Specific Road, Trail and Open 

Area Information) and/or the Project Record.

Comparison of Alternatives _______________________________

This section of Chapter 2 compares the alternatives by summarizing key differences between the 

alternatives and provides a summary of the effects analysis for all alternatives. See Table 2-10 for the 

summary of proposed actions by alternative. See Table 2-11 for the summary comparison of NFTS road 

mileage by class of vehicle and season of use. See Table 2-12 for the summary comparison of NFTS 

motorized trail mileage by class of vehicle and season of use. See Table 2-13 for the criteria for adding 

motorized trails to the NFTS and establishing lands as “Open Areas.”
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

38 – Tahoe National Forest

Table 2-10. Summary of Proposed Actions by Alternative

Action type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

1. Cross Country Travel (Acres) Prohibitions 

continue

81,975 acres

Continues on 

754,066 acres

Prohibited on 

833,392 acres

2,649 acres 

established

open

Prohibited on 

836,000 acres

<100 acres 

established

open

Prohibited on 

836,000 acres

<100 acres 

established

open

Prohibited on 

836,000 acres

<100 acres 

established

open

Prohibited on 

835,800 acres

<300 acres 

established

open

Prohibited on 

836,000 acres

<100 acres 

established

open

2. Additions 

to the NFTS

a. Roads added to the NFTS

(Number of Miles)

(Number of Roads)

0.0

0

5.0

114

0.00

0

3.7

85

5.0

112

13.1

346

0.00

0

b. Motorized Trails added to the 

NFTS

(Number of Miles)

(Number of Trails)

0.0

0

54.6

87

0.0

0

22.6

27

75.4

141

48.3

106

36.7

36

3. Establishment of Motorized “Open Areas” None Greenhorn 

Area (60 

acres) 

Prosser, Boca

and 

Stampede 

Reservoirs 

(2,589 acres)

None None None Prosser, Boca 

and 

Stampede 

Reservoirs 

(244 acres)

None
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

Tahoe National Forest – 39

Action type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

4. Changes 

to the NFTS

a. Change in Class of Vehicles 

resulting from approval of mixed 

use

0.0 241.5 0.0 0.0 241.5 130.8 0.0

b. Change in Class of Vehicles 

resulting from changes in 

maintenance levels

0.0 157.2 0.00 3.4 157.2 122.0 3.4

c. Change in Season of Use 0.0 10.5 0.00 1,312.1 1,396.7 1,369.5 0.00

d. Reopening Maintenance Level 1 

Roads

(Number of Miles)

(Number of Roads) 

0.0

0

0.0

0

0.0

0

0.1

1

93.4

113

11.4

13

1.1

2

5. Amendments to the Forest Plan None Management 

Area 84 

(Humbug 

Sailor) Deer 

Winter Range 

Seasonal 

Restriction 

Removed

None None Management 

Area 84 

(Humbug 

Sailor) Deer 

Winter Range 

Seasonal 

Restriction 

Removed

Management 

Area 84 

(Humbug 

Sailor) Deer 

Winter Range 

Seasonal 

Restriction 

Removed

None
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

40 – Tahoe National Forest

Table 2-11. Summary Comparison of NFTS Road Mileage by Class of vehicle and Season of Use

Class of Vehicle Season of Use Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Roads Open to Highway 

Legal Vehicles Only

Apr. 1 - Sep. 15 5.2 0.0 5.2 5.2 0.0 0.0 5.2

Apr. 1 - Dec. 31 88.1 31.4 88.1 88.1 31.4 59.1 88.1

May 1 - Dec. 31 150.7 29.7 150.7 150.7 29.7 57.9 150.7

May 1 - Nov. 1 21.3 15.8 21.3 21.3 15.8 17.0 21.3

All Year 351.4 141.4 351.4 348.1 141.4 230.2 348.1

Roads Open to All Vehicles Jun. 1 - Nov. 1 3.4 3.4 3.4 3.4 3.4 3.4 3.4

Aug. 1 - Dec. 31 1.2 1.2 1.2 1.2 1.2 1.2 1.2

May 1 - Jun. 15 & 

Jul. 15 - Dec. 31

3.4 3.4 3.4 3.4 3.4 3.4 3.4

Apr. 1 - Sep. 15 0.8 6.0 0.8 0.8 6.0 6.0 0.8

Apr. 1 - Dec. 31 54.9 111.7 54.9 87.4 144.3 798.4 54.9

May 1 - Dec. 31 268.0 389.7 268.0 1,286.2 1,563.4 715.6 268.0

May 1 – Nov. 1 69.9 65.1 69.9 70.1 73.9 63.7 69.9

May 1 – Sep. 15 5.3 5.3 5.3 5.3 5.3 5.3 5.3

All Year 1,044.0 1,268.2 1,044.0 0.0 132.6 4.6 1,048.3

Roads Open to Highway Legal Vehicles Only except 

open to all vehicles during deer season (9/22-11/4)

0.0 0.0 0.0 0.0 0.0 74.2 0.0

Roads Open to Highway Legal Vehicles Only 5/1-9/21;

All vehicles during deer season 9/22-11/4; and 

Highway legal vehicles 11/5-12/31.

0.0 0.0 0.0 0.0 0.0 43.3 0.0

Total NFTS Roads 2,067.6 2,072.6 2,067.6 2,071.3 2,152.0 2,083.4 2,068.5

Note: numbers may not add up due to rounding.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

Tahoe National Forest – 41

Table 2-12. Summary Comparison of NFTS Motorized Trail Mileage by Class of Vehicle and Season of Use

Class of Vehicle Season of Use Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Trails Open to High 

Clearance Trail Vehicles 

(4WD, ATV & Motorcycle)

May 1 – Jun. 15 &

Jul. 15 – Dec. 1

4.4 4.4 4.4 4.4 4.4 4.4 4.4

Apr. 1 – Dec. 31 &

When 15” snow present

0.0 0.0 0.0 0.0 0.0 3.5 0.0

Apr. 1 – Dec. 31 4.8 4.8 4.8 5.1 6.1 88.5 4.8

May 1 – Dec. -31 24.0 32.3 24.0 128.9 166.8 58.9 31.4

May 1 – Nov. 1 1.1 1.1 1.1 1.1 1.1 1.1 1.1

May 1 – Sep. 15 0.0 0.0 0.0 0.0 0.2 0.0 0.0

All Year 99.6 115.5 99.6 0.0 0.0 0.0 109.0

Subtotal 133.9 158.1 133.9 139.5 178.6 156.4 150.7

Trails Open to ATV’s and 

Motorcycles Only

Apr. 1 – Dec. 31 2.2 2.2 2.2 2.2 2.2 34.2 2.2

May 1 – Dec. 31 3.6 4.6 3.6 26.2 41.9 4.6 3.6

All Year 19.6 23.1 19.6 0.0 0.0 0.0 23.1

Subtotal 25.4 29.9 25.4 28.4 44.1 38.8 28.9

Trails Open to Motorcycles 

Only

Apr. 1 – Dec. 31 1.0 1.0 1.0 29.0 40.2 157.8 1.0

May 1 – Dec. 31 18.1 28.0 18.1 150.8 151.4 28.8 24.7

May 1 – Nov. 1 3.3 3.3 3.3 3.3 3.3 3.3 3.3

All Year 146.4 162.5 146.4 0.0 0.0 0.0 156.4

Subtotal 168.8 194.8 168.8 183.1 194.9 189.9 185.4

Total NFTS Trails 328.1 382.8 328.1 351.0 417.6 385.1 365

Note: numbers may not add up due to rounding.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

42 – Tahoe National Forest

Table 2-13. Criteria for additions to the NFTS, re-opening Maintenance Level 1 roads and establishing lands 

as “Open Areas”

Criteria Alt 2 Alt 4 Alt 5 Alt 6 Alt 7

Site specifically recommended by the public during collaboration 

meetings held prior to the NOI

X X X X X

Site specifically recommended by the public during scoping on the 

Proposed Action in the NOI

X X X X X

Consistent with Forest Plan Standards and Guidelines X X X X X

No significant resource concerns which could not be mitigated at 

this time

X X X X X

If access is required across private land, private landowner has not 

expressed opposition to public access

X X X X X

Not closed by a previous Forest Order X X X X X

Not already a NFTS non-motorized trail X X X X X

Not closed or scheduled for decommissioning in a recent NEPA 

decision (last 15 years)

X X X X X

No unacceptable public safety risks X X X X X

Not adverse impacts to Lahontan Cutthroat Trout X X X X X

Does not require new construction or significant re-routing X X X X X

Previous NFTS road still receiving motorized use in the Cal-Ida, 

French Meadows, Mosquito Ridge or Boca/Prosser/ Stampede 

Reservoir areas

X

Trail gradient less than 15% X

Not located within an Inventoried Roadless Area X

No significant impact on Inventoried Roadless Area characteristics X X

Not located within a Citizens Inventoried Roadless Area X

Not located within a proposed or designated Wild & Scenic River X

Provides a high quality off highway vehicle recreation opportunity X

Maintains the “Outstandingly Remarkable Values” of proposed and 

designated Wild & Scenic River

X X X X

Not located within a California Spotted Owl or northern goshawk 

protected activity center (PAC)

X

Not redundant with an existing NFTS road or motorized trail open to 

all vehicles

X

No mitigation measures which could not implemented in a cost 

effective manner

X

No conflicts with an approved mining Plan of Operation X

Does not encourage non-highway legal vehicles to use a road 

designated for highway legal vehicles only

X

Criteria for Alternatives 1 and 3: No motorized roads or trails would be added to the NFTS. No additional lands would be 

established as “Open Areas.”

Table 2-14 below summarizes the effects analysis for all the resources by ranking each alternative 

regarding how well it provides for each of the indicators. The following rankings were used: A score of 7

indicates the alternative has the least impact for the resource related to the indicator. A score of 1 indicates 

the alternative has the greatest adverse impact for the resource. This information is listed at the end of 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

Tahoe National Forest – 43

each resource section in Chapter 3, which describes the environmental consequences of the alternatives in 

detail.

Table 2-14. Comparison Summary of Effects to All Resources across All Alternatives

Indicator Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Air Quality 1 3 7 6 2 4 5

Soil Resources 1.2 2.4 5.4 5.4 3.4 4.0 4.2

Hydrology Resources 1 2 7 6 3 4 5

Terrestrial Species 1 3.6 7 6 2.2 3.2 5

Aquatic Species 1 3.2 7 6 2 3.8 5

Fire and Fuels Management 4 4.5 4 4 4 2.5 5

Heritage Resources 1 2 7 5 4 3 6

Plant Communities 1 3 7 5.8 2 4.4 4.8

Recreation - non-motorized 1 3 7 6 2 4 5

Recreation - motorized 7 4 1 2 6 5 3

Visual Resources 1 4 7 6 2 3 5

Transportation 5.7 3.3 5.3 4 3 3.7 3

Inventoried Roadless & Special Areas 1 3 5 7 2 6 4

Adjacent Ownerships 1 3.5 7 6 2 4 4.5

Society, Culture & Economy 4 4 4 4 4 4 4

Table 2-15 provides a summary comparison of the key environmental effects and outputs for each 

affected resource by alternative. This information is presented in detail in each resource section in 

Chapter 3.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

44 – Tahoe National Forest

Table 2-15. Summary comparison of key environmental outputs and effects for specific resources by 

alternative

Resource Indicator Measure Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Air Quality Amount of Native 

Surface Roads, 

Trails and Areas 

Open to Motorized 

Vehicles (Fugitive 

Dust)

5,293.8 4,053.5 3,595.6 3,625.3 4,167.8 3,803.4 3,636.7

Native Surface 

Roads, Trails on 

Lands “Most 

Likely” to Contain 

Naturally Occurring 

Asbestos

121.0 76.1 67.4 70.3 77.5 73.0 70.9 

Watershed Amount of Native 

Surface Roads by 

Erosion Hazard 

Rating

Very High 287 205 176 176 215 179 177

High 3,896 2,975 2,624 2,649 3,054 2,791 2,657

Moderate 1,042 828 752 759 854 787 758

None 59 42 38 39 42 40 40

Cumulative 

Watershed Effects 

(Equivalent Road 

Acres)

16,030.1 13,253.7 13,179.5 13,205.9 13,446.3 13,275.9 13,219.6 

Terrestrial 

Species

Old Forest 

Emphasis Areas 

within a 200-meter 

Zone of Influence of 

All motorized 

Routes (percent)

55% 39% 38% 38% 40% 39% 38%

Motorized and Nonmotorized Routes 

within Spotted Owl 

Protected Activity 

Centers (miles)

293.5 199.5 195.4 195.4 214.0 199.2 198.6

Aquatic 

Species

Native Surface 

Stream Crossings 

(number of 

crossings)

3,310 2,593 2,462 2,480 2,622 2,580 2,481

Native surface 

routes open to 

motorized use in 

RCA’s (miles)

800 519.3 472.7 480.3 543.7 507.0 481.5

Cultural 

Resources

Cultural resource 

sites potentially 

impacted and/or 

requiring mitigation

(number of sites)

926 110 0 25 104 90 18

Botany 

Resources

Sensitive/watchlist 

species and/or 

watchlist plant 

communities 

located within 0-100 

feet of routes with 

weed occurrences 

within 0-100 feet of 

the route (relative 

amount)

Highest High Lowest Low High Moderate Low
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

Tahoe National Forest – 45

Resource Indicator Measure Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Motorized 

Recreation 

Opportunities 

NFTS Year round 

road and trail 

motorized 

opportunities 

(miles)* 1,661.1 1,710.6 1,661.1 348.1 274.0 234.8 1,684.8

NFTS Seasonal 

road and trail 

motorized 

opportunities 

(miles) 734.7 744.7 734.7 2,074.1 2,295.6 2,233.7 748.8

Sub-Total 2,395.8 2,455.3 2,395.8 2,422.2 2,569.6 2,468.5 2,433.6

“Open Areas” 

(acres)

754,066 2,649 <100 <100 <100 244 <100

Dispersed 

recreation sites 

with motorized 

access (number of 

sites)**

N/A 182 0 107 188 437 29

Nonmotorized 

“Quiet” 

Recreation 

Opportunities

National Forest 

System (NFS) lands 

greater than 1⁄2 mile 

form any motorized 

road or trail 

(percentage of NFS 

lands)

12.2% 16.6% 16.9% 16.8% 16.1% 16.7% 16.6%

Affordability Annual Operation 

and Maintenance 

Cost (millions of 

dollars)

$10.7 $9.3 $10.7 $10.7 $9.4 $9.7 $10.8

Inventoried 

Roadless 

Areas

Total motorized 

roads and trails 

within Inventoried 

Roadless Areas 

(miles)

206.9 156.6 149.0 149.0 160.3 152.6 155.2

Social 

Impacts

Support for the 

lifestyles of 

motorized use 

advocates

Substantial General Little Little General General General

Support for the 

lifestyles of nonmotorized use 

advocates

Little Little General General Little General General

* Alternative 1 includes unauthorized routes and closed NFTS roads still receiving some motorized use

** Under Alternative 1, access to dispersed recreation sites would continue. The number of sites accessed is difficult to determine. 

With continued cross country motorized travel under Alternative 1, access to dispersed recreation sites would be available on lands 

open to cross country motorized travel.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 2: The Alternatives

46 – Tahoe National Forest
Chapter 3 

Affected Environment & 

Environmental Consequences 

Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Tahoe National Forest – 47

Chapter 3: Affected Environment and

Environmental Consequences

Introduction ____________________________________________

This chapter summarizes the physical, biological, social, and economic environments that are affected by 

the proposed action and alternatives (“Affected Environment”) and the effects on that environment that 

would result from implementation of any of the alternatives (“Environmental Consequences”). This 

chapter also presents the scientific and analytical basis for comparison of the alternatives presented in 

“Chapter 2: The Alternatives.” The environmental consequences discussion centers on direct, indirect, and 

cumulative effects, along with applicable mitigation measures. These terms are defined as follows:

• Direct effects are caused by the action and occur at the same place and time as the action.

• Indirect effects are caused by the action and are later in time, or further removed in distance, but 

are still reasonably foreseeable.

• Cumulative effects are those that result from the incremental impact of the action when added to 

other past, present, and reasonably foreseeable future actions.

Analysis Process _______________________________________

The environmental consequences presented in Chapter 3 address the impacts of the actions proposed 

under each alternative for the TNF. This effects analysis was done at the site-specific and forest scales 

(the scale of the proposed action as discussed in Chapter 1). Each affected road, trail, and area proposed 

in the alternatives has been reviewed by resource specialists. These findings are summarized in Appendix 

A (Site Specific Road, Trail and Open Area Information). Readers seeking information concerning the 

environmental effects associated with a specific road, trail, or area are directed to this Appendix, where

details concerning any mitigation measures or any other findings are documented.

For ease of documentation and understanding, the effects of the alternatives are described separately 

for three discrete actions and then combined to provide the total direct and indirect effects of each 

alternative (see below). The combination of the effects of these discrete actions is then added to effects of 

the past, present, and reasonably foreseeable actions in the cumulative effects analysis. The five discrete

actions common to all action alternatives are:

Cross Country Travel: All of the action alternatives prohibit wheeled motor vehicle travel off 

designated NFTS roads, NFTS motorized trails, and areas by the public except as allowed by permit or 

other authorization. Prohibition of cross country travel is included in order to address the need to regulate 

unmanaged motor vehicle use.

Additions to the NFTS: Some action alternatives would add unauthorized routes as roads and trails 

to the NFTS by vehicle class and season of use. Additions are considered in order to respond to the need 

to provide motor vehicle access to dispersed recreation opportunities and to provide a diversity of 

motorized recreation opportunities. For purposes of this analysis, each of these roads and trails is 

identified by a unique number. Resource specialists conducted their site specific review of each proposed 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.00

48 – Tahoe National Forest

route. All road additions have a proposed road management objective (RMO). All proposed additions

would receive the appropriate level of routine maintenance such as brushing, signing, cleaning and 

clearing debris. For some routes, no work beyond routine maintenance would be needed. For others, 

additional mitigation would be needed to bring the route up to a safe and environmentally sustainable 

condition. The specific mitigations must be completed prior to designation of the route on the MVUM for 

public motorized use. All proposed route additions have assigned road or trail management objectives. 

Appendix A shows the specified vehicle class, season of use and mitigations for all proposed route 

additions. Additional details on each route are contained in the Project Record.

Establishment of Motorized “Open Areas”: Some action alternatives would establish motorized 

“Open Areas” by vehicle class and season of use. Establishments are considered in order to respond to the 

need to provide motor vehicle access to dispersed recreation opportunities and to provide a diversity of 

motorized recreation opportunities. For purposes of this analysis, each of these established “Open Areas” 

is identified by name. Resource specialists conducted their site specific review of each proposed “Open 

Area.” All established “Open Areas” would receive the appropriate level of routine maintenance such as 

brushing, signing, cleaning and clearing debris. For some “Open Areas”, no work beyond routine 

maintenance would be needed. For others, additional mitigation is needed to bring the route up to a safe 

and environmentally sustainable condition. The specific mitigations must be completed prior to 

establishment of the “Open Area” on the MVUM for public motorized use. Appendix A shows the 

specified vehicle class, season of use and mitigations for all proposed established “Open Areas.”

Additional details on each “Open Area” are contained in the Project Record.

Changes to the NFTS: Changes to the existing NFTS include Vehicle Class, Season of Use and 

Reopening Maintenance Level 1 roads.

Vehicle class - The action alternatives may include limited changes to the vehicle class allowed on 

existing NFTS roads and/or trails. Vehicle class indicates the type of vehicle (passenger car, 

motorcycle, all-terrain vehicle, etc) allowed to operate on a road or trail. Some alternatives add 

vehicle classes to roads and/or trails where that use is currently prohibited. Some alternatives add 

vehicle classes resulting from changes in maintenance levels. These changes respond to the need 

to provide a diversity of wheeled motorized recreation opportunities and access. 

Season of Use - The action alternatives vary in terms of which roads, trails and areas would have 

motorized travel prohibited during specified times of year. Wet weather seasonal restrictions are 

specified in some of the alternatives to minimize erosion and protect water quality.

Reopening Maintenance Level 1 Roads - Some alternatives include opening Maintenance Level 1 

roads to public use where such use is currently prohibited to enhance motorized recreation 

opportunities. These changes respond to the need to provide a diversity of wheeled motorized 

recreation opportunities and access. Appendix A (Site Specific Road, Trail and Open Area 

Information) shows the specified vehicle class, season of use and mitigations for all proposed 

changes to the existing NFTS.

Amendments to the Forest Plan: Some of the action Alternatives include an amendment to The 

Tahoe National Forest Land and Resource Management Plan (LRMP) to remove the November 1 to May 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.00

Tahoe National Forest – 49

1 seasonal closure in the Sugar Pine area (Management Area 84 Humbug Sailor) on key winter deer range

to improve motorized recreation opportunities.

Cumulative Effects ______________________________________

According to the Council on Environmental Quality (CEQ) NEPA regulations, “cumulative impact” is the 

impact on the environment which results from the incremental impact of the action when added to other 

past, present, and reasonably foreseeable future actions regardless of what agency (Federal or nonFederal) or person undertakes such actions (40 CFR 1508.7).

The cumulative effects analysis area is described under each resource, but in most cases includes the 

entire TNF including private and other public lands that lie within the Forest boundary. Past activities are 

considered part of the existing condition and are discussed in the “Affected Environment (Existing 

Conditions)” and “Environmental Consequences” section under each resource.

In order to understand the contribution of past actions to the cumulative effects of the proposed action 

and alternatives, this analysis relies on current environmental conditions as a proxy for the impacts of past 

actions. This is because existing conditions reflect the aggregate impact of all prior human actions and 

natural events that have affected the environment and might contribute to cumulative effects.

This cumulative effects analysis does not attempt to quantify the effects of past human actions by 

adding up all prior actions on an action-by-action basis. There are several reasons for not taking this 

approach. First, a catalog and analysis of all past actions would be impractical to compile and unduly 

costly to obtain. Current conditions have been impacted by innumerable actions over the last century (and 

beyond), and trying to isolate the individual actions that continue to have residual impacts would be 

nearly impossible. Second, providing the details of past actions on an individual basis would not be useful 

to predict the cumulative effects of the proposed action or alternatives. In fact, focusing on individual 

actions would be less accurate than looking at existing conditions, because there is limited information on 

the environmental impacts of individual past actions, and one can not reasonably identify each and every 

action over the last century that has contributed to current conditions. Additionally, focusing on the 

impacts of past human action risks ignore the important residual effects of past natural events, which may 

contribute to cumulative effects just as much as human action. By looking at current conditions, we are 

sure to capture all the residual effects of past human actions and natural events, regardless of which 

particular action or event contributed those effects. Third, public scoping for this project did not identify 

any public interest or need for detailed information on individual past actions. Finally, the Council on 

Environmental Quality issued an interpretive memorandum on June 24, 2005 regarding analysis of past 

actions, which states, “agencies can conduct an adequate cumulative effects analysis by focusing on the 

current aggregate effects of past actions without delving into the historical details of individual past 

actions.” Past actions are treated similarly in the recently published Forest Service Regulations for 

implementing the National Environmental Policy Act (36 CFR 220). For these reasons, the analysis of 

past actions in this section is based on current environmental conditions.

Appendix H (Reasonably Foreseeable Projects and Cumulative Effects) lists present and reasonably 

foreseeable future actions potentially contributing to cumulative effects. While the appendix lists all 
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Chapter 3: Affected Environment & Environmental Consequences – 3.00

50 – Tahoe National Forest

actions, every resource is not affected by every action. For example, a future project may affect wildlife 

but not affect water quality. Appendix H indicates which resources are potentially affected by each action.

In addition to considering the effects of this proposal on other lands, this EIS considers the likely 

effects on lands administered by the Forest Service from past, ongoing, and reasonably foreseeable 

management actions occurring on other forest lands. Management of other lands could directly affect 

terrestrial and aquatic wildlife species that move between ownerships during the year or during their life 

cycle. The possible contribution of management actions on other lands has been considered in analyzing 

the effects of the alternatives on species and habitats that are not confined to national forests. This 

information is presented in this chapter, which describes likely environmental consequences of the 

alternatives.

Affected Environment Overview ___________________________

There are many aspects of the affected environment that are shared by all resources. In order to avoid 

repeating these shared elements of the affected environment in each resource section, the following 

general elements of the affected environment are provided.

Unmanaged OHV use has resulted in unplanned roads and trails, erosion, watershed and habitat 

degradation, and impacts to cultural resource sites. On some Tahoe National Forest System (NFS) lands, 

long managed as open to cross-country motor vehicle travel, repeated use has resulted in unplanned, 

unauthorized roads and trails. These routes generally developed without environmental analysis or public 

involvement, and do not have the same status as NFTS roads and NFTS trails included in the forest 

transportation system.

On October 26, 2007, a temporary forest order was implemented which prohibited travel off of 

existing routes shown on a forest order exhibit map. The order was established for a period not to exceed 

one year to protect resources and help prevent additional user-created routes from being established while 

the TNF undertook implementation of the Travel Management Rule and the production of their Motor 

Vehicle Use Map (MVUM). This Forest Order was reissued for an additional year on July 13, 2009.

Appendix A (Site Specific Road, Trail and Open Area Information)

Appendix A lists each road, trail and “Open Area” proposed for addition to the NFTS and identifies the 

alternative(s) under which the route is proposed, the type of vehicle(s) allowed, and the season when the 

route would be open. In addition, Appendix A identifies any resource concerns and necessary mitigation 

measures.

Law Enforcement _______________________________________

Law enforcement authority and jurisdiction, cooperation, implementation and tracking, implementation 

strategy, assumptions and measures of success are discussed in detail in Appendix K (Law Enforcement).
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.00

Tahoe National Forest – 51

Law Enforcement Assumptions Common to Effects Analysis:

• Enforcement of the laws and regulations related to Travel Management will be enforced equally 

in authority and weight as with all other Federal laws and regulations.

• As with any change in a regulation on NFS lands, there is usually a transitional period for the 

public to understand the changes. It is anticipated there will be a higher number of violations to 

the Travel Management Rule the first few years and the number of violations will decline as the 

users understand and comply with the rules. 

• Once the motor use vehicle map is published, the implementation of the established dedicated 

network of roads, trails, and areas with signs, and user education programs, will reduce the 

number of violations.

• Providing motorized recreation opportunities in popular, key areas will help relieve pressure to 

travel off of designated routes.

Climate Change_________________________________________

The Environmental Protection Agency (EPA) (2007) developed a “State of Knowledge” paper that 

outlines what is known and what is uncertain about global climate change. The following elements of 

climate change are known with near certainty: 

• Human activities are changing the composition of Earth’s atmosphere. Increasing levels of 

greenhouse gases like carbon dioxide (CO2) in the atmosphere since pre-industrial times are welldocumented and understood. 

• The atmospheric buildup of CO2 and other greenhouse gases is largely the result of human 

activities such as the burning of fossil fuels. 

• An “unequivocal” warming trend of about 1.0 to 1.7 F occurred from 1906-2005. Warming 

occurred in both the Northern and Southern Hemispheres and over the oceans (IPCC, 2007).

• The major greenhouse gases emitted by human activities remain in the atmosphere for periods 

ranging from decades to centuries. It is therefore virtually certain that atmospheric concentrations 

of greenhouse gases will continue to rise over the next few decades. 

• Increasing greenhouse gas concentrations tend to warm the planet. 

According to EPA (2007), however, it is uncertain how much warming will occur, how fast that 

warming will occur, and how the warming will affect the rest of the climate system including 

precipitation patterns. Given what is and is not known about global climate change, the following 

discussion outlines the cumulative effects of this project on greenhouse gas emissions and effects of 

climate change on forest resources. 

Carbon Dioxide (CO2), Methane (CH4) and Nitrous Oxide (N20) emissions generated by public

motorized vehicle travel on NFTS facilities are expected to contribute to the global concentration of 

greenhouse gases that affect climate change. Projected climate change impacts include air temperature 

increases, sea level rise, changes in the timing, location, and quantity of precipitation, and increased 

frequency of extreme weather events such as heat waves, droughts, and floods. The intensity and severity 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.00

52 – Tahoe National Forest

of these effects are expected to vary regionally and even locally, making any discussion of potential sitespecific effects of global climate change on forest resources speculative. 

Because greenhouse gases from vehicle emissions mix readily into the global pool of greenhouse 

gases, it is not currently possible to discern the effects of this project from the effects of all other 

greenhouse gas sources worldwide, nor is it expected that attempting to do so would provide a practical or 

meaningful analysis of project effects. Potential regional and local variability in climate change effects 

add to the uncertainty regarding the actual intensity of this project’s effects on global climate change. 

Further, emissions associated with this project are extremely small in the global atmospheric CO2 context, 

making it impossible to measure the incremental cumulative impact on global climate from emission 

associated with this project. In summary, the potential for cumulative effects is considered negligible for 

all alternatives because none of the alternatives would result in measurable direct and indirect effects on 

air quality or global climatic patterns. 

Short Term Uses and Long Term Productivity ________________

NEPA requires consideration of “the relationship between short-term uses of man’s environment and the 

maintenance and enhancement of long-term productivity” (40 CFR 1502.16). As declared by the 

Congress, this includes using all practicable means and measures, including financial and technical 

assistance, in a manner calculated to foster and promote the general welfare, to create and maintain 

conditions under which man and nature can exist in productive harmony, and fulfill the social, economic, 

and other requirements of present and future generations of Americans (NEPA Section 101).

Alternatives 3, 4, 7, 6, 2 and 5 respectively from most to least, all have the potential to improve the 

long-term productivity by reducing the number of existing routes on the landscape. Routes that are not 

designated for public motor vehicle use will have the potential to revert to vegetated conditions, which 

will reduce many of the adverse effects related to these routes.

Unavoidable Adverse Effects______________________________

Implementation of any of the alternatives would result in some unavoidable adverse environmental 

effects. Although formation of the alternatives included avoidance of some potential adverse effects, some 

adverse effects could occur that cannot be completely mitigated. The environmental consequences section 

for each resource area discusses these effects.

Irreversible and Irretrievable Commitments of Resources ______

Irreversible commitments of resources are those that cannot be regained, such as the extinction of a 

species or the removal of mined ore. Irretrievable commitments are those that are lost for a period of time 

such as the temporary loss of timber productivity in forested areas that are kept clear for use as a power 

line rights-of-way or road.

It is not anticipated that designating, or not designating, some existing NFS and unauthorized routes 

for public motor vehicle use would cause an irreversible or irretrievable commitment of resources.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.00

Tahoe National Forest – 53

Incomplete and Unavailable Information ____________________

The Council on Environmental Quality (CEQ) regulations for implementing the National Environmental 

Policy Act (NEPA) describes how Federal agencies must handle instances where information relevant to 

evaluating reasonably foreseeable adverse impacts of the alternatives is incomplete or unavailable. 

Federal agencies must make clear that such information is lacking, and decide whether this incomplete or 

unavailable information is “essential to a reasoned choice among alternatives” (Title 40 of the Code of 

Federal Regulations, 40 CFR, Part 1502.22). If the information is deemed essential to a reasoned choice 

among the alternatives, it must be included or addressed in the environmental impact statement.

Incomplete or unavailable information is made clear in sections titled Assumptions and Limitations so 

the reader understands how unavailable information was addressed. The EIS summarizes existing credible 

scientific evidence relative to environmental effects and makes estimates of effects on theoretical 

approaches or research methods generally accepted in the scientific community.

Knowledge about the biological, physical, and social aspects of ecosystems is, and always will be, 

incomplete. The ecology, inventory, and management of large landscapes are complex and constantly 

changing. For example, analysis of the impacts of alternatives on specific plant or animal species prompts 

questions about population dynamics and habitat relationships. Key relationships and basic data are well 

established for only a few Tahoe National Forest ecosystems and species. The alternatives were analyzed 

using the best available information. As data gaps were encountered during analysis, the interdisciplinary 

team posed the question of whether the missing information was “essential to a reasoned choice among 

alternatives.” The team concluded that while new information could add precision to estimates or better 

specify relationships; it would be unlikely to significantly change our understanding of the basic 

relationships that were used to analyze the effects of the alternatives. New information is always 

welcome, but no missing information was deemed essential to making a reasoned choice among the 

alternatives being considered in this EIS. In some instances, information was unavailable to confidently 

estimate environmental effects; the text indicates that this information is incomplete or unavailable. In 

such situations, the EIS summarizes existing credible scientific evidence relative to the significant effects 

and makes estimates of effects on theoretical approaches or research methods generally accepted in the 

scientific community.

Other Required Disclosures_______________________________

National Environmental Policy Act of 1969: NEPA at 40 CFR 1502.25(a) directs “to the fullest extent 

possible, agencies shall prepare draft environmental impact statements concurrently with and integrated 

with ...other environmental review laws and executive orders.”

This EIS has been prepared in accordance with the following 

regulations:

National Historic Preservation Act (NHPA) of 1966: Section 106 of the NHPA of 1966 requires federal 

agencies to consider the potential effects of a Preferred Alternative on historic, architectural, or 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.00

54 – Tahoe National Forest

archaeological resources that are eligible for inclusion on the National Register of Historic Places and to 

afford the President’s Advisory Council on Historic Preservation an opportunity to comment. Section 110 

of the Act requires federal agencies to identify, evaluate, inventory, and protect National Register of 

Historic Places resources on properties they control. Potential impacts to archaeological and historic 

resources have been evaluated in compliance with Section 106 of the NHPA.

Executive Order 11644 ORV Management: Executive Order 11644 – Use of Off-Road Vehicles on 

Public Lands (issued February 8, 1972) – provides for the establishment of policies and procedures that 

will ensure that the use of OHVs on public lands will be controlled and directed so as to protect the 

resources of those lands, to promote the safety of all users of those lands, and to minimize conflicts 

among the various uses of those lands. Agency heads are directed to provide for administrative 

designations of the specific areas and trails on public lands on which the use of OHVs may be permitted, 

and areas in which the use of OHVs may not be permitted.

Executive Order 11989 ORV Management: Executive Order 11989 – Use of Off-Road Vehicles on 

Public Lands (issued May 24, 1977) – clarifies agency authority to define zones of use by OHVs on 

public lands. Agency heads, when they determine that the use of OHVs will cause or is causing 

considerable adverse effects on the soil, vegetation, wildlife, wildlife habitat, or cultural or historic 

resources to immediately close such areas or trails to the type of OHV causing such effects, until such 

time that it is determined that such adverse effects have been eliminated and that measures have been 

implemented to prevent further recurrences.

Executive Order 12898 Environmental Justice: Executive Order 12898 – Federal Actions to 

Address Environmental Justice in Minority Populations and Low-Income Populations (issued February 

11, 1994) – requires that each federal agency shall make achieving environmental justice part of its 

mission by identifying and addressing, as appropriate, disproportionately high or adverse human health or 

environmental effects of its programs, policies, and activities on minority populations and low-income

populations. None of the alternatives disproportionately affect minority and low-income populations.

Clean Water Act: The Clean Water Act, as amended, regulates the dredging and filling of freshwater 

and coastal wetlands. Section 404 (33 USC 1344) of the Clean Water Act prohibits the discharge of 

dredged or fill material into waters (including wetlands) of the United States without first obtaining a

permit from the U.S. Army Corps of Engineers. Wetlands are regulated in accordance with federal NonTidal Wetlands Regulations (Sections 401 and 404). No dredging or filling is part of this proposed action 

and no permits are required.

Clean Air Act of 1970: The Clean Air Act of 1970 and its amendments provide for the protection and 

enhancement of the nation’s air resources. No exceeding of the federal and state ambient air quality 

standards is expected to result from any of the alternatives.

Endangered Species Act (ESA) of 1973: The Endangered Species Act of 1973 (16 USC 1531 et 

seq.) requires that any action authorized by a federal agency not be likely to jeopardize the continued 

existence of a threatened or endangered species, or result in the destruction or adverse modification of 

habitat of such species that is determined to be critical. Section 7 of the ESA, as amended, requires the 

responsible federal agency to consult the USFWS and the National Marine Fisheries Service concerning
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Chapter 3: Affected Environment & Environmental Consequences – 3.00

Tahoe National Forest – 55

endangered and threatened species under their jurisdiction. Biological evaluations for Proposed,

Endangered, Threatened, and Sensitive (PETS) species have been prepared for the proposed action and 

informal consultation with the USFWS is ongoing.

National Forest Management Act (NFMA) of 1976: The National Forest Management Act of 1976 

amends the Forest and Rangeland Renewable Resources Planning Act of 1974 and sets forth the 

requirements for Land and Resource Management Plans (Forest Plans) for the National Forest System. 

The alternatives are consistent with the NFMA.
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Chapter 3: Affected Environment & Environmental Consequences – 3.00

56 – Tahoe National Forest
Chapter 3.01 

Air Quality 

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Tahoe National Forest – 57

3.01. Air Quality_________________________________________

The Tahoe National Forest (TNF) Travel Management project is intended to designate routes for public 

motor vehicle use for the TNF, as required by the Travel Management Regulations (36 CFR Part 212, 

Subpart B). The regulations require that each National Forest or Ranger District designate the roads, trails 

and establish “Open Areas” on National Forest System lands that are open to motor vehicles.

This chapter contains an evaluation of how air resources would be affected by implementation of each 

of the alternatives. The chapter contains policy and direction as well as a discussion of the affected 

environment and existing air quality conditions. This chapter describes potential impacts of 

implementation of the different alternatives. Further details are available in the project record.

Regulatory Framework

Direction relevant and specific to the proposed action as it applies to air quality resources includes:

Federal Clean Air Act

The Federal Clean Air Act (CAA) is a federal law passed in 1970, and last amended in 1990, (42 U.S.C. 

§7401 et seq.) which is the basis for national control of air pollution. The CAA was designed to “protect 

and enhance” the quality of the nation’s air resources. Basic elements of the CAA include national 

ambient air quality standards (NAAQS) for criteria air pollutants, technology based emission control 

standards for hazardous air pollutants (HAPs), state attainment plans (SIPs), a comprehensive approach to 

reducing motor vehicle emissions, control standards and permit requirements for stationary air pollution 

sources, acid rain control measures, stratospheric ozone protection and enforcement provisions 

(California Air Resources Board [CARB], 2007).

Regional Haze Rule (1990 Clean Air Act Amendments), 40 CFR Part 51

The Regional Haze Rule requires states to demonstrate “reasonable progress” toward improving visibility 

in each Class I area over a sixty-year period (to 2064), during which visibility should be returned to 

natural conditions. Class I areas include Wilderness Areas or National Parks greater than 5,000 acres 

which existed on August 7, 1977.

General Conformity Rule (1990 Clean Air Act Amendments) (Section 176 (c) of the 

Clean Air Act (part 51, subpart W, and part 93, subpart B.)

The U.S. Environmental Protection Agency (EPA) passed the final General Conformity rule in 1993. 

Under the rule, federal agencies must work with state and local governments in a nonattainment or 

maintenance area to ensure that federal actions conform to the initiatives established in the applicable 

state implementation plan (U.S. EPA, 2008). A project is non-conforming if it conflicts with or delays 

implementation of any applicable attainment or maintenance plan. The rule divides the conformity 

process into two phases: applicability and determination.

California Clean Air Act (H&S §§ 39660 et seq.)

California adopted the California Clean Air Act (CCAA) in 1988. The Act provides the basis for air 

quality planning and regulation in California independent of federal regulations, and establishes ambient 
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Chapter 3: Affected Environment & Environmental Consequences – 3.01. Air Quality

58 – Tahoe National Forest

air quality standards for the same criteria pollutants as the federal clean air legislation (CARB, 2007).

Under the Federal CAA, States can adopt air quality standards that are more stringent than the Federal 

NAAQS. California has chosen to adopt standards for criteria pollutants that are generally more 

restrictive than Federal standards. The California Air Resources Board (CARB) is the agency responsible 

for establishing California ambient air quality standards (CAAQs), setting vehicle emission standards and 

fuel specifications and regulating emissions from certain types of mobile equipment and consumer 

products.

CARB Off-Road Recreational Vehicle Emissions Standards Rulemaking

In 1994, the CARB approved new off-highway recreational vehicle regulations (since amended in 1998).

This rulemaking established emission standards for off-highway vehicles (OHVs) including off-road 

motorcycles (dirt bikes) and all-terrain vehicles (ATVs) (CARBc, 2006). OHV registration became 

contingent on vehicle compliance to California emission standards. Dirt bikes and ATVs that meet 

emission standards are eligible for OHV Green Sticker registration and have a year-round operating 

period, while noncompliant vehicles fall under the OHV Red Sticker program which may have a limited 

operational season, depending upon the location.

Affected Environment

Introduction

The two primary potential impacts to air quality resulting from the Travel Management Project are: 1) Air 

Pollution and 2) Naturally Occurring Asbestos.

Air Pollution

The climate, geography and population growth within and/or adjacent to the Tahoe National Forest (TNF)

are the major reasons that air pollution is an issue on the TNF. The mountains on the TNF encircle cities 

and create conditions where air and pollution are trapped. Therefore, the pollution created by population 

growth and its supporting infrastructure in those cities is often trapped near the TNF. Sunlight triggers 

chemical reactions that lead to secondary pollutants and haze commonly known as “smog.”

Radiative transfer, atmospheric transport and dispersion, and chemical reactions play major roles in 

creating high concentrations of ozone in the Sierra Nevada. Nitrogen Oxides (NO2) and Volatile Organic 

Compounds (VOCs), precursors to ozone, are emitted by mobile sources and carried by wind from the 

Bay Area, Sacramento and the Central Valley to the western slopes of the TNF. During the transport 

process the precursors react to form ozone in the presence of sunlight. Other aerosols (e.g., ammonia, 

nitrates, sulfates, pesticides, herbicides and fine particulates) are also carried by wind. These are deposited 

on vegetation (dry deposition) or brought down in rain, clouds, fog or mist (wet deposition generally 

called acid rain) affecting vegetation. This polluted air coming from outside the forest can impact the 

forest’s flora, fauna, watersheds, and surrounding communities. Forest management activities also 

generate pollutants that can affect forest resources, as well as surrounding communities, for example 

smoke from prescribed burning.
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Chapter 3: Affected Environment & Environmental Consequences – 3.01. Air Quality

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Visibility is also impacted by pollutants. Visibility impairment results from both the scattering and 

absorption of light by particles and gases in the air. Fine particles less than 2.5 microns in diameter 

(PM2.5) are especially efficient at scattering light. Fine elemental carbon particles (soot) and nitrogen 

dioxide gas are the typical absorbers of light. Scattering by “air” molecules (primarily oxygen and 

nitrogen with a diameter less than 0.0001 microns) causes the sky to appear blue and, in the absence of 

natural particulates, sets the upper limit visibility in a specific geographic region.

Affected Air Basins and Air Pollution Control Districts: California is divided into 14 geographic 

air basins. An air basin is an area surrounded by topographic features that provide for common air quality 

and transport. The California Air Resources Board (CARB) maintains air quality data by air basin. The 

TNF is located within the Mountain Counties air basin.

The State is directly responsible for regulating emissions from mobile sources. However, authority to 

regulate stationary sources has been delegated to Air Pollution Control and Air Quality Management 

Districts (APCDs and AQMDs) within the provisions of the CCAA and oversight by the California 

Environmental Protection Agency. Figure 3.01-1 shows air basins and Air Pollution Control Districts.
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60 – Tahoe National Forest

Figure 3.01-1. California Air Basins/Counties and Air Pollution Control Districts
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Chapter 3: Affected Environment & Environmental Consequences – 3.01. Air Quality

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Pollutants of Concern: The primary air pollutants, that can cause detrimental effects to public health 

and/or native ecosystems, are produced in part by motorized vehicle use and include particulates, sulfur 

compounds, nitrogen compounds, ozone, and carbon oxides.

• Particulates: The term “particulate” is used to describe dispersed solid and liquid airborne 

particles that are suspended in the atmosphere for a period of time. Particulate matter includes 

dust, dirt, soot, smoke and liquid droplets directly emitted into the air by sources such as factories, 

power plants, vehicles, construction activity, fires and natural windblown dust. Particles formed in 

the atmosphere, such as sulfur dioxide (SO2) and VOCs are also considered particulate matter. 

They can contribute to visibility impairment and human health problems. Particulate matter less 

than 10 microns in diameter (PM10) are those which can enter the human respiratory system.

Motorized vehicles produce particulates that are primarily referred to as fugitive dust. Fugitive 

dust is particulate matter suspended in the air. Fugitive dust can cover vegetation reducing the 

amount of photosynthesis (refer to Chapter 3.06, Plant Communities).

• Sulfur Compounds: Sulfur compounds (oxides, sulfuric acid, and sulfates) are present in the air 

naturally as a result of seasalt, biogenic gases, and volcanic emissions. Globally, human industrial 

emissions have almost doubled the amount of sulfur inputs to air compared to pre-industrial levels.

Deposition of sulfur compounds can cause acidification of water and soils, decrease visibility, and 

affect such life forms as cryptogams (such as fungi, algae, mosses, and ferns). Some of the sulfur 

in diesel fuel is converted to sulfate particles in motorized vehicle exhaust.

• Nitrogen Compounds: The primary releases of nitrogen compounds (oxides, ammonium, and 

nitrates) naturally to the air are from microbial activity, lightning and wildfires. The historical 

levels of nitrogen compounds in the air have almost doubled on a global basis as a result of fossil 

fuel combustion, animal husbandry practices, and fertilization. Nitrogen compounds can 

negatively affect aquatic systems, can affect visibility, and are a precursor compound to ozone, 

which is toxic to plants. Motorized vehicles emit nitrogen oxides in their exhaust. A 1991 EPA 

report showed that non-road engines (lawn and garden equipment, farm and construction 

equipment, recreational vehicles, marine vessels, and airport service equipment) had total 

emissions almost as high as highway motor vehicles. Non-road emissions from diesel engines 

were significantly higher than highway emissions in this 1991 study.

• Ozone: Ozone is formed when emissions of VOCs combine with nitrogen compounds in the 

presence of sunlight and warm temperatures. It is naturally present in small quantities; however, 

amounts have increased substantially due to increased levels of nitrogen compounds and VOCs.

Ozone is a major component of smog and affects human health. It has been suggested as a factor 

contributing to the decline of sensitive forest tree species in the Sierra Nevada, and has been 

shown to cause injurious effects to both Jeffrey and ponderosa pine.

• Carbon Oxides: Carbon monoxide (CO) and carbon dioxide (CO2) are produced by natural and 

human sources. CO is a poisonous gas produced by incomplete burning of carbon in fuels. CO2 is 

natural constituent of the troposphere (lowest level of the atmosphere). It has a role in global 
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climate change, making it a significant pollutant. Motorized vehicles emit carbon monoxide in 

their exhaust.

Sources of Pollutants: Air pollutants affecting the health of TNF resources can result from natural or 

human processes. Natural air pollution may occur from forest fires, decomposition of plants and animals, 

soil erosion, pollen and mold spores, VOCs emitted by vegetation, electrical storms and photochemical 

reactions. Human caused air pollution sources include: industrial sources, prescribed wildland burning, 

animal production, agricultural burning, residential and business development, and vehicle emissions.

Emissions from National Forest Activities: Forest activities that generate air pollutants include 

prescribed burns, recreation use, vehicle traffic, site preparation, mining, livestock and pack animals, and 

vegetation management. This analysis focuses on those air pollutants generated from motorized vehicle 

use.

The growing popularity of motorized vehicles has led to concerns about impacts to air quality. 

Motorized vehicle engines can be either two-stroke or four-stroke. It is estimated that 60-65 percent of the 

motorcycles used off highways (in the United States) have two-stroke engines (EPA 2001 in Kassar 

2005). Between 10-15 percent of ATVs in the United States use two-stroke engines (ibid). Two stroke 

engines are less fuel efficient and emit more unburned hydrocarbons (HC) and particulate matter (PM) 

than four-stroke engines. The EPA estimates that 25-30 percent of the fuel in a two-stroke engine remains 

unburned and is released into the air and water. Emissions from engines include carbon monoxide, 

hydrocarbons, particulate matter, and a variety of gases classified as “air toxins” such as formaldehyde, 

other related aldehydes, and VOCs such as benzene. Motorcycles with two-stroke engines have been 

found to release ten times the amount of HC emissions as four-stroke motorcycles (CARB 2001 in Kassar 

2005). The emissions released by two-stroke engine motorcycles are considered responsible for 90 

percent of the emissions from OHVs that contribute to the formation of smog in California (ibid).

As mentioned above, ozone is formed when emissions of VOCs combine with nitrogen compounds in 

the presence of sunlight and warm temperatures. Many of the off-road vehicles registered in California 

emit 50 times more pollution than a current model passenger car reflecting their lack of regulation in the 

past and designs that emphasize performance over fuel economy (CARB 1997 in Kassar 2005). Some 

estimates state that off-road vehicles produce as much as 4000 times more carbon monoxide emissions 

and 118 times as many smog-forming pollutants as modern automobiles on a per-mile basis (CARB 1998 

in Kassar 2005).

Off-road diesel-powered equipment is considered highly polluting. Diesel is one of the largest 

contributors to environmental pollution problems worldwide (Lloyd and Cackette 2001). Atmospheric 

deposition of air pollutants released from diesel exhaust is considered a significant source of ecosystem 

contamination (ibid). In addition, heavy metals and dioxins common to diesel exhaust can be transported 

long distances as gases or PM. EMFAC2000, California’s emissions inventory model, estimated that even 

though diesel-powered vehicles contribute only 5 percent of the daily vehicle miles of travel in California, 

these diesel-powered vehicles produced at least 56 percent of the vehicle exhaust particulate matter in 
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California in the year 2000. However, there is no new data available on the particulate matter after 

October 2006, when all diesel fuels were required to switch to low sulfur.

Fugitive Dust, PM10 and PM2.5: Motorized vehicle use of native surface roads/trails/areas also has 

the potential to create fugitive dust and increase PM10 and PM2.5 concentrations. The amount of fugitive 

dust, PM10 and PM2.5 concentrations generated by motorized vehicles using native surface roads/trails/

areas is dependent on many factors including the type of vehicle, vehicle speed, and number of vehicles.

Exposure to high concentrations of engine emissions and fugitive dust can negatively affect human 

health, damage vegetation; negatively impact animals, reduce soil health and water quality, have 

atmospheric effects, and affect visibility. A summary of possible impacts follows:

• Effects to Human Health: High concentrations of particles can affect human health by: making it 

difficult to breath, aggravating existing respiratory and cardiovascular disease, reducing the body’s 

defense systems against foreign materials, damaging lung tissue, and contributing to the 

development of cancer and premature death. The major subgroups of the population most sensitive 

to the effects of particulate matter are individuals with chronic obstructive pulmonary or 

cardiovascular disease or influenza, asthmatics, the elderly and children.

• Effects on Vegetation: Visible impacts to plants from motorized vehicle emissions include:

changes in leaf structure such as chlorophyll destruction (chlorosis), tissue death (necrosis), and 

pigment formation. Damage may occur even when no visible injury is apparent. Such effects can 

include reductions in photosynthesis, growth reduction, and predisposition to attack by insects.

• Effects on Animals: Animal health is at risk when animals are exposed to high levels of air 

pollutants via inhalation of gases or small particles, ingestion of particles suspended in food or 

water, and absorption of gases through the skin. In general, only soft bodied invertebrates (for 

example, earth worms), or animals with thin, moist skin (for example, amphibians) are affected by 

dermal absorption of pollutants.

• Effects on Soil and Water: Chemicals from motorized vehicle engines (such as SO2 and NO2) can 

be washed into the soil by low-pH rainwater. The soil then neutralizes much of the acidity by 

dissolving and mobilizing minerals. These minerals such as aluminum, calcium, magnesium, 

sodium and potassium may then be leached from the soil into surface waters. The ability of soil to 

tolerate this acidic deposition is very dependent on the alkalinity of the soil. Many of the steep 

slopes on the TNF are covered by shallow soils with relatively limited neutralizing capacity.

Watersheds with steep slopes with shallow soils and acid rain have lakes and streams that are 

susceptible to low pH and high levels of aluminum. This combination has been found to be toxic 

to some fish species. Our ability to predict the effects of air pollution on aquatic systems is limited 

by the lack of deposition monitoring sites across the range of ecological conditions in the TNF.

• Atmospheric Effects: The atmosphere serves as a sink for pollutants and has a considerable 

capacity for self-renewal. However, the atmosphere is susceptible to short and/or long-term 

pollution-induced changes. Atmospheric changes can include reduced visibility, changes to urban 

climate/frequency of rainfall/precipitation chemistry, changes in stratosphere ozone levels, and 

global climate changes.
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Current Conditions

Area Designations (Attainment vs. Non-Attainment Area): State and federal agencies have established 

ambient air quality standards for criteria pollutants. If the permissible levels of a particular pollutant are 

not exceeded in an area, the area is said to be in attainment for that pollutant; if the standards are violated, 

the area is designated as non-attainment. Table 3.01-1 shows the designation for the affected counties in 

the TNF. None of the counties are in non-attainment for federal PM10 standards and only Placer County is 

in non-attainment for federal ozone standards. All counties are in non-attainment for state PM10 standards.

Table 3.01-1. Area Designation for State and Federal Standards for PM10 and Ozone

County PM10 PM2.5 Ozone

Federal State Federal Federal State

Nevada (eastern) U N A U/A N

Nevada (western) U N A N N

Placer A N A U/A T

Plumas U N A A U

Sierra U N A U/A U

Yuba A N A A N

Note: A – Attainment; N – Non-attainment; T – Transitional; and U – Unclassified

Visibility: Visibility conditions in the Sierra Nevada improve from south to north and also from low 

elevation to high elevations. In general terms, the visibility conditions on the TNF are considered good.

The TNF is located within a class II airshed.

Ozone: The amounts of ozone on the TNF have increased substantially as a result of increased levels 

of nitrogen compounds and volatile organic compounds. A Pacific Southwest Regional ozone study

confirms injurious effects to both the Jeffrey and ponderosa pines. Ozone production varies significantly 

with changing atmospheric conditions. Models are not available to predict ozone formation resulting from 

motorized vehicle emissions. Instead, emissions of ozone precursors (NO2 and VOCs) are usually 

modeled to help predict the effects. Relative contributions to ozone production can be estimated based on 

quantity of ozone precursors emitted and climatic conditions at the time of the emissions.

Sulfur and Nitrogen Compounds: The amount of Sulfur compounds that are being released into the 

air are considered very low (SNFPA 2001). However, the amount of Nitrogen (N) compounds in the air 

has increased (ibid). Levels of wet and dry N deposition in the Sierra Nevada are still considered well 

below saturation levels in the northern forests (ibid).

Interaction among Sulfur and Nitrogen compounds and ozone: The three primary pollutants that 

interact at a broad scale across the TNF and have been demonstrated to impact terrestrial systems include 

sulfur dioxide, nitrogen oxides, and ozone. Many native plant species, particularly ponderosa pine and a 

host of lichens and mosses are susceptible to increasing levels of ozone. In addition, high-elevation plant 

communities are at substantial risk to ozone effects while low-elevation native plant communities may be 

affected by elevated nitrogen levels. Most plant communities adjacent to urban areas are or would be 
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Tahoe National Forest – 65

affected by nitrogen compounds, ozone and sulfur compounds. The TNF has a higher risk of ozone 

damage due to it’s proximity to major pollution centers and the prevailing air currents.

Naturally Occurring Asbestos (NOA)

Introduction: Asbestos is a term used for several types of naturally-occurring fibrous minerals found in 

many parts of California. The most common type of asbestos is chrysotile, but other types are also found 

in California. Serpentine rock often contains chrysotile asbestos. Serpentine rock, and its parent material, 

ultramafic rock, are abundant in the TNF. Serpentine rock is typically grayish-green to bluish-black in 

color and may have a shiny appearance.

Asbestos is commonly found in ultramafic rock, including serpentine, and near fault zones. The 

amount of asbestos that is typically present in these rocks ranges from less than 1percent up to about 25

percent, and sometimes more. Asbestos is released from ultramafic and serpentine rock when it is broken 

or crushed. This can happen when motor vehicles drive over native surface roads that contain these rocks.

It is also released naturally through weathering and erosion. Once released from the rock, asbestos can 

become airborne and may stay in the air for long periods of time.

Background on Naturally Occurring Asbestos: “Asbestos” is a commercial term used to identify a 

group of six silicate minerals (chrysotile, crocidolite, amosite, tremolite, actinolite, anthophyllite) of 

fibrous or asbestiform habit, which have the properties of high tensile strength, flexibility, chemical 

resistance, and heat resistance. These properties have made these minerals useful in many manufactured 

products and industrial processes during the Twentieth Century. A few examples of the many uses of 

asbestos include brake and clutch linings, insulation, fireproof textiles, and filtration products. The use of 

asbestos in manufactured goods and processes in the United States has significantly decreased over the 

last 30 years because of health concerns related to asbestos exposure.

“Naturally Occurring Asbestos” (NOA) is the term applied to the natural geologic occurrence of any 

of the six types of asbestos. The presence of asbestos in nature is related to the chemistry of rocks in an 

area and the different geologic processes that have acted on those rocks through time. Formation of 

asbestos requires certain chemical conditions (available silica, magnesium, calcium, iron, sodium and 

water) and physical conditions (appropriate temperature, pressure, and possibly stress). These conditions 

may be present in a variety of geologic settings, but are more common in some settings than in others. In 

addition to the six asbestos minerals listed above, other asbestiform amphiboles such as richterite and 

winchite are known or suspected of posing a health risk (Wylie and Verkouteren, 2000). Further 

discussion of the mineralogy and geology of asbestos can be found in Clinkenbeard and others (2002).

Location of Areas “Most Likely” to contain Naturally Occurring Asbestos on The TNF: To 

evaluate the geology of the TNF and the likelihood of the presence of NOA, information on geologic 

units and soils units was reviewed. The locations most likely to contain NOA are distributed principally in 

the Foresthill region. Their distribution in the TNF is shown in Figure 3.01-2.

Soils derived from asbestos-bearing rocks may contain free asbestos (asbestos fibers broken down to 

the size they could become airborne and inhaled by humans). Soils derived from ultramafic rocks and 

serpentinite commonly are distinctive; they often are identified in soils studies as serpentine- or 
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66 – Tahoe National Forest

ultramafic- related soils. Typically, they are found as linear belts along major fault zones in the western 

part of the Forest. The areas represent a composite of both the areas of ultramafic rocks and serpentinite 

and the areas of soil derived from these rocks.

Serpentinite and partially serpentinized ultramafic rocks often can contain chrysotile asbestos. These 

rocks may also host amphibole asbestos, typically tremolite, actinolite, or anthophyllite. Also, soils 

derived from weathering of ultramafic rocks and serpentinite may contain NOA. Soil maps include the

following ultramafic- and serpentinite related soils series: Dubakella and Forbes.

Figure 3.01-2. Areas “Most Likely” to Contain Naturally Occurring Asbestos

Potential Human Effects: Motorized vehicle users on native surface roads and trails with NOA may 

have increased potential risks for adverse effects to their health. Asbestos is classified as a known human 

carcinogen by state, federal, and international agencies. State and federal health officials consider all 

types of asbestos to be hazardous. Information on the health effects of asbestos can be found in the 

Toxicological Profile for Asbestos by the Agency for Toxic Substances and Disease Control (2001). Table 

3.01-2 displays the current area available for motor vehicle use on lands “most likely” to contain naturally 

occurring asbestos.
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Table 3.01-2. Motor vehicle use on native surface roads, trails and areas “most likely” to contain naturally 

occurring asbestos

Category Amount

Cross Country Travel

Unauthorized routes and closed NFTS roads still receiving some motorized use (miles)

Area (acres )

53.6

1,660

NFTS Roads (miles) 26.4 

NFTS Trails (miles) 42.8

Private roads 24.6

Environmental Consequences

Air Pollution

Emissions: Predictions about changes in total amount of emissions (sulfur compounds, nitrogen 

compounds and carbon oxides) generated from motorized recreational use that may occur on the Forest 

are difficult to make and would be highly speculative. The Forest Service believes that under all 

alternatives, levels of emissions (other than fugitive dust) from motorized recreation use would increase 

by the same amount based on population growth in the market area. Although the use patterns may 

change, it is expected that total visitation, and hence emissions, would increase by the same amount in all 

alternatives. For example, even though the overall number of available motorized roads and trails is 

reduced in all of the action alternatives, the same levels of use would occur and simply become more 

concentrated in those areas. Therefore, the amount of pollutants other than fugitive dust is anticipated to 

increase by the same amount in all alternatives.

It is acknowledged that there are many unknowns regarding future regulations on emissions from 

non-road engines (lawn and garden equipment, farm and construction equipment, recreational vehicles, 

marine vessels, and airport service equipment). New standards to reduce hydrocarbon (HC) emissions 

from gasoline powered non-road recreational vehicles were adopted by EPA in 2002. These new emission 

standards for new gasoline-powered recreational non-road vehicles were phased in beginning in 2006. 

EPA expects these standards to reduce HC emissions from these vehicles by 67 percent and CO emissions 

by 28 percent – nationally – over time. EPA expects that manufacturers would primarily increase their use 

of 4-stroke engine system designs and improve materials and barrier treatments to reduce the permeation 

of gasoline through fuel tanks and hoses.

Since EPA has shown that non-road equipment (lawn and garden equipment, farm and construction 

equipment, recreational vehicles, marine vessels, and airport service equipment) emits large amounts of

nitrogen oxides as well as HC and CO, it is likely that regulations would be developed to reduce the 

amounts of nitrogen oxides produced from recreational gasoline powered vehicles also. New non-road 

diesel engines already have emission standards designed to reduce nitrous oxide emissions (EPA 2003). 

However, current regulations still allow the sale of non-complying OHVs with two-stroke engines found 

on most non-compliant OHVs (CARB 2007). Table 3.01-3 shows average emissions in tons/day for 
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68 – Tahoe National Forest

Placer, Nevada and Sierra Counties within the Mountain Counties Air Basin. It is unknown if these 

emissions would go up or down over time.

Table 3.01-3. 2006 Estimated Annual Average Emissions for Off-Road Recreational Vehicles (tons per day)

Area TOG ROG CO NO2 SO2 PM PM10

Statewide 70.54 66.18 184.19 2.04 .57 .83 .75

Sierra County 2.10 1.96 4.75 .05 .02 .03 .02

Nevada County 1.45 1.36 3.24 .03 .01 .02 .02

Placer County 1.98 1.85 4.16 .04 .02 .03 .02

Note: TOG - Total organic gases; ROG - Reactive organic gas; CO - Carbon monoxide; NO2 - Nitrogen oxides; and SO2 - Sulfur 

oxides.

Ozone: As mentioned previously the western Nevada County portion of the TNF is in federal nonattainment for ozone. Motorized vehicle use does not generate significant amounts of ozone precursors 

and if generated these ozone precursors are generally below de minimis (so small or minimal in difference 

that it does not matter or the law does not take it into consideration) and are thus exempt from conformity 

determination. This statement is based on a 1991 non-road and vehicle emission study done by EPA and 

SNFPA 2001 air quality modeling. The emissions of ozone precursors (NO2 and VOCs) are expected to 

increase over time with levels of wet and dry nitrogen deposition in the Sierra Nevada also increasing. 

However, levels are still below saturation levels in the northern forests (SNFPA 2001) and non-road 

recreational vehicles are not considered a significant source of ozone precursors at this time. New 

emission regulations would further reduce contributions from non-road vehicles in the future.

Fugitive Dust (Particulate Matter): To assess the air quality effects from fugitive dust, the 

alternatives are compared by the number of miles of native surface (dirt) motorized roads, trails and areas 

available for use. Those alternatives with the greatest amount of native surface roads, trails and areas have 

the greatest potential to release fugitive dust (particulate matter) into the air. The amount and timing of the 

motorized vehicle use and the type of motorized vehicle recreating on each road/trail/area is unknown.

Other unknown factors that contribute to the amount of fugitive dust produced include: the weather at the 

time of use and the condition of the road/trail/area, etc.

Fugitive dust from unpaved roads/trails/areas can add suspended particles into the air especially 

during summer use when the soils are dry. There is currently no way to know exactly how much 

particulate matter is being generated on the TNF through use of motorized vehicles or to speculate how 

much would be produced by alternative in the future. Therefore, it is assumed that the alternatives that 

provide the greatest number of miles available for use by motorized vehicles have the greatest potential 

for producing fugitive dust. Refer to Table 3.01-4.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.01. Air Quality

Tahoe National Forest – 69

Table 3.01-4. Amount of Native Surface Roads, Trails and Areas Open to Motorized Vehicles

Action type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

1. Cross country travel (acres) Prohibitions 

continue

81,975 

acres

Continues 

on 754,066

acres

Prohibited 

on 833,392 

acres

2,649 

acres 

established 

open

Prohibited 

on 836,000 

acres

<100 acres 

established

open

Prohibited 

on 836,000 

acres

<100 acres 

established

open

Prohibited 

on 836,000 

acres

<100 acres 

established

open

Prohibited 

on 835,800 

acres

<300 acres 

established

open

Prohibited 

on 836,000 

acres

<100 acres 

established

open

2. Additions 

to the NFTS

a. Roads added to the NFTS 0.0 5.0 0.0 3.7 5.0 13.1 0.0

b. Motorized Trails added to the NFTS 0.0 54.6 0.0 22.6 75.4 48.3 36.7

3. Establishment of Motorized “Open Areas” (acres) 0 2,649 0 0 0 244 0

4. Changes 

to the NFTS

a. Change in Class of Vehicles resulting 

from approval of mixed use

No Effect

b. Change in Class of Vehicles resulting 

from changes in maintenance levels

0.0 157.2 0.00 3.4 157.2 122.0 3.4

c. Change in Season of Use No Effect

d. Reopening Maintenance Level 1 Roads 0.0 0.0 0.0 0.1 93.4 11.4 1.1

5. Amendments to the Forest Plan No Effect

Total Miles*

Total Acres

5,293.8

754,066

4,053.5

2,649

3,595.6

0

3,625.3

0

4,167.8

0

3,803.4

244

3,636.7

0

*Includes State, County and private roads. Alternative 1 includes unauthorized routes and closed NFTS roads still receiving some motorized use.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.01. Air Quality

70 – Tahoe National Forest

Alternative 1 poses the greatest risk of impacts to air quality due to the continuation of cross country 

travel on 754,066 acres including 1,698.3 miles of native surface roads and trails unauthorized for 

motorized use. All of the action alternatives reduce the potential risks to air quality by prohibiting cross 

country travel and reducing the amount of native surface roads and trails available for motorized travel.

It is anticipated that implementation of Alternative 1 would have the highest potential risk for 

producing fugitive dust. Implementation of Alternative 1 could potentially contribute to air quality 

degradation more than any of the action alternatives. All of the action alternatives could potentially

improve air quality.

Alternative 1

Cross Country Travel: Cross country travel would not be prohibited in Alternative 1. Predicting where 

cross country motorized vehicle use would occur is not possible. It is likely that this cross country travel 

would damage and/or kill some vegetation and increase the amount of bare soil. Cross country travel also 

results in the continued use of 754,066 acres resulting in approximately 1,700 miles of unauthorized

routes and closed NFTS roads on native surfaces. This use could contribute to increased air quality 

degradation.

Additions to the NFTS: There are no additions of any native surface roads or motorized trails to the 

NFTS in Alternative 1. Since there are no additions, there would be no potential adverse impacts on air 

quality from this element.

Establishment of Motorized “Open Areas”: “Open Areas” would not be established in Alternative 

1and would therefore have no potential adverse impacts to air quality from this element.

Changes to the NFTS: There are no changes to the NFTS in this alternative.

Amendments to the Forest Plan: There are no amendments to the Forest Plan in this alternative.

Cumulative Effects: By not prohibiting cross country travel, motorized use would continue on 

754,066 acres resulting in 5,293.8 miles of native surface roads and trails. The proliferation of additional 

unauthorized native surface roads and trails by motor vehicles would continue.

Alternative 2

Cross Country Travel: Cross country travel would be prohibited in Alternative 2. This would stop the 

proliferation of new unauthorized routes with native surfaces. The prohibition of cross country travel also 

results in reducing use of all unauthorized roads, trails and areas not added to the NFTS. These changes 

could have a positive effect on air quality conditions.

Additions to the NFTS: Alternative 2 would add an additional 5 miles of roads and 54.6 miles of 

motorized trails on native surface soils to the NFTS. These additional roads and motorized trails have the 

potential to produce fugitive dust and thus contribute to air quality degradation.

Establishment of Motorized “Open Areas”: Four areas totaling 2,649 acres would be established as 

“Open Areas.” These additional established “Open Areas” could increase the potential for fugitive dust 

and have an adverse impact on ambient air quality.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.01. Air Quality

Tahoe National Forest – 71

Changes to the NFTS: Approval of mixed use and changing season of use on NFTS roads and trails 

would have no effect on ambient air quality. Changing maintenance levels on 157.2 miles of NFTS roads 

would result in an increased mileage of native surface roads and could have potential adverse effects on 

ambient air quality. No changes in seasonal restrictions are proposed. No Maintenance Level 1 roads 

would be reopened, and therefore no increased risk of fugitive dust.

Amendments to the Forest Plan: The Forest Plan Amendment of removing the Deer Winter Range 

Seasonal Restrictions in Management Area 84 would not increase the potential for fugitive dust and 

therefore would have no effect on ambient air quality.

Cumulative Effects: Alternative 2 potentially improves air quality by reducing the amount of acreage 

open to motorized vehicle use on native surfaces from 754,066 acres to 2,649. It also reduces the total 

number of native surface roads and trails available for motorized use from 5,293.8 to 4,053.5 miles.

Alternative 3

Cross Country Travel: Cross country travel would be prohibited in Alternative 3. This would stop the 

proliferation of new unauthorized routes with native surfaces. The prohibition of cross country travel also 

results in reducing use of all unauthorized roads, trails and areas not added to the NFTS. These changes 

could have a positive effect on air quality conditions.

Additions to the NFTS: There are no additions to the NFTS in Alternative 3. Since there are no 

additions, there would be no potential adverse impacts on air quality from this element.

Establishment of Motorized “Open Areas”: “Open Areas” would not be established in Alternative 3 

and would therefore have no potential adverse impacts to air quality from this element.

Changes to the NFTS: There are no changes to the NFTS in this alternative.

Amendments to the Forest Plan: There are no amendments to the Forest Plan in this alternative

Cumulative Effects: Alternative 3 potentially improves air quality by reducing the amount of acreage 

open to motorized vehicle use on native surfaces from 754,066 acres to less than 100. It also reduces the 

total number of native surface roads and trails available for motorized use from 5,293.8 to 3,595.6 miles.

Alternative 4

Cross Country Travel: Cross country travel would be prohibited in Alternative 4. This would stop the 

proliferation of new unauthorized routes with native surfaces. The prohibition of cross country travel also 

results in reducing use of all unauthorized roads, trails and areas not added to the NFTS. These changes 

could have a positive effect on air quality conditions.

Additions to the NFTS: Alternative 4 would add an additional 3.7 miles of roads and 22.6 miles of 

motorized trails on native surface soils to the NFTS. These additional roads and motorized trails have the 

potential to produce fugitive dust and thus contribute to air quality degradation.

Establishment of Motorized “Open Areas”: “Open Areas” would not be established in Alternative 4 

and would therefore have no potential adverse impacts to air quality from this element.

Changes to the NFTS: Approval of mixed use and changing season of use on NFTS roads and trails 

would have no effect on ambient air quality. Changing maintenance levels on 3.4 miles of NFTS roads 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.01. Air Quality

72 – Tahoe National Forest

would result in an increased mileage of native surface roads and could have potential adverse effects on 

ambient air quality. Wet weather seasonal restrictions would be applied to all native surface roads and 

motorized trails. This change might slightly improve air quality conditions by reducing emissions from 

vehicles during the winter months. The wet weather seasonal restrictions would have no benefit in terms 

of the amount of fugitive dust produced on native surface roads and trails during the dry season. One 

Maintenance Level 1 road at 0.1 mile would be reopened with a minimal increased risk of fugitive dust.

Amendments to the Forest Plan: There are no amendments to the Forest Plan in this alternative.

Cumulative Effects: Alternative 4 potentially improves air quality by reducing the amount of acreage 

open to motorized vehicle use on native surfaces from 754,066 acres to less than 100. It also reduces the 

total number of native surface roads and trails available for motorized use from 5,293.8 to 3,625.3 miles.

Alternative 5

Cross Country Travel: Cross country travel would be prohibited in Alternative 5. This would stop the 

proliferation of new unauthorized routes with native surfaces. The prohibition of cross country travel also 

results in reducing use of all unauthorized roads, trails and areas not added to the NFTS. These changes 

could have a positive effect on air quality conditions.

Additions to the NFTS: Alternative 5 would add an additional 5 miles of roads and 75.4 miles of 

motorized trails on native surface soils to the NFTS. These additional roads and motorized trails have the 

potential to produce fugitive dust and thus contribute to air quality degradation.

Establishment of Motorized “Open Areas”: “Open Areas” would not be established in Alternative 5 

and would therefore have no potential adverse impacts to air quality from this element.

Changes to the NFTS: Approval of mixed use and changing season of use on NFTS roads and trails 

would have no effect on ambient air quality. Changing maintenance levels on 157.2 miles of NFTS roads 

would result in increased mileage of native surface roads available for motorized use and could have 

potential adverse effects on ambient air quality. Wet weather seasonal restrictions would be applied to all 

native surface roads and motorized trails. This change might slightly improve air quality conditions in 

terms of emissions from vehicles during the winter months. The wet weather seasonal restrictions would

have no benefit in terms of the amount of fugitive dust produced on native surface roads and trails during 

the dry season. About 93 miles of Maintenance Level 1 roads would be reopened, and could result in an 

increased risk of fugitive dust.

Amendments to Forest Plan: The Forest Plan Amendment of removing the Deer Winter Ranger 

Seasonal Restrictions in Management Area 84 would not increase the potential for fugitive dust and 

therefore would have no effect on ambient air quality.

Cumulative Effects: Alternative 5 potentially improves air quality by reducing the amount of acreage 

open to motorized vehicle use on native surfaces from 754,066 acres to less than 300. It also reduces the 

total number of native surface roads and trails available for motorized use from 5,293.8 to 4,167.8 miles.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.01. Air Quality

Tahoe National Forest – 73

Alternative 6

Cross Country Travel: Cross country travel would be prohibited in Alternative 6. This would stop the 

proliferation of new unauthorized routes with native surfaces. The prohibition of cross country travel also 

results in reducing use of all unauthorized roads, trails and areas not added to the NFTS. These changes 

could have a positive effect on air quality conditions.

Additions to the NFTS: Alternative 6 would add an additional 13.1 miles of roads and 48.3 miles of 

motorized trails on native surface soils to the NFTS. These additional roads and motorized trails have the 

potential to produce fugitive dust and thus contribute to air quality degradation.

Establishment of Motorized “Open Areas”: Four new areas totaling 244 acres would be established

as “Open Areas.” These additional designated “Open Areas” could increase the potential for fugitive dust 

and have an adverse impact on ambient air quality. 

Changes to the NFTS: Approval of mixed use and changing the season of use on NFTS roads and 

trails would have no effect on ambient air quality. Changing maintenance levels on 122.0 miles of NFTS 

roads would result in an increased mileage of native surface roads available for motorized use and could 

have potential adverse effects on ambient air quality. Wet weather seasonal restrictions would be applied 

to all native surface roads and motorized trails. This change may have a slight improvement on air quality 

conditions by reducing emissions from vehicles during the winter months. The wet weather seasonal 

restrictions would have no benefit in terms of the amount of fugitive dust produced on native surface 

roads and trails during the dry season. A total of 11.4 miles of Maintenance Level 1 roads would be 

reopened, and could result in an increased risk of fugitive dust.

Amendments to Forest Plan: The Forest Plan Amendment of removing the Deer Winter Range 

Seasonal Restrictions in Management Area 84 would not increase the potential for fugitive dust and 

therefore would have no effect on ambient air quality.

Cumulative Effects: Alternative 6 potentially improves air quality by reducing the amount of acreage 

open to motorized vehicle use on native surfaces from 754,066 acres to less than 300. It also reduces the 

total number of native surface roads and trails available for motorized use from 5,293.8 to 3,803.4 miles.

Alternative 7

Cross Country Travel: Cross country travel would be prohibited in Alternative 7. This would stop the 

proliferation of new unauthorized routes with native surfaces. The prohibition of cross country travel also 

results in reducing use of all unauthorized roads, trails and areas not added to the NFTS. These changes 

could have a positive effect on air quality conditions.

Additions to the NFTS: Alternative 7 would add an additional 36.7 miles of motorized trails on 

native surface soils to the NFTS. These additional motorized trails have the potential to produce fugitive 

dust and thus contribute to air quality degradation.

Establishment of Motorized “Open Areas”: “Open Areas” would not be established in Alternative 7 

and would therefore have no potential adverse impacts to air quality from this element.

Changes to the NFTS: Approval of mixed use and changing season of use on NFTS roads and trails 

would have no effect on ambient air quality. Changing maintenance levels on 3.4 miles of NFTS roads 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.01. Air Quality

74 – Tahoe National Forest

would result in an increased mileage of native surface roads available for motorized use and could have 

potential adverse effects on ambient air quality. A total of 1.1 miles of Maintenance Level 1 roads would 

be reopened, and could result in minor increase in risk of fugitive dust.

Amendments to the Forest Plan: There are no amendments to the Forest Plan in this alternative.

Cumulative Effects: Alternative 7 potentially improves air quality by reducing the amount of acreage 

open to motorized vehicle use on native surfaces from 754,066 acres to less than 100. It also reduces the 

total number of native surface roads and trails available for motorized use from 5,293.8 to 3,636.7 miles.

Naturally Occurring Asbestos

Motorized vehicle users on native surface roads and trails with Naturally Occurring Asbestos (NOA) may 

have increased potential risks for adverse effects to their health. Asbestos is classified as a known human 

carcinogen by state, federal, and international agencies. Table 3.01-5 displays the area available for motor 

vehicle use on lands “most likely” to contain naturally occurring asbestos by alternative. Each of these 

routes was tested under the "Guidelines for Geologic Investigations of Naturally Occurring Asbestos in 

California" and; 1) it was determined there was no significant risks of human exposure to airborne 

asbestos or 2) the route will be encapsulated to assure there are no significant risks of human exposure to 

airborne asbestos prior to the route being opened to public motorized use see Appendix A (Site Specific 

Road, Trail and Open Area Information).
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.01. Air Quality

Tahoe National Forest – 75

Table 3.01-5. Native Surface Roads, Trails and Areas Open to Motorized Vehicles on Lands “Most Likely” to 

Contain Naturally Occurring Asbestos

Action type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

1. Cross country travel : Unauthorized routes and 

closed NFTS roads still receiving some motorized 

use (miles)

(acres)

53.6

1,660

0

0

0

0

0

0

0

0

0

0

0

0

2. Additions 

to the NFTS

a. Roads added to the NFTS 0.0 0.1 0.0 0.0 0.1 0.1 0.0

b. Motorized Trails added to the 

NFTS

0 3.9 0.0 2.9 4.1 3.3 3.5

3. Establishment of Motorized “Open Areas”

(acres)

0 0 0 0 0 0 0

4. Changes 

to the NFTS

a. Change in Class of Vehicles 

resulting from approval of mixed 

use

b. Change in Class of Vehicles No Effect

resulting from changes in 

maintenance levels

c. Change in Season of Use

d. Reopening Maintenance Level 1 

Roads 

0 0.0 0.0 0.0 1.2 0.3 0.0

5. Amendments to the Forest Plan No Effect

Total Miles*

Total Acres

121.0

1,660

76.1

0

67.4

0

70.3

0

77.5

0

73.0

0

70.9

0

*Includes State, County and private roads. Alternative 1 includes unauthorized routes and closed NFTS roads still receiving some 

motorized use.

Alternative 1 poses the greatest potential risk of human exposure to airborne asbestos due to the 

continuation of country travel on 1,660 acres that are “Most Likely” to contain naturally occurring 

asbestos. This includes 53.6 miles of unauthorized routes and closed NFTS roads still receiving some 

motorized use. All of the action alternatives reduce the potential human exposure to asbestos by 

prohibiting cross country travel and use of those unauthorized routes not being added to the NFTS. 

Alternative 1

Cross Country Travel: Cross country travel would not be prohibited in Alternative 1. Predicting where 

cross country motorized vehicle use would occur is not possible. It is likely that this cross country travel 

would include travel on lands “Most Likely” to contain naturally occurring asbestos. Cross country travel 

also results in the continued unauthorized use of approximately 53.6 miles of native surface routes “Most 

Likely” to contain naturally occurring asbestos. This use would contribute to an increased risk of human 

exposure to naturally occurring asbestos.

Additions to the NFTS: There are no additions to the NFTS in Alternative 1. Since there are no 

additions, there would be no increased risks to asbestos exposure from this element.

Establishment of Motorized “Open Areas”: This alternative would not establish any new motorized 

“Open Areas.”
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.01. Air Quality

76 – Tahoe National Forest

Changes to the NFTS: There are no proposed changes to the NFTS in this alternative.

Amendments to the Forest Plan: There are no amendments to the Forest Plan in this alternative.

Cumulative Effects: Alternative 1 poses the greatest potential risk of human exposure to airborne 

asbestos due to the continuation of cross country travel on 1,660 acres that are “Most Likely” to contain 

naturally occurring asbestos. This includes 53.6 miles of unauthorized routes and closed NFTS roads still 

receiving some motorized use.

Alternative 2

Cross Country Travel: Cross country travel would be prohibited in Alternative 2. This would stop the 

proliferation of new unauthorized routes in areas “Most Likely” to contain naturally occurring asbestos. 

The cross country travel ban also results in reducing the use of all unauthorized routes not added to the 

NFTS located on these lands. These changes would reduce the risk of human exposure to airborne 

asbestos.

Additions to the NFTS: Alternative 2 would add an additional 4 miles of native surface roads and 

trails to the NFTS on land “Most Likely” to contain naturally occurring asbestos. These routes have 

mitigation measures specified in Appendix A (Site Specific Road, Trail and Open Area Information) to 

assure there are no significant risks to human health prior to being opened to public motorized use.

Establishment of Motorized “Open Areas”: This alternative would not establish any new motorized 

“Open Areas” on lands most likely to contain naturally occurring asbestos.

Changes to the NFTS: Changing the class of vehicles or season of use on existing NFTS roads and 

motorized trails would have no effect on risks to human health associated with exposure to airborne 

asbestos. Alternative 2 would not reopen any Maintenance Level 1 roads on lands “Most Likely” to 

contain naturally occurring asbestos.

Amendments to the Forest Plan: The Forest Plan Amendment would have no impact on the 

potential risk of human exposure to airborne asbestos.

Cumulative Effects: Alternative 2 reduces the risk of human exposure to airborne asbestos by 

prohibiting cross country travel on 1,660 acres and reducing the total amount of native surface roads and 

trails available for motorized vehicles from 121.0 to 76.1 miles on lands “Most Likely” to contain 

naturally occurring asbestos. 

Alternative 3

Cross Country Travel: Cross country travel would be prohibited in Alternative 3. This would stop the 

proliferation of new unauthorized routes on areas “Most Likely” to contain naturally occurring asbestos. 

The cross country travel ban also results in reducing use of all unauthorized routes not added to the NFTS

located on these lands. These changes would reduce the risk of human exposure to airborne asbestos.

Additions to the NFTS: Alternative 3 would not add additional miles of native surface trails to the 

NFTS on land “Most Likely” to contain naturally occurring asbestos. Implementation of Alternative 3

would not increase the potential risk of human exposure to asbestos.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.01. Air Quality

Tahoe National Forest – 77

Establishment of Motorized “Open Areas”: This alternative would not establish any new motorized 

“Open Areas.”

Changes to the NFTS: There are no proposed changes to the NFTS in this alternative.

Amendments to the Forest Plan: There are no amendments to the Forest Plan in this alternative.

Cumulative Effects: Alternative 3 reduces the risk of human exposure to airborne asbestos by 

prohibiting cross country travel on 1,660 acres and reducing the total amount of native surface roads and 

trails available for motorized vehicles from 121.0 to 67.4 miles on lands “Most Likely” to contain 

naturally occurring asbestos. 

Alternative 4

Cross Country Travel: Cross country travel would be prohibited in Alternative 4. This would stop the 

proliferation of new unauthorized routes on areas “Most Likely” to contain naturally occurring asbestos. 

The cross country travel ban also results in reducing use of all unauthorized routes not added to the NFTS

located on these lands. These changes would reduce the risk of human exposure to airborne asbestos.

Additions to the NFTS: Alternative 4 would add an additional 2.9 miles of native surface roads and 

trails to the NFTS on land “Most Likely” to contain naturally occurring asbestos. These routes have 

mitigation measures specified in Appendix A (Site Specific Road, Trail and Open Area Information) to 

assure there are no significant risks to human health prior to being opened to public motorized use.

Establishment of Motorized “Open Areas”: This alternative would not establish any new motorized 

“Open Areas.”

Changes to the NFTS: Changing the class of vehicles or season of use on existing NFTS roads 

would have no effect on risks to human health associated with exposure to airborne asbestos. Alternative 

4 would not reopen any Maintenance Level 1 roads on lands “Most Likely” to contain naturally occurring 

asbestos.

Amendments to the Forest Plan: There are no amendments to the Forest Plan in this alternative.

Cumulative Effects: Alternative 4 reduces the risk of human exposure to airborne asbestos by 

prohibiting cross country travel on 1,660 acres and reducing the total amount of native surface roads and 

trails available for motorized vehicles from 121.0 to 70.3 miles on lands “Most Likely” to contain 

naturally occurring asbestos. 

Alternative 5

Cross Country Travel: Cross country travel would be prohibited in Alternative 5. This would stop the 

proliferation of new unauthorized routes on areas “Most Likely” to contain naturally occurring asbestos. 

The cross country travel ban also results in reducing use of all unauthorized routes not added to the NFTS

located on these lands. These changes would reduce the risk of human exposure to airborne asbestos.

Additions to the NFTS: Alternative 5 would add an additional 4.2 miles of native surface roads and 

trails to the NFTS on land “Most Likely” to contain naturally occurring asbestos. These routes have 

mitigation measures specified in Appendix A (Site Specific Road, Trail and Open Area Information) to 

assure there are no significant risks to human health prior to being opened to public motorized use.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.01. Air Quality

78 – Tahoe National Forest

Establishment of Motorized “Open Areas”: This alternative would not establish any new motorized 

“Open Areas.”

Changes to the NFTS: Changing the class of vehicles or season of use on existing NFTS roads 

would have no effect on risks to human health associated with exposure to airborne asbestos. Alternative 

5 would reopen 1.2 miles Maintenance Level 1 roads on lands “Most Likely” to contain naturally 

occurring asbestos. These routes have mitigation measures specified in Appendix A (Site Specific Road, 

Trail and Open Area Information) to assure there are no significant risks to human health prior to being 

opened to public motorized use.

Amendments to the Forest Plan: The Forest Plan Amendment would have no impact on the 

potential risk of human exposure to airborne asbestos.

Cumulative Effects: Alternative 5 reduces the risk of human exposure to airborne asbestos by 

prohibiting cross country travel on 1,660 acres and reducing the total amount of native surface roads and 

trails available for motorized vehicles from 121.0 to 77.5 miles on lands “Most Likely” to contain 

naturally occurring asbestos. 

Alternative 6

Cross Country Travel: Cross country travel would be prohibited in Alternative 6. This would stop the 

proliferation of new unauthorized routes on areas “Most Likely” to contain naturally occurring asbestos. 

The cross country travel ban also results in reducing use of all unauthorized routes not added to the NFTS

located on these lands. These changes would reduce the risk of human exposure to airborne asbestos.

Additions to the NFTS: Alternative 6 would add an additional 3.4 miles of native surface roads and 

trails to the NFTS on land “Most Likely” to contain naturally occurring asbestos. These routes have 

mitigation measures specified in Appendix A (Site Specific Road, Trail and Open Area Information) to 

assure there are no significant risks to human health prior to being opened to public motorized use.

Establishment of Motorized “Open Areas”: This alternative would not establish any new motorized 

“Open Areas” on lands “Most Likely” to contain naturally occurring asbestos.

Changes to the NFTS: Changing the class of vehicles or season of use on existing NFTS roads 

would have no effect on risks to human health associated with exposure to airborne asbestos. Alternative 

6 would reopen .3 miles Maintenance Level 1 roads on lands “Most Likely” to contain naturally occurring 

asbestos. These routes have mitigation measures specified in Appendix A (Site Specific Road, Trail and 

Open Area Information) to assure there are no significant risks to human health prior to being opened to 

public motorized use.

Amendments to the Forest Plan: The Forest Plan Amendment would have no impact on the 

potential risk of human exposure to airborne asbestos.

Cumulative Effects: Alternative 6 reduces the risk of human exposure to airborne asbestos by 

prohibiting cross country travel on 1,660 acres and reducing the total amount of native surface roads and 

trails available for motorized vehicles from 121.0 to 73.0 miles on lands “Most Likely” to contain 

naturally occurring asbestos. 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.01. Air Quality

Tahoe National Forest – 79

Alternative 7

Cross Country Travel: Cross country travel would be prohibited in Alternative 7. This would stop the 

proliferation of new unauthorized routes on areas “Most Likely” to contain naturally occurring asbestos. 

The cross country travel ban also results in reducing use of all unauthorized routes not added to the NFTS

located on these lands. These changes would reduce the risk of human exposure to airborne asbestos.

Additions to the NFTS: Alternative 7 would add an additional 3.5 miles of native surface roads and 

trails to the NFTS on land “Most Likely” to contain naturally occurring asbestos. These routes have 

mitigation measures specified in Appendix A (Site Specific Road, Trail and Open Area Information) to 

assure there are no significant risks to human health prior to being opened to public motorized use.

Establishment of Motorized “Open Areas”: This alternative would not establish any new motorized 

“Open Areas.”

Changes to the NFTS: Changing the class of vehicles or season of use on existing NFTS roads 

would have no effect on risks to human health associated with exposure to airborne asbestos. Alternative 

7 would not reopen any Maintenance Level 1 roads on lands “Most Likely” to contain naturally occurring 

asbestos.

Amendments to the Forest Plan: There are no amendments to the Forest Plan in this alternative.

Cumulative Effects: Alternative 7 reduces the risk of human exposure to airborne asbestos by 

prohibiting cross country travel on 1,660 acres and reducing the total amount of native surface roads and 

trails available for motorized vehicles from 121.0 to 70.9 miles on lands “Most Likely” to contain 

naturally occurring asbestos.

Summary of Effects Analysis across All Alternatives

The following table 3.01-6 summarizes the effects analysis for air quality by ranking each alternative 

regarding how well it provides for each of the indicators. The following rankings were used: A score of 7

indicates the alternative has the least impact for air quality related to the indicator. A score of 1 indicates 

the alternative has the greatest adverse impact for air quality. This information is to be used to fill out the 

alternatives summary at the end of Chapter 2 of the EIS.

Table 3.01-6. Comparison of Effects to Air Quality

Indicator Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Amount of Native Surface Roads, Trails and Areas 

Open to Motorized Vehicles

1 3 7 6 2 4 5

Native Surface Roads, Trails and Areas Open to 

Motorized Vehicles on Lands “Most Likely” to 

Contain Naturally Occurring Asbestos

1 3 7 6 2 4 5

Average 1 3 7 6 2 4 5
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Chapter 3: Affected Environment & Environmental Consequences – 3.01. Air Quality

80 – Tahoe National Forest
Chapter 3.02 

Watershed Resources: 

Geology, Soil, Hydrology 

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Tahoe National Forest – 81

3.02. Watershed Resources: Geology, Soil, Hydrology_________

Introduction

This section discusses the physical aspects of watershed resources: geology, soil, and hydrology. The 

biological and botanical aspects of watershed resources are discussed in Section 3.03 (Terrestrial and 

Aquatic Species) and 3.06 (Plant Communities). Several attributes of watershed resources can be 

impacted by management activities: soil hydrologic function and erosion rates and the amount and rate of 

sedimentation, stream flow (quantity, timing, and quality), and flooding; (Kattelmann and Dozier 1991). 

However, the relative importance of the alterations and the ability of natural and human communities to 

adapt to or recover from alterations in hydrologic processes in the Sierra Nevada are highly dependent 

upon the degree, extent, and location of change and the sensitivity of the watershed.

Forest management activities, including development of geologic resources, can result in ecosystem 

damage when the activity’s location, construction, or implementation is not based on an understanding of 

geologic conditions and geomorphic processes. The protection of soil and water quantity and quality are

important parts of the mission of the Forest Service (Forest Service Strategic Plan for 2007 to 2012, July 

2007). Management activities on National Forest System lands must be planned and implemented to 

protect the health of forest soils and watersheds, including the productivity and hydrologic functions of 

soils and the volume, timing, and quality of streamflow. The use of roads, trails, and “Open Areas” on 

National Forests for the operation of motor vehicles has the potential to affect these hydrologic functions 

through the compaction of soils; interception of runoff; and detachment, transport, and deposition of 

sediment (e.g., Foltz, 2006). Management decisions to prohibit cross country travel, add new motorized 

trails to the National Forest Transportation System (NFTS), establish “Open Areas, and/or make changes 

to the existing vehicle class and season of use on the National Forest Transportation System (NFTS) must 

consider effects on soil and watershed functions. Information in this analysis has been summarized at a 

variety of scales, including: forest level, river basin, the Hydrologic Unit Code 6 (HUC6) scale 

(watershed approximately 10,000 to 40,000 acres in size), the Hydrologic Unit Code 7 (HUC 7) scale 

(watersheds approximately 2,500 to 10,000 acres in size), and site specifically by individual route. The 

HUC7 watershed is the scale usually used for cumulative watershed effects for projects on the TNF.

Land Ownership Patterns

Land ownership patterns can influence watershed effects analysis. Some HUC7 watersheds within the 

boundaries of the Tahoe National Forest are managed primarily by the Forest Service, some are mixed 

National Forest System lands and private ownership, and others are primarily under private ownership. It 

is difficult to show the direct and indirect effects of this proposal in watersheds with a high percentage of 

private ownership. For example, the Donner Lake HUC7 watershed is 74 percent privately owned. There 

are 369 native surface, motorized stream crossings in this watershed. Of these 369 crossings, only 36 are 

under Forest Service jurisdiction. Given that the Forest Service only owns ten percent of the crossings, 

any changes in this watershed associated with proposals in this document would be masked by the 

impacts associated with those on private land. However, this document analyzes the cumulative effects of 

activities on all lands regardless of ownership.
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82 – Tahoe National Forest

Most National Forest System (NFS) lands have roads and motorized trails that are not under Forest 

Service control (federal, state and county routes). For example, Figure 3.02-1 shows road and trail density 

by HUC7 watershed for the No Action Alternative and two of the action alternatives. In each alternative 

the first set of bars is total motorized road and trail density all ownerships and the second set is National 

Forest Transportation System (NFTS) motorized road and trail density. In every case the percent of HUC7 

watersheds with road and trail density less than 2.5 miles per square mile is highest when looking only at 

NFTS motorized road and trail density. NFTS motorized road and trail density in excess of 5.5 miles per 

square mile occurs only in Alternative 1. All action alternatives would decrease the density of motorized 

roads and trails on NFS lands below 5.5 miles per square mile at the HUC7 watershed scale.

Figure 3.02-1. Total Route Density and Forest Service Route Density for Alternatives 1, 2 and 5

Geology _______________________________________________

Introduction: Geological resources affect all aspects of National Forest System lands. Geological 

resources include cave resources, paleontological resources, geological special interest areas, and ground 

water resources. Geological hazards can impact public safety on NFS lands. Hazards can include mine 

shafts, rock falls, debris flows, slope stability issues, caves and public health concerns. Geology 

determines watershed morphology, soils types, and other essential ecosystem functions. Ground water is a 

valuable resource that may be affected by this project. Mining related hazards are a concern for public 

safety as the National Forests could have potentially dangerous abandoned mine shafts and hazardous 

products in the areas of the proposed action.

0%

10%

20%

30%

40%

50%

60%

70%

alt 1 alt 1 fs alt 2 alt 2 fs alt 5 alt 5 fs

Motorized Road/Trail Density by Alt Total and Land Ownership

Percent of HUC7 Watersheds on TNF

0-2.5

2.6-3.5

3.6-4.5

4.5-5.5

>5.5
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Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

Tahoe National Forest – 83

Regulatory Framework

Regulatory Direction relevant to the proposed action as it affects geologic resources includes:

FSM-2880.11 - Statutory Authority

• Organic Administrative Act of June 4, 1897, as Amended (30 Stat. 34, as Supplemented and 

Amended; 16 U.S.C. 473-478, 482-482(a), 551. (FSM 2501.1.) This act authorizes the Secretary 

of Agriculture to issue rules and regulations for the occupancy and use of the National Forests.

This is the basic authority for issuing special use permits for the collection of vertebrate 

paleontological resources for scientific and educational purposes on National Forest System lands.

• Preservation of American Antiquities Act of June 8, 1906 (34 Stat. 225; 16 U.S.C. 431 et seq.).

(FSM 2361.01.) This act authorizes permits for archeological and paleontological exploration 

involving excavation, removal, and storage of objects of antiquity or permits necessary for 

investigative work requiring site disturbance or sampling which results in the collection of such 

objects.

• Federal Aid Highway Act (72 Stat. 913; 23 U.S.C. 305). This section of the United States Code 

allows federal funding for mitigation of archeological and paleontological resources recovered 

pursuant to Federal aid highway projects. 

• Multiple Use - Sustained Yield Act of June 12, 1960 (MUSY) (74 Stat. 215; 16 U.S.C. 528-

531). (FSM 2501.1.) This act requires due consideration for the relative values of all resources and 

implies that the administration of nonrenewable resources must be considered. 

• Watershed Protection and Flood Prevention Act of August 4, 1954, as Amended (68 Stat. 

666; 16 U.S.C. 1001). (FSM 2501.1.) This act authorizes the Secretary of Agriculture to share 

costs with other agencies in recreational development, ground-water recharge, and water-quality 

management, as well as the conservation and proper use of land. 

• Federal Water Pollution Control Act of July 9, 1956, as Amended (33 U.S.C. 1151) (FSM 

2501.1); Federal Water Pollution Control Act Amendments of 1972 (86 Stat. 816) (FSM 

2501.1), and Clean Water Act of 1977 (91 Stat. 1566; 33 U.S.C. 1251). (FSM 2501.1, 7440.1.)

These acts are intended to enhance the quality and value of the water resource and to establish a 

national policy for the prevention, control, and abatement of water pollution. Ground water 

information, including that concerning recharge and discharge areas, and information on geologic 

conditions that affect ground water quality are needed to carry out purposes of these acts.

• Wilderness Act of September 3, 1964 (78 Stat. 890; 16 U.S.C. 1131-1136). (FSM 2501.1.) This 

act describes a wilderness as an area which may also contain ecological, geological, or other 

features of scientific, educational, scenic, or historical value. These geological features are 

generally identified for wilderness classification purposes.

• National Forest Roads and Trails Systems Act of October 13, 1964 (78 Stat. 1089; 16 U.S.C. 

532-538). (FSM 7701.1.) This act provides for the construction and maintenance of an adequate 

system of roads and trails to meet the demands for timber, recreation, and other uses. It further 

provides that protection, development, and management of lands will be under the principles of 
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Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

84 – Tahoe National Forest

multiple use and sustained yield of product and services (16 U.S.C. 532). Geologic conditions 

influence the final selection of route locations. 

• Wild and Scenic Rivers Act of October 2, 1968 (82 Stat. 906 as Amended; 16 U.S.C. 1271-

1287). This act states that it is the policy of the United States that certain selected rivers of the 

Nation which, with their immediate environments, possess outstanding scenic, recreation, 

geologic, fish and wildlife, cultural, or other similar values shall be preserved in free-flowing 

condition.

• National Environmental Policy Act of January 1, 1970 (NEPA) (83 Stat. 852 as Amended; 42 

U.S.C. 4321, 4331-4335, 4341-4347). (FSM 1950.2.) This act directs all agencies of the Federal 

Government to utilize a systematic interdisciplinary approach which will ensure the integrated use 

of the natural and social sciences in planning and in decision making which may have an impact 

on man’s environment. Geology is one of the applicable sciences. 

• Mining and Minerals Policy Act of December 31, 1970 (84 Stat. 1876; 30 U.S.C. 21a). This act 

provides for the study and development of methods for the disposal, control, and reclamation of 

mineral waste products and the reclamation of mined lands. This requires an evaluation of geology 

as it relates to ground water protection and geologic stability.

• Endangered Species Act of 1973 (ESA) (87 Stat. 884, as amended; 16 U.S.C. 1531-1536, 1538-

1540). This act provides for the conservation of endangered and threatened species and their 

habitats.

• Archeological and Historical Conservation Act of 1974 (AHCA) (88 Stat. 174; 16 U.S.C. 469).

(FSM 2361.01.) This act requires all Federal agencies to notify the Secretary of the Interior when 

a construction project threatens to irreparably harm or destroy significant scientific, prehistoric, 

historic, or archeological data. The paleontological resource may have significant scientific and 

historic value.

• Disaster Relief Act of 1974 (88 Stat. 143; 42 U.S.C. 5121, 5132). Section 202(b) states that the 

President shall direct appropriate Federal agencies to ensure timely and effective disaster 

warnings for such hazards as earthquakes, volcanic eruptions, landslides, and mudslides.

The Federal Register, Vol. 42, No. 70 of April 12, 1977, “Warnings and Preparedness for Geologic 

Related Hazards,” implies coordination with the U.S. Geological Survey in such warnings.

• Forest and Rangeland Renewable Resources Planning Act of August 17, 1974 (RPA) (88 Stat. 

476; 16 U.S.C. 1600-1614) as Amended by National Forest Management Act of October 22, 

1976 (90 Stat. 2949; 16 U.S.C. 1609). (FSM 1920 and FSM 2550.) This act requires 

consideration of the geologic environment through the identification of hazardous conditions and 

the prevention of irreversible damages. The Secretary of Agriculture is required, in the 

development and maintenance of land management plans, to use a systematic interdisciplinary 

approach to achieve integrated consideration of physical, biological, economic, and other sciences.

• Resource Conservation and Recovery Act of 1976 (RCRA) (90 Stat. 2795; 42 U.S.C. 6901) as 

Amended by 92 Stat. 3081. This act, commonly referred to as the Solid Waste Disposal Act, 
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Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

Tahoe National Forest – 85

requires protection of ground water quality and is integrated with the Safe Drinking Water Act of 

December 16, 1974, and Amendments of 1977 (42 U.S.C. 300(f)). (FSM 7420.1.)

• Surface Mining Control and Reclamation Act of August 3, 1977 (SMCRA) 

(30 U.S.C. 1201, 1202, 1211, 1221-43, 1251-79, 1281, 1291, 1309, 1311-16, 1321-28). This act 

enables agencies to take action to prevent water pollution from current mining activities, and also 

promote reclamation of mined areas left without adequate reclamation prior to this act.

• Archaeological Resource Protection Act (ARPA) October 31, 1979 (93 Stat. 721; 16 U.S.C. 

470 aa). This act protects archeological resources, and prohibits the removal, sale, receipt, and 

interstate transport of archeological resources obtained illegally from public lands. Archeological 

resources include paleontological resources in context with archeological resources. Also, this act 

authorizes the Secretary of Agriculture to issue permits for archeological research, investigations, 

studies, and excavations. 

• Comprehensive Environmental Response, Compensation and Liability Act of 1980, as 

amended (CERCLA) (94 Stat. 2767; 42 U.S.C. 9601, et seq). This act provides authority to the 

Environmental Protection Agency and to other federal agencies, including the United States 

Department of Agriculture, to respond to release of hazardous substances, pollutants, and 

constituents. It also provides for joint and several liability to potentially responsible parties (PRPs) 

for cleanup costs of existing water contamination. See also FSM 2160. 

• Federal Cave Resources Protection Act of 1988 (102 Stat. 4546; 16 U.S.C. 4301 et seq). This 

act provides that Federal lands be managed to protect and maintain, to the extent practical, 

significant caves.

FSM-2880.12 - Executive Orders

The following Executive Orders provide direction for geologic resources and services activities on 

National Forest System lands:

• Executive Order 11593, Protection and Enhancement of Cultural Environment, May 13, 

1971 (3 CFR 559, 1971-75 Compilation). This Executive Order directs agencies to preserve, 

restore, and maintain the historic and cultural environment of the Nation.

• Executive Order 12113, Independent Water Project Review, January 5, 1979. This Executive 

Order requires an independent water project review by the Water Resources Council on 

preauthorization reports and preconstruction plans for Federal and federally assisted water and 

related land resource plans. The technical review will evaluate each plan for compliance with the 

Council’s principles and standards, agency procedures, other Federal laws, and goals for public 

involvement.

Affected Environment: Geology

Physiography, Relief and Drainage

The Tahoe National Forest (TNF) is located in the central Sierra Nevada. It is roughly divided into three 

physiographic areas by a glacially sculpted crest zone that trends north-south. The western third of the 
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Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

86 – Tahoe National Forest

survey area is dominated by deeply incised canyons separated by long, narrow, gently sloping ridges. The 

eastern third is characterized by low foothills and broad valleys.

The ascent from the Central Valley through the western third of the Forest toward the crest is gentle; 

with the average slope through a west-to-east transect about 3 to 5 percent. The underlying rock 

formations generally trend northwest by southeast. Drainages are generally toward the southwest, with 

main stream channels cut through and across geologic formations. The headwaters of major drainages 

start in the glaciated crest zone, and descend through gently sloping volcanic and granitic bedrock to 

deeply entrenched V-shaped canyons along the western edge of the area, where metamorphic rocks are 

exposed. Typically, the land surfaces of the folded and faulted metamorphic rocks are steep and angular, 

the land surfaces of granitic rocks rounded, smooth, and often have a basin-like appearance, and the land 

surfaces of volcanic rocks are flat and relatively smooth, reflecting their origin. 

The primary potential impacts to geologic resources resulting from the Travel Management Project 

are associated with cave management, geological special interest areas, paleontological resources, ground 

water management, and areas with a risk of mass movement (primarily debris slides).

Cave Resources, Geologic Special Interest Areas, and Paleontological Resources

The term “cave” means any naturally occurring void, cavity, recess, or system of interconnected passages 

which occurs beneath the surface of the earth or within a cliff or ledge (including any cave resource 

therein, but not including any vug, mine, tunnel, aqueduct, or other manmade excavation) and which is 

large enough to permit an individual to enter, whether or not the entrance is naturally formed or 

manmade. Such term shall include any natural pit, sinkhole, or other feature which is an extension of the 

entrance. There are two known caves on the TNF.

There are two Geologic Special Interest Areas on the TNF: Devil’s Postpile Geologic Area (69 acres, 

postpile geologic feature) and Glacier Meadow Geologic Area (84 acres, glacial geologic features).

There are six known Paleontological sites currently identified on the TNF. These sites are listed below 

in Table 3.02-1.

Table 3.02-1. Paleontological sites currently identified on the Tahoe National Forest

Site Description Potential Impacts

1 Fossilized mastodon remains One unauthorized route

2 Petrified Wood One existing NFTS road

3 Petrified Wood One existing NFTS Motorized Trail

4 Petrified Wood One unauthorized route

5 Paleo Botanical Fossils One unauthorized route and one existing NFTS road

6 Paleo Botanical Fossils One unauthorized route

Groundwater Resources

Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of rock 

formations. Groundwater is recharged from, and eventually flows to, the surface naturally. Discharge of 

groundwater often occurs at springs and seeps and can form wetlands. Roads and motorized trails near 
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Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

Tahoe National Forest – 87

springs and seeps can intercept flow and channel water movement and/or can pollute groundwater 

resources. There are three unauthorized routes and three closed NFTS routes that have the potential to 

impact groundwater resources. These are shown below in Table 3.02-2.

Table 3.02-2. Ground Water Resources Potentially Impacted By Unauthorized or Closed NFTS Routes

Route ID Ground Water Resource

ARM-13 Spring

H45-2 Spring

SV-005 Seep

TKN-J5 Seep/Spring

YRS-066 Spring

YRS-SF4 Seep/Spring

Debris Slides

Road and motorized trail networks in mountainous forest landscapes have the potential to increase the 

susceptibility to shallow landsliding by altering subsurface flow paths. The most common type of 

landslide feature found on the TNF is debris slides. Debris slides are a type of soil movement that usually 

occurs on steep slopes with shallow soils over bedrock. Roads and motorized trails that cross debris slides 

can increase debris slide activity, increasing sediment delivery to channels. The risk of debris slides is 

covered in the erosion model presented in the Soils Section.

Abandoned Mine Lands

Some abandoned mine land (AML) sites can be a concern for public safety (e.g., mine shafts, hazardous 

substances, etc). There are 74 AML sites currently identified on the TNF that are within 100 feet of roads 

or motorized trails. Thirty-eight sites are along existing National Forest Transportation System (NFTS) 

roads or NFTS motorized trails. The other 36 of these AML sites are along unauthorized or closed NFTS

routes.

Environmental Consequences: Geology

Cave Resources, Geologic Special Interest Areas, and Paleontological Resources

Neither of the two known caves on the TNF is within 1⁄4 mile of a road or motorized trail and therefore 

would not be affected by any of the alternatives.

No changes in management of the Geologic Special Interest Areas (GSIA) would occur under 

implementation of any of the alternatives. Motorized vehicle use within these GSIAs is either excluded or 

discouraged. Therefore, native geologic features within these GSIAs would not be impacted by motorized 

vehicle activity. There are no environmental consequences associated with GSIAs in any of the 

alternatives.

Paleontological resources on the TNF include plant and animal fossils and petrified wood. There are 

six known Paleontological sites currently identified on the TNF. All six of the sites could be impacted by 

motorized use in Alternative 1 (no action). All of the action alternatives reduce the number of sites 
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88 – Tahoe National Forest

potentially impacted by motorized use. The number of sites potentially impacted by motorized use in each 

alternative is shown in Table 3.02-3.

Table 3.02-3. Paleontological resources on the TNF potentially impacted by motorized vehicles by alternative

Site Description Potential Impacts Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

1 Fossilized 

mastodon remains

Motorized trail added to NFTS X X

2 Petrified Wood One existing NFTS road X X X X X X X

3 Petrified Wood One existing NFTS Motorized 

Trail

X X X X X X X

4 Petrified Wood Motorized trail added to NFTS X X X X X

5 Paleo Botanical 

Fossils

Motorized trail added to NFTS

One existing NFTS road

X X X X X X X

6 Paleo Botanical 

Fossils

One motorized trail unauthorized for motorized useX

Total Number 6 4 3 3 5 4 4

Groundwater Resources

The potential effects of routes on aquatic species are covered in Section 3.03 (Terrestrial and Aquatic 

Species). The potential effects of groundwater on erosion rates are covered in the Soil Resource section 

and in the Appendix A (Site Specific Road, Trail and Open Area Information). Given the scale of this 

project, there would be little measurable effect of this project to water quality of groundwater resources.

All additions to the NFTS which could impact groundwater resources have mitigation measures specified 

in Appendix A to reduce or eliminate any potential adverse effects. These mitigation measures for ground 

water resources are summarized by alternative in Table 3.02-4.

Table 3.02-4. Mitigation measures to protect groundwater resources by alternative

Route ID Ground Water 

Resource

Mitigation Measure 

Required

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

ARM-13 Spring None, no impact to spring

H45-2 Spring Place barriers X

SV-005 Seep None, no impact to seep

TKN-J5 Seep/Spring Redirect water flow X X X X

YRS-066 Spring Install drainage structures X X X

YRS-SF4 Seep/Spring Install waterbars to control 

road drainage

X X

Total Number of Mitigations 0 2 0 0 4 3 1

Abandoned Mine Lands (AML)

To assess the potential health and safety risks from abandoned mine lands effects, the alternatives are 

compared by the number of known, mapped AML sites within 100 feet of roads and motorized trails.

There are currently 74 AML sites within 100 feet of existing NFTS and unauthorized motorized routes.
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Tahoe National Forest – 89

Those alternatives with the greatest number of AML sites within 100 feet of roads and motorized trails are 

expected to have the highest risk to public safety. There is no way of knowing how many people using the 

roads and motorized trails may be accessing the mine sites. Table 3.02-5 shows the number of AML sites 

which could have potential public safety concerns related to motorized public access. The No Action 

Alternative (Alternative 1) would have the highest risk to public safety. Alternative 3 would have the 

lowest risk to public safety because it does not add any unauthorized routes to the NFTS and it therefore 

has the lowest number of AML sites. All other action alternatives would add between two and four

unauthorized routes to the NFTS near AML sites. Mitigation measures to assure public safety is included 

in Appendix A (Site Specific Road, Trail and Open Area Information) for these sites. Mitigation measures 

typically are to seal off any hazardous openings such as mine adits.

Table 3.02-5. Number of Abandoned Mine Land (AML) Sites within 100 Feet of NFTS Roads and Motorized 

Trails by Alternative

Alternative Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Number of AML Sites within 100 feet 74 42 38 40 42 41 41

Prohibition of Cross Country Travel: All of the action alternatives prohibit cross country travel.

This prohibition would reduce the public risk caused by the presence of AML features across the forest. It 

would also prevent the proliferation of any new motorized trails unauthorized for motorized use which 

could increase the public safety risk. Prohibition of cross country travel would decrease the number AML 

sites within 100 feet of roads and motorized trails by 38 sites. The changes in the number of AML sites 

within 100 feet of roads and motorized trails resulting from the prohibition of cross country travel are 

displayed in Table 3.02-6.

Table 3.02-6. Changes in the number AML sites within 100 feet of motorized vehicle access due to the 

prohibition of cross country travel 

Alternative Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Changes in number of AML Sites within 100 ft. 0 -36 -36 -36 -36 -36 -36

Additions to the National Forest Transportation System (NFTS): There are no additions to the 

NFTS under Alternative 1. Adding motorized trails to the NFTS within 100 feet of abandoned mine land 

(AML) sites would have minimal new effects to public safety. Appendix A (Site Specific Road, Trail and 

Open Area Information), has mitigations needed to add the routes to the NFTS with minimal impacts to

user safety. The changes in AML sites within 100 feet resulting from the additions to the NFTS are 

displayed in Table 3.02-7.

Table 3.02-7. Changes in AML sites within 100 feet of roads and motorized trails due to additions to the NFTS

Alternative Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Number of AML Sites within 100’ 0 +4 0 +2 +4 +3 +3
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90 – Tahoe National Forest

Establishing motorized “Open Areas”: There are no “Open Areas” being established within 100 

feet of AML sites in any of the action alternatives.

Changes to NFTS: Changing the class of vehicle allowed to use a particular NFTS road or motorized 

trail or the season of use does not change the impacts to and from AML sites. There are no Maintenance 

Level 1 roads being reopened within 100 feet of AML sites in any of the action alternatives.

Cumulative Effects: All action alternatives would result in a decrease in public health and safety 

risks associated with motorized access to abandoned mine land sites. Alternative 3 would decrease the 

number of AML sites within 100 feet of roads and motorized trails by 36 sites. The rest of the action 

alternatives would decrease the number of AML sites adjacent to roads and motorized trails by 32 to 34 

sites. The cumulative effects to public health and safety from AMLs are the same as displayed in Table 

3.02-5.

Soil Resources _________________________________________

Introduction

The soil resource provides many essential functions for National Forest System (NFS) lands. It sustains 

plant growth that provides forages, fiber, wildlife habitat, and watershed protection. It absorbs 

precipitation, stores water for plant growth, and gradually releases surplus water which attenuates runoff 

rates. It sustains microorganisms which recycle nutrients for continued plant growth. The National Forest 

Management Act of 1976 and other acts recognized the fundamental need to protect, and where 

appropriate improve, the quality of soil. The proposed action could potentially impact soil productivity 

and its other ecosystem functions and is therefore addressed.

The primary concern or effect of this project on the soil resource is the potential for soil erosion and 

subsequent effects on soil productivity or the ability of the soil to produce vegetation. Secondary effects 

from erosion are a reduction in the soil hydrologic function (e.g., the loss of soil depth, infiltration 

capacity and permeability).

The erosion that may occur from the trail or road surface is a concern regarding loss or degradation of 

the facility, but not a particular concern for the soil resource, because the travel-way surface is a dedicated 

use and no longer dedicated to growing vegetation. The effects analysis for the soil resource will focus on 

the risk of soil erosion from trail/road runoff water to the soil adjacent to or down slope from the route. 

Erosion and sediment generated by the trail or road surface may be a concern to water quality if there is 

the potential for its delivery to a drainage feature. (Refer to the Hydrology section).

Analysis Framework: Statute, Regulation, Forest Plan, and Other Direction

Direction specifically relevant to the proposed action as it affects soil resource includes:

• National Forest Management Act of 1976. Renewable Resource Program. “(C) recognize the 

fundamental need to protect and where appropriate, improve the quality of soil, water, and air 

resources.”

• National Soil Management Handbook. The Soil Management Handbook (USDA 1991) is a 

national soils handbook that defines soil productivity and components of soil productivity, 
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Tahoe National Forest – 91

establishes guidance for measuring soil productivity, and establishes thresholds to assist in forest 

planning.

Management activities cause varying degrees of soil disturbances, which may or may not cause a 

significant change in productivity. Soil quality standards (threshold values where soil disturbances 

become detrimental, that is, result in significant change) are intended for areas where management 

prescriptions are being applied, such as timber harvest areas and range allotments. They are not 

intended to apply to administrative sites or other areas with dedicated uses.

• Region 5 Soil Management Handbook Supplement. The Forest Service Region 5 Soil 

Management Handbook Supplement establishes regional soil quality analysis standards (SQS, 

USDA 1995). The Region 5 soil quality analysis standards address three basic elements for the 

Soil Resource: 1) soil productivity (including soil loss, porosity; and organic matter), 2) soil 

hydrologic function, and 3) soil buffering capacity. The analysis standards apply only to those 

areas dedicated to growing vegetation. They are not applied to lands with other dedicated uses, 

such as developed campgrounds, administrative facilities or in this case, the actual land surface 

authorized for travel by the public using various kinds of vehicles, both licensed or non-licensed.

• Regional Forester’s Letter (dated Feb 5, 2007). This letter provided clarification to Forest 

Supervisors on the appropriate use of the R5 Soil Management Handbook Supplement (R5 FSH 

Supplement 2509.18-95-1). It states in part:

 Analysis or evaluation of soil condition is the intended use of the thresholds and indicators in 

R5 FSH 2509.18-95-1. They are not a set of mandatory standards or requirements. They should 

not be referred to as binding or mandatory requirements in NEPA documents. Standards and 

guidelines in Forest Land and Resource Management Plans provide the relevant substantive 

standard to comply with NFMA.

 The thresholds and indicators represent desired conditions for the soil resource. Utilization of 

the thresholds and indicators provides a consistent method to analyze, describe, and report on 

soil condition throughout the Region.

• Tahoe National Forest Land and Resources Management Plan (LRMP) direction for soil and 

water resources includes the following:

 Standards and Guidelines for Riparian Conservation Areas and Critical Aquatic Refuges (TNF 

LRMP as amended by the SNFPA ROD (2004), pp. 62 - 65). Evaluate new proposed 

management activities within CARs and RCAs during environmental analysis to determine 

consistency with the riparian conservation objectives at the project level and the AMS goals for 

the landscape. Ensure that appropriate mitigation measures are enacted to (1) minimize the 

risk of activity-related sediment entering aquatic systems and (2) minimize impacts to habitat 

for aquatic- or riparian-dependent plant and animal species.

 Consistent with the first standard and guideline above, a Riparian Conservation Objective 

(RCO) analysis has been completed for this project. (Refer to Appendix I “Riparian 
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Conservation Objectives.”) Appendix I describes how the project is consistent with the RCOs 

and the applicable standards and guidelines (listed above).

 Water Quality Protection (TNF LRMP, pg. V-35). Use Best Management Practices (BMPs) to 

meet water quality objectives and maintain and improve the quality of surface water on the 

Forest.

 Best Management Practices (BMPs) are implemented as mitigation measures specified in 

Appendix A (Site Specific Road, Trail and Open Area Information) for any motorized trail to 

be added to the National Forest Transportation System or any lands to be established as “Open 

Areas.” These mitigation measures would meet water quality objectives and maintain and 

improve the quality of surface water on the Forest.

 Soil Restoration (TNF LRMP, pg. V-35). During project planning, identify areas of soil 

damage and abandoned roads in need of rehabilitation. Include these areas in project plans for 

restoration and improvement.

 Areas of soil damage and abandoned roads in need of rehabilitation were identified in 

association with this project and documented in the project record. Project plans for restoration 

and improvement would be implemented through separate NEPA decisions as funding permits.

 Unstable Areas (TNF LRMP, pg. V-38). Allow no land-disturbing activities on land classed as 

extremely unstable, unless a geotechnical investigation determines certain activities are 

appropriate.

 Any motorized trail additions to the NFTS on extremely unstable lands requiring geotechnical 

investigation were excluded from consideration in all alternatives.

Effects Analysis Methodology

This is a site specific project, for which there is two levels of analysis. First, there is site-specific analysis 

of the individual routes proposed for addition to the NFTS. This detailed analysis is by route and is 

included in Appendix A (and the project record).

Second, there is the analysis of each alternative as a whole, which is informed by the site-specific 

route analysis noted above and other information. The discussion of the direct, indirect, and cumulative 

effects of each alternative is in a summary form. For ease of documentation and understanding, the effects 

of the alternatives are described separately for five discreet actions and then combined to provide the total 

direct and indirect effects of each alternative (see below). The combination of these discreet actions is 

then added to the past, present, and reasonably foreseeable actions in the cumulative effects analysis. The 

five discreet actions common to all action alternatives are: (1) Prohibition of cross country motor vehicle 

travel; (2) Additions to the NFTS; (3) Establishment of motorized “Open Areas”; (4) Changes to the 

existing NFTS (which includes: change in class of vehicles resulting from approval of mixed use, change 

in class of vehicle resulting from changes in maintenance levels, change in season of use, and reopening 

Maintenance Level 1 roads to motorized use); and (5) Amendments to the Forest Plan. This discussion is 

the focus of this Effects Analysis Methodology section.
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The Effects Analysis Methodology section describes the methodology used for the effects analysis in 

Chapter 3, not the site-specific analysis of each route. It addresses impacts relevant to the soil resource, 

soil resource-specific assumptions, soil resource indicators to be measured, including justification as to 

why they were chosen, sources of information used to support the analysis, timeframes (short term and 

long term), and spatial boundary of the effects analysis. 

The Effects Analysis Methodology focuses on the assumptions, methodology, and indicators for 

addressing the direct and indirect effects of each of the five actions and the cumulative effects of 

implementing the alternative as a whole. The conclusions of the analysis in the Environmental 

Consequences section present the direct and indirect effects of implementing the alternative as a whole 

addressing the effects of each of the five proposed actions. Then, the cumulative effects of implementing 

each alternative (the direct and indirect effects of this action in combination with the effects of past, 

present, and reasonably foreseeable future actions) are displayed.

Assumptions specific to the soil resources analysis

• Authorized travel routes are a dedicated use of the soil resource and are not a concern for 

productivity because the soil is no longer dedicated to growing vegetation. The soil dedicated to 

growing vegetation, which may be affected by runoff water drainage from authorized routes is the 

principle concern addressed here. 

• Continued unauthorized cross country travel by motor vehicles will cause adverse effects to soil 

productivity from destruction of vegetative cover, soil compaction due to motorized use, alteration 

of drainage patterns, and increases in erosion risk to soil productivity. 

• Erosion risk is influenced by soil type (inherent soil erosivity), topography, precipitation (amount 

and type), presence of geo-debris slide features, and the type, amount, and season of use which can 

cause rutting and a subsequent loss of water control.

• Erosion from motor vehicle use of native-surface routes is increased or often caused by wet season 

use and/or higher levels of traffic and is reduced by maintenance of road drainage features 

(waterbars, ditches). The erosion is caused by concentrated road water runoff.

• The unauthorized routes receive no maintenance and the lack of erosion and water control poses a 

high risk of impact to soil resources.

• User-created motorized trails were not constructed to NFTS standards. These trails are not 

maintained and are assumed to be higher risk routes in terms of erosion and water quality risks.

• This analysis assumes that around 75 percent of the hydrologic footprint of the unauthorized or 

closed NFTS routes closed to cross country travel would recover vegetative soil cover and have a 

reduced risk of erosion within 20 to 30 years. These assumptions are based on the personal 

observations and experiences of the watershed and vegetation management staff on the TNF. 

• The spatial boundary for the effects analysis is the forest boundary. Within the forest boundary, 

erosion potential has been analyzed at multiple scales. 
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Data Sources

• Route-specific data collected in the field using the established protocol: OHV green-yellow-red 

inventories which are documented in Appendix A (Site Specific Road, Trail and Open Area 

Information).

• GIS analyses of erosion risk, route miles, etc.

• Recent Tahoe National Forest project NEPA documents.

• Air and ground photos, personal knowledge, and anecdotal information documenting the time 

required for passive restoration of routes closed to motor vehicle traffic (recovery time may vary

based on precipitation, elevation, aspect, and other factors).

Soil Resources Indicators 

• Acres open to cross country motor vehicle travel by soil erosion hazard rating.

• Miles of unauthorized routes open for motor vehicle travel by R-5 soil erosion hazard (R-5 EHR) 

rating.

• Miles of closed ML 1 roads receiving motorized use by R-5 EHR rating.

• Miles passively recovered due to vegetative recovery over long-term by soil erosion hazard rating

• Cumulative effects – loss of long-term soil productivity – Equivalent Roaded Areas from 

cumulative watershed effects analysis are used to track the transportation footprint and to assess 

the cumulative effects to long-term soil productivity. Cumulative effects on soil productivity 

include:

 Cumulative effects from unauthorized use (No Action).

 Cumulative effects in unauthorized areas that are expected to recover after a cross-country 

closure is implemented.

 Cumulative effects in areas that are not expected to recover passively after a cross-country 

closure is implemented.

 Cumulative effects from implementation of the particular travel system for each alternative.

Soil Resource Methodology by Action

1) Direct/indirect effects of the prohibition of cross country motor vehicle travel

Considerations: Cross country motor vehicle travel has led to the proliferation of compacted soils 

outside of the designated Tahoe NFTS. The major effects of cross country motor vehicle travel on soil 

resources include the loss of vegetative cover, increasing levels of soil compaction, soil displacement, 

surface soil loss, and loss of soil productivity. Prohibiting cross country motor vehicle travel would end 

motorized use on routes and areas beyond the authorized NFTS. In the short term, the unauthorized and 

closed NFTS routes and areas disturbed by motor-vehicle use would not change much because removal of 

vegetation, compaction of soils, and alteration of drainage patterns require time to heal without active 

restoration. Passive vegetative recovery of most previously disturbed areas is estimated to take place over 

a 20 to 30 year period. It is also assumed that around 75 percent of the routes would recover and have a 
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reduced risk of erosion within that 20 to 30 year period. These assumptions are based on the personal 

observations and experiences of the watershed staff of the TNF.

Cross country travel has resulted in approximately 869 miles of unauthorized routes and another 830 

miles of closed NFTS routes that are still receiving some use on the TNF. As discussed below in the 

inventory results section, some routes are stable and others need maintenance/mitigation. Site specific 

erosion risks for these routes are displayed in Appendix A and Appendix L.

Short-term timeframe: 1 year.

Long-term timeframe: The period used for long-term effects analysis is 20 to 30 years. This is a 

reasonable timeframe to think about and predict the expected vegetative recovery (and reduction in 

erosion) for areas disturbed by unauthorized use. 

Spatial boundary: Tahoe National Forest boundary.

Indicator(s): (1) Acres of prohibition of cross country travel by alternative; (2) Miles of unauthorized 

routes and R-5 EHR ratings on the TNF; (3) Miles of native surface roads and motorized trails open for 

motorized use in each of R-5 EHR ratings.

Methodology: GIS analyses of acres of FS lands open for cross country travel by alternative, miles of 

unauthorized routes, and R-5 EHR ratings. 

Rationale: General guidelines in the National Soil Management Handbook and Region 5 Soil 

Management Handbook Supplement.

Direct Effects: Prohibiting cross country motor vehicle travel would end motorized traffic in areas 

beyond the NFTS. Generally for the existing unauthorized and closed NFTS routes and use areas, the 

direct effects to soil productivity have already occurred. The direct effects during construction of a NFTS 

facility or by unauthorized motor vehicle traffic were: loss of soil cover, physical displacement of soil; 

loss of soil depth; and loss in soil hydrologic function due to compaction.

Indirect Effects from unauthorized use: The indirect effects of the prohibition of cross county 

motorized vehicle travel would be gradual reductions in soil erosion and increases in soil productivity as 

recovery occurs and further disturbances decrease in the long-term. The net effect in the long-term would 

be vegetative recovery, a decrease in compaction and erosion, and a restoration of soil hydrologic 

function within unauthorized route treads. Recovery rates would be variable. Once closed to public use, 

the degree to which site productivity on unauthorized routes recover depends on current condition of the 

route, location on the landscape, location on the Forest and the effectiveness of enforcing the closure. 

Seldom used routes and some user created routes would likely recover within the cumulative effects 

analysis timeframe of 20 to 30 years. More long-standing routes or routes that experience moderate to 

high use would take longer to recover, with site productivity approaching natural range at the end of the 

cumulative effects analysis timeframe. Actively eroding routes would experience limited recovery (less 

erosion, higher productivity) in 20 to 30 years without active restoration.

2) Direct/indirect effects of additions to the NFTS

Considerations: The characteristics of roads and motorized trails are important in defining the affected 

environment for soil and for analyzing the effects of the proposed actions. Some roads and motorized 
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96 – Tahoe National Forest

trails are a lower risk to soil resources than others. Lower-risk roads and motorized trails tend to be more 

stable and generally have less concentration of water runoff and surface soil loss and a lower potential for 

soil erosion adjacent to the route and sediment production and transport. Native surface motorized roads 

and trails generally have a higher risk of concentrating road runoff and surface erosion and increased 

erosion adjacent to the route than surfaced routes and are considered higher risk routes.

The effects of adding routes to the NFTS are focuses on presently unauthorized routes that would be 

added to the system routes. This is a change from unauthorized and unmaintained to NFTS status which 

included maintaining routes for resource protection.

Short-term timeframe: 1 year.

Long-term timeframe: The period used for long-term effects analysis is 20 to 30 years. This is a 

reasonable timeframe to think about and predict the expected vegetative recovery (and reduction in 

erosion) for areas disturbed by unauthorized use. This is also the same recovery period used for the 

Cumulative Watershed Effects analysis in this document.

Spatial boundary: Forest boundary.

Indicator(s): (1) Miles of unauthorized routes added to the NFTS by R-5 EHR rating; (2) Miles of 

native surface, roads and motorized trails by R-5 EHR rating.

Methodology: (1) erosion potential for the soils on the TNF was modeled using GIS, R-5 EHR 

rating, and the Ecosystem Management Decision Support model and analyzed at a range of watershed 

scales; (2) GIS analysis of existing unauthorized routes and the R-5 EHR rating.

Rationale: Analysis guidelines in the National Soil Management Handbook and Region 5 Soil 

Management Handbook Supplement.

Direct Effects: Additions to the system would have minimal effects to soil resources, because these 

motorized trails are already part of the existing disturbance footprint and would be managed according to 

TNF trail and resource standards. Generally for the existing unauthorized and closed NFTS routes, the 

direct effects to soil productivity have already occurred. The direct effects were: loss of soil cover,

physical displacement of soil during construction of a NFTS facility or caused by unauthorized motor

vehicle traffic; loss of soil productivity from the displacement and loss of soil depth; and loss in soil 

hydrologic function due to increased compaction and loss of soil.

Indirect Effects: The indirect effects of adding the proposed routes to the NFTS would be similar to 

current effects. The primary difference would be that as designated trails these routes would be managed 

according to TNF trail and resource standards which would decrease any current negative effects caused 

by those routes.

3) Direct/Indirect effects of establishing motorized “Open Areas”

Considerations: The proposed establishment of “Open Areas” are in areas not dedicated to growing 

vegetation and have been used by motor vehicles for years. The soil quality standards of long-term soil 

productivity do not apply to areas not dedicated to growing vegetation. The potential erosion effects of 

establishing “Open Areas” are covered in the Hydrology Section of this chapter. Proposed “Open Areas” 

will not be covered in the effects analysis for soils.
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Rationale: Analysis guidelines in the National Soil Management Handbook and Region 5 Soil 

Management Handbook Supplement.

4) Direct/indirect effects of changes to the existing NFTS - this includes changing 

the vehicle class and/or season of use and reopening Maintenance Level 1 Roads

Considerations: Changing the class of vehicle allowed to use a particular NFTS road could change the 

impacts to soil and watershed resources due to the change in road surface. Therefore, these roads are 

considered to have an increased risk of erosion even though they already have “hardened” surfaces that 

lack vegetation. It is likely that direct impacts to soil and watershed resources occurred when the road was 

constructed and many of these routes are stable. Impacts may still be occurring if the road is collecting 

and concentrating overland flow of water and increasing erosion rates. These indirect and cumulative 

impacts would continue regardless of the type of vehicle using the route. When the maintenance level of a 

particular route changes (the maintenance level does not always change when class of vehicle changes), 

the risk of erosion can increase. However, all roads would be maintained to TNF standards for resource 

protection no matter what maintenance level.

Native surface roads and motorized trails are most susceptible to damage by motor vehicles when 

wet. The condition of native surface roads and motorized trailscan quickly decline during winter or wet 

weather use due to rutting. Wet season use of native surface roads and motorized trails often leaves ruts 

which channel water and increase the erosive power of that water, this can lead to increased erosion both 

on the trail and adjacent to the trail. Many of the impacts found during field surveys were caused by wet 

season use of routes. 

Implementing seasonal closures in Alternatives 4, 5, and 6 would reduce rutting and subsequent 

channeling of surface water runoff. Seasonal closures would decrease the potential effects of motorized 

vehicle use on native surface roads and motorized trails by decreasing erosion and sedimentation.

Short-term timeframe: 1 year.

Long-term timeframe: The period used for long-term effects analysis is 20 to 30 years. This is a 

reasonable timeframe to think about and predict the expected vegetative recovery (and reduction in 

erosion) for areas disturbed by unauthorized use. This is also the same recovery period used for the 

Cumulative Watershed Effects analysis in this document.

Spatial boundary: Forest boundary.

Indicator(s): (1) Miles of unauthorized routes displayed by miles by R-5 EHR rating; (2) Miles of 

native surface roads and motorized trails open for motor vehicle use displayed by R-5 EHR rating; (3) 

miles of native surface roads and motorized trails subject to seasonal use restrictions.

Methodology: (1) erosion potential for the soils on the TNF was modeled using GIS, R-5 EHR 

rating, and the Ecosystem Management Decision Support model; (2) GIS analysis of existing 

unauthorized routes. 

Rationale: Analysis guidelines in the National Soil Management Handbook and Region 5 Soil 

Management Handbook Supplement.

Direct Effects: The direct effects of changing class of vehicle would be small, because these are 

existing routes. The direct effects of changing the season of use in Alternatives 4, 5, and 6 would be to 
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98 – Tahoe National Forest

decrease the mechanical erosion caused by motor vehicles during the part of the wet season when soils 

are most susceptible to damage. Reopening Maintenance Level 1 roads would increase compaction on the 

tread of the road.

Indirect Effects: The indirect effects of changing class of vehicle would include a rougher road 

surface which could increase the potential for channelized water movement along the route. The main 

indirect effects of changing the season of use would be a decrease in rutting, channelized water movement 

along the route, and decreased erosion potential during the seasonal closure. Maintenance Level 1 roads 

were previously engineered NFTS routes that were put into “storage” until needed for Forest 

management. Closed NFTS routes that are proposed to be opened are roads that were engineered to 

control drainage and erosion and are thus designed to minimize impacts to soil resources.

5) Forest Plan Amendment

Considerations: The Tahoe National Forest Land and Resource Management Plan (LRMP) would be 

amended to remove the November 1 to May 1 seasonal closure from the Sugar Pine area (Management 

Area 84 Humbug Sailor) on key winter deer range to improve motorized recreation opportunities. This 

would result in 10.5 miles of routes that is currently closed to motorized use during the wet season. This 

action would result in motorized vehicle use during the winter months when roads and trails are subject to 

damage due to wet season use. In some alternatives the deer winter range seasonal restrictions are 

replaced by wet weather seasonal restrictions. Alternatives 2, 5, and 6 would remove that closure and 

make the routes in the management area subject to wet season use; however, the wet weather seasonal 

closure proposed in Alternatives 5 and 6 would replace the current closure with one that is 2 months

shorter.

Short-term timeframe: 1 year.

Long-term timeframe: The period used for long-term effects analysis is 20-30 years. This is a 

reasonable timeframe to think about and predict the expected vegetative recovery (and reduction in 

erosion) for areas disturbed by unauthorized use.

Spatial boundary: Management Area 84 Humbug Sailor – 20,238 acres gross (17,554 acres Forest 

Service lands).

Indicator(s): Number of Amendments

Methodology: GIS analysis

Rationale: Analysis guidelines in the National Soil Management Handbook and Region 5 Soil 

Management Handbook Supplement.

Direct and Indirect Effects: Native surface roads and motorized trails are most susceptible to 

damage by motor vehicles when wet. The condition of native surface roads and motorized trails can 

quickly decline during winter or wet weather use due to rutting. Wet season use of native surface roads 

and motorized trails often leaves ruts which channel water and increase the erosive power of that water, 

this can lead to increased erosion both on the trail and adjacent to the trail. Many of the impacts found 

during field surveys were caused by wet season use of routes.
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6) Cumulative Effects

Considerations: The cumulative effects analysis presented here is for the whole geographic area of the 

Tahoe National Forest. Short-term effects take place within 1-5 years. Long-term effects take 20-30 years.

They represent the additive, incremental effects of past, present, and reasonably foreseeable future 

activities, actions, and decisions on the soil resource. The current condition of the roads and trails, the 

number of private roads, and the soil damage at primitive campsites are all a reflection of past and current 

management activities. Management actions affect traffic, user-created motorized routes, maintenance, 

the effectiveness of closures, and recovery of closed routes. Cumulatively, these actions influence tread 

wear and soil erosion.

Soil cumulative effects parallel the hydrology cumulative effects. The common ground is the 

Equivalent Roaded Acre (ERA) concept. All ground disturbances in the watershed are given a coefficient 

value. Roads, mechanical thinning operations, prescribed fire, wildfire, etc. are accounted for relative to 

past, present, and expected future management activity levels. The USDA Forest Service Region 5 

methodology is used to determine the overall disturbed footprint. The disturbed footprint is a semiquantitative measure of acres of detrimental soil disturbance and hence an approximation of change in 

Soil Quality as defined by the R5 Soil Quality Standards (USDA 1995c).

Short-term timeframe: not applicable; cumulative effects analysis will be done only for the longterm time frame.

Long-term timeframe: The period used for long-term effects analysis is 20 to 30 years. This is a 

reasonable timeframe to think about and predict the expected vegetative recovery (and reduction in 

erosion) for areas disturbed by unauthorized use. 

Spatial boundary: Forest boundary. In the DEIS, the cumulative effects analysis was compiled at the 

HUC7 scale. Comments received on the DEIS said that this analysis was too complex and confusing. 

Upon further review of the DEIS data, the decision was made to use HUC6 watersheds for the SDEIS

analysis. This decreases the number of watersheds by around 80 percent, does not change the results of 

the analysis, and makes the analysis more understandable. This scale is large enough to encompass the 

effects of management activities, but not so large as to mask the effects of the proposed actions.

Indicator(s): Equivalent Roaded Acres from Hydrology analysis.

Methodology: Utilize observations and understanding of short-term effects to soil productivity to 

estimate long-term expected cumulative effects on soil productivity. 

Rationale: Analysis guidelines in the National Soil Management Handbook and Region 5 Soil 

Management Handbook Supplement.

Affected Environment: Soil Resources

Soils on the Tahoe National Forest

Soils on the Tahoe National Forest can be separated into 3 physiographic groups, oriented from west to 

east:
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Dominantly Nearly Level to Very Steep Soils of the Westside

Soils in this group are well drained and somewhat excessively drained. They formed in material 

weathered from volcanic, metasedimentary, granitic, or ultra basic rock, as well as in glacial or alluvial 

deposits. Rock outcrops are numerous in many areas. Slopes are 2 to 75 percent.

These soils are on the lower slopes of the western Sierra Nevada, at elevations of 1,800 to 6,000 feet. 

The annual precipitation is 40 to 80 inches, and the frost-free growing season is 130 to 200 days.

Some of the major soil series in this zone are Hurlbut, Deadwood, Putt, Cohasset, Jocal, Holland, 

McCarthy, Crozier, and Ledmount. The soils in this zone make up about 33 percent of the survey area.

Soils in this zone usually have more clay and are more susceptible to rutting and erosion, than those at 

higher elevations. Likewise, these soils are accessible to OHV use throughout the year because 

precipitation in this zone is mostly rain.

Dominantly Nearly Level to Very Steep Soils of High Elevation Mountainsides

The soils in this group are excessively drained to moderately well drained. They formed in material 

weathered from volcanic, metasedimentary, and granitic rock, as well as glacial or alluvial deposits. Rock 

outcrops are numerous in many areas. Glacial rock land also occurs throughout the area. Slopes range 

from 2 to 75 percent. These soils are along the crest of the Sierra Nevada, at elevations of 5,400 to 10,000 

feet. The annual precipitation is 35 to 80 inches, and the frost-free season is 25 to 125 days. Some of the 

major soil series in this zone are Tallac, Smokey, Meiss, Bucking, Ledford, Fugawee, Waca, and Ahart.

Areas of nearly level to very steep terrain are found in this zone. Rock outcrops are also mapped in this 

zone. The soils in this zone make up about 48 percent of the survey area. Soils are generally loamy to 

sandy, and have more rock fragments. Gully erosion is a hazard in this zone. Snow cover makes the 

season of use shorter, and wet season closures are less of an issue than in the soils of the lower Westside.

Dominantly Nearly Level to Very Steep Soils of the Eastside

The soils in this group are somewhat excessively drained to well drained. They form in material 

weathered from volcanic, rhyolitic, and granitic rock, and alluvial deposits. Rock outcrops are numerous 

in many areas. Slopes range from 2 to 75 percent. These soils are on the lower slopes of the eastern Sierra 

Nevada, and the Verdi ranges, at elevations of 4,800 to 6,500 feet. The annual precipitation is 15 to 40 

inches, and the frost-free growing season is 20 to 75 days. Some of the major soil series in this zone are 

Euer, Martis, Aldi, Franktown, Kyburz, Trojan, and Portola. The soils in this zone make up about 19 

percent of the survey area. Soils are generally loamy to sandy, and have more rock. These soils have some 

of the lowest erosion rates on the Tahoe National Forest (TNF).

Soil Erosion Risk Assessment

Many factors can influence the risk of erosion and potential impacts to watershed resources including: 

soil erosivity; stream density; and the type and density of roads on the landscape. The presence of highly 

erosive soils/landscapes or a high density of native-surfaced, motorized routes does not mean that there 

would be negative effects to soil resources. But the presence of both high erosion risks and a high density 
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Tahoe National Forest – 101

of motorized routes indicates that there could be a higher risk of accelerated erosion and sediment 

production due to motorized roads and trails. 

The inherent risk of erosion of the soils within the TNF was assessed using two methods: the soil 

erosion hazard rating found in TNF Soil Resource Inventory and the Ecosystem Management Decision 

Support Model (EMDS).

The soil resource inventory erosion hazard ratings were mapped at a large scale. Table 3.02-8 shows 

the erosion hazard ratings associated with the higher risk routes in the NFTS, the unauthorized routes, and 

higher risk routes on private land. Seventy-five percent of the currently existing routes within the 

boundary of the TNF are on high erosion hazard rated (EHR) soils. Eighteen percent are on moderate 

EHR soils and six percent are on very high EHR soils. Routes with moderate EHR tend to be on ridgetops and valley bottoms where topography is generally flatter. Therefore the risk of erosion is lower than 

on the steeper slopes found on the majority of the TNF.

Table 3.02-8. Native surface road and trails (higher risk routes) by Erosion Hazard Rating1

Erosion Hazard Rating Alt 1

National Forest Transportation System (miles) Very High 96

High 1,331

Moderate 337

N/A 11

Unauthorized Routes and ML 1 Routes receiving 

unauthorized use (miles)

Very High 111

High 1272

Moderate 290

N/A 21

Private Roads (miles) Very High 80

High 1,293

Moderate 415

N/A 27

Total (miles) Very High 287

High 3,896

Moderate 1,042

N/A 59

1 Other system routes are not inculded in this total. N/A includes areas such as rock outcroppings.

Using the soil erosion risk ratings found in the Soil Resource Inventory (See Table 3.02-8), 82 percent

of the Forest has a high to very high erosion hazard. The inherent risk of erosion of the soils within the 

TNF was refined using the Ecosystem Management Decision Support Model (EMDS). The parameters 

used in the EMDS model to assess soil erosion risk were 1) presence of geo-debris slides, 2) soil 

erodibility, 3) slope, and 4) precipitation. The EMDS model compared the K factor, percent slope, 

precipitation, and presence of geodebris slides of each route segment (~300 meters) to all other road and 

motorized trail segments on the TNF. The result is a relative erosion risk value assigned between 0 

(highest risk) and 1 (lowest risk) for each 300 meter segment of every road and motorized trail (See 
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102 – Tahoe National Forest

Appendix L). The EMDS scores for the length of roads and motorized trails in each HUC6 watershed 

were averaged to define the potential erosion risks on the watersheds on the TNF. The modeled erosion is 

generally higher on much of the west slope of the TNF. This is due to the steeply sloping topography of 

many of the watersheds, the potential presence of geo-debris slides, higher precipitation values, and finertextured, more erosive soils. The modeled risk is lower on the east-side of the TNF due to coarser textured 

soils and less steep slopes.

The EMDS risk assessment is internally referenced to the soils on the TNF. This means that the 

lowest EMDS erosion risk score modeled using TNF data was defined as the highest potential erosion risk 

possible on the TNF and the highest EMDS score was defined as the lowest potential erosion risk possible 

on the TNF. This information was used to prioritize field surveys. In general, modeled risk of erosion was

higher than actual amount of resource damage found during field inventories. The GIS analysis predicted 

more water crossings than were found during field inventories. This is partially due to the fact the 

ephemeral stream GIS coverage used in this analysis has not been fully field verified across the entire 

TNF. Geo-debris slides also tend to be over-estimated in the model. Routes were usually higher on the 

landscape than the feature that was modeled – route was above scoured channel or debris slide was not 

active. To adjust the model would require field verification and remapping of the ephemeral stream layer 

and more accurate mapping of location and level of activity of debris slide features across the Forest. The 

model was not adjusted in this project. Until adjusted the modeled risk is still useful as general a risk 

assessment because it still assesses the relative potential risk of soil erosion in a road and motorized trailrelated disturbed environment on the TNF.

Existing Cross Country Travel

Currently cross country travel occurs on 717,900 acres on the TNF. Cross country travel is prohibited on 

86,500 acres due to existing closures. In most years there are site specific issues that occur due to cross 

country travel somewhere on the Forest. The effects of these disturbances are usually dealt with by 

Ranger District recreation and watershed staff.

Cross country travel has resulted in 868.7 miles of motorized trails unauthorized for motorized use on 

the TNF and another 829.6 miles of closed NFTS roads that are still receiving some motorized use. As 

discussed below in the inventory results section, some routes are stable and others need 

maintenance/mitigation (For route-specific resource information see Appendix A, Site Specific Road, 

Trail and Open Area Information).

Field Survey Green, Yellow, Red (GYR) Motorized Trail Condition Ratings

Field surveys were completed for approximately 100 miles of authorized and unauthorized motorized 

trails using the Green-Yellow-Red (GYR) OHV Trail Condition Rating protocol. This data is summarized 

by route in Appendix A, Site Specific Road, Trail and Open Area Information. Stream crossings were 

evaluated using the GYR protocol and R-5 Best Management Practices Evaluation Protocol (BMPEP) 

(USDA Forest Service, 2000). The GYR protocol uses factors, such as water control, erosion off-trail, 

tread wear, tread width, and crossing data to rate route conditions. Motorized trails were broken into 
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Tahoe National Forest – 103

segments in the field based on site conditions. The GYR Trail condition rating form was used to rate each 

motorized trail segment. A motorized trail segment was defined as a portion of trail that has similar 

resource impacts. The Green condition class means that erosion and runoff water control on the trail 

surface is functioning properly. The Yellow condition class means erosion and runoff water control on the 

trail surface is presently functioning but needs maintenance soon or it could deteriorate and become red 

condition class. The Red condition class means erosion and runoff water control on the trail surface is not 

functioning, is causing watershed impacts and should be given highest priority for maintenance and 

repair. The R-5 BMPEP protocol looks at erosion on route, sediment movement on route and off, 

route/stream crossings, etc. Many of these trails show impacts caused by wet season use (e.g., rutting, 

widening of routes around wet spots, channelized water movement, etc.). 

Table 3.02-9 shows that approximately 85 percent of the inventoried routes are in Green condition 

class; 4 percent are in the Yellow condition class; 1 percent are in the in Red condition class; and 11

percent are overgrown and have begun recovery. Additional erosion and runoff water control is still 

needed on a portion of the routes, especially the route segments in the Yellow and Red condition classes.

Table 3.02-9. Percent of Inventoried Routes by Route Condition Class

Inventoried Routes Green

Condition Class

Yellow

Condition Class

Red

Condition Class

Overgrown 

Route

Percent In Condition Class 85% 4% 1% 11%

Note: numbers may not add up to 100% due to rounding.

Existing Seasonal Closures

The condition of native surface roads and motorized trails can quickly decline during winter or wet 

weather use due to rutting. Rutting is the process where soils are displaced and deform to the shape of the 

tire tracks that make their way through saturated soils. Rutting makes the route more susceptible to 

damage in the spring as the area begins to dry out. Rutting can occur if traffic enters the area before the 

soils have sufficient drying time. To some extent wet season damage can be influenced by soil type, but 

all soil types are susceptible damage due to wet season use. Native surface roads and motorized trails are 

most susceptible to damage by motor vehicles when wet. Currently there are approximately 3,400 miles

of NFTS native surface roads and motorized trails that are open year round. There are 231 miles of roads 

and motorized trails closed seasonally. The areas that are seasonally closed for wildlife also function to 

reduce wet season damage to routes, soils, and watershed resources.

Environmental Consequences: Soil Resources

The primary changes considered in this analysis are the prohibition of cross country travel, changes in 

miles of motorized use on existing roads and trails, and changes in class of vehicle or season of use. 

Continued cross country motorized vehicle travel can increase the area of soil disturbance and loss of 

productivity. Some of the motorized trails unauthorized for motorized use, being considered for addition 

to the NFTS, are native surface trails that currently exist on the ground. The hydrologic footprint of these
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104 – Tahoe National Forest

trails already exists. The routes where negative effects on soil resources are most likely to occur are: 

native surface NFTS roads and motorized trails, motorized trails unauthorized for motorized use and nonprivate roads (with native surface) within the TNF boundary.

Direct and Indirect Effects to Soil Resources

Direct impacts to soils that result from this project are limited. There are no new ground disturbing 

activities proposed with this project. The roads and trails being evaluated in this analysis already exist on 

the ground, but may require upgrading to NFTS standards as well as periodic maintenance. They are

generally compacted and lack vegetative cover. Runoff from the surface is collected and discharged as 

potentially erosive flows at points below the route. Some are eroded or causing erosion, others are stable 

and are not causing any negative resource impacts. From the standpoint of soil productivity and growing 

vegetation, these routes are already non-productive. Therefore, on these roads and trails the potential 

effects on soil resources are related to controlling runoff water to prevent concentrated water flow and 

subsequent erosion and sediment production and movement and protecting soils downslope from the 

routes from runoff and gully erosion. It should be noted that most roads and motorized trails on the TNF 

have some site specific risk to soil and water resources. Many of these risks have been or can be 

mitigated.

All alternatives would have indirect effects on soil and watershed resources, but they vary by 

alternative. Route designation would indirectly affect soil erosion and subsequent sediment delivery to 

streams to the extent that activities resulting from designation or closure (1) affect the amount of traffic 

and season of use on routes; (2) designate routes in areas with highly erosive soils; (3) affect levels of 

maintenance; and (4) affect the potential for recovery and restoration.

Route Recovery

None of the proposed alternatives includes decommissioning or restoration for motorized trails not 

designated for motorized use. Based on observations of the TNF watershed and vegetation management 

staff, approximately 75 percent of the routes should recover passively over the 20 to 30 years after 

motorized use stops. 

The degree of recovery will be dependent upon many factors. Without adequate drainage, some trails 

could continue to erode even if they could be effectively closed. Other motorized trails not designated for 

motorized use would most likely start to recover due to ingrowth of shrubs and other plants from the 

edges and slowly close in to some extent. Some would be used by non-motorized users (mountain bikes, 

equestrian, and hikers) and would probably remain on the ground in some form. If use of the route ceases, 

in the short term (five years or less), some native vegetation may establish on routes that have little soil 

compaction. It is likely that routes with moderate soil compaction (within the wheel tracks) would take 

between 5 and 20 years to vegetatively recover (develop native forb or shrub cover). The most severely 

disturbed sites are not likely to recover without some type of active restoration. The disposition of 

motorized trails unauthorized for motorized use that are not added to the system would be dealt with in 

future NEPA documents.
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Tahoe National Forest – 105

Projected Effects on Soils on the Tahoe National Forest

Projected Soil Erosion Risk Assessment Based on Erosion Hazard Ratings from the Tahoe National 

Forest Soil Resource Inventory

Maps of currently authorized and unauthorized routes were overlaid on the soil resource inventory map in 

GIS. The miles of routes were summarized by erosion hazard rating and by alternative. Table 3.02-10

shows the miles of higher risk routes (native surface, motorized routes) by erosion hazard and alternative. 

It also shows the change from the existing condition if any of the action alternatives are implemented.
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106 – Tahoe National Forest

Table 3.02-10. Native surface road and motorized trails (high risk routes) by Erosion Hazard Rating

Erosion Hazard 

Rating

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

National Forest 

Transportation System 

(miles)

Very High 96 125 96 96 135 99 97

High 1,331 1,682 1,331 1,356 1,759 1,498 1,364

Moderate 337 413 337 341 439 372 343

N/A1 11 15 11 12 15 13 13

Unauthorized Routes 

(miles)

Very High 111 0 0 0 0 0 0

High 1272 0 0 0 0 0 0

Moderate 290 0 0 0 0 0 0

N/A1 21 0 0 0 0 0 0

Private Roads (miles) Very High 80 80 80 80 80 80 80

High 1,293 1,293 1,293 1,293 1,293 1,293 1,293

Moderate 415 415 415 415 415 415 415

N/A1 27 27 27 27 27 27 27

Total (miles) Very High 287 205 176 176 215 179 177

High 3,896 2,975 2,624 2,649 3,054 2,791 2,657

Moderate 1,042 828 752 759 854 787 758

N/A1 59 42 38 39 42 40 40

Change from Current 

(percent remaining)

Very High 71% 61% 61% 75% 62% 62%

High 76% 67% 68% 78% 72% 68%

Moderate 79% 72% 73% 82% 76% 73%

N/A1 81% 64% 55% 71% 68% 68%

1 Includes areas such as rock outcroppings
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Environmental Consequences by Alternative

See the effects methodology section above regarding how this analysis was conducted.

Alternative 1 – No action

• Prohibition of cross country motor vehicle travel: Cross country travel would continue in 

Alternative 1 on 717,900 acres on the TNF. Cross country travel would continue to be prohibited 

on 86,500 acres. It is likely that cross county travel would result in an increase in the motorized 

footprint on the TNF. Cross country motor vehicle travel would continue on 868.7 miles of 

motorized trails unauthorized for motorized use on the TNF and another 829.6 miles of closed 

NFTS roads that are still receiving some motorized use. This could impact soil resources by 

increasing erosion which would decrease long-term soil productivity.

• Additions to the NFTS. There are no additions of unauthorized roads or trails under this 

alternative.

• Changes to the existing NFTS. There are no changes to vehicle class and/or season of use to the 

NFTS under this alternative. No Maintenance Level (ML) 1 roads are reopened with this 

alternative. However, cross country motorized use is allowed, so the net effect would be that use 

of some ML 1 routes would occur.

• Forest Plan Amendment: There are no changes to the Forest Plan with this alternative.

• Cumulative Effects 

 There would be 717,900 acres open to cross country motor vehicle travel.

 There are approximately 868.7 miles of motorized trails unauthorized for motorized use on the 

TNF and another 829.6 miles of closed NFTS roads that are still receiving some motorized use

 There are 5,293.8 miles of native surface roads and motorized trails on the TNF (EHRs are 

displayed in Table 3.02-10.). 

 The Equivalent Roaded Acres (ERAs) in acres associated with the current motorized footprint 

are 16,030.0.

Alternative 2 – Increased Motorized Recreation and Access Opportunities

• Prohibition of cross country motor vehicle travel: Cross country motor vehicle travel would be 

prohibited on 833,392 acres which would reduce the mileage available for motorized use by 809.1 

miles of unauthorized routes and 829.6 miles of ML 1 roads currently receiving unauthorized use. 

This would prohibit the proliferation of new routes and prohibit motorized use on all unauthorized 

routes not added to the NFTS. In the long-term (20 years) this could reduce erosion associated 

with motorized use on the TNF.

• Additions to the NFTS. Adding 5.0 miles of unauthorized roads and 54.6 miles of unauthorized 

trails to the NFTS would have minimal effects to soil resources. These are pre-existing routes so 

the loss of productivity has already occurred. These route additions would be subject to FS 

standards.
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108 – Tahoe National Forest

• Changes to the existing NFTS.

 Change Vehicle Classes through Mixed Use: Approving mixed use on 241.5 miles would not 

affect soil resources.

 Change Vehicle Classes through Maintenance Levels (ML): Changing vehicle class on 

157.2 miles, to allow licensed operators of non-highway legal vehicles to operate on NFS roads 

where such use is currently prohibited through the conversion of ML 3 roads to ML 2, would 

have minimal effects to soil resources. These are pre-existing routes so the loss of productivity 

has already occurred. As designated routes within the NFTS these routes would be subject to 

FS standards.

 Changes in Seasonal Restrictions: Seasonal restrictions for deer winter range would be lifted 

on 10.5 miles of roads resulting from the Forest Plan Amendment to Management Area 84 

(Humbug-Sailor) which would slightly increase the risk of wet season damage to these roads 

and adjacent soils.

 Reopening Maintenance Level 1 Roads: No ML 1 roads would be opened to motorized use.

• Forest Plan Amendment: The Tahoe National Forest Land and Resource Management Plan 

(LRMP) would be amended to remove the November 1 to May 1 seasonal closure in the Sugar 

Pine area (Management Area 84 Humbug Sailor) on key winter deer range to improve motorized 

recreation opportunities. The Forest Plan Amendment has the same as effects as Seasonal 

Restrictions above.

• Cumulative Effects: The short-term effects of Alternative 2 would be minimal. The long-term 

cumulative effects of Alternative 2 would decrease the NFTS soil hydrologic footprint and effects 

to long-term soil productivity. 

 There would be approximately 2,700 acres of cross country motor vehicle travel in established

“Open Areas.”

 There would be 59.6 miles of unauthorized routes added to NFTS. 

 There would be 3,812.3 miles of native surface roads and motorized trails on the TNF. 

 The ERAs associated with the NFTS would be 13,253.7.

Alternative 3 – Cross country Travel Prohibition Only – No Changes to the 

Existing National Forest Transportation System

• Prohibition of cross country motor vehicle travel: Public wheeled motor vehicle travel off 

designated NFTS roads, NFTS trails, and outside established motorized use areas would be 

prohibited, except as allowed by permit or other authorization on 836,000 acres which would 

reduce the mileage available for motorized use by 868.7 miles of unauthorized routes and 829.6 

miles of ML1 roads currently receiving unauthorized use. This would stop the proliferation of new 

routes and prohibit motorized use on all unauthorized routes not added to the NFTS. This could 

reduce erosion associated with motorized use on the TNF.

• Additions to the NFTS. No unauthorized routes would be added to the NFTS as roads or 

motorized trails under this alternative
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Tahoe National Forest – 109

• Changes to the existing NFTS - this includes changing the vehicle class and/or season of use 

and reopening Maintenance Level 1 Roads. No Changes to the NFTS would be made in this 

alternative.

• Forest Plan Amendment No amendments would be made to the Forest Plan.

• Cumulative Effects: The short-term effects of Alternative 3 would be minimal. The long-term 

cumulative effects of Alternative 3 would decrease the NFTS soil hydrologic footprint and effects 

to long-term soil productivity.

 There would be 0 acres of cross country motor vehicle. 

 There would be 0 miles of unauthorized routes added to NFTS.

 There would be 3,595.6 miles of native surface roads and motorized trails on the TNF. 

 The ERAs associated with the NFTS would be 13,180.

Alternative 4 – Increased Resource Protection

• Prohibition of cross country motor vehicle travel: Public wheeled motor vehicle travel off 

designated NFTS roads, NFTS trails, and outside established motorized use areas would be 

prohibited, except as allowed by permit or other authorization on 836,000 acres which would 

reduce the mileage available for motorized use by 842.4 miles of unauthorized routes and 829.5 

miles of ML 1 roads currently receiving unauthorized use. This would stop the proliferation of 

new routes and prohibit motorized use on all unauthorized routes not added to the NFTS. This 

could reduce erosion associated with motorized use on the TNF.

• Additions to the NFTS. Adding 3.7 miles of roads and 22.6 miles of trails to the NFTS would

have minimal effects to soil resources. These are pre-existing routes so the loss of productivity has 

already occurred. These route additions would be subject to FS standards.

• Changes to the existing NFTS.

 Change Vehicle Classes through Mixed Use: No changes would be made to allow licensed 

operators of non-highway legal vehicles to operate on NFTS roads where such use is currently 

prohibited through approval of mixed use.

 Change Vehicle Classes through Maintenance Levels: Changing vehicle class on 3.4 miles,

to allow operators of non-highway legal vehicles to operate on NFTS roads where such use is 

currently prohibited through the conversion of ML 3 roads to ML 2, would have minimal 

effects to soil resources. These are pre-existing routes so the loss of productivity has already 

occurred. As designated routes within the NFTS these routes would be subject to FS standards.

 Changes in Seasonal Restrictions: Wet weather seasonal closures from January 1 to May 31 

in the Burlington area and January 1 to April 30 on the remainder of the Forest on native 

surface roads and motorized trails would be added to minimize erosion and protect water 

quality. A total of 1,312.1 total miles would have changes in seasonal restrictions. Seasonal 

restrictions would decrease the risk of increased erosion associated with wet season route 

damage due to motorized use.
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110 – Tahoe National Forest

 Reopening Maintenance Level 1 Roads: One ML 1 road (0.1 miles) would be reopened to 

motorized use. Reopening 0.1 miles of ML 1 road would not affect long-term soil productivity. 

Closed NFTS routes that are proposed to be opened are roads that were engineered to control 

drainage and erosion. They are expected to receive maintenance when opened.

• Forest Plan Amendment: No amendments would be made to the Forest Plan.

• Cumulative Effects: The short-term cumulative effects of Alternative 4 would be minimal. The 

long-term cumulative effects of Alternative 4 would decrease the NFTS soil hydrologic footprint 

and effects to long-term soil productivity.

 There would be 0 acres of cross country motor vehicle travel.

 There would be 26.3 miles of unauthorized routes added to NFTS.

 There would be 3,625.3 miles of native surface roads and motorized trails on the TNF. 

 The ERAs associated with the NFTS would be 13,353.7.

Alternative 5 – Increased Motorized Recreation Access plus Reopening 

Maintenance Level 1 and Temporary Roads

• Prohibition of cross country motor vehicle travel: Public wheeled motor vehicle travel off 

designated NFTS roads, NFTS trails, and outside established motorized use areas would be 

prohibited, except as allowed by permit or other authorization on 836,000 acres which would 

reduce the mileage available for motorized use by 788.3 miles of unauthorized routes and 736.2 

miles of ML 1 roads currently receiving unauthorized use. This would stop the proliferation of 

new routes and prohibit motorized use on all unauthorized routes not added to the NFTS. This 

could reduce erosion associated with motorized use on the TNF.

• Additions to the NFTS. Adding 5.0 miles of roads and 75.4 miles of trails to the NFTS would

have minimal effects to soil resources. These are pre-existing routes so the loss of productivity has 

already occurred. These route additions would be subject to FS standards.

• Changes to the existing NFTS.

 Change Vehicle Classes through Mixed Use: Changing vehicle class on 241.5 miles to allow 

licensed operators of non-highway legal vehicles to operate on NFTS roads where such use is 

currently prohibited through approval of mixed use would not affect soil resources.

 Change Vehicle Classes through Maintenance Levels: Changing vehicle class on 157.2

miles, to allow operators of non-highway legal vehicles to operate on NFTS roads where such 

use is currently prohibited through the conversion of ML 3 roads to ML 2, would have minimal 

effects to soil resources. These are pre-existing routes so the loss of productivity has already 

occurred. As designated routes within the NFTS these routes would be subject to FS standards.

 Changes in Seasonal Restrictions: Wet weather seasonal closures from January 1 to May 31 

in the Burlington area and January 1 to April 30 on the remainder of the Forest on native 

surface roads and motorized trails would be added to minimize erosion and protect water 

quality. A total of 1,396.7 total miles would have changes in seasonal restrictions.

 Reopening Maintenance Level 1 Roads: 113 ML 1 roads (93.4 miles) would be reopened to 

motorized use. Reopening ML 1 roads would have a small effect on long-term soil productivity 
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Tahoe National Forest – 111

where the routes are reopened. Closed NFTS routes that are proposed to be opened are roads 

that were engineered to control drainage and erosion. They are expected to receive

maintenance when opened.

• Forest Plan Amendment: The Tahoe National Forest Land and Resource Management Plan 

(LRMP) would be amended to remove the November 1 to May 1 seasonal closure in the Sugar 

Pine area (Management Area 84 Humbug Sailor) on key winter deer range to improve motorized 

recreation opportunities. The Forest Plan Amendment has the same as effects as Seasonal 

Restrictions above.

• Cumulative Effects: The short-term cumulative effects of Alternative 5 would be minimal. The 

long-term cumulative effects of Alternative 5 would decrease the NFTS soil hydrologic footprint 

and effects to long-term soil productivity.

 There would be 0 acres of cross country motor vehicle travel.

 There would be 80.4 miles of unauthorized routes added to NFTS.

 There would be 3,926.5 miles of native surface roads and motorized trails on the TNF. 

 The ERAs associated with the NFTS would be 13,446.

Alternative 6 – Preferred Alternative Motorized Access and Resource Protection

• Prohibition of cross country motor vehicle travel: Public wheeled motor vehicle travel off 

designated NFTS roads, NFTS trails, and outside established motorized use areas would be 

prohibited, except as allowed by permit or other authorization on 835,800 acres which would 

reduce the mileage available for motorized use by 807.3 miles of unauthorized routes and 818.2 

miles of ML 1 roads currently receiving unauthorized use. This would stop the proliferation of 

new routes and prohibit motorized use on all unauthorized routes not added to the NFTS. This 

could reduce erosion associated with motorized use on the TNF.

• Additions to the NFTS. Adding 13.1 miles of roads and 48.3 miles of trails to the NFTS would

have minimal effects to soil resources. These are pre-existing routes so the loss of productivity has 

already occurred. These route additions would be subject to FS standards.

• Changes to the existing NFTS.

 Change Vehicle Classes through Mixed Use: Changing vehicle class on 130.8 miles to allow 

licensed operators of non-highway legal vehicles to operate on NFTS roads where such use is 

currently prohibited through approval of mixed use would not affect soil resources.

 Change Vehicle Classes through Maintenance Levels: Changing vehicle class on 122.0

miles, to allow operators of non-highway legal vehicles to operate on NFTS roads where such 

use is currently prohibited through the conversion of ML 3 roads to ML 2, would have minimal 

effects to soil resources. These are pre-existing routes so the loss of productivity has already 

occurred. As designated routes within the NFTS these routes would be subject to FS standards.

 Changes in Seasonal Restrictions: Wet weather seasonal closures from January 1 to May 31 

in the Burlington area and January 1 to April 30 on the remainder of the Forest on native 

surface roads and motorized trails would be added to minimize erosion and protect water 
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112 – Tahoe National Forest

quality. In addition, over the snow travel would be permitted on 3.6 miles of the Fordyce Jeep 

trail when 15 inches of snow is present on the ground, which prevents soil disturbance. A total 

of 1,396.7 total miles would have changes in seasonal restrictions.

 Reopening Maintenance Level 1 Roads: Thirteen ML 1 roads (11.4 miles) would be reopened 

to motorized use. Reopening 11.4 miles of ML 1 roads would have a small affect on long-term 

soil productivity where the routes are reopened. Closed NFTS routes that are proposed to be 

opened are roads that were engineered to control drainage and erosion. They are expected to 

receive maintenance when opened.

• Forest Plan Amendment: The Tahoe National Forest Land and Resource Management Plan 

(LRMP) would be amended to remove the November 1 to May 1 seasonal closure in the Sugar 

Pine area (Management Area 84 Humbug Sailor) on key winter deer range to improve motorized 

recreation opportunities. The Forest Plan Amendment has the same as effects as Seasonal 

Restrictions above.

• Cumulative Effects: The short-term cumulative effects of Alternative 6 would be minimal. The 

long-term cumulative effects of Alternative 6 would decrease the NFTS soil hydrologic footprint 

and effects to long –term soil productivity.

 There would be 244 acres of cross country motor vehicle travel in established “Open Areas”

 There would be 61.4 miles of unauthorized routes added to NFTS.

 There would be 3,790.3 miles of native surface roads and motorized trails on the TNF. 

 The ERAs associated with the NFTS would be 13,276.

Alternative 7 – Proposed Action as Identified in Notice of Intent (NOI)

• Prohibition of cross country motor vehicle travel: Public wheeled motor vehicle travel off 

designated NFTS roads, NFTS trails, and outside established motorized use areas would be 

prohibited, except as allowed by permit or other authorization on 836,000 acres which would 

reduce the mileage available for motorized use by 832.0 miles of unauthorized routes and 828.5 

miles of ML1 roads currently receiving unauthorized use. This would stop the proliferation of new 

routes and prohibit motorized use on all unauthorized routes not added to the NFTS. This could 

reduce erosion associated with motorized use on the TNF.

• Additions to the NFTS. Adding 36.7 miles of trails to the NFTS would have minimal effects to 

soil resources. These are pre-existing routes, so the loss of productivity has already occurred.

These route additions would be subject to FS standards.

• Changes to the existing NFTS.

 Change Vehicle Classes through Mixed Use: No changes would be made to allow licensed 

operators of non-highway legal vehicles to operate on NFTS roads where such use is currently 

prohibited through approval of mixed use.

 Change Vehicle Classes through Maintenance Levels: Changing vehicle class on 3.4 miles,

to allow operators of non-highway legal vehicles to operate on NFTS roads where such use is 

currently prohibited through the conversion of ML 3 roads to ML 2, would have minimal 
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Tahoe National Forest – 113

effects to soil resources. These are pre-existing routes so the loss of productivity has already 

occurred. As designated routes within the NFTS these routes would be subject to FS standards.

 Changes in Seasonal Restrictions: No changes in seasonal restrictions would be made.

 Reopening Maintenance Level 1 Roads: Two ML 1 roads (1.1 miles) would be reopened to 

motorized use. Route opening may have a minor effect on soil erosion but would be less in 

relation to construction of new routes. Closed NFTS routes that are proposed to be opened are 

roads that were engineered to control drainage and erosion. They are expected to receive

maintenance when opened.

• Forest Plan Amendment: No amendments would be made to the Forest Plan.

• Cumulative Effects: The short-term cumulative effects of Alternative 7 would be minimal. The 

long-term cumulative effects of Alternative 7 would decrease the NFTS soil hydrologic footprint 

and effects to long-term soil productivity.

 There would be 0 acres of cross country motor vehicle travel.

 There would be 36.7 miles of unauthorized routes added to NFTS.

 There would be 3,636.7 miles of native surface roads and motorized trails on the TNF.

 The ERAs associated with the NFTS would be 13,220.

Summary of Effects Analysis across All Alternatives

Table 3.02-11. Comparison of Effects to the Soil Resource

Indicators – Soil Resource Rankings of Alternatives for Each Indicator1

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Prohibition on Cross County Travel 1 2 4 4 4 3 4

Miles of unauthorized routes displayed by miles

-relative ranking

1 NA NA NA NA NA NA

Miles of NFTS native surface roads and 

motorized trails 

1 3 7 6 2 4 5

Miles of native surface roads and motorized

trails displayed by miles in each of the R-5 EHR 

ratings – VH, H, M

1 3 7 6 2 4 5

Seasonal Restrictions miles of routes 2 1 2 5 7 6 2

Cumulative effects on soil productivity from 

unauthorized use (ERAs)

1 4 7 6 2 3 5

Total for Soil Resource 1.2 2.4 5.4 5.4 3.4 4.0 4.2

1 A score of 7 indicates the alternative has the least impact for the soil resource related to the indicator; A score of 1 indicates the 

alternative has the most impact for the soil resource related to the indicator.

Using the metrics from Table 3.02-11, Alternative 1 would have the highest potential impacts to soil 

resources, followed in order by Alternative 2, Alternative 5, Alternative 6, Alternative 7, Alternative 4, 

and Alternative 3.
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114 – Tahoe National Forest

Hydrology _____________________________________________

Introduction

Protection of water quantity and quality is an important part of the mission of the Forest Service (Forest 

Service Strategic Plan for 2007 to 2012, July 2007). Management activities on National Forest System 

(NFS) lands must be planned and implemented to protect the hydrologic functions of forest watersheds, 

including the volume, timing, and quality of streamflow. The use of roads, trails, and other areas on 

national forests for public operation of motor vehicles has potential to affect these hydrologic functions 

through interception of runoff, compaction of soils, and detachment of sediment (e.g., Foltz, 2006).

Management decisions to eliminate cross-county motor vehicle travel, add new routes and areas to the 

NFTS, and make changes to the existing NFTS must consider effects on watershed functions.

Meadows and aquatic species are included in the analysis of hydrologically sensitive areas in this 

section and in Terrestrial and Aquatic Species (Chapter 3.03), Plant Communities (Chapter 3.06), and 

Appendix R (Riparian Conservation Objectives Analysis)

Analysis Framework: Statute, Regulation, Forest Plan,

and Other Direction

Direction relevant to the proposed action as it affects water resources includes:

• Clean Water Act of 1948 (as amended in 1972 and 1987) establishes as federal policy the 

control of point and non-point pollution and assigns the States the primary responsibility for 

control of water pollution. Compliance with the Clean Water Act by national forests in California 

is achieved under state law (see below).

• Non-point source pollution on national forests is managed through the Regional Water 

Quality Management Plan (USDA Forest Service, Pacific Southwest Region, 2000), which 

relies on implementation of prescribed Best Management Practices (BMPs). The Water Quality 

Management Plan includes one BMP for OHV use (4-7) and 28 BMPs related to road construction 

and maintenance (2-1 to 2-28) (See Appendix F, Watershed Analysis). All NFTS roads and trails 

open to motorized use are required to comply with these BMPs. Of particular relevance for motor 

vehicle travel management, BMP 4-7 requires each forest to: (1) identify areas or routes where 

OHV use could cause degradation of water quality, (2) identify appropriate mitigation and 

controls, and (3) restrict OHV use to designated routes. This BMP further requires forests to take 

immediate corrective actions if considerable adverse effects are occurring or are likely to occur.

• The California Water Code consists of a comprehensive body of law that incorporates all state 

laws related to water, including water rights, water developments, and water quality. The laws 

related to water quality (sections 13000 to 13485) apply to waters on the national forests and are 

directed at protecting the beneficial uses of water. Of particular relevance for the proposed action 

is section 13369, which deals with nonpoint-source pollution and best management practices.

• The Porter-Cologne Water-Quality Act, as amended in 2006, is included in the California Water 

Code. This act provides for the protection of water quality by the State Water Resources Control 
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Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

Tahoe National Forest – 115

Board and the Regional Water Quality Control Boards, which are authorized by the U.S. 

Environmental Protection Agency to enforce the Clean Water Act in California.

• The Sierra Nevada Forest Plan Amendment (SNFPA). The Record of Decision (ROD) for the 

2004 SNFPA includes standards and guidelines (S&Gs) that apply to the 10 Sierran forests for 

construction and relocation of roads and for management of riparian conservation areas (RCAs).

These standards and guidelines require the Forest Service to avoid road construction, 

reconstruction, and relocation in meadows and wetlands (SNFPA S&G 70). Reconstructing 

unauthorized routes to bring them to NFTS standards in meadows or wetlands should therefore be 

avoided. Only routes that already meet NFTS standards in meadows and wetlands should be 

proposed for addition to the NFTS. SNFPA S&G 92 requires that the Forest Service evaluate new 

management activities within RCAs and Critical Aquatic Refuges (CARs) during environmental 

analysis to determine consistency with Riparian Conservation Objectives (RCOs) at the project 

level and the Aquatic Management Strategy (AMS) goals for the landscape. Adding an 

unauthorized route to the NFTS is a new management activity and must comply with S&G 92. 

SNFPA S&G 100 requires the Forest Service to maintain and restore the hydrologic connectivity 

of streams, meadows, and wetlands by identifying roads and trails that intercept, divert, or disrupt 

flows paths and implement corrective actions. SNFPA S&G 102 requires that the Forest Service 

determine if stream characteristics are within the range of natural variability prior to taking actions 

that could adversely affect streams.

Water Quality Protection (TNF LRMP, pg. V-35). Use Best Management Practices (BMPs) to 

meet water quality objectives and maintain and improve the quality of surface water on the 

Forest. Best Management Practices (BMPs) are implemented as mitigation measures specified in 

Appendix A (Road Cards) for any motorized trail to be added to the National Forest 

Transportation or any lands to be established as “Open Areas.” These mitigation measures will 

meet water quality objectives and maintain and improve the quality of surface water on the 

Forest.

Effects Analysis Methodology

This is a site specific project, for which there is two levels of analysis. First, there is site-specific analysis 

of the individual routes proposed for addition to the NFTS. This detailed analysis is by route and is 

included in an Appendix A (Site Specific Road, Trail and Open Area Information) and the project record.

Second, there is the analysis of each alternative as a whole, which is informed by the site-specific 

route analysis noted above and other information. The discussion of the direct, indirect, and cumulative 

effects of each alternative is in a summary form. For ease of documentation and understanding, the effects 

of the alternatives are described separately for five discreet actions and then combined to provide the total 

direct and indirect effects of each alternative (see below). The combination of these discreet actions is 

then added to the past, present, and reasonably foreseeable actions in the cumulative effects analysis. The 

five discreet actions common to all action alternatives are: (1) The prohibition of cross country motor 

vehicle travel; (2) The addition of facilities (unauthorized roads and trails) to the NFTS, including 
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116 – Tahoe National Forest

identifying seasons of use and vehicle class; (3) The establishment of Motorized “Open Areas”; (4) 

Changes to the existing NFTS (which includes: change in Class of Vehicles resulting from approval of 

mixed use, change in Class of Vehicle resulting from changes in maintenance levels, change in Season of 

Use, and reopening ML 1 roads to motorized use); and (5) Amendments to the Forest Plan. This 

discussion is the focus of this Effects Analysis Methodology section. 

The Effects Analysis Methodology section describes the methodology used for the effects analysis in 

Chapter 3, not the site-specific analysis of each route. It addresses impacts relevant to the hydrology

resource, hydrology resource-specific assumptions, hydrology resource indicators to be measured, 

including justification as to why they were chosen, sources of information used to support the analysis, 

timeframes (short term and long term), and spatial boundary of the effects analysis. 

The Effects Analysis Methodology focuses on the assumptions, methodology, and indicators for 

addressing the direct and indirect effects of each of the five actions and the cumulative effects of 

implementing the alternative as a whole. The conclusions of the analysis in the Environmental 

Consequences section present the direct and indirect effects of implementing the alternative as a whole 

addressing the effects of each of the five proposed actions. Then, the cumulative effects of implementing 

each alternative (the direct and indirect effects of this action in combination with the effects of past, 

present, and reasonably foreseeable future actions) are displayed.

The cumulative effects analysis considers all roads and motorized trails including private on the TNF.

This analysis focuses on native surface (dirt) roads and motorized trails for direct and indirect effects 

analysis. 

Impacts relevant to water resources include

• Modification of surface-water runoff timing and magnitude owing to interception of surface and 

subsurface runoff by routes during rainfall and snowmelt.

• Increased erosion of route surfaces, hillslopes, and channels, with consequent increases in fluvial 

loads of sediment and sediment-related pollutants such as nutrients, heavy metals, and pesticides.

• New NFTS roads and trails that traverse hydrologic features such as streams and wet meadows 

and cross riparian conservation areas and other designated riparian buffers that are protected from 

disturbance by forest LRMPs and SNFPA Standards and Guidelines.

Assumptions specific to the water resources analysis

• Adverse effects of route use by motor vehicles include long-term damage to soil and water 

resources owing to soil compaction, alteration of drainage patterns, and destruction of vegetation. 

• Without active restoration, these effects would persist for periods of years to decades (20-30 years) 

following prohibition of public motor vehicle use in the Tahoe National Forest.

• Sediment production from motor vehicle use of native-surface NFTS routes is increased by higher 

levels of traffic and is reduced by maintenance of road drainage features (culverts, waterbars, and 

ditches).
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Tahoe National Forest – 117

• Spatial boundary for the effects analysis is the forest boundary. Within the forest boundary, 

specific areas that are analyzed include hydrologically sensitive areas, inventoried unauthorized 

routes, and NFTS routes for which changes in season of use or vehicle class are proposed.

Cumulative watershed effects are analyzed for HUC 6 watersheds.

• Hydrologically sensitive areas include all designated riparian protection areas, such as riparian 

conservation areas. All areas of perennial and seasonal standing or running surface water and areas 

of perennially or seasonally saturated soil are included. Examples of hydrologically sensitive areas 

include streams, lakes, reservoirs, fens, wet meadows, marshes, and unstable hill slopes.

Hydrologically sensitive areas will be referred to as RCAs in this document.

Data Sources

• Route-specific data collected in the field using established protocols for road erosion inventories 

or OHV green-yellow-red inventories.

• GIS analyses of route miles and stream crossings in hydrologically sensitive areas.

• Hydrologic data collected by the forest or other agencies, such as United States Geographical 

Survey (USGS), Environmental Protection Agency (EPA), and California Department of Fish and 

Game (CDF&G), on streamflow, sediment loads, and stream biota and habitat.

• Air and ground photos and anecdotal information documenting the time required for passive 

restoration of routes closed to motor vehicle traffic (recovery time may vary based on 

precipitation, elevation, aspect, and other factors (See Soil Resources).

Water Resources Indicators 

• Miles of unauthorized routes in RCAs.

• Sum of routes proposed for addition to the NFTS in RCAs on the forest.

• Acres of “Open Areas” in RCAs.

• Numbers of locations where routes divert or have potential to divert streamflow. (All stream 

crossings were assumed to have potential to divert streamflow.)

• Miles of ML 1 routes receiving unauthorized motorized use in RCAs.

• Sum of route miles with documented erosional features.

• Miles of routes with proposed changes in vehicle class and/or season of use in RCAs.

• Landscape Erosion Risk (HUC6 watershed) - Density of native surface roads and motorized trails 

and EMDS erosion risks class.

• Route-related Equivalent Road Areas (ERAs) in acres (cumulative effects).

Water Resources Methodology by Action: 

1) Direct/indirect effects of the prohibition of cross country motor vehicle travel

Considerations: The major effects of cross country motor vehicle travel and route proliferation on water 

resources include increased peak flows and sediment loads due to compacted and unvegetated route 

surfaces and detachment of sediment by vehicles. The effect of the prohibition of cross country motor 
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118 – Tahoe National Forest

vehicle travel would be to end traffic on routes and areas beyond the authorized NFTS. In the short term,

the unauthorized routes and areas disturbed by motor-vehicle use would not change much because 

removal of vegetation, compaction of soils, and alteration of drainage patterns require time to heal 

without active restoration. Elimination of traffic on unauthorized routes and areas would reduce erosion, 

but the routes would still intercept and concentrate surface flows and produce sediment. In the long term, 

some or all unauthorized routes and areas would probably revegetate and regain some of their hydrologic 

and geomorphic functions, although use of these routes by non-motorized vehicle traffic could delay or 

prevent recovery

Short-term timeframe: 1 year.

Long-term timeframe: The period used for long-term effects analysis is 20 to 30 years. This is a 

reasonable timeframe to think about and predict the expected vegetative recovery (and reduction in 

erosion) for areas disturbed by unauthorized use. The personal observations of the watershed staff (20-30 

years experience on the TNF) support this recovery period. This is also the same recovery period used for 

the Cumulative Soil Effects analysis in this document.

Spatial boundary: Major River Basins and Sub-basins and The Forest Boundary.

Indicator(s): Miles of unauthorized routes in RCAs.

Methodology: GIS analysis of existing unauthorized routes in Riparian Conservation Areas (RCAs).

Compare no-action to action alternatives, and compare all alternatives to regulatory framework.

Rationale: Published studies (see Reference section) have documented that erosion of native-surface 

roads is increased by traffic.

In a study of cross country ATV impacts, Foltz and Meadows (2007) looked at the degree of 

disturbance based on leaf litter and vegetation cover, trail width (both tread and displaced material) and 

ATV rut depth. Tests showed that 40 to 120 passes of an ATV along a cross country route could result in 

what they called “high” disturbance (i.e., >60 percent loss of ground cover, trail width of greater than 72 

inches, and ruts exceeding 6 inches in depth). The study concludes that ATV traffic adversely affects 

natural resources, and that all of the vehicles tested contributed to those effects regardless of the type of 

ATV or tire type. 

Taylor (2001) reviewed studies that document impacts of motor vehicle use on erosion, water 

resources, and riparian and aquatic habitats, including studies in Texas that found statistically significant 

effects from motor vehicle use on benthic macro invertebrates, water quality in pools, and disturbed 

versus non-disturbed riffles.

Chin and others (2004) conducted a study on the effects of ATVs on stream dynamics that evaluated 

the amount of pool filling by fine sediment (i.e., the reduction of pool volume and depth) as compared to 

control watersheds where ATV use was not occurring. They found that the watersheds impacted by ATV 

use showed a reduction of mean pool volume by as much as 50 percent. 

Impacts to stream channels, riparian areas, and water quality are possible where motorized use occurs 

in RCAs. The RCA widths in the SNFPA (USDA-FS 2004), which are used for the analysis of this 

project, were prescribed to protect both physical and biological components of the riparian system, 

including sediment and nutrient delivery, large woody debris recruitment, and habitat occupancy and use 
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Tahoe National Forest – 119

by various species. (Outside of RCAs, disturbances that result from motor vehicle use would be less 

likely to affect water and sediment reaching streams, meadows, or other hydrologically sensitive areas.) 

Comments: The short-term effects would be small and unquantifiable reductions in traffic-related 

sediment and related pollutants. Long-and short-term effects would essentially be the same for all action 

alternatives. The effects of the action alternatives would differ from the effects of the no-action alternative 

because the elimination of traffic from the unauthorized routes would reduce sediment detachment by 

motor vehicle use. The long-term effects would be smaller (less adverse) than short-term effects. Effects 

for the action alternatives would be smaller (less adverse) than the No Action Alternative, as measured by 

miles and area, because under the No Action Alternative, route proliferation and use of unauthorized 

routes would continue.

2&3) Direct/Indirect effects of additions to the NFTS and establishing motorized 

“Open Areas”

Considerations: Roads can directly affect physical channel dynamics when they encroach on floodplains 

or restrict channel migration. Roads can also affect meadows and wetlands directly by encroachment, and 

indirectly by altering surface and subsurface flow paths. Alteration of the hydrologic flow paths can 

indirectly affect meadow and wetland function, with the effects extending far beyond the area road itself. 

The effects can include erosion and/or lowering of the water table. Effects such as these would only be 

possible if routes are located within RCAs.

Stream crossings in particular have the potential to deliver increased runoff and sediment from the 

road, destabilize stream banks, and affect channel function. Schnackenberg and MacDonald (1998) found 

that fine sediment in stream channels in Colorado was more strongly correlated with the number of road 

crossings than with the Equivalent Clearcut Area (similar to the Equivalent Roaded Acres used in this 

analysis, but indexed to the effects of clearcuts rather than to roads) in the watershed. 

The potential for water to run down roads or trails is termed “diversion potential”. When this occurs, 

streamflow diversions can be a major cause of road-related erosion (Best and others 1995; Furniss and 

others 1997). 

Short-term timeframe: 1 year.

Long-term timeframe: The period used for long-term effects analysis is 20 to 30 years. This is a 

reasonable timeframe to think about and predict the expected vegetative recovery (and reduction in 

erosion) for areas disturbed by unauthorized use. 

Spatial boundary: The Forest Boundary.

Indicator(s): (1) miles of unauthorized routes added to NFTS in RCAs; (2) miles of ML 1 roads 

reopened in RCAs; (3) acres of motorized “Open Areas” in RCAs; (4) numbers of locations where routes 

divert or have potential to divert streamflow; (5) sum of route miles with documented erosional features.

Methodology: GIS analysis of routes and “Open Areas” in RCAs and stream crossings (assume all 

crossings have potential to divert streamflow). Compare no-action to action alternatives, and compare all 

alternatives to regulatory framework. Field road erosion inventories follow established protocol using

Green-Yellow-Red OHV monitoring.
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120 – Tahoe National Forest

Rationale: Published studies (see Reference section) have documented that streamflow diversions are 

a major cause of road-related erosion. Many published studies have documented that roads are a major 

disturbance in managed watersheds (Trombulak and Frissell 2000; Switalski and others 2004). Studies 

have consistently shown that roads produce more sediment than other forest management practices 

(Robichaud and others 2006). Unsurfaced roads and trails (such as the routes being analyzed for addition 

to the NFTS) contribute much more sediment than surfaced roads. For example, Coe’s study (2006) on 

the Eldorado National Forest found that native surface roads produced 10 to 25 times more sediment than 

rocked roads. Surface erosion was also dependent on soil type, road surface type, road grade, cross slope, 

age of the road, traffic volumes, and the effectiveness and spacing of drainage structures. In the South 

Fork Platte River, Welsh and others (2006) found that the mean sediment production from motor vehicle

trails was five times higher than the mean from unpaved road segments.

When roads concentrate surface flow and deliver it to streams via surface flow paths, they are termed 

“hydrologically connected”, and they functionally increase the drainage density (Wemple and others 

1996). Surface runoff can be delivered directly into streams via stream crossings or gullies formed at 

culvert outlets. In general, the greatest impacts from the transportation network come from the portions 

that are hydrologically connected. Roads and trails whose runoff drains onto hillsides where water 

infiltrates without reaching streams have fewer impacts on hydrology and water quality. In a study of 

forest road segments on the Eldorado National Forest, Coe (2006) found that 25 percent of the road 

segments surveyed was hydrologically connected. A study in the Kings River Experimental Watershed

(KREW) area in DNK analysis unit found that 13 percent of the road length in the study area was 

hydrologically connected (Korte and MacDonald 2005). Robichaud and others (2006) note that studies in 

the western US have found between 23 and 75 percent hydrologic connectivity of roads.

Roads concentrate overland flow and generate more runoff than undisturbed areas, and hydrologically 

connected roads deliver that runoff to streams more quickly and efficiently than undisturbed areas. 

Studies of the effects of roads on streamflows have had varied results, including that roads increased peak 

flows, decreased peak flows, and had no detectable effect (Gucinski and others 2001). Several studies 

(Bowling and Lettenmaier 1997, Ziegler and others 2007) have attributed the majority of the increases in 

streamflows on roads intercepting subsurface flow at cutbanks. Since very few of the unauthorized routes 

have cut and fill construction, interception of subsurface flow is likely to be less prevalent on these routes 

than on roads. However, the unauthorized routes still concentrate surface flow, and may be more likely to 

deliver it via hydrologically connected segments than authorized roads are due to the lack of maintenance 

they receive. Jones and Grant (1996) found that roads shifted the timing of peak flows to be slightly 

earlier, and also increased the peak flows slightly, though the increase was not statistically significant due 

to the variability of the events. There is more agreement that roads do not appear to affect annual water 

yield (Gucinski and others 2001).

4) Direct/Indirect effects of changes to the existing NFTS (this includes changing 

the vehicle class, season of use, and reopening Maintenance Level 1 roads)

Considerations: Changing the class of vehicle on already established routes would not increase the 

impacts to watershed resources. These are already existing routes; therefore there would be no additional 
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Tahoe National Forest – 121

ground disturbance. These routes would still have to meet standards and guidelines for resource 

protection.

Reopening ML 1 roads would have a small increase.

Traffic on native surface roads generally results in elevated sediment production, particularly if it 

occurs during the wet season. Road erosion rates increase with increased traffic, and if traffic is removed, 

the sediment concentration in road runoff decreases over time (Robichaud and others 2006). Ziegler and 

others (2001) found that motorcycle passes during rainfall simulation caused elevated sediment 

production; they also cite another study that found a more marked result from truck traffic. They attribute 

the increased sediment production to the amount of loose material on the road surface that is available for 

transport, because the spike in sediment transport gets smaller with each successive vehicle pass; 

however, they note that if the new routes had become incised by flowing water, the erosion would have 

been more persistent. 

For example, Forsyth and others (2006) found that high traffic levels on a gravel road during wet 

weather created ruts that increased erosion. Even in coarse-grained soils that do not develop rutting as a 

result of wet-weather use, more subtle surface deformation occurs that eventually renders the design 

shape of the road (crowning, drainage dips, etc) ineffective, and leads to increased road surface erosion.

Short-term timeframe: 1 year.

Long-term timeframe: The period used for long-term effects analysis is 20 years. This is a 

reasonable timeframe to think about and predict the expected vegetative recovery (and reduction in 

erosion) for areas disturbed by unauthorized use. 

Spatial boundary: The Forest Boundary.

Indicator(s): (1) miles of NFTS routes with proposed changes in vehicle class, season of use, and 

reopening of ML 1 roads in RCAs; (2) sum of route miles with documented erosional features; (3) 

numbers of locations where routes divert or have potential to divert streamflow (all stream crossings are 

assumed to have potential to divert streamflow).

Methodology: Field road erosion inventories follow established protocol using Green-Yellow-Red 

OHV monitoring. Compare no-action to action alternatives, and compare all alternatives to regulatory 

framework.

Rationale: Published studies (see Reference section) have documented that streamflow diversions are 

a major cause of road-related erosion.

5) Amendment to Forest Plan

The effects from the Forest Plan Amendment are covered under the changes to seasonal restriction in 

element 4.

6) Cumulative Effects

Considerations: The cumulative effects to erosion/sediment risks were analyzed using the EMDS erosion 

risk values averaged at the HUC6 scale (See the Soil Resources Section and Appendices F, Watershed 

Analysis and L , Soils Analysis). This cumulative effects analysis compares the HUC6 route related 
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122 – Tahoe National Forest

erosion risk and the native surface, motorized route density to assess the effects of proposed changes in 

route density related to sub-basin erosion risk.

The Equivalent Road Acre (ERA) model was developed as a way to evaluate the accumulation of 

impacts from different activities through time. There are limitations to the ERA model, including: ERAs 

are only an indicator, and cannot be used to estimate quantitative changes in stream channel conditions; 

the higher risk associated with near-stream disturbance (as opposed to disturbance far from any stream 

channel) is not factored into the analysis; and the method does not account for site-specific BMPs (i.e., all 

roads are weighted the same, regardless of their management and condition). Changes to the existing

NFTS are minor and not expected to have a perceptible contribution to cumulative effects. The detailed 

assessment found in Appendix A (Site Specific Road, Trail and Open Area Information) details for more 

specific information of the area, including the position of the disturbances relative to the drainage network

and whether mitigations are in place to be factored into the final determination of the risk for CWEs.

Short-term timeframe: not applicable; cumulative effects analysis will be done only for the longterm time frame.

Long-term timeframe: The period used for long-term effects analysis is 30 years. This is a 

reasonable timeframe to think about and predict the expected vegetative recovery (and reduction in 

erosion) for areas disturbed by unauthorized use. 

Spatial boundary In the DEIS analysis, this information was compiled at the HUC7 scale.

Comments received on the DEIS said that this analysis was too complex and confusing. Upon further 

review of the data, the decision was made to use HUC6 watersheds for the SDEIS analysis. This 

decreases the number of watersheds by around 80 percent, does not change the results of the analysis, and 

makes the analysis more understandable. This scale is large enough to encompass the effects of 

management activities, but not so large as to mask the effects of the proposed actions. In the SDEIS the

CWE results are reported at the sub-basin, basin, and Forest scale.

Because HUC6 watersheds range from 10,000 to 40,000 acres in size, density (e.g., miles of road & 

trails/acre of HUC6 or number of crossings/acre of HUC6) is a more meaningful measurement of route 

risks than simply number of miles. Therefore, road/trail density is used in this analysis as well as the

miles of roads and trails and the number of crossings. For a more site specific scale, see Appendix A, Site 

Specific Road, Trail and Open Area Information, for trail-specific erosion mitigation measures.

Indicator(s): Equivalent Roaded Areas in acres.

Methodology: Standard ERA model per Regional policy, focusing on road and trail related ERAs and 

assuming unauthorized routes without traffic would passively recover within the timeframe. The method 

allows a quantitative assessment of past, present, and reasonably foreseeable effects for all USFS land-use 

activities, and the differences between alternatives can be compared to the existing route related ERAs.

Rationale: See considerations discussed under methodology.

Comments: See the Soils Methodology section for assumption regarding passive recovery of 

unauthorized routes that are not brought into the NFTS.
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Tahoe National Forest – 123

Affected Environment: Hydrology

Existing Water Supply

The TNF contains portions of headwaters of the American, Bear, Feather, Truckee and Yuba Rivers. The 

American, Bear and Yuba Rivers flow westward from the crest of the Sierra Nevada to the Sacramento 

River in the City of Sacramento. The headwaters of the Middle Fork Feather River are in the Sierra Valley

area. The river is formed by the confluence of several streams draining the surrounding mountains and 

then flows west to join the Sacramento River near Marysville. The American, Bear, Feather, and Yuba 

rivers and their tributaries provide water for domestic, agricultural, environmental and industrial uses as 

well as power production. The Truckee River Basin covers an area from Lake Tahoe in California to 

Pyramid Lake, located approximately 50 air miles away in Nevada. Approximately 760 square miles 

(almost 25 percent of the basin), lie within California. Most of the precipitation and water storage occur 

within the California part of the Truckee River Basin. The Truckee River, from south of Bear Creek 

confluence to the area near the California border near Floriston, is within the TNF boundary. The Truckee 

River provides the majority of the municipal water supply for the Reno-Sparks area.

The Wild and Scenic status of rivers on the TNF can be found in Section 3.09, Inventoried Roadless 

Areas and Special Areas.

Most of the watersheds on the Tahoe are highly regulated systems. The American, Yuba, and Bear 

River systems are due to complete FERC re-licensing by 2013. Truckee River operates under the Truckee 

River Operating Agreement. The Sierra Valley is an adjudicated basin. This project is not likely to impact 

existing water supply to any measurable extent.

Existing Water Quality

Compared to other parts of California and the United States, the Sierra Nevada overall has relatively low 

sediment yields (Kattelmann, 1996). General estimates show that the Sierra Nevada has the lowest 

sediment yield in California (generally less than 100 m3/km2/year). Sediment transport measurements in a 

variety of streams in the eastern Sierra Nevada were generally less than 10 m3/km2/year. A Soil 

Conservation Service report classified sediment yield below 150 m3/km2/year as “low” with respect to 

nationwide rates (Kattelmann, 1996). Table 3.02-12 shows some annual sediment yield data for 

watersheds on the Tahoe National Forest. These figures show that the Truckee River system has lower 

sediment yields than the rivers on the west side of the Forest. The American, Yuba and Feather River 

systems appear to have similar sediment yields.
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124 – Tahoe National Forest

Table 3.02-12. Sediment yields from reservoir surveys, suspended sediment records, and other estimates 

(Kattelmann, 1996)

Watershed Annual Sediment 

Yield (m3/km2)

American – Ralston 80

American – Auburn Dam Site 130

American – Folsom 250

Bear – Combie 360

Feather – Oroville 90

100

120

Truckee – Upper Truckee

Squaw Creek

Trout Creek

21

12, 93

12

Yuba – Nonmining

Mining

North Yuba – Bullards Bar

160

3,300

130

Water Quality Management

According to the California Water Plan Update (CA DWR 1998) the TNF is encompassed by three major 

hydrologic regions. One region is on the Westside of the Sierra Nevada crest (the Sacramento River); the 

North and South Lahontan regions are on the eastern side. The Central Valley Regional Water Quality 

Control Board oversees and sets the standards for the Feather, Yuba, Bear and American River systems. 

The Lahontan Regional Water Quality Control Board oversees and sets the standards for the Truckee 

River. The Forest Service has a memorandum of understanding with the State that names the Forest 

Service as a “Designated Management Agency” that will prescribe and implement a water quality control 

program to protect the waters of the state to meet state and federal regulations as well as the standards set 

in the Central Valley Water Quality Control Board Basin Plan as amended for commercial silvicultural 

practices by Resolution R5-2006-0026 (2006).

The TNF generally produces surface water of excellent quality, suitable for almost any use. 

Contaminant levels in most waters are lower than amounts specified in the States of California and 

Nevada stream quality standards (Kattelmann 1996). Most runoff would be suitable as drinking water 

except for the risk of bacteria and pathogens, such as Giardia lamblia, Campylobacter ssp., and 

Cryptosporidium ssp. In the backcountry, inadequate disposal of human waste and pathogens carried by 

mammals have caused sufficient contamination to make drinking untreated water risky. Low-level release 

of nutrients from human activities along wilderness lakes may have stimulated increased plant growth on 

some lake bottoms (Kattelmann 1996) reducing clarity and causing shifts in aquatic communities as well 

as reducing the aesthetics of natural lake conditions. Generally, very little water from National Forests in 

the Sierra Nevada region is heavily polluted or contaminated by chemicals, bacteria, or parasites at 

concentrations above background levels (Kattelmann 1996). Most waters satisfy the fishable and 

swimmable objectives of the Clean Water Act (1987).
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

Tahoe National Forest – 125

Water quality in forested areas can be impacted by many activities. Most pollutants come from nonpoint sources, i.e. from diffuse sources not concentrated into pipes, drains, flumes, or ditches (Clean 

Water Act, 1987). Examples include erosion from roads and parking areas. Sediment at levels above 

natural rates of erosion is the most common non-point source pollutant in forested ecosystems. Roads can 

pollute groundwater as well as surface water. Forest roads potentially add more sediment to streams than 

any other forest operation. Research has shown that 90 percent of the sediment that ends up in our 

nation’s waters from forested lands is associated with improperly designed and maintained roads. Water 

quality in lakes, streams, springs, and wetlands can be protected by proper road location and construction 

and adequate maintenance. A few rural communities and abandoned mining sites within national forests 

constitute point sources of pollution.

There are six water bodies on the TNF that are listed as impaired on the EPA’s 303(d) List. These are 

the Truckee River (sediment); Stampede Lake (pesticides of unknown origin), Donner Lake (PCBs), 

Kanaka Creek (arsenic), Squaw Creek (sedimentation/siltation) and Humbug Creek (lead, sediment, etc.). 

Table 3.02-13 displays the 303(d) listed water bodies and the reason for listing.

Table 3.02-13. Impaired Water Bodies on the TNF Listed on the EPA 303(d) List

Water Body Name Pollutant/Stressor Source Area Affected

Humbug Creek Copper, Mercury, Zinc, 

Sedimentation/Siltation

Resource extraction abandoned mines 9 miles

Kanaka Creek Arsenic Resource extraction abandoned mines 1 mile

Donner Lake Priority Organics Source Unknown 960 acres

Stampede Reservoir 

(recommended for delisting)

Pesticide (lindane) Source Unknown 3,444 acres

Squaw Creek Sedimentation/Siltation Construction/Land development, Other 

Urban Runoff, Hydro modification, 

Drainage/Filling of Wetlands, Highway 

Maintenance And Runoff, Natural 

Sources, Recreational Activities, 

Nonpoint Source

8 miles

Truckee River Sedimentation/Siltation Source Unknown 106 miles

The Truckee River, Squaw Creek, and Humbug Creek (Middle Yuba River) are currently listed on the 

Impaired Water body list (303(d)) for sediment. The Lahontan Regional Water Quality Control Board 

recently developed a Total Maximum Daily Load (TMDL) for sediment. Effects of this project on these 

watersheds are discussed under Environmental Consequences in the cumulative effects section.

Existing Routes in Riparian Conservation Areas

The most serious impacts of roads and motorized trails occur where they are in close proximity to streams 

or wetlands (see Appendix A [Site Specific Road, Trail and Open Area Information] and Appendix I 

[Riparian Conservation Objectives]). Native surface roads and motorized trails within RCAs have the 

potential to impact water resources including water quality. Table 3.02-14 shows the miles and density of 

native surface roads and motorized trails by major river basin. There are currently 1054.1 miles of native 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

126 – Tahoe National Forest

surface roads and motorized trails within RCAs. So current density of native surface roads and motorized 

trails in RCAs on the TNF is 2.6 miles per square mile. The highest number of miles in RCAs is found in 

the Yuba River Basin and the lowest number of miles in RCAs is in the Feather Basin. The highest 

density of native surface roads and motorized trails is found in the Truckee and Feather River basins and 

the lowest in the American River and Bear River basins.

Table 3.02-14. Miles and density of native surface roads and motorized trails in RCAs by major river basin

and the number and density of native surface road and motorized trail perennial and intermittent stream 

crossings by major river basin

River Basin Miles of Native Surface Roads 

and Motorized Trails in RCAs 

(Density mi/sq mi)

Number of Native Surface Road 

and Motorized Trail Stream 

Crossings (Density # crossings/ sq 

mi RCA)

Middle Truckee River 170.2 (5.1) 213 (6.3)

Little Truckee River 136.1 (2.9) 281 (4.6)

Subtotal Truckee 306.4 (3.8) 494 (6.1)

Feather 114.9 (3.8) 358 (12.0)

North Yuba 207.8 (2.4) 485 (5.6)

Middle Yuba 85.9 (2.4) 288 (7.2)

South Yuba 140.0 (2.2) 322 (5.1)

Subtotal Yuba 433.7 (2.3) 1095 (5.8)

Bear 16.6 (1.6) 59 (8.1)

Middle Fork American 83.9 (1.6) 157 (3.3)

North Fork American 79.4 (1.7) 239 (4.6)

Subtotal American 163.3 (1.6) 396 (4.0)

Tahoe National Forest 1054.1 (2.6) 2408 (5.9)

Existing Native Surface Road and Motorized Trail Stream Crossings

Stream crossings have direct effects on the channel and local sediment regime. The basic problem comes 

down to disturbing the stream bed, banks, floodplain, and terraces of the stream. Streamflow diversions at 

road and motorized trail-stream crossings can result in significant erosion of road surfaces and hillslopes 

(for example, Best, 1995). Because the crossing is coincident with the channel, there is little opportunity 

to buffer any impacts of the crossing. Also, ditches near the crossing drain directly into the stream, often 

contributing sediment to the stream. Although any stream crossing can have some impact on the channel, 

careful engineering, construction, and maintenance can limit the severity of the impacts. 

All road-stream crossings were assumed to have the potential to divert streamflow. Table 3.02-14

shows the number and density of native surface roads and motorized trail stream crossings by major river 

basin. Currently there are 2,408 native surface road and motorized trail perennial and intermittent stream 

crossings on the TNF. Crossing density on the TNF is 5.9 crossings per square mile. Crossing density is 

highest in the Feather River basin and lowest in the American River basin.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

Tahoe National Forest – 127

Documented Erosional Features

Field surveys were completed for approximately 100 miles of authorized and unauthorized motorized 

routes. See the Soil Resources section for full discussion of field surveys. See Appendix A (Site Specific 

Road, Trail and Open Area Information) for route specific erosion impacts. Projecting the percent erosion 

found during field surveys, an estimated 250 miles of routes could have erosional features.

Existing Landscape Erosion/Sedimentation Risk

Many factors can influence the risk of erosion and potential impacts to watershed resources including: 

soil erosion/sedimentation potential; stream density; and the type and density of roads on the landscape. 

The presence of highly erosive soils/landscapes or a high density of native-surfaced, motorized routes 

does not mean that there would be negative effects to soil resources. But the presence of both high erosion 

risk and a high density of motorized routes indicate that there could be a higher risk of accelerated erosion 

and sediment production due to motorized roads and trails. 

The inherent risk of erosion of the soils and subsequent sediment movement within the TNF was 

assessed using two methods: the R-5 soil erosion hazard rating found in TNF Soil Resource Inventory and 

the Ecosystem Management Decision Support Model (EMDS). The R-5 EHR ratings indicate that 82 

percent of the soils on the TNF have a high to very high erosion risk (Table 3.02-8). The EMDS model 

was used to refine the potential soil erosion risk analysis (See the Soil Resources section and Appendix 

L). The EMDS erosion risk scores were averaged by HUC6 watershed to assess the motorized route 

related erosion risk at the landscape scale. This scale is large enough to encompass the effects of 

management activities, but not so large as to mask the effects of the proposed actions. The EMDS 

landscape erosion risk score were divided into quartiles to compare the relative erosion potential of 

individual watersheds. The Truckee River landscape erosion scores were the only average score in the 

bottom 25 percent, therefore the Truckee River Basin has the lowest potential erosion risks on the TNF.

Whereas the North Yuba River, which is much steeper, has more geodebris slides, and more erosive soils, 

has the highest potential erosion risks on the TNF, see Figure 3.02-2 and Table 3.02-15.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

128 – Tahoe National Forest

Figure 3.02-2. EMDS Landscape erosion values by HUC6.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

Tahoe National Forest – 129

Table 3.02-15. EMDS Erosion Risk rating and density of native surface roads and motorized trails by major 

river basin

River Basin EMDS Potential Erosion Risk

Class

Density of Native Surface Roads 

and Motorized Trails

(miles/sq. mi.)

Middle Truckee River 0.58 (0-25%) 4.4

Little Truckee River 0.65 (0-25%) 2.9

Subtotal Truckee 0.61 (0-25%) 3.7

Feather 0.62 (0-25%) 2.6

North Yuba 0.40 (75-100%) 2.5

Middle Yuba 0.44 (50-75%) 2.8

South Yuba 0.48 (25-50%) 2.7

Subtotal Yuba 0.44 (50-75%) 2.7

Bear 0.44 (50-75%) 3.7

Middle Fork American 0.45 (50-75%) 2.5

North Fork American 0.42 (50-75%) 2.0

Subtotal American 0.43 (50-75%) 2.2

Tahoe National Forest 0.48 (25-50%) 2.8

This analysis focuses native surface (dirt) roads and motorized trails. Not incorporated in the focused 

analysis were surfaced roads, non-motorized trails, over-snow routes, and county and state roads because 

these routes tend to have a lower erosion potential. Because HUC6 watersheds range from 10,000 to 

40,000 acres in size, density (e.g., miles of road & trails/acre of HUC6 or number of crossings/acre of 

HUC6) is a more meaningful measurement of route risks than simply the number of miles. Therefore, 

road/trail density is used in this analysis as well as the miles of roads and trails and the number of 

crossings. For a more site specific scale, see Appendix A, Site Specific Road, Trail and Open Area 

Information, for trail-specific erosion mitigation measures.

The existing native surface road and motorized trail density of HUC6 watersheds was divided into the 

following density classes based on quartiles (25 percent of watershed in each density class): 0.8 to 2.3

mi/sq.mi., 2.3 to 2.8 mi/sq.mi., 2.8 to 3.5 mi/sq.mi., and 3.5 to 6.5 mi/sq.mi. For example, the Middle 

Truckee River basin currently has a density of 4.4 mi/sq mi, which is in the highest density class found on 

the TNF. This analysis was done so that proposed changes in route density could be compared to the 

existing condition.

Table 3.02-15 shows the average EMDS Erosion Risk rating and the existing native surface road and 

motorized trail density by major river basin. The potential erosion risks in the Truckee and Feather River 

basins are the lowest on the TNF. The Truckee River and the Bear River basins have existing density of 

native surface road and motorized trails of 3.7 miles per square mile (the highest on the TNF). Erosion 

risk in the Middle Truckee River basin is in the lowest erosion risk class (The basins with erosion risk 

values in the 0-25 percent of the scores on the TNF). The Bear River basin is in the higher potential 

EMDS Erosion Risk quartile (50-75% Class). The potential erosion risk is higher in the Bear River basin 

than in the Truckee River basin; therefore more erosion related impacts due to motor vehicle use would be 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

130 – Tahoe National Forest

expected in the Bear River than the Truckee River. The Yuba River and American River basins have 

similar erosion risks (higher EMDS Erosion Risk class), with the South Yuba having a slightly lower 

EMDS Erosion Risk than the rest of the Yuba River basin. The existing density of native surface roads 

and motorized trails in the Yuba River basin averages 2.7 miles/ square mile. The Middle Yuba has the 

highest density (2.8 mi/sq mi) and the North Yuba has the lowest (2.5 mi/sq mi). The American River 

basin is in the higher EMDS Erosion Risk quartile. Native surface road and motorized trail density 

averages 2.2 mi/sq mi. The Middle Fork American River basin has a density of 2.5 mi/sq mi and the 

North Fork American River basin has a density of 2.0 mi/sq mi.

Existing Equivalent Road Acres

The cumulative effects of this project on watershed resources (CWE) are analyzed at several scales 

(Forest, HUC6 Watershed, and RCA (See Riparian Conservation Objectives in Appendix I). The Forestwide CWE analysis run for a recent Forest-wide fire planning exercise and project specific NEPA 

documents were used to identify HUC 7 watersheds that are at or over Threshold of Concern (TOC).

Table 3.02-16 displays the number of watersheds and acres that are currently over the Threshold of

Concern.

Table 3.02-16. Watersheds and acres that are currently over the Threshold of Concern

Threshold of Concern Number of Watersheds Acres

Over 100% Threshold of Concern 3 10,600

Under 100% Threshold of Concern 221 809,800

There are three HUC7 watersheds identified as being over TOC. These watersheds are Trout Creek,

Alder Creek, and Upper Cold Stream. The majority of the ERA disturbance in the Trout Creek and Alder 

Creek watersheds is due to the Tahoe Donner Subdivision on private land. Upper Cold Stream has 

proposed projects that would take the watershed to TOC.

Environmental Consequences: Hydrology

Cross country motorized vehicle travel increases the amount of native surface routes on the TNF. The 

motorized trails being considered for addition to the NFTS are native surface wheel tracks that currently 

exist on the ground, so the hydrologic footprint of the routes already exists. The primary change 

considered in this analysis are the prohibition of cross country travel, changes in miles of motorized use 

on existing native surface roads and motorized trails and changes in class of vehicle or season of use on 

the existing NFTS. Therefore, the effects of route designation on soil and watershed resources focus on 

native surface roads and motorized trails within the FS boundary. These are the roads and motorized trails

where effects on soil and watershed resources are most likely to occur. Surfaced roads are not included

because generally mechanical soil loss by erosion and subsequent sediment production is very low on 

them.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

Tahoe National Forest – 131

Permitting motor vehicle use only on designated routes would reduce the extent of impacts off of the 

NFTS. While impacts on designated routes may be more severe than those that occur from more 

dispersed use, they can be effectively managed and mitigated. Restricting cross country travel would 

minimize the number of stream crossings and riparian impacts, and limit them to known areas that can be 

monitored and maintained.

Direct and Indirect Effects to Watershed Resources

Direct impacts to watersheds and stream courses that result from this project are limited. There are no 

new ground disturbing activities proposed with this project. The routes being evaluated in this analysis 

already exist on the ground, but may require upgrading to NFTS standards as well as periodic 

maintenance. They are compacted and generally lack vegetation. Runoff from the surface is collected and 

discharged as potentially erosive flows at points below the road or motorized trail. Some are eroded or 

causing erosion, others are stable and are not causing any negative resource impacts. From the standpoint 

of watershed resources, most adverse impacts associated with these roads and motorized trails have

already occurred. Therefore, on these routes the potential effects on watershed resources are related to 

sustaining road or trail function and protecting water quality. It should be noted that most roads and 

motorized trails on the TNF have some site specific risk to water resources. Many of these risks can be 

mitigated.

Road and trail closures may result in less erosion to the extent that recurrent disturbance of the soil 

surface by OHV traffic is the primary cause of erosion. In many situations, however, erosion and 

subsequent sediment delivery to water bodies is the result of a combination of factors that include

motorized use, as well as, season of use, a lack of drainage, inadequate maintenance, and poor trail design 

or location. If non-motorized trail users continue to use the routes some erosion and sediment transport 

could continue to occur.

The primary concern or effect of this project on the watershed resource is the potential for soil erosion 

and subsequent effects of sediment transport and deposition. Subsequent sediment deposition can damage 

terrestrial plants and aquatic organisms. High levels of sediment deposition can also reduce the utility of 

facilities for water storage and diversion and hydroelectric production. Activities in and near stream 

channels have the greatest potential for altering sediment delivery and storage as well as channel form.

Because this document covers existing wheel tracks, the impacts to hydrologic function and buffering 

capacity have already taken place.

The erosion that may occur on the trail or road surface is a concern regarding loss or degradation of 

the facility. Erosion and sediment generated by the trail or road surface may be a concern to water quality 

if there is the potential for its delivery to a drainage feature. 

All alternatives would have direct and indirect effects on watershed resources that vary by alternative.

Route designation would affect soil erosion and subsequent sediment delivery to streams to the extent that 

activities resulting from designation or prohibition of use (1) affect the amount of traffic on routes; (2) 

affect the season of use (3) add motorized trails to the NFTS with highly erosive soils; (3) affect types of 

maintenance; and (4) affect the potential for recovery and restoration.
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Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

132 – Tahoe National Forest

Route Recovery: See Soils section above

Projected Effects on Watershed Resources on the TNF

Projected Water Supply (direct, indirect, cumulative)

None of the action alternatives would increase impacts to water supplies, because this project only 

designates the class of vehicles and season of use on existing routes and does not propose to construct any 

new routes.

Projected Water Quality

There are six water bodies on the TNF that are listed as impaired on the EPA’s 303(d) List. Table 3.02-17

displays the 303(d) listed water bodies, the reason for listing and any potential impacts which may 

contribute to the reasons for their listing.

Humbug Creek is listed as a 303(d) Impaired Water Body by EPA due to copper, mercury, zinc, 

sedimentation and siltation. While the source of the copper, mercury and zinc contamination is unknown, 

it is generally felt to be generated by abandoned mines. There is no change under any of the alternatives 

to the number of abandoned mines potentially contributing to this contamination.

The water body is also listed for sedimentation and siltation. Native surface roads and trails and their 

season of use can contribute to sedimentation and siltation. Virtually all of the native surface roads in this 

watershed are privately owned. None of the alternatives change the amount of private roads or their 

season of use. The Forest Service has jurisdiction of less than one mile of unauthorized routes in this 

watershed. All of the action alternatives except Alternative 5 prohibit use of this route by motorized

vehicles. In Alternative 5 this motorized trail is added to the NFTS, however seasonal restrictions prohibit 

use of this motorized trail during the wet time of the year thereby reducing the potential for sedimentation 

and siltation.

Cross country travel by motorized vehicles can also have an impact of sedimentation and siltation. 

Cross country travel is prohibited in all of the action alternatives.

Kanaka Creek is listed as a 303(d) Impaired Water Body by EPA due to arsenic. While the source of 

the arsenic contamination is unknown, it is generally felt to be due the number of abandoned mines in the 

area and the type of rock formations. None of the alternatives change the number of abandoned mines nor 

alter the rock formations.

Donner Lake is listed as a 303(d) Impaired Water Body by EPA due to priority organics (PCB). 

While the source of the priority organics contamination is unknown, it is generally felt to be due to 

historic activity associated with the transportation utility corridor running through the watershed. None of 

the alternatives change the activities associated with the transportation utility corridor.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

Tahoe National Forest – 133

Table 3.02-17. 303(d) listed water bodies, the reason for listing and potential impacts

Impaired 

Water Body

Pollutant/Stressor Indicator of Potential Impact Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Humbug 

Creek

Copper, Mercury, 

Zinc, 

Sedimentation & 

Siltation

National Forest System Native Surface 

Roads and Trails Open Year Round (Miles)

<1 0 0 0 0 0 0

National Forest System Native Surface 

Roads and Trails Open Seasonally (Miles)

0 0 0 0 <1 0 0

Private Ownership Native Surface Roads 

and Trails Open Year Round (Miles)

4 4 4 4 4 4 4

Cross Country Travel Continues Prohibited Prohibited Prohibited Prohibited Prohibited Prohibited

Abandoned Mines No Change No Change No Change No Change No Change No Change No Change

Kanaka 

Creek

Arsenic Mining, Rock Formations No Change No Change No Change No Change No Change No Change No Change

Donner 

Lake

Priority Organics Transportation Utility Corridor Activity No Change No Change No Change No Change No Change No Change No Change

Stampede 

Reservoir

Pesticide (lindane) Pesticide Applications No Change No Change No Change No Change No Change No Change No Change

Squaw 

Creek

Sediment & 

Siltation

National Forest System Native Surface 

Roads and Trails Open Year Round (Miles)

<1 0 0 0 0 0 0

National Forest System Native Surface 

Roads and Trails Open Seasonally (Miles)

0 0 0 0 <1 0 0

Private Ownership Native Surface Roads 

and Trails Open Year Round (Miles)

40 40 40 40 40 40 40

Cross Country Travel Continues Prohibited Prohibited Prohibited Prohibited Prohibited Prohibited

Truckee 

River

Sediment & 

Siltation

National Forest System Native Surface 

Roads and Trails Open Year Round (Miles)

0 0 0 0 0 0 0

National Forest System Native Surface 

Roads and Trails Open Seasonally (Miles)

685 494 434 0 0 0 451

Private Ownership Native Surface Roads 

and Trails Open Year Round (Miles)

628 628 628 628 628 628 628

OHV Open Areas (Number) 4 4 1 1 4 4 4

Cross Country Travel Continues Prohibited Prohibited Prohibited Prohibited Prohibited Prohibited
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

134 – Tahoe National Forest

Stampede Reservoir is listed as a 303(d) Impaired Water Body by EPA due to pesticides (lindane). 

While the source of the pesticide contamination is unknown, it is generally felt to be due historic pesticide 

applications in the area. None of the alternatives change the activities associated with pesticide 

applications in the area.

Squaw Creek is listed as a 303(d) Impaired Water Body by EPA due to sedimentation and siltation.

Native surface roads and trails and their season of use can contribute to sedimentation and siltation. 

Virtually all of the native surface roads in this watershed are privately owned. None of the alternatives 

change the amount of private roads or their season of use. The Forest Service has jurisdiction of less than 

one mile of unauthorized routes in this watershed. All of the action alternatives except Alternative 5 

prohibit use of this trail by motorized vehicles. In Alternative 5 this unauthorized route is added to the 

NFTS, however seasonal restrictions prohibit use of this route during the wet time of the year thereby 

reducing the potential for sedimentation and siltation.

Cross country travel by motorized vehicles can also have an impact of sedimentation and siltation. 

Cross country travel is prohibited in all of the action alternatives.

The Truckee River is listed as a 303(d) Impaired Water Body by EPA due to sedimentation and 

siltation.

Native surface roads and trails and their season of use can contribute to sedimentation and siltation. 

Approximately half (628 miles) of the native surface roads in this watershed are privately owned. None of 

the alternatives change the amount of private roads or their season of use. The Forest Service has 

jurisdiction of 685 miles of native surface roads and motorized trails within this watershed. All of the 

action alternatives reduce the number of native surface roads and motorized trails available for use by 

motorized vehicles by approximately 100 miles (15%). In addition all action alternatives include seasonal 

restrictions which prohibit use of these roads during the wet time of the year thereby reducing the 

potential for sedimentation and siltation.

There are also 4 OHV “Open Areas” within this watershed. The Prosser Pits OHV Open Area is 

already established as an “Open Area.” Any sedimentation being generated by this area would continue 

under all alternatives. Boca, Prosser and Stampede Reservoirs are currently managed to allow access to 

the shoreline below the high water line by motor vehicles when the soils are dry. Speeds are generally 

slow and since this access is allowed on dry soils only, any additional sediment generated by vehicles 

accessing the shoreline is minimal. Some fugitive dust could be created by the vehicles on the dry soils 

and possible drift into the reservoir, but the amount is also felt to be minimal. These reservoirs are 

established as “Open Areas” for shoreline access by motorized vehicles in Alternative 2 for a total of 

2,589. In Alternative 6, 244 acres of the most stable, highly used areas are proposed as “Open Areas.” In 

Alternative 6 the class of vehicles allowed in these “Open Areas” is restricted to highway legal vehicles 

only which further mitigate the potential for sedimentation. The use of these dry lake beds by motorized 

vehicles is prohibited in Alternatives 3, 4, 5, and 7. Use is not prohibited at these reservoirs in Alternative 

1.

Cross country travel by motorized vehicles can also have an impact of sedimentation and siltation. 

Cross country travel is prohibited in all of the action alternatives.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

Tahoe National Forest – 135

Stream crossings and native surface roads and motorized trails within close proximity to streams are 

the areas of highest potential sediment delivery to the stream channel. Figure 3.02-3 shows the density of 

native surface road and motorized trail perennial and intermittent stream crossings by alternative. Figure 

3.02-4 shows the native surface road and motorized trail density in RCAs by alternative. All action 

alternatives would decrease the density of native surface roads and motorized trails within RCAs and 

native surface road and motorized trail stream crossings.

Figure 3.02-3. Native surface road and motorized trail crossing density in the Truckee River Basin (within the 

TNF boundary) by Alternative

Motorized, Native Surface Crossing Density in the Truckee 

River Basin

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1 2 3 4 5 6 7

Alternatives

Percent HUC7s in Truckee River 

Basin

Highest

Mod High

Mod Low

Lowest
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

136 – Tahoe National Forest

Figure 3.02-4. Native surface road and motorized trail density in RCAs in the Truckee River Basin (within the 

TNF boundary) by Alternative

Proposed Routes in Riparian Conservation Areas

Table 3.02-18 shows the miles and density of native surface roads and motorized trails in RCAs by 

major river basin and alternative. These figures include 394.6 miles of private roads within RCAs on 

private land. Action alternatives would decrease the number of existing crossings by 20 to 31 percent. The 

largest decrease is Alternative 3 and the smallest is Alternative 5.

Motorized, Native Surface RCA Route Density in the 

Truckee River

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1 2 3 4 5 6 7

Alternative

Percent of HUC7s in Truckee 

River Basin by RCA Density 

Quantile

Highest

Mod High

Mod Low

Lowest
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

Tahoe National Forest – 137

Table 3.02-18. Miles and density of native surface roads and motorized trails in RCAs by alternative (Density 

mi per square mile of RCA)

River Basin Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Middle Truckee River 170.2

(5.1)

144.3

(4.3)

141.3

(4.2)

141.3

(4.2)

144.4

(4.3)

143.9

(4.3)

141.3

(4.2)

Little Truckee River 136.1

(2.9)

95.1

(2.0)

83.2

(1.8)

85.5

(1.8)

97.1

(2.0)

82.4

(1.7)

85.9

(1.8)

Subtotal Truckee River 306.4

(3.8)

239.4

(3.0)

224.5

(2.8)

226.8

(2.8)

241.6

(3.0)

236.3

(2.9)

227.2

(2.8)

Feather River 114.9

(3.8)

78.9

(2.6)

62.5

(2.1)

62.5

(2.1)

78.9

(2.6)

70.7

(2.4)

62.5

(2.1)

North Yuba River 207.8

(2.4)

155.3

(1.8)

126.9

(1.5)

127.1

(1.5)

169.4

(1.9)

135.8

(1.6)

127.4

(1.5)

Middle Yuba River 85.9

(2.4)

64.8

(1.6)

59.3

(1.5)

59.8

(1.5)

65.0

(1.6)

62.6

(1.6)

59.3

(1.5)

South Yuba River 140.0

(2.2)

123.5

(1.9)

107.8

(1.7)

110.7

(1.8)

123.6

(2.0)

114.6

(1.8)

111.0

(1.8)

Subtotal Yuba River 433.7

(2.3)

343.6

(1.8)

294.0

(1.5)

297.6

(1.6)

358.0

(1.9)

313.0

(1.6)

297.8

(1.6)

Bear River 16.6

(2.3)

13.7

(1.8)

10.8

(1.5)

11.6

(1.6)

14.0

(1.9)

11.7

(1.6)

11.6

(1.6)

North Fork American River 83.9

(1.6)

68.8

(1.4)

63.4

(1.3)

63.6

(1.3)

69.6

(1.5)

66.3

(1.4)

63.6

(1.3)

Middle Fork American River 79.4

(1.7)

66.2

(1.3)

53.1

(1.0)

53.1

(1.0)

67.2

(1.3)

55.7

(1.1)

53.8

(1.0)

Subtotal American River 163.3

(1.6)

135.0

(1.4)

116.4

(1.2)

116.7

(1.2)

136.9

(1.4)

121.9

(1.2)

117.4

(1.2)

TNF Total 1054.1

(2.6)

828.7

(2.0)

726.2

(1.8)

733.3

(1.8)

847.4

(2.1)

771.8

(1.9)

734.6

(1.8)

Percent Reduction by Alternative 21% 31% 30% 20% 27% 30%

Proposed Native Surface Road and Motorized Trail Stream Crossings

There are currently 2,408 native surface road and motorized trail perennial and intermittent stream

crossings on the TNF (Table 3.02-19). Crossing density is 5.9 crossings per square mile averaged over the 

TNF. This includes 714 stream crossings on private land. All of the Action alternatives would decrease the 

number of crossings by 21 to 35 percent. The largest decrease is Alternative 3 and the smallest is 

Alternative 5.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

138 – Tahoe National Forest

Table 3.02-19. Number and density of native surface road and motorized trail stream crossings by alternative

(Density, number of crossings per square mile of RCA)

River Basin Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Middle Truckee River 213 (6.3) 186 (5.5) 183 (5.4) 183 (5.4) 187 (5.6) 189 (5.6) 183 (5.4)

Little Truckee River 281 (5.1) 217 (4.6) 183 (3.9) 187 (3.9) 218 (4.6) 205 (4.3) 189 (4.0)

Subtotal Truckee 

River 494 (6.1) 403 (5.0) 366 (4.5) 370 (4.6) 405 (5.0) 394 (4.9) 372 (4.6)

Feather River 358 (12.0) 236 (7.9) 192 (6.4) 192 (6.4) 236 (7.9) 218 (7.3) 192 (6.4)

North Yuba River 485 (5.6) 351 (4.0) 256 (2.9) 259 (3.0) 396 (4.6) 280 (3.2) 259 (3.0)

Middle Yuba River 288 (7.2) 226 (5.7) 208 (5.2) 209 (5.3) 226 (5.7) 221 (5.6) 208 (5.2)

South Yuba River 322 (5.1) 262 (4.2) 223 (3.5) 229 (3.6) 262 (4.2) 237 (3.8) 228 (3.6)

Subtotal Yuba 1095 (5.8) 839 (4.4) 687 (3.6) 696 (3.7) 884 (4.7) 738 (3.9) 695 (3.7)

Bear River 59 (8.1) 47 (6.4) 38 (5.2) 41 (5.6) 47 (6.4) 41 (5.6) 41 (5.6)

North Fork American 

River

157 (3.3) 127 (2.6) 117 (2.4) 118 (2.5) 127 (2.7) 125 (2.6) 118 (2.5)

Middle Fork American 

River

239 (4.6) 195 (3.8) 154 (3.0) 156 (3.0) 199 (3.8) 159 (3.1) 155 (3.0)

Subtotal American 396 (4.0) 322 (3.2) 271 (2.7) 272 (2.7) 326 (3.3) 284 (2.8) 273 (2.7)

TNF Total 2408 (5.9) 1851 (4.5) 1558 (3.8) 1576 (3.9) 1902 (4.7) 1679 (4.1) 1577 (3.9)

Percent Reduction 

by Alternative

23% 34% 35% 21% 30% 35%

Proposed Routes with Documented Erosional Features

Field surveys measured the amount of existing erosional features. Table 3.02-20 shows the existing 

erosional features found by alternative. Alternative 1 uses an estimate of the miles of erosion based on the 

percentage of erosion found during surveys times the miles of unauthorized routes and ML 1 routes 

receiving unauthorized use.

Table 3.02-20. Erosional features (miles) on proposed routes by alternative.

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Tahoe National Forest 250 54.1 0 19.1 54.1 41.7 38.4

Proposed Native Surface Road and Motorized Trail Route Density –

Erosion/Sedimentation Risk

All action alternatives would lower densities of native surface roads and motorized trails on the Tahoe 

National Forest 21 to 32 percent. Table 3.02-21 shows the density of native surface roads and motorized 

trails by major river basin by alternative. The No Action Alternative (Alternative 1) has the highest 

densities of native surface roads and motorized trails used by motorized vehicles. Alternatives 3, 4 and 7 

would have the lowest route density (1.9 mi/sq/mi) of motorized use on native surface roads and 

motorized trails. Alternative 6 densities would be slightly higher than Alternatives 3, 4 and 7. Of the 

action alternatives, Alternatives 2 and 5 would result in the highest route densities (2.2 mi/sq.mi). 

Alternative 6 would result in a density of 2.0 mi/sq.mi.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

Tahoe National Forest – 139

Table 3.02-21. Density of “Higher Risk Routes” by major river basin by alterative (mi./sq. mi.)

River Basin EMDS Erosion Risk

( risk quartile (0-25%, 

25-50%, 50-75%, 75-

100%))

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Middle Truckee River 0.58 (Lowest) 4.4 3.9 3.8 3.8 3.9 3.9 3.8

Little Truckee River 0.65 (Lowest) 2.9 2.2 1.9 1.9 2.2 2.1 1.9

Subtotal Truckee River 0.61 (Lowest) 3.7 3.1 2.9 2.9 3.1 3.0 2.9

Feather River 0.62 (Lowest) 2.6 1.7 1.5 1.5 1.7 1.6 1.5

North Yuba River 0.40 (Highest) 2.5 1.8 1.4 1.5 2.0 1.5 1.5

Middle Yuba River 0.44 (Higher) 2.8 2.2 2.1 2.1 2.2 2.1 2.1

South Yuba River 0.48 (Lower) 2.7 2.2 2.0 2.0 2.3 2.1 2.0

Subtotal Yuba 0.44 (Higher) 2.7 2.1 1.8 1.8 2.2 1.9 1.8

Bear River 0.44 (Higher) 3.7 3.1 2.7 2.8 3.1 2.9 2.8

North Fork American River 0.45 (Higher) 2.5 1.8 1.6 1.6 1.9 1.7 1.6

Middle Fork American River 0.42 (Higher) 2.0 1.6 1.5 1.5 1.6 1.6 1.5

Subtotal American 0.43 (Higher) 2.2 1.7 1.5 1.5 1.7 1.6 1.5

TNF Total 0.48 (Lower) 2.8 2.2 1.9 1.9 2.2 2.0 1.9

% reduction 21% 32% 32% 21% 29% 32%

Existing native surface road and motorized trail route densities were divided into quartiles (25% in 

each density class) to track proposed changes in route density. So the HUC6 watersheds with the lowest 

25 percent EMDS erosion risk scores represent the watersheds on the TNF with the lowest risk of 

motorized routes related erosion. Table 3.02-21 shows that forest-wide there is a decrease in native 

surface road and motorized trail density of 21 to 32 percent from implementing any of the Action 

Alternatives. On the eastside of the Tahoe, where erosion risks are the lowest on the Forest, native surface 

road and motorized trail density would decrease by 16 to 22 percent in the Truckee River basin and 35 to 

42 percent in the Feather River basin (Sierra Valley). On the Westside of the Forest, where erosion risks 

are the highest, there would be a decrease of 18 to 33 percent in the Yuba River basin, 16 to 27 percent in 

the Bear River basin, and 22 to 31 percent in the American River basin. The North Yuba River sub-basin 

has the highest erosion risk on the Forest. Native surface road and motorized trail density would decrease 

by 20 to 40 percent in the Action alternatives.

Figure 3.02-5 and Table 3.02-22 show the percent of the HUC6 watersheds on the TNF by 

Alternative and native surface road and motorized trail density class. Currently 25 percent of the HUC6 

watersheds on the TNF have a native surface road and motorized trail density of 3.5 to 6.5 miles per 

square mile. All of the action alternatives would decrease the HUC6 watersheds in this density class by 12 

to 17 percent. There would be an increase in the HUC6 watersheds within the lowest existing density 

class (0.8-2.3) of 21 to 44 percent with implementation of the action alternatives.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

140 – Tahoe National Forest

Figure 3.02-5. Native surface roads and motorized trails by alternative and density class

Table 3.02-22. Native surface roads and native trails by Alternative and Density Class

Existing Density Class % of HUC6 watersheds by high risk route density class by Alt

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

3.5 to 6.5 25% 12% 10% 8% 13% 12% 8%

2.8 to 3.5 25% 15% 8% 10% 13% 6% 10%

2.3 to 2.8 25% 17% 13% 13% 21% 23% 13%

0.8 to 2.3 25% 56% 69% 69% 52% 60% 69%

Equivalent Road Acres Analysis

All action alternatives decrease the ERAs associated with roads and trails on the TNF including long-term 

recovery of undesignated routes (see Table 3.02-23).

"Higher Risk Route Density" by Alternative

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Alternatives

Percent of HUC6 Watersheds

0.78 to 2.26

2.27 to 2.77

2.78 to 3.53

3.54 to 6.50
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

Tahoe National Forest – 141

Table 3.02-23. Equivalent Road Acres associated with roads and trails due to cumulative effects of all 

proposed actions (ERA percents of watershed)

River Basin Basin 

Acres

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Middle Truckee River 118,238 2,417.6 

2.05%

2,241.0 

1.90%

2,239.0 

1.89%

2,240.8

1.90%

2,242.4 

1.90%

2,245.3 

1,90%

2,240.5 

1.90%

Little Truckee River 109,1558 1,329.1 

1.22%

1,182.6 

0.99%

1,066.3 

0.98%

1,074.2 

0.98%

1,095.1 

1.00%

1,087.1 

1.00%

1,072.8 

0.98%

Subtotal Truckee

River

227,393 3,746.7 

1.65%

3,423.6 

1.46%

3,305.3 

1.45%

3,315.0 

1.46%

3,337.5 

1,47%

3,332.4 

1.47%

3,313.3 

1.46%

Feather River 249,750 2,726.7 

1.09%

2,067.2 

0,83%

2,063.1 

0.83%

2,064.2 

0.83%

2,078.8 

0,83%

2,072.7 

0.83%

2,060.6 

0.83%

North Yuba River 229,995 2,469.8 

1.07%

1,923.5 

0.84%

1,902.5 

0.83%

1,906.0

0.83%

2,043.3 

0.89%

1,922.4 

0.84%

1,913.0 

0.83%

Middle Yuba River 126,370 1,757.9 

1.39%

1,530.8 

1.21%

1,528.6 

1.21%

1,529.9 

1.21%

1,536.4 

1.22%

1,533.3 

1.21%

1,529.4 

1.21%

South Yuba River 174,566 2,123.7 

1.22%

1,798.6 

1.03%

1,781.1 

1.02%

1,785.2 

1.02%

1,806.8 

1.04%

1,799.7 

1.03%

1,789.5 

1.03%

Subtotal Yuba River 530,932 6,351.4 

1.20%

5,252.9 

0.99%

5,212.3 

0.98%

5,221.2 

0.98%

5,386.4 

1.02%

5,255.4 

0.99%

5,231.9 

0.99%

Bear River 23,310 343.7 

1.48%

290.0 

1.24%

288.4 

1.24%

290.0 

1.24%

293.2 

1.26%

290.6 

1.25%

290.0 

1.24%

Middle Fork American 

River

153,368 1,570.2 

1.02%

1,241.6 

0.81%

1,238.6 

0.81%

1,239.5 

0.81%

1,264.9 

0.83%

1,245.9 

0.81%

1,240.2 

0.81%

North Fork American 

River

140,869 1,165.8 

0.83%

958.0 

0.68%

952.1 

0.68%

955.6 

0.68%

965.2 

0.69%

958.6 

0.68%

957.2 

0.68%

Subtotal American 

River

294,237 2,726.0 

0.93%

2,199.7 

0.75%

2,190.7 

0.75%

2,195.1 

0.75%

2,230.1 

0.76%

2,204.5 

0.75%

2,197.4

0.75%

Total TNF 1,325,623 16,030.1 

1.21%

13,353.7 

1.00%

13,179.5 

0.99%

13,205.9 

1.00%

13,446.3 

1.01%

13,275.9 

1.00

13,219.6 

1.00%

Environmental Consequences by Alternative

Alternative 1 – No action

• Prohibition of Cross Country Motor Vehicle Travel: Cross country travel would not be 

prohibited in Alternative 1 on 717,900 acres. Cross country travel is currently prohibited on 

86,500 acres. It is likely that cross-county travel would result in an increase in the motorized 

footprint on the TNF. Cross country travel would continue on approximately 1,081miles of native 

surface, motorized unauthorized routes and ML 1 routes receiving unauthorized use (207 miles in 

RCAs). This could impact hydrology resources by increasing erosion, sediment production and 

delivery to streams which could decrease water quality.

• Additions to the NFTS. There are no additions of routes to the NFTS under this alternative.

• Establishment of motorized “Open Areas”. There are no establishments of “Open Areas” under 

this alternative.

• Changes to the existing NFTS. There are no changes to vehicle class and/or season of use to the 

NFTS under this alternative. No Maintenance Level (ML) 1 Roads are reopened with this 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

142 – Tahoe National Forest

alternative; however, cross country motorized use is allowed, so the net effect would be that use of 

some ML 1 route would probably occur.

• Forest Plan Amendment: There are no changes to the Forest Plan with this alternative.

• Cumulative Effects

 There are 2,649 acres of “Open Areas” in RCAs (Greenhorn Area – 60 acres; Boca, Prosser, 

and Stampede Reservoir access – 2,589 acres)

 There is a total of 1,080.5 miles of native surface roads and motorized trails in RCAs on the 

TNF.

 There are 2,462 perennial and intermittent crossings on the TNF.

 There is an estimated 250 miles of routes on the Forest with erosional features (Based on 

percent of erosional features found during route surveys for this project).

 The ERAs associated with the NFTS are 16,030.

Alternative 2 – Increased Motorized Recreation and Access Opportunities

• Prohibition of Cross Country Motor Vehicle Travel: Public wheeled motor vehicle travel off 

designated NFTS roads, NFTS trails, and outside established motorized use areas would be 

prohibited, except as allowed by permit or other authorization. This would prohibit the 

proliferation of new routes and prohibit motorized use on all unauthorized and closed system 

routes not added to the NFTS. This could reduce erosion and subsequent sediment delivery to 

waterbodies associated with motorized use on the TNF.

• Additions to the NFTS. Adding 2.6 miles of roads in RCAs and 9.7 miles of trails in RCAs to the 

NFTS would have minimal effects to hydrology resources. These are pre-existing routes so no new 

soil compaction/disturbance would be created. These route additions would be subject to FS 

standards.

• Establishment of motorized “Open Areas” Four “Open Areas” totaling 2,649 acres would be 

established in the Bear River basin (Greenhorn Area at 60 acres) and the Truckee River basin 

(Prosser, Boca and Stampede Reservoirs at 2,589 acres). These areas are currently being used as 

“Open Areas” even though they are not established “Open Areas”. Localized effects to hydrology

resources in these areas have been reported especially during wet season use.

• Changes to the existing NFTS.

 Change Vehicle Classes through Mixed Use: Approving mixed use on 241.5 miles would not 

affect hydrology resources.

 Change Vehicle Classes through Maintenance Levels: Changing vehicle class on 34.3 miles 

of routes in RCAs to allow licensed operators of non-highway legal vehicles to operate on NFS 

roads where such use is currently prohibited through the conversion of ML 3 roads to ML 2 

would have minimal effects to watershed resources. These are pre-existing “routes.” As NFTS 

routes, these routes would be subject to FS standards.

 Changes in Seasonal Restrictions: Seasonal restrictions for deer winter range would be lifted 

on 1.6 miles of roads in RCAs resulting from the Forest Plan Amendment to Management Area 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

Tahoe National Forest – 143

84 (Humbug-Sailor) which would slightly increase the risk of wet season damage to these 

roads and adjacent watersheds.

 Reopening Maintenance Level 1 Roads: No ML 1 roads would be opened to motorized use.

• Forest Plan Amendment: There would be the same effects as the Seasonal Restrictions above.

• Cumulative Effects: The short-term cumulative effects of Alternative 2 would be minimal. The 

long-term cumulative effects of Alternative 2 would decrease the NFTS hydrologic footprint and 

effects to watershed resources.

 There would be 2,649 acres of “Open Areas” in RCAs (Greenhorn Area; Boca, Prosser, and 

Stampede Reservoir access). 

 There would be a total of 772 miles of native surface roads and motorized trails in RCAs on the 

TNF (density =0.7 mi./sq.mi.). 

 There would be 1,689 perennial and intermittent crossings.

 There are 54.1 miles of routes on the Forest proposed for addition to the NFTS with 

documented erosional features. These erosion features would be mitigated prior to opening for 

motorized use.

 The ERAs associated with the NFTS would be 13,254.

Alternative 3 – Cross country Travel Prohibition Only – No Changes to the 

Existing National Forest Transportation System

• Prohibition of Cross Country Motor Vehicle Travel: Public wheeled motor vehicle travel off 

designated NFTS roads, NFTS trails, and outside established motorized use areas would be 

prohibited, except as allowed by permit or other authorization. This would prohibit the 

proliferation of new routes and prohibit motorized use on all unauthorized and closed system 

routes not added to the NFTS. This could reduce erosion and subsequent sediment delivery to 

waterbodies associated with motorized use on the TNF.

• Additions to the NFTS. No unauthorized routes would be added to the NFTS as roads or 

motorized trails under this alternative

• Establishment of motorized “Open Areas” No additional motorized “Open Areas” would be 

established under this alternative.

• Changes to the existing NFTS - this includes changing the vehicle class and/or season of use 

and reopening ML 1 Roads. No Changes to the NFTS would be made in this alternative.

• Forest Plan Amendment: No amendments would be made to the Forest Plan.

• Cumulative Effects: The short-term cumulative effects of Alternative 3 would be minimal. The 

long-term cumulative effects of Alternative 3 would decrease the NFTS hydrologic footprint and 

effects to watershed resources.

 There are 0.0 miles of unauthorized native surface roads and motorized trails in RCAs 

proposed for addition to NFTS.

 There would be 0 acres of “Open Areas” in RCAs (Greenhorn Area; Boca, Prosser, and 

Stampede Reservoir access).
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

144 – Tahoe National Forest

 There would be a total of 725.8 miles of native surface roads and motorized trails in RCAs on 

the TNF (density = 0.7 mi./sq.mi.). 

 There would be 1,558 perennial and intermittent crossings.

 There are 0.0 miles of routes on the Forest proposed for addition to the NFTS with documented 

erosional features. 

 The ERAs associated with the NFTS would be 13,180.

Alternative 4 – Increased Resource Protection

• Prohibition of Cross Country Motor Vehicle Travel: Public wheeled motor vehicle travel off 

designated NFTS roads, NFTS trails, and outside established motorized use areas would be 

prohibited, except as allowed by permit or other authorization. This would prohibit the 

proliferation of new routes and prohibit motorized use on all unauthorized and closed system 

routes not added to the NFTS. This could reduce erosion and subsequent sediment delivery to 

waterbodies associated with motorized use on the TNF.

• Additions to the NFTS. Adding 1.7 miles of roads in RCAs and 3.7 miles of trails in RCAs to the 

NFTS would have minimal effects to hydrology resources. These are pre-existing routes so no new 

soil compaction/disturbance would be created. These route additions would be subject to FS 

standards.

• Establishment of motorized “Open Areas” No additional motorized “Open Areas” would be 

established under this alternative.

• Changes to the existing NFTS.

 Change Vehicle Classes through Mixed Use: No changes would be made to allow licensed 

operators of non-highway legal vehicles to operate on NFS roads where such use is currently 

prohibited through approval of mixed use.

 Change Vehicle Classes through Maintenance Levels: Changing vehicle class on 2.0 miles

or routes in RCAs to allow operators of non-highway legal vehicles to operate on NFS roads 

where such use is currently prohibited through the conversion of ML 3 roads to ML 2 would

have minimal effects to hydrology resources. These are pre-existing “routes.” As NFTS routes,

these routes would be subject to FS standards.

 Changes in Seasonal Restrictions: Wet weather seasonal closures from January 1 to May 31 

in the Burlington area and January 1 to April 30 on the remainder of the Forest on native 

surface roads and motorized trails would be added to minimize erosion and protect water 

quality. A total of 245.8 total miles in RCAs would have changes in seasonal restrictions.

Seasonal restrictions would decrease the risk of increased erosion and sediment deliver to 

water bodies associated with wet season route damage due to motorized use.

 Reopening Maintenance Level 1 Roads: Reopening 0.1 miles on one ML 1 road in RCAs to 

motorized use would not affect long-term hydrology resources. Closed NFTS routes that are 

proposed to be opened are roads that were engineered to control drainage and erosion and are 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.02. Watershed Resources: Geology, Soil, Hydrology

Tahoe National Forest – 145

thus designed to minimize stream sedimentation. They are expected to receive maintenance 

when opened.

• Forest Plan Amendment: No amendments would be made to the Forest Plan.

• Cumulative Effects: The short-term cumulative effects of Alternative 4 would be minimal. The 

long-term cumulative effects of Alternative 4 would decrease the NFTS hydrologic footprint and 

effects to watershed resources.

 There would be 0 acres of “Open Areas” in RCAs (Greenhorn Area; Boca, Prosser, and 

Stampede Reservoir access).

 There would be a total of 733.3 miles of native surface roads and motorized trails in RCAs on 

the TNF (density =0.7 mi./sq.mi.). 

 There would be 1,576 perennial and intermittent crossings on the TNF.

 There are 19.1 miles of routes on the Forest proposed for addition to the NFTS with 

documented erosional features. These erosion features would be mitigated prior to opening for 

motorized use.

 The ERAs associated with the NFTS would be 13,206.

Alternative 5 – Increased Motorized Recreation Access plus Reopening 

Maintenance Level 1 and Temporary Roads

• Prohibition of Cross Country Motor Vehicle Travel: Public wheeled motor vehicle travel off 

designated NFTS roads, NFTS trails, and outside designated motorized use areas would be 

prohibited, except as allowed by permit or other authorization. This would prohibit the 

proliferation of new routes and prohibit motorized use on all unauthorized and closed system 

routes not added to the NFTS. This could reduce erosion and sediment delivery to waterbodies 

associated with motorized use on the TNF.

• Additions to the NFTS. Adding 2.6 miles of roads in RCAs and 13.7 miles of trails in RCAs to 

the NFTS would have minimal effects to soil resources. These are pre-existing routes so no new 

soil compaction/disturbance would be created. These route additions would be subject to FS 

standards.

• Establishment of motorized “Open Areas” No additional motorized “Open Areas” would be 

established under this alternative.

• Changes to the existing NFTS.

 Change Vehicle Classes through Mixed Use: Changing vehicle class on 241.5 miles to allow 

licensed operators of non-highway legal vehicles to operate on NFS roads where such use is 

currently prohibited through approval of mixed use would not affect hydrology resources.

 Change Vehicle Classes through Maintenance Levels: Changing vehicle class on 34.3 miles

of roads in RCAs to allow operators of non-highway legal vehicles to operate on NFS roads 

where such use is currently prohibited through the conversion of ML 3 roads to ML 2 would

have minimal effects to hydrology resources. These are pre-existing “routes.” As NFTS routes,

these routes would be subject to FS standards.
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146 – Tahoe National Forest

 Changes in Seasonal Restrictions: Wet weather seasonal closures from January 1 to May 31 

in the Burlington area and January 1 to April 30 on the remainder of the Forest on native 

surface roads and motorized trails would be added to minimize erosion and protect water 

quality. A total of 263.1miles of routes in RCAs would have changes in seasonal restrictions.

 Reopening Maintenance Level 1 Roads: Reopening 14.8 miles on 113 ML 1 roads in RCAs

to motorized use would have a small affect on hydrology resources where the routes are 

reopened. Closed NFTS routes that are proposed to be opened are roads that were engineered 

to control drainage and erosion and are thus designed to minimize stream sedimentation. They 

are expected to receive maintenance when opened.

• Forest Plan Amendment: There would be the same effects as the Seasonal Restrictions above.

• Cumulative Effects: The short-term cumulative effects of Alternative 5 would be minimal. The 

long-term cumulative effects of Alternative 5 would decrease the NFTS hydrologic footprint and 

effects to watershed resources.

 There would be 0 acres of “Open Areas” in RCAs (Greenhorn Area; Boca, Prosser, and 

Stampede Reservoir access). 

 There are 16.1 miles of unauthorized native surface roads and motorized trails routes in RCAs 

proposed for addition to NFTS.

 There would be 50.1 miles of ML 1 roads in RCAs reopened.

 There would be a total of 791 miles of native surface roads and motorized trails in RCAs on the 

TNF (density = 0.7 mi./sq.mi.). 

 There would be 1,740 perennial and intermittent crossings.

 There are 54.1 miles of routes on the Forest proposed for addition to the NFTS with 

documented erosional features. These erosion features would be mitigated prior to opening for 

motorized use.

 The ERAs associated with the NFTS would be 13,446.

Alternative 6 – Preferred Alternative Motorized Access and Resource Protection

• Prohibition of Cross Country Motor Vehicle Travel: Public wheeled motor vehicle travel off 

designated NFTS roads, NFTS trails, and outside designated motorized use areas would be 

prohibited, except as allowed by permit or other authorization. This would prohibit the 

proliferation of new routes and prohibit motorized use on all unauthorized and closed system 

routes not added to the NFTS. This could reduce erosion and subsequent sediment delivery to 

waterbodies associated with motorized use on the TNF.

• Additions to the NFTS. Adding 7.0 miles of roads in RCAs and 9.0 miles of trails in RCAs to the 

NFTS would have minimal effects to hydrology resources. These are pre-existing routes so no new 

soil compaction/disturbance would be created. These route additions would be subject to FS 

standards.

• Establish motorized “Open Areas” Three areas totaling 244 acres (Boca, Prosser, and Stampede 

Reservoir access) would be established as motorized “Open Areas” under this alternative.
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Tahoe National Forest – 147

• Changes to the existing NFTS.

 Change Vehicle Classes through Mixed Use: Changing vehicle class on 130.8 miles of roads 

in RCAs to allow licensed operators of non-highway legal vehicles to operate on NFS roads 

where such use is currently prohibited through approval of mixed use would not affect 

hydrology resources.

 Change Vehicle Classes through Maintenance Levels: Changing vehicle class on 25.2 miles 

of roads in RCAs to allow operators of non-highway legal vehicles to operate on NFS roads 

where such use is currently prohibited through the conversion of ML 3 roads to ML 2 would

have minimal effects to hydrology resources. These are pre-existing routes so the loss of 

productivity has already occurred. As NFTS routes, these routes would be subject to FS 

standards.

 Changes in Seasonal Restrictions: Wet weather seasonal closures from January 1 to May 31 

in the Burlington area and January 1 to April 30 on the remainder of the Forest on native 

surface roads and motorized trails would be added to minimize erosion and protect water 

quality. In addition, over the snow travel would be permitted on 3.6 miles of the Fordyce Jeep 

trail when 15 inches of snow is present on the ground. A total of 255.5 miles of routes in RCAs

would have changes seasonal restrictions.

 Reopening Maintenance Level 1 Roads: Reopening 2.2 miles of 13 ML 1 roads in RCAs to 

motorized use would have a small affect on hydrology resources where the routes are reopened. 

Closed NFTS routes that are proposed to be opened are roads that were engineered to control 

drainage and erosion and are thus designed to minimize stream sedimentation. They are 

expected to receive maintenance when opened.

 Forest Plan Amendment: There would be the same effects as the Seasonal Restrictions above.

• Cumulative Effects: The short-term cumulative effects of Alternative 6 would be minimal. The 

long-term cumulative effects of Alternative 6 would decrease the NFTS hydrologic footprint and 

effects to watershed resources.

 There would be 244 acres of “Open Areas” in RCAs (Boca, Prosser, and Stampede 

Reservoir access). 

 There would be a total of 769.2 miles of native surface roads and motorized trails in RCAs 

on the TNF (density =0.7 mi./sq.mi.). 

 There would be 244 acres of “Open Areas” in RCAs (Boca, Prosser, and Stampede 

Reservoir access). 

 There would be 1,676 perennial and intermittent crossings.

 There are 41.7 miles of routes on the Forest proposed for addition to the NFTS with 

documented erosional features. These erosion features would be mitigated prior to opening 

for motorized use.

 The ERAs associated with the NFTS would be 13,276.
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148 – Tahoe National Forest

Alternative 7 – Proposed Action as Identified in Notice of Intent (NOI)

• Prohibition of Cross Country Motor Vehicle Travel: Public wheeled motor vehicle travel off 

designated NFTS roads, NFTS trails, and outside designated motorized use areas would be 

prohibited, except as allowed by permit or other authorization. This would prohibit the 

proliferation of new routes and prohibit motorized use on all unauthorized and closed system 

routes not added to the NFTS. This could reduce erosion and subsequent sediment delivery to 

waterbodies associated with motorized use on the TNF.

• Additions to the NFTS. Under this alternative, adding 6.8 miles unauthorized trails in RCAs to 

the NFTS would have minimal effects to hydrology resources. These are pre-existing routes so no 

new soil compaction/disturbance would be created. These routes would be subject to FS standards.

• Establishment of motorized “Open Areas” No additional motorized “Open Areas” would be 

established under this alternative.

• Changes to the existing NFTS.

 Change Vehicle Classes through Mixed Use: No changes would be made to allow licensed 

operators of non-highway legal vehicles to operate on NFS roads where such use is currently 

prohibited through approval of mixed use.

 Change Vehicle Classes through Maintenance Levels: Changing vehicle class on 2.0 miles 

of roads in RCAS to allow operators of non-highway legal vehicles to operate on NFS roads 

where such use is currently prohibited through the conversion of ML 3 roads to ML 2 would

have minimal effects to hydrology resources. These are pre-existing “routes.” As designated 

routes within the NFTS these routes would be subject to FS standards.

 Changes in Seasonal Restrictions: No changes in seasonal restrictions would be made.

 Reopening Maintenance Level 1 Roads: Reopening two ML 1 roads (0.1 miles in RCAs) to 

motorized use may have a minor effect on hydrology resources. Closed NFTS routes that are 

proposed to be opened are roads that were engineered to control drainage and erosion and are 

thus designed to minimize stream sedimentation. They are expected to receive maintenance 

when opened.

• Forest Plan Amendment: No amendments would be made to the Forest Plan.

• Cumulative Effects: The short-term cumulative effects of Alternative 7 would be minimal. The 

long-term cumulative effects of Alternative 7 would decrease the NFTS hydrologic footprint and 

effects to watershed resources.

 There would be 0 acres of “Open Areas” in RCAs (Greenhorn Area; Boca, Prosser, and 

Stampede Reservoir access). 

 There would be a total of 734.6 miles of native surface roads and motorized trails in RCAs on 

the TNF (density =0.7 mi./sq.mi.). 

 There would be 1,577 perennial and intermittent crossings on the TNF.

 There are 38.4 miles of routes on the Forest proposed for addition to the NFTS with 

documented erosional features. These erosion features would be mitigated prior to opening for 

motorized use.
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Tahoe National Forest – 149

 The ERAs associated with the NFTS would be 13,220.

Summary of Effects to Hydrology Resources

Table 3.02-24 summarizes the effects analysis for hydrology resources by ranking each alternative 

regarding how well it provides for each of the indicators. This summary is not meant to convey that the 

indicators are equal in importance. The following rankings were used: A score of 7 indicates the 

alternative has the least impact for hydrology resources to the indicator. A score of 1 indicates the 

alternative has the most impact for hydrology resources related to the indicator.

Table 3.02-24. Comparison of Effects to Hydrology Resources

Indicators – Hydrology Resources Rankings of Alternatives for Each Indicator1

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Miles of unauthorized routes in hydrologically 

sensitive areas (RCAs).

1 0 0 0 0 0 0

Native Surface Roads and Motorized Trails in 

RCAs

Sum of the erosion potential in cubic yards or 

tons or route miles with existing erosional 

features on unauthorized routes and areas 

proposed for addition to the NFTS in 

hydrologically sensitive areas on the forest.

1 3 7 6 2 4 5

Numbers of locations where routes divert or have 

potential to divert streamflow. All Higher Risk 

Route crossings are assumed to have diversion 

potential.

1 3 7 6 2 4 5

Sum of route miles with documented erosional 

features.

1 2 7 6 2 5 6

Equivalent roaded areas in acres. 1 4 7 6 2 3 5

Prohibition on Cross County Travel 1 2 4 4 4 3 4

Seasonal Restrictions miles of routes 2 1 2 5 7 6 2

Native surface road and motorized trail density 1 3 5 6 2 4 6

Average for Water Resources 1.0 2.0 7.0 6.0 3.0 4.0 5.0

1 A score of 7 indicates the alternative has the least impact for water resources related to the indicator; A score of 1 indicates the 

alternative has the most impact for water resources related to the indicator.

Using the metrics from Table 3.02-24, Alternative 1 would have the highest potential impacts to 

hydrology resources. All of the action alternatives would have a similar potential impact to hydrology

resources. Included in Table 3.02-24 are the prohibition of cross country travel and the seasonal closures.

Because these two proposed actions cover the most of the TNF, they would greatly outweigh the proposed 

additions and changes to the NFTS. Taking into account the magnitude of impacts of the proposed 

prohibition of cross country travel and the seasonal closures, the alternatives would be ranked from 

highest potential impact to lowest: Alternative 1, Alternative 2, Alternative 7, Alternative 3, Alternative 5, 

Alternative 6, and then Alternative 4.
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150 – Tahoe National Forest

Summary of Effects to Geologic, Soil and Hydrology Resources

This project defines where motorized vehicle traffic use is authorized on the Tahoe National Forest.

Therefore, direct impacts to soils and adjacent watersheds and stream courses that result from this project 

are limited. There are no new ground disturbing activities proposed with this project. The roads, 

motorized trails and “Open Areas” being evaluated in this analysis already exist on the ground, but may 

require upgrading to NFTS standards as well as periodic maintenance. They are compacted and generally 

lack vegetation. Runoff from the surface is collected and discharged as potentially erosive flows at points 

below the road or motorized trail. Some are eroded or causing erosion, others are stable and are not 

causing any negative resource impacts. From the standpoint of soil productivity and growing vegetation, 

these roads, motorized trails and “Open Areas” are already non-productive. Therefore the potential effects 

on soil and watershed resources are related to sustaining road or trail function, protecting adjacent soils 

from runoff and gully erosion, protecting water quality, or restoring the routes to a productive state. Given 

that Alternative 1 (no action) the existing hydrologic footprint is the largest proposed, all action 

alternatives would reduce the footprint of motorized use.

It should be noted that although many roads and motorized trails on the TNF have some site specific 

risks to geology, soil and/or water resources, most of these risks can be mitigated. The field surveys 

performed for this assessment found site specific concerns to be mitigated, but with regular maintenance 

and control of wet season use the roads, motorized trails and “Open Areas” seem to be sustainable. All 

known erosional sites would be fully mitigated before shown on the MVUM, so that adverse effects of 

adding new routes would be minimized.

Conclusion

All of the action alternatives meet existing standards and guidelines, laws, and policies. Prohibition of

cross country travel and wet season closures are the two most important potential actions proposed in this 

project. Prohibiting cross country travel would limit the expansion of the road and trail related disturbance 

footprint. Equally as important in limiting the negative effects of motorized travel on geologic, soil and 

hydrology resources, is the wet season closure. The positive effects of these two actions would far 

outweigh the proposed additions of motorized trails to the NFTS or the changes in vehicle class. The 

order of potential cumulative effect of the alternatives, from highest potential to lowest potential, would 

be Alternative 1, Alternative 2, Alternative 7, Alternative 3, Alternative 5, Alternative 6, and then 

Alternative 4.
Chapter 3.03 

Terrestrial & 

Aquatic Species 

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Tahoe National Forest – 151

3.03. Terrestrial and Aquatic Species _______________________

Introduction

Management of wildlife species and habitat, and maintenance of a diversity of animal 

communities is an important part of the mission of the Forest Service (Resource Planning Act of 

1974, National Forest Management Act of 1976). Management activities on National Forest 

System (NFS) lands are planned and implemented so that they do not jeopardize the continued 

existence of threatened or endangered species or lead to a trend toward listing or loss of viability 

of Forest Service Sensitive species. In addition, management activities should be designed to 

maintain or improve habitat for Management Indicator Species to the degree consistent with 

multiple-use objectives established in each Forest Land and Resource Management Plan (LRMP). 

Management decisions related to public motorized travel can affect wildlife by increasing humancaused mortality, causing changes in behavior due to disturbance, and habitat modification 

(Gaines et al. 2003, Trombulak and Frissell 2000, USDA Forest Service 1998). It is Forest 

Service policy to minimize damage to vegetation, avoid harassment to wildlife, and avoid 

significant disruption of wildlife habitat while providing for motorized public use on NFS lands 

(FSM 2353.03(2)). Therefore, management decisions related to public motorized travel on NFS 

lands must consider effects and wildlife and their habitat.

Analysis Framework: Statute, Regulation, Forest Plan

and Other Direction

Management direction relevant to the Proposed Action as it affects terrestrial and aquatic biota 

includes:

• Endangered Species Act (ESA): The Endangered Species Act of 1973 (16 USC 1531 et 

seq.) requires that any action authorized by a federal agency not be likely to jeopardize the 

continued existence of a threatened or endangered (TE) species, or result in the destruction 

or adverse modification of habitat of such species that is determined to be critical. Section 

7 of the ESA, as amended, requires the responsible federal agency to consult the USFWS 

and the National Marine Fisheries Service concerning TE species under their jurisdiction. 

It is Forest Service policy to analyze impacts to TE species to ensure management 

activities are not be likely to jeopardize the continued existence of a TE species, or result 

in the destruction or adverse modification of habitat of such species that is determined to 

be critical. This assessment is documented in a Biological Assessment (BA) and is 

summarized or referenced in this Chapter. 

• Bald and Golden Eagle Protection Act, Migratory Bird Treaty Act: The bald eagle was 

listed by the USDI Fish and Wildlife Service as a federally endangered species under the 

Endangered Species Act in 1978, reclassified to Threatened status in 1995, and delisted in 

2007. Even though they are delisted, bald eagles are still protected by the Migratory Bird 

Treaty Act and the Bald and Golden Eagle Protection Act. These Acts require some 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

152 – Tahoe National Forest

measures to prevent bald eagle “take” resulting from human activities. Following 

delisting, the bald eagle was placed on the Region 5 Regional Forester’s Sensitive Species 

List (USDA Forest Service 1999). In the sections below, this document and the Biological 

Evaluation for the Tahoe NF Motorized Travel Management Project, which is 

incorporated by reference, analyzes and discloses effects of the alternatives.

• Migratory Landbird Conservation on the Tahoe National Forest: Within the National Forests, 

conservation of migratory birds focuses on providing a diversity of habitat conditions at multiple 

spatial scales and ensuring that bird conservation is addressed when planning for land 

management activities.

As part of the Travel Management process, the Tahoe National Forest has conducted an 

assessment of existing roads and trails within Forest boundaries. Any new construction, 

reconstruction and maintenance of system roads or trails will be conducted under a separate NEPA 

analysis and decision. Because current travel management efforts are directed at identifying which 

existing unauthorized routes will be formally added to the NFTS while prohibiting cross country

travel, and because there is no expectation of new construction or development, no changes in the 

distribution or abundance of habitats available to migratory birds are anticipated. Changes in 

authorization are not anticipated to contribute to measurable increases in use levels, but the 

prohibition of cross country travel is expected to result in less use across the landscape. Therefore 

habitat functionality and levels of disturbance related to use are expected to remain similar to or 

less than pre-decisional levels.

• Forest Service Manual and Handbooks (FSM/H 2670): Forest Service Sensitive (FSS) species 

are animal and plant species identified by the Regional Forester for which population viability is a 

concern. The Forest Service develops and implements management practices to ensure that rare 

plants and animals do not become threatened or endangered and ensure their continued viability on 

national forests. It is Forest Service policy to analyze impacts to sensitive species to ensure 

management activities do not create a significant trend toward federal listing or loss of viability. 

This assessment is documented in a Biological Evaluation (BE) and is summarized and referenced 

in this Chapter.

• Sierra Nevada Forest Plan Amendment (SNFPA): The Record of Decision (ROD) for the 2004 

Sierra Nevada Forest Plan Amendment identified the following standards and guidelines 

applicable to motorized travel management and terrestrial biota, which will be considered during 

the analysis process: 

 Wetland and Meadow Habitat (Management Standard & Guideline 70): Avoid wetlands or 

minimize effects to natural flow patterns in wetlands and avoid road construction in meadows.

 California Spotted owl and Northern Goshawk: Evaluate proposals for new roads, trails, off 

highway vehicle routes, and recreational and other developments for their potential to disturb 

nest sites (Management Standard & Guideline 82). 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 153

 Fisher and Marten: Evaluate proposals for new roads, trails, off highway vehicle routes, and 

recreational and other developments for their potential to disturb den sites (Management 

Standard & Guidelines 87 and 89). 

• Riparian Habitat:

 Evaluate new proposed management activities within CARs and RCAs during environmental 

analysis to determine consistency with the riparian conservation objectives (RCOs) at the 

project level and the AMS goals for the landscape. Ensure that appropriate mitigation measures 

are enacted to (1) minimize the risk of activity-related sediment entering aquatic systems and 

(2) minimize impacts to habitat for aquatic- or riparian-dependent plant and animal species 

(Management Standard & Guideline 92).

 As part of project-level analysis, conduct peer reviews for projects that proposed grounddisturbing activities in more than 25 percent of the RCA or more than 15 percent of a CAR 

(Management Standard & Guideline 94).

 Maintain and restore the hydrologic connectivity of streams, meadows, wetlands, and other 

special aquatic features by identifying roads and trails that intercept, divert, or disrupt natural 

surface and subsurface water flow paths. Implement corrective actions where necessary to 

restore connectivity (RCO#2, Management Standard & Guideline 100).

 Ensure that culverts or other stream crossings do not create barriers to upstream or downstream 

passage for aquatic-dependent species. Locate water drafting sites to avoid adverse effects to in 

stream flows and depletion of pool habitat. Where possible, maintain and restore the timing, 

variability, and duration of floodplain inundation and water table elevation in meadows, 

wetlands, and other special aquatic features (RCO#2, Management Standard & Guideline 101).

 Prior to activities that could adversely affect streams, determine if relevant stream 

characteristics are within the range of natural variability. If characteristics are outside the range 

of natural variability, implement mitigation measures and short-term restoration actions needed 

to prevent further declines or cause an upward trend in conditions. Evaluate required long-term 

restoration actions and implement them according to their status among other restoration needs 

(RCO#2, Standard and Guideline 102).

 Identify roads, trails, OHV trails and staging areas, developed recreation sites, dispersed 

campgrounds, special use permits, grazing permits, and day-use sites during landscape 

analysis. Identify conditions that degrade water quality or habitat for aquatic and ripariandependent species. At the project level, evaluate and consider actions to ensure consistency 

with standards and guidelines or desired conditions (RCO#3, Management Standard and 

Guideline 116).

• Management Indicator Species(MIS) (1982 Planning Rule) (36 CFR 219): Management 

indicator species are animal species identified in the 2007 Sierra Nevada Forest MIS Amendment 

Record of Decision, which was developed under the 1982 National Forest System Land and 

Resource Management Planning Rule (1982 Planning Rule) (36 CRF 219). Guidance regarding 
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154 – Tahoe National Forest

management indicator species (MIS) set forth in the Tahoe NF LRMP as amended by the Sierra 

Nevada Forests Management Indicator Species Amendment (SNF MIS Amendment) Record of 

Decision (USDA Forest Service 2007a) directs Forest Service resource managers to (1) at the 

project scale, analyze the effects of proposed projects on the habitat of each MIS affected by such

projects, and (2) at the bioregional scale, monitor populations and/or habitat trends of MIS. 

Although, the 2007 SNF MIS Amendment exempted the Tahoe NF Motorized Travel Management 

Project from adopting the newly amended MIS list, the ROD provides the deciding officer the 

discretion to elect to apply the new project-level analysis requirements. The Tahoe NF Forest 

Supervisor has elected to apply the new project-level analysis requirements to this project. 

Therefore, in the sections below, this document and the Tahoe NF Travel Management ProjectLevel MIS report, which is hereby incorporated by reference, evaluates and discloses the impacts 

of the alternatives on the habitat of the twelve (12) Management Indicator Species (MIS) 

identified in the Tahoe NF LRMP (USDA 1990) as amended by the 2007 SNF MIS Amendment 

ROD.

• Tahoe NF Land and Resource Management Plan (Tahoe LRMP): The Record of Decision 

(ROD) for the 1990 Tahoe LRMP identified the following standards and guidelines applicable to 

motorized travel management and terrestrial biota, which will be considered during the analysis 

process: 

• Deer Habitat Management (Management standard and guideline): Limit vehicle access on 

key deer winter ranges when deer are present. Also limit vehicle access in key summer range 

habitats during periods of migration and fawning. Retain or establish roadside screening along 

open roads in areas important for migration, fawning, or concentrated seasonal use.

• Meadow Edge Habitat (Management standard and guideline): Locate roads away from 

meadow edges where alternative routes are available.

Additional species-specific standards and guidelines are identified below under species effects 

analysis.

Background on Effects to Terrestrial and Aquatic Habitat

In recent years, the increasing demand for motorized recreational opportunities on NFS lands has lead to 

controversy over the potential effects of this use on wildlife. Several scientific papers and literature 

reviews have been written on the interaction between the motorized roads and trails on terrestrial and 

aquatic wildlife species. The majority of the literature and reviews describe the interactions between 

wildlife and roads rather than wildlife and trails. Most of the research has focused on wide-ranging 

carnivores and ungulates (hoofed animals). Most commonly, interactions included displacement and 

avoidance where animals were reported as altering their use patterns in response to roads. Disturbance at 

specific sites are also commonly reported, such as disruption at breeding or wintering sites. Collision with 

vehicles is another common report. Edge effects and habitat fragmentation, especially in regard to lateseral coniferous forests is another commonly identified impact of roads.
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The broad general impacts of motorized roads and trails to wildlife and aquatic species are described 

below (Trombulak and Frissell 2000):

• Increased terrestrial and aquatic species mortality from collision with vehicles

• Modification of animal behavior

• Alteration of the terrestrial and aquatic habitat

• Increased alteration and use of habitats by humans

These general impacts are included in the analysis procedure discussed in the Effects Analysis 

Methodology section. The causal factors are classified in that section as Disturbance, Habitat 

Modification, and Mortality. 

Mortality from Collisions with Vehicles

Animal mortality or injury from collision with vehicles is well documented in the literature. Trombulak 

and Frissell (2000) reported animal mortality from vehicle collisions included a wide array of wildlife 

including deer, wolves, bear, hawks, owls, songbirds, snakes, lizards, and amphibians. Road associated 

mortally generally increases as traffic volume and speed increases. For large mammals, unpaved forest 

roads pose less of a concern of mortality or injury from vehicle related collisions. However, amphibians 

may be especially vulnerable to road collision mortality because their life history involves movement 

between wetland and upland habitats, and amphibians are inconspicuous and sometimes slow-moving 

(Trombulak and Frissell 2000). Raptors may also be vulnerable to collisions from forest roads and trails 

because of their foraging behavior (Loos and Kerlinger 1993); however, the most reports of raptor 

mortality are in association with highways.

Road and trail corridors may act as habitat sinks for wildlife that are attracted to corridors (Jalkotzy et 

al. 1997). Direct mortality of animals from vehicle collisions has been documented primarily in relation to 

paved roads and highways. Little scientific information is available about vehicle collisions on forest 

roads or motorized trails, though some mortality from use of forest roads and motorized trails is to be 

expected depending on the type of trail and the amount of use a trail receives.

Indirect mortality along roads and trails is associated with human access. Wildlife populations of 

hunted and trapped species are subject to increased mortality due to better access by humans. Interiorforest birds breeding adjacent to roads and trails may receive higher nest predation by a variety of bird 

and mammal predators and some songbird species have shown to have increased brown-headed cowbird 

parasitism rates.

Modification of Animal Behavior

A road or trail may modify the behavior of animals positively or negatively. Behavior modifications 

include changes or shifts in home range, changes in movement patterns, loss of reproductive success, 

flight or escape response, and changes in physiological condition. Some wildlife species are more 

sensitive to well-traveled roads as opposed to motorized roads and trails that are only used by high 

clearance 4-wheel drive, motorcycle and all-terrain vehicles (ATVs). Other wildlife is more sensitive to 
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156 – Tahoe National Forest

the latter. In general, all roads and trails, depending on the type of vehicle and the amount of use, have 

some type of positive or negative impact of wildlife.

The most common interaction identified in literature between motorized roads and trails and wildlife 

species were displacement and avoidance, which altered habitat use (Kasworm and Manley 1990, Mace et 

al. 1996 In: Gaines et al. 2003). Wildlife often avoids habitats in the vicinity of roads because of repeated 

disturbances along the corridor (Jalkotzy, et al. 1997). Studies indicated both black bears and grizzly bears 

shifted their home ranges away from areas of high road density to areas of lower road densities (Brody & 

Pelton 1989, McLellan & Shackelton 1988). Road avoidance may vary seasonally. Both grizzly and black 

bears tended to avoid roads less in the spring than in the fall. Elk also avoided roads less in the spring and 

more in the fall.

Roads may affect the reproductive success of some species. Bald eagles in Oregon and Illinois 

showed declines in nesting productivity the closer the proximity to roads. Bald eagle nests were 

preferentially selected away from roads (Trombulak and Frissell 2000).

Havlick (2002) documented numerous studies that show wildlife, including birds, reptiles, and large 

ungulates, respond to disturbance with accelerated heart rate and metabolic function, and suffer from 

increased levels of stress. These factors can lead to displacement, mortality, and reproductive failure. 

Wildlife was also reported to avoid areas with high levels of disturbance.

The impacts of motorized vehicles to terrestrial wildlife can include disturbance from noise generated 

by OHVs. Determining the effects of noise on wildlife is complicated because responses vary between 

species. The variation in responses is based upon the type of noise and its duration, frequency, the 

magnitude, location, the species life history characteristics, habitat type, season, activity at time of 

exposure, and whether other environmental stresses are occurring coincident to exposure of noise (Busnel 

1978 In: Radle 1999, Steidl and Powell 2006). Effects of noise can cause physiological responses in 

wildlife including increased heart rate and altering metabolism and hormone balance. Behavioral 

responses can include head raising, body shifting, short distance movements, flapping of wings (birds), 

and escape behavior. Together these effects potentially can lead to bodily injury, energy loss, decrease in 

food intake, habitat avoidance and abandonment, and reproductive loss. The vast majority of studies 

conducted on wildlife effects from road and trail-associated noise has been done for bird species.

Many studies have reported interactions between roads and ungulates, particularly elk and deer. Some 

of the studies are contradictory. Rost and Bailey (1979) reported that elk and mule deer avoided roads 

within a 200 meter distance. Thomas et al. (1979) indicated that roads open to vehicular traffic will 

adversely affect the use of an area by elk and, to a lesser extent, by deer.

Alteration of Terrestrial and Aquatic Wildlife Habitat

Forest roads and trails change the biological and physical conditions on and adjacent to them, creating 

edge effects with influences beyond the extent of the road prism (Trombulak and Frissell 2000). 

Trombulak and Frissell (2000) describe eight physical characteristics that are altered by roads: soil 

density, temperature, soil water content, light, dust, surface-water flow, pattern of run-off, and 

sedimentation.
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Long term use of roads causes soil compaction that lasts long after road use is discontinued. Increases 

in soil density on decommissioned roads can persist for decades.

Potential Effects of Habitat Alteration to Aquatic Species Habitats: Trombulak and Frissell 

(2000) report that surface temperature of a road increases as water vapor transport decreases. Heat stored 

on the road surface is released in the atmosphere at night, creating heat islands around roads. Small birds 

and snakes are attracted to warm roads and increase their risk of mortality from vehicle collision.

Road crossings may fragment stream habitat by acting as barriers to movement of fish and 

amphibians. Long term barriers can prohibit migration and create isolation in aquatic species, and 

ultimately reduce distribution and productivity of a population. Stream crossings may also degrade stream 

and riparian habitat depending on the location of the crossing and the type of substrate.

Roads can change the hydrology of slopes and stream channel characteristics which result in changes 

to surface-water habitats that may be detrimental to aquatic dependent species. Roads in floodplains may 

redirect water, sediment and nutrients, causing degradation to wetland and riparian habitats. Roads may 

alter surface or subsurface flow and can destroy and create wetland habitats. Erosion through channel 

down cutting, gully formation or head cuts may result when high concentration of runoff on hillslopes is 

caused by changes in routing of shallow groundwater and surface flow. These processes can be 

detrimental to aquatic species far downstream for a long period of time. In addition, chronic effects from 

fine sediment transported from unpaved roads to streams, lakes, and wetlands, increases turbidity, 

reducing productivity and survival or growth of fishes.

Bury (1980) reported that motorized vehicles crossing creeks pose some risk of gas and oil leaks into 

the creek. Oil and gas have been shown to have negative effects to the growth and survival in several frog 

species (Pollet and Bendell-Young 2000; Irwin et al. 1999, Lefcorte et al. 1997).

Potential Effects of Habitat Alteration to Terrestrial Wildlife Habitats: Forest roads and trails can 

both enhance and decrease habitat for wildlife (Jalkotzy et al. 1997). The road or trail creates edge habitat 

for species that are habitat generalists, particularly for some mammal species (e.g., coyote and deer mice) 

and some songbird species. Ravens are more common along roads since carrion is more available along 

these corridors. For habitat specialists, such as interior dwelling species that require intact, undisturbed 

patches of habitat such as the American marten and the spotted owl, roads can fragment habitat. Roads 

and trails can also fragment or disrupt habitat indirectly by introducing exotic or noxious weeds. In 

addition roads can increase pollutants like dust and vehicle emissions that can contaminate roadside 

vegetation which wildlife feed upon.

Increased Alteration and Use of Habitats by Humans

Several studies have indicated that high road densities result in adverse impacts on certain wildlife 

species. Impacts from high densities include excessive harvest including legal and illegal, 

disturbance/harassment from noise, and habitat alteration. Brocke et al. (1988) reported that high road 

densities can elicit a variety of negative impacts of certain wildlife species. These effects include human 

disturbance. In Adirondack counties, the black bear population density index (based on the number of 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

158 – Tahoe National Forest

legal kill) showed a ten-fold decrease when road density increased by ten times. Other studies were cited 

as showing similar sensitivity to road density for other large predators and ungulates.

Wildlife Effects Analysis Methodology

The Tahoe National Forest (NF) is one of ten national forests within the Sierra Nevada bioregion. The 

varied landscapes of the Sierra Nevada support a rich diversity of plant and animal species, some of 

which are found only in the Sierra Nevada. Species vary greatly in abundance and distribution, from very 

abundant and widespread to extremely rare and locally distributed, and all combinations in between. More 

than 550 vertebrate species have been identified in the Sierra Nevada bioregion, including approximately 

30 amphibian, 35 reptile, 130 mammal, 270 bird, and 95 fish species (SNFPA 2001, Appendix R).

This assessment consists of 4 steps: (1) identify wildlife species (and species groups) that allow for an 

informed analysis of alternative effects; (2) identify road and trail associated factors for each group; (3) 

develop and apply assessment processes and GIS models to evaluate the influence of road and trail 

associated factors on each group; and (4) analyze the effects of the proposed alternatives based on the 

model outputs and analyses.

Step 1. Identify wildlife species and groups

Existing information and knowledge about the distribution of the terrestrial and aquatic species on the 

Tahoe NF were used to develop the list of species and to develop species groups. Federally listed species, 

Forest Service Sensitive Species, Management Indicator Species, and other species were selected and 

placed into species groups based on the potential for these species or their habitats to be affected by 

motorized vehicle use on the Tahoe NF. Local knowledge and sources included corporate databases 

including distribution of special status species, vegetation maps, etc., which were used to develop species 

or habitat groups. Table 3.03-1 provides a list of all the special status species described by status, habitat 

indicator, and distribution on the Tahoe NF.

Table 3.03-1. List of Tahoe NF Special Status Species by Habitat Indicator and Distribution1

Species Federally 

Listed 

Forest 

Service 

Sensitive

Management 

Indicator 

Species

Other 

Species of 

Concern

Indicator Habitat or 

Ecosystem Component

Distribution on 

Tahoe NF

American 

Marten

X X Late-seral closed canopy 

coniferous forests

Forest-wide

Aquatic macro -

invertebrates

X Riverine and lacustrine habitats Forest-wide

Bald Eagle X Mature conifer forest near 

large bodies of water

Nests near or 

adjacent to specific 

reservoirs on 

theTahoe NF 

Band-tailed 

Pigeon

X Oak-associated Hardwood 

and Hardwood/conifer

Forest-wide

Black Bear X Early- and late-seral stages 

within all forest types

Forest-wide

Sooty (Blue) 

Grouse

X Late-seral open canopy 

coniferous forests

Forest-wide
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Tahoe National Forest – 159

Species Federally 

Listed 

Forest 

Service 

Sensitive

Management 

Indicator 

Species

Other 

Species of 

Concern

Indicator Habitat or 

Ecosystem Component

Distribution on 

Tahoe NF

California 

Floater

(mollusk)

X In fairly large streams and 

lakes, in relatively slow 

currents on soft substrates 

(mud-sand)

Not known to 

occur on the TNF, 

historically 

documented in 

Donner Lake

adjacent to the 

Tahoe NF.

California Redlegged Frog

X Cold water ponds and stream 

pools with depths exceeding 

0.7 meters and with 

overhanging vegetation such 

as willows, as well as 

emergent and submergent 

vegetation

Suitable habitat on 

west side of TNF 

below 4,000 ft;. no 

known occupied 

habitat on TNF; 3 

known populations 

on private land 

adjacent to TNF.

California 

Spotted Owl

X X Mature and late-seral closed 

canopy coniferous forest 

(ponderosa pine, Sierran 

mixed conifer, white fir, red 

fir), tree size 4 & 5 (canopy 

closures M and D), and tree 

size 6

Forest-wide

California 

Wolverine

X Various habitat types used, 

coniferous forests, subalpine 

and alpine areas above 8,000 

ft.

Verified detections 

on the eastside of 

the Tahoe NF. 

Coniferous 

forest birds

X Coniferous forests, all seral 

stages, all canopy closures

Forest-wide

Foothill 

Yellow-legged 

Frog

X Shallow, slow flowing water of 

rocky streams and rivers in a 

variety of habitats including 

riparian, mixed conifer, and 

wet meadow types below 

6000 feet elevation on the 

west slope of the Sierra 

Nevada

Below 6000 feet 

elevation on the 

west slope of the 

Tahoe NF

Fox Sparrow X Shrubland (west-slope 

chapparral types)

Westside of the 

Tahoe NF on the 

Yuba River 

Ranger District 

and American 

River Ranger 

District.

Great Gray 

Owl

X Mature and late-seral conifer 

forest adjacent to meadows

One recent 

confirmed sighting 

on TNF, but 

breeding has not 

been verified. 

Recent sightings 

on private land.

Greater 

Sandhill Crane

X Wet meadow, shallow 

lacustrine, and fresh 

emergent wetland habitat 

Only known 

breeding at 

Kyburz Flat and 

Carman Valley on 

Sierraville RD 

Reported on pvt 

land in Sardine 

Valley.
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160 – Tahoe National Forest

Species Federally 

Listed 

Forest 

Service 

Sensitive

Management 

Indicator 

Species

Other 

Species of 

Concern

Indicator Habitat or 

Ecosystem Component

Distribution on 

Tahoe NF

Great Basin 

Ramshorn 

Snail

X Lakes and larger, slow 

streams in and around the 

northern Great Basin; suitable 

habitat on TNF within slow 

segments of the Truckee and 

Little Truckee Rivers and 

tributaries

No verified 

locations on TNF; 

historically found 

in the Truckee 

River downstream 

of Lake Tahoe, on 

the LTBMU 

Hairy 

Woodpecker

X Medium and large snags in 

green forest

Forest-wide

Hardhead (fish) X Great Valley and Foothill 

belts, and in larger west-slope 

streams into the Yellow pine 

belt

No verified 

locations on TNF; 

historic report on 

Sierraville RD 

Lahontan 

Cutthroat 

Trout

X Historically and currently 

occupied streams and lakes

Limited distribution 

on Sierraville and 

Truckee ranger 

districts 

Lahontan Lake 

Tui Chub (Fish)

X Lakes and reservoirs, known 

only from Pyramid Lake and 

Lake Tahoe.

Possible 

population in 

Stampede, Boca 

and Prosser 

Reservoirs on the 

Tahoe National 

Forest.

Mountain 

Quail

X Early- and mid-seral 

coniferous forest (ponderosa 

pine, Sierran mixed conifer, 

white fir, red fir, eastside pine, 

tree sizes 1, 2, and 3, all 

canlopy closures

Forest-wide

Mountain 

Yellow-legged 

Frog

X Low gradient (up to 4%) 

perennial streams and lakes 

above 4500 feet elevation

Locations above 

4,500 ft. on the 

TNF, has 

disappeared from 

many historic 

locations on the 

Tahoe NF

Mule Deer X Uses a variety of habitats 

Forest-wide including mid, 

early, and late-seral forests; 

meadows; riparian areas; and 

shrublands

MIS indicator habitat - Oakassociated Hardwood & 

Hardwood/conifer

Indicator habitat 

occurs on the 

westside of the 

Tahoe NF. Deer 

populations occur 

forest-wide.

Northern 

Flying Squirrel

X Late-seral closed canopy 

coniferous forest (ponderosa 

pine, Sierran mixed conifer, 

white fir, red fir), tree size 5 

(canopy closures M and D), 

and tree size 6

Forest-wide

Northern 

Goshawk

X Mature and late-seral

moderate to closed canopy, 

coniferous forest (ponderosa 

pine, Sierran mixed conifer, 

white fir, red fir, east side 

pine, and lodgepole), tree size 

4 & 5 (canopy closures M and 

D), and tree size 6

Forest-wide
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 161

Species Federally 

Listed 

Forest 

Service 

Sensitive

Management 

Indicator 

Species

Other 

Species of 

Concern

Indicator Habitat or 

Ecosystem Component

Distribution on 

Tahoe NF

Northwestern 

Pond Turtle

X Ponds, marshes, rivers, and 

streams with rocky or muddy 

bottom and aquatic 

vegetation/ nest sites consist 

of sandy to very hard soil 

types, and can be as much as 

325 feet from water (Zeiner et 

al. 1988)

Yuba River 

drainage

Pacific Fisher

(mammal)

X Mature and Late-seral closed 

canopy coniferous forest 

(ponderosa pine, Sierran 

mixed conifer, white fir, red 

fir), tree size 4 & 5 (canopy 

closures M and D), and tree 

size 6

Suitable habitat 

only, Tahoe NF 

falls within 

identified fisher 

distribution gap

Pacific Tree

Frog

X Wet Meadow Forest-wide

Pallid Bat X Affinity for oak and mixed 

hardwood conifer, Roost sites 

can include buildings, mines, 

caves, and live oak trees and 

oak snags.

Primarily below 

6,000 feet. 

Documented at 

SVRD at Carman 

Valley.

Sierra Nevada 

Red Fox

X Mature subalpine conifer 

forest and riparian/montane 

meadow

Suitable habitat, 

no known or 

verified detections

Western Gray 

Squirrel

X Oak hardwood and mixed 

oak/conifer forest

Strongly tied to 

wesdie oak and 

oak/conifer forests

Western Red 

Bat

X Riparian habitat and 

hardwoods within riparian 

areas; roosts within tree 

foliage or shrubs, and often 

along edge habitat adjacent to 

streams or open fields 

(Bolster 1998)

Habitat is 

generally below 

3,000 feet, 

however detected 

at Carman Valley 

on the Sierraville 

RD at 6,000 ft

Wild Turkey X Oak hardwood and mixed 

oak/conifer forest

Primairly westside 

of Tahoe NF in 

suitable habitat

Willow 

Flycatcher 

X Riparian shrub (willow) and 

wet meadow

Occurs at discreet 

willow/meadow 

habitat on SVRD, 

TKRD, and YRRD. 

Yellow Warbler X Riparian Forest-wide

1 Valley elderberry longhorn beetle is not included since their habitat is not on the Tahoe NF and are not affected by this project.

The species assessment presented here is organized by Species Groups divided along major habitat 

associations (for example, riparian habitat) or life zones (for example, terrestrial or aquatic). Projected 

effects of motorized vehicle travel management on sets of species in these major groupings are described. 

In addition, individual species assessments are presented for federally listed species, Forest Service 

Sensitive Species, and Management Indicator Species, and other species of concern. More detailed 

information is also found in the Biological Evaluation and Project-Level Management Indicator Species 

project report, and Tahoe NF Management Indicator Species report, which are incorporated by reference.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

162 – Tahoe National Forest

The species group assessment considers 36 species, including the special status species listed in Table 

3.03-2. These include aquatic macroinvertebrates, 5 amphibian species, 2 aquatic invertebrate species, 3 

fish species, 1 reptile species, 15 bird species, and 9 mammal species. These species were divided into 

species groups (some species occurred in more than one group) as described in Table 3.03-2.

Species not included in these assessments include the Valley elderberry longhorn beetle since their 

habitat is not on the Tahoe NF. Assessment for the Valley elderberry longhorn beetle is in the Biological 

Evaluation and incorporated by reference.

Table 3.03-2. Species group and species represented within groups

Species group Species

Wide-ranging carnivores Black bear, wolverine, Sierra Nevada red fox

Ungulates Mule deer

Oak and oak-conifer associated species Band-tailed pigeon, mule deer, pallid bat, wild turkey, western 

gray squirrel

Shrubland (west-slope chaparral) associated species Fox sparrow

Early- and mid-seral coniferous forest associated species Mountain quail

Late-seral open canopied coniferous forest Sooty (blue) grouse

Old forest conifer (late-seral) associated species California spotted owl, northern goshawk, great gray owl, 

American marten, Pacific fisher, northern flying squirrel, forest 

coniferous birds (e.g., brown creeper)

Snag associated species Hairy woodpecker, pallid bat

Aquatic and riparian associated species [including lacustrine 

(lakes) and riverine habitat (rivers, streams)]

Bald eagle, great gray owl, greater sandhill crane, willow 

flycatcher, yellow warbler, aquatic macroinvertebrates, California 

floater, Great Basin ramshorn snail, Lahontan cutthroat trout, 

Lahontan tui chub, hardhead, California red-legged frog, foothill 

yellow-legged frog, mountain yellow-legged frog, Pacific tree frog, 

northwestern pond turtle, Sierra Nevada red fox, Western red bat. 

Step 2. Identify road and trail-associated factors

Several studies have identified a classification or conceptual model of responses of wildlife to road and 

trail-associated activities (Knight and Cole, and Liddle in Gaines, et al. 2003). The causal factors were 

grouped by impact to wildlife into habitat alteration, mortality (including legal harvesting), and 

disturbance. (1) Habitat alteration occurs when habitat is modified through creation of a path, presence 

of food, or removal of vegetation. (2) Mortality is human-induced where there is a direct and negative 

impact on the animal such as hunting, fishing, poaching or illegal take, collision with vehicles, and other 

incidental contact which results in impacts similar to those from hunting. (3) Disturbance is when an 

animal sees, hears, smells, or otherwise perceives the presence of a human but no contact is made and it 

may or may not alter its behavior.

Based on a review of literature and local knowledge of selected species on the Tahoe NF, these three 

broad response classifications were used for this assessment. Refer to Table 3.03-3.
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Table 3.03-3 lists the road and trail-associated response classifications, response factors and definitions, and affected species groups

Response Classification2 Road and trail –

associated factors1 Definition of response factors Species group affected

Habitat alteration Habitat loss and 

fragmentation

Loss and resulting fragmentation of habitat due to the 

establishment of roads, trails, or networks, and 

associated human activities

• Wide-ranging carnivores

• Ungulates

• Old forest coniferous species

• Early- and mid-seral coniferous pecies

• Aquatic-Riparian species 

Edge effects Changes to habitat microclimate associated with the 

edge induced by roads or trails

• Old forest conifer species

Snag or downed log 

reduction

Reduction in density of snags and down logs due to 

their removal near roads as facilitated by road access 

(e.g., fuelwood gathering)

• Wide-ranging carnivores

• Old forest coniferous species

• Snag dependent species

Route for competitors and 

predators

A physical human-induced change in the environment 

that provides access for competitors or predators that 

would not have existed otherwise

• Wide-ranging species

• Ungulates

• Old forest coniferous species

• Early- and mid-seral species

• Aquatic-Riparian associated

• Oak-Associated hardwood & 

hardwood/conifer species

• Snag-dependent species

• Shrubland associated species

Mortality Hunting and trapping (legal 

harvest)

Mortality from hunting or trapping as facilitated by road 

and trail access

• Wide-ranging carnivores

• Ungulates

• Oak Associated Species

• Early- and mid-seral coniferous forest

Poaching Increased illegal take of animals as facilitated by trails 

and roads

• Wide-ranging carnivores

• Ungulates

• Oak Associated species

• Early- and mid-seral coniferous forest

Collisions Mortality or injury resulting from a motorized vehicle 

running over or colliding with an animal

• Wide-ranging carnivores

• Ungulates

• Old forest coniferous species

• Aquatic-Riparian species

Collection Collection of live animals for use as pets (such as 

amphibians and reptiles) as facilitated by the physical 

characteristics of roads or trails or by road or trail 

access

• Old forest coniferous species

• Aquatic-Riparian species 
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164 – Tahoe National Forest

Response Classification2 Road and trail –

associated factors1 Definition of response factors Species group affected

Disturbance Disturbance at a specific 

site

Displacement of individual animals from a specific 

location (e.g., such as a site that is being used for 

reproduction and rearing of young)

• Wide-ranging carnivores

• Ungulates

• Old forest coniferous species

• Early- and mid-seral species

• Aquatic-Riparian associated

• Oak-associated hardwood & 

hardwood/conifer species

• Snag-dependent species

• Shrubland associated species

Physiological response Increase in heart rate or stress hormones when near a 

road or trail or network of roads or trails leading to a 

potential loss of fitness

• Wide-ranging carnivores

• Ungulates

• Old forest coniferous species

• Early- and mid-seral species

• Aquatic-Riparian associated

• Oak-Associated hardwood & 

hardwood/conifer species

• Snag-dependent species

• Shrubland associated species

1 Based in part on Wisdom et al. 2000 In: Gaines et al. 2003

2 Disturbance occurs when an animal sees, hears, smells, or otherwise perceives the presence of a human but no contact is made and it may or may not alter its behavior.

Habitat modification is when habitat is changed in some way. Mortality involves human actions in which there is direct and damaging contact with the animal.
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Tahoe National Forest – 165

Step 3. Processes and models

The assessment process to analyze the effects of motorized travel routes (road and trails) on the Tahoe NF 

was done in three general steps: (1) Road density was derived within specific wildlife habitats, (2) the 

effects of travel routes to species groups were assessed based on a similar process completed by Gaines et 

al. 2003, and (3) the relative environmental risk of roads and trails to habitats was determined. Gaines et 

al. (2003) used an assessment process that utilizes focal species and groups and GIS models to evaluate 

road and trail associated influences to species and their habitats.

Step 4. Analysis of effects

The information generated in step 3 was used to analyze the direct, indirect and cumulative effects of the 

proposed alternatives on wildlife species and groups. Three primary indicators were used to compare and 

measure project effects of each alternative: density of motorized routes, miles of routes, and Zone of 

Influence of motorized routes. In addition, for species, such as spotted owls, goshawk, and bald eagles, 

for which disturbance from motorized use has the potential to effect reproductive status, disturbance to a 

specific site was analyzed. These measures, described in the next section, are used for relative 

comparisons of the alternatives. The analysis indicators are focused on assessing the effects of

1) Prohibiting cross country travel, 2) Additions (user created roads/trails and temporary roads) to 

the NFTS, 3) Establishment of Motorized “Open Areas,” 4) Changes to the NFTS including, change 

in class of vehicles, and change in season of use, and reopening Maintenance Level 1 roads to motorized 

use, and 5) Amendments to the Forest Plan.

Description of Indicators Used to Measure Effects of the Alternatives

Indicators used to measure effects are presented in the environmental consequences section to compare 

and contrast the effects of the action alternatives. Measures were selected for project effects based on a 

thorough review of literature on the interaction between wildlife and motorized routes. Because there are 

limited data and studies for many species, assumptions and generalizations were made for some species 

where no data were available. Generally, the risk factors described in the section above (habitat alteration, 

mortality, and disturbance, Table 3.03-3) were considered as well as other factors known to be important. 

Three primary indicators were used to compare and measure project effects of each alternative: 

density of motorized routes, miles of routes, and Zone of Influence of motorized routes. 1) Density of 

motorized routes has often been used as a surrogate to estimate habitat effectiveness or the direct, 

indirect, and cumulative effects of motorized routes on terrestrial wildlife habitat. The density of 

motorized routes provides a way to assess the cumulative impact of motorized routes for the alternatives.

2) Miles of motorized routes are used to measure disturbance potential to aquatic and terrestrial wildlife 

species and their habitats. 3) The Zone of Influence is the portion of a species (or species group’s) key 

habitat that is influenced by motorized routes from disturbance, mortality risk or habitat alteration. These 

measures are used for relative comparisons of the alternatives. Additional analysis measures were 

required for a few species, especially if directed by policy or regulation; for example, some species 

require analysis of disturbance at a specific site.
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166 – Tahoe National Forest

Density of Motorized Routes: Route density thresholds for wildlife have not been established on the 

Tahoe NF, and thresholds for wildlife in the literature can vary by season and by geographic location. 

Therefore, route density “thresholds” will not be used to determine effects of the action alternatives, but 

rather route density is used for a relative comparison of the alternatives. Route density was determined at 

the scale of 7th field watershed, since this scale is sufficiently large to accurately estimate road densities. 

Route densities at a larger scale could potentially mask route density effects and therefore, underestimate 

effects to wildlife species. Route densities at any smaller scale may actually be amplified and therefore 

overestimate the effects to wildlife. Route density calculations for Alternative 1 include existing 

unauthorized routes because use of these routes can be assumed to continue as part of continued cross 

country travel. Route density includes all motorized routes, including existing NFTS system, non-NFS 

routes, etc. because route density must be calculated across an area (miles per square mile), and therefore 

serves as a cumulative effects analysis. For the preparation of the DEIS, motorized route densities were 

prepared for several species as well as a generalized analysis not specific to any species; all of these 

analyses determined that the relative relationships remained the same regardless of species, thus the 

generalized table is shown under the section Summary of Effects Common to All Species in Table 3.03-4.

Miles of Motorized Routes: Use of motorized routes has the potential to affect wildlife in a number 

of ways, such as behavioral changes, increased stress or changes in reproductive success. 

Miles of motorized routes is used in addition to route density because many motorized routes are 

difficult to assess on the scale of the entire forest. Overall miles of motorized routes on the Tahoe NF are 

used to compare differences in disturbance potential of motorized use among alternatives.

In addition to overall miles of motorized routes across the entire forest, it is important to analyze the 

disturbance potential at specific sites for some species. The number of miles of motorized routes within a 

particular distance to a species reproductive site can be used to determine the potential disturbance to 

wildlife species. The distance from a site used to analyze disturbance potential varies by each species’ 

disturbance threshold based upon literature review. Species-specific disturbance potential of motorized 

routes was compared for California spotted owl and the northern goshawk reproductive sites (nests or 

activity centers). In addition, the number of miles of motorized routes occurring within spotted owl 

Protected Activity Centers (PACs) and Home Range Core Areas (HRCAs) and goshawk Protected 

Activity Centers (PACs) were also compared by alternative.

Zone of Influence: Motorized routes have a Zone of Influence within which habitat effectiveness or 

suitability is reduced and wildlife population densities are lower (Trombulak and Frissell 2000, Gaines, et 

al. 2003). The effects to wildlife extend beyond the immediate road prism itself, into what can be referred 

to as a Zone of Influence adjacent to motorized roads and trails. The degree of effect of the various factors 

associated with roads and trails can be evaluated more effectively when considering the proportion of a 

given species habitat that occurs within this Zone of Influence of motorized routes. Wildlife species 

behaviors and habitats are modified within various distances from motorized routes. The distances of the 

Zone of Influence for individual species that are used in the analysis of effects are based upon the best 

available science in the literature. The Zone of Influence is a relative index of habitat effectiveness to 

compare alternatives.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 167

For several species or species groups, several Zones of Influence were analyzed and the results 

presented in the DEIS. The results of these analyses indicated that insignificant differences were present 

among the scales (usually 60, 100 and 200 m). Any effects shown to be present at the smaller scales were 

contained at the largest scale, and the results gained from the smaller scales do not substantially inform 

the decision. Thus, in this document, the analysis reports only the largest Zone of Influence.

Assumptions for Wildlife Effects Analysis

1. All vehicle types result in approximately the same amount of disturbance effect to wildlife.

2. Disturbance effects were considered to be equal in all seasons because of the difficulty in parsing 

out effects for each season. Where seasonal ranges are identified, such as for mule deer, or for 

breeding habitat, this inherently considers a seasonal aspect.

3. Location of route is equal to disturbance effects from that route (e.g., assume all trails provide 

the same level of disturbance).

4. Habitat is already impacted in the short-term. In the long-term, habitat will remain the same on 

motorized routes added to the NFTS, but impacts will decrease to at least some degree on nonadded trails with the prohibition of cross country motorized travel and subsequent passive 

restoration (see Soils section for further assumptions).

5. The focus of this analysis is on suitable habitat; suitable habitat is assumed occupied unless it has 

been surveyed to a standard that determines absence.

6. Noise generated from non-motorized associated disturbance impacts are limited to within 60 

meters of motorized roads and trails.

7. The cumulative effects of past projects are incorporated within the existing vegetation and travel 

system maps.

8. Route densities for the action alternatives are calculated based on existing motorized system 

routes, private land routes, and proposed motorized route additions to the NFTS. The estimation 

of route densities for Alternative 1 (no action) includes all existing unauthorized routes, as well 

as existing motorized system routes, private land routes, and proposed route additions to the 

NFTS. It is assumed that unauthorized routes would continue to be used under continued cross 

country travel. 

9. Continued cross country motorized travel under the No Action Alternative (Alternative 1) will 

lead to continued proliferation of motorized routes, which would have a high likelihood of 

increasing over time (see Chapter 3.07, Recreation and Scenic Values).

10. Although the type and amount of use along the different types of routes may result in different 

effects to wildlife species, all motorized routes are treated equally in this analysis because the 

relationship between effects and motorized route type and intensity of use is complex and not 

well understood. For example, the type of motorized road or trail likely varies in how roads and 

motorized trails contribute to disturbance and habitat fragmentation: high clearance roads 

generally receive less use than roads used by passenger vehicles, which would equate to less 

noise disturbance, and single track motorcycle trails would likely fragment habitat less than 
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168 – Tahoe National Forest

would a passenger road due to the narrower width of the single track motorcycle routes that 

would result in removing less habitat. However, noise generated from motorcycles along trails 

may contribute to greater noise disturbance than would a 4x4 jeep. Since impacts to the wildlife 

species analyzed here are not well understood, impacts from all motorized routes, regardless of 

motorized route type and intensity of use, are treated the same.

Sources of Information for Wildlife Effects Analysis

GIS layers of the following wildlife resources were used for analysis:

• Bald Eagle – nest sites

• California Spotted Owl – nest sites, Activity Centers, Protected Activity Centers, Home Range 

Core Areas, CWHR habitat types 4M, 4D, 5M, 5D, and 6

• Northern Goshawk – nest sites, Protected Activity Centers, CWHR habitat types 4M, 4D, 5M, 5D, 

and 6

• Mule Deer – key deer habitat areas including winter, critical winter, fawning, and critical summer 

ranges. In addition, oak woodland and oak-conifer woodland habitats were used, since mule deer 

is a Management Indicator Species for oak and oak-conifer woodland habitats. 

• Forest Carnivores (marten, fisher, Sierra Nevada red fox, and wolverine) – Tahoe Forest Carnivore 

Network, CWHR habitat types 4M, 4D, 5M, 5D, and 6)

• Snag analysis – 60 meters buffered on routes in forested habitats.

Affected Environment and Environmental Consequences

by Species Groups

This section describes both the affected environment and environmental consequences of the alternatives 

arranged by species groups: wide-ranging carnivores, ungulates, oak and oak-conifer forests, shrubland, 

early- and mid-seral coniferous forest, late-seral open canopied coniferous forest, old coniferous forest, 

snag, and aquatic and riparian associated species. Selected species represented within each group include 

Threatened, Endangered, Sensitive, and Proposed (TESP) species, MIS, or other species of concern (such 

as, snag dependent species and forest coniferous birds) are included. While not all the species within the 

groups are necessarily analyzed in detail, each species group analysis provides enough information to 

infer impacts. 

Affected Environment Description

The Affected Environment discussion focuses on pertinent literature available for selected species within 

the wildlife groups and does not represent an exhaustive or comprehensive literature summary on wildlife 

and road interactions. For some species represented in the group, little information may be available on 

wildlife interaction with roads and trails. Known information on the distribution and status of the species 

on the Tahoe NF is also presented in the affected environment section for each selected species, 

particularly species with special status (threatened, endangered, sensitive or management indicators 

species).
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Environmental Consequences Description

Direct and Indirect Effects Boundary: Direct and indirect effects of each alternative are analyzed on 

NFS lands within the boundary of the Tahoe National Forest. The analysis area includes motorized roads 

and trails, collectively referred to as routes. Routes include existing system routes and motorized trails to 

the NFTS. 

Cumulative Effects Boundary: Cumulative effects are bounded spatially and temporally. The 

geographic boundary for analyzing cumulative effects are lands that fall within the boundary of the Tahoe 

NF, including all NFS lands and non-NFS lands (private). This habitat type encompasses 821,035 acres of 

NFS lands and 373,359 acres of non NFS lands. This cumulative effects geographic boundary pertains to 

all species groups except for greater sandhill cranes and the oak and oak-conifer group. For sandhill 

cranes, the cumulative effects boundary is known sandhill crane breeding habitat at Sardine Valley, 

Carman Valley, and at Kyburz Flat on the Sierraville and Truckee Ranger Districts. 

The cumulative effects boundary for the oak and oak-conifer species group (65,329 acres) falls within 

the Yuba River and the American River ranger districts within pure oak woodland and oak-conifer habitat 

on the west side of the Tahoe NF.

An appropriate scale to analyze cumulative effects of terrestrial and aquatic species for activities 

associated with motorized roads and trails requires an area sufficiently large to encompass wildlife 

habitat, movement patterns, and home ranges for the groups of species being analyzed within the project 

area including old forest associated species, wide-ranging species, riparian associated species and others; 

such an appropriate scale includes all lands within the boundary of the Tahoe NF. 

Within the cumulative effects boundary, cumulative effects from motorized routes are analyzed 

quantitatively using route density by assessing the accumulation of all past, present, and future routeassociated actions, including existing system routes, motorized routes added to the NFTS, and any future 

routes that would be created within the next 20 years within the boundary of the Tahoe NF (NFS and nonNFS lands). In addition, overall cumulative effects from other past, present, and reasonably foreseeable 

future actions are described. Twenty years is a reasonable timeframe for estimating cumulative impacts of 

motorized routes in the reasonably foreseeable future. Past actions include routes that were created within 

the last 50 to 100 years and will be incorporated into the existing condition, such as closed or 

decommissioned roads. 

In order to understand the contribution of past actions to the cumulative effects of the Proposed 

Action and alternatives, this analysis relies on current environmental conditions as a proxy for the impacts 

of past actions. This is because existing conditions reflect the aggregate impact of all prior human actions 

and natural events that have affected the environment and might contribute to cumulative effects.

This cumulative effects analysis does not attempt to quantify the effects of past human actions by 

adding up all prior actions on an action-by-action basis. There are several reasons for not taking this 

approach. First, a catalog and analysis of all past actions would be impractical to compile and unduly 

costly to obtain. Current conditions have been impacted by innumerable actions over the last century (and 

beyond), and trying to isolate the individual actions that continue to have residual impacts would be 

nearly impossible. Second, providing the details of past actions on an individual basis would not be useful 
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170 – Tahoe National Forest

to predict the cumulative effects of the Proposed Action or alternatives. In fact, focusing on individual 

actions would be less accurate than looking at existing conditions, because there is limited information on 

the environmental impacts of individual past actions, and one cannot reasonably identify each and every 

action over the last century that has contributed to current conditions. Additionally, focusing on the 

impacts of past human actions may risk ignoring the important residual effects of past natural events 

which may contribute to cumulative effects just as much as human actions. By looking at current 

conditions, we are sure to capture all the residual effects of past human actions and natural events, 

regardless of which particular action or events contributed to those effects. Finally the Council on 

Environmental Quality issued an interpretive memorandum on June 34, 2005 regarding analysis of past 

actions, which states, “agencies can conduct an adequate aggregate effects of past actions without delving 

into the historical details of individual past actions.” For these reasons, the analysis of past actions in this 

section is based on current environmental conditions and is represented in the current maps used to 

analyze cumulative effects that have occurred in the past 100 years or more.

In addition, Past actions for the previous 20 years will be discussed under each species as appropriate, 

including activities as timber harvest, grazing, and non-motorized recreation that provides pertinent 

information of relatively recent activities that may still be impacting species and their habitats. 

Overall Relative Cumulative Impact Scores: As a relative measure of the negative and positive 

effects from motorized routes under each of the alternatives, a simple sum total of the percentages of 

some metrics were calculated. Some overlap of percentages may occur where route categories intersect, 

however, because it is a relative and not absolute score, the relationships remain valid. The metric is 

intended to provide only a relative measure of effects and does not include all impacts.

Summary of Effects Analysis for All Species and Species Groups

The following effects analysis reflects many detailed conclusions of the effects of the alternatives. This 

paragraph broadly generalizes the conclusions from all species and species groups. Alternative 1, the 

existing condition, is by far the most adverse condition for all species and species groups on the Tahoe NF 

due primarily to the disturbance, habitat alteration and potential mortality associated with unlimited cross 

country travel, including continued travel on unauthorized routes (user created and temporary roads) and 

motorized travel in areas where there are currently no unauthorized routes leading to the creation of 

additional routes. Most wildlife species are adversely affected by human disturbance to varying degrees, 

and the growth of unlimited cross country travel associated with an expanding human population and 

growing recreational use of public lands would continue to cause adverse effects into the future. This 

adverse effect is so great that all of the action alternatives in comparison are greatly beneficial to more or 

less degree. 

All action alternatives have varying effects to each of the species and species groups, and are 

described in detail in the sections that follow. Due to the magnitude of the beneficial effect of controlling 

adverse impacts such as existing cross country use, all the action alternatives appear to have similar 

benefits to wildlife. However, when only the action alternatives are compared at a similar scale, the 

impacts among the alternatives are more apparent and indicate that Alternative 5 has the greatest potential 
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Tahoe National Forest – 171

to negatively impact wildlife than the other action alternatives. Alternative 5 negatively impacts the most 

wildlife species and the most wildlife groups of the action alternatives. The species and groups most 

adversely affected by the existing condition are wide-ranging carnivores, mule deer, spotted owls and 

northern goshawks because these groups are especially affected by disturbance. Alternative 5 has the 

greatest negative impacts to these same groups, followed by Alternatives 2, 6, 7, 4, and 3 in descending 

order. In general, aquatic and riparian associated wildlife species are benefited by Alternatives 4, 5, and 6 

which implement wet weather seasonal restrictions and would reduce the potential for sedimentation off 

of native-surfaced motorized routes into aquatic and riparian ecosystems.

Summary of Effects Common to All Species

Wet Weather Seasonal Closures: Wet weather restrictions generally would not affect terrestrial wildlife 

habitats. However, there is some potential for direct disturbance to terrestrial species from motorized use 

during the wet weather season. Wet weather restrictions would reduce disturbance to terrestrial species 

when wet weather restrictions are implemented. In addition, terrestrial wildlife species using riparian and 

aquatic habitats would benefit from proposed wet weather seasonal restrictions on native surfaced roads 

and trails. The effects of the alternatives on terrestrial wildlife species that use riparian and aquatic 

habitats are disclosed under the aquatic and riparian associated species section. Motorized travel on native 

surfaced routes during the wet weather season has the potential to cause erosion and deliver sediment to 

aquatic and riparian species and their habitats.

Alternatives 4, 5, and 6 would impose wet weather seasonal restrictions on all native surfaced roads 

and motorized trails. Riparian and aquatic dependent species would be benefited through the reduction of 

erosion and sedimentation that could occur from wet season wheeled motorized use on routes, especially 

motorized roads and trails that are within close proximity to, or cross, streams or other riparian aquatic 

habitats. Alternatives 1, 2, 3, and 7 do not impose wet weather seasonal restrictions on native surfaced 

motorized routes and therefore, aquatic and riparian dependent species would not benefit from wet 

weather seasonal restrictions. Alternative 1 has the greatest number of motorized stream crossings and 

highest Riparian Conservation Area (RCA) route densities. Alternative 1 has the highest potential to 

deliver sediment to aquatic and riparian habitats from wheeled motorized use on native surfaced routes

during the wet weather season.

Change in Class of Vehicles: Although responses to motorized vehicle use vary by species and 

depend upon the type of vehicle, in addition to the intensity, timing, speeds, and amount of motorized 

vehicle use, the specific species responses are not well understood. For these reasons, this analysis has 

assumed that all vehicle types result in the same disturbance to wildlife. 

Overall, the change is the class of vehicles would not likely have a measurable effect to habitat, since 

the change in class of vehicles on existing motorized routes will generally not affect or alter habitat 

condition. In general, some smoothed surfaced roads may become rough surfaced roads through changed 

road maintenance. In addition, some existing motorized NFTS roads may receive different maintenance 

resulting in higher vegetation density at the road margins which would provide additional cover and/or 
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172 – Tahoe National Forest

foraging habitat. The resulting roadway condition would depend upon the amount and type of vegetation 

present and the amount of maintenance any given road receives.

Therefore, changes in the class of vehicles would not vary in their effects to species or species groups 

for all the action alternatives. 

Density of motorized routes for habitat effectiveness: Route density has often been used as a 

surrogate to estimate habitat effectiveness or the direct and indirect effects of motorized routes on 

terrestrial wildlife. Route density thresholds for wildlife have not been established on the Tahoe NF, and 

thresholds for wildlife in the literature can vary by season and by geographic location. Therefore, road 

density “thresholds” will not be used to determine effects of the action alternatives, but rather road 

density is used for a relative comparison of the alternatives. Route density was determined at the scale of 

7th field watershed, since this scale is sufficiently large to accurately estimate road densities. Route 

densities at a larger scale could potentially mask route density effects and therefore, underestimate effects 

to wildlife species. Route densities at any smaller scale may actually be amplified and therefore 

overestimate the effects to wildlife. Route density calculations for Alternative 1 include existing 

unauthorized routes because use of these routes can be assumed to continue as part of cross country

travel. Route density includes all motorized routes, including existing NFTS system, non-NFS routes, etc. 

because route density must be calculated across an area (miles per square mile)

Table 3.03-4 provides a generalized overview of motorized route densities when looked as a measure 

of effects for all wildlife species for which route density is an issue. In the following sections, route 

densities are also calculated individually for species or species groups where helpful to determine effects.

Table 3.03-4. Generalized effects of motorized route densities (proportion of Tahoe NF acreage) between 0 

miles per square mile and greater than 6 miles per square mile (averaged by 7th field watershed)

Alternatives Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Motorized Route 

Density

(Percent of Forest 

Total)

0 Miles/Square Mile 0.6 0.6 0.6 0.6 0.6 0.6 0.6

0-2 Miles/Square Mile 17.2 26.6 27.7 26.6 25.0 27.2 26.6

2-4 Miles/Square Mile 44.0 57.7 56.6 57.7 58.2 57.0 57.7

4-6 Miles/Square Mile 31.4 11.5 11.9 11.5 12.6 11.5 11.5

>6 Miles/Square Mile 6.9 3.5 3.1 3.5 3.6 3.5 3.5

*Alternative 1 includes miles of user created and temporary routes that would remain with continued use

Establishment of Motorized “Open Areas”: One action alternative, Alternative 2, proposes open 

motorized areas at Greenhorn Area (60 acres) and access to 2,589 acres at the Boca, Stampede, and 

Prosser reservoirs on dry soils. Alternative 6 allows access to 244 acres at Boca, Stampede, and Prosser 

reservoirs on dry soils. The other action alternatives do not include this proposal so there would be no 

effect. For a few species, additional information is included in addition to the discussion below.

The Greenhorn area is located just outside of Nevada City. It is a popular four wheel drive and 

motorcycle use area by local residents. The majority of the area was hydraulically mined during the gold 

rush resulting in a lack of vegetation. The area also has a currently operating gravel plant. The Greenhorn 

area provides suitable habitat for very few species due to the amount of human activity and urban 
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Tahoe National Forest – 173

development in the area. Therefore implementation of Alternative 2 would not likely pose a concern for 

the species analyzed in this document. If individual animals are using the area, they could receive some 

localized, direct disturbance, but because the area is already receiving concentrated use by people, any 

animals using the area likely have adapted to the amount of use occurring or have already avoided the 

area.

As water levels are drawn down in Boca, Stampede, and Prosser reservoirs, motor vehicles are used 

to access the shoreline for recreational activities during the summer months (boating, camping, fishing 

and picnicking). They are typically not used as open play areas as is the Greenhorn Area. The three 

reservoirs occur on the Truckee Ranger District within eastside pine habitat. Minor and incidental direct 

impacts to animals traveling in vicinity of the reservoirs may occur. The area used to access the reservoirs 

has no vegetation, and therefore does not provide cover or forage habitat. Overall, access to the three 

reservoirs designated in Alternatives 2 and 6 would have no to minimal direct, indirect, or cumulative 

impact to species analyzed here. Cross country use of these “Open Areas” would continue under 

Alternative 1.

Wide-Ranging Carnivores Species Group: 

Affected Environment

Large and mid-sized carnivores are unique in their response to human-induced habitat changes due to 

their large spatial habitat needs and their sensitivity to landscape patterns, including road edge effects and 

road density (Buskirk and Zielinski 2003 In Zabel, et al 2003). The wolverine and the Sierra Nevada red 

fox may be considered to be sensitive to the presence of humans and human activities (Claar et al. 1999, 

Grinnell et al. 1937). Three species were included in the wide-ranging carnivore habitat assessment 

group: black bear (Ursus americana), the wolverine (Gulo gulo), and the Sierra Nevada red fox (Vulpes 

vulpes necator).

The following is a summary of some of the potential trail- and road-associated effects to wide 

ranging-carnivores (Gaines et al. 2003):

• Mortality from hunting or trapping as facilitated by road and trail access;

• Increased illegal poaching of animals as facilitated by trails and roads;

• Mortality or injury resulting from a motorized vehicle running over or hitting an animal;

• Displacement of individual animals from a specific location that is being used for reproduction 

and rearing of young;

• Change in behavior and/or increased mortality of animals (euthanasia or shooting) due to 

increased contact with humans, as facilitated by road and trail access including recreational sites, 

such as campgrounds;

• Interference with dispersal or other movements as posed by a road or trail itself or by human 

activities on or near roads, trails, or networks;

• Loss and resulting fragmentation of habitat due to the establishment of roads, trails, or networks, 

and associated human activities;
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174 – Tahoe National Forest

• A physical human-induced change in the environment that provides access for competitors or 

predators that would not have existed otherwise;

• Reduction in density of snags and down logs due to their removal near roads as facilitated by road 

access;

• Displacement of individual animals from a specific location that is being used for reproduction 

and rearing of young (i.e. fawning habitat); and

• Increase in heart rate or stress hormones when near a road or trail or network of roads or trails.

Wide-Ranging Carnivores Species Group:

Environmental Consequences

Direct and Indirect Effects Common to All Wide-ranging Carnivores

Cross Country Travel: Wide ranging species would benefit under the action alternatives from the 

prohibition of cross country travel on NFS lands including areas that were previously prohibited to cross 

country motorized use. Under Alternative 1, cross country travel would continue on all NFS lands, except 

for areas previously prohibited to motorized use. Under Alternative 2, cross country travel would be 

prohibited on 715,200 acres of habitat. For Alternative 6, cross country travel would be prohibited on 

717,600 acres of habitat and for the remaining action alternatives, cross country travel would be 

prohibited on 717,900 acres of habitat.

Establishment of Motorized “Open Areas”: In addition to the discussion in Effects Common to All 

Species, the following additional discussion for wide-ranging carnivores is pertinent. 

The three reservoir areas Boca, Stampede, and Prosser would be designated open for Alternative 2 on 

almost 2,700 acres (when combined with the designation of the Greenhorn Area) and for Alternative 3 on 

almost 300 acres. The reservoirs occur on the Truckee Ranger District within eastside pine habitat. 

Eastside pine habitat is generally lower in elevation than where wolverine and the Sierra Nevada red fox 

are known to occur (subalpine and alpine habitats) during the summer months when the reservoirs are 

used for recreational activities, and therefore would not affect wolverine and the red fox. Bear, wolverine, 

or red fox traveling in vicinity of the reservoirs may have minor and incidental direct impacts from 

disturbance. The area used to access the reservoirs has no vegetation, and therefore does not provide 

cover or forage habitat for bear, wolverine, and red fox. Overall, access to the three reservoirs would have 

no to minimal direct or indirect impacts to wide-ranging species.

Changes to the NFTS (Changes in Season of Use): Alternatives 4, 5, and 6 would impose wet 

weather seasonal restrictions on all native surfaced roads and trails, where wide-ranging species would be 

benefited through the reduction of noise and disturbance associated with motorized use, especially 

motorized routes that are within wide-ranging species habitats. Alternatives 1, 2, 3, and 7 do not impose 

wet weather restrictions on native surfaced motorized routes and therefore, there would be no benefit to 

wide-ranging species from wet weather seasonal restrictions under these alternatives.

Amendments to the Forest Plan: Under Alternatives 2, 5, and 6, an amendment to the Forest Plan 

would remove the Tahoe NF Forest Plan direction to restrict motorized vehicle use within key deer winter 
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Tahoe National Forest – 175

range in Management Area 84 (Humbug-Sailor) from November 1 to May 1. Alternatives 1, 3, 4, and 7 

would not have an amendment. Currently the area receives high recreational use, especially during the 

summer months. Implementing these alternatives would likely have a slight negative impact from 

potential disturbance to animals including bear, wolverine, and red fox. However, since the area receives 

concentrated recreational use, it likely does not currently provide high quality habitat for these species, 

particularly the wolverine and red fox, since the wolverine likely would avoid areas with concentrated 

human activity. Additionally, the area does not provide high quality wolverine denning habitat such as 

subalpine habitat with late persistent snow into the spring months. Overall, the potential for adverse 

effects would be minimal and would not likely be measurable, since these species are wide-ranging in 

nature.

Wide-ranging Carnivores Species Group: 

Cumulative Effects

The geographic boundary for analyzing cumulative effects to wide-ranging species (wolverine, Sierra 

Nevada red fox, and bear) are lands that fall within the boundary of the Tahoe NF including all NFS lands 

and non-NFS lands (private). The Tahoe NF boundary is sufficiently large to encompass the home ranges 

of wide-ranging species located on the Tahoe NF. In addition, the Forest boundary encompasses a wide 

variety of habitats used by these species, from early-seral to late-seral forests, subalpine and alpine

habitats, meadows and riparian habitats, and oak and oak-conifer woodlands. The cumulative effects of 

past actions rely upon current environmental conditions as a proxy. As previously stated, existing 

conditions reflect the aggregate impact of all prior human actions and natural events that have affected the 

environment and might contribute to cumulative effects. However, some past actions are presented in 

order to describe potential habitat changes of wide-ranging species that have occurred in the past.

The timeframe for analyzing cumulative effects of reasonably foreseeable future actions for wideranging species is approximately twenty years into the future. Twenty years into the future is a reasonable 

amount of time to estimate potential cumulative impacts to wide-ranging species from future foreseeable 

activities. The cumulative effects to wide-ranging carnivores are discussed for each species in the sections 

below.

Black Bear: Affected Environment

The black bear is a Management Indicator Species on the Tahoe NF. The Tahoe LRMP describes 

important bear habitat as all forested types, particularly in the early- and late-seral vegetation types. 

California Wildlife Habitat Relationships program (CWHR 2005) describes black bear habitats as dense, 

mature stands of forest habitats, and black bears feed in a variety of habitats including brushy stands of 

forest, valley foothill riparian and wet meadows. Habitat requirements include large trees and various 

cavities and hollows in trees, snags, stumps, logs, uprooted trees, talus slopes, or earth dens. Large 

undeveloped blocks of habitat, where bears will encounter few humans in the core areas within these 

blocks, are assumed to be important for black bear.
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176 – Tahoe National Forest

Black bears have been known to be affected by road and trail associated factors including collisions, 

hunting, poaching, negative human interactions, and displacement or avoidance (Gaines et al. 2003). On 

the Tahoe NF, bear collisions have been reported at various locations, primarily along state highways such 

as Interstate 89 and Interstate 49. The frequency of bear-vehicle collisions is relatively low.

Collisions, Hunting and Poaching: The California Department of Fish and Game (2004) report that 

the level of bear-vehicle collisions are low, and most probably occur on higher speed paved highways. 

Collisions on lower speed unpaved routes being evaluated for this project are not likely to occur.

Increased road density likely has an indirect impact on bears by increasing bear and human 

interaction, such as providing increased access to hunters. Bear harvest varies by habitat and accessibility 

to bear habitat. Bears are most vulnerable to harvest where road densities are high and escape cover is 

limited. The amount of human access for bear hunting and poaching opportunities is directly related to the 

proportion of roads and trails. As routes increase on the Tahoe NF, access for bear hunting and poaching 

increase. However, statewide bear monitoring indicates bear population trends are either stable or 

increasing. CDFG (2004) reports that legal and illegal bear harvest together “will not have significant 

negative effects on the State’s bear resource.” Therefore, it is possible to assume that human access for 

bear hunting and poaching does not have a negative impact on the bear population numbers on the Tahoe 

NF.

Negative Bear-Human Interactions: As human access increases, the potential for negative human 

interactions with bears also increases. On the Tahoe NF, negative bear-human interactions have primarily 

occurred at campgrounds, ski resorts, developed recreational facilities, etc. As bear populations in the 

Sierra Nevada continue to increase, bear-interactions on the Tahoe NF are also expected to increase. Bear 

mortalities may result from repeated negative bear-human interactions, but the number of bear killed as a 

result of these negative encounters is not expected to affect the overall bear population on the Tahoe NF.

Displacement or Avoidance: Little research has been conducted on the impacts on black bears from 

recreation in relation to the use of roads and trails. Therefore, impacts to black bears from OHV activities 

associated with roads and trails are not well understood. However, in Idaho, black bears are reported to 

respond to increases in road density by shifting their home ranges to areas of lower road densities (Young 

and Beecham 1986 In Joslin and Youmans, coordinators 1999). In Montana, Kasworm and Manley (1990) 

found that black bears avoided habitat within 274 meters of roads. Bears were more likely to be displaced 

by roads than by trails. A study in North Carolina indicated that road density had no effect in bear 

movement within their home ranges (Brody and Pelton 1989 In Joslin and Youmans, coordinators 1999).

Black Bear: Environmental Consequences

Black Bear: Indicators used to Measure Effects

The analysis measures used to analyze direct, indirect effects, and cumulative effects of the proposed 

alternatives for black bear are:

Cross Country Travel: Motorized cross country travel is analyzed to determine how black bear 

habitat is affected.
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Tahoe National Forest – 177

Establishment of Motorized “Open Areas”: The establishment of motorized “Open Areas” is 

analyzed under effects common to all wide-ranging species.

Additions to the NFTS (Zone of Influence): Additions to the NFTS are measured by the Zone of 

Influence of motorized miles of route additions. Kasworm and Manley’s (1990) studies in Montana found 

that black bears avoided habitat within 274 meters of roads. Although the habitat conditions on the Tahoe 

NF are quite different, a Zone of Influence of 274 meters from motorized routes will be used as an 

approximate analysis measure to compare alternatives for relative habitat effectiveness.

Changes to the NFTS: Change in class of vehicles is analyzed under environmental consequences 

common to all species and change is season of use is analyzed under environmental consequences

common to all wide-ranging species. Reopening of Maintenance Level 1 roads are analyzed for bear by 

determining the Zone of Influence within 274 meters of Level 1 roads that would be reopened. 

Black Bear: Direct and Indirect Effects

Cross Country Travel: Alternative 1 poses the greatest risk to black bear from the continuance of cross 

country travel on existing unauthorized routes, where 20% of bear habitat would be negatively influenced 

within 274 meters. The action alternatives benefit black bear habitat where cross country travel would be

prohibited, including within 18% to 20% (Alternatives 5 and 6 would be the least percent prohibited, 

Alternatives 2, 3, 4, 7 would be the most percent prohibited) habitat within 274 meters of motorized 

unauthorized routes. Under the action alternatives, bear would benefit from the ban on cross country 

travel and associated concentrated use on unauthorized routes, resulting in increased bear habitat 

effectiveness by approximately 18% (Alternatives 5 and 6) to 20% (Alternatives 3 and 7). 

Additions to the NFTS (Zone of Influence): Table 3.03-5 displays the direct, indirect, and 

cumulative effects to bear habitat within a 274-meter Zone of Influence of motorized miles of road/trail

additions. As stated above, Alternative 1 reduces bear habitat effectiveness to the greatest extent (20%) 

because motorized use can be expected to continue on unauthorized routes during continued cross country

travel where bear habitat effectiveness could be reduced or where negative bear-human interactions have 

the potential to occur. 

Motorized routes added to the NFTS under the action alternatives would directly and indirectly 

influence from 0% to 2% bear habitat on the Tahoe NF, which would not measurably affect overall bear 

habitat effectiveness.

Changes to the NFTS: Table 3.03-5 indicates that Alternative 5 proposes reopening ML 1 roads 

which may negatively affect 1% of bear habitat on the Tahoe NF. Alternatives 4, 6, and 7 propose to 

reopen ML1 roads that many negatively affect less than 1% of bear habitat on the Tahoe NF. Affecting 1% 

bear habitat should not reduce the overall habitat effectiveness, but may increase bear disturbance or 

increased bear-human interactions at a local level. The remaining alternatives do not propose to reopen 

any existing ML 1 roads, and therefore would not increase bear-human interaction potential and would

not affect bear habitat effectiveness.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

178 – Tahoe National Forest

Table 3.03-5. Proportion of Black Bear Habitat within a 274-meter “Zone of Influence” of Motorized Routes

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Direct and Indirect Effects of Proposed Alternatives

Proposed motorized route additions to NFTS (negative 

impact)* 20% 2% 0% 1% 1% 2% <1%

Reopened Maintenance Level 1 roads (negative impact) 0% 0% 0% <1% 1% <1% <1%

Cumulative Effects of Past, Present, and Proposed Actions

Existing motorized routes - NFS lands (negative impact) 28% 28% 28% 28% 28% 28% 28%

Existing motorized routes - non-NFS lands (negative impact) 15% 15% 15% 15% 15% 15% 15%

Positive Cumulative Effects (Past Actions)

Decommissioned and Roads Closed in Previous NEPA

(positive impact)

4% 22% 23% 23% 21% 22% 23%

Total Cumulative Effects

Overall Relative Cumulative Impact Score = Sum Total of 

Motorized Routes both positive and negative (Note: Some 

overlap may occur where route categories intersect)

63% 45% 43% 44% 46% 44% 43%

*Motorized route additions: Alternative 1 includes existing unauthorized routes and use associated with continued cross country 

travel.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 179

Black Bear: Summary of Direct and Indirect Effects

Table 3.03-6 summarizes the overall net effect to black bear from the proposed actions from motorized route additions, prohibition of cross 

country travel, wet weather restrictions, and seasonal closures.

Table 3.03-6. Black Bear: Summary of Overall Net Direct and Indirect Effect

Indicator Alt 12 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres of Habitat Where Cross 

Country Travel is Prohibited

0 715,200 717,900 717,900 717,900 717,600 717,900

ZOI Percentage Affected1 0% 19% 20% 19% 18% 18% 20%

Proposed Motorized Route Additions to NFTS

% ZOI Affected 20% 2% 0% 1% 1% 2% <1%

Establishment of Motorized 

“Open Areas”

No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Changes to 

the NFTS

Change in Class of 

Vehicles

No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Wet Weather 

Restrictions

No Effect No Effect No Effect Slight benefit from 

reduced 

disturbance

Slight benefit from 

reduced 

disturbance

Light benefit from 

reduced 

disturbance

No Effect

Reopened ML 1 

Roads (miles)

0 0 0 0.12 93.4 11.4 1.1

Amendments to the Forest Plan No Effect Localized

disturbance in 

winter months

No Effect No Effect Localized 

increased 

disturbance in 

winter months

Localized 

increased 

disturbance in 

winter months

No Effect

Overall Net Effect of Proposed 

Actions

Negatively affects 

black bear habitat 

where cross 

country travel 

continued, 

including within 

20% habitat within 

ZOI 

Benefits black bear 

habitat where 

cross country 

travel is prohibited,

including within 

19% habitat within 

ZOI; although 

minor negative 

effects from route 

additions; overall 

reduces habitat 

fragmentation

Benefits black bear 

habitat where 

cross country 

travel is prohibited, 

including within 

20% habitat within 

ZOI

Benefits black bear 

habitat where 

cross country 

travel is prohibited, 

including within 

19% habitat within 

ZOI; although 

minor negative 

effects from route 

additions; overall 

reduces habitat 

fragmentation

Benefits black bear 

habitat where 

cross country 

travel is prohibited, 

including within 

18% habitat within 

ZOI; although 

minor negative 

effects from route 

additions; overall 

reduces habitat 

fragmentation

Benefits black bear 

habitat where 

cross country 

travel is prohibited, 

including within 

18% habitat within 

ZOI; although 

minor negative 

effects from route 

additions; overall 

reduces habitat 

fragmentation

Benefits black bear 

habitat where 

cross country 

travel is prohibited, 

including within 

20% habitat within 

ZOI; although 

minor negative 

effects from route 

additions; overall 

reduces habitat 

fragmentation

1

Zone of Influence is habitat within 274 meters of existing unauthorized routes 

2

Alternative 1 includes existing unauthorized motorized routes that would continue with cross country travel, while all the action alternatives include proposed route additions.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

180 – Tahoe National Forest

Black Bear: Cumulative Effects

The geographic boundary for analyzing cumulative effects to bear are lands that fall within the boundary 

of the Tahoe NF including all NFS lands and non-NFS lands (private). The Tahoe NF boundary is 

sufficiently large to encompass the home range of bears located on the Tahoe NF. In addition, the Forest 

boundary encompasses a wide variety of habitats used by the bear--from early-seral to late-seral forests, 

meadows and riparian habitats, and oak and oak-conifer woodlands. The timeframe for analyzing 

cumulative effects for the bear is approximately twenty years into the past and into the future. Twenty 

years into the future is a reasonable amount of time to estimate potential cumulative impacts to bear from 

future foreseeable activities.

Cumulative Effects from Motorized Routes: 

Zone of Influence: The cumulative effects of existing authorized motorized routes on both NFS and 

non-NFS lands are displayed in Table 3.03-5 above. Cumulative effects of existing authorized motorized 

routes on NFS and non-NFS lands would influence 28% and 15%, respectively. 

Route Density: Route density is a useful way to measure cumulative effects to bear from the sum 

total of all relevant past, present, and reasonably foreseeable future impacts associated with motorized 

routes. To assess the extent the action alternatives may influence bear habitat, including effects from 

hunting, poaching, and displacement, the density of motorized roads/trails across the Tahoe NF (includes 

both NFS and non-NFS lands) was determined by 7th field watersheds (Table 3.03-7). Motorized route 

density thresholds for black bear are not readily available in the literature, however, Hurley et al. (1981) 

recommended that preferred black bear habitat (high capability) has road densities below 0.5 miles per 

square mile, and moderate habitat capability has road densities below 5 miles per square mile. Therefore, 

bear habitat capability is highest where route density is lowest.

Table 3.03-7 displays percent of black bear habitat in route density categories (low, medium, and 

high), ranging from 0 to greater than 5 miles/square mile. Areas with lower the route densities provide 

higher bear habitat capability where security habitat is provided. Areas with higher route densities provide 

lower habitat capability where security habitat is at greater risk. 

The cumulative effects of route density would be greatest under Alternative 1 (no action) compared to 

all the other alternatives, followed by Alternative 5. Under Alternative 1, approximately 19% of the Tahoe 

NF would be in low habitat capability where route density exceeds 5 miles/square miles, and 

approximately 20% of bear habitat would have reduced effectiveness within 274 meters of unauthorized 

routes. Unmanaged cross country travel would continue and increase over the next 20 years based on the 

increasing trend in sales of ATVs, motorcycles and 4 wheeled drive vehicles in recent years, likely 

resulting in an increase in unauthorized routes. The overall cumulative effects of Alternative 5 would only 

be slightly greater than Alternatives 2, 3, 4, 6, and 7. Alternatives 2, 3, 4, 6 and 7 would have similar 

cumulative effects and would not result in an appreciable change in overall bear habitat capability since 

the addition of unauthorized routes to the NFTS system would only cumulatively add between 0-2 

percent. Refer to Table 3.03-8.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 181

Motorized Route Density: 

• High habitat capability for bear where motorized road/trail densities are less than 0.5 

miles/square mile are similar for all the alternatives ranging from approximately 4 to 7 percent of 

the landscape on the Tahoe NF. 

• Moderate habitat capability for bear (where motorized road/trail densities fall between 0.5 and 5 

miles/square mile), would be the lowest in Alternative 1 (77%). The remaining alternatives 

provide similar amounts of moderate habitat capability for bear, ranging from about 86 to 88

percent. 

• Low bear habitat capability has the highest route density at greater than 5 miles/square mile.

Alternative 1 has the greatest amount of low habitat capability for bears at 19% of the Forest 

compared to all the alternatives. Alternative 5 provides the next highest amount of low capability 

bear habitat. The rest of the alternatives are similar in the amount of low bear habitat capability 

ranging from 6-7 percent.

Table 3.03-7. Black Bear: Percentage of Tahoe NF within high, moderate, and low habitat capability

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Motorized Route 

Density

(Percent of 

Habitat in Route 

Density 

Categories) 

High Capability 

(Lowest Route Density - 0-

0.5 Miles/Square Mile)

4.1% 6.5% 6.5% 6.5% 6.5% 6.5% 6.5%

Moderate Capability 

(Moderate Route Density -

0.5-5 Miles/Square Mile)

77.0% 87.0% 87.6% 87.0% 86.3% 87.0% 87.0%

Low Capability

(Highest Route Density - >5 

Miles/Square Mile)

18.9% 6.6% 6.0% 6.6% 7.2% 6.6% 6.6%
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

182 – Tahoe National Forest

Table 3.03-8. Black Bear: Cumulative Effects Summary

Alternatives Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Past and Present Effects –

Proportion of Forest with 

low bear habitat capability 

(>5mi/square mile)

18.9% 6.6% 6.0% 6.6% 7.2% 6.6% 6.6%

Future Effects –

Likelihood of increased 

route density contributing 

to low bear habitat 

capability

High potential for 

adversely affecting 

bear habitat 

capability from 

Unmanaged cross 

country travel will 

continue and 

increase over time

Low potential for 

adversely affecting 

bear habitat 

capablity, since 

cross country travel 

would be prohibited

Low potential for 

adversely affecting 

bear habitat 

capablity, since 

cross country travel 

would be prohibited

Low potential for 

adversely affecting 

bear habitat 

capablity, since 

cross country travel 

would be prohibited

Low potential for 

adversely affecting 

bear habitat 

capablity, since 

cross country travel 

would be prohibited

Low potential for 

adversely affecting 

bear habitat 

capablity, since 

cross country travel 

would be prohibited

Low potential for 

adversely affecting 

bear habitat 

capablity, since 

cross country travel 

would be prohibited

Overall Cumulative 

Effects 

Lowest Habitat 

capability. Bear 

Habitat Capability 

is likely to be 

reduced in the long 

term.

2nd most beneficial 

alternative, shared 

with alternatives 4, 

6, & 7.

Bear Habitat 

Capability would 

improve compared 

to existing situation

from reduced route 

densities.

Most beneficial 

alternative, no 

motorized route 

additions.

Bear Habitat 

Capability would 

improve compared 

to existing situation 

from reduced route 

densities.

2nd most beneficial 

alternative, shared 

with alternatives 2, 

6, & 7.

Bear Habitat 

Capability would 

improve compared 

to existing situation 

from reduced route 

densities.

Least beneficial 

alternative. 

Bear Habitat 

Capability would 

improve compared 

to existing situation 

from reduced route 

densities, however 

route densities 

would be slightly 

greater than Alts 2, 

4, 6, & 7.

2nd most beneficial 

alternative, shared 

with alternatives 2, 

6, & 7.

Bear Habitat 

Capability would 

improve compared 

to existing situation 

from reduced route 

densities.

2nd most beneficial 

alternative, shared 

with alternatives 2, 

4, & 6.

Bear Habitat 

Capability would 

improve compared 

to existing situation 

from reduced route 

densities.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 183

Overall Cumulative Effects from Past, Present and Reasonably Foreseeable Future Actions: 

Appendix H (Reasonably Foreseeable Projects and Cumulative Effects) provides a list and description of 

past, present, and reasonably foreseeable projects on private lands within the Tahoe NF boundary. Past 

and current cumulative effects to bear include loss of habitat through catastrophic wildfires; timber and 

fuels management where cover and forage has been reduced or removed; urban development and 

expansion within a highly checkerboard land ownership pattern; and recreational activities including 

hunting, camping, and general recreation activities including all forms of motorized use including 4 wheel 

drive vehicles, ATVs, and motorcycles.

Since 1990, more than 130,000 acres of vegetation management activities have occurred on the Tahoe 

NF. Some, but not all, have resulted in impacts to habitats for bear. Between 2001 and 2008, nearly 

17,000 acres of forest vegetation and fuels projects were completed, which primarily thinned, masticated, 

and/or burned vegetation to reduce the potential for catastrophic wildfires. In general, management 

treatments which maintain cover and/or enhance foraging habitat for bear should benefit the bear, 

particularly projects that would promote bear forage species, such as fruit bearing shrubs and forbs.

Vegetation and fuels treatments generally do not increase forage quality and quantity for bear because 

they do not usually result in reducing the canopy cover below 40%. Higher canopy cover would not 

increase the production of understory species important for bear foraging. These treatments may result in 

the short-term reduction in cover for the bear, though it is expected that in the longer term, habitat will be 

protected by reducing wildfire risk. Between 1994 and 2008, approximately 95,000 acres of NFS lands 

burned on the Tahoe NF, some of which have removed forested habitat for bear. 

Thinning projects designed to reduce hazardous fuels will continue to be the primary activity 

affecting wide-ranging species habitat on the Tahoe (see Appendix H, Reasonably Foreseeable Projects 

and Cumulative Effects). It is expected that suitable habitat would be maintained, and it is anticipated that 

these treatments would reduce the amount forested wildlife habitat potentially lost from future stand 

replacing wildfires (USDA Forest Service 2004). The California Department of Forestry and Fire 

Protection currently lists approximately 12,000 acres of private land within the Tahoe NF administrative 

boundary for which timber harvest plans have been submitted. Timber harvest on private lands is 

generally more intensive and often changes the amount of forest cover available, but may increase 

foraging availability by increasing shrub habitats, particularly for bear.

Currently, there is a high demand for recreational use on the Tahoe NF due to its close proximity to 

urban centers. The Tahoe NF provides a wide variety of recreational experiences including developed and 

dispersed camping, hiking, fishing, hunting, wildlife viewing, winter sports activities (downhill skiing, 

cross country skiing, snowmobiling), summer OHV use, and a variety of other non-motorized use 

(equestrian use and mountain biking). Recreational use on the Tahoe NF has significantly increased 

compared to the past 20 to 30 years. Because of the proximity to urban areas and population growth, 

increased recreational use on the Tahoe NF is expected to continue to increase in the future including 

camping, hiking, fishing, wildlife viewing, hunting, and OHV use. Generally, the increase in recreational 

use on the Tahoe NF has the potential to cause an increase in negative interactions between humans and 

bears. Developed recreational sites such as campgrounds and other facilities have the potential to be bear 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

184 – Tahoe National Forest

attractant sites. Currently the Tahoe NF has a number of developed campgrounds and an unknown 

number of dispersed camp sites. Future increase in recreational use on the Tahoe NF is expected, and 

therefore, increased negative human-bear interactions would be expected, particularly during the summer 

months. Appendix H lists the reasonably foreseeable recreation projects that are expected to occur. Two 

non-motorized routes are being proposed for development in the near future. The development and use of 

these routes are not expected to considerably increase human-bear interactions, but rather the sheer 

increase in humans using the Tahoe NF will likely lead to increased negative human-bear interactions. In 

addition, non-motorized use (hiking, mountain biking, equestrian) may occur on existing unauthorized

routes until these areas are revegetated and recovered through active or passive restoration means. It is 

expected that, generally, non-motorized recreation on unauthorized routes is less of an impact than 

motorized recreation due to reduced noise levels, although this is uncertain.

Wolverine and Sierra Nevada Red Fox: Affected Environment

The wolverine and the Sierra Nevada red fox are wide-ranging carnivores that use a variety of vegetation 

types, but appear to select areas that are relatively free from significant human disturbance. Both the 

wolverine and the Sierra Nevada red fox are designated by the Regional Forester in the Pacific Southwest 

Region of the Forest Service as Sensitive.

In the Sierra Nevada, wolverines are known to occur from over 4,000 feet elevation to over 10,000 

feet elevation. According, to Aubrey et al. (2008, pers. comm.), wolverine natal den sites are highly 

correlated with subalpine and alpine regions that have late persistent snow during April and May. Until 

recently, no verified sightings of wolverine have been documented within the State of California since the 

1920’s, though several anecdotal wolverine observations have been reported throughout the Sierra 

Nevada including several apparently reliable observations on the Tahoe NF in recent years. 

In February and March 2008, four verified wolverine photographic detections were taken from 

remote controlled camera stations on the Tahoe NF between the towns of Truckee, CA, and Sierraville, 

CA. Wolverine photographs were documented from four separate baited camera locations. Genetic results 

indicate the DNA evidence that has been collected to date is from a single individual male. DNA testing 

also indicates this individual is not related to the wolverine population from the southern Sierra Nevada 

region and it is also not related to wolverine populations in the Cascades region of Washington state 

(Mike Schwartz, 2008,personal communication). DNA results indicate that this particular wolverine has 

haplotype A, which is ubiquitous and shared with wolverine populations in the Rocky Mountains, 

Canada, and Alaska. At this time, the origin of this individual is unknown. Given the results of DNA 

testing, three possibilities remain of this wolverine’s origin: (1) it escaped from captivity, (2) it dispersed 

from the nearest known populations in the Rocky Mountains or (3) it is from native northern Sierra 

Nevada population that was previously undetected by Grinnell et al. (1937).

Between December 2008 and February 2009, Sierra Pacific Industries (SPI) documented nine 

additional verified wolverine detections on SPI lands located northwest of the four original Tahoe NF 

detections, ranging from the Henness Pass vicinity heading northwest near the town of Bassetts.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 185

Subsequent DNA analysis indicated the wolverine detections on SPI lands were the same male detected in 

February/March 2008.

Wolverines are known to be sensitive to humans and road associated factors, but are not necessarily 

affected by summer recreation trails (Gaines et al. 2003). Gaines et al. (2003) reported that wolverines 

may be displaced from natal dens in subalpine cirques as a result of winter recreation activities.

Road and trail-associated factors that may affect wolverine include reduction in down logs, trapping, 

disturbance at a specific site, and vehicle collisions. Road density can be used as a relative measure of 

human influence on the wolverine, though no empirical data exist which correlate motorized route density 

with wolverine population numbers due to the scarcity of research, the low population numbers, and 

overall difficulty in studying species that encompass large home ranges. Studies indicate that home ranges 

in North America may vary from less than 38.6 square miles to over 347.5 square miles.

The current distribution and population status of the Sierra Nevada red fox is uncertain (CDFG 2004). 

The Sierra Nevada red fox has not been verified to occur on the Tahoe NF, though habitat for this species 

occurs within subalpine conifer habitats interspersed with meadows. The nearest known population of the 

native Sierra Nevada red fox is a small population located in the Lassen Peak vicinity (Lassen National 

Park and Lassen National Forest) which represents the only verified detections of the subspecies in recent 

years (Perrine 2005, Perrine et al. 2007). Road construction and increased human settlement in the Sierra 

Nevada has the potential to facilitate the dispersal of non-native red foxes into the historic range of the 

Sierra Nevada red fox, by providing access to areas previously unavailable to the exotic foxes. Roads 

provide a potential travel corridor for valley foxes to move into Sierra Nevada red fox habitat. Although 

the tolerance of Sierra Nevada red fox to the presence of humans is an unknown, it is evident that the nonnative red foxes thrive in human-altered environments (Lewis et al. 1999, Kamler and Ballard 2002). In 

addition, urban development within the range of Sierra Nevada red fox may pose a risk to the species 

through an increased risk of predation from domestic pets, disease transmission, automobile collisions, 

and other human-wildlife conflicts.

Wolverine and Sierra Nevada Red Fox: Environmental Consequences

Wolverine and Sierra Nevada Red Fox: Indicators used to Measure Effects

Cross Country Travel, Changes to the NFTS (Change in Class of Vehicles and Changes is Season of 

Use): The prohibition of cross country travel and Changes to the NFTS (the change in class of vehicles 

and changes to season of use) are discussed under “Wide-ranging Carnivores Species Group: 

Environmental Consequences.”

Establishment of Motorized “Open Areas”: The establishment of motorized “Open Areas” is 

analyzed under effects common to all wide-ranging species.

Zone of Influence: The Zone of Influence within 60 meters of routes (route miles buffered by 60 

meters on each side of route added) was used as a measure for analyzing habitat fragmentation as it 

pertains to loss of snags and down logs along routes within mature to late-seral coniferous forest habitat 

as classified by 4M, 4D, 5M, 5D, and 6 CWHR types within the Tahoe NF. Sixty meters is the maximum 

distance within which the removal of hazard trees for roads and trails would occur where logs and snags 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

186 – Tahoe National Forest

important for wolverine and red fox may be lost due to public safety concerns. Additional analysis of 

habitat fragmentation is presented within Old Forest Emphasis Areas (OFEAs) and within the Tahoe NF 

Forest Carnivore Network, which is presented in the section for Late-seral coniferous Forest Associated 

Species Group.

Disturbance to a Specific Site (Wolverine only): The Sierra Nevada Forest Plan Amendment (2004) 

directs that upon detection of a verified wolverine, management impacts within 5 miles of the verified 

detection be analyzed. Activities associated with motorized routes represent potential direct disturbance to 

wolverine using the area. Therefore, the miles of routes proposed to be added to the NFTS within five 

miles of verified wolverine photographic detection sites on the Truckee and Sierraville Ranger Districts of 

the Tahoe NF and on Sierra Pacific Industries lands were evaluated for each of the action alternatives. 

Several studies indicate wolverine den sites are strongly associated with subalpine or treeline habitats, 

and have late persistent snow during the months of April and May (Banci 1994, Aubry et al. 2007, 

Copeland et al. 2007, Aubry et al. 2008 – pers. com.). On the Tahoe NF, subalpine and treeline habitats 

generally occur near or above 8,000 feet; areas that have late spring, deep, persistent snow vary 

depending on the precipitation and the aspect. Activities associated with motorized routes are assessed for 

their potential to disturb wolverine den sites.

Changes to the NFTS (Reopened ML 1 Roads): Reopening ML 1 roads also have the potential to 

increase disturbance and fragment habitat within close proximity to known wolverine detections. The 

alternatives are analyzed for their potential to impact areas within 5 miles of known wolverine detections 

on the Tahoe NF.

Amendments to the Forest Plan: Amendments to the Forest Plan is analyzed under effects common 

to all wide-ranging species.

Wolverine and Sierra Nevada Red Fox: Direct and Indirect Effects

Cross Country Travel: Except for Alternative 1, no action, all the action alternatives would benefit the 

wolverine and red fox and their habitats, since 81,884 acres of habitat would be prohibited to cross 

country travel. Therefore, disturbance, avoidance and displacement to these species would be reduced 

under the action alternatives.

Additions to the NFTS and Reopened ML 1 Roads

Zone of Influence: Snags and down logs are important habitat components for wolverine and red fox. 

Habitat fragmentation, as measured by potential impacts to snags and down logs that may be removed for 

public safety, is determined by assessing the Zone of Influence within 60 meters of added motorized 

routes. The Zone of Influence within mature forest (CWHR 4M, 4D, 5M, 5D, 6), Old Forest Emphasis 

Areas, and the Tahoe NF Carnivore Network are analyzed for their potential impact of habitat 

fragmentation (potential loss of snags and down logs) along all motorized routes. These habitat types 

serve as a broad landscape proxy to evaluate habitat connectivity and fragmentation for mature and old 

forest conditions that are important for wide-ranging species such as the wolverine and Sierra Nevada red 

fox.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 187

Motorized routes to be added to the NFTS are evaluated for each alternative as it relates to habitat 

fragmentation for the wolverine and the Sierra Nevada red fox. From a Forest-wide landscape 

perspective, Alternative 1 would contribute to the highest amount of potential habitat fragmentation 

through the incidental loss of snags and down logs on approximately 6% of mature and late-seral

coniferous forest habitat by allowing cross country motorized use, including use on approximately 291 

miles of identified motorized unauthorized routes, to continue on the Tahoe NF (Table 3.03-9). 

Alternatives 2, 4, 5, 6, and 7 all minimally affect landscape fragmentation through potential loss of down 

logs and snags that may be removed for public safety, at less than 1% or between 0.5 miles and 7.8 miles. 

Alternative 3 would not contribute to habitat fragmentation since unauthorized routes would not be added 

to the NFTS under this alternative.

Reopened ML 1 roads would contribute to less than 1% for Alternatives 2, 4, 5, 6, and 7, with 

Alternative 5 contributing to the greatest amount of potential loss in snags and down logs along 32.8 

miles or 0.4% of old forest CWHR habitat within a 60 meter zone of influence, followed by Alternatives 

6, 4, 2, and 7 in descending order. Alternatives 2, 4, 6, and 7 should not significantly affect the amount of 

available snags and down logs at the Forest-wide scale considering that less than 0.1% of Old Forest 

CWHR habitat types could be impacted by the incidental of removal of snags for public safety, and 

considering that the development and recruitment of snags and down logs is a dynamic process.

Table 3.03-9. Percent of NFS lands within a 60 meter “Zone of Influence” of motorized route additions and 

reopened ML 1 roads within Old Forest Habitat (CWHR 4M, 4D, 5M, 5D, and 6)

Alternatives Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Zone of Influence (Motorized Additions) 7% 0.3% 0% 0.1% 0.4% 0.3% 0.2%

Miles Added 290.9 4.4 0 0.5 7.5 7.8 0.9

Zone of Influence (Reopened ML1 Roads) 0% <0.1% 0% <0.1% 0.4% <0.1% <0.1%

Miles of ML1 Roads Reopened 0.0 1.2 0.0 1.7 32.8 3.9 0.7

*Alternative 1 includes existing unauthorized routes

Disturbance to a Specific Site (Wolverine only): The Sierra Nevada Plan Amendment Standard and

Guideline #32 (SNFPA ROD 2004) directs that upon detection of a verified wolverine, an analysis be 

conducted to determine if activities within 5 miles of the detection have the potential to affect the species. 

Thirteen individual, verified wolverine detections were documented on the Tahoe NF and SPI lands 

during the winters of 2008 and 2009. For this analysis, the miles motorized routes that are proposed to be 

added to the NFTS under each alternative were evaluated to determine the potential for motorized use to 

disturb wolverine that may be foraging or traveling through the area within 5 miles of the thirteen verified 

wolverine detections. Generally, wolverines move up into the higher elevation subalpine and treeline 

environments during the breeding period (January 1 to June 30). High elevation subalpine and alpine 

habitat within close proximity to the wolverine detection sites occurs at Mt. Lola, Basin Peak and Castle 

Peak with elevations above 8,000 feet. Mt. Lola is the nearest location with subalpine and treeline 

conditions to the verified wolverine detections. It is unknown whether the wolverine that was detected 

during February and March of 2008 on the Truckee and Sierraville Ranger Districts would be in the 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

188 – Tahoe National Forest

vicinity where it was originally detected during the time when the majority of motorized use would occur. 

However, if wolverine are foraging or traveling in an area when motorized use occurs, Alternative 1 

results in the greatest miles of routes within 5 miles of verified wolverine detections where direct 

disturbance could potentially occur (Table 3.03-10) within the 5 miles. Alternative 5 results in the next 

greatest potential disturbance to wolverine by activities associated with motorized unauthorized routes

that would be added to the NFTS (9 miles), followed by Alternatives 2, 6, 7, and 4 in descending order. 

Alternative 3 does not add any motorized routes to the NFTS, and therefore, would not have any direct 

effects to wolverine within 5 miles of known detection locations.

Effects to potential alpine/subalpine denning habitat above 8,000 feet: The largest and most 

contiguous potential wolverine alpine/subalpine denning habitat within 5 miles of verified wolverine 

detections occurs in the vicinity of Mt. Lola. Smaller alpine/subalpine areas above 8,000 feet are scattered 

near the Pacific Crest trail, Webber Peak, Maiden Valley, and the Sierra Buttes. Generally, areas above 

8,000 feet are primarily non-motorized due to the steep terrain condition and inaccessibility.

None of the proposed route additions for any of the action alternatives falls within the Mt. Lola area. 

The majority of proposed routes additions are located well below alpine/subalpine habitat in areas that 

currently are moderately to highly roaded. Motorized use on the proposed routes would occur when they 

are snow-free and outside of the wet weather seasonal restriction period (Open April 1 to December 31 

and /or May to December 31).

Motorized activities on the proposed route additions for the preferred alternative, Alternative 6, would 

not likely affect denning wolverine habitat and would not require a Limited Operating Period from 

January 1 to June 30. Only Alternative 5 proposes a route addition within a very small isolated habitat 

area above 8,000 feet, just west of Maiden Valley and may not be suitable for wolverine denning due to 

the small area and isolated nature. This small patch of denning habitat is located adjacent to an area with 

an existing high density of motorized routes.

In addition, potential subalpine denning habitat in the Basin Peak and Castle Peak area occur just 

beyond 5 miles of any wolverine detections, and no proposed route additions occur within these areas. All 

the action alternatives benefit wolverine from the ban of cross country travel, including on 93 to 104 

miles (Alternative 5 would benefit the least, Alternative 3 would benefit the most).

Table 3.03-10. Miles of Proposed Motorized Route Addition to the NFTS and Existing Unauthorized Motorized 

Routes within 5 miles of Known Verified Wolverine Detections

Within 5 Miles of Wolverine Detections Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Proposed Motorized Route Additions to NFTS 104 4 0 2 9 3 2

Unauthorized Motorized Routes where cross 

country travel would be prohibited

0 100 104 102 93 101 102

*Alternative 1 includes existing unauthorized routes that are associated with continued cross country travel

Changes to the NFTS (reopened Maintenance Level 1 Roads)

Disturbance to a Specific Site (Wolverine): Alternative 5 has the greatest potential to impact areas 

within 5 miles of known wolverine detections from reopening ML 1 roads, where 7.5 miles would be 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 189

reopened where wolverine could be directly disturbed and habitat could be affected from fragmentation

though snag and down log removal (Table 3.03-11). Alternative 6 proposes to reopen 0.6 miles (SV005), 

which would slightly affect wolverine which could potentially increase disturbance from vehicle related 

noise. However, since wolverine have large home ranges and can travel long distances within a day, 

reopening less than 1 mile of ML 1 road should not be a pose a significant risk to wolverine. The 

remaining alternatives do not propose reopening any ML 1 roads within 5 miles of known detections and 

therefore would not affect wolverine or its habitat within 5 miles of wolverine detections.

Effects to potential alpine/subalpine denning habitat above 8,000 feet: None of the ML 1 roads 

proposed for reopening occurs within alpine/subalpine habitat above 8,000 feet potentially suitable for 

wolverine denning, and therefore there is no need to implement a Limited Operating Period.

Zone of Influence at 60 meters (Disturbance to a Specific site for Wolverine Only): Only 

Alternatives 5 and 6 propose to reopen any ML 1 routes within 5 miles of wolverine detections. The Zone 

of Influence within 60 meters of reopened ML1 routes within 5 miles of wolverine detections was 

determined to affect less than one percent of the area for both Alternatives 5 and 6. Alternative 5 has the 

most potential to directly and indirectly affect wolverine through direct disturbance or habitat 

modification, where approximately 7.5 miles of ML 1 roads would be reopened within 5 miles of known 

wolverine detections (Table 3.03-11). These ML 1 roads are historic roads which were primarily used for 

timber harvest. Alternative 6 proposes to reopen 0.6 miles of ML 1 roads (SV-005) within 5 miles of 

known wolverine detections. Although Alternative 5 affects a slightly greater proportion of wolverine 

habitat than Alternative 6, this amount of motorized influence would not be measurable at the landscape 

scale, and therefore would not likely affect the wolverine either through disturbance or habitat condition.

The remaining alternatives would not reopen any ML 1 roads within 5 miles of known detections, and 

therefore would not directly or indirectly affect the wolverine.

Table 3.03-11. Miles and Zone of Influence of Reopened Maintenance Level 1 Roads within 5 miles of Known 

Verified Wolverine Detections

Alternatives Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

ZOI Percentage Affected (Reopened ML 1 Roads) 0% 0% 0% 0% <1% <1% 0%

Miles of Reopened ML 1 Roads 0 0 0 0 7.5 0.6 0

Wolverine and Sierra Nevada Red Fox: Summary of Direct and Indirect Effects 

Table 3.03-12 summarizes the overall net effect to red fox and wolverine from the proposed actions from 

motorized route additions, prohibition of cross country travel, establishment of “Open Areas,” and 

changes to the NFTS.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

190 – Tahoe National Forest

Table 3.03-12. Wolverine and Sierra Nevada Red Fox: Summary of Overall Net Direct and Indirect Effects

Indicator Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres of Habitat Where Travel is 

Prohibited

0 715,200 717,900 717,900 717,900 717,600 717,900

ZOI Percentage Affected1 0% 6% 6% 6% 6% 6% 6%

Proposed Motorized Route Additions to NFTS

Trend of Effect Negative 

(existing 

unauthorized 

routes)

Negative No effect Negative Negative Negative Negative

% ZOI Affected 6% <1% 0% 0% <1% <1% <1%

Miles Added2 290.9 4.4 0 0.5 7.5 7.8 0.9

Establishment of Motorized “Open 

Areas”

No Effect Localized Adverse 

effects at 

Greenhorn Creek 

(60ac) and Boca, 

Stampede, and 

Prosser 

Reservoirs (2,589 

ac)

No Effect No Effect No Effect Localized minimal 

adverse effects at 

Boca, Stampede, 

and Prosser 

Reservoirs

No Effect

Changes 

to the 

NFTS

Change in Class of Vehicles No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Change in Season of Use No Effect Slight Benefit No Effect Slight benefit 

from reduced 

disturbance

Slight benefit 

from reduced 

disturbance

Light benefit 

from reduced 

disturbance

No Effect

Reopening 

Maintenance 

Level 1 

roads

Trend of 

Effect

No Effect No Effect No Effect No Effect Negative Minimal 

Negative No Effect

ZOI 

Percentage 

Affected

within 5 

miles of 

wolverine 

detections

0% 0% 0% 0% <1% <1% 0%
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 191

Indicator Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Miles of 

Reopened 

within 5 

miles of 

wolverine 

detections 

0 0 0 0 7.5 0.6 0

ZOI 

Percentage 

Affected

within 5 

mi. of 

wolverine 

detections

0% 0% 0% 0% <1% <1% 0%

Miles 

Reopened

within old 

forest 

CWHR 

habitat

0 1.2 0.0 1.7 32.8 3.9 0.7

Amendments to the Forest Plan No Effect Negligible 

localized negative 

effect

No Effect No Effect Negligible 

localized negative 

effect

Negligible 

localized negative 

effect

No Effect

Overall Net Effect (compared to 

Alternative 1)

Negative effects 

because 

unauthorized 

cross country 

travel would 

continue; lowest 

habitat security 

because the most 

habitat is in 

highest route 

density 

categories. 

Beneficial effect 

from prohibited 

cross country 

travel; although 

minor negative 

effects from route 

additions; higher 

habitat security 

from increased 

proportion of 

roads in lowest 

road density 

categories; overall 

reduces habitat 

fragmentation. 

Beneficial effect 

from prohibited 

cross country 

travel; higher 

habitat security 

from increased 

proportion of 

roads in lowest 

road density 

categories. 

Greatest habitat 

security increase 

among the action 

alternatives.

Beneficial effect 

from prohibited 

cross country 

travel; although 

minor negative 

effects from route 

additions;higher 

habitat security 

from increased 

proportion of 

roads in lowest 

road density 

categories; overall 

reduces habitat 

fragmentation.

Beneficial effect 

from prohibited 

cross country 

travel; although 

minor negative 

effects from route 

additions; higher 

habitat security 

from increased 

proportion of 

roads in lowest 

road density 

categories; overall 

reduces habitat 

fragmentation.

Beneficial effect 

from prohibited 

cross country 

travel; although 

minor negative 

effects from route 

additions; higher 

habitat security 

from increased 

proportion of 

roads in lowest 

road density 

categories; overall 

reduces habitat 

fragmentation.

Beneficial effect 

from prohibited 

cross country 

travel; although 

minor negative 

effects from route 

additions; higher 

habitat security 

from increased 

proportion of 

roads in lowest 

road density 

categories; overall 

reduces habitat 

fragmentation..

1

Zone of Influence for Wolverine and Red Fox is 60 m. 

2

Route Miles Added to NFTS: Alternative 1 includes unauthorized routes with continued cross country travel.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

192 – Tahoe National Forest

Wolverine and Sierra Nevada Red Fox: Cumulative Effects 

Cumulative Effects from Motorized Routes: The geographic boundary for analyzing cumulative effects 

to wolverine and the Sierra Nevada red fox are lands that fall within the boundary of the Tahoe NF 

including all NFS lands and non-NFS lands (private). The Tahoe NF boundary is sufficiently large to 

encompass the home ranges of the wolverine and Sierra Nevada red fox located on the Tahoe NF. In 

addition, the Forest boundary encompasses a wide variety of habitats used by the wolverine and red fox:

various forested habitats, subalpine meadow habitats, and riparian streamside habitats. The timeframe for 

analyzing reasonably foreseeable cumulative effects for the wolverine and Sierra Nevada red fox is 

approximately 20 years into the past and into the future, which is a reasonable amount of time to estimate 

potential cumulative impacts to these species from future foreseeable activities.

Motorized Route Density: Motorized route density thresholds for wolverine and Sierra Nevada red 

fox have not been established, and are hard to determine because of the rarity of these species and their 

elusive behavior patterns. Therefore, motorized route density across the Tahoe NF provides a relative 

measure of habitat effectiveness and/or the amount of security habitat available to the wolverine and the 

Sierra Nevada red fox at the broad landscape scale for which to compare the proposed alternatives. Many 

literature references indicate wolverine and red fox are primarily associated with remote, secluded areas 

and may be sensitive to human presence. Therefore, it would follow that as route density increases, 

human presence may also increase and which reduces security habitat for wolverine and red fox. To 

compare alternatives, route density categories between 0 to greater than 6 miles/square mile are presented. 

The motorized route density within 7th field watersheds was determined for all motorized routes 

including those on NFS lands and non-NFS lands. Motorized route density represents the sum total 

cumulative route density for all motorized routes. Since the wolverine is known to avoid areas within high 

concentrations of human presence, security habitat is best provided for where route densities are the 

lowest. In addition, motorized route densities are compared within old forest habitat types (CWHR types 

4M, 4D, 5M, 5D, and6), Old Forest Emphasis Areas, and within the Tahoe NF Forest Carnivore Network 

(See Old Forest Associated Species Section).

Table 3.03-13 provides data on the proportion of lands within the Tahoe NF with motorized route 

densities between 0 and greater than 6 miles/square mile. Alternative 1 has the lowest proportion of land 

with motorized routes density less than 2 miles/square mile (17% - high to moderate security). The 

remaining alternatives are similar in their proportion of land base with motorized route density less than 2 

miles/square mile (25% to 26%). Moderate security habitat represented by motorized route density 

category of 2-4 miles/square mile indicates Alternative 1 provides the least amount (44%) moderate 

security habitat, followed by Alternative 5. The remaining action alternatives provide slightly greater 

amounts of moderately secure habitat. Alternative 1 provides the most amount of area with lower (32% -

4 to 6 mi/sq. mi.) and least secure habitat (7% greater than 6 mi/sq. mi.). Therefore, Alternatives 3, 4, 2, 6, 

7, and 5 in descending order provide the most security habitat for the wolverine and Sierra Nevada red 

fox, and Alternative 1 provides the least amount of security habitat for these two species.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 193

Table 3.03-13. Percent of Tahoe NF with motorized route densities between zero and greater than 6 

miles/square mile

Motorized Route Density Security Risk* Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

0 Miles/Square Mile High Security <1% <1% <1% <1% <1% <1% <1%

0-2 Miles/Square mile Moderately High 

Security

17% 25% 26% 25% 25% 25% 25%

2-4 Miles/Square mile Moderate 

Security

44% 56% 57% 57% 53% 57% 57%

4-6 Miles/Square mile Lower Security 32% 15% 13% 14% 17% 14% 14%

>6 Miles/Square mile Least Security 7% 4% 4% 4% 5% 4% 4%

*Security risk was developed based on a review of literature from various sources on wide-ranging species and professional 

judgment.

The overall cumulative effects to wolverine and Sierra Nevada red fox from motorized routes are 

evaluated by analyzing the effects of the alternatives in terms of motorized route density, habitat 

fragmentation, and disturbance to a specific site (wolverine only) from past, present, and reasonably 

foreseeable actions (Table 3.03-14). Past and present motorized route densities are combined to represent 

the current existing condition. Since no thresholds of motorized route density for these species have been 

established, motorized route density is only used to compare the relative differences between the 

alternatives. Motorized route densities categories greater than 4 miles/square mile (“lower security” and 

“least security”) are used as a metric to compare relative route densities of the alternatives where human 

impacts of motorized routes may render habitat less suitable and/or secure to wolverine and red fox. 

Habitat fragmentation through removal of snags and down logs for public safety is also used to evaluate 

the cumulative impacts of the proposed alternatives.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

194 – Tahoe National Forest

Table 3.03-14. Wolverine and Sierra Nevada Red Fox Cumulative effects from Motorized Route Density, Habitat Fragmentation, and Disturbance to a 

Specific Site

Alternatives Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Present and Past Effects

Acres of Cross Country Travel 

Prohibited

0 715,200 717,900 717,900 717,900 717,600 717,900

Total Combined Percent with route 

density categories of 4 to 6 

Miles/square mile (lower security) 

and >6 miles/square mile (least 

security habitat)

39% 19% 17% 18% 23% 19% 19%

Cumulative Motorized Route Density

Zone of Influence (60 meters) 26% <20% <20% <20% 22% <20% <20%

Miles Added (Disturbance to a 

specific site – within 5 miles of 

wolverine site)

0 4.4 0 0.5 7.5 7.8 0.9

Establishment of Motorized “Open 

Areas”

None Slight Negative 

Effect 

Greenhorn 

Area (60 ac), 

Prosser, Boca, 

and Stampede 

Reservoirs 

(2,589 ac)

None None None Slight negative 

effect at 

Prosser, Boca, 

and Stampede 

Reservoir 

Access Areas 

(244 acres)

None

Changes to 

NFTS

Change in Class of 

Vehicles

No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Change in Season of 

Use

No Effect No Effect No Effect Slight benefit 

from reduced 

disturbance

Slight benefit 

from reduced 

disturbance

Light benefit 

from reduced 

disturbance

No Effect

Miles Reopened ML 1 

Roads (Disturbance to a 

specific site – within 5 

miles of wolverine site)

0 0 0 0 7.5 0.6 0
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 195

Alternatives Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Future Effects

Potential for route proliferation 

contributing to motorized route 

density and habitat fragmentation 

into the future

High potential for 

increased route 

density and 

habitat 

fragmentation in 

the future due to 

unmanaged cross 

country travel

Low potential for 

increased route 

density and 

habitat 

fragmentation–

Cross country 

travel would be 

prohibited

Low potential for 

increased route 

density and 

habitat 

fragmentation–

Cross country 

travel would be 

prohibited

Low potential for 

increased route 

density and 

habitat 

fragmentation–

Cross country

travel would be 

prohibited

Low potential for 

increased route 

density and 

habitat 

fragmentation–

Cross country 

travel would be 

prohibited

Low potential for 

increased route 

density and 

habitat 

fragmentation–

Cross country 

travel would be 

prohibited

Low potential for 

increased route 

density and 

habitat 

fragmentation–

Cross country 

travel would be 

prohibited

Cumulative Effects

Overall Cumulative Effect of past, 

present and future motorized routes 

to wolverine and red fox

Greatest 

cumulative effect 

from route density 

and proportion of 

Forest 

fragmented by 

routes

Cumulative 

effects of route 

density and

habitat 

fragmentation are 

similar to 

Alternatives 3, 4, 

6, 7

Cumulative 

effects of route 

density and 

habitat 

fragmentation are 

similar to 

Alternatives 2, 4, 

6, 7

Cumulative 

effects of route 

density and 

habitat 

fragmentation are 

similar to 

Alternatives 2, 3, 

6, 7

Next highest 

Cumulative effect 

after Alternative 

1, slightly higher 

cumulative effect 

than Alternatives 

2, 3, 4, 6, & 7

Cumulative 

effects of route 

density and 

habitat 

fragmentation are 

similar to 

Alternatives 2, 3, 

4, 7

Cumulative 

effects of route

density and 

habitat 

fragmentation are 

similar to 

Alternatives 2, 3, 

4, 6

*Alternative 1 includes existing unauthorized routes under continued motorized cross country travel.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

196 – Tahoe National Forest

Overall Cumulative Effects from Past, Present, and Reasonably Foreseeable Future Actions: 

Past and current cumulative effects to wolverine and Sierra Nevada red fox include current and historic 

grazing; loss of habitat through catastrophic wildfires; timber and fuels management where cover and 

forage has been reduced or removed; urban development and expansion within a highly checkerboard 

land ownership pattern; and recreational activities including hunting, camping, winter recreation (skiing 

and snowmobiling), and general recreation activities including all forms of motorized use including 4 

wheel drive vehicles, ATVs, and motorcycles.

The Tahoe NF currently has 31 active livestock grazing allotments including both cattle and sheep. 

Tahoe LRMP standards and guidelines, as amended by the Sierra Nevada Forest Plan Amendment (USFS 

2004), for grazing are generally reducing the amount of grazing impacts on rangelands. Improved range 

conditions as a result of implementing the revised grazing standards and guidelines should benefit prey 

species for both the wolverine and red fox, especially as site specific allotment management plans are 

developed.

Since 1990, more than 130,000 acres of vegetation management activities have occurred on the Tahoe 

NF. Some, but not all, have resulted in impacts to habitats for wolverine and red fox. Between 2001 and 

2008, approximately 17,000 acres of forest vegetation and fuels projects were completed, which primarily 

thinned, masticated, and/or burned vegetation to reduce the potential for catastrophic wildfires. It is 

uncertain how vegetation treatments actually affect the wolverine as no empirical data exists on how 

vegetation management affects habitat quality for both the wolverine and the red fox. In general, 

management treatments which maintain or enhance habitat for deer should benefit the wolverine.

Vegetation and fuels treatments generally do not increase forage quality and quantity for deer 

(wolverine prey species) because they do not usually result in reducing the canopy cover below 40%. 

Higher canopy cover would not increase the production of understory species important for deer foraging. 

These treatments may result in the short-term reduction in cover for the California wolverine and the 

Sierra Nevada red fox, though it is expected that in the longer term, habitat would be protected by 

reducing wildfire risk. Between 1994 and 2008, approximately 95,000 acres burned on the Tahoe NF, 

some of which have removed forested habitat for wide-ranging species.

On the Tahoe NF, present and past recreational impacts to the wolverine and red fox are far-reaching. 

The impact of humans from commercial harvest and trapping of wolverine during the turn of the century 

likely significantly contributed to the decline (and potential extirpation) in wolverine compared to historic 

conditions in the Sierra Nevada. The Tahoe NF recreation activities include many forms of recreation 

including both passive and active recreation. Summer recreation includes fishing, hiking, camping at 

developed and dispersed sites, hunting, off highway use, and wildlife viewing. Winter recreation includes 

developed ski areas, cross country skiing, and over snow recreation. Since no scientific studies are 

available that show how these activities impact these species, it is unknown how these recreational 

activities affect the distribution and abundance of wolverine and the red fox. 

The wolverine and the red fox are considered to be primarily associated with areas with low human 

influence, such as remote wilderness and roadless areas. Increased recreational use on the Tahoe NF in the 

near future has the potential to impact wolverine if den sites at high elevation subalpine and alpine areas 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 197

are disrupted during the breeding period (January to June 30). Increases in recreational activities 

associated with motorized routes are generally not likely to affect subalpine and alpine areas considered 

to be suitable for wolverine and red fox denning habitat when they are covered by snow.

When considering all the cumulative effects of past, present, and reasonably foreseeable future 

impacts from vegetation/fuels projects, wildfires, and recreation, Alternative 1 poses the greatest risk to 

the wolverine and red fox on the Tahoe NF, where 39% of the Tahoe NF has motorized route densities 

that fall in the lower security (motorized route density category 4-6 mi/sq. mi.) and least secure 

(motorized route density category greater than 6 mi/sq. mi.) habitat condition, followed by Alternative 5 

(23%). The remaining action alternatives are similar to each other and only slightly increase overall 

cumulative impacts to wolverine and Sierra Nevada red fox on the Tahoe NF. Alternative 3 does not add 

any routes to the NFTS, so it does not add to existing cumulative impacts. All the action alternatives 

would result in a beneficial impact to wolverine prey (mule deer) from the ban of cross country travel on 

over 715,000 acres, including the use on between 257 and 390 miles of existing unauthorized routes, 

depending on the alternative (Alternative 5 least benefit to Alternative 3 greatest benefit), compared to 

Alternative 1.

Non-motorized (hiking, mountain biking, equestrian) use may occur on existing unauthorized routes. 

Generally, it is expected that non-motorized recreation would be less impactive than motorized recreation, 

but the degree of the reduced impact depends upon the type and intensity of non-motorized use. Over 

time, it is expected that these existing motorized routes would eventually become revegetated through 

active or passive restoration. The time of recovery would depend upon the site-specific soil and vegetative 

conditions.

In addition, Alternatives 4, 5, and 6 would benefit wolverine prey on deer winter ranges through the 

implementation of wet weather closures on native surfaced roads and trails. Finally, Alternative 1, with 

continued cross country travel, including continued use of existing unauthorized routes, has the greatest 

number of route miles occurring within a 5-mile radius of verified wolverine detections (104 mi.), 

followed by the remaining alternatives in descending order (Alternative 5, 9 mi.; Alternative 2, 4 mi.; 

Alternative 6, 3 mi.; Alternatives 4 and 7, 2 mi.; Alternative 3, none).

Wolverine and Sierra Nevada Red Fox: Management Direction

Sensitive Species Determination: The Biological Evaluation for the Travel Management EIS project 

(Project file, which is incorporated by reference) made a determination that implementation of Alternative 

6, the Preferred Alternative, may affect the California wolverine and the Sierra Nevada red fox, but is not 

likely to result in a trend toward Federal listing or loss of viability for the California wolverine or the 

Sierra Nevada red fox within the planning area of the Tahoe National Forest. Alternative 6 would prohibit 

current and future cross country travel, including motorized use on 104 miles of unauthorized routes 

within 5 miles of verified wolverine detections, would impact less than 1 % of wolverine and the Sierra 

Nevada red fox habitat, would result in route densities of >4 miles/square mile (low security risk) in 18% 

of the Tahoe NF, would not affect alpine or subalpine habitat above 8,000 feet, and would only add 3 

miles of routes to the NFTS within 5 miles of verified wolverine detections. Beneficial effect from 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

198 – Tahoe National Forest

prohibited cross country travel; although minor negative effects from route additions; higher habitat 

security from increased proportion of roads in lowest road density categories; overall reduces habitat 

fragmentation. In the absence of a range-wide viability assessment, this viability determination is based 

on local knowledge of this species as discussed previously in this evaluation, and professional judgment.

Compliance with the Forest Plan and Other Direction: The Record of Decision (ROD) for the 

2004 Sierra Nevada Forest Plan Amendment identified the following standard and guideline applicable to 

wolverine and red fox was analyzed for the Motorized Travel Management Project:

Wolverine and Sierra Nevada Red Fox Detections: Detection of a wolverine or Sierra Nevada red 

fox will be validated by a forest carnivore specialist. When verified sightings occur, conduct an analysis 

to determine if activities within 5 miles of the detection have a potential to affect the species. If necessary, 

apply a limited operating period from January 1 to June 30 to avoid adverse impacts to potential breeding. 

Evaluate activities for a 2-7 year period for detections not associated with a den site (Standard and 

Guideline 32). This standard and guideline does not apply to the Sierra Nevada red fox because there have 

been no verified detections of it on the Tahoe NF.

The Travel Management Project analyzed how proposed motorized route additions would affect the 

area within a 5 mile radius of known verified wolverine detections. The analysis shows when wolverine 

may be using the area for foraging or traveling when motorized use tends to occur, motorized use has the 

potential to disturb the wolverine. Alternative 1 continues cross country travel, where use on 104 miles of 

unauthorized routes would occur within 5 miles of verified wolverine detections where direct disturbance 

could potentially occur. Alternative 5 results in the next greatest potential disturbance to wolverine by 

activities associated with 9 miles of proposed motorized route additions within 5 miles of known 

wolverine detections, followed by Alternatives 2, 6, 7, and 4 in descending order. Alternative 3 does not 

add motorized trail to the NFTS, and therefore, would not have any direct effects to wolverine within 5 

miles of known detection locations. In addition, the prohibition of cross country travel on approximately 

715,000 acres of habitat across the Forest significantly improves habitat effectiveness for all the action 

alternatives.

Alternative 6 would not propose any route additions to the NFTS or would reopen any ML 1 roads 

within alpine and subalpine areas above 8,000 feet (i.e. Mt. Lola area) that may be suitable for wolverine 

denning habitat, and therefore would not require a Limited Operating Period from January 1 to June 30.

No verified detections of the Sierra Nevada red fox are known at this time, and therefore, a site-specific 

analysis is not warranted.

Mule Deer (Ungulates): Affected Environment

The mule deer is the only species in the Ungulate Species Group. The mule deer is a Management 

Indicator Species on the Tahoe NF. The Tahoe LRMP indicates that mule deer use a mix of all 

successional stages, but the most important mule deer habitat types are early successional types, 

hardwoods, and shrublands. Most deer on the Tahoe NF migrate seasonally between higher elevation 

summer range and low elevation winter range. In general, critical winter range, critical summer range, 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 199

and fawning habitats represent key habitats for deer where heavier use and higher quality habitats for 

wintering and summer use are expected to occur.

The Tahoe National Forest has four main deer herds within its administrative boundaries: 

Downieville, Nevada City, Blue Canyon and Loyalton/Truckee. The Sloat, Mooretown and Doyle herds 

overlap with small portions of the Tahoe NF in the extreme north sections of the administrative 

boundaries and are insignificant on a forest scale.

The Tahoe LRMP currently has restrictions on cross country travel within the four primary deer herd 

boundaries, including Blue Canyon (49,542 acres), Downieville (71 acres), Nevada City (16,819 acres) 

and Loyalton-Truckee (4,053 acres). 

Table 3.03-15 shows deer habitat acreage by deer habitat type for each of the primary deer herds 

(Blue Canyon, Downieville, Nevada City, and Loyalton-Truckee) occurring on NFS lands and non-NFS 

lands within the boundary of the Tahoe NF.

Table 3.03-15. Mule Deer Acreage of Habitat by type for each major deer herd within Tahoe NF boundary

Deer Herd Habitat Type Total Acres FS Acres

Blue Canyon Critical Summer 64,829 51,463

Critical Winter 12,115 11,196

Fawning 730 700

Holding 846 846

Summer 170,000 123,563

Winter 60,533 49,871

Downieville Critical Summer 60 22

Critical Winter 4,868 1,973

Fawning 0 0

Holding 0 0

Summer 247,422 185,859

Winter 56,679 38,541

Nevada City Critical Summer 60,162 37,853

Critical Winter 14,101 9,066

Fawning 8,118 4,107

Holding 2,455 572

Summer 110,000 60,651

Winter 37,071 19,309

Loyalton-Truckee Critical Summer 25,748 20,474

Critical Winter 8,524 5,876

Fawning 4,440 2,120

Holding 0 0

Summer 301,974 197,891

Winter 4,508 2,173
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200 – Tahoe National Forest

Many studies have been conducted on the interaction of road and trail-associated activities and mule 

deer, and have shown that road and trail-associated factors have the potential to impact mule deer 

populations directly and indirectly, including mortality from vehicle-collisions, modification of behavior 

(avoidance or flight), mortality from hunting and poaching, habitat fragmentation, edge effects of roads 

and trails, and others. Roads and trails can result in the disturbance or disruption of individuals in a deer 

population. Deer inhabiting areas near roads and trails may move away from the area when disturbed by 

humans. Several factors affect the degree to which trail and road associated human activities disrupt deer. 

This section will highlight some examples of the way in which roads and trails can affect individual deer 

and deer populations. Studies on both white-tailed deer and mule deer are included in the summaries.

Displacement or Avoidance: In general, mule deer will move away from, or flush, from an 

approaching person and will usually allow a person in or on a vehicle to get closer than a person on foot 

(Freddy et al. 1986, Wisdom et al. 2004). Wisdom et al. (2004) found that mule deer showed little 

measurable flight response to experimental OHV treatments but cautioned that deer may well be 

responding with fine-scale changes in habitat use (i.e. avoidance), rather than substantial increases in 

movement rates and flight responses. Several studies have found that mule deer avoid areas in proximity 

to roads. Deer avoid primary roads more than secondary or tertiary roads and also avoid roads more in 

open habitats as opposed to areas with vegetative or topographic cover (deVos et al. 2003). 

Various studies have shown that mule deer have displacement distances that vary between 200 and 

800 meters, depending upon the road type and traffic level, and the surrounding habitat (Perry and Overly 

1977, Rost and Bailey 1979, Johnson et al. 2000). One study found that if habitat was available away 

from a linear road or trail, then deer avoided the disturbance corridor (Jalkotzy et al. 1997). However, 

when no suitable deer habitat was available away from the road or trail, then deer used the habitat 

adjacent to the road or trail. Rost and Bailey (1979) reported that deer and elk in Colorado avoided roads, 

especially within 200 meters of a road. Perry and Overly (1977) reported that deer were displaced up to 

800 meters from roads. 

Main roads were found to reduce deer use up to 0.5 miles (800 m), whereas secondary and primitive 

roads reduced deer densities from between 200 to 400 meters in these studies. Additional variables such 

as the amount and frequency of traffic, and the spatial distribution of roads in relation to deer use, 

influence the degree of negative effects that roads have on deer use in forested habitats (Perry and Overly 

1977, Johnson et al. 2000, deVos et al. 2003). Where disturbance causes deer to avoid areas within 

preferred habitats, animals may be forced into less preferred or lower quality habitats. Such shifts, 

particularly if repeated, can result in adverse impacts to the energy balance of individual deer and 

ultimately can decrease population productivity, especially on winter ranges (deVos et al. 2003). 

Mortality: Hunting and Poaching: Greater human access can increase opportunities for hunting as 

well as poaching of deer. During the hunting season, deer may become more wary of humans, and 

disturbance to deer is greater when being hunted. In New York State, antlered deer were found to have 

longer flight distances than deer that were not hunted (Jalkotzky et al. 1997). Hunted deer populations 

tend to have stronger reactions to people on foot than motorized vehicles. This may be due to the fact the 

deer can detect a vehicle from greater distances rather than getting surprised by quieter humans on foot. 
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Tahoe National Forest – 201

Roads and trails can facilitate deer harvest success. A study using 143 radio-collared deer in Minnesota 

revealed that deer mortality during the hunting season was 2-4 times higher for deer that lived 0.2 km 

from a road versus those that were at greater than 0.3 km from a road. Major access routes radiating from 

urban centers into deer range provide increased opportunities for hunters.

Since hunting levels for deer are controlled through hunting zone quotas and tag limits established by 

the California Department of Fish and Game (CDFG), an increase in hunting opportunity or hunter 

success is unlikely to impact deer populations (deVos 2003). Hunting limits also take into account 

estimates of the amount of illegal kill and road kill occurring. Levels of illegal harvest are not presently 

described as a significant source of mortality for deer herds on the Tahoe NF (CDFG 2003, CDFG 1998). 

Thomas et al. (1979) used Perry and Overly’s data to develop a habitat effectiveness model based on 

road densities. The model indicated that a 20% loss in habitat effectiveness occurred when road densities 

were about 2 miles/mi2 for summer range habitat. At road densities of 6 miles/mi2

, habitat effectiveness 

declined by 50-95% depending on the type of road. 

One study found that all terrain vehicles altered deer feeding and use patterns, and these deer 

produced fewer young the following year (Yarmaloy 1988). An Arizona study using deer and elk decoys 

reported that illegal road hunting was widespread (Bancroft IN Watson 2005). Eleven of 19 archery elk 

and deer hunters and 41of 53 firearms hunters committed violations by attempting illegal take after 

observing a decoy from their vehicle.

Collisions: Vehicle collisions with deer can contribute considerably to direct deer mortality. Deer are 

probably the most frequently-killed large mammal along North America’s roads. The Insurance Institute 

for Highway Safety commissioned a study which estimated that more than 1.5 million deer/vehicle 

collisions occur annually, resulting in more than 29,000 human injuries and 150 deaths. Romin and 

Bissonette (1996), conservatively estimated that the U.S. national deer road kill in 1991 totaled at least 

500,000 deer. Deer road kills vary considerably by region and by season. In California, mule deer road 

kill along a 3 mile stretch of secondary highway was estimated at 3.7 and 4.8 per kilometer per year 

during spring and fall migrations, respectively (Jalkotzy et al. 1997). 

There are little to no data on deer road kills along Forest roads, however roads maintained at a higher 

standard for passenger vehicle (Maintenance Levels 3, 4, and 5), where vehicle speeds are greatest, have 

the most potential to contribute to deer-vehicle collisions. Deer-vehicle collisions on roads and trails 

which are maintained for high clearance vehicles (maintenance level 2 roads) are probably not 

appreciable in number due to the lower speeds and the amount of use received by these roads. 

Summary of trail and road associated impacts to mule deer:

• Mortality from hunting or trapping as facilitated by motorized road and trail access

• Increased illegal take of animals as facilitated by trails and roads

• Mortality or injury resulting from a motorized vehicle colliding with an animal

• Loss and resulting fragmentation of habitat due to the establishment of roads, trails, or networks, 

and associated human activities.
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202 – Tahoe National Forest

• Increased mortality of animals (euthanasia or shooting) due to increased contact with humans, as 

facilitated by road and trail access

• Interference with dispersal or other movements as posed by a road or trail itself or by human 

activities on or near roads, trails, or networks

• Spatial shifts in populations or individuals animals away from human activities on or near roads, 

trails, or networks

• Displacement of individual animals from a specific location that is being used for reproduction 

and rearing of young

• Increase in heart rate or stress hormones when near a road or trail or network of roads or trails.

Mule Deer: Environmental Consequences

Mule Deer: Indicators used to Measure Effects

Cross Country Travel: The prohibition of cross country travel is analyzed for its effects on the Blue 

Canyon, Downieville, Nevada City, and Loyalton-Truckee deer herds within each deer habitat type.

Additions to the NFTS (miles of motorized routes and Zone of Influence): To assess the potential 

direct and indirect impacts to deer from motorized route associated disturbance including noise, hunting, 

poaching, etc., the miles of motorized routes to be added to the NFTS were determined for each 

alternative by key deer habitat type (critical summer, fawning, winter, and critical winter) within each of 

the deer herds - Blue Canyon, Downieville, Nevada City, and Loyalton-Truckee. 

Critical winter range is considered to provide key habitat for deer during the winter months, and 

fawning habitat and critical summer range is expected to receive heavier deer use in the summer months. 

Determining the proportion of critical winter range and the proportion of critical fawning and summer 

range occurring within a Zone of Influence associated with roads or motorized trails, provides another 

measure of the effects of action alternatives upon these key deer types. 

Based upon the Rost and Bailey’s 1979 study in Colorado, which indicated that deer were displaced 

within a 200 meter distance of secondary roads, a distance of 200 meters was applied to represent the 

Zone of Influence related to motorized routes, since the majority of Tahoe NF roads and trails are likely 

most similar to those roads addressed in the Colorado study area. The use of a larger Zone of Influence

(i.e., 400 meters or 800 meters) could potentially exaggerate the effects of motorized routes, as the 

science of motorized route effects vary upon many factors. The proportion of each deer herd’s critical 

winter range habitat and critical summer range and fawning habitat occurring within this Zone of 

Influence was determined for each Alternative. Thresholds associated with this measure have not been 

established, but relative changes in habitat effectiveness can be evaluated and compared.

Changes to the NFTS: (Changes to Wet Weather Seasonal Restrictions, and Reopening 

Maintenance Level 1 Roads): Wet weather seasonal restrictions would apply to Alternatives 4, 5 and 6 

on native surfaced roads and motorized trails. The benefits to deer of these additional wet weather 

closures are analyzed for the alternatives. Reopening Maintenance Level 1 Roads that were previously 

closed to motorized use is analyzed for its potential for disturbance to the four major deer herds.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 203

Amendments to the Forest Plan: The 1990 Tahoe LRMP (Forest Plan) recognizes that the restriction 

of motorized vehicle access within certain deer habitat areas is important to deer, especially within key 

deer winter ranges. Seasonal restrictions for deer habitat as specified in the 1990 Tahoe Forest Plan and 

contained in existing Forest Orders would be continued. Table 3.03-16 displays the current seasonal 

restrictions specified in the Forest Plan. These seasonal restrictions apply to all native surface roads and 

motorized trails within the specified Management Areas.

Table 3.03-16. Tahoe Forest Plan Motor Vehicle Deer Seasonal Restrictions by Management Area (MA)

MA # MA Name Motor Vehicle Use Restriction Restricted Dates

11 Smithneck Prohibit wheeled vehicle travel off of designated routes in 

Bear and Jones Valleys for protection of winter deer range

None specified

12 Antelope Key Deer Winter Range and Migration Corridor – Closed to all 

motorized vehicle use. Designated routes only in summer 

season. Restricted period can be amended if weather 

conditions are such that deer are not on the winter range.

November 1 to May 1

23 Pendola Designated routes only, except closed south of the Long Point 

Road on key deer winter range. This restriction can be 

amended if weather conditions are such that deer are not on 

the winter range.

November 1 to May 1

24 Oregon Designated routes only, except closed November 1 to May 1 

in wildlife areas such as Plum Valley, Lohman Ridge, and 

Studhorse Canyon. This restriction can be amended if 

weather conditions are such that deer are not on the winter 

range.

November 1 to May 1

42 South Yuba Designated routes only, southwest of Bloody Run Creek and 

the Graniteville Road is closed November 1 to May 1 on deer 

winter range. Restricted period can be amended if weather 

conditions are such that deer are not on the winter range.

November 1 to May 1

59 Casa Loma Key Deer Winter Range - Designated routes only, except 

closed November 1 to May when deer are using the area.

November 1 to May 1

65 Chalk Key Deer Winter Range - Prohibit wheeled vehicle travel off of 

designated routes, trails, and limited off highway vehicle 

(OHV) use areas. This restriction can be amended if weather 

conditions are such that deer are not on the winter range in 

the Burlington Ridge and Greenhorn areas. 

November 1 to May 1 

84 Humbug-Sailor Key Deer Winter Range - Closed November 1 to May 1. This 

restriction can be amended if weather conditions are such that 

deer are not on the winter range.

November 1 to May 1

102 End of the World Designated routes only, except seasonal closure of deer 

holding area during the period September 15 to December 31 

annually. During winters with low preceipitation, this area will 

be closed. This restriction can be amended if weather 

conditions are such that deer are not on the holding area.

September 15 to 

December 31 

106 Big Oak Designated routes only in summer. Closed November 1 to 

May 1on key deer winter range. This restriction can be 

amended if weather conditions are such that deer are not on 

the winter range.

November 1 to May 1

108 Little Oak Designated routes only in summer. Closed November 1 to 

May 1 on key deer winter range. This restriction can be 

amended if weather conditions are such that deer are not on 

the winter range.

November 1 to May 1
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

204 – Tahoe National Forest

For Alternatives 2, 5 and 6, the Forest Plan would be amended to remove the November 1 to May 1 

seasonal closure in Management Area 84 (Humbug-Sailor) on key winter deer range. 

Mule Deer: Direct and Indirect Effects

Cross Country Travel: The prohibition of cross country travel was analyzed for the Blue Canyon, 

Downieville, Nevada City, and Loyalton-Truckee deer herds within each deer habitat type. The Tahoe NF 

LRMP has previously designated some areas within the deer herd boundaries closed to cross country 

travel which would continue for all alternatives. For each of the deer herds, under Alternative 1, cross 

country travel would continue (except for the existing LRMP closures), resulting in disturbance, 

disruption, avoidance, and abandonment of suitable habitats. Acreages where cross country travel is not 

currently prohibited for the four primary herds total 753,640 acres (Blue Canyon: 188,096 acres; 

Downieville: 226,324 acres; Nevada City: 114,739 acres; Loyalton-Truckee: 224,481 acres). For all 

action alternatives, for all herds, and in all seasonal ranges, the acres of proposed cross country motorized 

travel prohibitions would be equal to the amount of habitat available in each seasonal type, thus all action 

alternatives would substantially benefit all deer herds and reduce negative effects associated.

Additions to the NFTS: Table 3.03-17 displays the miles of proposed motorized route additions to 

the NFTS for the action alternatives, and the total miles of existing unauthorized routes for Alternative 1 

for each deer herd. Motorized route additions displays a way to compare alternatives to assess the direct 

and indirect impacts to deer from motorized routes where access for hunting and poaching, and 

disturbance and avoidance may occur. Key deer habitat within Critical Summer, Fawning, Critical Winter, 

and Winter Ranges are shown below. Alternative 1 poses the greatest risk to all deer herds on all deer 

seasonal ranges where over 450 miles of existing motorized unauthorized routes would continue to be 

used with continued cross-country travel. The action alternatives (except Alternative 3) range from adding 

5 to 12 miles of motorized routes, in ascending order (Alternatives 4, 7, 2, 6, and 5). Alternative 3 does 

not add any motorized routes, and therefore, does not add additional motorized impacts within key 

seasonal ranges for any of the major deer herds on the Tahoe NF.

Blue Canyon Deer Herd: Alternative 1 poses the greatest risk to the Blue Canyon Deer Herd on both 

critical summer and critical winter/winter ranges. The action alternatives (except Alternative 3) add 4 to 6 

miles (Alternative 4 – least to Alternative 5 – most) of motorized routes within critical summer and 

critical winter/winter ranges. Within Critical Summer Range, implementing Alternative 1, with continued 

cross-country travel and associated use of unauthorized routes, would have motorized route miles that 

exceed all the action alternatives by about 50 miles. Within winter and critical winter ranges, Alternative 1 

exceeds action alternatives (Alternatives 2, 3, 4, 5, 6, 7) by least 130 miles.

Downieville Deer Herd: Alternative 1 poses the greatest risk to the Downieville Deer Herd on both 

critical winter and winter ranges where resources may be scarce and deer may be stressed during the 

winter months. For the Downieville Deer Herd, only about 60 acres of critical summer and no fawning 

areas fall within the boundaries of the Tahoe NF. Within critical winter range, Alternative 1 has 17 

motorized route miles, and the all the action alternatives have 14 miles of motorized routes each. Within 

winter range, Alternative 1 has the highest number of motorized route miles (76.3 miles), where direct 
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Tahoe National Forest – 205

and indirect disturbance associated with motorized routes could occur when deer are stressed during the 

winter. Alternatives 2, 4, 5, 6, and 7 each adds 0.2 miles of motorized route miles within winter range,

Nevada City Deer Herd: Alternative 1 poses the greatest risk to the Nevada City Deer Herd on all 

key deer habitat types - critical summer, critical winter, and winter habitats when deer are most vulnerable 

to disturbance. Motorized miles in Alternative 1 exceeds the action alternatives in all key seasonal ranges 

by at least 138 miles, with Alternative 5 having the most motorized additions (5 miles) followed by 

Alternatives 2, 6, 7, 4.

When comparing critical summer and fawning habitat for the Nevada City Deer Herd, Alternative 1 

exceeds the action alternatives by at least 37 miles (in descending order - Alternatives 6, 5, 2, 7, 4, and 3). 

For critical winter habitat and winter ranges, Alternative 1 exceeds the action alternatives by 100 miles.

Alternative 5 adds 3 miles of motorized routes, followed by Alternatives 2 and 6, with 1 mile and 0.1 mile 

added, respectively within key winter ranges. The remaining alternatives would not add motorized routes 

in key winter ranges.

Loyalton-Truckee Deer Herd: Motorized route miles for the Loyalton-Truckee Deer Herd are 

greatest under Alternative 1, where motorized route miles exceed all the action alternatives by at least 50 

miles within all seasonal ranges (Table 3.03-17). With the exception Alternative 6 where 1 mile of 

motorized route is added within critical summer habitat, the remaining action alternatives do not add any 

motorized miles to the NFTS within any seasonal ranges for the Loyalton-Truckee Deer Herd.

Table 3.03-17. Miles of Motorized Route Additions on within deer herd winter ranges, critical winter ranges, 

critical summer, and fawning areas on the Tahoe NF

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Blue Canyon Deer Herd Critical Summer 51.0 1.3 0 0.2 1.5 1.5 0.9

Fawning 0.1 0 0 0 0 0 0

Critical Winter 22.6 0 0 0 0 0 0

Winter 112.7 4.6 0 4.1 4.9 4.8 4.5

All Seasonal Ranges 186.4 5.9 0 4.3 6.4 6.3 5.4

Downieville Deer Herd Critical Summer 0.1 0 0 0 0 0 0

Fawning 0 0 0 0 0 0 0

Critical Winter 1.7 0 0 0 0 0 0

Winter 74.5 0.2 0 0.2 0.2 0.2 0

All Seasonal Ranges 76.3 0.2 0 0.2 0.2 0.2 0
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206 – Tahoe National Forest

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Nevada City Deer Herd Critical Summer 30.3 1.7 0 0.5 1.7 2.3 0.8

Fawning 9.5 0.3 0 0 0.3 0.3 0.2

Critical Winter 40.2 0 0 0 0 0 0

Winter 62.9 1.0 0 0 3 0.1 0

All Seasonal Ranges 142.9 3.0 0 0.5 5.2 2.9 1.0

Loyalton-Truckee Deer 

Herd

Critical Summer 39.0 0 0 0 0 1.1 0

Fawning 3.4 0 0 0 0 0 0

Critical Winter 6.0 0 0 0 0 0 0

Winter 3.6 0 0 0 0 0 0

All Seasonal Ranges 52.0 0 0 0 0 1.1 0

Total for all herds within all seasonal ranges 457.6 9.1 0 5 11.6 10.3 6.4

* Alternative 1 includes miles of unauthorized routes that would remain with continued use 

Zone of Influence: As stated above, deer were found to respond to disturbance associated with

secondary motorized roads and trails within a 200-meter distance. Analyzing for these variables can be 

complex because deer may respond differently, depending on the type of motorized route and the type of 

surrounding vegetation, the intensity of animal use, and the degree to which motorized activities overlap 

with deer use. The action alternatives consider the addition of motorized routes, and therefore, a Zone of 

Influence within 200 meters of motorized route additions was used by to compare differences in the direct 

and indirect impacts between alternatives for each deer herd, within key deer ranges (Table 3.03-18). 

Although major roads (i.e., paved and surfaced roads used by passenger vehicles which receive higher use 

levels and rates of speed, including county roads, state highways, etc.) may have a greater influence on 

deer than secondary motorized routes, a 200-meter Zone of Influence was used to analyze all existing 

motorized routes consistently because using a greater Zone of Influence may result in excessive overlap 

in habitat when considering all motorized routes, and therefore, overstate the effects of motorized routes.

Areas that are less influenced by motorized routes are considered “security habitat,” whereas, areas 

influenced by motorized routes are considered “zones of influence” where deer are less secure. For 

Alternative comparison purposes, a simple ranking system, such as the one developed by Gaines et al. 

(2003), is used. For this purpose, less than 25 percent of key habitat affected was ranked as a low level of 

road or trail influence, 25 to 50 percent of key habitat affected was ranked as a moderate level of 

influence, and greater than 50 percent of key habitat affected was ranked as a high level of influence. 

Using this ranking system, Alternative 1 results in a “high” level of motorized route influence on each 

deer herd’s critical summer and winter ranges combined, where the effectiveness of critical deer range 

habitat could be reduced. All the action alternatives result in a “low” influence to key summer and winter 

ranges from the addition of routes, and therefore considerably improves deer habitat security or 

effectiveness compared to Alternative 1. The sections below describe how the alternatives affect key deer 

seasonal habitats from the addition of motorized routes.

Blue Canyon Deer Herd: Alternative 1 poses the greatest risk to the Blue Canyon Deer Herd from 

reduced habitat effectiveness from potential disturbance or avoidance behavior as a result of factors 
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Tahoe National Forest – 207

associated with cross country travel, including continued use of unauthorized routes. Under Alternative 1, 

approximately 20% of key winter deer ranges are influenced by continued use of existing unauthorized 

routes. Unauthorized routes influence key summer ranges of the Blue Canyon herd at a relatively low 

level (2% fawning, 11% critical summer). All the action alternatives result in a low influence (0-1%) on 

key deer ranges from proposed motorized additions. Motorized route additions for Alternative 5 

influences 3% of critical winter ranges compared to the other action alternatives.

Downieville Deer Herd: The Downieville Deer Herd is moderately affected overall by Alternative 1,

where 42% of critical summer ranges, 7% critical winter, and 16% winter ranges are within a 200-meter 

Zone of Influence of existing motorized unauthorized routes. Alternatives 2, 3, 4, 6 and 7 do not directly 

or indirectly affect key deer habitats. Alternative 5 contributes to a low amount of key habitats affected by 

adding motorized routes within a 200-meter Zone of Influence where, on average, 1% of key deer habitats 

are affected.

Nevada City Deer Herd: Alternative 1 poses the greatest risk where a “moderate” amount of key 

winter deer habitat (27%) is influenced by continued use on unauthorized routes associated with cross 

country travel within the Nevada City Deer Herd resulting in a moderate reduction of habitat 

effectiveness on winter ranges when deer are stressed and resources may be low. Critical summer and 

fawning habitat is influenced by unauthorized routes by 9% and 15%, respectively, which individually 

contributes to a relatively low level of potential disturbance by motorized use when deer are on key 

summer ranges. The action alternatives all result in a “low” amount of key deer habitat (0-2%) being 

influenced by motorized routes added to the NFTS. 

Loyalton-Truckee Deer Herd: All the alternatives result in a “low” influence on key deer habitats 

within the Loyalton-Truckee Deer herd, with Alternative 1 resulting in the greatest amount of key deer 

habitats influenced by disturbance potential from continued use of unauthorized routes associated with 

cross country travel. Alternative 1 directly and indirectly affects between 13 to 19% key summer habitats 

and 11% key winter ranges. The remaining alternatives affect between 0 to 2% of key deer summer and 

winter habitats, and therefore would not result in a measurable change in habitat effectiveness.

Table 3.03-18. Percent of Key Deer Ranges within a 200-meter “Zone of Influence” of Motorized Route 

Additions by Herd

Range Type Acres Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Blue Canyon Deer Herd Critical Summer 64,829 11% <1% 0% <1% 1% 1% <1%

Fawning 730 2% 0% 0% 0% 0% 0% 0%

Critical Winter 12,115 20% 0% 0% 0% 3% 0% 0%

Winter 60,533 21% 1% 0% 1% 1% 1% 1%

Downieville Deer Herd Critical Summer 60 42% 0% 0% 0% 0% 0% 0%

Fawning 0 0% 0% 0% 0% 0% 0% 0%

Critical Winter 4,868 7% 0% 0% 0% 0% 0% 0%

Winter 56,679 16% 0% 0% 0% 0% 0% 0%
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208 – Tahoe National Forest

Range Type Acres Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Nevada City Deer Herd Critical Summer 60,162 9% 1% 0% <1% 1% 2% <1%

Fawning 8,118 15% 1% 0% 0% 1% 1% 1%

Critical Winter 14,101 27% 0% 0% 0% 0% 0% 0%

Winter 37,071 17% 0% 0% 0% 2% 0% 0%

Loyalton-Truckee Deer 

Herd

Critical Summer 25,748 19% 0% 0% 0% 0% 2% 0%

Fawning 4,440 13% 0% 0% 0% 0% 0% 0%

Critical Winter 8,524 11% 0% 0% 0% 0% 0% 0%

Winter 4,508 11% 0% 0% 0% 0% 1% 0%

*Alternative 1 includes unauthorized routes associated with continued cross country travel.

Changes to the NFTS (Wet Weather Seasonal Restrictions, Reopening Maintenance Level 1 

Roads): Wet Weather Seasonal Restrictions: Wet weather seasonal restrictions of native surface 

motorized roads and trails are analyzed for the action alternatives. Alternatives 4, 5, and 6 provide 

additional wet weather seasonal restrictions, which may benefit deer that may potentially use areas that 

are not currently under existing Forest Plan deer seasonal restrictions. In areas outside current Forest Plan 

deer seasonally restricted areas, the wet weather seasonal closures would provide an additional 3 months 

wet weather closure (3 months for the Burlington Ridge and Greenhorn area) and would reduce the 

effects of motorized vehicles upon deer using these areas, as compared to Alternatives 1, 2, 3, and 7, 

which have no wet weather seasonal closures. Alternatives 4, 5, and 6 could result in shorter or longer wet 

weather closure periods, but this would vary annually depending upon rainfall and soil conditions.

Reopened Maintenance Level 1 Roads: Reopening Maintenance Level 1 roads (ML 1) has the 

potential to introduce disturbance to deer from activities associated with motorized vehicles on key deer 

habitat where deer are most vulnerable. Miles of reopened ML 1 roads and the Zone of Influence within 

200 meters were determined for each of the deer herds.

Reopened ML 1 Roads: Alternative 5 potentially affects the most seasonal deer ranges across the 

Tahoe NF, where approximately 16 miles of ML 1 roads would be reopened to motorized use and could 

increase disturbance to deer on key summer and winter ranges (Table 3.03-19). Alternatives 2 and 6 

would reopen a total of about 1 mile of ML 1 roads, for about 1⁄2 mile each within winter range of the 

Downieville deer herd and critical summer range of the Loyalton-Truckee deer herd. Alternative 4 would 

reopen a total 1⁄2 mile ML 1 road within Blue Canyon critical summer and Nevada City Deer Herd key 

winter range. The remaining alternatives do not reopen ML 1 roads, and therefore would not increase 

disturbance to deer on key seasonal habitats.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 209

Table 3.03-19. Miles of Reopened Maintenance Level 1 Roads within Key Deer Habitats

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Blue Canyon Deer Herd Critical Summer 0 0 0 0.3 3.7 0 0

Fawning 0 0 0 0 0.1 0 0

Critical Winter 0 0 0 0 3.9 0 0

Winter 0 0 0 0 2.7 0 0

Downieville Deer Herd Critical Summer 0 0 0 0 0 0 0

Fawning 0 0 0 0 0 0 0

Critical Winter 0 0 0 0 0 0 0

Winter 0 0.5 0 0 0.5 0.5 0

Nevada City Deer Herd Critical Summer 0 0 0 0 0 0 0

Fawning 0 0 0 0 0 0 0

Critical Winter 0 0 0 0.1 2 0 0

Winter 0 0 0 0.1 2.6 0 0

Loyalton-Truckee Deer Herd Critical Summer 0 0.6 0 0 0.6 0.6 0

Fawning 0 0 0 0 0 0 0

Critical Winter 0 0 0 0 0 0 0

Winter 0 0 0 0 0 0 0

Total Miles Reopened ML 1 Roads 0 1.1 0 0.5 16.1 1.1 0

Zone of Influence: Table 3.03-20 displays the percent of key deer ranges within a 200-meter Zone of 

Influence of reopened ML 1 roads by alternative for each of the deer herds. Alternative 5 is the only 

alternative that impacts any of the deer herds from the reopening of ML 1 roads, with the exception of 

Alternative 2 which only affects less than 1% of critical summer habitat of the Loyalton-Truckee herd.

This minor amount of effect from Alternative 2 should not pose a measurable risk to the LoyaltonTruckee herd. The Downieville Deer Herd has no impacts from any alternative

Although Alternative 5 would potentially impact three of the four major deer herds from the 

reopening of ML 1 roads, implementing Alternative 5 would only influence about 1-2% of any given 

habitat type. At the herd scale, this proportion of impact should not pose a concern to either the Blue 

Canyon, Nevada City, or the Loyalton-Truckee herds, and therefore overall habitat security would not be 

greatly compromised from reopening ML 1 roads. However, there may be localized impacts which may 

increase disturbance to individual deer. These impacts would vary depending on the amount of 

disturbance already occurring from existing roads and activities. Areas where checkerboard ownership 

patterns have already highly fragmented deer winter range, such as the Nevada City and the Blue Canyon 

herds, deer could experience even more disturbance and harassment.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

210 – Tahoe National Forest

Table 3.03-20. Percent of Key Deer Ranges within a 200-meter “Zone of Influence” of Reopened Maintenance 

Level 1 Roads by Herd

Range Type Acres Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Blue Canyon Deer Herd Critical Summer 64,829 0% 0% 0% 0% 1% 0% 0%

Fawning 730 0% 0% 0% 0% 2% 0% 0%

Critical Winter 12,115 0% 0% 0% 0% 0% 0% 0%

Winter 60,533 0% 0% 0% 0% 1% 0% 0%

Downieville Deer Herd Critical Summer 60 0% 0% 0% 0% 0% 0% 0%

Fawning 0 0% 0% 0% 0% 0% 0% 0%

Critical Winter 4,868 0% 0% 0% 0% 0% 0% 0%

Winter 56,679 0% 0% 0% 0% 0% 0% 0%

Nevada City Deer Herd Critical Summer 60,162 0% 0% 0% 0% 0% 0% 0%

Fawning 8,118 0% 0% 0% 0% 0% 0% 0%

Critical Winter 14,101 0% 0% 0% 0% 1% 0% 0%

Winter 37,071 0% 0% 0% 0% 1% 0% 0%

Loyalton-Truckee Deer Herd Critical Summer 25,748 0% <1% 0% 0% <1% 0% 0%

Fawning 4,440 0% 0% 0% 0% 0% 0% 0%

Critical Winter 8,524 0% 0% 0% 0% 0% 0% 0%

Winter 4,508 0% 0% 0% 0% 0% 0% 0%

Amendments to the Forest Plan

Key Deer Winter Range for the Blue Canyon Deer Herd: Existing Forest Plan direction for the 

Humbug-Sailor Management Area (#84) includes the following: “Off-Highway Vehicle Restrictions - On 

key winter deer winter range, closed November 1 to May 1. This restriction can be amended if weather 

conditions are such that deer are not on the winter range.”

Winter range (winter and critical winter) for the Blue Canyon Deer Herd encompasses a large area 

(72, 648 acres). Within Blue Canyon Deer Herd winter range, the Forest Plan identified a total of 16,108 

acres as key deer winter range located in two separate locations. One key winter range area lies in the 

northwest portion of the Blue Canyon deer winter range and falls within several management areas, 

including Casa Loma, North Fork, American, Sugar Pine Point, Macy, Sugar Pine and Humbug-Sailor.

The other key winter range area lies near the southern edge of the winter range and overlaps with the Big 

Oak, Little Oak and Mosquito management areas (Figure 3.03-1). There are currently 79.2 miles of roads 

and motorized trails within key winter range of the Blue Canyon Deer Herd (See Figure 3.03-1).

Alternatives 1, 3, 4, and 7 do not proposed to amend the Forest Plan deer restriction within the HumbugSailor MA, and therefore would have no affect to deer.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 211

Figure 3.03-1. Blue Canyon Deer Herd Key Winter Range – Existing Motorized Routes
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

212 – Tahoe National Forest

Alternatives 2, 5, and 6 propose to amend the Forest Plan by changing the motorized season of use of 

May1 to Nov 1 within the Humbug-Sailor Management Area (#84), thereby reducing the seasonal 

restriction period by a total of 2-3 months along 8.6 miles of existing NFTS (26 Road) as shown in Tables 

3.03-21 and 22. This would result in potentially affecting 1,228 acres (200 meters Zone of Influence) or 

7.6% of total key deer winter range of the Blue Canyon Deer Herd (Table 3.03-21) (Figure 3.03-2) 

located at the southern edge of the key deer winter range in the Humbug-Sailor area where deer may 

potentially be temporarily disturbed from motorized related noise or displaced.

In addition, alternatives 4, 5, and 6 would result in 3.6 - 6.8 fewer miles that are currently open year 

round to having a wet weather seasonal restriction (Table 3.03-22). Ultimately, the Forest Plan 

Amendment to alter the current deer seasonal restriction under Alternatives 2, 5, and 6 is not expected to 

pose a significant risk to the overall condition and trend of the Blue Canyon deer herd especially since 

annual weather conditions are likely to have a greater influence on deer herd numbers in the area 

compared to motorized use along existing roads during the months of November, December, and April.

Furthermore, motorized use in this area is relatively low during these months, especially in April when the 

area may still be under snow. Therefore, motorized vehicle and deer interactions are likely to be 

negligible since motorized use and deer presence along the 26 Road are likely to be minimal, and 

therefore would have little effect on the Blue Canyon Deer Herd.

Table 3.03-21. Blue Canyon Deer Herd - Key Deer Winter Range Summary for Alternatives 2, 5, and 6

Description Status

Total Acres Key Deer Winter Range 16,108 acres

Seasonal Restriction within Humbug-Sailor MA Alts 2 & 6 reduced by 3 months, Alt 5 reduced by 2 months

Miles Affected Within Key Deer Winter Range Affected 8.6 miles

Acres Key Deer Winter Range Affected (200 meter ZOI) 1,228 acres

Percent of Key Deer Winter Range Affected 7.6%

Beneficial Effects to Key Deer Winter Range from Other Actions:

• Prohibition of Cross Country Travel on 16,108 acres Key Deer Winter Range (including 28 miles 

of unauthorized routes).

• Wet Weather Restrictions within Key Deer Winter Range on an additional 3.7 miles (615 ac or 

3.8% of key winter range) that were previously open all year.

Table 3.03-22. Motorized Season of Use within Blue Canyon Herd Key Deer Winter Range

Miles Motorized 

NFTS Roads 

and Trails

Season Of Use Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Year round 15.6 15.6 15.6 12.0 8.8 12.0 15.6

May 1 - Nov 1 (LMP Deer Key Winter Range) 29.1 20.5 29.1 29.1 25.1 20.5 29.1

May 1 - Dec 31 (Wet Weather) 0 0 0 3.6 15.5 0 0

Apr 1 - Dec 31 (Wet Weather) 0 8.7 0 0 0 12.3 0

Miles Unauthorized Routes 28.0 0 0 0 0 0 0

Total 72.8 44.8 44.8 44.8 49.4 44.8 44.8
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 213

Figure 3.03-2. Blue Canyon Deer Herd - LMP Amendment Proposed Change in Season of Use within the 

Humbug-Sailor Management Area
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

214 – Tahoe National Forest

Blue Canyon Deer Herd Population Trend

The deer population in Zone D-4 is considered stable to slightly increasing for the period from 1999 to 

2008 (Table 3.03-23 and Figure 3.03-3). The Blue Canyon deer herd on the Tahoe NF falls within the 

larger Deer Hunt Zone D-4 located in portions of Colusa, Nevada, Placer, Sacramento, Sutter, Yolo and 

Yuba counties. Short-term fluctuations in deer populations are usually attributed to weather events that 

affect forage production. Table 3.03-23 displays population numbers from 1999 to 2008 from the 

California Dept. of Fish and Game that are created using a model utilizing harvest data. A major 

assumption of this model is a correlation between hunter success and population size. Factors that might 

affect hunter success, such as weather, are not accounted for in the model. Hence, the year to year 

variation is probably smaller than the population numbers show.

Table 3.03-23. Zone D-4 Deer Population Numbers 1999-2008

Year Population Numbers

1999 3,340

2000 3,273

2001 6,140

2002 5,000

2003 5,800

2004 3,670

2005 4,870

2006 2,240

2007 4,830

2008 5,590
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 215

Figure 3.03-3. Blue Canyon Deer Herd Population Trend within the Deer Hunt Zone D-4 

Due to the complexity of factors that affect deer population trends within the Deer Hunt Zone D-4 (i.e., 

urbanization, hunting, long-term habitat condition, annual weather variation, etc.), it is not likely that a 

shift in changing the season of motorized use under alternatives 5 and 6 by 2-3 months and for Alternative 

2 by 6 months, affecting less than 8% of key winter range in the local Humbug-Sailor area would 

significantly affect deer such that population numbers within D-4 would change. In addition, the overall 

effects of the prohibition of cross country travel on 16,108 acres of key winter range, including on 

unauthorized routes and imposing additional motorized wet weather seasonal restrictions within key winter 

range and surrounding areas would provide an overall net benefit by reducing motorized disturbance 

within the Blue Canyon Deer Herd under all the action alternatives, and therefore, would meet the intent of 

Forest Plan S&G to “Limit vehicle access on key deer winter ranges when deer are present.”

Mule Deer: Summary of Direct and Indirect Effects

Table 3.03-24 summarizes the overall net effect to the mule deer from the proposed actions from cross 

country travel, motorized route additions to NFTS, establishment of motorized “Open Areas,” changes to 

the NFTS (Change in season of use, change in class of vehicles, reopening of Maintenance Level 1

roads), and amendments to the Forest Plan by removing motorized seasonal restrictions in the HumbugSailor Management Area 84.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

216 – Tahoe National Forest

Table 3.03-24. Mule Deer - Summary of Overall Net Direct and Indirect Effects*

Indicator Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres of Habitat Where Travel is 

Prohibited

70,485 751,981 751,981 751,981 751,981 751,981 751,981

Miles of user created and temporary 

roads where cross country travel 

would continue

458 0 0 0 0 0 0

Motorized Route Additions to NFTS

Trend of Effect Negative (most 

impactive 

alternative)

Negative (3rd 

most impactive 

alternative)

No Effect Negative (shares 

5th most impactive 

alternative with 7)

Negative (2nd

most impactive 

alternative)

Negative (4th

most impactive 

alternative)

Negative (shares 

5th most 

impactive 

alternative with 4)

Miles of motorized route additions 0 9 0 5 12 10 6

Establishment of Motorized “Open 

Areas”

No Effect Increased 

Localized 

Disturbance 

Potential at 

Greenhorn (60 

ac) and at Boca, 

Prosser and 

Stampede 

Reservoirs 

(2589 acres)

No Effect No Effect No Effect Increased 

Localized 

Disturbance 

Potential at Boca, 

Prosser and 

Stampede 

Reservoirs (244 

ac)

No Effect

Changes 

to the 

NFTS

Change in Season of Use 

(wet weather restrictions)

No Effect No Effect No Effect Reduces 

disturbance when 

deer are on winter 

and spring ranges

Reduces 

disturbance when 

deer are on winter 

and spring ranges

Reduces 

disturbance when 

deer are on 

winter and spring 

ranges

No Effect

Change in Class of 

Vehicles

No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Miles of Maintenance Level 1 (ML 1) Roads Reopened

Trend of Effect No Effect Negative (2nd

most impactive 

shared with Alt 

6)

No Effect Negative (3rd

most impactive)

Negative (most 

impactive)

Negative (2nd most 

impactive shared 

with Alt 2)

No Effect

Miles of ML 1 Roads 

Reopened

0 1 0 0.5 16 1 0
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 217

Indicator Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Amendments to the Forest Plan Existing deer 

seasonal 

restrictions (Nov 1 

to May 

Removes

Humbug Sailor 

MA 84 deer 

seasonal 

restrictions

Existing deer 

seasonal restrictions 

(Nov 1 to May)

Existing deer 

seasonal

restrictions (Nov 

1 to May

Removes 

Humbug Sailor 

MA 84 deer 

seasonal 

restrictions, 

however wet 

weather seasonal 

restrictions apply 

(Jan 1 to April 30)

Removes 

Humbug Sailor 

MA 84 deer 

seasonal 

restrictions, 

however wet 

weather seasonal 

restrictions apply 

(Jan 1 to April 30)

Removes

Humbug Sailor 

MA 84 deer 

seasonal 

restrictions

Overall Net Effect of Proposed 

Actions (compared to Alternative 1)

Negative effects 

from unauthorized 

cross country 

travel; fewer 

controls on winter 

and spring ranges. 

Beneficial effect 

from prohibited 

cross country 

travel;localized 

disturbance on 

winter ranges in 

Humbug Sailor 

MA 84; and 

minor negative 

effects from 

route additions 

and reopened 

ML 1 roads; 

overall reduces 

habitat 

fragmentation.

Beneficial effect from 

prohibited cross 

country travel.

Beneficial effect 

from prohibited 

cross country 

travel; reduced 

disturbance on 

winter and 

spring ranges; 

although minor 

negative effects 

from route 

additions and 

reopened ML 1 

roads; overall 

reduces habitat 

fragmentation.

Beneficial effect 

from prohibited 

cross country 

travel; reduced 

disturbance on 

winter and spring 

ranges; localized 

disturbance on 

winter ranges in 

Humbug Sailor 

MA 84; and minor 

negative effects 

from route 

additions and 

reopened ML 1 

roads; overall 

reduces habitat 

fragmentation.

Beneficial effect 

from prohibited 

cross country 

travel; reduced 

disturbance on 

winter and spring 

ranges; localized 

disturbance on 

winter ranges in 

Humbug Sailor 

MA 84 and minor 

negative effects 

from route 

additions and 

reopened ML 1 

roads; overall

reduces habitat 

fragmentation.

Beneficial effect 

from prohibited 

cross country 

travel; although 

minor negative 

effects from route 

additions; overall 

reduces habitat 

fragmentation.

Mule Deer: *Also see summary of direct and indirect effects to oak associated species
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

218 – Tahoe National Forest

Cumulative Effects

Cumulative Effects from Motorized Routes: The geographic boundary for assessing cumulative effects 

of motorized and non-motorized routes includes all lands within the Tahoe NF. The Tahoe NF 

encompasses the majority of the land base within the Blue Canyon, Nevada City, Downieville, and 

Loyalton-Truckee deer herds. The Tahoe NF is sufficiently large enough to assess cumulative effects of 

motorized and non-motorized routes since the Tahoe ranges from low elevation to high elevation and 

includes an array of habitat types used by migratory mule deer. It also covers a variety of deer habitat 

types including critical summer, summer, fawning, critical winter, winter, holding areas, and migration 

corridors. The timeframe for assessing past cumulative effects from motorized routes to mule deer takes 

into consideration the aggregate approach of the existing condition. The current condition and current use 

of motorized routes is the result of past actions. The timeframe for considering foreseeable future actions 

is approximately 20 years out. Cumulative effects to deer from motorized routes is assessed by using 

indicators of cumulative route density across the Tahoe NF, cumulative motorized route miles, and the 

Zone of Influence of all motorized routes. 

Motorized Route Density: Road density has traditionally been used as an indicator for deer habitat 

effectiveness models (Perry and Overly 1977, Thomas, et al. 1979). These models indicate that as road 

density increases, deer use declines (Thomas et al. 1979, Witmer et al 1985). Factors such as hunting 

pressure, poaching, and other human disturbances are also likely to relate to road densities. Critical winter 

range, critical summer range, and fawning habitats represent key habitats for deer where heavier use and 

higher quality habitats for wintering and summer use are expected to occur. The average motorized route 

densities within critical winter range, critical summer range, and fawning habitat for each deer herd 

within the Tahoe NF was determined.

Table 3.03-25 shows the average road and trail densities within deer herd ranges under each 

Alternative (calculated by dividing the total road or trail mileage on NFS lands in deer ranges by the 

square miles of NFS lands in deer ranges).

For all major deer herds occurring within the boundaries of the Tahoe NF, Alternative 1 would have 

the greatest cumulative route densities compared to all the action alternatives within essential summer 

(fawning and critical summer) and winter (critical winter and winter) ranges. Alternative 5 would have 

slightly greater route densities than all the remaining action alternatives. Within critical summer and 

fawning areas, Alternative 1 poses a somewhat higher risk to all deer herds on the Tahoe NF and may 

therefore pose a greater risk in the ability for these deer herds to successfully reproduce and rear fawns, as 

compared to all the action alternatives. The action alternatives are similar in their motorized route 

densities and therefore, impacts to the Tahoe deer herds within critical summer or critical winter ranges do 

not vary amongst the action alternatives. Alternative 1 also has the greatest direct and indirect effects to 

winter ranges, especially on the west side of the Forest, where Alternative 1 motorized route densities 

exceed the action alternatives by over 1 mile/square mile in some instances, where habitat effectiveness 

would be reduced.

Blue Canyon Deer Herd: Implementing Alternative 1 would result in route densities that exceed 

route densities for all the action alternatives by over 1 mile per square mile within winter range for the 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 219

Blue Canyon Deer Herd, and would be approximately the same within critical winter range. Within 

critical summer ranges, Alternative 1 exceeds route densities for the action alternatives by 0.5 miles/mile2.

For all alternatives, route densities within fawning habitat are approximately 2 miles/mile2

, whereas 

Alternative 1 exceeds action alternative route densities by about 1 mile/mile2.

Downieville Deer Herd: For the Downieville Deer Herd, only about 60 acres of critical summer 

range falls within the boundaries of the Tahoe NF. No motorized route miles fall within fawning habitat 

for this deer herd. In critical summer habitat, Alternative 1 has route densities of 3 miles/miles2 or 0.3 

miles/square miles higher than all other alternatives. Within critical winter range, Alternative 1 route 

densities are slightly higher than all the action Alternatives (Alternative 1 3 mi/mi2

, action alternatives 2.8 

mi/mi2 Within winter range, Alternative 1 has route densities of 3.5 miles/square mile, which exceed route 

densities in all the action alternatives by at least 0.8 mile/square mile.

Nevada City Deer Herd: Alternative 1 route densities exceed all the action alternative route densities 

by about 1/2 mile/square mile within critical summer range, and by nearly 1 mile/square mile within 

fawning habitat, where increased disturbance could reduce reproductive productivity. Within winter 

range, Alternative 1 route densities exceed the action alternatives by nearly a mile/square mile and 

slightly less than that compared to Alternative 5. Critical winter habitat for the action alternatives range 

from 2.6 to 2.7 miles/square mile, whereas Alternative 1 has route densities at nearly 4 1⁄2 miles/square 

mile, and poses a considerable increased risk of disturbance to deer while on critical winter ranges when 

motorized vehicles are present.

Loyalton-Truckee Deer Herd: Route densities for the Loyalton-Truckee deer herd are greatest under 

Alternative 1, where route densities exceed all the action alternatives approximately 1⁄2 to 1 mile/square 

mile within each of critical summer, fawning, critical winter, and winter ranges. There are no differences 

in route densities for the action alternatives within all seasonal ranges for the Loyalton-Truckee deer herd.

Table 3.03-25. Average route densities (miles/square mile) on NFS lands within deer herd winter ranges, 

critical winter ranges, critical summer, and fawning areas on the Tahoe NF

Range Type Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Blue Canyon 

Deer Herd

Critical Summer 2.1 1.6 1.6 1.6 1.6 1.6 1.6

Fawning 0.1 0 0 0 0.1 0 0

Critical Winter 3.4 2.1 2.1 2.1 2.3 2.1 2.1

Winter 4.6 3.2 3.2 3.2 3.3 3.2 3.2

Downieville

Deer Herd

Critical Summer 0.6 0 0 0 0 0 0

Fawning 0.0 0.0 0.0 0.0 0.0 0.0 0.0

Critical Winter 3.0 2.8 2.8 2.8 2.8 2.8 2.8

Winter 3.5 2.7 2.7 2.7 2.7 2.7 2.7
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220 – Tahoe National Forest

Range Type Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Nevada City 

Deer Herd

Critical Summer 2.5 2.1 2.0 2.0 2.1 2.1 2.1

Fawning 3.9 3.1 3.1 3.1 3.1 3.1 3.1

Critical Winter 4.4 2.6 2.6 2.6 2.7 2.6 2.6

Winter 4.3 3.2 3.2 3.2 3.3 3.2 3.2

Loyalton-Truckee 

Deer Herd

Critical Summer 2.9 2.0 2.0 2.0 2.0 2.0 2.0

Fawning 4.7 4.1 4.1 4.1 4.1 4.1 4.1

Critical Winter 1.8 1.2 1.2 1.2 1.2 1.2 1.2

Winter 2.7 2.2 2.2 2.2 2.2 2.2 2.2

*Alternative 1 includes motorized unauthorized routes associated with continued cross country travel.

Cumulative Motorized Route Miles: The total cumulative motorized route miles (existing routes on 

the Tahoe NFTS, existing private routes, proposed motorized additions, and reopened of Maintenance 

Level 1 roads) are shown in Table 3.03-26 and described below for each deer herd.

Blue Canyon Deer Herd: Alternative 1 poses the greatest risk to the Blue Canyon Deer Herd on both 

critical summer and critical winter/winter ranges, followed next by Alternative 5. Within Critical Summer 

Range, implementing Alternative 1 would have motorized route miles that exceed Alternative 5 by about 

18 miles, and exceed Alternatives 2, 3, 4, 6, by nearly 40 miles for the Blue Canyon Deer Herd. The miles 

of motorized routes within fawning habitat for the Blue Canyon herd is minor. 

Within critical winter ranges, Alternatives 1 has the most motorized route miles at 65 miles, followed 

by Alternative 5 with 50 miles. Approximately miles of motorized routes in critical winter range for the 

remaining action alternatives. A similar pattern emerges for winter range. 

Downieville Deer Herd: Alternative 1 poses the greatest risk to the Downieville Deer Herd on both 

critical winter and winter ranges where resources may be scarce and deer may be stressed during the 

winter months. For the Downieville Deer Herd, only about 60 acres of critical summer and no mapped 

fawning areas fall within the boundaries of the Tahoe NF. Within critical winter range, Alternative 1 has 

17 motorized route miles, and the all the action alternatives have 14 miles of motorized routes each. 

Within winter range, Alternative 1 has the highest number of motorized route miles (310 miles), where 

direct and indirect disturbance associated with motorized routes could occur when deer are stressed 

during the winter. All the action alternatives are similar in their motorized route miles within winter range 

(242 to 243 miles).

Nevada City Deer Herd: Alternative 1 poses the greatest risk to the Nevada City Deer Herd on all 

key deer habitat types - critical summer, fawning, critical winter, and winter habitats when deer are most 

vulnerable to disturbance. When comparing the miles of motorized routes within critical summer and 

fawning habitat of the Nevada City Deer Herd, Alternative 1 exceeds the action alternatives by at least 30 

miles. For critical winter habitat and winter ranges, Alternative 1 exceeds Alternative 5 by about 84 miles; 

and the remaining action alternatives by an additional 20 miles. 

Loyalton-Truckee Deer Herd: Alternative 1 poses the greatest risk than the action alternatives 

within key ranges, where the Loyalton-Truckee Deer Herd are most vulnerable to factors associated with 
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Tahoe National Forest – 221

motorized vehicles. Motorized route miles for the Loyalton-Truckee Deer Herd are greatest under 

Alternative 1, where motorized route miles exceed all the action alternatives by at least 18 miles 

(Alternative 5) within critical summer ranges (Table 3.03-26). Within fawning habitat, route miles are 

similar for all alternatives, with Alternative 1 exceeding the remaining alternatives by 2-3 miles. 

Alternative 1 poses the greatest concern to the Truckee-Loyalton Deer Herd on both critical summer 

ranges and fawning habitat that are important to for reproduction and rearing young during the summer

months.

Motorized route miles in critical winter and winter ranges are highest in Alternative 1, exceeding the 

action alternatives by 6-7 miles. There are relatively no differences in motorized route miles for the action 

alternatives within winter or critical winter ranges.

Table 3.03-26. Cumulative Motorized Route Miles

Miles of Motorized Routes Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Blue Canyon Deer Herd Critical Summer 212 162.4 161.1 161.6 166.3 162.6 162.0

Fawning 0.1 0 0 0 0.1 0 0

Critical Winter t 61.8 39.2 39.2 39.2 43.1 39.2 39.2

Winter 414.7 306.6 302 306.1 309.6 306.8 306.5

Downieville River Deer 

Herd 

Critical Summer 0.1 0 0 0 0 0 0

Fawning 0.0 0.0 0.0 0.0 0.0 0.0 0.0

Critical Winter 23.0 21.3 21.3 21.3 21.3 21.3 21.3

Winter 310.3 236.5 235.8 236 236.5 236.5 235.8

Nevada City Deer Herd Critical Summer 222.3 193.7 192 192.5 193.7 194.3 192.8

Fawning Habitat 48.3 39.1 38.8 38.8 39.1 39.1 39

Critical Winter 97.2 57.0 57.0 57.1 59.0 57.0 57.0

Winter Habitat 166.3 103.4 103.4 103.5 109 103.5 103.4

Loyalton-Truckee Deer 

Herd 

Critical Summer 117.8 79.4 78.8 78.8 79.4 80.5 78.8

Fawning Habitat 31.8 28.4 28.4 28.4 28.4 28.4 28.4

Critical Winter 

Habitat

22.2 16.2 16.2 16.2 16.2 16.2 16.2

Winter 19.3 15.7 15.7 15.7 15.7 15.7 15.7

Total Cumulative motorized miles for all herds 1747.2 1298.9 1289.7 1295.2 1317.4 1301.1 1296.1

* Alternative 1 includes miles of unauthorized routes associated with continued cross country travel.

Zone of Influence: Tables 3.03-27 through 3.03-30 display the percent of key deer ranges within a 

200-meter Zone of Influence of all motorized routes on both public and private lands within the boundary 

of the Tahoe National Forest for each of the major deer herds: Blue Canyon, Downieville, Nevada City, 

and Loyalton-Truckee. The cumulative effects of all motorized and non-motorized routes are discussed 

for each deer herd for the alternatives.

Blue Canyon Deer Herd: The Blue Canyon Deer Herd has approximately equal amounts of key 

winter range and key summer range (Table 3.03-15). Overall cumulative effects (Table 3.03-27) within 

the Blue Canyon Deer Herd (including unauthorized motorized routes (unauthorized routes), existing 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

222 – Tahoe National Forest

system routes, and non-motorized routes on both NFS and non-NFS lands), indicates that critical winter 

and winter ranges are moderately influenced by existing motorized routes, where habitat effectiveness is 

reduced by 53% and 64%, respectively. Approximately 20% of the key winter ranges are influenced by

cross country travel, including use on existing unauthorized routes. This amount of influence from 

motorized routes could have significant ramifications to the Blue Canyon Deer Herd when the deer are 

already stressed during the winter months, especially since unmanaged cross country travel would 

continue at an unknown rate in the future.

Under all the action alternatives, only a “low” proportion of key deer winter range is influenced by 

proposed motorized route additions (0% to 3%). Under the action alternatives, between 17% and 20% of 

key deer winter range would benefit from the prohibition of cross country travel, including motorized use 

on existing unauthorized routes. However, since these motorized routes would continue to remain in place 

until they are physically revegetated, non-motorized use on these routes may occur which could still 

reduce habitat quality, but the effects would likely be less depending on the type of activity.

Overall cumulative effects to key summer ranges result in an overall “moderate” influence from all 

motorized and non-motorized routes under all the alternatives. Alternative 1 has the highest overall 

cumulative impacts (critical summer - 44%, fawning - 12%). The remaining action alternatives are similar 

to the overall cumulative impact to critical summer and fawning habitats, with Alternative 5, followed by 

Alternative 6 having slightly greater (1-2%) disturbance potential than all the remaining alternatives.

Alternative 1 directly and indirectly affects 9-11% of critical summer ranges and 0-2% fawning habitat

from cross country motorized travel on existing unauthorized routes. 

Alternatives 5 and 6 minimally increase the cumulative impact to critical summer range from the 

addition of motorized routes (1% in critical summer). Only Alternative 5 increases cumulative impacts 

from the reopening of ML 1 roads (1% critical summer, 2% fawning). However, the cumulative effects to 

key summer ranges from both motorized route additions and reopening ML 1 roads would not likely be 

measurable at the forest-wide scale, but may have localized direct and indirect impacts.

The remaining action alternatives do not contribute cumulative impacts to summer ranges. Between 

9% and 11% of key summer range influenced by unauthorized routes would benefit deer due to the 

prohibition of cross country travel, including use on existing unauthorized routes.

Table 3.03-27. Proportion of Blue Canyon Herd Key Deer Ranges within a 200-meter “Zone of Influence”

Blue Canyon Herd Range Type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Direct and Indirect effects of proposed alternatives

Motorized routes to be 

added to NFTS 

(negative impact)*

Critical Summer 11% <1% 0% <1% 1% 1% <1%

Fawning 2% 0% 0% 0% 0% 0% 0%

Critical Winter 20% 0% 0% 0% 3% 0% 0%

Winter 21% 1% 0% 1% 1% 1% 1%

Changes to the NFTS -

Reopened ML 1 Roads

Critical Summer 0% 0% 0% 0% 1% 0% 0%

Fawning 0% 0% 0% 0% 2% 0% 0%

Critical Winter 0% 0% 0% 0% 0% 0% 0%

Winter 0% 0% 0% 0% 0% 0% 0%
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Tahoe National Forest – 223

Blue Canyon Herd Range Type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cumulative effects of past, present, and proposed actions

Existing motorized and 

non-motorized routes 

(NFS and non NFS 

lands) (negative impact)

Critical Summer 33% 33% 33% 33% 33% 33% 33%

Fawning 10% 10% 10% 10% 10% 10% 10%

Critical Winter 33% 33% 33% 33% 33% 33% 33%

Winter 43% 43% 43% 43% 43% 43% 43%

Routes 

decommissioned 

and/or ML 1 closed to 

motorized use (positive 

impact)

Critical Summer 1% 11% 11% 11% 10% 11% 11%

Fawning 0% 2% 2% 2% 0% 2% 2%

Critical Winter 2% 22% 22% 22% 19% 22% 22%

Winter 3% 23% 23% 23% 22% 23% 23%

Total Cumulative Effects

Cumulative Impact 

(both positive and 

negative)

Critical Summer 44% 33% 33% 33% 35% 34% 33%

Fawning 12% 10% 10% 10% 12% 10% 10%

Critical Winter 53% 33% 33% 33% 36% 33% 33%

Winter 64% 44% 43% 44% 45% 44% 44%

* Motorized routes to be added to NFTS: Alternative 1 includes miles of unauthorized routes associated with continued cross 

country travel.

Downieville Deer Herd: Habitat within the boundary of the Downieville Deer Herd has a higher 

proportion of key winter range than key summer range (Table 3.03-15). Therefore, the majority of this 

discussion will focus on cumulative effects to key winter ranges. Only 60 acres of key summer ranges fall

within the boundary of the Downieville Deer Herd. However, Alternative 1 results in a “moderate” 

cumulative impact where 42% of critical summer range is specifically influenced by cross country

motorized travel, including use on existing unauthorized routes. The action alternatives do not affect

critical summer range.

Overall cumulative effects (Table 3.03-28) from all routes within the Downieville Deer Herd 

(including proposed motorized route additions, reopening ML 1 roads, existing system routes, and nonmotorized routes on both NFS and non-NFS lands), indicates all the alternatives “moderately” reduce 

habitat effectiveness within key deer winter ranges (critical winter and winter). 

Alternative 1 poses the greatest risk cumulative impact of reduced habitat effectiveness within key 

winter ranges, where 36% (critical winter) and 47% (winter) would be influenced by existing routes and 

continued cross country motorized travel, including use on existing unauthorized routes. This moderate

influence of routes may potentially result in adverse impacts to the Downieville Herd when deer may be 

stressed during the winter months, especially since unmanaged cross country travel would continue at an 

unknown rate in the future under this alternative.

Under the action alternatives, approximately 29% (critical winter) to 31% (winter) of key winter 

ranges are cumulatively impacted by existing motorized and non-motorized routes, resulting in a 

moderate amount of reduced habitat effectiveness (i.e., increased disturbance) to the Downieville Deer 

Herd. None of the action alternatives would result in adding direct and indirect impacts to existing 

cumulative impacts on key deer winter range from either motorized additions or reopening of ML 1 roads.
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224 – Tahoe National Forest

Under the action alternatives, all existing unauthorized routes within key winter habitat would be 

prohibited from the ban of cross country travel, ranging from 7% (critical winter) to 16% (winter). 

However, these unauthorized routes would continue to remain in place until they are re-vegetated. Nonmotorized use on these unauthorized routes may occur which could still reduce habitat quality, but the 

effects would likely be less than motorized use depending on the type and intensity of non motorized use.

Table 3.03-28. Proportion of Downieville Herd Key Deer Ranges within a 200-meter “Zone of Influence”

Range Type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Direct and Indirect effects of proposed alternatives

Motorized routes to be 

added to NFTS (negative 

impact)*

Critical Summer 42% 0% 0% 0% 0% 0% 0%

Fawning 0% 0% 0% 0% 0% 0% 0%

Critical Winter 7% 0% 0% 0% 0% 0% 0%

Winter 16% 0% 0% 0% 0% 0% 0%

Changes to the NFTS -

Reopened ML 1 Roads

Critical Summer 0% 0% 0% 0% 0% 0% 0%

Fawning 0% 0% 0% 0% 0% 0% 0%

Critical Winter 0% 0% 0% 0% 0% 0% 0%

Winter 0% 0% 0% 0% 0% 0% 0%

Past, present, and proposed actions

Existing motorized and 

non-motorized routes 

(NFS and non NFS lands) 

(negative impact)

Critical Summer 0% 0% 0% 0% 0% 0% 0%

Fawing 0% 0% 0% 0% 0% 0% 0%

Critical Winter 29% 29% 29% 29% 29% 29% 29%

Winter 31% 31% 31% 31% 31% 31% 31%

Routes decommissioned 

and/or ML 1 closed to 

motorized use (positive 

impact)

Critical Summer 0% 42% 42% 42% 42% 42% 42%

Fawning 0% 0% 0% 0% 0% 0% 0%

Critical Winter 0% 7% 7% 7% 7% 7% 7%

Winter 2% 17% 17% 17% 17% 17% 17%

Total Cumulative Impacts

Cumulative Impact (both 

positive and negative)

Critical Summer 42% 0% 0% 0% 0% 0% 0%

Fawning 0% 0% 0% 0% 0% 0% 0%

Critical Winter 36% 29% 29% 29% 29% 29% 29%

Winter 47% 31% 31% 31% 31% 31% 31%

*Motorized routes to be added to NFTS: Alternative 1 includes ZOI of motorized routes unauthorized for motorized use associated 

with continued cross country travel.

Nevada City Deer Herd: The Nevada City Deer Herd has a slightly higher proportion of key summer 

range (~40%) to key winter ranges (~60%) (Table 3.03-15). Overall cumulative effects (Table 3.03-29) 

within the Nevada City Deer Herd (including unauthorized routes, reopening ML 1 roads, existing system 

routes, and non-motorized routes on both NFS and non-NFS lands), indicate Alternative 1 “highly” 

reduces habitat effectiveness within key deer winter habitats where 62% to 67% are cumulatively 

affected, followed by Alternative 5 (40-48%), and then by the remaining action alternatives (40-49%). 

Existing NFTS system and non-NFS routes influences from 40 to 45 percent key winter habitats. 

Alternative 1 poses the greatest risk to reduced habitat effectiveness within key winter ranges where 17 to 
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Tahoe National Forest – 225

27 percent of key winter range affected is attributed to continued cross country motorized use, including 

use of existing unauthorized routes, where current existing NFS and non-NFS motorized routes are 

already influencing key deer winter ranges by at least 40%. This additional reduction in habitat 

effectiveness could pose a significant cumulative impact to the Nevada City Deer Herd, especially 

considering habitat fragmentation within the existing checkerboard ownership pattern in this region, 

including the urban development and encroachment. Increased stress from this amount of motorized use 

could affect this herd’s population numbers, especially since unmanaged cross country travel would 

continue at an unknown rate in the future.

Under Alternative 5, about 2% of key winter ranges within a 200-meter Zone of Influence of 

proposed route additions to the NFTS would add to existing cumulative impacts. Another 1% of key 

winter ranges within a 200-meter Zone of Influence would be impacted by the reopening of ML 1 roads 

with the implementation of Alternative 5.

The remaining action alternatives would not add to existing cumulative impacts to key winter range 

as no motorized routes would be added to the NFTS, and no ML 1 roads would be reopened, which would 

directly or indirectly affect winter range for the Nevada City Deer Herd. Within key winter range, the 

majority (15-27%) of unauthorized routes would be prohibited from motorized use under the action 

alternatives where deer would benefit. However, since these unauthorized routes would continue to 

remain on the ground, and may receive non-motorized use, habitat effectiveness would continue to be

reduced, but the effects would likely be less than motorized use, depending on the intensity, duration, and 

type of activity.

Alternative 1 has the highest overall cumulative impacts (47-63%) to key summer ranges. Alternative 

1 directly and indirectly affects between 9 to 15 percent of critical summer and fawning habitat, 

respectively, from unauthorized routes where cross country travel would continue.

All the action alternatives result in a overall “moderate” cumulative impact to key summer ranges, 

from all motorized and non-motorized routes. The action alternatives would cumulatively affect between 

38% and 49% of key summer ranges (critical summer and fawning) by all motorized and non-motorized 

routes. The remaining action alternatives contributes a relatively small proportion to existing cumulative

impacts, where between 0% and 2% of key summer range is affected by the addition of motorized routes.

None of the ML 1 roads would be reopened for the action alternatives. Under the action alternatives, 

approximately 9-15% of key summer range would be a benefit to the Nevada City Deer Herd, where cross 

country travel influenced by unauthorized routes would be banned. Finally, the prohibition of cross 

country travel on 25,418 acres of key summer range (critical summer and fawning) would be an 

additional benefit to the Nevada City Deer Herd.
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226 – Tahoe National Forest

Table 3.03-29. Proportion of Nevada City Herd Deer Ranges within a 200-meter “Zone of Influence”

Range Type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Direct and Indirect effects of proposed alternatives

Motorized routes to be 

added to NFTS 

(negative impact)*

Critical Summer 9% 1% 0% <1% 1% 2% <1%

Fawning 15% 1% 0% 0% 1% 1% 1%

Critical Winter 27% 0% 0% 0% 0% 0% 0%

Winter 17% 0% 0% 0% 2% 0% 0%

Changes to the NFTS -

Reopened ML 1 Roads

Critical Summer 0% 0% 0% 0% 0% 0% 0%

Fawning 0% 0% 0% 0% 0% 0% 0%

Critical Winter 0% 0% 0% 0% 1% 0% 0%

Winter 0% 0% 0% 0% 1% 0% 0%

Cumulative effects of past, present, and proposed actions

Existing motorized 

and non-motorized 

routes (NFS and non 

NFS lands) (negative 

impact)

Critical Summer 38% 38% 38% 38% 38% 38% 38%

Fawning 48% 48% 48% 48% 48% 48% 48%

Critical Winter 40% 40% 40% 40% 40% 40% 40%

Winter 45% 45% 45% 45% 45% 45% 45%

Routes 

decommissioned 

and/or ML 1 closed to 

motorized use (positive 

impact)

Critical Summer 3% 10% 11% 11% 10% 10% 11%

Fawning 2% 15% 16% 16% 15% 15% 16%

Critical Winter 2% 3% 3% 3% 3% 3% 3%

Winter 2% 19% 19% 19% 18% 19% 19%

Total Cumulative Effects

Cumulative Impact 

(both positive and 

negative)

Critical Summer 47 39% 38% 38% 39% 40% 38%

Fawning 63 49% 48% 48% 49% 49% 49%

Critical Winter 67 40% 40% 40% 40% 40% 40%

Winter 62 45% 45% 45% 48% 45% 45%

* Motorized routes to be added to NFTS: Alternative 1 includes miles of unauthorized routes associated with continued cross 

country travel.

Loyalton-Truckee Deer Herd: Key Summer Ranges: The Loyalton-Truckee Deer Herd has more 

than twice the amount of key summer range (~70%) compared to key winter ranges (~30%) (Table 3.03-

15). Overall cumulative effects (Table 3.03-30) within the Loyalton-Truckee Deer Herd (including 

motorized route additions, reopening ML 1 roads, existing system routes, and non-motorized routes on 

both NFS and non-NFS lands), indicate Alternative 1 has a high risk of negatively influencing habitat 

effectiveness on key summer ranges, where 52% critical summer and 73% fawning habitats are 

cumulatively affected. Under Alternative 1, cross country motorized travel, including use of unauthorized

routes, would reduce habitat effectiveness by an additional 13% and 19% of fawning and critical summer 

ranges, respectively, where current existing NFS and non-NFS motorized routes are already moderately to 

highly influencing key summer ranges. Implementing Alternative 1 could pose considerable cumulative 

impacts to the Loyalton-Truckee Deer Herd from increased stress and disturbance which may potentially

result in altered behavior and/or negatively affect reproductive productivity. Ultimately, total cumulative 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 227

effects of Alternative 1 could result in downward population trends, especially since unmanaged cross 

country travel would continue at an unknown rate in the future.

All the action alternatives reduce habitat effectiveness at a moderate to high proportion within key 

deer summer habitats where between 33% of fawning and 60% critical summer ranges are cumulatively 

affected, predominately from existing routes. Alternatives 5 and 6, each negatively influences a small 

amount of critical summer range (less than 1-2%), where overall habitat effectiveness within critical 

summer and fawning habitat would not measurably add to existing cumulative effects. The remaining 

action alternatives do not affect key summer ranges from the addition of motorized routes or the 

reopening of ML 1 roads.

Alternative 6 adds a small amount of cumulative effects from motorized route additions (2%) and 

reopening of ML 1 roads (less than 1%) within key summer habitat for the Loyalton-Truckee Deer Herd. 

The remaining action alternatives would not add to existing cumulative impacts to key summer range 

since no motorized routes would be added to the NFTS. Alternative 5 affects less than 1 percent of critical 

summer range from reopening ML 1 roads.

Key Winter Ranges: The vast majority of existing unauthorized routes within key winter habitat 

would not be added to the NFTS under the action alternatives, where deer would benefit. However, since 

these motorized routes would continue to remain in place until they are restored, non-motorized use on 

these routes may occur which could reduce deer habitat quality, but the effects would likely be less 

depending on the type of activity and the intensity of use.

Alternative 1 directly and indirectly affects an average of 11% of key winter ranges from cross 

country motorized travel, including use on existing unauthorized routes. Total cumulative effects from all 

existing routes and continued cross country travel on unauthorized routes influences a moderate 

proportion (33-48%) of key winter ranges where habitat effectiveness within key winter ranges could be 

reduced under the No Action Alternative. 

Under all the action alternatives, cumulative effects to key winter ranges results in an overall 

“moderate” influence where between 22% (critical summer) and 37% (fawning) key summer ranges 

would be affected. Under all the action alternatives, approximately 11% of key winter ranges would 

benefit from the ban of cross country travel where disturbance from motorized use would be eliminated, 

including on 2,173 acres.
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228 – Tahoe National Forest

Table 3.03-30. Proportion of Loyalton-Truckee Herd Key Deer Ranges within a 200-meter “Zone of Influence” 

Range Type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Direct and Indirect effects of proposed alternatives

Motorized routes to be 

added to NFTS (negative 

impact)*

Critical Summer 19% 0% 0% 0% 0% 2% 0%

Fawning 13% 0% 0% 0% 0% 0% 0%

Critical Winter 11% 0% 0% 0% 0% 0% 0%

Winter 11% 0% 0% 0% 0% 1% 0%

Changes to the NFTS -

Reopened ML 1 Roads

Critical Summer 0% 0% 0% 0% <1% <1% 0%

Fawning 0% 0% 0% 0% 0% 0% 0%

Critical Winter 0% 0% 0% 0% 0% 0% 0%

Winter 0% 0% 0% 0% 0% 0% 0%

Cumulative effects of past, present, and proposed actions

Existing motorized and 

non-motorized routes 

(NFS and non NFS lands) 

(negative impact)

Critical Summer 33% 33% 33% 33% 33% 33% 33%

Fawing 60% 60% 60% 60% 60% 60% 60%

Critical Winter 22% 22% 22% 22% 22% 22% 22%

Winter 37% 37% 37% 37% 37% 37% 37%

Routes decommissioned 

and/or ML 1 closed to 

motorized use (positive 

impact)

Critical Summer 2% 21% 22% 22% 21% 20% 22%

Fawning 3% 15% 15% 15% 15% 15% 15%

Critical Winter 3% 13% 13% 13% 13% 13% 13%

Winter 0% 11% 11% 11% 11% 10% 11%

Total Cumulative Effects

Cumulative Impact (both 

positive and negative)

Critical Summer 52% 33% 33% 33% 33% 33% 33%

Fawning 73% 60% 60% 60% 60% 60% 60%

Critical Winter 33% 22% 22% 22% 22% 22% 22%

Winter 48% 37% 37% 37% 37% 37% 37%

* Motorized routes to be added to NFTS: Alternative 1 includes miles of unauthorized routes associated with continued cross 

country travel.

Overall Cumulative Effects from Past, Present, and Reasonably Foreseeable Future Actions: 

Past and current cumulative effects to mule deer include current and historic grazing of mule deer habitat; 

loss of habitat through catastrophic wildfires; timber and fuels management where cover and forage has 

been reduced or removed; urban development and expansion within a highly checkerboard land 

ownership pattern; and recreational activities including hunting, camping, and general recreation activities 

including all forms of motorized use including 4 wheeled drive vehicles, ATVs, and motorcycles.

The Tahoe NF currently has 31 active livestock grazing allotments including both cattle and sheep. 

Tahoe LRMP standards and guidelines, as amended by the Sierra Nevada Forest Plan Amendment (USFS 

2004), for grazing are generally reducing the amount of grazing impacts on rangelands. 

Appendix H (Reasonably Foreseeable Projects and Cumulative Effects) provides a list and 

description of past, present, and reasonably foreseeable projects on NFS and private lands within the 

Tahoe NF boundary. Some, but not all, of these activities will contribute to impacts to the mule deer 

within the Tahoe NF boundary. Since 1990, more than 130,000 acres of vegetation management activities 
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Tahoe National Forest – 229

have occurred on the Tahoe NF. Some, but not all, have resulted in impacts to mule deer habitats. 

Between 2001 and 2008, nearly 17,000 acres of forest vegetation and fuels projects were completed, 

which primarily thinned, masticated, and/or burned vegetation to reduce the potential for catastrophic 

wildfires. These treatments generally do not increase forage condition for deer because they do not 

usually result in reducing the canopy cover below 40%, except for group selection harvest treatments on 

the Sierraville RD. Group selection harvests are expected to increase forage condition and increase forest 

structural diversity. These thinning treatments may result in the short-term reduction in cover for deer, 

though it is expected that in the longer term, habitat will be protected by reducing wildfire risk. Many 

recent, current, and future vegetation and fuels reduction projects are emphasizing habitat improvement 

for deer by removing competing conifers within oak habitats and aspen habitats which are designed to 

enhance mule deer foraging condition. Between 1994 and 2008, approximately 95,000 acres burned on 

the Tahoe NF, some of which have removed mule deer habitat. 

Currently, there is a high demand for recreational use on the Tahoe NF due to its close proximity to 

urban centers. The Tahoe NF provides a wide variety of recreational experiences including developed and 

dispersed camping, hiking, fishing, hunting, wildlife viewing, winter sports activities (downhill skiing, 

cross country skiing, snowmobiling), summer OHV use, and a variety of other non-motorized use 

(equestrian use and mountain biking). Recreational use on the Tahoe NF has significantly increased 

compared to the past 20 to 30 years. Because of the proximity to urban areas and population growth, 

increased recreational use on the Tahoe NF is expected to continue to increase in the future including 

camping, hiking, fishing, wildlife viewing, hunting, and OHV use. Generally, the increase in recreational 

use on the Tahoe NF has the potential to cause an increase in negative interactions between humans and 

mule deer. Future increase in recreational use on the Tahoe NF is expected, and therefore, increased 

disturbance to mule deer would be expected, particularly during the summer months. Two non-motorized 

routes are being proposed for development in the near future. The development and use of these routes

may slightly increase disturbance to mule deer since deer have been shown to demonstrate increased 

responses to humans when humans are in close proximity to deer, especially when humans are on foot.

Table 3.03-31 summarizes the major reasonably foreseeable future actions, including fuels, 

vegetation, recreation, range allotment plans, non-motorized trail development, and special use permit 

reissuance’s and a description of the potential impact to mule deer and their habitat.
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230 – Tahoe National Forest

Table 3.03-31. Direct, Indirect, and Cumulative Impact to Mule Deer from Reasonably Foreseeable Future 

Projects

Project type Number of 

Projects

Mule Deer Direct and Indirect 

Impact

Overall Cumulative Impact

Vegetation management/

fuels reduction projects –

thinning, group select, 

~30 Short-term disturbance from 

harvest activities, changes in 

cover, foraging habitat 

enhancement in oak habitats.

• Short-term adverse impacts 

during harvest.

• Long-term beneficial cumulative 

effects by reduced risk of habitat 

loss from high severity wildfires.

Aspen enhancement 8 Cover and forage habitat 

enhancement 

• Short-term adverse impacts 

during implemtation

• Long-term beneficial cumulative 

effects through improved forage 

and cover production

Mastication, site prep 

and release of small 

trees, and prescribed 

burns

~20 Short-term disturbance during 

project implementation

Various site-specific effects.

• Short-term adverse impacts 

during implementation

• Long-term beneficial cumulative 

beneficial effects depending on 

site-specific conditions

Hazard tree removal 4 Minimal impact. Short-term 

disturbance during harvest.

None to minimal cumulative impact

Salvage Fire Burned 

Trees

2 Minimal impact. Short-term 

disturbance during harvest.

None to minimal cumulative impact

Fish passage 

construction project

1 Short-term disturbance during 

project implementation.

No cumulative impact

Non-motorized Trail 

development

2 Short-term disturbance during trail 

construction, some increased 

public use may increase 

disturbance.

Slight increase in cumulative 

impact.

Designate Energy 

Corridor

1 N/A programmatic administrative 

action

Unknown, site-specific cumulative 

impacts may occur depending on 

location of the corridor.

When considering all the cumulative effects of past, present, and reasonably foreseeable future 

impacts from grazing, vegetation/fuels projects, wildfires, and recreation, Alternative 1 poses the greatest 

risk to the 4 major deer herds on the Tahoe NF, where between 12% and 27% of key winter ranges are 

influenced by unauthorized routes, and between 7% and 41% of key summer ranges are affected, 

depending on the deer herd. Alternative 5 slightly increases the amount of cumulative effects on key deer 

habitats over the other action alternatives, where site specific localized effects may occur. The remaining 

action alternatives are similar and only slightly increase overall cumulative impacts to the 4 major deer 

herds on the Tahoe NF. Alternative 3 does not add any motorized routes to the NFTS, so does not add to 

existing cumulative impacts. All the action alternatives will result in a beneficial impact to all deer ranges 

across the Tahoe NF from the ban on cross country travel, including motorized travel on approximately 

1,123 to 1,294 miles of existing unauthorized routes depending on the alternative. It is expected that nonmotorized use may occur on these unauthorized routes which would likely result in less disturbance to 

mule deer. However, some studies indicate that certain non-motorized activities (hiking, mountain 

bicycling, equestrian, etc.) could actually result in greater disturbance to mule deer. At any rate, the 
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Tahoe National Forest – 231

amount of disturbance caused by non-motorized use will depend on the type, intensity and duration of the 

use. As existing unauthorized routes become re-vegetated and recover over time, either through active or 

passive restoration efforts, overall mule deer disturbance from motorized routes is expected to diminish. 

In addition, Alternatives 4, 5, and 6 would benefit deer on winter ranges through the implementation 

of wet weather closures on native surfaced roads and trails.

Mule Deer: Management Direction

Management Indicator Species (MIS) Summary: The Sierra Nevada Forests Bioregional MIS Report

and Travel Management MIS Project-Level Report are incorporated by reference. Alternative 1 poses the 

greatest cumulative effects to mule deer MIS oak-associated hardwood and hardwood/conifer habitat on 

the Tahoe NF where 13,695 acres out of 99,238 acres of mule deer habitat would be affected within a 

200-meter Zone of Influence of existing unauthorized routes. This would add to existing cumulative 

effects by approximately 14%. Alternative 1 could contribute to a downward trend in mule deer habitat 

effectiveness within oak-associated and hardwood/conifer habitats on the Tahoe NF. 

All the action alternatives would benefit mule deer oak habitats by prohibiting cross-country. All the 

action alternatives would influence from 0% to 0.6% oak-associated hardwood and hardwood/conifer 

habitat at the Tahoe NF scale (Alt 3 adds no impacts, Alt 5 adds the most) from addition of motorized 

routes. In addition Alternative 5 proposes to reopen ML 1 roads which would affect an additional 1% of 

motorized influence on mule deer oak habitat. None of the action alternatives would alter existing trends

in oak-associated hardwood and hardwood/conifer habitat on the Tahoe NF from either motorized route 

additions or reopening ML 1 roads.

The change in the class of vehicles would have no effect to mule deer habitat, since the change in 

class of vehicles on existing motorized routes would generally not affect mule deer habitat condition. Wet 

weather seasonal restrictions under Alternatives 4, 5, and 6 on all native surfaced roads and motorized 

trails would benefit mule deer habitat effectiveness through the reduced disturbance and avoidance when 

motorized use on native surfaced routes that are seasonally restricted. Finally, cross country travel would 

be prohibited on 65,329 acres with the implementation of the action alternatives where disturbance, 

avoidance, and abandonment by mule deer would be reduced or eliminated. Alternative 1 would have the 

greatest risk to mule deer habitats, where cross country travel would continue, affecting 65,329 acres of 

oak-associated hardwood and hardwood/conifer habitat. Refer to Table 3.03-32.
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232 – Tahoe National Forest

Table 3.03-32 Acres of Cross Country Travel Prohibitions and Proportion of Mule Deer MIS habitat within a 

200-meter “Zone of Influence” of Proposed Route Additions to the NFTS

Alt 11 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Acres of Cross Country Travel Prohibitions Within Oak-Associated Hardwood and

Hardwood/Conifer Habitats

Acres oak-associated and hardwood conifer 

habitat where cross country travel would be 

prohibited

0 65,329 65,329 65,329 65,329 65,329 65,329

Proportion of Mule Deer MIS habitat within a 200-meter “Zone of Influence” of Proposed Route Additions

Acres Oak-associated hardwood and 

hardwood/conifer habitats

13,695 496 0 99 595 298 199

Proportion of Sierra Nevada 

Habitat

809,000 1.7% 0.06% 0% <0.01% 0.01% 0.04% 0.02%

Habitat Security Risk in Sierra Nevada Low Low Low Low Low Low Low

Proportion of Tahoe NF Habitat2 99,238 14% 0.5% 0% 0.1% 0.6% 0.3% 0.2%

Habitat Security Risk in Tahoe NF Low Low Low Low Low Low Low

Proportion of Mule Deer MIS habitat within a 200-meter “Zone of Influence” of Reopned ML 1 Roads

Acres Oak-associated hardwood and 

hardwood/conifer habitats

0 0 0 208.0 812.4 0 0

Proportion of Sierra Nevada 

Habitat 

809,000 0% 0% 0% <0.01% 0.1% 0% 0%

Habitat Security Risk in Sierra Nevada Low Low Low Low Low Low Low

Proportion of Tahoe NF Habitat 99,238 0% 0% 0% 0.2% 0.8% 0% 0%

Habitat Security Risk in Tahoe NF Low Low Low Low Low Low Low

Total acres oak-associated hardwood and 

hardwood/conifer Habitat Affected

13,695 496 0 307 1,407 298 199

Total proportion of Sierra Nevada

Habitat Affected

1.7% 0.06% 0% 0.04% 0.11% 0.04% 0.02%

Total proportion of Tahoe NF

Habitat Affected

14% 0.1% 0% 0.3% 1.4% 0.3% 0.2%

1

Alternative 1 includes existing routes unauthorized to motorized public use that would continue with the continuance of cross

country travel.

2

The Zone of Influence within 200 meters of motorized routes includes both NFS and non-NFS lands within the boundary of the 

Tahoe NF due to the complex checkerboard pattern. The proportion of habitat affected likely over-represents the actual amount of 

habitat affected on NFS lands

Summary of Mule Deer Status and Trend at the Bioregional Scale. The Tahoe NF LRMP (as 

amended by the SNF MIS Amendment) requires bioregional-scale habitat and distribution population 

monitoring for the mule deer; hence, the effects analysis for the Tahoe NF Motorized Travel Management 

Project must be informed by both habitat and distribution population monitoring data. The sections below 

summarize the habitat and distribution population status and trend data for the mule deer. This 

information is drawn from the detailed information on habitat and population trends in the Sierra Nevada 

Forests Bioregional MIS Report (USDA Forest Service 2008), which is hereby incorporated by reference.

Habitat Status and Trend. There are currently 809,000 acres of oak-associated hardwood and 

hardwood/mixed conifer habitat on NFS lands in the Sierra Nevada. The trend is slightly increasing 

(within the last decade, changing from 5% to 7% of the acres on NFS lands).
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 233

Population Status and Trend. The mule deer has been monitored in the Sierra Nevada at various 

sample locations by herd monitoring (spring and fall) and hunter survey and associated modeling (CDFG 

2007). California Department of Fish and Game (CDFG) conducts surveys of deer herds in early spring to 

determine the proportion of fawns that have survived the winter, and conducts fall counts to determine 

herd composition (CDFG 2007). This information, along with prior year harvest information, is used to 

estimate overall herd size, sex and age rations, and the predicted number of bucks available to hunt (ibid). 

These data indicate that mule deer continue to be present across the Sierra Nevada, and current data at the 

range wide, California, and Sierra Nevada scales indicate that, although there may be localized declines in 

some herds or Deer Assessment Units, the distribution of mule deer populations in the Sierra Nevada is 

stable.

Relationship of Project-Level Habitat Impacts to Bioregional-Scale Mule Deer Trend. 

Alternative 1 results the greatest amount of oak-associated hardwood and hardwood/conifer habitat 

13,695 acres (1.7% of Sierra Nevada-wide habitat) affected by cross country travel, including use on 

existing unauthorized routes. 

All the action alternatives would result in a benefit to mule deer and oak-associated hardwood and 

hardwood/conifer habitats, since cross country travel would be banned. Alternative 5 benefits the least 

where 1,407 acres or 0.1% of Sierra Nevada-wide habitat within oak-associated hardwood and 

hardwood/conifer habitat types would be reduced in habitat effectiveness from motorized route additions 

and reopened ML 1 roads. The remaining action alternatives would affect from 0 to less than 0.1% Sierra 

Nevada wide habitat. Based on the small percentage of habitat affected, implementing the Tahoe NF 

Motorized Travel Management Project would not alter the existing habitat trend, nor would it lead to a 

change in the distribution of mule deer across the Sierra Nevada bioregion.

Compliance with the Forest Plan and Other Direction: The Tahoe NF LRMP (1990) provides 

management direction for deer habitat management in the following Standard and Guideline: 

Limit vehicle access on key deer winter ranges when deer are present. Also limit vehicle access in 

key summer range habitats during periods of migration and fawning. 

The Tahoe Travel Management Project provides project design standards for minimizing effects of 

deer habitat on key deer winter ranges and key summer ranges, including maintaining existing LRMP 

OHV seasonal restrictions for deer, the prohibition of cross country travel ( acres), and wet weather 

seasonal restrictions. The effects of these actions and the addition of motorized routes to the NFTS and 

established “Open Areas” were analyzed within key deer habitats for the major deer herds on the Tahoe 

NF, including Blue Canyon herd, Downieville herd, Nevada City herd, and the Loyalton-Truckee herd. 

The analysis of effects indicated that Alternative 1 least complies with the Tahoe NF LRMP Standard and 

Guideline and poses the greatest risk to the four major deer herds, where between 12% and 27% of key 

winter ranges are influenced by unauthorized routes, and between 7% and 41% of key summer ranges are 

affected, depending on the deer herd. All of the action alternatives meet this Standard and Guideline by 

limiting access to varying degrees. Of the action alternatives, Alternative 5 least limits vehicle access,

while Alternative 3 most limits access. Alternatives 2, 4, 6, and 7 comply with LRMP deer direction 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

234 – Tahoe National Forest

similarly, somewhat less than Alternative 3, and slightly more than Alternative 5. All the action 

alternatives would result in a beneficial impact to all deer ranges across the Tahoe NF from the ban on 

cross country travel, including motorized travel on approximately 1,123 to 1,294 miles of existing 

unauthorized routes depending on the alternative. In addition, Alternatives 4, 5, and 6 would benefit deer 

on winter ranges through the implementation of wet weather closures on native surfaced roads and 

motorized trails.

LRMP Amendment to Change Season of Use in the Humbug-Sailor Management Area: Due to 

the complexity of factors that affect deer population trends (i.e., urbanization, hunting, long-term habitat 

condition, annual weather variation, etc.), it is not likely that amending the LRMP to change the season of 

motorized use within the Humbug-Sailor Management Area under Alternatives 5 and 6 by 2-3 months 

and for Alternative 2 by 6 months, affecting less than 8% of key winter range, would significantly affect 

deer such that population numbers of the Blue Canyon deer herd would change. In addition, the overall 

effects of the prohibition of cross country travel on 16,108 acres of key winter range, including on 

unauthorized routes and imposing additional motorized wet weather seasonal restrictions within key 

winter range and surrounding areas would provide an overall net benefit by reducing motorized 

disturbance within the Blue Canyon Deer Herd under all the action alternatives, and therefore, would 

meet the intent of Forest Plan S&G to “Limit vehicle access on key deer winter ranges when deer are 

present.”

Guidance regarding management indicator species (MIS) set forth in the Tahoe NF LRMP as 

amended by the 2007 SNF MIS Amendment ROD directs Forest Service resource managers to (1) 

at project scale, analyze the effects of proposed projects on the habitat of each MIS affected by 

such projects, and (2) at the bioregional scale, monitor populations and/or habitat trends of MIS, 

as identified in the Tahoe NF LRMP as amended.

The mule deer was selected as Management Indicator Species for the Tahoe NF as amended by the 

2007 SNF MIS Amendment ROD. Project-level effects to mule deer were analyzed for each alternative 

and disclosed in the sections above under Environmental Consequences in the MIS Summary Section and 

in the Tahoe NF Motorized Travel Management Project Level MIS report, which is incorporated by 

reference. In addition, population and habitat trends for mule deer are conducted at the bioregional scale. 

Oak Woodland and Oak-Conifer Associated Species:

Affected Environment

Introduction: Species within the Oak Woodland and Mixed Oak-Conifer Forest Group include mule 

deer, wild turkey, band-tailed pigeon, western gray squirrel, and the pallid bat. The mule deer is identified 

as a Management Indicator Species in the Sierra Nevada Forests (Sierra Nevada Forests Management 

Indicator Species Amendment Record of Decision 2007). See previous section for mule deer MIS 

analysis. The pallid bat is designated as a Forest Service Sensitive Species by the Regional Forester.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 235

Species associated with pure oak woodland and mixed oak-conifer forest have the potential to be 

affected by road and trail-associated factors. The relationship between road and motorized trail associated 

factors to population trends of these species is unknown.

Mortality from hunting or trapping: In general, roads facilitate access to the hunted species and 

their habitat in this group. Impacts of road and trail associated factors to wild turkeys varies. Turkeys in 

Alabama were found to show no apparent impact when approached by vehicles. However, after several 

years of being hunted and receiving an increase in disturbance, turkeys went for cover when vehicles 

approached (Wright and Speake 1975 In: Joslin and Youmans, coordinators 1999).

Fragmentation, Edge and Microclimate Effects: Roads can also create edge effects which may

alter microclimates near roads. This may enhance habitat for these species or may have negligible impacts 

to their habitat overall.

Disturbance and changes in behavior: Pallid bats may be sensitive to human disturbance. If roost 

sites are disturbed by route associated factors, local pallid bat populations may be negatively impacted.

Summary of Route associated factors to hardwood associated species:

• Mortality from hunting or trapping as facilitated by road and trail access (wild turkey, western 

gray squirrel, band-tailed pigeon)

• Changes to habitat microclimate associated with the edge induced by roads or trails 

• Changes in behavior that may lead to loss of reproductive success due to trail and road associated 

factors.

Oak Woodland and Oak-Conifer Associated Species: 

Environmental Consequences

Indicators to Measure Direct and Indirect Effects

Cross Country Travel: The acres of cross country travel that would be prohibited within oak and oakconifer habitats are determined for each of the alternatives.

Additions to the NFTS: For motorized additions to the NFTS, the Zone of Influence within oak and 

oak-conifer habitat is analyzed by alternative under the Management Indicator section for the mule deer.

Establishment of “Open Areas”: Establishment of “Open Areas” is discussed under “Effects 

Common to All Species.”

Changes to the NFTS: The Zone of Influence of reopened Maintenance Level 1 roads is determined 

for each alternative within oak and oak-conifer habitats under the Management Indicator Section of the 

Deer Environmental Consequences Section. The changes in class of vehicle are analyzed under 

“Summary of Effects Common to All Species.”

Amendments to the Forest Plan: The effects to oak woodland and oak-conifer species are analyzed 

by their potential to be affected by the Forest Plan amendments of removing seasonal restrictions to deer 

in the Deer Environmental Consequences Section.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

236 – Tahoe National Forest

Direct and Indirect Effects common to all oak woodland and oak-conifer species

Prohibition of Cross Country Travel: Alternative 1 poses the greatest risk to oak associated species 

where cross country travel would not be prohibited on 65,329 acres, where oak associated species could 

be subjected to disturbance, avoidance, and abandonment. The remaining action alternatives would 

prohibit cross country travel within oak and oak/conifer woodlands on approximately 65,329 acres.

Changes to the NFTS (Change in wet weather seasonal restrictions): Alternatives 4, 5, and 6 

would impose wet weather seasonal restrictions on all native surfaced roads and trails, where oak 

associated species would benefit from the reduction of noise and disturbance associated with motorized 

use, especially motorized routes that are within oak and oak-conifer associated habitats. Alternatives 1, 2, 

3, and 7 do not impose wet weather restrictions on native surfaced motorized routes and therefore, there 

would be no benefit to oak and oak-conifer associated species from wet weather seasonal restrictions 

under these alternatives.

Summary of Direct and Indirect Effects 

Table 3.03-33 summarizes the overall net effect to oak and oak-conifer habitat from the proposed actions 

from motorized route additions to the NFTS, prohibition of cross country travel, wet weather restrictions, 

and seasonal closures.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 237

Table 3.03-33. Oak and Oak/Conifer Habitat - Summary of Overall Net Direct and Indirect Effects*

Indicator Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres of Habitat Where Travel is 

Prohibited

33,909 65,329 65,329 65,329 65,329 65,329 65,329

Motorized Route Additions to NFTS

Trend of Effect Negative (most 

impactive 

alternative)

Minimal Effect No Effect No Effect Slight Negative 

(2nd most 

impactive 

following Alt 1)

Minimal Effect No Effect

200-meter Zone of Influence 14% <1% 0% 0% 1% <1% 0%

Establishment of Motorized “Open 

Areas”

No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Changes 

to the 

NFTS

Change in Season of Use 

(wet weather restrictions)

No Effect No Effect No Effect Beneficial from 

reduced 

disturbance

Beneficial from 

reduced 

disturbance

Beneficial from 

reduced 

disturbance

No Effect

Change in Class of 

Vehicles

No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Reopened 

Maintenance 

Level 1 

Roads

Trend of 

Effect

No Effect No Effect No Effect No Effect Negative (Most 

impactive)

No Effect No Effect

200 meter 

ZOI

0% 0% 0% 0% 1% 0% 0%

Amendments to the Forest Plan No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Overall Net Effect of Proposed 

Actions 

Most impactive 

alternative. 

Negatively effects 

14% oak and oakconifer habitat 

acres primarily 

from continued 

motorized cross 

country travel.

Benefits 65,329 

acres oak and 

oak-conifer 

habitat acres 

where cross 

country travel is 

prohibited; 

motorized route 

additions affects 

<1% habitat; 

overall reduces 

habitat 

fragmentation.

Benefits 65,329 

acres oak and 

oak-conifer habitat 

acres where cross 

country travel is 

prohibited

Benefits 65,329 

acrs oak and oakconifer habitat 

acres where cross 

country travel is 

prohibited; overall 

reduces habitat 

fragmentation.

Benefits 65,329 

acres oak and 

oak-conifer habitat 

acres where cross 

country travel is 

prohibited, 

negatively affects 

approx. 2% habitat 

from combined 

motorized 

additions and 

reopened ML 1 

routes; overall 

reduces habitat 

fragmentation.

Benefits 65,329 

acres oak and oakconifer habitat 

acres where cross 

country travel is 

prohibited; 

motorized route 

additions affects 

<1% habitat; 

overall reduces 

habitat 

fragmentation.

Benefits 65,329 

acrs oak and 

oak-conifer 

habitat acres 

where cross 

country travel is 

prohibited; 

overall reduces 

habitat 

fragmentation.

*Alternative 1 includes existing unauthorized routes that are associated with continued cross country travel.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

238 – Tahoe National Forest

Oak and Oak-conifer Habitat: Cumulative Effects to Habitat in the Analysis Area

Motorized Route Density: Motorized route density provides a relative index of cumulative impacts to 

oak associated species. For example, motorized route density levels can provide a relative index of the 

amount of human access to hunt species, including mule deer, wild turkey, gray squirrel, and the bandtailed pigeon, which can have an impact on population numbers. Roads and motorized trails have the 

potential to cause adverse impacts to pallid bats through the loss of oak habitat, especially for urban 

expansion on private lands. Motorized routes within oak habitats may lead to changes in behavior and 

may ultimately result in reduced reproductive success for oak associated species.

The cumulative effects to oak associated species were determined by assessing the proportion of pure 

oak and oak-conifer habitats for motorized route densities, including all existing system routes, proposed 

route additions, and Maintenance Level 1 routes that would be reopened. Motorized route densities were 

determined between 0 and 6 miles/square mile (Table 3.03-34) across the Tahoe NF. Under Alternative 1, 

with continued cross country motorized travel, including continued use of existing unauthorized routes, 

84% of the Tahoe NF oak habitats (pure oak woodland and mixed oak-conifer types) would have 

motorized route densities that exceed 2 miles/square mile, where increased access to hunters may 

potentially have an impact on oak associated species, such as wild turkey, gray squirrels, and band-tailed 

pigeon. Pallid bats have the greatest potential to be disturbed within oak habitats under Alternative 1 

compared to all the action alternatives. 

Alternative 5 would result in approximately 75% of oak habitat with motorized route densities 

exceeding 2 miles/square mile. The remaining alternatives would have similar proportions of oak habitats 

(71-72%) where motorized route densities would exceed 2 miles/square mile.

Table 3.03-34. Proportion of Oak Habitat (Percent) with Motorized Route Densities between 0 and 6 

miles/square mile 

Motorized Route Density 

(miles/square mile)

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

0-2 miles/square mile 17% 29% 29% 29% 27% 29% 29%

2-4 miles/square mile 48% 64% 64% 64% 67% 65% 64%

4-6 mile/square mile 35% 7% 7% 7% 8% 7% 7%

6+ miles/square mile 1% <1% 0% <1% <1% <1% <1%

*Alternative 1 includes route density of existing unauthorized routes, with continued cross country travel.

Fox Sparrow and Shrubland (West-Slope Chaparral) Habitat:

Affected Environment

The fox sparrow was selected as the MIS for shrubland (chaparral) habitat on the west-slope of the Sierra 

Nevada, comprised of montane chaparral (MCP), mixed chaparral (MCH), and chemise-redshank 

chaparral (CRC) as defined by the California Wildlife Habitat Relationships System (CWHR) (CDFG 

2005). The Sierra Nevada Forests Bioregional MIS Report and Travel Management MIS Project-Level 

Report are incorporated by reference. Recent empirical data from the Sierra Nevada indicate that, in the 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 239

Sierra Nevada, the fox sparrow is dependent on open shrub-dominated habitats for breeding (Burnett and 

Humple 2003, Burnett et al. 2005, Sierra Nevada Research Center 2007). 

The project area, comprised of the Tahoe NF boundary, currently has 62,928 acres of shrubland 

habitat. Shrubland habitat is comprised of various age classes that range from young shrubs, intermediate 

age classes, and mature to decadent shrub classes. In this section, where effects to fox sparrow are noted, 

it is assumed that effects also occur for the shrubland habitat also.

Fox Sparrow: Environmental Consequences

Indicators to Measure Direct and Indirect Effects

Cross Country Travel: The acres of cross country travel that would be prohibited within shrubland 

habitat (west-slope chaparral) habitats are determined for each of the alternatives.

Additions to the NFTS (Zone of Influence): For the proposed alternatives, the Zone of Influence of 

disturbance used in this analysis was the amount of shrubland habitat (west-slope chaparral) that fell 

within a 200 meter Zone of Influence of proposed motorized routes. The No Action Alternative

(Alternative 1) was analyzed by determining the amount of shrubland habitat that fell within a 200 meter 

Zone of Influence of existing unauthorized routes.

Establishment of “Open Areas”: Establishment of “Open Areas” is discussed under “Summary of 

Effects Common to All Species.”

Changes to the NFTS: The Zone of Influence of reopened Maintenance Level 1 roads is determined 

for each alternative within shrubland habitat (west-slope chaparral). The changes in class of vehicle and 

changes in seasonal restrictions are analyzed under “Summary of Effects Common to All Species.”

Fox Sparrow: Direct and Indirect Effects 

Cross Country Travel. Under Alternative 1, cross country travel would continue, potentially affecting 

39,639 acres of shrubland (west slope chaparral) habitat and potentially causing reduced habitat 

effectiveness through disturbance, avoidance, and abandonment for the fox sparrow. All action 

alternatives would prohibit this cross country travel, accordingly reducing or eliminating those existing 

impacts. Existing LRMP motorized prohibitions would remain in effect.

Additions to the NFTS (Zone of Influence): The direct and indirect effects to fox sparrow shrubland 

habitat from proposed motorized route additions results in a decrease in habitat quality from disturbance, 

displacement and/or avoidance of habitat as a result of activities associated with motorized vehicle use. 

Based on the analysis conducted for fox sparrow shrubland habitat, Alternative 1 would affect the greatest 

amount of habitat within a 200-meter Zone of Influence (Table 3.03-35). Approximately 10,068 acres or 

1% of Sierra Nevada-wide habitat would be affected by continued cross country travel on existing 

unauthorized routes. Alternative 5 has the next highest direct and indirect effects to fox sparrow habitat, 

where 1,259 shrubland acres or 0.14% of Sierra Nevada-wide habitat would be affected by proposed 

motorized route additions to the NFTS. Alternatives 2, 6, and 7 are similar in their affects to shrubland 

habitat, where 629 acres or 0.07% of Sierra-wide habitat would be affected. Alternatives 3 and 4 do not 

result in any direct or indirect effects to fox sparrow habitat.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

240 – Tahoe National Forest

Table 3.03-35. Proportion of Fox Sparrow MIS habitat within a 200-meter “Zone of Influence” of Proposed 

Route Additions

Alt 11 Alt 2, 6, 7 Alt 3, 4 Alt 5

Acres Shrubland (west-slope chaparral 

types) within ZOI

Habitat 

Acres

10,068 629 0 1,259

Proportion of Habitat in Sierra Nevada 922,000 1% 0.07% 0% 0.14%

Proportion of Habitat in Tahoe NF 

boundary2 62,928 16% 1% 0% 2%

1 Alternative 1 includes existing unauthorized motorized routes that would continue with cross country travel. 2 The Zone of Influence within 200 meters of motorized routes includes both NFS and non-NFS lands within the boundary of the 

Tahoe NF due to the complex checkerboard pattern. The proportion of habitat affected likely over-represents the actual amount of 

habitat affected on NFS lands.

Changes to the NFTS (Reopened ML 1 Roads): The direct and indirect effects to fox sparrow 

shrubland habitat from reopened ML 1 roads would result in a decrease in habitat quality from 

disturbance, displacement and/or avoidance of habitat as a result of activities associated with motorized 

vehicle use. Based on the analysis conducted for fox sparrow shrubland habitat, Alternative 5 would 

affect the greatest amount of habitat affected by reopened ML 1 roads within a 200-meter Zone of 

Influence (Table 3.03-36). Approximately 629 acres or .07% of Sierra Nevada-wide habitat would be 

affected by reopening ML 1 roads to motorized use. Alternative 6 reopens a very short segment of ML 1 

road within fox sparrow habitat, but the amount is so small that the effects to habitat would be negligible.

Therefore, Alternatives 1, 2, 3, 4, 6, and 7 do not affect shrubland habitat, and would not result in any 

direct or indirect effects to fox sparrow habitat.

Table 3.03-36. Proportion of Fox Sparrow MIS habitat within a 200-meter “Zone of Influence” of Reopened ML 

1 Roads

Alt 1, 2,3, 4 6, 7 Alt 5

Acres Shrubland (west-slope chaparral types) Habitat Acres 0 629

Proportion of Habitat in Sierra Nevada 922,000 0% .07%

Proportion of Habitat in Tahoe NF boundary2 62,928 0% 1%

Fox Sparrow: Summary of Direct and Indirect Effects

Table 3.03-37 summarizes the overall net effect to fox sparrow habitat from the proposed actions from 

motorized route additions, prohibition of cross country travel, and changes to NFTS.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 241

Table 3.03-37. Fox Sparrow - Summary of Overall Net Direct and Indirect Effects

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres Habitat affected 

by Motorized Cross 

Country Travel

39,639 0 0 0 0 0 0

Proposed Motorized Route Additions to the NFTS

Trend of Effect Negative, most 

impactive

Negative, similar 

to Alts 6, & 7.

No Effect No Effect Negative, next 

most impactive 

following Alt 1.

Negatively shares 

3rd most impacts 

with Alts 2 & 7.

Negative, shares 

3rd most impacts 

with Alts 2 & 6.

ZOI 16% 1% 0% 0% 2% 1% 1%

Changes to NFTS

Wet Weather 

Restrictions

No Effect No Effect No Effect Beneficial from 

reduced 

disturbance

Beneficial from 

reduced 

disturbance

Beneficial from 

reduced 

disturbance

No Effect

Change in Class of 

Vehicles

No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Reopened 

ML 1 

Roads

No Effect No Effect No Effect No Effect No Effect Negative, most 

impactive

Negative, 2nd

most impactive

No Effect

ZOI 0% 0% 0% 0% 1% <1% 0%

Overall Net Effect of 

Proposed Actions

Negatively affects 

fox sparrow habitat 

primarily from 

continued cross 

country travel on 

existing 

unauthorized routes

within 39,639 acres.

Benefits fox 

sparrow habitat

from the ban of 

cross country travel 

on 39,639 acres,; 

slight habitat 

impacts (1%) from 

the addition of 

motorized routes; 

overall reduces

habitat 

fragmentation.

Benefits fox 

sparrow habitat

from the ban of 

cross country travel 

on 39,639 acres.

Benefits fox 

sparrow habitat

from the ban of 

cross country travel 

on 39,639 acres 

Benefits fox 

sparrow habitat

from the ban of 

cross country travel 

on approx. 39,639 

acres, 2nd most 

impactive following 

Alt 1 affecting 

appox. 3% habitat 

from both motorized 

additions and 

reopening ML 1 

roads; overall 

reduces habitat 

fragmentation..

Benefits fox 

sparrow habitat

from the ban of 

cross country travel 

on 39,639 acres; 

slight habitat 

impacts (1%) from 

motorized route 

additions and 

reopened ML 1 

roads; overall 

reduces habitat 

fragmentation..

Benefits fox sparrow 

habitat from the ban 

of cross country 

travel on 39,639 

acres,; slight habitat 

impacts (1%) from 

the addition of 

motorized routes; 

overall reduces 

habitat 

fragmentation.

*Alternative 1 includes existing unauthorized routes that would continue with cross country travel, while all the action alternatives include proposed route additions.Fox Sparrow: 

Cumulative Effects to Habitat in the Analysis Area
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

242 – Tahoe National Forest

Fox Sparrow: Cumulative Effects to Habitat in the Analysis Area

The spatial boundary for analyzing cumulative effects to fox sparrow includes all suitable fox sparrow 

shrubland on the west slope of the Tahoe NF on the Yuba River Ranger District and the American River 

Ranger District. Past and current cumulative effects to fox sparrow include current and historic grazing of 

fox sparrow habitat; loss of habitat through catastrophic wildfires; timber and fuels management where 

cover and forage has been reduced or removed; urban development and expansion within a highly 

checkerboard land ownership pattern; and recreational activities including hunting, camping, and general 

recreation activities including all forms of motorized use including 4-wheel drive vehicles, ATVs, and 

motorcycles.

The Tahoe NF currently has 22 active livestock grazing allotments on the American River and Yuba 

River Ranger Districts, including both cattle and sheep. Tahoe LRMP standards and guidelines, as 

amended by the Sierra Nevada Forest Plan Amendment (USFS 2004), for grazing are generally reducing 

the amount of grazing impacts on rangelands. 

Appendix H (Reasonably Foreseeable Projects and Cumulative Effects) provides a list and 

description of past, present, and reasonably foreseeable projects on NFS and private lands within the 

Tahoe NF boundary. Since 1990, more than 130,000 acres of vegetation management activities have 

occurred on the Tahoe NF. Some, but not all, have resulted in impacts to fox sparrow habitats. Between 

2001 and 2007, over 13,000 acres of forest vegetation and fuels projects were completed, which primarily 

thinned, masticated, and/or burned vegetation to reduce the potential for catastrophic wildfires. Thinning, 

mastication, and under burning treatments may result in some removal of shrubland habitat in the shortterm, but may increase fox sparrow shrubland habitat in the long-term. Between 1994 and 2007, 

approximately 94,000 acres burned on the Tahoe NF, some of which have removed fox sparrow habitat, 

but over time, a large percentage of the burned areas quickly become re-vegetated by shrubland habitats, 

especially on highly productive sites on the west slope of the Tahoe NF. 

Overall Cumulative Effects: Alternative 1 poses the greatest cumulative effects to fox sparrow MIS 

shrubland habitat on the Tahoe NF, where 10,068 acres out of 62,928 acres of fox sparrow habitat would 

be affected within a 200-meter Zone of Influence of existing unauthorized motorized routes. This would

add to existing cumulative effects by approximately 16%. Alternative 1 could contribute to a downward 

trend in fox sparrow habitat effectiveness within shrubland habitat (west slope chaparral) on the Tahoe NF

from continued motor vehicle use on existing unauthorized routes. Alternative 5 would cumulatively 

affect approximately 1,888 acres out of 62,928 acres fox sparrow shrubland habitat or 3% of the Tahoe 

NF fox sparrow shrubland habitat from both the addition of motorized routes and reopened ML 1 roads 

combined. Alternative 5 would result in a small downward trend in habitat effectiveness on the Tahoe NF. 

Alternatives 2, 6, and 7 affect about 629 out of 62,928 acres fox sparrow shrubland habitat or 1% of the 

fox sparrow habitat on the Tahoe NF, and would not alter overall fox sparrow shrubland habitat. 

Alternatives 3 and 4 do not directly or indirectly affect fox sparrow MIS habitat, therefore, no cumulative 

effects would occur from implementation of Alternatives 3 and 4.

Alternatives 4, 5, and 6 would impose wet weather seasonal restrictions on all native surfaced roads 

and motorized trails, where fox sparrow habitat effectiveness would be benefited through the reduced 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 243

disturbance and avoidance when motorized use on native surfaced routes that are seasonally restricted 

during the wet weather season. The change in the class of vehicles would not affect fox sparrow habitat 

for any of the alternatives. Finally, all the action alternatives would prohibit motorized cross country 

travel on 39,639 acres of fox sparrow habitat, where habitat effectiveness would be enhanced through 

reduced disturbance and road-side avoidance. 

Fox Sparrow: Management Direction

Management Indicator Species (MIS) Summary: Summary of Fox Sparrow Status and Trend at the 

Bioregional Scale. The Tahoe NF LRMP (as amended by the SNF MIS Amendment) requires 

bioregional-scale habitat and distribution population monitoring for the fox sparrow; hence, the shrubland 

effects analysis for the Tahoe NF Motorized Travel Management Project must be informed by both habitat 

and distribution population monitoring data. The sections below summarize the habitat and distribution 

population status and trend data for the fox sparrow. This information is drawn from the detailed 

information on habitat and population trends in the Sierra Nevada Forests Bioregional MIS Report 

(USDA Forest Service 2008), which is hereby incorporated by reference.

Habitat Status and Trend. There are currently 922,000 acres of west-slope chaparral shrubland 

habitat on NFS lands in the Sierra Nevada. Within the last decade, the trend is stable. 

Population Status and Trend. The fox sparrow has been monitored in the Sierra Nevada at various 

sample locations by avian point counts and breeding bird survey protocols, including: 1997 to present –

Lassen National Forest (Burnett and Humple 2003, Burnett et al. 2005); 2002 to present - Plumas and 

Lassen National Forests (Sierra Nevada Research Center 2007); on-going monitoring through California 

Partners in Flight Monitoring Sites (CPIF 2002); 1992 to 2005 – Sierra Nevada Monitoring Avian 

Productivity and Survivorship (MAPS) stations (Siegel and Kaschube 2007); and 1968 to present – BBS 

routes throughout the Sierra Nevada (Sauer et al. 2007). These data indicate that fox sparrows continue to 

be present at these sample sites, and current data at the range wide, California, and Sierra Nevada scales 

indicate that, although there may be localized declines in the population trend, the distribution of fox 

sparrow populations in the Sierra Nevada is stable.

Relationship of Project-Level Habitat Impacts to Bioregional-Scale Fox Sparrow Trend. The 

Tahoe NF Travel Management Project would directly, indirectly, and cumulatively affect between 10,068

acres (highest) of fox sparrow shrubland habitat under Alternative 1 and 0 acres (lowest) under 

Alternatives 3 and 4. Based on the acres affected, which range from 0% to 1% of the total Sierra Nevadawide, the Tahoe NF Motorized Travel Management Project would not change the existing trend in the 

habitat, nor would it lead to a change in the distribution fox sparrows across the Sierra Nevada bioregion.

Mountain Quail (Early- and Mid-seral Coniferous Forest Associated 

Species): Affected Environment

The mountain quail was selected as the Management Indicator Species for early- and mid-seral coniferous 

forest (ponderosa pine, Sierran mixed conifer, white fir, red fir, and eastside pine) habitat on the Tahoe 

NF, as amended by in the Sierra Nevada Forests Bioregional EIS. Early-seral coniferous forest habitat is 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

244 – Tahoe National Forest

comprised primarily of seedlings less than 1 inch diameter at breast height (dbh), saplings (1”-5.9” dbh), 

and pole-sized trees (6”-10.9” dbh). Mid-seral coniferous forest habitat is comprised primarily of smallsized trees (11”-23.9” dbh). The mountain quail is found particularly on steep slopes, in open, brushy 

stands of conifer and deciduous forest and woodland, and chaparral; it may gather at water sources in the 

summer, and broods are seldom found more that 0.8 km (0.5 mi) from water (CDFG 2005).

The Tahoe NF Motorized Travel Management project area boundary currently has 89,863 acres of 

early-seral coniferous forest habitat and 402,539 acres of mid-seral coniferous forest habitat. Habitat is 

comprised of various age classes ranging from sparse seeding coniferous forest (1S) to pole size trees 

with dense canopy cover (3D) within the early-seral habitat, and from small tree sizes with sparse cover 

(4S) to small tree sizes with dense cover (4D) in the mid-seral habitat type. Motorized routes within 

mountain quail habitat may lead to changes in behavior and may ultimately result in reduced reproductive 

success for mountain quail.

Mountain quail have the potential to be affected by road and trail-associated factors. The relationship 

between roads and trails associated factors to population trends of the mountain quail is unknown.

Mortality from hunting or trapping: In general, roads facilitate access to hunting of mountain quail. 

Fragmentation, Edge and Microclimate Effects: Roads and motorized trails can also create edge 

effects which may alter microclimates near roads which may enhance habitat for these species or may 

have negligible impacts to their habitat overall.

Disturbance and changes in behavior: Mountain quail may be sensitive to human disturbance. If 

quail roost sites are disturbed by motorized route associated factors, local mountain quail populations may 

be negatively impacted.

Summary of Route associated impacts to mountain quail:

• Mortality from hunting or trapping as facilitated by road and trail access 

• Changes to habitat microclimate associated with the edge induced by roads or motorized trails 

• Changes in behavior that may lead to loss of reproductive success due to trail and road associated 

factors.

Mountain Quail: Environmental Consequences

Mountain Quail: Indicators used to Measure Effects

The habitat factor used in this analysis for the action alternatives was the amount of early- and mid-seral

coniferous forest habitat that fell within the 200-meter Zone of Influence of proposed motorized route 

additions to the NFTS. For Alternative 1, no action, the amount of early- and mid-seral coniferous forest 

habitat that fell within the 200-meter Zone of Influence of existing unauthorized routes was determined. 

Each alternative was compared to determine the proportion of habitat directly and indirectly affected in 

relation to the amount of early- and mid-seral coniferous forest habitat available at the Sierra Nevadawide scale.

The Tahoe NF Motorized Travel Management project area boundary currently has 89,863 acres of 

early-seral coniferous forest habitat and 402,539 acres of mid-seral coniferous forest habitat. Habitat is 

comprised of various age classes ranging from sparse seeding coniferous forest (1S) to pole size trees 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 245

with dense canopy cover (3D) within the early-seral habitat, and from small tree sizes with sparse cover 

(4S) to small tree sizes with dense cover (4D) in the mid-seral habitat type. Motorized routes within 

mountain quail habitat may lead to changes in behavior and may ultimately result in reduced reproductive 

success for mountain quail.

Mountain Quail: Direct and Indirect Effects

Cross Country Travel: Under Alternative 1, cross country travel would continue, affecting 344,961 acres 

of early-seral and mid-seral coniferous forest habitats combined, potentially causing reduced habitat 

effectiveness through disturbance, avoidance, and abandonment for the mountain quail. For the action 

alternatives, cross country travel would be prohibited on 344,961 early- and mid-seral coniferous forest 

acres, where disturbance, avoidance, abandonment would be reduced or eliminated.

Additions to the NFTS: Tables 3.03-38 and 3.03-39 display the proportion of early- and mid-seral

coniferous forest affected by the alternatives within a 200-meter Zone of Influence of motorized routes. 

Based on the amount of early- and mid-seral coniferous forest habitat affected within a 200-meter Zone of 

Influence of motorized routes, Alternative 1, no action, results in the greatest amount of both early-seral

(26,989 acres or about 5% of Sierra Nevada-wide habitat) and mid-seral (76,482 acres or about 3% of 

Sierra Nevada-wide habitat) coniferous habitat affected. At the scale of the Tahoe NF, Alternative 1 results 

in a moderate risk (30%) to habitat security within early-seral habitat, and a low risk (19%) to habitat 

security for the mountain quail within mid-seral habitat.

For the action alternatives, Alternative 5 result in the next greatest amount of both early- and midseral habitat affected by proposed motorized route additions, which affects 1,797 acres (0.3% of Sierra 

Nevada-wide habitat) and 5,325 acres (0.2% of Sierra Nevada-wide habitat), respectively. The remaining 

action alternatives affect between 0 acres to 1,797 acres of early-seral habitat; and between 0 acres to 

5,325 acres of mid-seral conifer habitat. For all the action alternatives, early- and mid-seral habitat 

affected by motorized routes results in a low risk to habitat security for mountain quail at the Sierra-wide 

scale and at the Tahoe NF scale.

Table 3.03-38. Proportion of Mountain Quail Early-seral Coniferous Forest MIS habitat within a 200-meter 

“Zone of Influence” of Proposed Motorized route additions to the NFTS

Mountain Quail MIS Habitat Total Habitat 

Acres

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Acres Early-seral Coniferous 

Forest

26,989 899 0 719 1,797 1,797 0

Proportion of Sierra Nevada 

Habitat 

546,000 5% 0.2% 0% 0.1% 0.3% 0.3% 0%

Habitat Security Risk in Sierra Nevada Low Low Low Low Low Low Low

Proportion of Tahoe NF Habitat2 89,863 30% 1% 0% 0.8% 2% 2% 0%

Habitat Security Risk in Tahoe NF Moderate Low Low Low Low Low Low

*

Alternative 1 includes existing unauthorized routes with continued cross country travel.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

246 – Tahoe National Forest

Table 3.03-39. Proportion of Mountain Quail Mid-seral Coniferous Forest MIS habitat within a 200-meter 

“Zone of Influence” of Proposed Motorized route Additions to the NFTS

Mountain Quail MIS Habitat Total Habitat 

Acres

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Acres Mid-seral Coniferous Forest 76,482 5,325 0 2,662 5,325 0 2,662

Proportion of Sierra Nevada Habitat 2,766,000 2.8% 0.2% 0% 0.1% 0.2% 0% 0.1%

Habitat Security Risk in Sierra Nevada Low Low Low Low Low Low Low

Proportion of Tahoe NF Habitat 402,539 19% 1.3% 0% 0.7% 1.3% 0% 0.7%

Habitat Security Risk in Tahoe NF Low Low Low Low Low Low Low

*

Alternative 1 includes existing unauthorized routes with continued cross country travel.

Changes to the NFTS: Tables 3.03-40 and 3.03-41 displays the proportion of early- and mid-seral

coniferous forest affected by the alternatives within a 200-meter Zone of Influence of reopened 

Maintenance Level 1 (ML 1) roads. Alternative 5 results in the greatest amount of both early-seral (2,696 

acres or about 0.5% of Sierra Nevada-wide habitat) and mid-seral (4,025 acres or about 0.1% of Sierra 

Nevada-wide habitat) coniferous habitat reduced habitat effectiveness from reopened ML 1 roads.

Alternative 6 follows Alternative 5, and affects 899 acres (0.2% Sierra-wide habitat) of early-seral habitat 

and does not affect any mid-seral habitat. Both Alternatives 5 and 6 would result in a low risk to habitat 

security for mountain quail at the bioregional and at the Forest scale. The remaining alternatives do not 

propose to reopen any ML 1 roads, and therefore would not affect early- and mid-seral habitat suitable for 

the mountain quail. The changes in class of vehicle and changes in wet weather seasonal restrictions are 

analyzed under “Summary of Effects Common to All Species.”

Table 3.03-40. Proportion of Mountain Quail Early-seral Coniferous Forest MIS habitat within a 200-meter 

“Zone of Influence” of Reopened Maintenance Level 1 Roads

Mountain Quail MIS Habitat Total Habitat 

Acres

Alternatives

1*, 2, 3, 4, 7

Alt 5 Alt 6

Acres Early-seral Coniferous Forest within ZOI 0 2,696 899

Proportion of Sierra Nevada Habitat 546,000 0% 0.5% 0.2%

Habitat Security Risk in Sierra Nevada No Risk Low Low

Proportion of Tahoe NF Habitat2 89,863 0% 3% 1%

Habitat Security Risk in Tahoe NF No Risk Low Low

*

Alternative 1 includes existing unauthorized routes with continued cross country travel.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 247

Table 3.03-41. Proportion of Mountain Quail Mid-seral Coniferous Forest MIS habitat within a 200-meter 

“Zone of Influence” of Reopened Maintenance Level 1 Roads

Mountain Quail MIS Habitat Total Habitat 

Acres2 Alternatives 11

, 2 3, 

4, 6, 7

Alt 5

Acres Mid-seral Coniferous Forest within ZOI2 0 4,025

Proportion of Sierra Nevada Habitat 2,766,000 0% 0.1%

Habitat Security Risk in Sierra Nevada No Risk Low

Proportion of Tahoe NF Habitat 402,539 0% 1%

Habitat Security Risk in Tahoe NF No Risk Low

1

Alternative 1 includes existing unauthorized routes with continued cross country travel.

2 The Zone of Influence within 200 meters of motorized routes includes both NFS and non-NFS lands within the boundary of the 

TNF due to the complex checkerboard pattern. The proportion of habitat affected likley over-represents the actual amount of 

habitatat affected on NFS lands.

Mountain Quail: Summary of Direct and Indirect Effects 

Table 3.03-42 summarizes the overall net effect to mountain quail early- and mid-seral habitat from the 

proposed actions from cross country travel, motorized route additions to the NFTS, and changes to the 

NFTS.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

248 – Tahoe National Forest

Table 3.03-42. Mountain Quail - Summary of Overall Net Direct and Indirect Effects

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres Habitat affected by 

Motorized Cross Country Travel

344,961 0 0 0 0 0 0

Proposed Motorized Route Additions to the NFTS

Trend of Effect Negative, most 

impactive

Negative, 3rd most 

impactive

No Effect Negative, impacts 

similar to 

Alternatives 6 & 7

Negative, next 

most impactive 

following Alt 1.

Negative, 

impacts similar 

to Alternative 2 

& 7.

Negative,

impacts similar to 

Alternatives 4 & 

6.

ZOI (early-seral habitat 30% 1% 0% <1%% 2% 1% 0%

ZOI (mid-seral habitat) 19% 1% 0% 1% 1% 0% 1%

Changes to NFTS

Wet Weather Restrictions No Effect No Effect No Effect Beneficial from 

reduced 

disturbance

Beneficial from 

reduced 

disturbance

Beneficial 

from reduced 

disturbance

No Effect

Change in Class of Vehicles No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Reopened ML 

1 Roads

Trend of Effect No Effect No Effect No Effect No Effect Negative, most 

impactive

Negative, 2nd

most impactive

No Effect

ZOI (early-seral) 0% 0% 0% 0% 3% 1% 0%

ZOI (mid-seral) 0% 0% 0% 0% 1% 0% 0%

Overall Net Effect of Proposed 

Actions

Most impactive of 

all alternatives. 

Negatively affects 

19 to 30% 

mountain quail

habitat primarily 

from continued 

cross country travel 

on existing 

unauthorized 

routes within 

344,961 acres.

Benefits mountain 

quail habitat from 

the ban of cross 

country travel on 

344,961 acres; 

slight habitat 

impacts (1% each 

early- and midseral) from the 

addition of 

motorized routes.

Benefits mountain 

quail habitat from 

the ban of cross 

country travel on 

344,961 acres.

Benefits mountain 

quail habitat from 

the ban of cross 

country travel on 

344,961 acres; 

slight negative 

impacts (1%) to 

mid-seral habitat 

from motorized 

route additions.

Benefits mountain 

quail habitat from 

the ban of cross 

country travel on 

approx. 344,961

acres, 2nd most 

impactive following 

Alt 1 affecting 

between 2 to 5% 

habitat from both 

motorized additions 

and reopening ML 

1 roads.

Benefits 

mountain quail 

habitat from the 

ban of cross 

country travel 

on 344,961 

acres; slight 

habitat impacts 

(2%) from 

motorized route 

additions and 

reopened ML 1 

roads.

Benefits 

mountain quail

habitat from the 

ban of cross 

country travel on 

344,961 acres, 

slight impacts 

(1%) to mid-seral

habitat from 

motorized route 

additions.

*Alternative 1 includes existing unauthorized routes with continued cross country travel, while all the action alternatives include proposed route additions.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 249

Mountain Quail: Cumulative Effects to Habitat in the Analysis Area

The spatial boundary for analyzing cumulative effects to mountain quail includes mid and early-seral

coniferous forest habitat within the boundary of the Tahoe NF. Past and current cumulative effects to 

mountain quail include current and historic grazing of mountain quail habitat; loss of early- and mid-seral

conifer forest habitat through catastrophic wildfires; timber and fuels management where cover and 

forage has been reduced or removed; urban development and expansion within a highly checkerboard 

land ownership pattern; and recreational activities including hunting, camping, and general recreation 

activities including all forms of motorized use including 4 wheeled drive vehicles, ATVs, and 

motorcycles.

The Tahoe NF currently has 22 active livestock grazing allotments on the west side of the Tahoe NF, 

including both cattle and sheep. Tahoe LRMP standards and guidelines, as amended by the Sierra Nevada 

Forest Plan Amendment (USFS 2004), for grazing are generally reducing the amount of grazing impacts 

on rangelands. 

Appendix H (Reasonably Foreseeable Projects and Cumulative Effects) provides a list and 

description of past, present, and reasonably foreseeable projects on NFS and private lands within the 

Tahoe NF boundary. Some, but not all, of these activities will contribute to impacts to the mountain quail 

habitat within the Tahoe NF boundary. Since 1990, more than 130,000 acres of vegetation management 

activities have occurred on the Tahoe NF. Some, but not all, have resulted in impacts to mountain quail 

habitats. Between 2001 and 2008, approximately 17,000 acres of forest vegetation and fuels projects were 

completed, which primarily thinned, masticated, and/or burned vegetation to reduce the potential for 

catastrophic wildfires. These treatments generally do not increase forage conditions for quail because they 

do not usually result in reducing the canopy cover below 40%, except for group selection harvest 

treatments on the Sierraville RD. Group selection harvests are expected to increase forage condition and 

increase forest structural diversity. These thinning treatments may result in the short-term reduction in 

cover for mountain quail, though it is expected that in the longer term, habitat will be protected by 

reducing wildfire risk. Between 1994 and 2008, approximately 95,000 acres burned on the Tahoe NF, 

some of which have removed mountain quail habitat. 

Currently, there is a high demand for recreational use on the Tahoe NF due to its close proximity to 

urban centers. The Tahoe NF provides a wide variety of recreational experiences including developed and 

dispersed camping, hiking, fishing, hunting, wildlife viewing, winter sports activities (downhill skiing, 

cross country skiing, snowmobiling), summer OHV use, and a variety of other non-motorized use 

(equestrian use and mountain biking). Recreational use on the Tahoe NF has significantly increased 

compared to the past 20 to 30 years. Because of the proximity to urban areas and population growth, 

increased recreational use on the Tahoe NF is expected to continue to increase in the future including

camping, hiking, fishing, wildlife viewing, hunting, and OHV use. Generally, the increase in recreational 

use on the Tahoe NF has the potential to cause an increase in negative interactions between humans and 

mountain quail. Future increase in recreational use on the Tahoe NF is expected, and therefore, increased 

disturbance to mountain quail would be expected, particularly during the summer months. Table 3.03-43
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

250 – Tahoe National Forest

summarizes a list of the reasonably foreseeable future projects and their potential direct, indirect, and 

cumulative impacts.

Table 3.03-43. Direct, Indirect, and Cumulative Impact of Reasonably Foreseeable Future Projects

Project type Number of 

Projects

Direct and Indirect Impact Overall Cumulative Impact

Vegetation 

management/fuels reduction 

projects – thinning, group 

select, 

~30 • Short-term disturbance from 

harvest activities, 

• changes in cover, foraging habitat 

enhancement in oak habitats.

• Long-term beneficial 

cumulative effects by reduced 

risk of habitat loss from high 

severity wildfires.

Aspen enhancement 8 • Cover and forage habitat 

enhancement 

• Short-term adverse impacts during 

implemtation

• Long-term beneficial 

cumulative effects through 

improved forage and cover 

production

Hazard tree removal 4 Minimal impact. Short-term 

disturbance during harvest.

None to minimal cumulative 

impact

Salvage Fire Burned Trees 2 Minimal impact. Short-term 

disturbance during harvest.

None to minimal cumulative 

impact

Fish passage construction 

project

1 Short-term disturbance during 

project implementation.

No cumulative impact

Mastication, site prep and 

release of small trees, and 

prescribed burns

~20 • Short-term disturbance during 

project implementation

• Various site-specific effects.

• Long-term beneficial 

cumulative beneficial effects 

depending on site-specific 

conditions

Watershed Restoration 

(Carman II and Perazzo)

2 • Short-term disturbance during 

implementation. 

• Improve foraging habitat adjacent 

to early- and mid-seral coniferous 

forest habitat. 

Beneficial cumulative impact 

by improving long-term forage 

quality.

Special Use permit renewal 4 N/A administrative action None

Non-motorized Trail 

development

2 Short-term disturbance during trail 

construction, some increased public 

use may increase disturbance.

Slight increase in cumulative 

impact.

Designate Energy Corridor 1 N/A programmatic administrative 

action

Unknown, site-specific 

cumulative impacts may occur 

depending on location of the 

corridor.

Cumulative Effects Conclusion

Alternative 1 adds the greatest amount to existing cumulative impacts by affecting 30% early-seral

coniferous forest habitat (26,989 acres out of 89,863 TNF habitat acres) and 19% mid-seral coniferous 

forest habitat (76,482 out of 402,539 TNF habitat acres on the Tahoe NF. Alternative 5 follows, by 

affecting 2% early-seral and 1% mid-seral coniferous forest habitats, from proposed motorized route 

additions to the NFTS within a 200-meter Zone of Influence. The remaining action alternatives affect 

between 0 and 1% early- and mid-seral coniferous forest habitat combined. Based on the small percentage 

of habitat affected by the action alternatives, the Tahoe NF Motorized Travel Management Project would

not alter the existing trend in early- and mid-seral coniferous forest habitat important for the mountain 
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Tahoe National Forest – 251

quail. Alternative 1 may cause a downward trend in mountain quail habitat and may affect the distribution 

of the species on the Tahoe NF. 

Alternatives 4, 5, and 6 would impose wet weather seasonal restrictions on all native surfaced roads 

and motorized trails, where mountain quail habitat effectiveness would be benefited through the reduced 

disturbance and avoidance when motorized use on native surfaced routes that are seasonally restricted 

during the wet weather season. The change in the class of vehicles would not affect mountain quail 

habitat for all of the proposed alternatives. Finally, all the action alternatives would prohibit motorized 

cross country travel on 34,961 acres of early- and mid-seral coniferous forest habitat, where mountain 

quail habitat effectiveness would be enhanced through reduced disturbance and avoidance. 

Summary of Mountain Quail Status and Trend at the Bioregional Scale. The Tahoe NF LRMP 

(as amended by the SNF MIS Amendment) requires bioregional-scale habitat and distribution population 

monitoring for the mountain quail; hence, the early- and mid-seral coniferous forest effects analysis for 

the Tahoe NF Motorized Travel Management Project must be informed by both habitat and distribution 

population monitoring data. The sections below summarize the habitat and distribution population status 

and trend data for the mountain quail. This information is drawn from the detailed information on habitat 

and population trends in the SNF Bioregional MIS Report (USDA Forest Service 2008), which is hereby 

incorporated by reference.

Habitat Status and Trend. There are currently 546,000 acres of early-seral and 2,766,000 acres of 

mid-seral coniferous forest (ponderosa pine, Sierran mixed conifer, white fir, and red fir) habitat on NFS

lands in the Sierra Nevada. Within the last decade, the trend for early-seral is slightly decreasing (from 

9% to 5% of the acres on NFS lands) and the trend for mid-seral is slightly increasing (from 21% to 25% 

of the acres on NFS lands). 

Population Status and Trend. The mountain quail has been monitored in the Sierra Nevada at 

various sample locations by hunter survey, modeling, and breeding bird survey protocols, including 

California Department of Fish and Game hunter survey, modeling, and hunting regulations assessment 

(CDFG 2004a, CDFG 2004b) and 1968 to present – BBS routes throughout the Sierra Nevada (Sauer et 

al. 2007). These data indicate that mountain quail continue to be present across the Sierra Nevada, and 

current data at the range wide, California, and Sierra Nevada scales indicate that the distribution of 

mountain quail populations in the Sierra Nevada is stable. 

Relationship of Project-Level Habitat Impacts to Bioregional-Scale Mountain Quail Trend. The 

Tahoe NF Motorized Travel Management Project would affect 26,989 acres (5% of Sierra Nevada wide 

habitat) of early-seral coniferous forest and 76,482 acres (3% of Sierra Nevada-wide habitat) of mid-seral

coniferous forest habitat important to mountain quail under Alternative 1 from the combined addition of 

motorized routes and reopened ML 1 roads. The action alternatives would affect between 0 acres and 

4,493 acres (Alternatives 3 and 7- lowest to Alternative 5 - highest) of early-seral coniferous habitat, and 

between 0 acres and 9,350 acres (Alt 3- lowest to Alt 5 – highest) of mid-seral coniferous forest habitat

from the total motorized routes added and reopened ML 1 roads. All the action alternatives result in a low 

percentage of total early- and mid-seral habitat (less than 1 % of Sierra Nevada-wide mid and early-seral

habitat) affected by the addition motorized routes and reopened ML 1 roads combined. Alternative 1 does 
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252 – Tahoe National Forest

not prohibit cross country travel, including continued use of unauthorized routes, where approximately 3-

5% early- and mid-seral coniferous forest combined would be affected at the Sierra Nevada-wide scale. 

Based upon the low amount of habitat affected, the Tahoe NF Motorized Travel Management Project 

would not alter the existing trend in early-seral and mid-seral coniferous habitats, nor would it lead to a 

change in the distribution of mountain quail across the Sierra Nevada bioregion.

Sooty (Blue) Grouse (Late-Seral Open Canopy Coniferous Forest): 

Affected Environment

Habitat/Species Relationship

The sooty grouse was selected as the MIS for late-seral open canopy coniferous forest (ponderosa pine, 

Sierran mixed conifer, white fir, red fir, and eastside pine) habitat in the Sierra Nevada. This habitat is 

comprised primarily of medium/large trees (equal to or greater than 24 inches dbh) with canopy closures 

less than 40%. Sooty grouse occurs in open, medium to mature-aged stands of fir, Douglas-fir, and other 

conifer habitats, interspersed with medium to large openings, and available water, and occupies a mixture 

of mature habitat types, shrubs, forbs, grasses, and conifer stands (CDFG 2005). Empirical data from the 

Sierra Nevada indicate that sooty Grouse hooting sites are located in open, mature, fir-dominated forest, 

where particularly large trees are present (Bland 2006). 

Blue grouse have the potential to be affected by road and motorized trail-associated factors. The 

relationship between road and motorized trail associated factors to population trends of the blue grouse is 

unknown.

Mortality from hunting or trapping: In general, roads facilitate access to hunting of blue grouse.

Fragmentation, Edge and Microclimate Effects: Roads and motorized trails can also create edge 

effects which may alter microclimates near roads which may enhance habitat for these species or may 

have negligible impacts to their habitat overall.

Disturbance and changes in behavior: Blue grouse may be sensitive to human disturbance. If blue 

grouse roost sites are disturbed by route associated factors, local blue grouse populations may be 

negatively impacted.

Summary of Route associated factors to blue grouse:

• Mortality from hunting or trapping as facilitated by road and motorized trail access 

• Changes to habitat microclimate associated with the edge induced by roads or motorized trails 

• Changes in behavior that may lead to loss of reproductive success due to trail and road associated 

factors.

The project area (Tahoe NF boundary NFS and non-NFS lands) currently has 35,389 acres of lateseral open canopy coniferous forest habitat. This habitat is comprised of size classes 5S (medium/large 

trees with sparse canopy cover and 5 (medium/large trees with open canopy cover).
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 253

Sooty Grouse (Blue Grouse): Environmental Consequences

Indicators used to Measure Effects

Cross Country Travel: The acres of cross country travel that would be prohibited within late-seral open 

canopy coniferous forest habitats are determined for each of the alternatives.

Additions to the NFTS: For the proposed alternatives, the Zone of Influence of disturbance used in 

this analysis was the amount of late-seral open canopy coniferous forest that fell within a 200 meter Zone 

of Influence of proposed motorized routes. The No Action Alternative (Alternative 1) was analyzed by 

determining the amount of late-seral open canopy coniferous forest that fell within a 200 meter Zone of 

Influence of existing unauthorized routes. Each alternative was compared to determine the proportion of 

habitat directly and indirectly affected in relation to the amount of late-seral coniferous open canopy 

forest habitat available at the Sierra Nevada-wide scale.

Establishment of “Open Areas”: Establishment of “Open Areas” is discussed under “Summary of 

Effects Common to All Species.”

Changes to the NFTS: The Zone of Influence of reopened Maintenance Level 1 roads is determined 

for each alternative within late-seral open canopy coniferous forest. The changes in class of vehicle and 

changes in seasonal restrictions are analyzed under “Summary of Effects Common to All Species.”

Direct and Indirect Effects to Habitat

Cross Country Travel. Under Alternative 1, cross country travel would not be prohibited, potentially 

affecting 17,178 acres of sooty grouse habitat within late-seral open canopy coniferous forest, potentially 

causing disturbance and reducing sooty grouse habitat effectiveness. For the action alternatives, cross 

country travel would be prohibited on 17,178 acres, where disturbance, avoidance, and disruption would 

be reduced or eliminated for the sooty grouse. 

Additions to the NFTS. Alternative 1 affects the greatest amount of late-seral open canopy 

coniferous forest with a 200-meter Zone of Influence of existing motorized unauthorized routes, which 

would continue in association with cross country travel. Alternative 1 affects 4,247 acres (6% of Sierra 

Nevada-wide habitat, 12% Tahoe NF habitat) of sooty grouse habitat (Table 3.03-44) where sooty grouse 

habitat security risk would be greatest from disturbance or reduced habitat quality from motorized 

activities. Alternative 5 would result in the next greatest amount of sooty grouse habitat affected by the 

addition of motorized routes (708 acres or 1% of Sierra-wide habitat, 2% Tahoe NF habitat). Alternatives 

2 and 6 would similarly affect 354 acres of sooty grouse habitat (0.5% of Sierra Nevada-wide habitat, 1% 

Tahoe NF habitat) from additions to the NFTS. Alternatives 4 and 7 would affect approximately 194 

suitable sooty grouse habitat acres (0.3% Sierra Nevada habitat, 0.6% Tahoe NF habitat). Alternative 3 

does not propose to add any motorized routes to the NFTS, therefore, sooty grouse habitat on the Tahoe 

NF would not be affected by this project.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

254 – Tahoe National Forest

Table 3.03-44. Proportion of Sooty (Blue) Grouse Late-seral Open Canopy Coniferous Forest MIS habitat 

within a 200-meter “Zone of Influence” of Proposed Motorized route Additions to the NFTS

Sooty Grouse MIS Habitat Alt 1* Alts 2, 6, Alt 3 Alt 4, 7 Alt 5

Acres Sooty Grouse Habitat - Late-seral Open Coniferous 

Forest within ZOI

4,247 354 0 194 708

Proportion of Sierra Nevada Habitat 75,000 6% 0.5% 0% 0.3% 1%

Habitat Security Risk in Sierra Nevada Low Low No Risk Low

Proportion of Tahoe NF Habitat2 35,389 12% 1% 0% 0.6% 2%

Habitat Security Risk in Tahoe NF Low Low Low Low

*

Alternative 1 includes the Zone of Influence within 200 meters of existing motorized unauthorized routes with continued cross 

country travel, while all the action alternatives include the Zone of Influence of motorized route additions.

Reopened Maintenance Level 1 Roads: Alternative 5 affects the greatest amount of late-seral open 

canopy coniferous forest with a 200-meter Zone of Influence of reopened Maintenance Level 1 roads. 

Alternative 5 affects 197 acres (0.3% of Sierra Nevada-wide habitat, 0.6% Tahoe NF habitat) of sooty 

grouse habitat (Table 3.03-45). The remaining alternatives do not propose to reopen any ML 1 roads and 

therefore, sooty grouse habitat on the Tahoe NF would not be affected by implementing Alternatives 1, 2, 

3, 4, 6, or 7.

Table 3.03-45. Proportion of Sooty (Blue) Grouse Late-seral Open Canopy Coniferous Forest MIS habitat 

within a 200-meter “Zone of Influence” of Reopened Maintenance Level 1 Roads

Sooty Grouse MIS Habitat Alternatives 1*, 2, 3, 4, 6, 7 Alt 5

Acres Sooty Grouse Habitat - Late-seral Open Coniferous Forest 

within ZOI

0 197

Proportion of Sierra Nevada Habitat 75,000 0% 0.3%

Habitat Security Risk in Sierra Nevada No Risk Low

Proportion of Tahoe NF Habitat within ZOI 35,389 0% 0.6%

Habitat Security Risk in Tahoe NF No Risk Low

* Alternative 1 includes the Zone of Influence within 200 meters of existing motorized unauthorized routes with continued cross 

country travel, while all the action alternatives include the Zone of Influence of reopened ML 1 roads.

Summary of Direct and Indirect Effects

Table 3.03-46 summarizes the overall net effect to sooty grouse habitat from the proposed actions from 

motorized route additions to the NFTS, prohibition of cross country travel, wet weather restrictions, and 

seasonal closures.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 255

Table 3.03-46. Sooty Grouse- Summary of Overall Net Direct and Indirect Effects 

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country 

Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres Cross 

Country Travel 

Prohibited

0 17,178 17,178 17,178 17,178 17,178 17,178

Establishment of “Open Areas” No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Motorized Route 

Additions to the 

NFTS

Trend of Effect Negative, most 

impactive

Negative, 3rd

most impactive

No Effect Negative, 

impacts similar to 

Alternative 6 & 7

Negative, next 

most impactive 

following Alt 1.

Negative, 

impacts similar to 

Alternative 2 & 7.

Negative,

impacts similar 

to Alts 4 & 6.

Acres Affected in 

ZOI

4,247 353 0 194 708 353 194

Percentage Habitat 

Affected in ZOI

12% 1% 0% <1% 2% 1% <1%

Change to 

the NFTS

Change in Season of Use

No Effect No Effect No Effect

Beneficial from 

reduced 

disturbance

Beneficial from 

reduced 

disturbance

Beneficial from 

reduced 

disturbance

No Effect

Change in Class of Vehicle No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Reopened ML 1 

Roads

Trend of 

Effect

No Effect No Effect No Effect No Effect Negative, most 

impactive

No Effect No Effect

ZOI 0% 0% 0% 0% <1% 0% 0%

Amendment to Forest Plan No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Overall Net Effect of Proposed Actions Most impactive 

of all alternatives

Negatively 

affects 12% 

sooty grouse 

habitat primarily 

from continued 

cross country 

travel on existing 

unauthorized 

routes within 

17,178 acres..

Benefits habitat 

from the ban of 

cross country 

travel on 17,178 

acres; slight 

habitat impacts 

(1%) from 

motorized route 

additions; shares 

3rd most impacts 

with Alt 6; overall 

reduces habitat 

fragmentation..

Benefits habitat 

the most from 

the ban of cross 

country travel on 

17,178 acres; 

and no motorized 

additions or 

reopened ML 1 

roads; overall 

reduces habitat 

fragmentation..

Benefits habitat 

from the ban of 

cross country 

travel on 17,178 

acres; minimal 

negative impacts 

(<1%) to sooty 

grouse habitat 

from motorized 

route additions, 

shares 4th most 

impacts with Alt 

7; overall 

reduces habitat 

fragmentation..

Benefits habitat 

from the ban of 

cross country 

travel on approx. 

17,178 acres, 2nd

most impactive 

following Alt 1 

affecting 2% 

habitat from 

motorized 

additions; overall 

reduces habitat 

fragmentation..

Benefits habitat 

from the ban of 

cross country 

travel on 17,178 

acres; slight 

habitat impacts 

(1%) from 

motorized route 

additions, hsares 

3rd most impacts 

with Alt 2; overall 

reduces habitat 

fragmentation..

Benefits habitat 

from the ban of 

cross country 

travel on 17,178 

acres; minimal 

negative impacts 

(<1%) to sooty 

grouse habitat 

from motorized 

route additions, 

shares 4th most 

impacts with Alt 

4; overall 

reduces habitat 

fragmentation..

*Alternative 1 includes existing unauthorized routes with continued cross country travel, while all the action alternatives, while all the action alternatives include the Zone of Influence of 

motorized route additions.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

256 – Tahoe National Forest

Cumulative Effects to Sooty Grouse Habitat 

The spatial boundary for analyzing cumulative effects to blue grouse includes all late-seral open canopy 

coniferous forest habitat within the boundary of the Tahoe NF. Past and current cumulative effects to blue 

grouse include current and historic grazing of sooty grouse habitat; loss of habitat through catastrophic 

wildfires; timber and fuels management where cover and forage has been reduced or removed; urban 

development and expansion within a highly checkerboard land ownership pattern; and recreational 

activities including hunting, camping, and general recreation activities including all forms of motorized 

use including 4 wheeled drive vehicles, ATVs, and motorcycles.

The Tahoe NF currently has 31 active livestock grazing allotments including both cattle and sheep. 

Tahoe LRMP standards and guidelines, as amended by the Sierra Nevada Forest Plan Amendment (USFS 

2004), for grazing are generally reducing the amount of grazing impacts on rangelands. 

Appendix H (Reasonably Foreseeable Projects and Cumulative Effects) provides a list and 

description of past, present, and reasonably foreseeable projects on NFS and private lands within the 

Tahoe NF boundary. Some, but not all, of these activities would contribute to impacts to the sooty grouse 

within the Tahoe NF boundary. Since 1990, more than 130,000 acres of vegetation management activities 

have occurred on the Tahoe NF. Some, but not all, have resulted in impacts to blue grouse habitats. 

Between 2001 and 2008, approximately 17,000 acres of forest vegetation and fuels projects were 

completed, which primarily thinned, masticated, and/or burned vegetation to reduce the potential for 

catastrophic wildfires. These treatments may not affect habitat for sooty grouse because they generally 

retain at least 40% canopy cover, except for group selection harvest treatments for HFQLG projects on 

the Sierraville RD. Group selection harvests are expected to increase forage condition and increase forest 

structural diversity. Some thinning treatments may result in the short-term reduction in cover for sooty

grouse, though it is expected that in the longer term, habitat will be protected by reducing wildfire risk. 

Many recent, current, and future vegetation and fuels reduction projects are improving blue grouse habitat 

within aspen habitats which are designed to enhance wildlife habitat diversity and foraging condition. 

Aspen habitats are important for sooty grouse. Between 1994 and 2008, approximately 95,000 acres 

burned on the Tahoe NF, some of which have removed sooty grouse habitat. 

Currently, there is a high demand for recreational use on the Tahoe NF due to its close proximity to 

urban centers. The Tahoe NF provides a wide variety of recreational experiences including developed and 

dispersed camping, hiking, fishing, hunting, wildlife viewing, winter sports activities (downhill skiing, 

cross country skiing, snowmobiling), summer OHV use, and a variety of other non-motorized use 

(equestrian use and mountain biking). Recreational use on the Tahoe NF has significantly increased 

compared to the past 20 to 30 years. Because of the proximity to urban areas and population growth, 

increased recreational use on the Tahoe NF is expected to continue to increase in the future including 

camping, hiking, fishing, wildlife viewing, hunting, and OHV use. Increases in recreational use in the 

near future are expected, and therefore, increased disturbance, displacement, avoidance, or illegal 

poaching to sooty grouse could be expected, particularly during the summer months. Table 3.03-47 lists 

all the reasonably foreseeable future actions, including fuels, vegetation, recreation, range allotment 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 257

plans, non-motorized trail development, and special use permit re-issuances, and summarizes cumulative 

impacts to sooty grouse.

Table 3.03-47. Sooty Grouse Direct, Indirect, and Cumulative Impact of Reasonably Foreseeable Future Projects

Project type Number of 

Projects

Direct and Indirect Impacts to 

Sooty Grouse

Overall Cumulative Impacts

Vegetation management/

fuels reduction –

thinning, group select, 

and aspen enhancement

~30 Short-term disturbance from 

harvest activities, changes in 

cover, foraging and reproductive 

habitat enhancement in aspen and 

oak habitats. 

Long-term beneficial cumulative 

effects by reduced risk of habitat 

loss from high severity wildfires.

Aspen enhancement 8 Short-term disturbance during 

implementation.

Long-term cover and forage habitat 

improvement

Long-term beneficial cumulative 

effects from improved habitat 

conditions

Mastication, site prep, 

and release of small 

trees, and prescribed 

burning.

~20 Short-term disturbance during 

implementation.

Site-specific effects vary from 

beneficial to negative.

Cumulative impacts vary from no 

cumulative impact to slight 

increase in cumulative impact.

Hazard tree removal 4 Minimal impact. Short-term 

disturbance during harvest.

None to minimal cumulative impact

Fish passage 

construction project

1 Short-term disturbance during 

project implementation.

No cumulative impact

Watershed Restoration 

(Carman II and Perazzo)

2 Short-term disturbance during 

implementation. Improve riparian 

and meadow habitat quality used 

for forage and reproduction.

Beneficial cumulative impact by 

improving long-term forage quality.

Special Use permit 

renewal

4 N/A administrative action None

Non-motorized Trail 

development

2 Short-term disturbance during trail 

construction, some increased 

public use may increase 

disturbance.

Slight increase in cumulative 

impact.

Designate Energy 

Corridor

1 N/A programmatic administrative 

action

Unknown, site-specific cumulative 

impacts may occur depending on 

location of the corridor.

Cumulative Effects Conclusion

Alternative 1 poses the greatest cumulative effects to sooty grouse MIS late-seral open canopy coniferous 

habitat on the Tahoe NF where 12% (4,247 acres out of 35,389 Tahoe NF habitat acres) sooty grouse 

habitat would be affected within a 200-meter Zone of Influence of existing unauthorized motorized routes 

that would continue with cross country travel. Alternative 5 would cumulatively add impacts on 

approximately 708 acres out of 35,389 acres sooty grouse habitat or approximately 2% of the Tahoe NF 

late-seral open canopy coniferous habitat from the addition of motorized routes and from reopened ML 1 

roads. Alternatives 2, 4, 6, and 7 would negatively add 1% or less (194 to 353 acres out of 35, 389 acres 

Tahoe NF habitat) to existing cumulative impacts from the addition of motorized routes. Alternative 3 

does not directly or indirectly affect sooty grouse habitat, and therefore no cumulative impacts would be 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

258 – Tahoe National Forest

added under this alternative. None of the action alternatives would alter the existing trend in late-seral

open canopy coniferous forest habitat. 

The change is the class of vehicles would have no effect to sooty grouse habitat, since the change in 

class of vehicles on existing motorized routes would generally not alter sooty grouse habitat condition. 

Wet weather seasonal restrictions under Alternatives 4, 5, and 6 on all native surfaced roads and 

motorized trails would benefit sooty grouse habitat effectiveness through the reduced disturbance and 

avoidance when motorized use on native surfaced routes that are seasonally restricted. Finally cross 

country travel would be prohibited on 17,178 acres of sooty grouse habitat with the implementation of the 

action alternatives where disturbance, avoidance, and abandonment by sooty grouse would be reduced or 

eliminated. Alternative 1 would have the greatest cumulative impact to sooty grouse habitats, where cross 

country travel would continue and increase, affecting 17,178 acres of late-seral open canopy coniferous 

forest habitat. 

Summary of Sooty Grouse Status and Trend at the Bioregional Scale. The Tahoe NF LRMP (as 

amended by the SNF MIS Amendment) requires bioregional-scale habitat and distribution population 

monitoring for the sooty grouse; hence, the late-seral open canopy coniferous forest effects analysis for 

the Tahoe NF Motorized Travel Management Project must be informed by both habitat and distribution 

population monitoring data. The sections below summarize the habitat and distribution population status 

and trend data for the sooty grouse. This information is drawn from the detailed information on habitat 

and population trends in the SNF Bioregional MIS Report (USDA Forest Service 2008), which is hereby 

incorporated by reference.

Habitat Status and Trend. There are currently 75,000 acres of late-seral open canopy coniferous 

forest (ponderosa pine, Sierran mixed conifer, white fir, red fir, and eastside pine) habitat on NFS lands in 

the Sierra Nevada. The trend is slightly decreasing (from 3% to 1% within the last decade on NFS lands). 

Population Status and Trend. The sooty grouse has been monitored in the Sierra Nevada at various 

sample locations by hunter survey, modeling, point counts, and breeding bird survey protocols, including 

California Department of Fish and Game Blue (Sooty) Grouse Surveys (Bland 1993, 1997, 2002, 2006); 

California Department of Fish and Game hunter survey, modeling, and hunting regulations assessment 

(CDFG 2004a, CDFG 2004b); Multi-species inventory and monitoring on the Lake Tahoe Basin 

Management Unit (LTBMU 2007); and 1968 to present – BBS routes throughout the Sierra Nevada 

(Sauer et al. 2007). These data indicate that sooty grouse continue to be present across the Sierra Nevada, 

except in the area south of the Kern Gap, and current data at the range wide, California, and Sierra 

Nevada scales indicate that the distribution of sooty grouse populations in the Sierra Nevada north of the 

Kern Gap is stable. 

Relationship of Project-Level Habitat Impacts to Bioregional-Scale Sooty Grouse Trend. Under 

Alternative 1, 4,247 acres (6% of Sierra Nevada habitat) of late-seral open canopy coniferous forest 

would be directly or indirectly affected, which could substantially disturb, displace, or cause avoidance to 

sooty grouse from cross country motorized travel, including on existing unauthorized motorized routes.

Alternative 1 could result in a downward habitat trend for the sooty grouse.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 259

The action alternatives all result in a low risk to blue grouse security habitat, where between 0 acres 

and 708 acres (0 to 1% of Sierra Nevada-wide habitat) are influenced by proposed motorized route 

additions and/or reopened ML 1 roads. The Tahoe NF Motorized Travel Management Project action 

alternatives would not alter the existing trend in the habitat, nor would it lead to a change in the 

distribution of sooty grouse across the Sierra Nevada bioregion.

Old Forest Conifer Associated Species: Affected Environment

The old forest conifer associated species group is comprised of the California spotted owl (Strix 

occidentalis occidentalis), northern goshawk (Accipiter gentilis), great gray owl (Strix nebulosa), 

American marten (Martes americana), Pacific fisher (Martes pennanti), and coniferous forest birds brown 

creeper (Certhia americana). These species are associated with old forests (moderate to closed canopy) 

that can be impacted by activities associated with motorized trails and roads. Gaines et al. (2003)

conducted a literature review where a number of old forest associated wildlife species were identified as 

being negatively impacted by a variety of road and trail-associated factors. These impacts include habitat 

loss and fragmentation, road avoidance or displacement, harassment, and others. Growing concern over 

habitat fragmentation for old forest associated species has been expressed by individuals, environmental 

groups, and agency biologists. In addition, studies have shown that species within this group are sensitive 

to disturbance.

According to the Sierra Nevada Forest Plan Amendment (2004), which amends the Tahoe NF Land 

and Resource Management Plan (1990), habitat types that are important for old coniferous forest 

associated species (spotted owl, goshawk, marten, and fisher.) are California Wildlife Habitat 

Relationship (CWHR) 4M, 4D, 5M, 5D, and 6 vegetation types (stands of trees >11” dbh with >40% 

canopy cover). In addition, the Sierra Nevada Forest Plan Amendment provides broad management 

direction for Old Forest Emphasis Areas (OFEAS) where they are “managed to maintain or develop old 

forest habitat in areas containing the best remaining large blocks or landscape concentrations of old forest 

and areas that provide old forest functions (such as connectivity of habitat over a range of elevations to 

allow migration of wide-ranging old-forest-associated species).” Finally, the Tahoe NF developed a 

Carnivore Network based on suitable and potential suitable habitat for marten and fisher that provides 

another way of evaluating impacts to late-seral coniferous forest species and their habitats. 

Summary of trail and road associated impacts to late-seral coniferous forest species (Gaines, et al. 

2003):

• Mortality or injury resulting from a motorized vehicle running over or colliding with an animal;

• Loss and resulting fragmentation of habitat due to the establishment of roads, trails, or networks,

and associated human activities;

• Changes to habitat microclimate associated with the edge induced by roads or trails;

• Reduction in density of snags and down logs due to their removal near roads as facilitated by road 

and motorized trail access;
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

260 – Tahoe National Forest

• Collection of live animals for use as pets (such as amphibians and reptiles) as facilitated by the 

physical characteristics of roads or trails or by road or motorized trail access;

• A physical human-induced change in the environment that provides access for competitors or 

predators that would not have existed otherwise;

• Displacement of individual animals from a specific location that is being used for reproduction 

and rearing of young;

• Increase in heart rate or stress hormones when near a road or trail or network of roads or trails.

Old Forest Conifer Associated Species: Environmental Consequences

Effects Common to All Old Forest Conifer Associated Species 

Changes to the NFTS

Changes in Class of Vehicles: Although responses to motorized vehicle use varies by species and 

depends upon the type of vehicle, in addition to the intensity, timing, speeds, and amount motorized 

vehicle use, the specific species responses are not well understood. For this analysis, it is assumed that all 

vehicle types result in the same disturbance to all late-seral coniferous forest species. Therefore, changes 

in the class of vehicles would not vary in their effects to late-seral coniferous forest associated species for 

all of the proposed alternatives.

Wet weather seasonal restrictions: Alternatives 4, 5, and 6 would impose wet weather seasonal 

restrictions on all native surfaced roads and motorized trails within old coniferous forest species habitats 

where old forest species would benefit through the reduction of noise and disturbance associated with 

motorized use. Alternatives 1, 2, 3, and 7 do not impose wet weather restrictions on native surfaced 

motorized routes and therefore, late-seral closed canopied coniferous forest associated species would not 

benefit from wet weather seasonal restrictions.

Establishment of “Open Areas”: Establishment of “Open Areas” is discussed under “Summary of 

Effects Common to All Species.”

Amendments to the Forest Plan: the effects to old forest-conifer species are analyzed by their 

potential to be affected by the Forest Plan amendments of removing seasonal restrictions for deer as 

addressed in the Deer Environmental Consequences Section.

Introduction to Indicators used to Measure Effects for

Old Forest Conifer Associated Species

Three primary metrics will be used to evaluate the effects of the alternatives to old forest conifer 

associated species as follows:

Cross Country Travel: The acres of cross country travel within old forest conifer habitats (CWHR 

4M, 4D, 5M, 5 D, 6) are determined for each of the alternatives.

Additions to the NFTS: The Zone of Influence and Disturbance at a Specific Site are analyzed for 

motorized route additions to the NFTS by each alternative, as described below.

Zone of Influence: For motorized additions to the NFTS, the Zone of Influence within old forest

CWHR habitats are analyzed for each alternative to measure habitat fragmentation and other zonal effects 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 261

associated with motorized roads and trails including noise disturbance, avoidance, edge effects, mortality, 

etc. The distance from routes used to calculate the Zone of Influence for selected species in the old forest 

group was determined from a thorough review of available literature. For all species in this group, a Zone 

of Influence of 60 meters (length of one tree height of snags) along routes is used to determine the effects 

of habitat fragmentation from removal of snag and logs along routes for public safety. Delaney et al. 

(1999) found that late-seral coniferous forest associated species, such as the spotted owl, have shown to 

be sensitive to noise disturbance generated by helicopters within a distance of 100 meters, therefore a 

100-meter Zone of Influence was used to represent habitat effectiveness for late-seral forest associated 

species. A Zone of Influence within 200 meters of OFEAs encompasses a greater array of potential route 

associated effects to late-seral forest associated species including edge effects, habitat fragmentation, and 

habitat effectiveness.

Disturbance at a specific site: Disturbance at a specific site was analyzed for California spotted owl 

and northern goshawk by the determining the number of motorized route miles added within Protected 

Activity Centers. Also, miles of routes added within 1⁄4 mile of a reproductive site (nest site or nest grove) 

were evaluated by alternative under the species discussions for California spotted owl and northern 

goshawk, since disturbances within 1⁄4 mile of a reproductive site have the potential to disrupt or cause

reproductive failure to these species. 

Changes to the NFTS: The Zone of Influence of reopened Maintenance Level 1 roads and 

Disturbance to a specific site within old forest CWHR habitats were determined in similar way as 

motorized route additions were analyzed, as described above. The changes in class of vehicle and changes 

in seasonal restrictions are analyzed under “Effects Common to All Old Forest Conifer Species” above.

Introduction to Cumulative Effects for Old Forest Conifer Associated Species

Indicators used to Measure Cumulative Effects of Motorized Routes

Cross Country Travel: The cumulative effects of motorized cross country travel are described for both

current LMP motorized restrictions as well as proposed motorized restrictions for the alternatives. 

Motorized Route Density: Motorized route density is used as an indicator to measure cumulative 

effects of all the motorized routes at the Forest-wide scale. The Forest-wide scale gives an approximate 

coarse measure of habitat effectiveness for old forest associated species represented in this group. 

Motorized route density is presented at two scales, within mature and late-seral coniferous forest habitats 

(CWHR vegetation types 4M, 4D, 5M, 5D, and 6) and Old Forest Emphasis Areas (OFEAs). The type of 

impacts to old forest associated species depends on the type of motorized route, amount and type of use, 

and season of use. Although motorized route density thresholds for late-seral coniferous forest associated 

species are not well understood, route densities are presented to compare relative effects between the 

alternatives.

Zone of Influence of Motorized and Non-motorized Routes: The analysis of cumulative effects for 

old forest species focuses on the cumulative effects associated with roads and trails, including motorized 

and non-motorized use, and includes roads and trails on both NFS lands and non-NFS lands (private). 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

262 – Tahoe National Forest

For this analysis, cumulative effects are simply the sum total of direct and indirect effects of the 

alternatives plus the past, and reasonably foreseeable future impacts of routes. Adverse cumulative 

impacts includes proposed motorized route additions, reopened ML 1 routes, existing motorized routes on 

both NFS lands and non-NFS lands (private), and non-motorized routes. Non-motorized routes are 

considered to have some impact on old forest species, though they may or may not have similar impacts 

as motorized routes depending upon the intensity and level of use. Although, all motorized routes are not 

equal, and routes that are Interstate highways have a higher severity of effect than unpaved motorized 

routes, this analysis assumes all motorized routes have the same negative impact on old forest species. In 

all cases, existing routes are nearly constant for all the alternatives and would not vary between the 

alternatives in a significant way. Routes that are either classified as closed or decommissioned are 

considered positive cumulative effects since disturbance and habitat fragmentation would no longer occur 

because routes would become overgrown with vegetation over time and noise disturbance from motorized 

use would not occur. Reasonably foreseeable impacts of motorized routes are considered by assessing the 

potential for motorized route proliferation for each alternative.

Other cumulative effects to old forest conifer associated species include effects of vegetation 

management, fuels reduction, catastrophic wildfires, recreation, grazing and others. These cumulative 

effects are complex and difficult to quantify over space and time, and are qualitatively described. 

Cumulative Effects Boundary in Space and Time

The boundary of the Tahoe NF (including NFS lands and non-NFS lands) is the geographic boundary 

used for analyzing cumulative effects of motorized vehicle routes on old forest associated species. This 

area is sufficiently large enough to include home ranges for the species occurring within this group and 

includes an array of forest vegetation types important to old forest species from low elevations to high 

elevations including mixed conifer types, true fir types, yellow pine types, lodgepole pine, and subalpine 

conifer types. The temporal scale used for analyzing is all past and present routes which comprise the 

current motorized route situation and future routes that may develop within the next 20 years out into the 

future. This timeframe sufficiently analyzes any foreseeable future routes on the Tahoe NF.

Old Forest Conifer Habitat (CWHR types 4M, 4D, 5M, 5D, and 6)

Indicators used to Measure Effects

Additions to the NFTS (Zone of Influence): For each of the proposed alternatives, the Zone of 

Influence within old forest habitat (CWHR 4M, 4D, 5M, 5D, 6) was determined at three scales - within 60 

meters, 100 meters, and 200 meters of motorized route additions. The three different scales were used to 

represent the array of route-associated factors for various species represented in the group. In general, a 

60 meter Zone of Influence represents habitat fragmentation to old forest species as it relates to habitat 

components, such as snag and down log removal along routes for public fuelwood and public safety 

hazards. Sixty meters represents the maximum height of a tree potentially removed as a hazard tree. 

Delaney et al. (1999) found that old forest species, such as the spotted owl, have shown to be sensitive to 

noise disturbance generated by helicopters within a distance of 100 meters, therefore a 100-meter Zone of 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 263

Influence was used to represent habitat effectiveness for old forest species. Gaines et al. (2003) reported 

that brown creepers and other forest interior bird species avoided an area within 200 meters of motorized 

routes. Potential impacts within a 200-meter Zone of Influence to old forest conifer associated species 

includes potential negative impacts including avoidance due to noise disturbance or edge effects, habitat 

fragmentation, introduction of invasive species (i.e. brown-headed cowbirds), microclimate changes, and 

others. 

The Zone of Influence may vary by species and by species responses to route type, level of use and 

intensity. Since absolute thresholds of concern thresholds for any given species are difficult to determine 

due to limited research on effects of routes, various zones of influence were selected that would represent 

the array of responses that route associated factors might influence fitness or distribution of species in the 

group. Species-specific discussion in relation to the various zones of influence will be discussed in detail.

The analysis for these three Zones of Influence was calculated for the DEIS and the results showed 

maximum percentage differences among all alternatives of 2-3%. Further, the largest ZOI, 200 m, 

incorporates all of the impacts intended to be measured by the results of the other two distances. 

Therefore, in this analysis, only 200 m ZOI was used.

Changes to the NFTS (Reopened ML 1 Roads - Zone of Influence): The 200 meter Zone of 

Influence was determined for all reopened ML 1 roads as it was completed for motorized route additions.

Direct and Indirect Effects

Cross Country Travel: Cross country motorized travel would continue on at 268,895 acres of old forest 

habitat under Alternative 1, and would be prohibited under all the action alternatives. Habitat 

fragmentation, disturbance, and avoidance associated with cross country travel would benefit old forest 

species since prohibition of cross country travel on nearly 300,000 acres would be significantly reduced 

under the action alternatives.

Additions to the NFTS (Zone of Influence): Comparing the Zone of Influence at 200 meters of 

motorized routes to be added to the NFTS within old forest habitat as classified by CWHR types 4M, 4D, 

5M, 5D, and 6, provides a relative indication of how the alternatives affect habitat effectiveness for many 

old forest associated species, such as forest carnivores (i.e. marten and fisher) and forest coniferous 

songbird species (i.e. brown creeper). As indicated above, a study by Gaines et al. 2003 indicated that 

brown creepers and other forest interior bird species avoided an area within 200 meters of motorized 

routes. Potential impacts within a 200-meter Zone of Influence to late-seral coniferous forest associated 

species includes potential negative impacts including avoidance due to noise disturbance or edge effects, 

habitat fragmentation, introduction of invasive species (i.e. brown-headed cowbirds), microclimate 

changes, and others.

Alternative 1 contributes considerably to the reduction in habitat effectiveness for old forest species 

where 18% of old forest habitat would be negatively influenced by cross country motorized travel, 

including use of existing unauthorized motorized routes. Alternatives 2, 5, and 6 contribute to a 1% 

reduction in habitat effectiveness for old forest associated species, followed by Alternatives 4 and 7 where
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

264 – Tahoe National Forest

less than 1% reduction in habitat effectiveness would occur. Alternative 3 would not contribute to a 

reduction in habitat effectiveness.

Changes to NFTS (Reopened ML 1 Roads-Zone of Influence): Only Alternative 5 would impact 

old forest habitat, where 1% old forest CWHR habitat would be influenced by motorized activities 

associated with the reopening of ML 1 roads. Although Alternatives 4, 6, and 7 would open ML 1 roads, 

there would be less than 1% impact. None of the remaining alternative proposes to reopen ML 1 roads, 

and would therefore, not affect old forest habitat. Refer to Table 3.03-48.

Table 3.03-48. Proportion of Old Forest Habitat (CWHR 4M, 4D, 5M, 5D, and 6) within 200 Meters of Motorized 

Route Additions and Reopened ML 1 Roads

Alt 11 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7 

Percent of old forest CWHR habitat in ZOI of 

Motorized Additions

18% 1% 0% <1% 1% 1% <1%

Percent of old forest CWHR habitat in ZOI of 

Reopened ML 1 Roads

0% 0% 0% 0% 1% 0% 0%

1

Alternative 1 includes unauthorized routes associated with continued cross country travel

Summary of Direct and Indirect Effects 

Table 3.03-49 summarizes the overall net effect to old forest CWHR habitat from the proposed actions 

from motorized route additions to the NFTS, prohibition of cross country travel, and changes to NFTS.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 265

Table 3.03-49. Old Forest CWHR Habitat- Summary of Overall Net Direct and Indirect Effects

Indicator Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres of Habitat Where Cross 

Country Travel is Prohibited

0 267,952 267,952 267,952 267,952 267,952 267,952

Motorized Route Additions to NFTS*

Trend of Effect Negative (most 

impactive 

alternative)

Negative 

(shares 

2ndmost 

impactive 

alternative with 

Alts 5 & 6)

No Effect Negative (shares 

3rd most 

impactive 

alternative with 

7)

Negative 

(shares 2nd most 

impactive with 

alternatives 2 & 

6)

Negative 

(shares 2nd most 

impactive with 

alternatives 2 & 

5)

Negative 

(shares 3re

most impactive 

alternative with 

alternative4)

Percent Habitat Affected in ZOI 18% 1% 0% <1% 1% 1% <1%

Establishment of Motorized “Open 

Areas”

No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Changes to 

the NFTS

Change in Season 

of Use (wet weather 

restrictions)

No Effect No Effect No Effect Beneficial from 

reduced 

disturbance

Beneficial 

from reduced 

disturbance

Beneficial 

from reduced 

disturbance

No Effect

Change in Class of 

Vehicles

No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Reopened Maintenance Level 1 (ML 1) Roads

Trend of Effect No Effect No Effect No Effect No Effect Negative No Effect No Effect

Percent Habitat 

Affected in ZOI

0% 0% 0% 0% 1% 0% 0%

Amendments to the Forest Plan No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Overall Net Effect of Proposed 

Actions 

Negative effects 

from unauthorized 

cross country 

travel; Increases 

habitat 

fragmentation.

Beneficial 

effect from 

prohibited 

cross country 

travel, reduces 

habitat 

fragmentation

Beneficial effect 

from prohibited 

cross country 

travel, reduces 

habitat 

fragmentation.

Beneficial effect 

from prohibited 

cross country 

travel; reduces 

habitat 

fragmentation.

Beneficial effect 

from prohibited 

cross; reduces 

habitat 

fragmentation.

Beneficial effect 

from prohibited 

cross country 

travel; reduces 

habitat 

fragmentation.

Beneficial effect 

from prohibited 

cross country 

travel; reduces 

habitat 

fragmentation.

* Alternative 1 includes existing unauthorized routes that would continue with cross country travel, while all the action alternatives include proposed route additions.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

266 – Tahoe National Forest

Cumulative Effects

Cumulative Effects of All Motorized Routes

Motorized Route Density in Old Forest Coniferous Habitat (CWHR types 4M, 4D, 5M, 5D, and 6)

The average route density of all motorized routes within old forest CWHR habitat types was determined 

within 7th field watersheds for each alternative (Table 3.03-50). In general, lower motorized route 

densities correlate with higher habitat connectivity or conversely, higher motorized route densities equate 

to greater habitat fragmentation within old forest habitat.

Alternative 1 would contribute to the greatest cumulative effects within old forest CWHR habitat due 

to the continuance of unmanaged cross country travel, where the lowest proportion of old forest CWHR 

habitat (14%) is within route densities of less than 2 miles/square mile as compared to the action 

alternatives (22-25%). Alternatively, Alternative 1 has the greatest amount of old forest CWHR habitat 

(34%) that have relatively high motorized route densities of 4-6 mi/mi2

, where the least amount of habitat 

connectivity for old forest associated species is provided compared to all the action alternatives (10-11% 

habitat with route densities of 4-6 mi/mi

2

).

For all the action alternatives, the cumulative motorized route density would be similar since cross 

country travel would be prohibited, including the majority of existing unauthorized routes. Alternative 5 

would have slightly greater cumulative effects compared to alternatives the remaining action alternatives.

High motorized route densities, such as would occur under Alternative 1, could be a limiting factor in the 

distribution and abundance for some old forest conifer associated species. Therefore, Alternative 1 poses 

the greatest risk to old forest conifer species’ abundance and distribution, especially for species that 

require large patches of undisturbed habitat.

Table 3.03-50. Proportion of Late-seral Coniferous Forest Habitat (CWHR types 4M, 4D, 5M, 5D, and 6) with 

motorized route densities between 0 and 6 miles/square mile (Average motorized route densities within 7th

Field Watersheds)

Motorized Route Density

(miles/square mile)

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

0 Miles/Square mile <1% <1% <1% <1% <1% <1% <1%

0-2 Miles/Square mile 14% 25% 25% 25% 22% 25% 25%

2-4 Miles/Square mile 47% 63% 63% 63% 65% 64% 63%

4-6 Miles/Square mile 34% 10% 10% 10% 11% 10% 10%

>6 Miles/Square mile 4% 2% 1% 2% 2% 2% 2%

Zone of Influence at 200 meters. The cumulative effects to mature/forest forests (CWHR types 4M, 

4D, 5M, 5D, 6 within a 200 meter Zone of Influence are compared for the proposed alternatives (Tables 

3.03-49). When comparing the relative cumulative effects to late-seral forests within a 200 meter Zone of 

Influence by adding up all the direct and indirect effects of proposed alternatives plus the cumulative 

effects of past, present, and future actions, Alternative 1 would have the greatest overall cumulative 

impact (cumulative impact score = 60%) and poses the greatest risk to habitat connectivity, as well as 

other negative cumulative impacts associated with motorized activities within old forest habitat as a result 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 267

of approximately 18% of old forest habitat that would be directly and indirectly affected by continued 

cross country motorized travel on 267,952 acres, including continued use of existing unauthorized routes

(Table 3.03-51). In addition, Alternative 1 would likely result in uncontrolled proliferation of 

unauthorized routes since unmanaged cross country travel would likely continue and grow into the future.

All the action alternatives are similar in their overall cumulative impact within a 200 meter Zone of 

Influence that affects between 42 to 44 percent of old forest CWHR habitat. No direct, indirect, or 

cumulative impacts would occur from implementing Alternatives 3, since no motorized routes would be 

added to the NFTS or added within old forest CWHR habitat.

Table 3.03-51. Cumulative Effects for Percent of Old Forest Conifer Habitat (CWHR 4M, 4D, 5M, 5D, 6) within 

200 meters of All Routes

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Direct and Indirect Effects of proposed alternatives

Motorized route additions to the NFTS1

(negative impact)

18% 1% 0% <1% 1% 1% <1%

Reopened ML 1 Roads (negative) 0% 0% 0% 0% 1% 0% 0%

Unauthorized Routes where cross country 

travel would be prohibited (postive)

0% 17% 18% 17% 16 17% 17%

Cumulative effects of past, present, and proposed actions

Existing motorized routes- NFS lands 

(negative impact)

26% 26% 26% 26% 26% 26% 26%

Existing motorized routes on private land -

non-NFS lands (negative impact)

12% 12% 12% 12% 12% 12% 12%

Existing non-motorized routes (negative 

impact)2 4% 4% 4% 4% 4% 4% 4%

Decommissioned routes – (positive impact) 1% 1% 1% 1% 1% 1% 1%

Existing Closed ML 1 Roads (positive impact) 1% 1% 1% 1% 1% 1% 1%

Total Cumulative Effects

Overall Cumulative Effects equals the total 

of all impacts, both positive and negative

60% 43% 42% 42% 44% 43% 42%

1

Motorized Route additions- Alternative 1 includes unauthorized routes with continued cross country travel, while all the action 

alternatives includes motorized route additions to the NFTS.

2

Non-motorized-assumption: non-motorized impact is limited to 60 meters from trail and that no impact occurs beyond 60 meters

Overall Cumulative Effects from Past, Present

and Reasonably Foreseeable Future

Appendix H (Reasonably Foreseeable Projects and Cumulative Effects) provides a list and description of 

past, present, and reasonably foreseeable projects on NFS lands and private lands within the Tahoe NF 

boundary. Some, but not all, of these activities would contribute to impacts to late-seral coniferous forest 

associated species within the cumulative effects boundary. See overall cumulative effects for spotted owl 

for a summary of cumulative effects from past, present, and reasonably foreseeable projects for all 

species.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

268 – Tahoe National Forest

Old Forest Emphasis Areas (OFEAs)

Indicators used to Measure Direct and Indirect Effects

Motorized Route Density: Motorized route density analysis is conducted at a Forest-wide scale to give 

an approximate coarse measure of habitat effectiveness for old forest conifer associated species 

represented in Old Forest Emphasis Areas (OFEAs). The type of impacts to old forest associated species 

depends on the type of motorized route, amount and type of use, and season of use.

Zone of Influence: The Zone of Influence is analyzed for each alternative to measure habitat 

fragmentation and other zonal effects associated with motorized routes and trails including noise 

disturbance, avoidance, edge effects, mortality, etc. The distance from motorized routes used to calculate 

the Zone of Influence for OFEAs was determined from a thorough review of available literature. A Zone 

of Influence of 60 meters (length of one tree height of snags) along motorized routes is used to determine 

the effects of habitat fragmentation from removal of snag and logs along motorized routes for public 

safety. Zone of Influence within 200 meters of OFEAs provides encompasses a greater array of potential 

route associated effects to old forest species including edge effects, habitat fragmentation, and habitat 

effectiveness. The results of the 60-meter ZOI calculation are available in the project record; however,

because the results of the 200-meter ZOI display all the impacts also displayed by the 60 m ZOI, this 

analysis refers only to the 200-meter analysis.

Direct and Indirect Effects

Cross Country Travel. The ban of motorized cross country travel on 394, 847 acres within OFEAs 

would benefit old forest associated species and reduce disturbance and habitat fragmentation. Under 

Alternative 1 cross country motorized travel would continue where disturbance to old forest associated 

species and habitat fragmentation on 394,847 acres within OFEAs would continue. 

Additions to the NFTS (Zone of Influence at 200 meters in OFEAs). The zones of influence 

within OFEAs are analyzed for the proposed alternatives within 200 meters of proposed additions of 

motorized routes to the NFTS (Table 3.03-52). Comparing the Zone of Influence at 200 meters of 

proposed unauthorized routes provides a relative indication of how the alternatives affect habitat 

effectiveness for late-seral coniferous forest associated species within OFEAs. Potential negative impacts 

within a 200-meter Zone of Influence to late-seral coniferous associated species includes avoidance due to 

noise disturbance or edge effects, habitat fragmentation, introduction of invasive species (i.e. brownheaded cowbirds), microclimate changes, and others. Alternative 1 contributes considerably to reduced 

habitat effectiveness for old forest species where 22% of OFEAs would be negatively influenced by 

continued cross country travel and the associated continued use of existing unauthorized routes. 

Alternative 5 contributes to 2% reduction in habitat effectiveness for old forest associated species, 

followed by Alternatives 2 and 6 at 1% reduction in habitat effectiveness. Alternative 7 contributes to less 

than 1% reduction in habitat effectiveness for old forest associated species. Alternatives 3 and 4 would 

not affect overall habitat effectiveness for old forest species within OFEAs.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 269

Summary of Direct and Indirect Effects 

Table 3.03-52 summarizes the overall net effect to Old Forest Emphasis Areas (OFEAs) from the 

proposed actions from motorized route additions to the NFTS, prohibition of cross country travel, wet 

weather restrictions, and seasonal closures.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

270 – Tahoe National Forest

Table 3.03-52. Old Forest Emphasis Areas (OFEAs) - Summary of Overall Net Direct and Indirect Effects 

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres prohibited 0 394,847 394,847 394,847 394,847 394,847 394,847

ZOI percent OFEAs prohibited 0% 17% 18% 17% 16% 17% 17%

Establishment of “Open Areas” No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Motorized Route Additions to NFTS

Trend of Effect Negative Slight Negative No Effect Slight Negative Slight Negative Slight Negative Slight Negative

ZOI Percent OFEAs Affected 18% 1% 0% <1% 1% 1% <1%

Changes to 

the NFTS

Wet Weather 

Restrictions

No Effect No Effect No Effect Beneficial from 

reduced 

disturbance

Beneficial from 

reduced 

disturbance

Beneficial from 

reduced 

disturbance

No Effect

Change in Class of 

Vehicles

No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Reopened ML 1 Roads 0% 0% 0% 0% 1% 0% 0%

Amendments to Forest Plan No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Overall Net Effect of Proposed 

Actions

Negative, 

continued 

cross country 

travel on 

394,847 

acres.

Increases 

fragmentation

within OFEAs.

3rd most 

beneficial 

alternative, 

shared with Alt 

6. 

Reduces 

fragmentation

from cross 

country travel 

prohibitions.

Most beneficial 

alternative-- no 

motorized route 

additions.

Reduces 

fragmentationfrom 

cross country 

travel prohibitions.

2nd most 

beneficial 

alternative 

shared with Alt 

7. 

Reduces 

fragmentation

from cross 

country travel 

prohibitions.

Least beneficial 

alternative-- 2% 

ZOI affected 

from route 

additions and 

reopened ML 1 

roads.

Reduces 

fragmentation 

from cross 

country travel 

prohibitions.

3rd most 

beneficial 

alernative, 

shared with Alt 

2.

Reduces 

fragmentation 

from cross 

country travel 

prohibitions.

2nd most 

beneficial 

alternative 

shared with Alt 

4. 

Reduces 

fragmentation. 

from cross 

country travel 

prohibitions.

* Alternative 1 includes existing unauthorized routes that would continue with cross country travel, while all the action alternatives include proposed route additions.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 271

Cumulative Effects Old Forest Emphasis Areas (OFEAs)

Cumulative Motorized Route Density in OFEAs

The average motorized route densities (all motorized routes including existing routes, added routes, and 

reopened ML 1 roads) within the Old Forest Emphasis Areas (OFEAs) land allocation were determined 

within 7th field watersheds for each alternative (Table 3.03-53). In general, lower motorized route 

densities correlate with higher habitat connectivity or conversely, higher motorized route densities equate 

to greater habitat fragmentation of OFEAs. 

Alternative 1 provides the least amount of habitat connectivity within OFEAs, where approximately 

35% of OFEAs have route densities in the highest route density categories (4-6 mi/mi2

), and the lowest 

amount of OFEAs in the lowest route density categories (0-2 mi/mi2

).

When comparing the action alternatives, Alternative 5 would result in next greatest proportion of 

OFEAs (9%) within the 4-6 mi/mi2 route density category, followed by the remaining action alternatives 

which have slightly lower route densities within OFEAs. The remaining action alternatives would result 

in approximately 5-6% of the OFEAs within the 4-6 mi/mi2 route density category. Therefore, the 

cumulative route density of motorized routes for action alternatives would similarly result in the least 

amount of habitat fragmentation within OFEAs as compared to Alternative 1, followed by Alternative.

Table 3.03-53. Proportion of Old Forest Emphasis Areas with motorized route densities between 0 miles per 

square mile and greater than 6 miles per square mile (average motorized route densities within 7th field 

watersheds)

Route Density (miles/mi2) Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

0 Miles/Square Mile <1% <1% <1% <1% <1% <1% <1%

0-2 Miles/Square Mile 11% 23% 24% 24% 19% 22% 23%

2-4 Miles/Square Mile 53% 71% 71% 71% 72% 72% 71%

4-6 Miles/Square Mile 35% 5% 6% 5% 9% 5% 5%

>6 Miles/Square Mile 1% 1% 0% 1% 1% 1% 1%

Cumulative Effects from All Motorized Routes

200-Meter Zone of Influence. The cumulative effects to OFEAs within a 200-meter Zone of Influence

are compared for the proposed alternatives (Table 3.03-54). When comparing the relative cumulative 

effects to OFEAs within a 200-meter Zone of Influence by summing the direct and indirect effects of 

proposed alternatives and the cumulative effects of past, present, and future actions, Alternative 1 has the 

greatest overall cumulative impact (cumulative impact score = 55%) that poses the greatest risk to habitat 

connectivity and other negative cumulative impacts associated with motorized routes within OFEAs due 

to approximately 17% of OFEAs that are influenced by motorized cross country travel, including 

continued use of existing unauthorized routes. In addition, Alternative 1 would contribute significantly to 

the continued proliferation of unauthorized routes because unmanaged cross country motorized travel 

would continue into the future and would have a high likelihood of increasing. 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

272 – Tahoe National Forest

The action alternatives would directly and indirectly affect either none or only a very small amount of 

Tahoe NF OFEAs (0-2%) from the addition of motorized route additions and reopened ML 1 roads. Only 

Alternative 5 proposes to reopen ML 1 roads. Therefore, habitat fragmentation within OFEAs for the 

action alternatives would be reduced compared to Alternative 1. Cumulative effects would be slightly 

increased for Alternatives 2, 5, 6, and 7. Alternatives 3 and 4 would not contribute to cumulative impacts 

since motorized route additions nor would reopening of ML roads be proposed. Overall cumulative 

impacts for the action alternatives would be beneficial compared to Alternative 1, where 15-17% of 

OFEAs would have reduced habitat fragmentation from the prohibition of motorized cross country travel, 

including on existing unauthorized routes.

Table 3.03-54. Cumulative Effects to Old Forest Emphasis Areas within a 200-meter Zone of Influence of All 

Routes 

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Direct and Indirect Effects of proposed alternatives

Proposed Motorized route additions to NFTS 

(negative impact)1 17% 1% 0% 0% 1% 1% <1%

Reopened ML 1 Roads (negative) 0% 0% 0% 0% 1% 0% 0%

Unauthorized Routes where cross country travel 

would be prohibited (positive)

0% 16% 17% 17% 16% 16% 17%

Cumulative Effects of past, present, and proposed actions

Existing motorized routes - NFS lands (negative 

impact)

24% 24% 24% 24% 24% 24% 24%

Existing routes on non-NFS lands (private) (negative 

impact)

10% 10% 10% 10% 10% 10% 10%

Existing non-motorized routes (negative impact)2 4% 4% 4% 4% 4% 4% 4%

Decommissioned routes (positive impact) 1% 1% 1% 1% 1% 1% 1%

Total Cumulative Effects

Overall Cumulative Effects equals the total of all 

impacts, both positive and negative

55% 39% 38% 38% 40% 39% 38%

1

Motorized Route additions- Alternative 1 includes unauthorized routes with continued cross country travel, while all the action 

alternatives includes motorized route additions to the NFTS.

2

Non-motorized-assumption: non-motorized impact is limited to 60 meters from trail and that no impact occurs beyond 60 meters

Overall Cumulative Effects from Past, Present

and Reasonably Foreseeable Future

Appendix H (Reasonably Foreseeable Projects and Cumulative Effects) provides a list and description of 

past, present, and reasonably foreseeable projects on NFS lands and private lands within the Tahoe NF 

boundary. Some, but not all, of these activities would contribute to impacts to late-seral coniferous forest 

associated species within the cumulative effects boundary. See overall cumulative effects for spotted owl 

for a summary of cumulative effects from past, present, and reasonably foreseeable projects for all lateseral coniferous forest species.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 273

Compliance with the Forest Plan and Other Direction

The Record of Decision (ROD) for the 2004 Sierra Nevada Forest Plan Amendment identified the 

following standards and guidelines applicable to habitat connectivity for old forest associated species,

including the California spotted owl, Northern goshawk, American marten, and Pacific fisher.

1. Minimize old forest habitat fragmentation. Assess potential impacts of fragmentation on old 

forest-associated species (particularly fisher and marten) in biological evaluations (standard and 

guideline 27).

All of the action alternatives reduce fragmentation of old forest habitat. The Biological 

Evaluation for old forest (late-seral) - associated species, including the California spotted owl, 

Northern goshawk, American marten, and the Pacific fisher determined that the action 

alternatives for the Tahoe NF Travel Management Project may affect individual species, but 

would not lead to a downward trend toward federal listing.

2. Assess the potential impact of projects on the connectivity of habitat for old forest associated 

species standard and guideline 28).

The analysis conducted as described in the above sections, indicated that the action alternatives all 

reduce habitat fragmentation for old forest (late-seral) – associated species, by prohibiting motorized 

cross country travel on 394,847 acres within Old Forest Emphasis Areas, 267,952 acres within CWHR 

4M, 4D, 5M, 5D, and 6 habitat types, and 396,602 acres within the Tahoe NF Forest Carnivore Network; 

all which are important habitats for old forest (late-seral) associated species.

Alternative 1 complies the least with the LRMP direction for minimizing habitat fragmentation, by 

allowing the continuance of cross country travel within OFEAs, CWHR 4M, 4D, 5M, 5D, and 6 habitat 

types, and the Tahoe NF Forest Carnivore Network on over 250,000 acres. In addition, Alternative 1 

directly, indirectly, and cumulatively affects the greatest amount of habitat for old forest-associated 

species from the continuance of cross country travel, including on unauthorized routes. Alternative 3 

minimizes fragmentation of old forest habitat the most of all the action alternatives since no motorized 

route additions to the NFTS are proposed within old forest habitats, and therefore minimizes habitat 

fragmentation the most of all the action alternatives.

Spotted Owl: Affected Environment

The California spotted owl is designated by the Regional Forester as a Sensitive Species and is identified 

as a Management Indicator Species on the Tahoe NF. The Tahoe NF has 181 designated California spotted 

owl Protected Activity Centers. Protected Activity Centers (PACs) are delineated around spotted owl 

territorial pairs or territorial individuals. Within the polygons of PACs are point locations of known nests 

or roosts called Activity Centers. The Sierra Nevada Forest Plan Amendment (2004) provides direction to 

designate Protected Activity Centers and Home Range Core Areas (HRCAs) by using CWHR types 6, 

5D, 5M, 4D, and 4M. These CWHR types are in essence considered suitable habitat (nesting and 

foraging) for California spotted owls. Pure eastside pine types are not considered suitable for California 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

274 – Tahoe National Forest

spotted owls. Currently, there are 294,487 acres suitable spotted owl habitat with CWHR types 6, 5D, 5M, 

4D, and 4M on the Tahoe NF (excluding pure eastside pine type). 

The Tahoe NF has conducted surveys for spotted owl presence and reproductive status across the 

forest since the early 1980s. Approximately 85% of suitable habitat has been surveyed on the Tahoe 

National Forest following R-5 USDA Forest Service Protocol. Based on survey results to date, 181 

Protected Activity Centers (PACs) and Home Range Core Areas (HRCA) have been designated covering 

184,000 acres within the Tahoe NF administrative boundary. PACs and HRCAs are comprised of the best 

available habitat encompassing approximately 300 and 700 acres, respectively. 

Spotted Owl: Environmental Consequences

Introduction

Gaines et al. (2003) reviewed studies on the northern spotted owl and determined that road and trail 

associated factors that were likely to affect spotted owls were collisions, disturbance at a specific site, 

physiological response, edge effects, and snag reduction. These same factors are expected to affect the 

California spotted owl in a similar way based upon available literature (Verner et al. 1992, Seamans 2005, 

Blakesley 2003). Since the California spotted owl is the same species as the Northern spotted owl and 

have similar biological and ecological requirements, both subspecies of spotted owls are expected to 

behave and respond to disturbance similarly. 

Collisions: Collisions with vehicles are known to be a source of mortality for spotted owls. The 

degree to which this occurs on the Tahoe NF is unknown. However, at least one spotted owl was killed by 

a vehicle collision on a highway on the Eldorado NF.

Disturbance at a Specific Site: The Forest Service considers activities greater than 0.25 miles (~400 

meters) from a spotted owl nest site to have little potential to affect spotted owl nesting. In addition, 

Delaney et al. (1999) found that Mexican spotted owls were found to show an alert response to chainsaws 

at distances less than 0.25 miles. Preliminary study results on a Northern spotted owl study in northern 

California indicated that spotted owls did not flush from nest or roost sites when motorcycles were greater 

than 105 meters away during the post-fledgling period (Delaney and Grubb 2001). In addition, Delaney 

and Grubb (2003) found that spotted owl responses to motorcycle noise depended upon an array of 

complex factors, including sound level and frequency distribution, stimulus distance and event duration, 

motorcycle type and condition, frequency of motorcycle events, number of motorcycles per group, trail 

slope, topography, road substrate and condition, and microphone position relative to sound source. In 

general, motorcycle noise did not appear to affect reproductive success. However, this study is ongoing 

and impacts of motorcycle noise are not conclusive at this point.

Wasser et al. (1997) found that stress hormone levels were significantly higher in male northern 

spotted owls (but not females) when they were located less than 0.41 km from a major logging road 

compared to spotted owls in areas greater than 0.41 km from a major logging road. It is not well 

understood how elevated stress hormones affect spotted populations. However, Marra and Holberton 

(1998) reported that chronic high levels of stress hormones (corticosterone) may have negative effects on 

reproduction or physical condition of individual owls. Swarthout and Steidl (2001) found hikers caused 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 275

juvenile and adult spotted owls to flush at less than 12meters and less than 24 meters, respectively. 

Mexican spotted owls did not elicit any response from hikers that exceeded a distance of 55 meters.

Habitat Loss, Fragmentation and Edge Effects: California spotted owls may be affected by edge 

effects from roads when roads and motorized trails fragment suitable habitat. Several studies indicate the 

California spotted owl is sensitive to changes in forest canopy closure and habitat fragmentation 

(Seamans 2005, Blakesley 2003) that could result from a network of roads. Roads and motorized trails 

can result in a reduction in interior forest patch size which decreases the amount of habitat available and 

increases the distance between suitable interior forest patches for old forest conifer associated species 

such as the spotted owl. 

Snags and down logs are important habitat components for spotted owls, as well as many other 

species associated with old forest conditions. Forest system roads and motorized trails can contribute to 

the fragmentation of old forest habitat components through the reduction of snags and logs. Hazard trees 

are those trees that pose a risk of falling on a road or facility including recreational facilities such as 

campgrounds, trailheads, etc. Snags along roads used by the public that are considered to be hazard trees 

would be expected to be removed for public safety. In addition, the amount of logs and snags along 

roadsides are expected to be reduced from public fuelwood gathering

Spotted Owl Motorized Impact Factors for Analysis

The effects of the alternatives on spotted owls are analyzed for two road and trail associated factors:

• Effects to spotted owls from disturbance at a specific site (nesting habitat within PACs and nest 

locations).

• Effects to spotted owls from habitat fragmentation and edge effects within a Zone of Influence of 

motorized routes.

Assumptions for Determining Effects to Spotted Owl

Although the type and amount of use along the different types of routes may result in different effects to 

spotted owls, all motorized routes are treated equally in this analysis because the relationship between 

effects and motorized route type and intensity of use is complex and not well understood. For example, 

the type of motorized road or trail likely varies in how roads and motorized trails contribute to spotted 

owl disturbance and habitat fragmentation: high clearance roads generally receive less use than roads used 

by passenger vehicles, which would equate to less noise disturbance to owls, and single track motorcycle 

trails would likely fragment habitat less than would a passenger road due to the narrower width of the 

single track motorcycle routes that would result in removing less habitat. However, noise generated from 

motorcycles along trails may contribute to greater noise disturbance to spotted owls than would a 4x4 

jeep. Since impacts to spotted owls are not well understood, impacts from all motorized routes, regardless 

of motorized route type and intensity of use, are treated the same.
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276 – Tahoe National Forest

Spotted Owl: Disturbance at a Specific Site

Indicators used to Measure Effects

Cross Country Travel: The acres of cross country travel within spotted owl Protected Activity Centers 

(PACs) and within 0.25 mile radius of spotted owl nest sites or nest stands are determined for each of the 

alternatives.

Additions to the NFTS and Changes to the NFTS--Reopened ML 1 Roads: Motorized route 

additions to the NFTS and Changes to the NFTS from Reopened ML 1 Roads are analyzed to determine 

how they would impact spotted owl “disturbance to a specific site. Disturbance to spotted owl PACs and 

nest sites is analyzed for the alternatives at three scales - within 0.25 miles of spotted owl Activity Centers 

(nest sites or nest groves), within PACs and, and within HRCAs.

• Nest or Nest Stand (Within a 0.25 miles radius of spotted owl Activity Centers): Activity 

Centers represent known spotted owl nesting locations that may include most recently known nest 

site or nest stand. The miles of proposed motorized route additions and the miles of reopened ML 

1 roads within a 0.25 mile radius of spotted owl Activity Centers are compared by each of the 

alternatives to display the potential impact to spotted owl breeding sites from noise disturbance 

and other factors associated with motorized use.

• Protected Activity Centers (PACs): PACs are delineated surrounding each territorial spotted owl 

activity center detected since 1986. PACs are delineated to include known and suspected nest 

stands and encompass the best available 300 acres of habitat (2 or more canopy layers, trees in the 

dominant and co-dominant crown classes averaging 24” dbh or greater, at least 70 percent tree 

canopy cover, and in descending order of priority, CWHR classes 6, 5D, 5M, 4D, and 4M and 

other stands with at least 50% canopy cover). The miles of proposed additions to the NFTS and 

the miles of reopened ML 1 roads within spotted owl PACs are compared to determine how the 

various alternatives have the potential to impact nesting spotted owls from noise disturbance and 

other factors associated with motorized use.

• Home Range Core Areas (HRCAs): Delineated California spotted owl Home Range Core Areas 

(HRCAs) are comprised of approximately 1,000 acres (including the PAC) of the best available 

spotted owl habitat (SNFPA 2004). For this analysis, the Home Range Core Area is the 

approximately 700 acres surrounding the ~300 acre core nest area (PAC). HRCAs are delineated 

to represent spotted owl foraging habitat, whereas, PACs are delineated as spotted owl nesting 

habitat. The miles of proposed additions to the NFTS and the miles of reopened ML 1 roads within 

spotted owl HRCAs are compared to determine how the various alternatives have the potential to 

impact foraging spotted owls from noise disturbance and other factors associated with motorized 

use.

Spotted Owl: Direct and Indirect Effects (Disturbance at a Specific Site)

Nest Site or Nest Stand (Within 0.25 Mile Radius Circle of Activity Centers)

Cross Country Travel: Nesting spotted owls would considerably benefit from all the action alternatives 

where 18,535 acres within a 1⁄4 miles radius of a spotted owl activity center (nest site or nest stand) would 
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Tahoe National Forest – 277

be banned from motorized cross country travel, and would have reduced disturbance from motorized 

activities associated with unmanaged, cross country travel. Under Alternative 1, cross country travel 

would be allowed to continue on 18,535 acres (within 1⁄4 mile of spotted owl nest locations), where 

disturbance to spotted owl nesting could occur, potentially altering behavior, causing nest abandonment, 

and resulting in reproductive failure.

Additions to the NFTS: Table 3.03-55 displays the miles of motorized route additions to the NFTS 

within 0.25 of spotted owl activity centers (nest site or nest stand) by spotted owl PAC number and route 

identification number for the action alternatives. The analysis indicates that when considering motorized 

route additions within proximity to known spotted owl nest sites or nest stands, there are far fewer actual 

route miles that would potentially affect nesting owls when compared to looking at motorized route 

additions within the designated spotted owl PAC boundary. The PAC is an administrative boundary that 

was delineated based on the best available 300 acres of habitat surrounding a known spotted owl nest site 

or nest stand.

Alternative 1 clearly poses the greatest risk from noise disturbance to breeding owls by allowing 

motorized cross country travel to continue, including on approximately 41 miles of existing unauthorized

motorized routes. When looking at the immediate area around the actual known nest site, it appears direct 

impacts of disturbance motorized route additions for all the action alternatives are actually quite low.

Alternatives 2, 5, 6, and 7 would result in adding between 0.2 and 0.4 miles motorized routes within 0.25 

miles of a known spotted owl nest site location affecting only 3 PACs (PC138, SI060, and SI030). 

Alternatives 3 and 4 would not add motorized routes near nest sites, and therefore no additional 

disturbance to spotted owl nest site locations would occur. One route (D_49-27_a) is a short spur that 

provides access to a dispersed recreation site. Depending upon the type of dispersed recreational activity 

that occurs in association with this route, increased disturbance to the spotted owl nest site for SI030 has 

the potential to occur.

Table 3.03-55. Miles of Motorized Route Additions within 0.25 miles of Spotted Owl Activity Centers (Nest Site 

or Nest Stand) by PAC Number and Route ID

PAC Number Route ID Number Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Numerous PACs Existing Unauthorized routes 41.1 0 0 0 0 0 0

PC138 ARM-90 0 0 0 0 0 0.2 0

SI060 YRN-2 0 0.2 0 0 0.2 0.2 0.2

SI030 D_49-27_a 0 0.02 0 0 0.02 0.02 0

Total Miles 41.1 0.22 0 0 0.22 0.42 0.20

Reopened ML 1 Roads: As shown in Table 3.03-56, only Alternative 5 proposes to reopen 2.5 miles 

of ML 1 roads within 0.25 miles of known spotted owl nest sites or nest stands. Only Alternative 5 has the 

potential to disrupt or disturb spotted owl nesting from activities associated with motorized use on 

reopened ML 1 roads. The remaining alternatives would not affect nesting spotted owls since they do not 

propose to reopen any ML 1 roads near nesting areas. The amount of disturbance to nesting owls would 

depend on the amount and intensity of use and the type of vehicles used.
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278 – Tahoe National Forest

Table 3.03-56. Miles of Reopened ML 1 Roads within 0.25 Miles of Spotted Owl Activity Center by PAC 

Number and Road Number 

PAC Number ML 1 Road Number Alt 1, 2, 3, 4, 6, 7 Alt 5

NV011 H20-8-5 0 0.1

SI019 N25-18-1 0 0.7

SI032 N33-8 0 0.9

SI033 N39-5 0 0.6

SI033 N39-5-1 0 0.2

Total Miles 0 2.5

Protected Activity Centers

Cross Country Travel: Spotted owl PACs would considerably benefit from all the action alternatives 

where 50,712 acres within PACs would be banned from motorized cross country travel, and thereby 

would have reduced disturbance to nesting spotted owls from motorized activities associated with 

unmanaged, cross country travel. Under Alternative 1, cross country travel on 50,712 acres within PACs 

would continue where disturbance to spotted owl nesting could occur, potentially altering behavior, 

causing nest abandonment, and resulting in reproductive failure.

Additions to the NFTS: Table 3.03-57 displays the miles of motorized route additions to the NFTS 

within PACs by route identification number, and miles of route additions for the action alternatives. The 

proposed additions to the NFTS indicate that Alternatives 2, 5, 6, and 7 would affect between 3 and 6 

PACs, ranging from 0.1 mile to nearly 1 mile. Alternatives 3 and 4 would not affect any PACs since no 

routes within PACs are proposed under these alternatives.

Twelve routes that provide access to dispersed recreation sites potentially affect between 5 and 11 

additional PACS (Alternatives 2 and 5 – the least, Alternative 6 – the most). However, the length of these 

dispersed recreation access routes are generally short spurs that range from less than 0.01 mile to 0.05 

mile. In sum, the dispersed recreation access routes total approximately 0.15 mile for Alternatives 2 and 5, 

and total 0.25 mile for Alternative 6.

Table 3.03-57. Miles of Motorized Route Additions by Spotted Owl PAC and Route ID

PAC Number Route ID Number Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7 

Primary Routes

Intersects 140 PACs

Unauthorized

routes 98

NV034 H29-11 0 0 0 0 0.1 0 0

PC116 ARM-2 0 0.3 0 0 0.3 0.3 0.3

PC138 ARM-90 0 0 0 0 0 0.5 0

SI015 YRN-M3b 0 0.3 0 0 0.3 0 0.3

SI019 H25-18 0 0 0 0 0.3 0 0

SI050 YRN-M2 0 0.1 0 0 0.1 0 0

SI060 YRN-2 0 0.9 0 0 0.9 0.9 0.9

Subtotal 98.1 1.6 0 0 2.0 1.7 1.5
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Tahoe National Forest – 279

PAC Number Route ID Number Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7 

Routes Used to Access Dispersed Recreation Sites

NV003 D_20-12_c 0 0 0 0 0 0.02 0

NV009 D_14_e 0 0 0 0 0 0.01 0

NV009 D_18-14e 0 0 0 0 0 0.02 0

NV010 D_CA-20_a 0 0 0 0 0 0.02 0

NV024 D_20-13 0 0 0 0 0 0.01 0

NV057 D_20-12_g 0 0 0 0 0 0.01 0

NV062 D_843-9_a 0 <0.01 0 0 <0.01 <0.01 0

PC026 D_96-54 0 0.02 0 0 0.02 0.02 0

PC029 D_96_b 0 0 0 0 0 0.02 0

PC044 D_P-6001_b 0 0.05 0 0 0.05 0.05 0

SI030 D_49-27_a 0 0.02 0 0 0.02 0.02 0

YU001 D_Y-125_a 0 0.05 0 0 0.05 0.05 0

Subtotal 0 0.15 0 0 0.15 0.25 0

Total Miles 98.1 1.8 0 0 2.2 2.0 1.5

Table 3.03-58 displays the total miles of motorized route additions to the NFTS within spotted owl 

Protected Activity Centers (PACs), and the number and percentage of PACs affected for each of the 

alternatives. Alternative 1 is clearly a worst case scenario, where cross country motorized travel, 

including use on approximately 98 miles of existing unauthorized routes, would continue to contribute to 

direct and indirect impacts to 140 (77%) spotted owl Protected Activity Centers. Alternative 1 could 

potentially directly and indirectly disturb nesting spotted owls from motorized use on unauthorized

routes.

Alternative 6 would affect the next greatest number of PACs (14 of 181 or 8%) from motorized route 

additions, followed by Alternative 5. Alternatives 5 and 6 each adds approximately 2 miles of motorized 

routes to the NFTS that could contribute to direct and indirect adverse effects to nesting spotted owls

from disturbance associated with motorized vehicle activities. Alternative 2 proposes approximately 2

miles of motorized route additions to the NFTS within 9 PACs (5%).

Alternative 7 would potentially affect 2% or 3 out of 181 Tahoe NF PACs, where less than 2 miles of 

motorized routes would be added to the NFTS. 

Alternatives 3 and 4 do not propose any motorized route additions to the NFTS within spotted owl 

PACs, and therefore, no direct or indirect effects to nesting spotted owls would occur with the 

implementation of Alternatives 3 or 4.
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280 – Tahoe National Forest

Table 3.03-58. Miles of Proposed Motorized route additions to the NFTS within Spotted Owl Protected Activity 

Centers on the Tahoe NF

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Miles of Proposed motorized route additions 98.1 1.8 0 0 2.2 2.0 1.5

Number of Spotted Owl PACs Intersected by motorized route

additions to the NFTS 

140 9 0 0 11 14 3

Percent of PACs Affected by motorized route additions to the 

NFTS (Total Tahoe NF PACs = 181)

77% 5% 0% 0% 6% 8% 2%

Changes to the NFTS-Reopened ML 1 Roads: The miles of reopened ML 1 roads are shown in 

Table 3.03-59 by PAC Number and ML 1 Road number for each of the alternatives. Alternative 5 would 

potentially adversely affect the greatest number of spotted owl PACs (12 of 181 or 7%) from 

approximately 6 miles of reopened ML 1 roads where disturbance to nesting spotted owls has the 

potential to alter behavior, disrupt nesting, and result in reproductive failure. Alternatives 2, 6, and 7 

would be similar in their impacts to nesting spotted owls from reopened ML 1 roads affecting one spotted 

owl PAC (PC096), totaling approximately one mile. Alternatives 1, 3, and 4 would not affect any spotted 

owl PACs, since none of the ML 1 roads are proposed for reopening to motorized use.

Table 3.03-59. Miles of Reopened ML 1 Roads within PACs by Spotted Owl PAC Number and Road Number

PAC Number ML 1 Road Number Alt 1, 3, 4 Alt 2 Alt 5 Alt 6 Alt 7

NV007 H20-3-5-2-3 0 0 0.1 0 0

NV011 H20-8-5 0 0 0.37 0 0

NV060 H613-8 0 0 0.1 0 0

NV064 H20-2 0 0 0.3 0 0

PC031 N33-6 0 0 1.0 0 0

PC031 N96-12c 0 0 0.7 0 0

PC091 H38 0 0 0.1 0 0

PC096 ARM-13 0 0.9 0.9 1.3 0.9

PC114 H45-2 0 0 0.5 0 0

SI019 N25-18-1 0 0 0.6 0 0

SI029 N39-5 0 0 0.1 0 0

SI032 N27-3 0 0 0.2 0 0

SI033 N39-5 0 0 1.2 0 0

SI033 N39-5-3 0 0 0.1 0 0

Totals 0 0.9 6.1 1.3 0.9

Effects to Individual PACs from Route Additions and Reopened ML 1 Roads. The routes 

proposed to be added to the NFTS and the reopened ML 1 roads (converted from closed to open)

contribute a certain amount of disturbance to the activity center on which each PAC is based. Disturbance 

could result in flushing from nests, roosts, or perches, in alarm responses, and in increased stress hormone 

levels in individual spotted owls. In the absence of further research, it is assumed that motorized use 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 281

along all routes within 400 meters (0.25 mile) of activity centers would result in some disturbance to 

nesting owls. Based on that assumption, approximately 2-12% of activity centers would receive some 

disturbance from routes added to the NFTS and/or routes that would be reopened. Without further 

research, this analysis assumes that effects within 60 meters (approximately 60 meters) of an activity 

center will result in negative effects to reproduction over the short term. Therefore, if all the routes 

proposed to be added to the NFTS or proposed to be reopened are further than 400 meters from the 

activity center on which a given PAC is based, it is assumed that the routes under this alternative in that 

PAC would contribute a low level of disturbance to the owls at that activity center. If any of the routes

proposed to be added or reopened are between 60 and 400 meters from the activity center on which the 

PAC is based, it is generally assumed that the routes in that PAC would contribute a moderate level of 

disturbance to the owls at that activity center. Within certain PACs meeting that criterion, the contribution 

to disturbance was rated as low for the reasons given below. If any of the routes proposed to be added or 

reopened are within 60 meters of the activity center, it is assumed that the routes under this alternative in 

that PAC would contribute a high level of disturbance to the owls at that activity center.

For each of the proposed route additions and reopened ML 1 roads, the relative “LEVEL OF 

CONTRIBUTION TO DISTURBANCE” to each PACs “activity center” and supporting rationale is 

shown in Table 3.03-60.
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282 – Tahoe National Forest

Table 3.03-60 Level of Contribution to Disturbance to Spotted Owl by Specific PAC for Route Additions and Reopened ML 1 Roads

PAC 

Number

Route Route 

Addition

Reopened 

ML 1 Road

Length

(miles)

Alternatives Level of 

Contribution to 

Disturbance

Rationale

PC116 ARM-2 X 0.3 Alts 2, 5, 6, 

7

Low Proposed ATV trail located >400 meters (0.54 

miles) from Activity Center, Owls last observed in 

2007

PC138 ARM-90 X 0.5 Alts 2, 5, 7 Moderate Activity Center (2002 pair + fledgling) located <400 

meters (0.1 mi) from north end of route ARM-90.

2007 surveys showed pair detection ~ 1⁄2 mile north 

of proposed route.

SI015 YRN-M3b X 0.3 Alts 2, 5, 7 Low Proposed motorcycle route addition located >400

meters (0.5 mi) east of 1991 Activity Center (pair 

detection). No recent surveys. Route parallels 

eastern boundary of the PAC near the ridge and 

noise would carry across the canyon where owl 

detection located. However, vegetation is dense and 

AC is >400 meters away.

SI019 H25-18 X 0.26 mi Alt 5 Moderate Proposed trail located along southwest boundary of 

PAC, 0.2 mi south of 2007 AC, 2 fledglings in 2007.

SI019 N25-18-1 X Alt 5 Low 2007 surveys indicated Activity Center (adult + 2 

fledglings) located >400 meters (at 0.6 miles) south 

of southern end of route. Historic 1989 Activity 

Center <60 meters of route.

SI029 N39-5 X 1.2 Alt 5 High Route bisects PAC at lower 1/3 and then follows 

eastern PAC boundary. Majority of route located 

less than 60 meters from the Activity Center.

SI030 D_49-27_a X 0.02 Alt 2, 5, 6 Low Short route (0.02 mi) off of existing NFTS road, 

located 0.2 mi. west of Activity Center (single male 

roost site), no documented reproduction.

SI032 N27-3 X 0.2 Alt 5 Low Route located along western PAC boundary, >400 

meters away from Activity Center (Activity Center 

0.3 mi from route). Owls last detected in 2007.

SI033 N39-5 X 1.2 Alt 5 Moderate Route (1 mi) surrounds Activity Center along 3 sides 

and is less than 400 meters away, with risk of 

moderate disturbance due to length of route and 

proximity to Activity Center. Also, increases 

fragmentation to PAC.
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Tahoe National Forest – 283

PAC 

Number

Route Route 

Addition

Reopened 

ML 1 Road

Length

(miles)

Alternatives Level of 

Contribution to 

Disturbance

Rationale

SI033 N39-5-3 X 0.1 Alt 5 Low Short route segment located at southwest edge of 

PAC is >400 meters from Activity Center.

SI050 YRN-M2 X 0.4 (0.1 mi. 

within PAC)

Alt 2 & 5 Moderate Proposed motorcycle trail is located <400 meters 

(0.2 mi) west of known owl observation. Single male 

detected in 1990, no recent survey data. Unknown 

reproductive status and unknown nest location. 

Route parallels nearly entire western boundary of 

PAC 

SI060 YRN-2 X 0.93 Alt 2, 5, 6, 7 Moderate ~1 mile proposed route located 0.23 miles from 

known Activity Center, last known reproduction in 

1992, surveys conducted in 2008 resulted in finding 

no owls.

NV003 D-20-12_C X 0.02 Alt 6 Low Short route (.02 mi) located >1 mi away from Activity 

Center and connects 2 existing NFTS roads, nest 

with young found in 2004.

NV007 H20-3-5-2-3 X 0.1 Alt 5 Moderate Route located <400 meters (0.2 mi north) from 

nearest known owl detection 

NV009 D_14_e X <0.01 Alt 6 Low Short route (<0.01 mi) off of existing NFTS, located 

0.34 mi from known Activity Center.

NV009 D_18-14e X 0.02 Alt 6 Low Short route (0.02 mi) off of existing NFTS, 0.7 mi 

from known Activity Center, successful reproduction 

documented in 2008

NV010 D_CA-20_a X 0.02 Alt 6 Low Short route (0.02 mi) located 0.6 mi. south of 

Activity Center.

NV011 H20-8-5 X 0.3 Alt 5 Low Route >400 meters south of Activity Center, 

however route bisects PAC from one edge of PAC 

to opposite edge of PAC.

NV024 D_20-13 X 0.01 Alt 6 Low Short route (0.01 mi) off of existing NFTS road, 

located >400 meters (0.7 mi north) of AC.

NV034 H29-11 X 0.1 Alt 5 Low Route located 0.45 mi east of private land Activity 

Center, owls last observed in 2004

NV057 D_20-12_g X 0.01 Alt 6 Low Short route (0.01 mi) located >400 meters of activity 

center (route is 0.5 mile south of known Activity 

Center). 
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284 – Tahoe National Forest

PAC 

Number

Route Route 

Addition

Reopened 

ML 1 Road

Length

(miles)

Alternatives Level of 

Contribution to 

Disturbance

Rationale

NV060 H613-8 X 0.06 Alt 5 Low Over 0.8 mile to south of Activity Center, would not 

likely increase disturbance, short segment within 

PAC (0.06 mi).

NV062 D_843-9_a X 0.002 Alt 2, 5, 6 Low Short route (0.002 mi) off of existing system road is 

located 0.4 mi east of Activity Center.

NV064 H20-2 X 0.3 Alt 5 Low Route > 400 meters (0.5 mile away) from 2008 nest 

site

PC026 D-96-54 X 0.02 Alt 2, 5, 6 Low Short route (0.02 mi) off of existing NFTS road 

located 0.8 mi. east of Activity Center.

PC029 D_96_b X 0.02 Alt 6 Low Short route (0.02 mi) located 0.5 mi south of 1992 

nest grove (pair w/ fledgling) & 0.7 mi from 1999 

nest cavity location). 

PC031 N33-6 X 0.1 Alt 5 Low Route located >400 meters (0.9 mi) from 2007 

Activity Center (family group)

PC031 N96-12c X 0.7 Alt 5 Low North end of route proposed for reopening located 

>400 meters (0.36 miles) south of 2007 Activity 

Center (family group).

PC044 D_P-6001_b X 0.05 Alt 2, 5, 6 Low Short route (0.05 mi) comes off of existing NFTS 

road, located 0.5 miles from Activity Center.

PC091 H38 X 0.1 Alt 5 Low Route follows southeast edge of PAC boundary, 

located 0.9 mi from 1991 Activity Center.

PC096 ARM-13 X 0.7 Alt 5, 6, 7 Low ARM-13 located in portion of PAC that burned in 

Government Fire of 2008. 2007 pair location is 0.06 

mi from route within burned area. Habitat where 

route and 2007 pair location is no longer suitable.

PC114 H45-2 X 0.4 Alt 5 Moderate Proposed route (0.4 mi) located at 400 meters away 

from 1994 Activity Center. Route bisects center of 

PAC and lies directly parallel to 2 existing system 

routes. Would increase disturbance in the PAC and 

increase habitat fragmentation.

YU001 D_Y-125_a X 0.05 Alt 2, 5, 6 Low Short route (0.05 mi) comes off of existing NFTS 

road, located 0.4 mile from Activity Center
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Tahoe National Forest – 285

Summary of Individual PAC Analysis

Table 3.03-61 summarizes the potential risk of increased disturbance to spotted owl activity centers (181 

Total TNF PACS), as a result of motorized route additions and reopened ML 1 roads. Alternatives 3 and 4 

would not affect increase disturbance to spotted owls within any PAC, since no routes or reopening of ML 

1 road would be proposed. Alternatives 7, 2, 6, and 5 would potentially increase disturbance to spotted 

owl activity centers within PACs, in increasing order, ranging from approximately 3% to 13%. Only 

Alternative 5 would add routes or reopen ML 1 roads that would result in a “high” risk of increased 

disturbance where a route would be added or reopened ML 1 road would occur within 60 meters (200 

feet) of a spotted owl activity center. The remaining action alternatives would result in either a low or 

moderate risk of increased disturbance from the addition of routes or reopening ML 1 roads. In both the 

low and moderate risk categories, Alternative 5 would result in the most number of PACs (22 of 181 or 

12%) potentially affected by increased disturbance (7 of 181 PACs or 3% @moderate risk, 15 of 181 

PACs or 8% PACs at low risk), followed by Alternative 6 (1 of 181 PACs or <1% @moderate risk, 14 of 

181 PACs or 8% @low risk), Alternative 2 (3 of 181 PACs or 2% @moderate risk, 7 of 181 PACs or 4% 

@low risk), and Alternative 7 (2 of 181 PACs or 1% @ moderate risk, 3 of 181 PACs or 2% @ low risk).
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286 – Tahoe National Forest

Table 3.03-61. California spotted owl: summary of risk of increased disturbance to Activity Centers within PACs

Alt 1 Alt 2 Alt 3, 4 Alt 5 Alt 6 Alt 7

Risk of increased 

disturbance 

effects

Rationale No. 

PACs

% of 

Total

No. 

PACs

% of 

Total

No. 

PACs

% of 

Total

No. 

PACs

% of 

Total

No. 

PACs

% of 

Total

No. 

PACs

% of 

Total

HIGH Route added or reopened ML 1 road

within 60 meters (200 feet) of activity 

center

0 0 0 0% 0 0% 1 0.6% 0 0% 0 0%

MOD Routes added or reopened ML 1 roads 

occurring less than 400 meters (1/4 mi)

and more than 200 feet from activity 

center, and no intervening topography

0 0 3 1.7% 0 0% 7 2.8% 1 0.6% 2 1.1%

LOW All routes added or reopened ML 1 

roads greater than 400 meters from 

activity center.

0 0 7 3.9% 0 0 15 8.3% 14 7.7% 3 1.7%

HIGH PACs where cross country travel 

continued, including on unauthorized 

routes

175 96.7% 0 0% 0 0% 0 0% 0 0% 0 0%

DECREASE Total PACs where a decrease in 

disturbance would occur from the 

prohibition of cross country travel, 

including on unauthorized routes

0 0 175 96.7% 175 96.7% 175 96.7% 175 96.7% 175 96.7%

Total PACs in which routes are added and/or being 

converted from closed ML 1 roads to open

0 0 10 5.5% 0 0% 23 12.7% 15 8.3% 5 2.8%

Total PACs Where cross country travel continued 175 96.7% 0 0% 0 0% 0 0% 0 0% 0 0%

Total PACs with decreased disturbance from the 

prohibition of cross country travel, including on 

unauthorized routes

0 0 175 96.7% 175 96.7% 175 96.7% 175 96.7% 175 96.7%
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 287

Home Range Core Areas (HRCAs)

Cross Country Travel: Spotted owl HRCAs would considerably benefit from all the action alternatives 

where 98,806 acres within HRCAs would be banned from motorized cross country travel, and would 

reduce disturbance to foraging spotted owls from motorized activities associated with motorized cross 

country travel. Under Alternative 1, cross country travel on 98,806 acres within HRCAs would continue 

where disturbance to spotted owl foraging could occur, potentially altering behavior, reducing fitness, and 

potentially affecting reproductive success. 

Additions to the NFTS: Table 3.03-62 displays the miles of motorized route additions and the 

number and percentage of Tahoe NF HRCAs affected by alternative. Clearly Alternative 1 represents a 

worst case scenario for spotted owls when looking at the motorized route effects at the HRCA scale. 

Alternative 1 would potentially affect 164 out of 181 HRCAs (91%) from motorized use on 

approximately 282 miles of existing unauthorized routes. The No Action Alternative definitively could 

result in significant direct and indirect disturbance to foraging spotted owls from continued use of 

unauthorized routes. 

All the remaining action alternatives would significantly reduce the impacts of existing unauthorized 

routes. Alternative 3 would not affect any HRCAs since no routes within HRCAs are proposed, and 

therefore no effects to foraging owls would occur.

The remaining action alternatives would directly and indirectly affect between 5 and 23% spotted owl 

HRCAs, from 6 to 15 miles of motorized route additions. Alternative 6 would affect the greatest number 

and percentage of HRCAs. However, Alternative 5 would result in the next greatest number of miles of 

motorized routes within HRCAs, followed by Alternatives 2, 6, 7, 4, and 3, in descending order.

Table 3.03-63, which displays the motorized miles added by HRCAs and route ID numbers, helps to 

disclose the subtle differences between the action alternatives. When looking at the total miles of routes 

added, Alternative 5 results in adding the greatest number of motorized miles that would potentially affect 

foraging owls within 34 HRCAs, where a total of 15 miles would be added (14 miles added for general 

motorized opportunities, 1 mile added to access 34 dispersed recreation sites). 

Alternative 2 would add the next greatest motorized miles within 31 HRCAs affecting foraging owls, 

where a total of 13 miles would be added (12 miles general use, 1 mile for dispersed sites).

Under Alternative 6, the majority of motorized route additions which intersect HRCAs are routes that 

access dispersed sites (25 out of 41 HRCAs intersected) for a total of about 1 mile. Each of the routes 

accessing these dispersed recreation areas are short spurs that add up to a total over 1 mile. Alternative 6 

would affect 16 HRCAs where increased disturbance to foraging owls would occur from adding about 10 

miles for general motorized use. 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

288 – Tahoe National Forest

Table 3.03-62. Miles of Motorized Route Additions to the NFTS within Tahoe NF Spotted Owl HRCAs

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Miles of motorized route additions 281.7 13.3 0 6.2 14.8 11.0 7.6

Number of HRCAs Intersected by motorized 

route additions to the NFTS 

164 31 0 15 34 41 9

Percent of HRCAs Affected by motorized route 

additions (Total Tahoe NF HRCAs = 181)

91% 17% 0% 8% 19% 23% 5%

*Alternative 1 includes existing unauthorized routes with the continuance of cross country travel.

Table 3.03-63. Miles of Motorized Route Additions by HRCAs and Route ID 

HRCA ID Number Route ID Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

General Routes

Numerous HRCA s Unauthorized 

Routes

281.7 0 0 0 0 0 0

NV012 YRS-SF4 0 0 0 0 0.82 0 0

NV012 H20-16-2-7 0 0 0 0 0.21 0 0

NV015 YRS-B10 0 0.26 0 0 0.26 0 0

NV017 YRS-SF6 0 0 0 0 0.26 0 0

NV017 H29-11 0 0 0 0 0.09 0 0

NV017 YRS-SF6 0 0.32 0 0.32 0.32 0.32 0.32

NV017 YRS-SF6b 0 0.86 0 0.86 0.86 0.86

NV017 YRS-66 0 0.22 0 0 0.22 0.22 0

NV019 YRS-SF4 0 0.82 0 0 0.82 0.82 0

NV019 YRS-SF5 0 0.39 0 0 0.39 0.39 0.39

NV024 YRS-B5 0 2.46 0 0 2.46 2.46 0

NV024 YRS-B10 0 0.26 0 0 0.26 0 0

NV034 YRS-SF5 0 1.82 0 1.82 1.82 1.82 1.82

PC020 ARM-2 0 0.32 0 0 0.30 0.32 0.30

PC082 ARM-3r 0 2.71 0 2.71 2.71 2.19 2.71

SI015 YRN-M3b 0 0.81 0 0 0.81 0 0.81

SI029 491-3-2_p 0 0 0 0 0.05 0.05 0

SI030 H34-8-3 0 0 0 0 0.02 0 0

SI033 491-3-2_p 0 0 0 0 0.05 0.05 0

SI049 YRN-M3b 0 0.20 0 0 0.20 0.20 0

SI050 YRN-M2 0 0.46 0 0 0.46 0 0

SI052 YRN-001 0 0.06 0 0 0.06 0.06 0

SI060 YRN-2 0 0.06 0 0 0.01 0.06 0.06

SI093 YRM-M4 0 0.35 0 0 0.345 0.35 0.35

Subtotal for General Routes 281.7 12.4 0 5.7 13.9 9.8 7.6
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 289

HRCA ID Number Route ID Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Routes that Access Dispersed Recreation Sites

NV057 D_20-9_b 0 0 0 0 0 0.02 0

NV064 D_20-3_b 0 0 0 0 0 0.03 0

NV070 D_41-20-10_a 0 0.02 0 0 0.02 0.02 0

NV070 D_41-20-10_b 0 0.02 0 0 0.02 0.02 0

PC027 D_96-54 0 0.02 0 0 0.03 0.02 0

PC028 D_P88_b 0 <0.01 0 <0.01 <0.01 <0.01 0

PC029 D_96_b 0 0 0 0 0 0.02 0

PC088 D_P88_b 0 <0.01 0 <0.01 <0.01 <0.01 0

PC094 D_96_b 0 0 0 0.03 0

PC096 D_P88_c 0 0.03 0 0.03 0.03 0.03 0

PC097 D_P88_b 0 <0.01 0 <0.01 <0.01 <0.01 0

PC118 D_96_b 0 0 0 0 0 0.03 0

PC0125 D_96_b 0 0 0 0 0 0.03 0

PC141 D_96-54 0 0.02 0 0 0.02 0.02 0

SI001 D_S-300_a 0 0.08 0 0.084 0.08 0.08 0

SI001 D_S-300_b 0 0.01 0 0.012 0.01 0.01 0

SI016 D_11E02_a 0 0.04 0 0 0.04 0.04 0

SI016 D_11E02_b 0 0.08 0 0 0.08 0.08 0

SI021 D_S-514_A 0 0.04 0 0 0.04 0.04 0

SI026 D_S-295_c 0 0.01 0 0.009 0.01 0.01 0

SI026 D_S300_b 0 0.10 0 0.100 0.10 0.10 0

SI031 D_Y-122_a 0 0.02 0 0.022 0.02 0.02 0

SI040 D_9-15_a 0 0 0 0 0 <0.01 0

SI040 D_9-15_b 0 0 0 0 0 0.04 0

SI041 D_5688 0 0 0 0 0 <0.01 0

SI052 D_11E20 0 0 0 0 0 0.01 0

SI056 D_11E02a 0 0.06 0 0 0.06 0.06 0

SI056 D_11E02b 0 0.08 0 0 0.03 0.08 0

SI064 D_S-301_a 0 0.11 0 0.11 0.11 0.11 0

SI089 D_34_b 0 0.01 0 0.008 0.008 0.008 0

SI089 D_34_c 0 0.02 0 0.021 0.021 0.021 0

SI095 D_7-30_b 0 0 0 0 0.016 0

YU018 D_Y-122_a 0 0.02 0 0.022 0.022 0.022 0

YU023 D_Y-122_a 0 <0.01 0 0.003 0.003 0.003 0

YU023 D_Y-122_b 0 0.03 0 0.033 0.033 0.033 0

YU023 D_Y-122_c 0 0.00 0 0.040 0.040 0.040 0

YU023 D_Y-125_a 0 0.054 0 0 0.054 0.054 0
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

290 – Tahoe National Forest

HRCA ID Number Route ID Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

NV003 D_20-12-1a 0 0 0 0 0 0.011 0

NV003 D_20-12-1b 0 0 0 0 0 0.011 0

NV003 D_20-12_b 0 0 0 0 0 0.012 0

NV003 D_20-12_D 0 0 0 0 0 0.009 0

NV003 D_20-9_b 0 0 0 0 0 0.018 0

NV009 D_18-14_e 0 0 0 0 0 0.010 0

NV010 D_20-9_b 0 0 0 0 0 0.018 0

Subtotal for Routes to Dispersed Sites 0 0.93 0 0.49 0.93 1.23 0

Total All Routes 281.7 13.3 0 6.2 14.8 11.0 7.6

Changes to the NFTS-Reopened ML 1 Roads: The miles of reopened ML 1 roads are shown in 

Table 3.03-64 by HRCA ID Number and ML 1 Road Number for each of the alternatives. Alternative 5 

would potentially adversely affect the greatest number of spotted owl HRCAs (19 of 181 or 10% of Tahoe 

NF HRCAs) from approximately 11 miles of reopened ML 1 roads where disturbance to foraging spotted 

owls has the potential to alter behavior, disrupt foraging, and potential affect reproductive success.

Alternatives 6, 2, and 7 would also affect HRCAs used for foraging, from reopened ML 1 roads, but to a

much lesser extent than Alternative 5. Alternative 6 would reopen about 1.5 miles of ML 1 roads within 

HRCAs, followed next by Alternative 2 and 7 with 1 mile and 0.1 mile of ML 1 roads reopened, 

respectively. Alternatives 1, 3, and 4 would not affect any spotted owl HRCAs used for foraging, since 

none of the ML 1 roads are proposed for reopening to motorized use under these alternatives.

Table 3.03-64. Miles of Reopened ML 1 Roads within HRCAs by HRCA ID Number and Road Number 

HRCA ID Number ML 1 Road Number Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

NV006 H20-2 0 0 0 0 1.2 0 0

NV006 H20-2-1 0 0 0 0 0.1 0 0

NV010 H20-8-5 0 0 0 0 0.4 0 0

NV015 YRS-B12 0 0.1 0 0 0.1 0.1 0

NV019 H20-16-2-7 0 0 0 0 0.2 0 0

NV024 YRS-B12 0 0.1 0.1 0.1 0.1 0.1

NV064 H20-2 0 0 0 0 0.9 0 0

NV064 H20-2-1 0 0 0 0 0.1 0 0

PC025 N44-22-8-1 0 0 0 0 <0.1 0 0

PC031 N33-8 0 0 0 0 0.3 0 0

PC031 N96-12c 0 0 0 0 0.4 0 0

PC091 H38 0 0 0 0 0.2 0 0

PC096 ARM-13 0 0 0 0 0 0.2 0

SI014 N35-10 0 0 0 0 0.6 0 0

SI014 N25-15-2 0 0 0 0 0.2 0 0

SI019 N25-18-1 0 0 0 0 0.5 0 0

SI019 N27-9 0 0 0 0 0.1 0 0
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 291

HRCA ID Number ML 1 Road Number Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

SI020 N25-19-1 0 0 0 0 0.2 0 0

SI024 N25-2 0 0 0 0 0.1 0 0

SI024 N25-4-2 0 0 0 0 0.4 0 0

SI024 N25-4-2-2 0 0 0 0 <0.1 0 0

SI029 N39-5 0 0 0 0 0.4 0 0

SI029 N39-7 0 0 0 0 0.1 0 0

SI029 491-3_p 0 0 0 0 0.2 0.2 0

SI032 N27-3 0 0 0 0 0.5 0 0

SI032 N27-4 0 0 0 0 <0.1 0 0

SI032 N27-5 0 0 0 0 <0.1 0

SI033 N39-5 0 0 0 0 1.2 0

SI033 N39-5-1 0 0 0 0 0.2 0

SI033 N39-5-2 0 0 0 0 0.4 0

SI033 N39-5-4 0 0 0 0 0.2 0

SI033 N39-6 0 0 0 0 <0.1 0

SI033 N39-7 0 0 0 0 <0.1 0

SI033 491-3_p 0 0 0 0 0.2 0.2 0

SI064 H301-6 0 0 0 0 0.7 0

SI095 SV-005 0 0.6 0 0 0.6 0.6 0

Total Miles 0 0.8 0 0 10.9 1.5 0.1

Cumulative Effects to Nesting Spotted Owl 

Cumulative Effects Boundary (space and time)

The cumulative density of motorized routes increases within the larger cumulative effects analysis area 

that includes private lands within the Forest. The cumulative effects geographic boundary for the 

California spotted owls includes all spotted owl Protected Activity Centers and their associated Activity 

Centers (nest site or nest stand) within the boundary of the Tahoe NF. This is an appropriate scale for 

determining cumulative effects to spotted owls, since the Tahoe NF boundary is sufficiently large which 

includes 181 spotted owl territories and their home ranges across the Forest. In addition, the Tahoe NF 

boundary encompasses an array of spotted owl habitat conditions from low elevation to high elevation, 

including several vegetation types from westside mixed conifer, ponderosa pine, true fir, and eastside 

mixed conifer. The cumulative effects timeframe is the same as other species: 20 years out into the future 

and approximately 20 years or more into the past.

General Cumulative Effects of Past and Future Vegetation Management Projects and Wildfires

Appendix H (Reasonably Foreseeable Projects and Cumulative Effects) provides a list and description of 

past, present, and reasonably foreseeable projects on Forest Service system lands and private lands within 

the Tahoe NF boundary. Some, but not all, of these activities will contribute to impacts to the California 

spotted owl within the cumulative effects boundary. In its Notice of Finding on a petition to list the 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

292 – Tahoe National Forest

California spotted owl, the U.S. Fish and Wildlife Service indicated that loss of habitat to stand replacing 

wildfires and habitat modification for fuels reduction were the primary risk factors to California spotted 

owls occurring on NFS lands (USDI Fish and Wildlife Service 2006). 

Between 1994 and 2008, wildfires resulted in burning 7,312 acres of spotted owl habitat (2,643 PAC 

acres; 4,669 HRCA acres outside PACs) affecting 24 spotted owl territories. 

High and moderate severity burn areas generally resulted in a loss of habitat or a reduction in habitat 

quality. For example, within the 2001 Star Fire at least one spotted owl territory PAC was severely burned 

and the habitat was rendered unsuitable for nesting. Other spotted owl territories have experienced low 

severity burns and resulted in maintaining suitable nesting habitat conditions.

Since 1990, more than 130,000 acres of vegetation management activities have occurred on the Tahoe 

NF. Some, but not all have resulted in impacts to spotted owl habitats. Between 2001 and 2008, about 

17,000 acres of forest vegetation and fuels thinning and mastication projects were completed, which were 

designed to reduce the risk of additional habitat loss to wildfires. These treatments generally do not result 

in habitat removal, but may result in habitat quality changes. Between 1960 and present, private land 

harvest within the boundaries of the Tahoe NF has resulted in over 87,000 acres of vegetation treatments 

including clearcuts, sanitation, shelterwood, and thinning. Much of the private land harvest has resulted in 

the loss or reduction in spotted owl habitat. These wildfires and vegetation treatment projects have 

resulted in a reduction in the amount and quality of spotted owl habitat on the Tahoe NF since 1960. 

Thinning projects designed to reduce hazardous fuels will continue to be the primary activity 

affecting spotted owl habitat on the Tahoe (see Appendix H, Reasonably Foreseeable Projects and 

Cumulative Effects). Although these treatments may reduce habitat quality (i.e. nesting habitat reduced to 

foraging habitat), it expected that suitable habitat will be maintained, and it is anticipated that these 

treatments will reduce the amount spotted owl habitat potentially lost from future stand replacing 

wildfires (USDA Forest Service 2004). The California Department of Forestry and Fire Protection 

currently lists approximately 12,000 acres of private land within the Tahoe NF administrative boundary 

for which timber harvest plans have been submitted. Timber harvest on private lands is generally more 

intensive and does not typically maintain habitat in a suitable condition for spotted owls.

Assessing Cumulative Effects from Motorized Route Additions and Reopened ML 1 Roads

Cumulative effects to breeding spotted owls are assessed by determining the sum total miles of all

motorized routes (existing, additions, and reopened) and non-motorized routes on the Tahoe NF including 

NFS lands and non-NFS lands (private) within spotted owl PACs and within 0.25 mile radius of spotted 

owl Activity Centers. For each alternative, cumulative effects are calculated by adding the total miles of 

proposed motorized route additions and reopened ML 1 roads (direct and indirect impacts) to the existing 

motorized routes (NFS lands and non-NFS lands) and non-motorized routes, then subtracting any routes 

that are either classified as “unauthorized routes” or “decommissioned.” Unauthorized motorized routes

and decommissioned routes are subtracted from the total of all motorized routes because these routes 

would not receive motorized use, and therefore would not contribute to noise disturbance to breeding 

spotted owls. Although non-motorized routes are likely to have lesser impacts to spotted owls compared 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 293

to motorized routes, non-motorized routes are included in this analysis because non-motorized routes 

potentially may pose some level of disturbance to nesting owls depending on the level and duration of use 

during the breeding season.

Nest Site or Nest Stand (Within 0.25 mile Radius of Activity Centers)

When analyzing the cumulative route effects within the 0.25 mile radius circle of spotted owl activity 

centers (nest site or nest stand), it can be noted that a similar theme emerges as compared to the 

cumulative effects within spotted owl PACs. Alternative 1 has the most cumulative miles (124 miles) of 

motorized and non-motorized routes compared to the rest of the alternatives (range 83 to 86 miles) (Table 

3.03-65). Of the action alternatives, Alternative 5 has the next highest cumulative route miles of 86 miles, 

where 0.2 miles are the result of motorized route additions and 2.5 miles are the result of reopened ML 1 

roads. The remaining action alternatives each approximately have about 83 cumulative route miles within 

the 0.25 mile radius analysis circle. However, Alternatives 2, 6, and 7 would result in adding from 0.2 to 

0.4 miles of motorized routes within the 0.25 mile radius circle. Alternatives 3 and 4 would not result in 

adding or reopening motorized routed, and therefore would have no effect on nesting spotted owls within 

0.25 miles of the activity centers.

The potential for cumulative route effects to an owl nest site or nest grove site is very low for all the 

action alternatives; therefore, it can be concluded that implementing any of the action alternatives would 

have no or only minimal additional cumulative impact to nesting spotted owls across the Tahoe NF 

compared to Alternative 1. Alternative 1 clearly poses the greatest cumulative risk to nesting spotted owls 

by allowing continued cross country motorized travel, including motorized travel on approximately 41

miles of existing unauthorized motorized routes, followed by Alternative 5, which proposes to increase 

motorized route miles by about 3 miles within 0.25 miles of spotted owl activity centers, which may 

disturb, disrupt and cause nest failure.

All of the action alternatives would prohibit motorized cross country travel on 18,535 acres within a 

0.25 mile radius of spotted owl activity centers (nest site or nest stand), where the potential for direct 

disturbance and habitat fragmentation within close proximity to nesting owls would be reduced.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

294 – Tahoe National Forest

Table 3.03-65. Cumulative Miles of Routes within a .25 Mile Radius Circle of Spotted Owl Activity Centers 

(Nest/Roost Sites)

Route Miles Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Direct and Indirect effects of proposed alternatives

Motorized Route additions (negative impact)1 41.1 0.2 0 0 0.2 0.4 0.2

Reopened ML 1 roads (negative impact) 0 0 0 0 2.5 0 0

Unauthorized routes where cross country travel would 

be prohibited (positive impact)

0 40.9 41.1 41.1 38.4 40.7 40.9

Cumulative effects of past, present, and proposed actions

Existing motorized routes - NFS lands (negative 

impact)

62.4 62.4 62.4 62.4 62.4 62.4 62.4

Existing routes on non-NFS lands (private) (negative 

impact) 12.5 12.5 12.5 12.5 12.5 12.5 12.5

Existing non-motorized routes (negative impact) 8.3 8.3 8.3 8.3 8.3 8.3 8.3

Existing Closed routes (positive impact) 2.6 2.6 2.6 2.6 2.6 2.6 2.6

Decommissioned routes (positive impact) 2.7 2.7 2.7 2.7 2.7 2.7 2.7

Net Cumulative Effect2

Miles of All Motorized Routes (overall negative 

impacts)2 124.3 83.4 83.2 83.2 85.9 83.6 83.4

1 Alternative 1 includes existing unauthorized routes associated with the continuance of cross country travel.

2 Net Cumulative Impact = Sum Total of Impacts both positive and negative

Cumulative Effects to Nesting Owls within Protected Activity Centers

When considering the cumulative effects of all motorized and non-motorized routes on both NFS lands 

and non-NFS lands, Alternative 1 has the greatest cumulative miles of routes (294 miles) within spotted 

owl PACs on the Tahoe NF, and therefore poses the greatest overall potential risk and cumulative impacts 

to breeding spotted owls on the Tahoe NF (Table 3.03-66) (Figure 3.03-4). Alternative 1 exceeds all the 

action alternatives in the number of cumulative route miles by approximately 80-100 miles. Given the 

magnitude of potential effects upon spotted owl nest sites and habitat, and considering the projections for 

future increases in recreation uses and OHV activity, Alternative 1 may, over time, contribute to 

cumulative effects upon spotted owl distribution and abundance, and ultimately may affect population 

numbers. Because Alternative 1 does not prohibit motorized cross country travel on 50,712 acres of 

spotted owl PACs, it is expected that cumulative effects to spotted owl PACs would increase due to 

unmanaged cross country travel in the future.

Alternative 5 would have the next highest cumulative impacts to breeding spotted owls, resulting in 

214 miles within spotted owl PACs. Alternatives 2, 6, and 7 would have similar route miles and slightly 

fewer miles than Alternative 5. Alternatives 3 and 4 do not add to existing cumulative impacts, since no 

motorized routes within PACs are proposed to be added to the NFTS. All the action alternatives would 

benefit from the ban of motorized cross country travel on total of 52,790 acres within spotted owl PACs 

(2,078 existing prohibitions, 50,712 proposed prohibitions). 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 295

Table 3.03-66. Cumulative Miles of Motorized and Non-motorized Routes within Spotted Owl Protected 

Activity Centers

Cumulative Miles Alt 11 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Direct and Indirect effects of proposed alternatives

Motorized Route Additions (negative impact)1 98.1 3.2 0 0 12.5 2.5 2.3

Reopened ML 1 Roads (negative impact) 0 0.9 0 0 6.1 1.3 0.9

Cross Country Travel Prohibition on Unauthorized

routes (positive impact)

5.7 101.0 103.8 103.8 95.5 100.5 101.3

Cumulative effects of past, present, and proposed actions

Existing Routes on NFS lands (negative) 161.4 161.4 161.4 161.4 161.4 161.4 161.4

Existing Routes on non NFS lands (private) (negative) 12.8 12.8 12.8 12.8 12.8 12.8 12.8

Non-motorized routes (negative) 21.2 21.2 21.2 21.2 21.2 21.2 21.2

Decommissioned Routes (positive) 7.0 7.0 7.0 7.0 7.0 7.0 7.0

Net Cumulative Effect2

Total Miles (overall cumulative effect) 293.5 199.5 195.4 195.4 214.0 199.2 198.6

1

Alternative 1 includes existing unauthorized motorized routes associated with the continuance of cross country travel.

2 Net Cumulative Impact = Sum Total of Impacts both positive and negative

Figure 3.03-4. Cumulative Motorized Miles in Spotted Owl PACs

Cumulative Effects to Foraging Spotted Owls within Home Range Core Areas

Under Alternative 1, the cumulative effects of all motorized and non-motorized routes on both NFS lands 

and non-NFS lands, has the greatest cumulative miles of routes 761 miles) within spotted owl HRCAs on 

the Tahoe NF, and therefore poses the greatest overall potential risk and cumulative impacts to foraging 

Spotted Owl Protected Activity Centers

0

50

100

150

200

250

300

350

1 2 3 4 5 6 7

Alternatives

Miles

PAC Miles
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

296 – Tahoe National Forest

spotted owls on the Tahoe NF (Table 3.03-67) (Figure 3.03-5). Alternative 1 exceeds all the action 

alternatives in the number of cumulative route miles by approximately 256 to 282 miles. Given the large 

extent of potential adverse direct and indirect effects to spotted owls and their foraging habitat within 

HRCAs, and considering the estimates for future increases in recreation uses and OHV activity, 

Alternative 1 may, over time, contribute to cumulative adverse effects upon spotted owl distribution and 

abundance, and may ultimately result in downward population numbers. Because Alternative 1 does not 

prohibit motorized cross country travel on 98,806 acres within spotted owl HRCAs on the Tahoe NF, it is 

expected that adverse cumulative effects to spotted owl HRCAs would increase due to unmanaged cross 

country travel in the future, and may affect spotted owls ability to forage successfully and thrive.

Alternative 5 would have the next highest cumulative impacts from disturbance and habitat 

fragmentation to foraging spotted owls, resulting in 505 cumulative miles within spotted owl HRCAs. In 

descending order, Alternatives 2, 6, 7, 4, and 3 would result in slightly fewer cumulative miles within 

HRCAs than Alternative 5, ranging from 493 to 479 miles. All the action alternatives would substantially 

benefit from the ban of motorized cross country travel on total of 104,365 acres within spotted owl

HRCAs (5,559 existing prohibitions, 98,806 proposed prohibitions). 

Table 3.03-67. Cumulative Miles of Motorized and Non-motorized Routes within Spotted Owl Home Range 

Core Areas

Cumulative Miles Alt 11 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Direct and Indirect effects of proposed alternatives

Motorized Route Additions (negative impact)1 281.7 13.3 0 6.2 14.8 11.0 7.6

Reopened ML 1 Roads (negative impact) 0 0.8 0 0 10.9 1.5 0.1

Cross Country Travel Prohibition on Unauthorized routes 

(positive impact)

0 267.6 281.7 275.5 256.0 269.2 274.0

Cumulative effects of past, present, and proposed actions

Existing Routes on NFS lands (negative) 413.5 413.5 413.5 413.5 413.5 413.5 413.5

Existing Routes on non NFS lands (private) (negative) 18.1 18.1 18.1 18.1 18.1 18.1 18.1

Non-motorized routes (negative) 47.5 47.5 47.5 47.5 47.5 47.5 47.5

Decommissioned Routes and Closed ML 1 Roads 

(positive) 

28.3 28.3 28.3 28.3 28.3 28.3 28.3

Net Cumulative Effect2

Total Miles (overall cumulative effect) 760.8 493.2 479.1 485.3 504.8 491.6 486.8

1

Alternative 1 includes existing unauthorized motorized routes associated with the continuance of cross country travel.

2 Net Cumulative Impact = Sum Total of Impacts both positive and negative
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 297

Figure 3.03-5. Cumulative Motorized Miles in Spotted Owl HRCAs

Summary of Cumulative Effects to Nesting and Foraging Spotted Owls from Disturbance at a 

Specific Site

An analysis of breeding spotted owls on the Tahoe NF at three scales (within 0.25 miles of activity 

centers, within PACs, and within HRCAs), indicates that cumulative effects are considerably greater in 

Alternative 1 (No Action) compared to all the other action alternatives. In addition, under Alternative 1, 

unmanaged cross country motorized travel would continue to occur, and could adversely affect the 

distribution and abundance of spotted owl populations on the Tahoe NF. Under all of the other 

alternatives, cross country motorized travel would be prohibited. All the action alternatives affect nesting 

and foraging spotted owls similarly, where cumulative effects at the forest-wide scale is minimal. When 

comparing only the action alternatives, Alternative 5 poses slightly greater cumulative effects from the 

proposed actions, followed by Alternatives 2, 4, 6, 7, 4, and 3 in descending order.

Site-specific cumulative impacts to spotted owls from the action alternatives could adversely affect

the distribution and abundance of owls at a local level, particularly where motorized route density is 

already high, habitat fragmentation has occurred from past timber harvesting, and urban encroachment is 

a threat. Such is the case in the Burlington Ridge area. The Burlington Ridge area encompasses 

approximately 24,000 acres and provides habitat either wholly or partially for thirteen spotted owl 

territories. Spotted owls in this area are densely concentrated and have been subjected to increasing OHV 

Cumulative Miles within Spotted Owl 

Home Range Core Areas

0

100

200

300

400

500

600

700

800

1 2 3 4 5 6 7

Alternatives

Miles

Cumulative Miles
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

298 – Tahoe National Forest

use in recent years. In addition, the area is in mixed private and federal ownership. Past timber harvest on 

both private and federal lands has significantly altered spotted owl habitat in the Burlington Ridge area.

The Travel Management EIS would generally reduce the effects to spotted owls in the Burlington area by 

prohibiting cross country travel on approximately 33 to 45 existing unauthorized routes. Routes added to 

the NFTS under the alternatives include routes accessing dispersed sites to routes used for OHV use and 

routes for motorcycle use. One route of particular concern (YRS-B5 - Deer Creek Forebay trail) is 

approximately 4 miles in length and is located in an HRCA and is in an area densely concentrated by 

spotted owls. Habitat availability in the Burlington Ridge area is a limiting factor since several owl 

territories overlap. YRS-B5 proposed under Alternatives 4, 5, and 6 would add the most motorized miles 

potentially increasing noise related disturbance, and could cumulatively affect the long-term productivity 

and distribution of owls in the vicinity. In addition, the Burlington Area currently has high existing 

motorized route density, including both existing roads and motorized trails. Use of the Burlington Ridge 

area is popular with motorcycle users and the close proximity to the town of Nevada City poses a concern 

to spotted owls from human associated disturbance, since access is easy. Alternative 1 would be the worst

case scenario where approximately 45 miles of motorized use would continue on existing unauthorized 

routes, which equates to approximately 1/3 more routes than the action alternatives. Due to the potential 

increasing use of the Burlington Ridge area, future cumulative effects under Alternative 1 could be 

significant.

Spotted Owl Habitat Fragmentation and Edge Effects

Indicators used to Measure Effects

Cross Country Travel: Motorized cross country travel is evaluated for the alternatives to determine the 

effects on spotted owl habitat fragmentation within PACs and HRCAs.

Zone of Influence within PACs and HRCAs: In addition to determining the habitat fragmentation 

within CWHR types 4M, 4D, 5M, 5D, and 6, described previously, zones of influence were determined 

within spotted owl PACs and HRCAs within 200 meters of motorized route additions and reopened ML 1 

roads. Three ZOI were analyzed in the DEIS and are available in the project record. However, all effects 

identified in the 60 m and 100 m ZOI are also identified in the 200 m ZOI and therefore provide little 

additional information. Thus the analysis presented here is shortened to display only the 200 m ZOI. 

Direct and Indirect Effects

Zone of Influence within PACs

Habitat fragmentation and edge effects were described for old forest coniferous associated species within 

old forest coniferous forest types (CWHR types 4M, 4D, 5M, 5D, and 6) and within Old Forest Emphasis 

Areas (OFEAs) under the section “Effects Common to All Old Forest Coniferous Associated Species.” 

Those analyses provided a forest-wide view of how the alternatives affect spotted owl habitat 

fragmentation within old forest coniferous habitats and OFEAs. This section provides a focused analysis 

of spotted owl habitat fragmentation and edge effects (including noise disturbance) from motorized routes 

at the site-specific PAC scale, where known spotted owl nest territories are located.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 299

Spotted owl Protected Activity Centers (PACs) are delineated land allocations (SNFPA 2004), 

comprised of the best available spotted owl habitat, which are managed specifically for sustaining viable 

populations of spotted owls. For all spotted owl PACs on the Tahoe NF, the effects of the alternatives are 

analyzed for the amount of habitat fragmentation and edge effects occurring by considering the Zone of 

Influence within PACs within 200 meters of motorized additions and reopened ML 1 roads (Table 3.03-

68). The 60 meters Zone of Influence represents habitat fragmentation to the spotted owl as it relates to 

habitat components, such as snag and down log removal along routes for public fuelwood and public 

safety hazards. Absolute noise disturbance thresholds for California spotted owls have not been 

established, but the best available science indicates that 100 meters and 200 meters may be important 

noise disturbance thresholds for spotted owls and other birds of prey (Delaney 1999, Delaney and Grubb 

2001, Delaney and Grubb 2003). 

Additions to the NFTS and Reopened ML 1 Roads: The Zone of Influence at 200 meters of 

motorized route additions and reopened ML 1 roads within PACs are shown in Table 3.03-64 for the 

alternatives. Alternative 1 would reduce habitat effectiveness for spotted owls considerably within 22% of 

PAC acres on the Tahoe NF. Alternatives 2, 5, 6, and 7 would reduce habitat effectiveness within PACs by 

1% or less from motorized route additions. Alternatives 3 and 4 would not affect overall habitat 

effectiveness of spotted owl PACs since no motorized routes would be added to the NFTS within PACs.

The effect of reopening ML 1 roads is only proposed under Alternative 5 where an additional 1% of 

spotted owl PACs would be subject to motorized activities, potentially reducing habitat effectiveness for 

nesting owls. However, the amount of overall reduced habitat effectiveness resulting from reopened ML 1 

roads across the Forest is likely to be benign at the Forest scale.

Table 3.03-68. Proportion of Spotted Owl PACs within 200 Meters of Motorized Route Additions and 

Reopened ML 1 Roads

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Percent of spotted owl PACs within ZOI of Route Additions 22% 1% 0% 0% 1% 1% 1%

Percent of spotted owl PACs within ZOI of Reopened ML 1 

Roads

0% 0% 0% 0% 1% 0% 0%

*Alternative 1 includes existing unauthorized routes with the continuance of cross country travel.

Cumulative Effects to Habitat Fragmentation and Edge Effects

within California Spotted Owl PACs

Zone of Influence at 200 meters

Cumulative effects of habitat fragmentation within California spotted owl PACs were assessed by 

determining the amount of spotted owl PACs that are influenced by all routes including both motorized 

and non-motorized routes on NFS lands and non-NFS lands. The Zone of Influence at 200 meters was 

used to determine potential habitat fragmentation from the influence of noise, edge effects, and habitat 

alteration associated with motorized and non-motorized routes.

Table 3.03-69 displays the cumulative effects of the proposed alternatives from all motorized and 

non-motorized routes on NFS and non-NFS lands. When comparing the cumulative effects of routes to 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

300 – Tahoe National Forest

spotted owl PACs within a 200 meter Zone of Influence (by summing the direct and indirect effects of the 

alternatives and the cumulative effects of past, present, and future actions), Alternative 1 has the greatest 

overall cumulative impact (cumulative impact score = 57%) and, therefore, poses the greatest risk to 

habitat connectivity and other negative cumulative impacts (including noise disturbance) associated with 

continued motorized cross country travel, including use of existing unauthorized routes within spotted 

owl PACs. In addition, Alternative 1 would contribute to route proliferation because unmanaged cross 

country motorized travel would continue into the future. Implementing Alternative 1 poses the greatest 

concern to habitat fragmentation to spotted owl habitat within PACs.

Alternative 5 has the second greatest contribution to overall cumulative impacts within PACs 

(cumulative impact score = 37%), due to the percentage of acres (2%) impacted by proposed additions 

and reopened ML 1 roads. Alternatives 3 and 4 do not add to existing cumulative effects, since no 

motorized routes within PACs would be added to the NFTS. Alternatives 2, and 6, affect 1% spotted owl 

habitat within 200 meters of PACs. In addition, cross country travel including use on existing 

unauthorized routes would be prohibited under all the action alternatives.

Table 3.03-69. Cumulative Effects - Proportion of Spotted Owl Protected Activity Centers within 200 meter 

Zone of Influence of All Routes

Alt 11 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Direct and Indirect effects of proposed alternatives

Motorized Route Additions (negative impact)1 22% 1% 0% 0% 1% 1% 1%

Reopened ML 1 Roads 0% 0% 0% 0% 1% 0% 0%

Unauthorized Routes Where Cross Country Travel would be 

Prohibited (postive impact)

0% 22% 23% 23% 21% 22% 23%

Cumulative effects of past, present, and proposed actions

Existing motorized routes - NFS lands (negative impact) 27% 27% 27% 27% 27% 27% 27%

Existing routes on non-NFS lands (private) (negative impact) 5% 5% 5% 5% 5% 5% 5%

Existing non-motorized routes (negative impact)2 3% 3% 3% 3% 3% 3% 3%

Decommissioned or Existing Closed routes (positive impact) 2% 2% 2% 2% 2% 2% 2%

Total Cumulative Effects

Overall Cumulative Effects (total of all impacts,

both positive and negative)

57% 36% 35% 35% 37% 36% 36%

1 Alternative 1 includes existing unauthorized routes associated with the continuance of cross country travel.

2 Non-motorized -assumption made that non-motorized impact is limited to 60 meters from trail and that no impact occurs beyond 60 

meters

Direct and Indirect Effects to Fragmentation and Edge Effects

within Home Range Core Areas (HRCAs)

Cross Country Travel: Alternative 1 poses the greatest risk to spotted owls within spotted owl Home 

Range Core Areas (HRCAs), where cross country motorized travel would continue and proliferate on 

98,806 acres. The action alternatives would benefit spotted owls from reduced habitat fragmentation and 

disturbance from the ban of cross country travel on 98,806 acres.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 301

Additions to the NFTS and Reopened ML 1 Roads (Zone of Influence): To evaluate habitat 

fragmentation, noise disturbance, and edge effects on spotted foraging habitat within HRCAs, the Zone of 

Influence of motorized route additions and reopened ML 1 roads within spotted owl HRCAs was 

determined for each alternative within 200 meters (Table 3.03-70).

Alternative 1 reduces habitat effectiveness for spotted owls considerably where the percentage of 

HRCAs on the Tahoe NF affected is 22% influenced by existing unauthorized routes. 

All the action alternatives would enhance habitat effectiveness within HRCAs by prohibiting cross 

country travel on the majority of existing unauthorized routes. When comparing all the action alternatives, 

Alternative 5 would contribute to about a 2% reduction in habitat effectiveness within HRCAs from route 

additions and reopened ML 1 roads combined. Alternatives 2 and 6 reduce habitat effectiveness within 

HRCAs by 1% from motorized route additions, but would not affect HRCAs from reopening ML 1 roads.

Alternatives 4 and 7 only add about 0.5% direct and indirect effects to HRCAs, and would not pose 

concern to foraging owls at the Forest-wide scale. Alternative 3 would not affect overall habitat 

effectiveness within spotted owl HRCAs at a 200 meter Zone of Influence. Except for Alternative 3, the

remaining action alternatives would only contribute to a very small amount of reduced habitat 

fragmentation at the Forest-wide scale. However, when specific HRCAs are considered, it becomes 

apparent that individual spotted owl territories would result in habitat fragmentation from adding routes 

and reopening ML 1 roads within HRCAs, as shown in Tables 3.03-63 and 64. For example, the HRCA 

for spotted owl territory NV017 would be affected by 6 different route additions totaling between 0.5 and 

1.7 miles. Additions of motorized routes within spotted owl territories, such as NV017 and NV024 in the 

Burlington Ridge area would result in direct and indirect impacts to spotted owls foraging in the area 

through increased noise and disturbance, and long-term habitat fragmentation.

Table 3.03-70. Proportion of California Spotted Owl Home Range Core Areas (HRCAs) within 200 Meters 

influenced by Motorized Route Additions and Reopened ML 1 Roads

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Percent of HRCAs within Zone of Influence of Motorized 

Route Additions 22% 1.2% 0 0.5% 1.3% 1.2% 0.5%

Percent of HRCAs within Zone of Influence of Reopened ML 

1 Roads

0% 0% 0% 0% 1% 0% 0%

Alternative 1 includes existing unauthorized routes associated with the continuance of cross country travel.

Cumulative Effects to HRCAs

Cross Country Travel: Alternative 1 would significantly add to adverse cumulative effects within 

spotted owl HRCAs, and would potentially disturb nesting and foraging spotted owls and fragment 

suitable spotted owl habitat since on cross country would continue on 98,806 HRCA acres because 

unmanaged cross country motorized travel would continue and proliferate into the future. Alternative 1 

would limit cross country travel on 5,559 acres that are currently closed to motorized use under the 

existing LMP standards and guidelines. Whereas all the action alternatives would benefit spotted owls 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

302 – Tahoe National Forest

within HRCAs by prohibiting cross country travel on an additional 98,806 acres, which would greatly 

reduce habitat fragmentation and disturbance from motorized use. 

Additions to the NFTS and Reopened ML 1 Roads (Zone of Influence): The cumulative effects to 

spotted owl HRCAs within a 200-meter Zone of Influence are compared for the proposed alternatives 

(Table 3.03-71). As previously discussed, the cumulative effects analysis presented here only provides a 

relative comparison of cumulative effects to spotted owl foraging habitat from motorized and nonmotorized routes.

When comparing the cumulative effects of routes to HRCAs within a 200 meter Zone of Influence

(by summing the direct and indirect effects of proposed alternatives and the cumulative effects of past, 

present, and future actions), Alternative 1 has the greatest overall cumulative impact (cumulative impact 

score = 58%) and, therefore, poses the greatest risk to habitat connectivity and other negative cumulative 

impacts (including noise disturbance) associated with routes within spotted owl HRCAs. Overall 

cumulative effects of the action alternatives are similar (cumulative impact scores range from 36% to 

38%). With the exception of Alternative 3, the action alternatives all slightly add to cumulative impacts, 

where 1-2% of HRCA acres would be influenced by the addition of motorized routes to the NFTS and 

reopened ML 1 roads (Alt 5 only). Although the action alternatives would only result in adding a small 

percentage of cumulative impacts to Tahoe NF HRCAs from motorized route additions or reopened ML 1 

roads, individual owl territories could receive adverse cumulative impacts, particularly in areas such as 

Burlington Ridge on the Yuba River Ranger District where cumulative effects to spotted owls are already 

high from motorized activities associated with the Burlington Ridge trail system, existing motorized 

routes, and past vegetation management.

Alternative 3 would not add to cumulative effects, since no motorized routes would be added to the 

NFTS nor would ML 1 roads would be reopened. Finally, all cross country travel would be prohibited on 

98,806 HRCA acres, including the use on existing unauthorized motorized routes that affect 

approximately 11% of HRCAs within Alternatives 2, 3, 4, 5, 6, and 7.

Table 3.03-71. Cumulative Effects - Proportion of California Spotted Owl Home Range Core Areas (HRCAs) 

within a 200-meter Zone of Influence

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Direct and Indirect effects of proposed alternatives

Proposed motorized route additions to NFTS (negative 

impact)1 22% 1.2% 0 0.5% 1.3% 1.2% 0.5%

Reopened ML 1 Roads 0% 0% 0% 0% 1% 0% 0%

Cross country travel prohibited on existing unauthorized

routes (positive impact)

0% 21% 22% 21% 20% 21% 21%
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 303

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cumulative effects of past, present, and proposed actions

Existing motorized routes - NFS lands (negative impact) 27% 27% 27% 27% 27% 27% 27%

Existing routes on non-NFS lands (private) (negative impact) 5% 5% 5% 5% 5% 5% 5%

Existing non-motorized routes (negative impact)1 4% 4% 4% 4% 4% 4% 4%

Decommissioned routes and Closed ML 1 roads (positive 

impact)

3% 3% 3% 3% 3% 3% 3%

Total Cumulative Effects

Overall Cumulative Effects equals the total of all 

impacts, both positive and negative

58% 37% 36% 37% 38% 37% 37%

1 Motorized route Additions - Alternative 1 includes existing unauthorized routes associated with the continuance of cross country 

travel.

2 Non-motorized -assumption made that non-motorized impact is limited to 60 meters from trail and that no impact occurs beyond 60 

meters

Cumulative Effects Summary of Habitat Fragmentation and Edge Effects

within Spotted Owl HRCAs

The proportion of spotted owl Home Range Core Areas (HRCAs) within a 200-meter Zone of Influence

of all motorized and non-motorized within NFS and non-NFS were determined in order to assess the 

cumulative effects from the proposed alternatives. Alternative 1 poses the greatest cumulative effects 

within spotted owl HRCAs that would be used for foraging spotted owls from route associated factors 

including noise, edge effects, and habitat fragmentation. Alternative 1 affects approximately 22% of 

spotted owl HRCAs within a 200-meter Zone of Influence, respectively. In the future, motorized route 

proliferation would continue at an unknown rate because unmanaged cross country travel would continue.

Sensitive Species Determinations 

The Tahoe NF Biological Evaluation for Birds, Mammals, Amphibians, Reptiles, Fish, and Invertebrates 

is incorporated by reference in the Project Record. Based on the spotted owl analysis of effects, the 

Biological Evaluation for the Tahoe NF Travel Management EIS made a determination that 

implementation of all the actions alternatives may affect spotted owls, but are not likely to lead to a trend 

toward listing or a loss in population viability.

Although, some habitat fragmentation and edge effects would occur from the action alternatives, none 

of the action alternatives would likely cause enough fragmentation to be a concern to spotted owl 

population viability on the Tahoe NF when considering the combined effects of the alternatives and the 

additional activities occurring within the cumulative effects analysis area. Based on this information and 

the findings from U.S. Fish and Wildlife Service, the alternatives as proposed are not expected to result in 

a loss of viability or lead to a trend toward Federal listing for the California spotted. The alternatives 

would not likely affect Forest-wide spotted owl population trends. In addition, recent studies between off 

highway vehicles and spotted owls indicate that disturbance associated with off-highway vehicle do not 

affect reproductive success. However, the uncertainty of long term effects to spotted owls from increasing 

disturbance from motorized vehicle use poses an unknown risk. Under Alternative 1, cross country travel 

would continue on 50,712 PAC acres and 98,806 HRCA acres, which could cause long-term chronic 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

304 – Tahoe National Forest

effects to spotted owl from factors associated with motorized routes. In addition, uncontrolled motorized 

route proliferation over time may contribute to downward spotted owl population trends on the Tahoe NF.

MIS Summary

The California spotted owl was selected as an MIS for late-seral closed canopy coniferous forest (5M, 5D, 

6M, 6D within ponderosa pine, Sierran mixed conifer, white fir, and red fir) habitat in the Sierra Nevada. 

The Sierra Nevada Forests Bioregional MIS Report and the Tahoe NF Motorized Travel Management 

MIS Project-level Report are incorporated by reference.

Based on the MIS analysis conducted, Alternative 1 directly, indirectly, and cumulatively affects the 

greatest amount of late-seral closed canopy coniferous forest with a 200-meter Zone of Influence of 

existing unauthorized routes, which would continue without prohibiting cross country travel. Alternative 

1 reduces habitat effectiveness by 8% (13,435 acres out of 167,938 Tahoe NF habitat acres), with the 

potential to disturb, cause avoidance, and abandonment of California spotted owl, American marten, and 

northern flying squirrel. Considering the checkerboard pattern of land ownership within the Tahoe NF 

boundary, Alternative 1 could cause a downward trend in habitat effectiveness for these species. In 

addition, the cross country travel would continue and proliferate on 119,091 acres of late-seral closed 

canopy coniferous forest habitat.

Alternatives 2, 4, 5, and 6 would affect 1,679 acres of late-seral closed canopy coniferous forest 

habitat or 1% of Tahoe NF habitat within a 200-meter Zone of Influence of proposed motorized route 

additions. Alternatives 3 and 7 do not affect late-seral closed canopy coniferous forest habitat within a 

200-meter Zone of Influence of proposed motorized route additions to the NFTS. The Tahoe NF 

Motorized Travel Management Project action alternatives would not result in a direct or indirect change 

in the amount of late-seral closed canopy coniferous forest habitat affected by motorized routes for all the 

alternatives. Therefore, habitat effectiveness for these species would be maintained at current levels. 

For all the alternatives, the change in the class of vehicles would not directly, indirectly, or 

cumulatively affect late-seral closed canopy coniferous forest habitats or their habitat effectiveness. Wet 

weather seasonal restrictions on all native surfaced roads and motorized trails under Alternatives 4, 5, and 

6 would not likely affect late-seral closed canopy coniferous forest habitat effectiveness for the California 

spotted owl, American marten, and the northern flying squirrel, but slight localized reduced disturbance, 

avoidance, and abandonment may result. Finally, the prohibition of motorized cross country travel on 

119,091 acres of late-seral habitats would benefit these species over time, thereby preventing the 

continued cumulative increase in motorized route proliferation in the future.

Summary of Status and Trend at the Bioregional Scale. The Tahoe NF LRMP (as amended by the 

SNF MIS Amendment) requires bioregional-scale habitat and distribution population monitoring for the 

California spotted owl; hence, the late-seral closed canopy coniferous forest (ponderosa pine, Sierran 

mixed conifer, white fir, and red fir) habitat effects analysis for the Tahoe NF Motorized Travel 

Management Project must be informed by both habitat and distribution population monitoring data. The 

sections below summarize the habitat and distribution population status and trend data. This information 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 305

is drawn from the detailed information on habitat and population trends in the SNF Bioregional MIS 

Report (USDA Forest Service 2008), which is hereby incorporated by reference.

Habitat Status and Trend. There are currently 994,000 acres of late-seral closed canopy coniferous 

forest (ponderosa pine, Sierran mixed conifer, white fir, and red fir) habitat on NFS lands in the Sierra 

Nevada. The trend is slightly increasing (from 7% to 9% within the last decade on NFS lands).

Population Status and Trend California spotted owl has been monitored in California and 

throughout the Sierra Nevada through general surveys, monitoring of nests and territorial birds, and 

demography studies (Verner et al. 1992; USDA Forest Service 2001, 2004, 2006; USFWS 2006; Sierra 

Nevada Research Center 2007). Current data at the range wide, California, and Sierra Nevada scales 

indicate that, although there may be localized declines in population trend [e.g., localized decreases in 

“lambda” (estimated annual rate of population change)], the distribution of California spotted owl 

populations in the Sierra Nevada is stable.

Relationship of Project-Level Habitat Impacts to Bioregional-Scale Trends for the species. 

Based on the small proportion of late-seral closed canopy coniferous forest habitat that is directly, 

indirectly and cumulatively affected (0% to 1.4% of Sierra Nevada habitat) by the alternatives, the Tahoe 

NF Motorized Travel Management Project would not alter existing trend in the habitat, nor would it lead 

to a change is the distribution of California spotted owl across the Sierra Nevada bioregion.

Summary of Direct and Indirect, Impacts to Spotted Owls

Table 3.03-72 summarizes the alternatives for the direct and indirect effects to California spotted owl 

from cross country travel, motorized route additions to the NFTS, establishment of “Open Areas,”

changes to the NFTS (wet weather restrictions, changes in class of vehicles and reopened ML 1 roads), 

and Amendments to the Forest Plan.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

306 – Tahoe National Forest

Table 3.03-73. California Spotted Owl - Summary of Direct and Indirect Effects (PACs, HRCAs, and 0.25 mile radius of Activity Centers)

Alt 11 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Habitat Acres 

Where Cross 

Country 

Travel 

Prohibited

1⁄4 mile of Nests site/stand 0 18,535 18,535 18,535 18,535 18,535 18,535

PACs 0 50,712 50,712 50,712 50,712 50,712 50,712

HRCAs 0 98,806 98,806 98,806 98,806 98,806 98,806

Motorized Route Additions

Trend of Effect Negatively 

affects the 

greatest 

proportion of 

spotted owl 

habitat within 

PACs, within 

0.25 miles of 

activity 

centers, and 

HRCAs

4th most negative 

impacts to a very 

small proportion 

of spotted owl 

habitat within 

PACs, within 

0.25 miles of 

activity centers, 

and HRCAs

No Effect 6th most 

negative 

impacts to a 

very small 

proportion of 

spotted owl 

habitat within 

PACs, within 

0.25 miles of 

activity centers, 

and HRCAs

2nd most negative

impacts to a 

small proportion 

of spotted owl 

habitat within 

PACs and 

HRCAs. Sligh

3nd most negative 

impacts to a very 

small proportion 

of spotted owl 

habitat within 

PACs and 

HRCAs. At nest 

stand scale, has 

slightly greater 

impacts than Alts 

5 and 6.

5th most negative 

impacts to a very 

small proportion 

of spotted owl 

habitat within 

PACs, within 

0.25 miles of 

activity centers, 

and HRCAs

Nests site/stand (within 1⁄4 mile 

of Activity Center)

Miles 41.1 0.2 0 0 0.2 0.4 0.2

PACS ZOI 22% 0.6% 0% 0% 0.7% 0.7% 0.3%

Miles 98.1 1.8 0 0 2.2 2.0 1.6

HRCAs ZOI 22% 1.2% 0 0.5% 1.3% 1.2% 0.5%

Miles 281.7 13.3 0 6.2 14.8 11.0 7.6

Establishment of “Open Areas” No Effect No Effect No Effect No Effect No Effect No Effect No Effect
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 307

Alt 11 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Changes 

to NFTS

Wet Weather Restrictions No Effect No Effect No Effect Beneficial 

from reduced 

disturbance

Beneficial from 

reduced 

disturbance

Beneficial from 

reduced 

disturbance

No Effect

Change in Class of Vehicles No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Reopened 

ML 1 

Roads

Trend of Effect No Effect Negative, shares

3rd most impacts 

with Alt 7

No Effect Negative, 

shares 3nd most 

impacts with Alt 

7.

Negative, most 

impactive 

alternative

Negative, 2nd

most impacts 

Negative, shares 

3nd most impacts 

with Al t 2.

1⁄4 mi. of 

nests site

Miles 0 0 0 0 2.5 0 0

PACs ZOI 0% <1% 0% 0% 1% <1% <1%

Miles 0 0.9 0 0 6.1 1.3 0.9

HRCAs ZOI 0% <1% 0% <1% 1.5% 0% 0%

Miles 0.8 0 0.1 10.9 0 0

Overall Effects of Proposed Alternatives Negative effects 

primarily due to 

un-managed 

cross country 

travel where 

most threatens 

of disturbance 

and habitat 

fragmentation.

Benefits PACs, 

within 0.25 miles 

of activity 

centers, and 

HRCAs, where 

cross country 

travel is 

prohibited; 

although minor 

negative impacts 

from route 

additions and 

reopened ML 1 

roads; overall 

Reduces 

disturbance and 

habitat 

fragmentation.

Benefits PACs, 

within 0.25 

miles of activity 

centers, and 

HRCAs, where 

cross country 

travel is 

prohibited.

Reduces 

disturbance 

and habitat 

fragmentation.

Benefits PACs, 

within 0.25 

miles of activity 

centers, and 

HRCAs, where 

cross country 

travel is 

prohibited; 

although minor 

negative 

impacts from 

route additions 

and reopened 

ML 1 roads; 

overall reduces 

disturbance and 

habitat 

fragmentation..

Benefits PACs, 

within 0.25 miles 

of activity 

centers, and 

HRCAs, where 

cross country 

travel is 

prohibited; 

although minor 

negative impacts 

from route 

additions and 

reopened ML 1 

roads; overall 

Reduces 

disturbance and 

habitat 

fragmentation.

Benefits PACs, 

within 0.25 miles 

of activity 

centers, and 

HRCAs, where 

cross country 

travel is 

prohibited; 

although minor 

negative impacts 

from route 

additions and 

reopened ML 1 

roads; overall 

Reduces 

disturbance and 

habitat 

fragmentation.

Benefits PACs,

within 0.25 miles 

of activity 

centers, and 

HRCAs, where 

cross country 

travel is 

prohibited; 

although minor 

negative impacts 

from route 

additions and 

reopened ML 1 

roads; overall 

Reduces 

disturbance and 

habitat 

fragmentation.

1

Alternative 1 includes existing unauthorized routes that would continue with cross country travel, while all the action alternatives include proposed route additions.

2

Zone of Influence is 200 meters of motorized route additions and reopened ML 1 roads
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

308 – Tahoe National Forest

Compliance with the Forest Plan and Other Direction

The Tahoe NF LRMP, as amended by the SNFPA ROD (2004) provided management standards and 

guidelines for the California spotted owl as follows:

Evaluate proposals for new roads, trails, off highway vehicle routes, and recreational and other 

developments for their potential to disturb nest sites (Management Standard & Guideline 82). 

Alternatives under the Tahoe NF Travel Motorized Management Project were evaluated for their 

potential to disturb California spotted owl nest sites at two scales—(1) within spotted owl Protected 

Activity Centers (PACs) and (2) within a 0.25 mile radius of known nest sites or activity centers. Analysis 

of the alternatives indicates Alternative 1 disturbs nest sites the most from allowing cross country travel to 

continue on 50,712 PAC acres, affecting 22% of PAC acres within a 200-meter Zone of Influence of 

existing unauthorized routes. Compared to Alternative 1, the action alternatives all reduce overall effects 

to spotted owl PACs by prohibiting cross country travel, including 22% of PAC acres within a 200-meter 

Zone of Influence of existing unauthorized routes. Analysis of the alternatives within 0.25 mile of activity 

centers (i.e. nest sites) indicates a similar pattern as found for spotted owl PACs.

Northern Goshawk: Affected Environment

The northern goshawk is designated as a Forest Service Sensitive Species in Region 5. There are currently 

285,695 acres of suitable goshawk habitat on NFS lands within the Tahoe NF as defined by CWHR types 

4 M, 4D, 5M, 5D, and 6. Northern goshawk territories are managed on the Tahoe National Forest as 

Protected Activity Centers (PACs) as prescribed by the Sierra Nevada Forest Plan Amendment (2004). To 

date, the Tahoe National Forest has 97 known northern goshawk PACs.

Collection, habitat loss or fragmentation, disturbance at a specific site, and edge effects were 

described by Gaines et al. (2003) as being road and trail-associated factors that potentially affect the 

northern goshawk.

Collection: The Sierra Nevada Forest Plan Amendment (USDA Forest Service 2001) cited that 

northern goshawk were harassed and shot in areas where human recreation was concentrated. 

Additionally, the Forest Service identified illegal harvest may pose a risk to local populations in certain 

areas. Both illegal and legal harvest has the potential to affect local individual territories that receive 

repeated visits and harvesting. No specific incidence of illegal goshawk harvest is known from the Tahoe 

NF area, though local falconers have knowledge of specific goshawk territories on the Forest which are 

likely getting repeated visitation and harvesting. 

Disturbance at a Specific Site: Human disturbance has the potential to cause goshawk to abandon 

nesting during the nesting and post fledging period (February 15 through September 15). Goshawk 

initiate breeding when the ground is still covered in snow. Sometimes nests are constructed along roads 

and trails. Additionally, roads and trails provide flight access for goshawk. When the snow melts, these 

sites can potentially be areas of conflict as these roads and trails are used by people. Joslin and Youmans 

(1999) recommend maintaining low road densities to minimize disturbance to goshawk. Grubb et al. 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 309

(1998) reported that vehicle traffic from roads did not elicit any discernable behavioral response from 

goshawk at distances exceeding 400 meters (0.25 miles) from nests. 

Habitat Loss and Fragmentation and Edge Effects: a network of roads and motorized trails can 

fragment goshawk habitat by reducing canopy closure (Beier and Drennan 1997, Daw and DeStefano 

2001) and by reducing forest interior patch size. However, how habitat fragmentation from roads and 

trails affects goshawk habitat suitability is not well understood. Generally, wider roads that receive higher 

volumes of traffic result in greater habitat fragmentation. Native surfaced roads and trails probably do not 

pose as much a risk to habitat fragmentation compared to smooth surfaced roads. For obvious reasons, 

state and federal highways create the greatest habitat fragmentation due to the width of the road and 

associated edge effects.

Northern Goshawk: Environmental Consequences

Indicators used to Measure Effects

Disturbance to Nesting Northern Goshawk

The direct and indirect effects to nesting northern goshawk may be measured by the amount of 

disturbance that may be generated from noise or other motorized trail and road associated factors by the 

following indicators:

Cross Country Travel: The acres of cross country travel within northern goshawk Protected Activity 

Centers (PACs) and within 0.25 mile radius of goshawk nest sites or nest stands are determined for each 

of the alternatives.

Additions to the NFTS and Changes to the NFTS--Reopened ML 1 Roads: Motorized route 

additions to the NFTS and Changes to the NFTS from Reopened ML 1 Roads are analyzed to determine 

how they would impact northern goshawk “disturbance to a specific site. Disturbance to goshawk PACs 

and nest sites is analyzed for the alternatives at two scales-- within 0.25 miles of spotted owl Activity 

Centers (nest sites or nest groves), within PACs.

• Nest or Nest Stand (Within a 0.25 miles radius of spotted owl Activity Centers): Activity 

Centers are known nest sites or suspected nest stands. Nest abandonment and failure can result 

from excessive noise disturbance that may be associated with use of motorized routes. The miles 

of proposed motorized route additions and the miles of reopened ML 1 roads within a 0.25 mile 

radius of goshawk Activity Centers are compared by each of the alternatives to display the 

potential impact to goshawk nesting sites from noise disturbance and other factors associated with 

motorized use.

• Protected Activity Centers (PACs): Goshawk PACs are delineated surrounding all known and 

newly discovered nesting territories on NFS lands on the Tahoe NF . PACs are designated to 

include the latest documented nest site and location of alternate nests (SNFPA 2004). PACs 

encompass the best available 200 acres of forested habitat which include (1) 2 or more canopy 

layers, (2) trees in the dominant and co-dominant crown classes averaging 24 inches diameter at 

breast height or greater; (3) in westside conifer and eastside mixed conifer forest types, stands 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

310 – Tahoe National Forest

have at least 70 percent tree canopy cover; and (4) in eastside pine forest types, stands have at 

least 60 percent tree canopy cover.

• The miles of proposed additions to the NFTS and the miles of reopened ML 1 roads within 

goshawk PACs are compared to determine how the various alternatives have the potential impact 

nesting goshawk from noise disturbance and other factors associated with motorized use.

Northern Goshawk: Direct and Indirect Effects 

Disturbance to Nesting Northern Goshawk

Cross Country Travel

Nest Site or Nest Stand (Within 0.25 Mile of Goshawk Activity Centers)

Alternative 1 would significantly add to adverse cumulative effects within goshawk PACs and to nest 

sites/groves, and would potentially disturb nesting goshawk habitat since on cross country would continue 

on 10,384 goshawk PAC acres because unmanaged cross country motorized travel would continue and 

proliferate into the future. Nesting goshawk would benefit from implementation of the action alternatives 

by prohibiting cross country travel on at least 10,384 PAC acres, which would greatly reduce habitat 

fragmentation and disturbance to nesting goshawk from motorized use.

Protected Activity Centers

Alternative 1 would significantly add to adverse cumulative effects within goshawk PACs and to nest 

sites/groves, and would potentially disturb nesting goshawk habitat since on cross country would continue 

on 20,036 goshawk PAC acres because unmanaged cross country motorized travel would continue and 

proliferate into the future. Alternative 1 would limit cross country travel on only 644 acres that are 

currently closed to motorized use under the existing LMP standards and guidelines. Whereas all the action 

alternatives would benefit goshawk within goshawk PACs by prohibiting cross country travel on an 

additional 20,036 acres, which would greatly reduce habitat fragmentation and disturbance to nesting 

goshawk from motorized use. 

Additions to the NFTS and Reopened ML 1 Roads

Nest Site or Nest Stand (Within 0.25 Mile of Goshawk Activity Centers)

Table 3.03-74 displays the potential effects of the proposed motorized additions and reopened ML 1 roads

on nesting goshawk within a 0.25 mile radius circle of goshawk Activity Centers (nest site or nest stand). 

Alternative 1 would pose the greatest risk from noise disturbance to nesting goshawk by allowing 

continued cross country motorized travel, including motorized use on nearly 25 miles of existing 

unauthorized routes within 0.25 miles of goshawk activity centers. Alternative 1 would not propose to 

reopen any ML 1 roads, and therefore no effects to nesting goshawk would occur.

All the action alternatives would reduce the amount of disturbance to nesting goshawk by at least 24 

miles from the either the addition of motorized routes and reopened ML 1 roads. The action alternatives 

affect from 0 to 0.3 miles of motorized route additions (Alternative 3 adds none, Alternatives 5 and 6 add

0.3 miles). Reopened ML 1 roads would only affect nesting goshawk under alternatives 2, 4, 5, and 6, 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 311

where less than 0.1 to 0.8 miles would be added. Of these alternatives Alternative 5 would reopen the 

most miles (0.8 miles) and Alternative 4 would reopen the least miles (less than 0.1).

Table 3.03-74. Miles of Proposed Motorized Route Additions and Reopened ML 1 Roads within 0.25 Mile 

Radius Circle of Northern Goshawk Activity Center (Nest Site or Nest Stand)

Miles Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Motorized Route additions to the NFTS 24.8 0.2 0 <0.1 0.3 0.3 0.2

Reopened ML 1 Roads 0 0.4 0 0 0.4 0.8 0

Total 24.8 0.6 0 <0.1 0.7 1.1 0.2

*Alternative 1 includes existing unauthorized routes associated with cross country travel, whereas all the action alternatives include 

route additions or reopened ML 1 roads.

Protected Activity Centers

The miles of proposed motorized routes to be added to the NFTS are compared to determine how the 

various alternatives have the potential to impact breeding Northern goshawks from noise disturbance and 

other factors associated with motorized use. 

Table 3.03-75 displays the miles of motorized route additions to the NFTS within goshawk PACs by 

route identification number, and miles of route additions for the alternatives. It also displays the number 

and percentage of PACs affected by proposed motorized route additions to the NFTS for each alternative. 

There are a total of 97 goshawk PACs designated on the Tahoe NF. 

Alternative 1 contributes significantly to direct and indirect effects to breeding goshawk, where cross 

country motorized travel would continue, including motorized use of over 42 miles of existing motorized 

unauthorized routes, where 68% of goshawk PACs (66 PACs) on the Tahoe NF would be subjected to 

disturbance from continued cross country travel. 

All the action alternatives would reduce the miles of motorized routes within goshawk PACs by at 

least 40 miles compared to Alternative 1. Alternatives 2, 5, 6, and 7 would add approximately 1 motorized 

route mile affecting between 2 and 5 goshawk PACs, ranging from less than 0.01 mile to about 1⁄2 mile in 

length. Alternatives 3 and 4 do not propose any motorized routes to be added to the NFTS within 

goshawk PACs, and therefore, would not cause direct or indirect effects to nesting goshawk. 

Five goshawk PACs (Frazier Creek, Lacy Creek, Wornmill, and Castle Valley) are intersected by 

proposed route additions which are short spurs which provide access to dispersed recreation sites. The 

amount of disturbance resulting from routes accessing dispersed recreation sites depends on the type and 

amount of dispersed recreation that occurs in association with these routes. The following summary 

briefly describes how each goshawk PAC is affected by motorized route additions for Alternatives 2, 5, 6, 

and 7.

Frazier Creek PAC (R05F17D54T07): The Frazier Creek PAC would be affected by the addition of 

short route (.01 mi) to access a dispersed recreation site under Alternative 6.

Omega PAC (R05F17D55T18): The Omega PAC would be affected by the addition of route H29-11 

totaling 0.1 mile under Alternative 5.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

312 – Tahoe National Forest

Lacy Creek PAC (R05F17D56T08): The Lacy Creek PAC would be affected by the addition of a 

route to access a dispersed recreation site under Alternative 6.

Wornmill PAC (R05F17D57T11): The Wornmill PAC would be affected by the addition of route 

TKN-J9 (0.3 mi) under alternatives 2, 5, 6, and 7. In addition, 2-3 routes accessing dispersed recreation 

sites are proposed under Alternatives 2, 5, and 6. Alternative 6 would result in 1 additional route to a 

dispersed site compared to Alternatives 2 and 5. However, Alternative 5 also proposes to add a very short 

segment (N270-8-5) totaling less than 0.01 mile. In sum, the differences between alternatives 2, 5, and 6 

would be very little, if any at all. Of the four alternatives affecting the Wornmill PAC, Alternative 7 would 

result in the least disturbance to nesting goshawk for the Wornmill PAC, since no routes accessing 

dispersed recreation sites are proposed under this alternative.

Castle Valley PAC (R05F17D57T15): The Castle Valley PAC would be affected by the addition of 

TKN-J5 under alternatives 2, 5, 6, and 7. TKN-J5 totals about 0.5 miles and is coincidental with the 

southern boundary of the Castle Valley PAC. Based on the vicinity of TKN-J5, it is likely that this route 

would have lesser disturbance impacts to nesting goshawk than if the route were to dissect the PAC area.

Alternative 6 also proposes to add 5 short routes totaling less than 0.1 mile that come off of TJN-J5.

These dispersed recreation assess routes could result in increased disturbance to nesting goshawk within 

the Castle Valley PAC.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 313

Table 3.03-75. Northern Goshawk PACs - Miles of Motorized Route Additions by PAC ID and Route ID

Goshawk PAC ID Territory Name Route ID Alt. 1 Alt. 2 Alt. 3 Alt. 4 Alt. 5 Alt. 6 Alt. 7

Numerous PACs Numerous Unauthorized routes 42.3 0 0 0 0 0 0

R05F17D54T07 Frazier Creek

D_44_c

(route to dispersed site)

0 0 0 0 0 0.01 0

R05F17D55T18 Omega H29-11 0 0 0 0 0.1 0 0

R05F17D56T08 Lacy Creek

D_86-40-30

(route to dispersed site)

0 0 0 0 0 0.02 0

R05F17D57T11 Wornmill

D_72

(route to dispersed site)

0 0 0 0 0 0.04 0

R05F17D57T11 Wornmill

D_72_a & b 

(routes to dispersed site)

0 0.04 0 0 0.04 0.04 0

R05F17D57T11 Wornmill N270-8-5 0 0 0 0 <0.01 0 0

R05F17D57T11 Wornmill TKN-J9 0 0.30 0 0 0.30 0.30 0.30

R05F17D57T15 Castle Valley TKN-J5 0 0.52 0 0 0.52 0.52 0.52

R05F17D57T15 Castle Valley

D_TKN-J5_a, b, c, d, e

(routes to dispersed site)

0 0 0 0 0 0.05 0

Number PACs Intersected 66 2 0 0 5 5 2

Percentage PACs Affected (TNF PACs = 97) 68% 2% 0% 0 5% 5% 2%

Total Miles 42.3 0.9 0.0 0.0 0.9 1.0 0.8

* Motorized Route Additions - Alternative 1 includes existing unauthorized routes associated with continued cross country travel
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

314 – Tahoe National Forest

Reopened ML 1 Roads

Table 3.03-76 displays how the alternatives are affected by reopened ML 1 roads. Only alternatives 2, 5, 

and 6 propose to reopen ML 1 roads, potentially affecting 1 to 2 goshawk PACs. The remaining 

alternatives do not propose to reopen ML 1 roads, and therefore would not affect any goshawk PAC.

Alternative 6 would affect two goshawk PACs (Tad Pole PAC and Perazzo Meadow PAC) for a total of 

about 0.7 miles where nesting goshawk could be disturbed from motorized activities associated with 

reopened ML 1 roads (ARM-3 and SV-005). Following Alternative 6, Alternative 5 would reopen a total 

of 0.4 miles of ML 1 roads potentially where nesting goshawk could be disturbed from motorized use 

within the Perazzo Meadow PAC and the Robinson Flat PAC. Of the three alternatives potentially 

affecting PACs from reopened ML 1 roads, Alternative 2 would affect the least, where only the Perazzo 

Meadow PAC would be affected by reopening 0.3 miles of ML 1 road.

Table 3.03-76. Miles of Reopened ML 1 Roads by Northern Goshawk PAC and Route ID 

Goshawk PAC ID Territory Name Route ID Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

R05F17D54T14 Tad Pole ARM-13 0 0 0 0 0 0.35 0

R05F17D54T15 Robinson Flat H88-44 0 0 0 0 0.10 0 0

R05F17D56T04 Perazzo Meadow SV-005 0 0.31 0 0 0.31 0.31 0

Number PACs Intersected 0 1 0 0 2 2 0

Percentage PACs Affected (TNF PACs = 97) 0 1% 0% 0% 2% 2% 0%

Total Miles 0 0.31 0 0 0.41 0.66 0

Effects to Individual Northern Goshawk PACs from Route Additions and Reopened ML 1 

Roads. The routes proposed to be added to the NFTS and the reopened ML 1 roads (converted from 

closed to open) contribute a certain amount of disturbance to the activity center on which each PAC is 

based. Disturbance could result in flushing from nests, roosts, or perches, in alarm responses, and in 

increased stress hormone levels in individual goshawks. In the absence of further research, it is assumed 

that motorized use along all routes within 400 meters (0.25 mile) of activity centers would result in some 

disturbance to nesting goshawk. Based on that assumption, approximately 1-2% of activity centers would 

receive some disturbance from routes added to the NFTS and/or routes that would be reopened. Without 

further research, this analysis assumes that effects within 60 meters (approximately 60 meters) of an 

activity center will result in negative effects to reproduction over the short term. Therefore, if all the 

routes proposed to be added to the NFTS or proposed to be reopened are further than 400 meters from the

activity center on which a given PAC is based, it is assumed that the routes under this alternative in that 

PAC would contribute a low level of disturbance to the goshawks at that activity center. If any of the 

routes proposed to be added or reopened are between 60 and 400 meters from the activity center on which 

the PAC is based, it is generally assumed that the routes in that PAC would contribute a moderate level of 

disturbance to the owls at that activity center. Within certain PACs meeting that criterion, the contribution 

to disturbance was rated as low for the reasons given below. If any of the routes proposed to be added or 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 315

reopened are within 60 meters of the activity center, it is assumed that the routes under this alternative in 

that PAC would contribute a high level of disturbance to the owls at that activity center.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

316 – Tahoe National Forest

For each of the proposed route additions and reopened ML 1 roads, the relative “LEVEL OF CONTRIBUTION TO DISTURBANCE” to each

PACs “activity center” and supporting rationale is shown in Table 3.03-77.

Table 3.03-77 Level of Contribution to Disturbance to Northern Goshawk by Specific PAC for Route Additions and Reopened ML 1 Roads

PAC 

Number

Territory 

Name

Route ID Route 

Addition

Reopened 

ML 1 Rd

Length

(miles)

Alternatives Level of 

Contribution 

to 

Disturbance

Rationale

D54T07 Frazier Creek D_44_c X 0.01 Alt 6 Low to none Proposed route is short spur <.01 mi, off of 

existing system route, located >400 meters from

nest site. Route located at very extreme northwest

boundary of PAC, should not add to disturbance.

D54T14 Tad Pole ARM-13 X 0.35 Alt 6 Low Proposed route is 0.3 mi (>400 meters) from 

known nest site.

D54T15 Robinson Flat H88-44 X 0.10 Alt 5 Low Proposed route is 0.4 mi (>400 meters) from 

known nest site, route is near northern edge of 

PAC.

D55T18 Omega H29-11 X 0.1 Alt 5 Moderate Short route segment within PAC located 0.05 mi 

(>60 meters, <400 meters) from known nest site.

D56T04 Perazzo SV-005 X 0.6 Alts 2, 5, 6 Moderate Reopened route located 0.05 mi (>60 meters and 

<400 meters) from most recent known nest site.

D56T08 Lacy Creek D_86-40-30 X 0.02 Alt 6 Low Short route segment comes off of existing system 

road, route located at 400 meters (0.25 mi) from 

known nest site.

D57T11 Wornmill D_72 X 0.04 Alt 6 Low Short route comes off of existing system road, 

route located 0.7 mi (>400 meters) from nest site.

D57T11 Wornmill D_72_a & b X 0.04 Alt 6 Low Two short routes at eastern edge of boundary 

come off of existing system road, routes located 

0.9 mi (>400 meters) from known nest site.

D57T11 Wornmill N270-8-5 X <0.01 Alt 5 Low Very short route comes off of existing system 

road, located 0.3 mi (> 400 meters) from known 

nest site.

D57T11 Wornmill TKN-J9 X 0.30 Alts 2, 5, 6, 7 Moderate Proposed route is along existing powerline, 

located within 0.15 mi (< 400 meters) of 1 of 3 

alternate nest sites.

D57T15 Castle Valley TKN-J5 X 0.52 Alts 2, 5, 6, 7 Low Proposed route borders southern edge of PAC, 

route located 0.3 mi (>400 meters) from known 

nest site.

D57T15 Castle Valley D_TKN-J5_a, 

b, c, d, e

X 0.05 Alt 6 Low Short route segments comes off of proposed route 

TKN-J5 and located >400 meters from known nest 

site.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 317

Summary of Individual PAC Analysis

Table 3.03-78 summarizes the potential risk of increased disturbance to goshawk activity centers within 

PACs out of a total of 97 goshawk PACs, as a result of motorized route additions and reopened ML 1 

roads. Alternatives 3 and 4 would not increase disturbance to goshawk within any PAC, since no routes or 

reopening of ML 1 road would be proposed. Overall, Alternative 6 would result in the greatest number of 

goshawk PACs (9 of 97 PACs or 9%) could be affected either by a low or moderate risk of increased 

disturbance from activities associated with motorized route additions or reopened roads through 

temporary displacement, nest failure, or territory abandonment. Alternatives 7, 2, 5, and 6 would 

potentially increase disturbance to goshawk activity centers within PACs, in increasing order, ranging 

from 2% to 9%. None of the alternatives would add routes or reopen ML 1 roads that would result in a 

“high” risk of increased disturbance where a route would be added or reopened ML 1 road would occur 

within 60 meters (200 feet) of a spotted owl activity center. The remaining action alternatives would 

result in either a low or moderate risk of increased disturbance from the addition of routes or reopening 

ML 1 roads. Alternative 5 would result in the most number of PACs (3 of 97 or 3%) potentially affected 

by a moderate level of increased disturbance, followed by Alternatives 2 and 6 (2 of 97 PACs or <2%, and

Alternative 7 would result in the least amount of moderately increased disturbance to PACs (1of 97 PACs 

or 1%). Alternative 6 would result in the greatest number of PACs with a low risk of increased 

disturbance (7 of 97 PACs or 75), followed by alternatives 5, 2, and 7 in decreasing order (Table 3.03-78).
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318 – Tahoe National Forest

Table 3.03-78. Northern goshawk: summary of risk of increased disturbance to Activity Centers within PACs

Alt 1 Alt 2 Alt 3, 4 Alt 5 Alt 6 Alt 7

Risk of increased 

disturbance 

effects

Rationale #

PACs

%

PACs

#

PACs

%

PACs

#

PACs

%

PACs

#

PACs

%

PACs

#

PACs

%

PACs

#

PACs

%

PACs

HIGH Route added or reopened ML 1 

road within 60 meters (200 feet) of 

activity center

0 0% 0 0% 0 0% 0 0% 0 0% 0 0%

MODERATE Routes added or reopened ML 1 

roads occurring less than 400 

meters (1/4 mi) and more than 200 

feet from activity center, and no 

intervening topography

0 0% 2 2% 0 0% 3 3% 2 2% 1 1%

LOW All routes added or reopened ML 1 

roads greater than 400 meters from 

activity center.

0 0% 2 2% 0 0 3 3% 7 7% 1 1%

HIGH PACs where cross country travel 

continued

96 99% 0 0 0 0 0 0 0 0 0 0

DECREASE PACs where cross country travel 

prohibited, including on 

unauthorized routes 

0 0% 96 99% 96 99% 96 99% 96 99% 96 99%

Total PACs in which routes are added and/or being 

converted from closed ML 1 roads to open

0 0% 4 4% 0 0% 6 6% 9 9% 2 2%

Total PACs where cross country travel continued, 

including on unauthorized routes

96 99% 0 0% 0 0% 0 0% 0 0% 0 0%

Total PACs where cross country travel would be 

prohibited, including on unauthorized routes

0 0% 96 99% 96 99% 96 99% 96 99% 96 99%
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 319

Summary of Direct and Indirect Impacts to Northern Goshawk 

When considering all the direct and indirect impacts to the northern goshawk within PACs and within 

0.25 miles of activity centers (nest sites/nest stands), Table 3.03-79 summarizes the overall net effect to 

the northern goshawk from the proposed actions from cross country travel, motorized route additions to 

the NFTS, establishment of “Open Areas,” changes to the NFTS (change of season of use, change in class 

of vehicles, reopened ML 1 roads), and amendments to Forest Plan.
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320 – Tahoe National Forest

Table 3.03-79. Northern Goshawk - Summary of Overall Net Direct and Indirect Effects

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres Cross 

Country 

Travel 

Prohibited

0.25 mile radius of 

Activity Center

0 10,384 acres 10,384 acres 10,384 acres 10,384 acres 10,384 acres 10,384 acres

PACs 0 20,036 acres 20,036 acres 20,036 acres 20,036 acres 20,036 acres 20,036 acres

Motorized Route Additions

Trend of Effect Negative, most 

impactive

alternative

Slight Negative, -

shares 3rd most 

impacts with Alt 

7

No Effect No Effect Slight negative,

shares 2nd most 

impacts with Alt 

6. 

Slight Negative, -

shares 2nd most 

impacts with Alt 

5.

Slight Negative, 

- shares 3rd most 

impacts with Alt 

2.

Within 0.25 mile radius of 

Activity Center (Miles)

24.8 0.2 0 0 0.3 0.3 0.2

PACs (Miles) 42.3 0.9 0 0 1.0 1.0 0.8

Percentage of PACs Affected 68% 2% 0% 0% 7% 6% 2%

Establishment of “Open Areas” No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Changes 

to NFTS

Wet Weather 

Restrictions

No Effect No Effect No Effect Beneficial from 

reduced 

disturbance

Beneficial from 

reduced 

disturbance

Beneficial from 

reduced 

disturbance

No Effect

Change in Class of 

Vehicles

No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Reopened 

ML 1 

Roads in 

PACs

Trend of 

effect

No Effect 3rd most 

impactive 

alternative

No Effect No Effect 2nd most 

impactive 

alternative

Most impactive 

alternative

No Effect

Miles 0 0.3 0 0 0.4 0.7 0

% PACs 

Affected

0 1% 0% 0% 2% 2% 0

Amendments to Forest Plan No Effect No Effect No Effect No Effect No Effect No Effect No Effect
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 321

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Overall Net Effect of Proposed 

Actions

Most impactive 

alternative. 

Increases 

disturbance and 

habitat 

fragmentation 

primarily from 

continued cross 

country travel

within 20,036 

PAC acres on 42 

miles of 

unauthorized 

routes.

4th most 

impactive 

alternative from 

the addition of 

routes and 

reopened ML 1 

roads totalling 

1.2 miles in 

PACs

Benefits 

goshawk from 

the prohibition of 

cross country 

travel, and 

reduces 

disturbance and 

habitat 

fragmentation 

within 20,036 

PAC acres..

Shares least 

impacts with 

Alternative 4 (no 

routes added or 

reopened).

Benefits 

goshawk from 

the prohibition of 

cross country 

travel, and 

reduces 

disturbance and 

habitat 

fragmentation 

within 20,036 

PAC acres.

Shares least 

impacts with 

Alternative 3. (no 

routes added or 

reopened).

Benefits 

goshawk from 

the prohibition of 

cross country 

travel, and 

reduces 

disturbance and 

habitat 

fragmentation 

within 20,036 

PAC acres..

3rd most 

impactive 

alternative from 

the addition of 

routes and 

reopened ML 1 

roads totalling 

1.4 miles in 

PACs.

Benefits 

goshawk from 

the prohibition of 

cross country 

travel, and 

reduces 

disturbance and 

habitat 

fragmentation 

within 20,036 

PAC acres.

2nd most 

impactive 

alternative from 

the addition of 

motrized routes 

and ML 1 roads, 

totalling 1.7 

miles in PACs.

Benefits 

goshawk from 

the prohibition of 

cross country 

travel, and 

reduces 

disturbance and 

habitat 

fragmentation 

within 20,036 

PAC acres..

5th most 

impactive 

alternative from 

the addition of 

routes totalling 

0.8 miles in 

PACs.

Benefits 

goshawk from 

the prohibition of 

cross country 

travel, and 

reduces 

disturbance and 

habitat 

fragmentation 

within 20,036 

PAC acres.

* Alternative 1 includes existing unauthorized routes that would continue with cross country travel, while all the action alternatives include proposed route additions.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

322 – Tahoe National Forest

Cumulative Effects to Nesting Goshawk

Cumulative Effects Boundary (space and time)

The cumulative effects geographic boundary for nesting goshawks includes all goshawk Protected 

Activity Centers and their associated Activity Centers (nest site or nest stand) within the boundary of the 

Tahoe NF. This is an appropriate scale for determining cumulative effects to the goshawk, since the Tahoe 

NF boundary is sufficiently large which includes 97 goshawk territories and their home range. In addition, 

the Tahoe NF boundary encompasses an array of goshawk habitat conditions from low elevation to high 

elevation, including several vegetation types including westside mixed conifer, ponderosa pine, true fir 

(red fir and white fir), eastside mixed conifer, pure eastside pine, lodgepole pine, and subalpine conifer. 

The cumulative effects timeframe is the same as other species - 20 years out into the future and 

approximately 20 years or more into the past. In addition, cumulative effects of all past actions are 

incorporated into the existing condition (see discussion of cumulative effects).

Assessing Cumulative Effects

Cumulative effects to nesting goshawk are assessed by determining the sum total miles of all motorized 

routes (proposed and existing) and non-motorized routes on the Tahoe NF including NFS lands and nonNFS lands (private) within goshawk PACs and within 0.25 mile radius of goshawk Activity Centers. For 

each alternative, cumulative effects are calculated by adding the total miles of proposed motorized routes 

(direct and indirect impacts) with existing motorized routes (NFS lands and non-NFS lands) and nonmotorized routes. Although non-motorized routes may have lesser impacts to goshawk compared to 

motorized routes, non-motorized routes are included in this analysis because human disturbance 

potentially may pose some level of disturbance to nesting goshawk depending on the level and duration of 

use during the breeding season. Non-motorized routes associated with high use non-motorized trails, such 

as the Pacific Crest Trail, may have considerable impacts to goshawk if nest sites are located nearby. 

Goshawks are known to exhibit territorial behavior, and have been known to dive bomb hikers during 

critical breeding periods.

Cross Country Travel

Existing motor vehicle cross country travel is currently banned on 644 goshawk PAC acres for all the 

alternatives. If Alternative 1 were implemented, cross country travel would only be prohibited on these 

644 acres. For all the action alternatives, the prohibition of cross country travel would benefit goshawk on 

an additional 20,036 PAC acres, where disturbance, avoidance, and abandonment would be reduced.

Whereas, Alternative 1 would continue cross country travel within 20,036 PAC acres, including on 

existing unauthorized routes. The ban of cross country travel on unauthorized routes would benefit 

goshawk because motorized use would no longer occur on these routes, since disturbance associated with 

these routes would be eliminated.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 323

Disturbance to Nesting Northern Goshawk

Protected Activity Centers

Considering the cumulative effects of all motorized and non-motorized routes on both NFS lands and 

non-NFS lands, indicates Alternative 1 would result in the most cumulative miles of routes (120 miles) 

within goshawk PACs on the Tahoe NF, and therefore poses the greatest overall potential risk and 

cumulative impacts to nesting goshawk on the Tahoe NF (Table 3.03-80) (Figure 3.03-6), where 

disturbance to nesting goshawk could result nesting failure and abandonment. All the action alternatives 

have similar cumulative route miles within PACs ranging from about 78 miles (Alternatives 3 and 4) to 

about 79 miles (remaining alternatives). Therefore, all the action alternatives would cumulatively benefit 

northern goshawk nesting where noise and other disturbance associated with motorized and nonmotorized use would be reduced by at least 40 miles. Individual goshawk PACs would receive cumulative 

adverse effects of noise and disturbance from the direct and indirect impacts of motorized route additions 

to the NFTS and reopened ML 1 roads, however, overall cumulative effects to goshawk Forest-wide 

would be significantly beneficial.

Table 3.03-80. Cumulative Miles of All Routes within Tahoe NF Goshawk PACs

Miles Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Direct and Indirect effects of proposed alternatives

Motorized route additions to NFTS* (negative impact) 42.3 0.9 0 0 1.0 1.0 0.8

Reopened ML 1 Roads 0 0.3 0 0 0.4 0.7 0

Unauthorized routes, where cross country travel would be prohibited 

(positive impact)

0 41.2 42.3 42.3 41.0 40.7 41.5

Cumulative effects of past, present, and proposed actions

Existing motorized routes - NFS lands (negative impact) 69.6 69.6 69.6 69.6 69.6 69.6 69.6

Existing motorized routes on private land - non-NFS lands (negative 

impact)

0.4 0.4 0.4 0.4 0.4 0.4 0.4

Existing non-motorized routes (negative impact) 7.7 7.7 7.7 7.7 7.7 7.7 7.7

Decommissioned routes (positive impact) 7.2 7.2 7.2 7.2 7.2 7.2 7.2

Closed Roads (ML1 roads, closed by previous NEPA, but not

implemented) (positive)

1.5 1.5 1.5 1.5 1.5 1.5 1.5

Total Cumulative Effects

Total Cumulative Impact = Sum Total of Negative Impacts both 

positive and negative

120.0 78.9 77.7 77.7 79.1 79.4 78.5

*Motorized route additions - Alternative 1 includes existing unauthorized motorized routes associated with continued cross country 

travel.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

324 – Tahoe National Forest

Figure 3.03-6. Cumulative Route Miles in Goshawk PACs

0.25 mile Radius Circle of Activity Centers (Nest Site or Nest Stand)

When analyzing the cumulative effects within the 0.25 mile radius circle of goshawk activity centers (nest 

site or nest stand), a similar theme emerges as compared to the cumulative effects of the proposed 

alternatives within PACs. Alternative 1 has the most cumulative route miles (74 miles) (Table 3.03-81)

(Figure 3.03-7). The remaining action alternatives would reduce the cumulative miles to around 50 miles 

compared to Alternative 1. The actual miles of motorized routes additions that would potentially affect

goshawk nest sites or nest groves, are very low (approximately range 0 to ~1 mile) across all goshawk 

territories on the Tahoe NF. Therefore, it can be concluded that implementing the alternatives would have 

very little additional cumulative impact to nesting goshawks on the Tahoe compared to Alternative 1. 

Alternative 1 clearly poses the greatest cumulative risk to nesting goshawk, with continued cross country

motorized travel on 10,384 acres, including continued use on approximately 25 miles of existing 

unauthorized routes within 0.25 mile of goshawk activity centers. Of the action alternatives, Alternative 6 

has the greatest cumulative motorized and non-motorized route miles (50.4 mi) and alternatives 3 and 4 

would share the least cumulative motorized and non-motorized route miles (49.3 mi).

Northern Goshawk 

Protect Activity Centers 

Cumulative Miles

0

20

40

60

80

100

120

140

1 2 3 4 5 6 7

Alternatives

Miles

Cumulative Miles
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 325

Table 3.03-81. Miles of All Routes within 0.25 mile of Tahoe NF Goshawk Activity Centers (nest site or nest 

stand) 

Miles Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Direct and Indirect effects of proposed alternatives

Motorized route additions to NFTS (negative impact)* 24.8 0.24 0 0.01 0.33 0.26 0.23

Reopened ML 1 roads (negative impact) 0 0.4 0 0 0.4 0.8 0

Unauthorized motorized routes prohibited to cross country 

travel (positive impact)

0 24.0 24.7 24.7 24.0 23.7 24.5

Cumulative effects of past, present, and proposed actions

Existing motorized routes - NFS lands (negative impact) 41.1 41.1 41.1 41.1 41.1 41.1 41.1

Existing motorized routes on private land - non-NFS lands 

(negative impact)

5.0 5.0 5.0 5.0 5.0 5.0 5.0

Existing non-motorized routes (negative impact) 3.2 3.2 3.2 3.2 3.2 3.2 3.2

Decommissioned routes (positive impact) 2.0 2.0 2.0 2.0 2.0 2.0 2.0

Roads Closed with previous NEPA decision, pending 

implementation (positive impact)

1.2 1.2 1.2 1.2 1.2 1.2 1.2

Total Cumulative Effects

Net Cumulative Impact = Sum Total of Negative Impacts minus positive impacts

Miles of routes 74.1 49.8 49.3 49.3 50.0 50.4 49.5

*Motorized route additions - Alternative 1 includes existing unauthorized motorized routes associated with continued cross country 

travel.

Figure 3.03-7. Cumulative Miles within 0.25 miles of Goshawk Activity Centers (Nest Site/Nest Stand)

Effects to Fragmentation and Edge Effects within Northern Goshawk Protected Activity Centers

Habitat fragmentation and edge effects were described for old forest coniferous associated species within 

old forest CWHR conifer types (4M, 4D, 5M, 5D, and 6) and within Old Forest Emphasis Areas (OFEAs) 

Northern Goshawk

Cumulative Miles 

Within 0.25 miles of Activity Centers

0

10

20

30

40

50

60

70

80

1 2 3 4 5 6 7

Alternatives

Miles

Cumulative Miles
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

326 – Tahoe National Forest

under the section “Effects Common to All Late-seral Coniferous Associated Species.” Those analyses 

provided a forest-wide view of how the alternatives affect spotted owl habitat fragmentation within lateseral coniferous forest habitats and OFEAs. This section provides a focused analysis of goshawk habitat

fragmentation and edge effects (including noise disturbance) from motorized routes at the site-specific 

goshawk PAC scale, where known goshawk nest territories are located. 

Indicators used to Measure Effects 

Zone of Influence within PACs to assess potential habitat fragmentation and edge effects: In addition 

to determining the habitat fragmentation potential from zones of influence within suitable goshawk 

habitat within CWHR types 4M, 4D, 5M, 5D, and 6 (See effects to late-seral coniferous forest habitats in 

effects common to all late-seral coniferous forest associated species), zones of influence were determined 

within goshawk PACs at 400 meters (0.25 mile) of proposed motorized routes added to the NFTS and 

reopened ML 1 roads.

Direct and Indirect Effects of Additions to the NFTS and Reopened ML 1 Roads

400-meter Zone of Influence

Goshawk Protected Activity Centers are delineated land allocations (SNFPA 2004), comprised of the best 

available goshawk habitat, which are managed specifically for sustaining viable populations of goshawks. 

For all goshawk PACs on the Tahoe NF, the effects of the alternatives are analyzed for the amount of 

habitat fragmentation and edge effects are occurring by considering the Zone of Influence within goshawk 

PACs within 400 meters (0.25 miles) of motorized routes added to the NFTS (Table 3.03-82). Although 

absolute disturbance thresholds for goshawk are not readily available in the literature, Grubb et al. (1998) 

reported that goshawk were found to react negatively (flush) when noise associated with logging trucks 

occurred less than 400 meters (0.25 miles) from nests. Determining the proportion of a goshawk PAC that 

is influenced by motorized routes within 400- meters (0.25 mile) gives a relative index of habitat 

fragmentation or habitat effectiveness at the site specific goshawk territory scale.

Comparing the direct and indirect effects to goshawk PACs within a 400-meter Zone of Influence of 

proposed motorized routes indicates Alternative 1 reduces habitat effectiveness and associated habitat 

fragmentation (including noise disturbance) within PACs by 34%.

All the action alternatives would enhance overall habitat effectiveness compared to Alternative 1. 

When comparing the action alternatives, Alternative 5 reduces habitat effectiveness of goshawk PACs by 

6%. Alternatives 2 and 6 each reduce habitat effectiveness within goshawk PACs by 2%. Alternative 4 

and 7 each reduce habitat effectiveness of goshawk PACs by 1%. Habitat effectiveness within goshawk 

PACs would be enhanced by implementing Alternative 3 since no additions to the NFTS are proposed and 

existing unauthorized routes would be prohibited to cross country travel.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 327

Cumulative Effects of Additions to the NFTS and Reopened ML 1 Roads

400-meter Zone of Influence

Table 3.03-82 and Figure 3.03-8 display the cumulative effects of the proposed alternatives in 

combination with motorized and non-motorized routes on NFS and non-NFS lands. When comparing the 

cumulative effects of routes within a 400-meter Zone of Influence of goshawk PACs (by summing the 

direct and indirect effects of proposed alternatives and the cumulative effects of past, present, and future 

actions), Alternative 1 poses the greatest risk to goshawk PACs, where 83% of PAC acres are 

cumulatively affected within a 400 meter Zone of Influence of all routes both motorized and nonmotorized, and, therefore, adversely impacts habitat connectivity and would result in increased noise 

disturbance associated with routes within goshawk PACs. In addition, Alternative 1 would contribute to 

continued route proliferation on 20,036 PAC acres because unmanaged cross country motorized travel 

would continue into the future. 

All the action alternatives would result in beneficial and reduced cumulative impacts compared to 

Alternative 1, where approximately 51% to 53% of PACs would be cumulatively affected from all routes 

within the 400-meter Zone of Influence. Of the action alternatives, Alternatives 6 has the greatest 

cumulative impacts within goshawk PACs, but only slightly more than the remaining action alternatives 

All action alternatives would result in adding 0-2% increased cumulative impacts from the addition of 

motorized routes and reopened ML 1 roads, combined. Alternative 3 does not directly or indirectly affect 

habitat within the 400-meter Zone of Influence within goshawk PACs, and therefore no cumulative 

impacts would be added to the existing situation. In addition, under the prohibition of cross country travel

(including the use on existing unauthorized motorized routes) all action alternatives would benefit from 

reduced motorized disturbance on 30 to 35% of goshawk PAC acres compared to the No Action 

Alternative. Over time, existing unauthorized routes would eventually become revegetated and recover. 

The rate of recovery would depend on the site specific vegetation and soil conditions. 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

328 – Tahoe National Forest

Table 3.03-82. Cumulative Effects - Proportion of Goshawk Protected Activity Centers within a 400-meter 

(0.25 mile) Zone of Influence of All Routes

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Direct and Indirect effects of proposed alternatives

Motorized route additions to NFTS (negative impact)1 32% 1% 0% 0.3% 1.3% 2.3% 0.7%

Reopened ML 1 Roads 0% 0.2% 0% 0.1% 0.9% 0.5% 0.0%

Motorized routes prohibited to cross country travel

(positive impact) 0 31% 35.4% 35.1% 30.4% 30.2% 31.3%

Cumulative effects of past, present, and proposed actions

Existing motorized routes - NFS lands (negative impact) 36% 36% 36% 36% 36% 36% 36%

Existing motorized routes on private land - non-NFS 

lands (negative impact) 9.6% 9.6% 9.6% 9.6% 9.6% 9.6% 9.6%

Existing non-motorized routes (negative impact) 5.0% 5.0% 5.0% 5.0% 5.0% 5.0% 5.0%

Decommissioned routes (positive impact) 4% 4% 4% 4% 4% 4% 4%

NFTS roads closed with NEPA, pending 

implementation 1.9% 1.9% 1.9% 1.9% 1.9% 1.9% 1.9%

Total Cumulative Effects

Overall Cumulative Effects equals the total of all 

impacts, both positive and negative

82.6% 51.8% 50.6% 51.0% 52.8% 53.4% 51.3%

1 Alternative 1 includes the existing unauthorized routes, while all action alternatives include motorized route additions to the NFTS .

Figure 3.03-8. Cumulative Effects of All Routes within a 400-meter Zone of Influence within Tahoe NF 

Northern Goshawk PACs

Cumulative Effects from Past, Present and Future Vegetation/Fuels Management Projects

and Past Wildfires

Appendix H (Reasonably Foreseeable Projects and Cumulative Effects) provides a list and description of 

past, present, and reasonably foreseeable projects on NFS lands and private lands within the Tahoe NF 

Northern Goshawk 

Protected Activity Centers 

400-Meter Zone of Influence

0%

20%

40%

60%

80%

100%

1 2 3 4 5 6 7

Alternatives

Percent 

% PACs in ZOI
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 329

boundary. Some, but not all, of these activities would contribute to impacts to the Northern goshawk 

within the cumulative effects boundary. 

In order to understand the contribution of past actions to the cumulative effects of the proposed action 

and alternatives, this analysis relies on current environmental conditions as a proxy for the impacts of past 

actions. This is because existing conditions reflect the aggregate impact of all prior human actions and 

natural events that have affected the environment and might contribute to cumulative effects. The 

following information summarizes recent past cumulative impacts from wildfires and fuels/vegetation 

projects that have impacted goshawk habitats.

Between 1994 and 2008, several wildfires resulted in burning approximately 11,000 acres of suitable 

goshawk acres burned affecting 14 goshawk PACs affecting approximately 1,400 acres within goshawk 

PACs. In some cases, goshawk PACs were rendered unsuitable for nesting, and in other cases low or 

moderate severity fires retained habitat conditions suitable for nesting. Since 1990, more than 130,000 

acres of vegetation management activities have occurred on the Tahoe NF. Some, but not all have resulted 

in impacts to goshawk habitats. Between 2001 and 2008, approximately 17,000 acres of forest vegetation 

and fuels thinning and mastication projects were completed, which were designed to reduce the risk of 

additional habitat loss to wildfires. These treatments generally do not result in habitat removal, but may 

result in habitat quality changes. 

Although the timeframe for assessing cumulative effects is 20 years in the past, it is important to 

describe past cumulative effects that are still affecting goshawk habitat on the landscape at present from 

past activities that occurred prior to 20 years ago. Between 1960 and present, private land harvest within 

the boundaries of the Tahoe NF has resulted in approximately 95,000 acres of vegetation treatments 

including clearcuts, sanitation, shelterwood, and thinning. Much of the private land harvest has resulted in 

the loss or reduction in goshawk habitat. These wildfires and vegetation treatment projects have resulted 

in a reduction in the amount and quality of goshawk habitat on the Tahoe NF since 1960.

Thinning projects designed to reduce hazardous fuels would continue to be the primary activity 

affecting goshawk habitat on the Tahoe (see Appendix H, Reasonably Foreseeable Projects and 

Cumulative Effects). Although these treatments may reduce habitat quality (i.e. nesting habitat reduced to 

foraging habitat), it is expected that suitable habitat would be maintained, and it is anticipated that these 

treatments would reduce the amount goshawk habitat potentially lost from future stand replacing wildfires 

(USDA Forest Service 2004). The California Department of Forestry and Fire Protection currently lists 

approximately 12,000 acres of private land within the Tahoe NF administrative boundary for which 

timber harvest plans have been submitted. Timber harvest on private lands is generally more intensive and 

does not typically maintain habitat in a suitable condition for goshawk. 

Sensitive Species Determinations

The Tahoe NF Biological Evaluation for Birds, Mammals, Amphibians, Reptiles, Fish, and Invertebrates 

is incorporated by reference in the Project Record. Based on the northern goshawk analysis of effects, the 

Biological Evaluation for the Tahoe NF Travel Management EIS made a determination that 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

330 – Tahoe National Forest

implementation of all the actions alternatives may affect northern goshawks, but are not likely to lead to a 

trend toward listing or a loss in population viability.

Although some habitat fragmentation and edge effects would occur from the action alternatives, none 

of the action alternatives would likely cause enough fragmentation to be a concern to goshawk population 

viability on the Tahoe NF when considering the combined effects of the alternatives and the additional 

activities occurring within the cumulative effects analysis area. Based on this information, the alternatives

as proposed are not expected to result in a loss of viability or lead to a trend toward Federal listing for the 

northern goshawk. The alternatives would not likely affect Forest-wide northern goshawk population 

trends. However, the uncertainty of long term effects to goshawk from future increases in motorized 

vehicle use on NFS lands poses an unknown risk. It is expected that recreation and motorized use on NFS 

lands will increase. Alternative 1 could cause long-term chronic effects to northern goshawk from 

increased motorized route proliferation over time, and therefore may contribute to downward population 

trends on the Tahoe NF.

When considering the direct, indirect, and cumulative impacts to goshawk, Alternative 1 poses a 

considerable risk to nesting goshawk on the Tahoe NF where 32% of the PAC acres within a 400-meter 

Zone of Influence would be impacted by continued cross country travel, including use on existing 

unauthorized routes. In addition, continued use on existing unauthorized routes under Alternative 1 would 

result in directly and indirectly affecting 68% (66 out of 97) total PACs on the Tahoe NF. Cross country 

travel would continue to increase and proliferate. Goshawk are extremely sensitive to human disturbance 

during the breeding season where continued motorized route proliferation could impact the productivity 

of nesting goshawk which could cause chronic impacts which may ultimately affect the abundance and 

distribution of goshawk on the Tahoe NF. 

All the remaining action alternatives would considerably reduce the impacts associated with 

motorized use of existing unauthorized routes through the prohibition of cross country travel. Alternatives 

5 and 6 are similar in their impacts to the goshawk. Under Alternative 6, a total of 1.6 miles of route 

additions and reopened ML 1 roads would impact 6 goshawk PACs, and Alternative 5 would result in 

impacts to 7 PACs totaling 1.4 miles of route additions and reopened ML 1 roads. Alternatives 2 and 7 

follow with decreasing route miles added to the NFTS, affecting 2-3 PACs totaling approximately 1 mile. 

Alternatives 3 and 4 do not propose any route additions or reopening ML 1 roads, and therefore would not 

affect nesting goshawk.

All the action alternatives would influence between 0-3% of PAC acres within a 400-meter Zone of 

Influence of motorized route additions and reopened ML 1 roads, and therefore would not affect the 

distribution and abundance of goshawk on the Tahoe NF. Therefore, the action alternatives do not affect 

habitat or population trends on the Tahoe NF.

Compliance with the Forest Plan and Other Direction

The Tahoe NF LRMP, as amended by the SNFPA ROD (2004) provided management standards and 

guidelines for the Northern goshawk as follows:
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 331

Evaluate proposals for new roads, trails, off highway vehicle routes, and recreational and other 

developments for their potential to disturb nest sites (Management Standard & Guideline 82). 

Alternatives under the Tahoe NF Travel Motorized Management Project were evaluated for their 

potential to disturb Northern goshawk nest sites at two scales - (1) within goshawk Protected Activity 

Centers (PACs) and (2) within a 0.25 mile radius of known nest sites or activity centers. Analysis of the 

alternatives indicates Alternative 1 disturbs nest sites the most from allowing cross country travel to 

continue on 20,036 PAC acres, affecting 68% of PACs from 42 miles of existing unauthorized routes.

Compared to Alternative 1, the action alternatives all reduce overall effects to goshawk PACs by 

prohibiting cross country travel on 20,036 PAC acres, where disturbance to approximately 30% of PAC 

acres within a 400-meter Zone of Influence would be substantially reduced, and thereby benefiting 

nesting goshawk on the Tahoe NF. The analysis of the alternatives within 0.25 mile of activity centers (i.e. 

nest sites) indicates a similar pattern as found for goshawk PACs. Under the action alternatives, at least 

95% of existing unauthorized routes would be prohibited to cross country travel within 0.25 miles of nest 

sites or nest stands.

Forest Carnivores: American Marten, Pacific Fisher,

Sierra Nevada Red Fox and Wolverine

Forest Carnivores include the American marten, Pacific fisher, the Sierra Nevada red fox, and Wolverine. 

The Sierra Nevada red fox and the wolverine are addressed under the Wide-ranging Carnivore Group. 

This section will focus on the marten and fisher. Impacts to the marten and fisher will be considered 

together, since effects to these species are similar. More detailed information for these species can be 

found in the Biological Evaluation and Management Indicator Species reports, which are hereby 

incorporated by reference. Limited research or information on road and trail impacts to Forest Carnivores 

is available in the literature, but some information is available as described below for species considered 

here.

The Tahoe NF developed a Forest Carnivore Network in 1998 by modeling suitable marten and fisher 

habitat using a focal mean analysis based on the home ranges of marten and fisher. The purpose of the 

Forest Carnivore Network is to provide a framework for managing and maintaining linkages and 

connectivity for Forest Carnivore species including the marten, fisher, Sierra Nevada red fox, and the 

wolverine. Forest Carnivores are considered to be interior Forest Species where habitat fragmentation is a 

concern.

American Marten and Pacific Fisher: Affected Environment

Martens prefer coniferous forest habitat with large diameter trees and snags, large down logs, moderateto-high canopy closure, and an interspersion of riparian areas and meadows. Important habitat attributes 

are: vegetative diversity, with predominately mature forest; snags; dispersal cover; and large woody 

debris (Allen 1987).
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

332 – Tahoe National Forest

At a landscape scale, patches of preferred habitat and the distribution of openings with respect to 

habitat patches may be critical to the distribution and abundance of martens (USDA 1994). As landscapes 

become fragmented, the combination of increasing isolation and decreasing patch size of suitable habitat 

compounds the results of simple habitat loss (Andren 1994). For species like marten, this is likely to 

result in a decrease of greater magnitude than can be explained solely by the loss of suitable habitat. 

Marten may be a species that demonstrate exponential population declines at relatively low levels of 

fragmentation (Bissonette et al. 1997, in USDA Forest Service 2004). 

The Tahoe NF falls within an area considered to be a distribution gap within the range of the fisher 

(Zielinski et al. 2005). However, roads can impact fisher in ways similar to the marten through direct 

mortality and habitat fragmentation. Suitable habitat for the fisher occurs primarily on the west side of the 

Tahoe NF.

Summary of road and trail associated factors to marten and fisher:

• Mortality or injury resulting from a motorized vehicle running over or colliding with an animal

• Loss and resulting fragmentation of habitat due to the establishment of roads or trails and 

associated human activities

• Changes to habitat microclimate associated with the edge induced by roads or trails

• Reduction in density of snags and down logs due to their removal near roads as facilitated by road 

access

• Collection of live animals for use as pets as facilitated by the physical characteristics of roads or 

trails or by road or trail access

• A physical human-induced change in the environment that provides access for competitors or 

predators that would not have existed otherwise

• Displacement of individual animals from a specific location that is being used for reproduction 

and rearing of young

• Increase in heart rate or stress hormones when near a road or trail

Based upon a review of the literature, fisher and marten were found likely to be affected by the same 

road and motorized trail-associated factors: trapping, poaching, collisions, displacement or avoidance, 

habitat loss or fragmentation, snag reduction, down log reduction, edge effects, movement barrier or filter, 

and route for competitors (Gaines et al. 2003, Buskirk and Ruggierro In USDA 1994). These factors are 

discussed below.

Human-caused mortality: Marten are known for their vulnerability to trapping in many parts of their 

range. In California, however, body-gripping traps have been banned since 1998 and, as a result, the 

likelihood of incidental capture of marten by legal fur trapping has been dramatically reduced. Illegal 

harvest threats remain and could increase in relation to greater accessibility. At present, illegal trapping or 

shooting of marten is not known to be a substantial source of mortality (USDA Forest Service 2001). The 

increased opportunity for poaching provided by increased public access may represent a substantial risk 

for fisher, based upon findings in the southern Sierra Nevada. Of nine recently documented fisher 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 333

mortalities, two were suspected of being the result of poaching (Truex et al 1998 In USDI Fish and 

Wildlife Service 2004). 

Collision: Highways and roads can result in the direct and indirect mortality of martens and fisher. 

Road collisions with vehicles have been identified as a source of marten mortality (Buskirk and Ruggerio 

1994), including in the Sierra Nevada (Spencer 1981, Martin 1987), and fisher mortality (Heinemeyer 

1993 In USDA 2001). Marten and fisher road mortality from highway collisions on the Tahoe NF may be 

of concern since Interstate-80, and State Highways 89, 49, and 20 bisect their habitat. Approximately 3.4 

percent of 147 radio-collared fishers studied in Massachusetts (York 1996) and Maine (Krohn et al. In 

USDA 1994) were killed by vehicles. The risk of collision mortality increases with road density, but 

possibly increases with the density of highways and freeways where vehicle speeds are highest. Collisions 

are much less likely to occur along the slower-speed native surface roads and trails that are being 

evaluated in this project.

Habitat Loss and Fragmentation, Edge Effects, Movement Barriers, Displacement or 

Avoidance: Roads and trails can fragment habitat, thus affecting the ability of marten and fisher to use 

otherwise suitable habitat on either side of the route. Martens are known to be sensitive to changes in 

overhead cover, such as can result from roads or trails (Hargis and McCullough 1984, USDA 1994). 

Roads can contribute to habitat fragmentation for fisher as well because fishers generally avoid entering 

“Open Areas” that have no overstory or shrub cover; roads, and the associated presence of vehicles and 

humans can cause animals to modify their behavior near roads (USDA Forest Service 2001). Previous 

studies have reported a negative correlation between detections of fisher and roads (Dark 1997, Golightly 

et al. 2006). Road construction associated with timber harvest activities could directly and indirectly 

affect fishers. If fishers avoid areas in proximity of roads, then these areas constitute habitat loss. 

The loss and fragmentation of suitable habitat by roads and development is thought to have played a 

significant role in both the loss of fisher from the central Sierra Nevada and its failure to re-colonize this 

area (USFWS 2004). Campbell (2004, in USFWS 2004) found that sample units within the central and 

southern Sierra Nevada region occupied by fishers were negatively associated with road density. This 

relationship was significant at multiple spatial scales (from 494 to 7,413 acres). The USFWS (2004) 

concluded that, “vehicle traffic during the breeding season in suitable habitat may impact foraging and 

breeding activity” and that “hiking, biking, off-road vehicle and snowmobile trails, may adversely affect 

fishers.” Dark (1997) found that fishers in the Shasta-Trinity National Forest used landscapes with more 

contiguous, unfragmented forests and less human activity. These indirect effects on fisher habitat could 

negatively affect the ability for fishers to be successfully reintroduced to the Tahoe NF.

Robitaille and Aubrey (2000), studied marten in an area of low road density and traffic (primarily 

logging roads), and found that marten use of habitat within 300 and 400 meters of roads was significantly 

less than habitat use at 700 or 800 meters distance. Although marten are detected in close proximity to 

roads, it appears that significantly less marten activity occurs within these zones.

If highways, with their high traffic speeds, jersey barriers, and often steep side-slopes, limit the 

success and frequency of marten crossings, then effects on marten dispersal may be of concern. Interstate 

I-80 and State highways 89, 49, and 20 bisect marten habitat. If marten avoid these highways, then marten 
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334 – Tahoe National Forest

populations could become fragmented into small isolated populations. In their assessment of connectivity 

in the California landscape, Penrod et al. (2001) identified Interstate-80 in particular as a threat to wildlife 

movement, and roads and highways in general as the most common barriers to movement.

Roads may decrease prey and food availability for marten and fisher (Allen 1987) due to prey 

population reductions from road kills and/or behavioral avoidance of roads. Occasional one and two lane 

forest roads with moderate levels of traffic should not limit marten movements.

In a study conducted on the Lake Tahoe Basin Management Unit and Sierra National Forest, however, 

Zielinski (2007) found that marten occupancy or probability of detection did not change in relation to the 

presence or absence of motorized routes and OHV use when the routes (plus a 50 meter buffer) did not 

exceed about 20 percent of a 50 square kilometer area, and traffic did not exceed one vehicle every 2 

hours. The study did not, however, measure behavioral changes or changes in use patterns and the study 

authors caution that application of their results to other locations would apply only if OHV/OSV use at 

the other locations is no greater than reported in their study.

Standards and guidelines in the Sierra Nevada Forest Plan Amendment ROD (2004), provides 

management direction for habitat connectivity for old forest associated species to “minimize old forest 

habitat fragmentation” and “assess the potential impacts of projects on the connectivity of habitat for old 

forest associated species,” particularly marten and fisher.

Snag and Down Log Reduction: High levels of coarse woody debris (snags, downed logs, root 

masses, large branches) are an essential component of marten habitat, especially during the winter months 

when marten require subnivian structures for cover and hunting opportunities. In addition, large logs with 

cavities provide rest and den sites for marten and fisher. Activities that remove large logs are therefore 

likely to degrade marten and fisher habitat (USDA 1994). Hazard tree removal along roads will reduce 

numbers of snags (future down logs) within a distance of about 60 meters alongside roads. In addition,

motorized routes provide access for fuelwood collection, which would also contribute to decreased levels 

of snag and down wood within roadside corridors. However, snag removal within 60 meters of roads may 

be incidental compared to the displacement and avoidance factors that seem to influence marten habitat 

use adjacent to motorized routes. 

Disturbance at Meadows (Marten only): Various studies in the Sierra Nevada indicate marten have 

a strong preference for meadows and forest-meadow edges for foraging (USDA Forest Service 2001). 

While marten use small openings, and particularly meadows for foraging, these openings must occupy 25 

percent or less of the landscape (Hargis and Bissonette 1999; Potvin et al. 2000). Microtine rodents 

(meadow voles) are important for the marten diet, and therefore, the quality of meadow habitat (especially 

meadows surrounded by mature lodgepole and red fir forests) influences the quality of marten habitat 

(Spencer et al. 1983). Routes that are adjacent to and intersect meadows can alter meadow hydrology and 

vegetation which may have a negative effect on prey abundance. The combination of route use and 

increased human activity, as well as the potential impacts of routes upon meadow vegetation, may result 

in loss of these more easily exploitable “prey patches.”
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 335

American Marten and Pacific Fisher: Environmental Consequences

Based upon a review of the literature, fisher were found likely to be affected by the same road and 

motorized trail-associated factors as marten: trapping, poaching, collisions, displacement or avoidance, 

habitat loss or fragmentation, snag reduction, down log reduction, edge effects, movement barrier or filter, 

and route for competitors (Gaines et al. 2003, Buskirk and Ruggierro In USDA 1994). The current 

absence of fisher on the Tahoe NF renders temporal risk factors moot, but this analysis will be conducted 

to analyze impacts of the alternatives to fisher if populations were to be re-established on the Tahoe NF.

Environmental consequences for marten and fisher are analyzed at three different scales - within old 

forest coniferous habitat (defined as CWHR types 4M, 4D, 5M, 5D and 6), Old Forest Emphasis Areas 

(OFEAs), and Tahoe NF Forest Carnivore Network. Old forest coniferous habitat is considered to be 

suitable for marten (USDA 2004). The OFEAs, as previously described, are land allocations designated to 

manage for old forest dependent species, including marten. Although no management direction is 

specifically designated within the Tahoe NF Forest Carnivore Network, the network provides a broad 

framework for considering habitat connectivity issues for Forest Carnivores, including the marten. These 

three scales are used for comparison, since habitat connectivity within these habitats are important 

considerations for marten populations. Although all 3 scales have considerable overlap because older 

forest types are included in all of them, there are slight differences between them because they were 

derived in different manners. The old forest coniferous habitat types are comprised of individual patches 

of habitat types that may not necessarily be connected, whereas both the OFEAs and the Carnivore 

Network incorporates larger blocks of older forest types. 

Indicators used to Measure Effects

Cross Country Travel and Establishment of “Open Areas”: Cross country travel and establishment of 

“Open Areas” are evaluated for the alternatives to determine the impacts to fisher and marten habitats 

within old forest coniferous CWHR habitat, Old Forest Emphasis Areas (OFEAs), and Tahoe NF Forest 

Carnivore Network.

Additions to the NFTS and Reopened ML 1 Roads: Motorized route additions to the NFTS and 

reopened ML 1 roads are evaluated for their potential to directly and indirectly affect marten and fisher 

habitats by assessing the Zone of Influence within 300 meters and meadow habitats as described below.

Zone of Influence: Studies indicate marten habitat use declines within a distance within exceeding 

300 meters from roads. For this analysis, the proportion of marten habitat occurring within a Zone of 

Influence of 300 meters from motorized routes was determined. Within this zone, some factors would be 

expected to influence a smaller area (probably about 60 meters) adjacent to motorized routes; thus a 

second Zone of Influence of 60 meters was analyzed for the DEIS and is available in the Project Record. 

These factors include changes to habitat such as fragmentation, edge effects, and the reduction of snags 

and down wood. Thresholds associated with these measures have not been established, but relative 

changes in habitat effectiveness for marten and fisher can be evaluated and compared.

Meadows Affected by Motorized Routes (Marten only): In the Sierra Nevada, marten are known to 

have a strong preference for meadows and forest-meadow edges for foraging (USDA Forest Service 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

336 – Tahoe National Forest

2001). The number of meadows that are intersected by miles of motorized route additions and reopened 

ML 1 roads is used to measure the effects on wet meadow habitat important for the marten.

Changes to the NFTS (Change in Class of Vehicles and Wet Weather Seasonal Restrictions): The 

effects of Change in class of vehicles and wet weather seasonal restrictions are discussed previously 

under the section “Effects Common to All Old Forest Conifer Associated Species.”

Direct and Indirect Effects: American Marten and Pacific Fisher

Cross Country Travel

Motorized cross country travel is not prohibited under Alternative 1, where habitat for American marten 

and Pacific fisher habitat would be at risk of habitat fragmentation, disturbance, avoidance, and 

abandonment from motorized use within 394,847 OFEA acres, 267,952 late-seral habitat (CWHR 4M, 

4D, 5M, 5D, and 6) acres, and 396,602 Carnivore Network acres (acres may overlap). All the action 

alternatives prohibit cross country travel on over 250,000 acres of marten and fisher habitat, where habitat 

fragmentation, disturbance, avoidance, and abandonment would be reduced.

Establishment of “Open Areas”

Alternative 2 establishes motorized “Open Areas” at Greenhorn (60 acres), and Reservoir Areas at 

Stampede, Boca, and Prosser Reservoirs (2,589 acres). Alternative 6 establishes 244 acres of “Open 

Areas” at the reservoirs. In general, suitable habitat for marten and fisher is not available in these areas, 

and therefore motorized use of these areas would not alter habitat for these species. The Greenhorn area is 

below the elevation range for the marten. The reservoirs’ “Open Areas” are also devoid of vegetation and 

occur within eastside pine and sagebrush/bitterbrush habitats that are generally not important for these 

species. If animals are traveling through in the vicinity of these “Open Areas,” some direct disturbance 

could occur, although this is expected to be low.

Zone of Influence

Additions to the NFTS (300-meter Zone of Influence): The proportion of Carnivore Network, OFEAs, 

and Old Forest CWHR types within a 300-meter Zone of Influence of motorized route additions is 

displayed in Table 3.03-83.

Within a 300-meter Zone of Influence, Alternative 1 would result in the greatest amount of habitat 

fragmentation and reduced habitat connectivity within the Carnivore Network, late-seral coniferous forest 

habitat, and within OFEAs, where marten and fisher habitat suitability may be reduced. Alternative 1 

results in contributing to 27% reduction in habitat connectivity within the Carnivore Network, a 22% 

reduction in habitat connectivity in Old Forest Emphasis Areas, and a 22% reduction in habitat 

connectivity in Old Forest habitat types 

Within a 300-meter Zone of Influence, all the action alternatives would increase habitat connectivity 

within the Carnivore Network OFEAs, and old forest CWHR habitats compared to Alternative 1.

Alternative 3 would improve habitat connectivity the greatest, and Alternatives 5 and 6 would reduce
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 337

habitat connectivity the least. The differences between the action alternatives would result in affecting 

from 0 to 2% within a 300 meter Zone of Influence of motorized route additions.

Table 3.03-83. Percent of Carnivore Network, OFEAs, and Old Forest Habitat (CWHR 4M, 4D, 5M, 5D, 6) within 

a 300-meter “Zone of Influence” of motorized route additions to the NFTS

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Carnivore Network 27% 2% 0% 1% 2% 2% 1%

Old Forest Emphasis Areas (SNFPA) 22% 1% 0% <1% 2% 2% <1%

Old Forest Habitat (CWHR 4M, 4D, 5M, 5D, 6) 22% 1% 0% 1% 2% 2% 1%

* Alternative 1 includes the existing unauthorized routes, while all action alternatives include proposed motorized route additions to 

the NFTS.

Reopened ML 1 Roads (300-meter Zone of Influence): Alternatives 1 and 3 do not propose to 

reopen any ML 1 roads within the Carnivore Network, OFEAs, and old forest CWHR habitats, and would 

not affect habitat effectiveness. Alternative 5 proposes to open the most ML 1 roads where approximately 

2% of the Carnivore Network, OFEAs, and old forest CWHR habitats would be directly and indirectly 

affected. The remaining action alternatives would affect up to 0.2% of the Carnivore Network, OFEAs 

and old forest CWHR habitat from reopening ML 1 roads as shown in Table 3.03-84. This represents a 

small influence from reopened ML 1 roads within the Carnivore Network, OFEAs, and old forest CWHR 

habitat, which would not increase habitat fragmentation and would therefore maintain habitat connectivity 

for marten and fisher across the Tahoe NF.

Table 3.03-84. Percent of Carnivore Network, OFEAs, and Old Forest Habitat (CWHR 4M, 4D, 5M, 5D, 6) within 

a 300-meter “Zone of Influence” of reopened ML 1 roads 

Alternatives Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Carnivore Network 0% 0.1% 0% 0.2% 2.2% 0.3% 0.1%

Old Forest Emphasis Areas (SNFPA) 0% 0.1% 0% 0.1% 1.7% 0.2% 0%

Old Forest Habitat (CWHR 4M, 4D, 5M, 5D, 6) 0% 0.1% 0% 0.1% 1.8% 0.2% 0%

Wet Meadows (Marten only)

Cross Country Travel: Motorized cross country travel would continue under Alternative 1, no action, 

where wet meadows providing foraging habitat for marten could receive damage from motorized vehicle 

use. However, under current policy, it is illegal to cause resource damage in wet meadows. Under all the 

action alternatives motorized cross country travel would be prohibited on 9,167 acres of wet meadow 

across the Forest, where marten prey habitat would benefit.

Additions to the NFTS: The number of wet meadows that are intersected by proposed motorized 

route additions for the alternatives is shown in Table 3.03-85. Out of 518 wet meadows on the Tahoe NF, 

Alternative 1 would result in 87 meadow sites (17%) intersected by 16 miles of existing unauthorized 

routes. Motorized use on these existing unauthorized routes could directly disturb marten while foraging 

within and adjacent to these 87 meadow sites. These 16 miles of routes intersecting marten meadow 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

338 – Tahoe National Forest

habitat could continue to receive cross country travel with the potential to indirectly affect the distribution 

and abundance of marten and its prey species. Routes through meadows can result in changes in meadow 

condition, particularly from meadow drying, loss of meadow vegetation, and through soil compaction 

and/or erosion. Loss of meadow vegetation and drying of meadows can affect the abundance and 

distribution of prey species available to marten, particularly meadow voles.

All the action alternatives would greatly reduce the impacts to wet meadows compared to Alternative 

1. Amongst the action alternatives, Alternative 6 intersects the greatest number of meadows (25) for over 

1 mile of motorized route additions. The majority of these additions are routes which access dispersed 

sites (33 out of 39 routes). The majority of the dispersed routes are short spur routes that total less than 

0.10 miles in length. Alternatives 2 and 5 would each result in 9 wet meadows (2%) that are intersected 

by motorized route additions to the NFTS. Alternatives 4 and 7 result in approximately less than 1% wet 

meadows intersected by motorized route additions. Alternative 3 does not propose any motorized route 

additions, and therefore would not affect marten prey species within wet meadows.

Table 3.03-85. Meadows Intersected by Motorized Route Additions to the NFTS

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Number of Wet Meadows Intersected by motorized 

route additions (518 total)

87 9 0 3 9 25 2

Percent Wet Meadows Affected 17% 2% 0% <1% 2% 5% <1%

Miles of Route Additions Intersecting Wet Meadows 16.2 0.5 0 0.04 0.5 1.35 0.31

*Alternative 1 includes unauthorized routes associated with continued cross country travel while all the action alternatives include 

motorized route additions.

Reopened ML 1 Roads: Only Alternative 5 would reopen ML 1 roads with the potential to adversely 

affect 2 meadows totaling 0.3 miles, which could affect the distribution and abundance of marten and its 

prey. Although this only represents less than 1% of all wet meadows on the Tahoe NF, there could be site 

specific impacts where meadow degradation may occur from use on these roads. Refer to Table 3.03-86.

Table 3.03-86. Meadows Intersected by Reopened ML 1 Roads 

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Number Wet Meadows Intersected by motorized route 

additions (518 total)

0 0 0 0 2 0 0

Percent Wet Meadows Affected 0% 0% 0% 0% <1% 0% 0%

Miles of Reopened ML 1 Roads Intersecting Wet 

Meadows 

0 0 0 0 0.3 0 0

Summary of Direct and Indirect, Impacts to American Marten and Pacific Fisher 

When considering all the direct, indirect, and cumulative impact to the American marten and the Pacific 

fisher within American marten and Pacific fisher habitat, Table 3.03-87 summarizes the overall net effect 

to the American marten and Pacific fisher from the proposed actions from motorized route additions to the 

NFTS, prohibition of cross country travel, and change in seasonal of use.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 339

Table 3.03-87. American marten and Pacific fisher - Summary of Overall Net Direct and Indirect Effects

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres Cross 

Country Travel 

Prohibited

Carnivore Network 0 401,428 401,428 401,428 401,428 401,428 401,428

OFEAs 0 398,060 398,060 398,060 398,060 398,060 398,060

Old Forest CWHR 

Types

0 268,895 268,895 268,895 268,895 268,895 268,895

Motorized Route Additions to the NFTS

Trend of Effect Negative Minimal 

Negative 

Effects

No Effect Minimal 

Negative 

Effects

Minimal 

Negative 

Effects

Minimal 

Negative 

Effects

Minimal 

Negative 

Effects

ZOI Carnivore Network 27% 2% 0% 1% 2% 2% 1%

OFEAs 22% 1% 0% <1% 2% 2% <1%

Old Forest CWHR types 22% 1% 0% 1% 2% 2% 1%

Routes In Wet Meadows (miles) 16.2 0.5 0 0.04 0.5 1.35 0.31

Establishment of “Open Areas” No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Changes 

to the 

NFTS

Change in Season of Use No Effect No Effect No Effect Beneficial 

from reduced 

disturbance

Beneficial 

from reduced 

disturbance

Beneficial 

from reduced 

disturbance

No Effect

Change in Class of Vehicles No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Reopened 

ML 1 Roads

Trend of Effect No Effect No Effect No Effect Negative Negative No Effect No Effect

ZOI Carnivore 

Network

0% 0.1% 0% 0.2% 2.2% 0.3% 0.1%

OFEAs 0% 0.1% 0% 0.1% 1.7% 0.2% 0%

Old Forest 

CWHR

0% 0.1% 0% 0.1% 1.8% 0.2% 0%

In Wet Meadows 

(miles)

0 0 0 0 0.3 0 0

Amendments to the Forest Plan No Effect No Effect No Effect No Effect No Effect No Effect No Effect
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

340 – Tahoe National Forest

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Overall Net Effect of Proposed Actions Negatively 

affects 22-27% 

habitat in ZOI, 

and where 

motorized cross 

country travel 

continued on 

unauthorized 

routes affecting 

between 

268,895 and 

401,428 acres.

3rd most 

beneficial 

alternative, 

route additions 

affects between 

1-2% habitat in 

ZOI.

Benefits from 

cross country 

travel prohibited 

on 268,895 and 

401,428 acres.

Most beneficial 

alternative 

from since no 

routes added 

or reopened.

Benefits from 

cross country 

travel 

prohibited on 

268,895 and 

401,428 acres.

2nd most 

beneficial 

alternative 

shared with Alt 

7; about 1% 

habitat 

affected in ZOI 

of route 

additions.

Benefits from 

motorized 

cross country 

travel

prohibited on 

268,895 and 

401,428 

habitat acres.

5th most 

beneficial 

alternative, 

approx. 4% 

habitat 

affected from 

ZOI of route 

additions and 

reopened ML 1 

roads. 

Benefits from 

motorized 

cross country 

travel

prohibited on 

268,895 and 

401,428 

habitat acres.

4th most 

beneficial 

alternative; 

approx. 2% 

habitat 

affected in ZOI 

of route 

additions. 

Benefits from 

motorized 

cross country 

travel

prohibited on 

268,895 and 

401,428 

habitat acres.

2nd most 

beneficial 

altenative 

shared with Alt 

4; about 1% 

habiat affected 

in ZOI of route 

additions. 

Benefits from 

motorized 

cross country 

travel

prohibited on 

268,895 and 

401,428 

habitat acres.

*Alternative 1 includes existing unauthorized routes that would continue with the continuance of cross country travel, while all the action alternatives include proposed route additions.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 341

Cumulative Effects

Indicators to Measure Cumulative Effects

Motorized Route Density: The magnitude of effects caused by habitat loss and fragmentation, 

displacement or avoidance, routes for competitors will correspond, to some degree, with the density of 

motorized routes and the associated extent of public access and use. Marten have been found to be less 

active near motorized routes, and higher densities of motorized routes are therefore likely to result in less 

marten activity or occurrence in an area. In general, several studies indicate that factors associated with 

higher route densities are negatively correlated with numbers of marten and fisher. Habitat fragmentation 

effects also increase in relation to increased route densities. Forest Plan standards and guidelines direct 

that projects “minimize old forest habitat fragmentation” and emphasize old forest habitat connectivity. 

Since the “Old Forest Emphasis Area” land allocation and the Tahoe Forest Carnivore Network are 

intended to provide for structurally complex forests and connectivity of old forest habitat, route densities 

within this land allocation are evaluated.

Cross Country Travel: Cumulative effects of Motorized cross country travel are compared for the 

alternatives within Carnivore Network, OFEAs, and Old Forest CWHR habitats.

300 meter Zone of Influence: The cumulative effects within a 300-meter Zone of Influence of 

motorized and non-motorized routes are evaluated at three scales-- Carnivore Network, OFEAs, and old 

forest CWHR habitat types. The three scales are similar in attributes and overlap in some locations, but 

vary slightly in terms of patch size, distribution, and condition across the Tahoe NF landscape. Each of 

the scales was developed with different criteria. Analyzing the Zone of Influence within the three scales 

provide a relative comparison of how different types of “old forest” designations may be affected by 

motorized and non-motorized activities resulting in changes to habitat connectivity for marten and fisher 

at a large landscape scale. 

Cumulative Effects of Motorized Route Density 

The proportion of area with moderate to high motorized route densities (greater than 2 miles per square 

mile) are shown in Table 3.03-88 within old forest CWHR habitat types (4M, 4D, 5M, 5D and 6), Old 

Forest Emphasis Areas, and the Tahoe Forest Carnivore Network for each of the alternatives. Habitat 

connectivity for marten within these areas is an important consideration, since higher route densities may 

affect marten population densities. Alternative 1 would result in 86% to 89% of areas managed for marten 

(OFEAs-89%, Carnivore Network-87%, and old forest coniferous habitat - 86%) with motorized route 

densities that are greater than 2 miles per square mile. Since marten may demonstrate population declines 

at relatively low levels of fragmentation (USDA Forest Service 2001), Alternative 1 could result in 

population declines, especially since cross country motorized travel would continue and motorized route 

proliferation would be expected to increase over time.

The action alternatives result in about 10% less of the landscape with moderate to high motorized 

route densities when compared to Alternative 1. These alternatives result 74-80% of areas managed for 

marten (OFEAs, Forest Carnivore Network, and late-seral coniferous forest forests) with route densities 
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342 – Tahoe National Forest

exceeding 2 miles per square mile, which is still relatively high. The majority of the areas with higher 

route densities are comprised of the existing road system. Also, the majority of marten and fisher habitats 

have route densities of 2-4 mi/mi2

.

As motorized route densities are reduced, habitat connectivity for marten and fisher are likely to be 

improved (Robitaille and Aubry 2000). The connectivity of higher elevation habitats that are not as 

affected by motorized routes is improved substantially in the action alternatives as compared to the 

Alternative 1. On the Tahoe NF, there are 11 Inventoried Roadless Areas (IRAs). These areas include 

Westside mixed conifer, red fir and lodgepole pine types that are preferred habitat for marten in the Sierra 

Nevada (USDA Forest Service 2001) and increase the size and connectivity of undisturbed habitat that 

occurs in the wilderness areas. Since Alternative 3 does not add any motorized routes to the NFTS in 

IRAs, it provides greater connectivity of marten and fisher habitat as compared to the other alternatives 

which propose some motorized route additions to the NFTS within these areas.

Table 3.03-88. Proportion of Tahoe NF Lands with Motorized Route Densities greater than 2 miles/square mile 

within Old Forest CWHR type, Old Forest Emphasis Areas, and Tahoe Carnivore Network

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Old forest CWHR types (4M, 4D, 5M, 5D, & 6) 86% 75% 75% 75% 78% 75% 75%

Old Forest Emphasis Areas 89% 76% 76% 76% 81% 78% 76%

Carnivore Network 87% 74% 74% 74% 78% 75% 74%

*For Alternative 1, route density within mature and old forest coniferous habitat (CWHR 4M, 4D, 5M, 5D & 6), Old Forest Emphasis 

Areas (OFEAs), and Carnivore Network includes existing motorized unauthorized routes, as well as existing NFTS routes and nonNFTS routes.

Cross Country Travel

Table 3.03-89 shows the acres of cross country travel prohibited to motor vehicle use for the alternatives, 

including proposed cross country prohibitions and current prohibitions designated under the Tahoe Land 

Management Plan (LRMP). Cross country travel would continue under Alternative 1on between 268,895

and 401,428 acres where marten and fisher habitat would result in significant habitat fragmentation and 

disturbance from motorized cross country travel within the Tahoe NF Carnivore Network, OFEAs, and 

old forest CWHR types, all of which are important landscapes to maintain habitat connectivity and 

integrity. Under Alternative 1, only existing LRMP motorized cross country prohibitions on 17,892 and 

39,428 acres would occur.

All the action alternatives would cumulatively benefit marten and fisher habitat at all three landscape 

scales where cross country travel would be prohibited, ranging from a total of 286,787 acres to 437,488 

acres, including LRMP areas currently prohibited to motor vehicles. Under the action alternatives reduced 

disturbance and habitat fragmentation would be significantly beneficial to marten and fisher and their 

habitat where habitat connectivity would be enhanced and maintained 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 343

Table 3.03-89. Cross Country Travel Cumulative Effects in Carnivore Network, OFEAs, and Old Forest CWHR 

habitat

Carnivore Network

Existing LMP cross country travel prohibition (acres) 34,303 34,303 34,303 34,303 34,303 34,303 34,303

Proposed cross country travel prohibition (acres) 0 401,428 401,428 401,428 401,428 401,428 401,428

Cumulative Total 34,303 435,731 435,731 435,731 435,731 435,731 435,731

OFEAs

Existing LMP cross country travel prohibition (acres) 39,428 39,428 39,428 39,428 39,428 39,428 39,428

Proposed cross country travel prohibition (acres) 0 398,060 398,060 398,060 398,060 398,060 398,060

Cumulative Total 39,428 437,488 437,488 437,488 437,488 437,488 437,488

Old Forest CWHR types (4M, 4D, 5M, 5D, & 6)

Existing LMP cross country travel prohibition (acres) 17,892 17,892 17,892 17,892 17,892 17,892 17,892

Proposed cross country travel prohibition (acres) 0 268,895 268,895 268,895 268,895 268,895 268,895

Cumulative Total 17,892 286,787 286,787 286,787 286,787 286,787 286,787

300-meter Zone of Influence

The cumulative proportion of Carnivore Network, OFEAs, and Old Forest CWHR occurring within a 

300-meter Zone of Influence of motorized route additions to the NFTS, existing motorized routes on NFS 

and non-NFS lands, and non-motorized routes for all the alternatives is shown in Tables 3.03-90, -91, and 

-92. In addition, the zones of influence where positive cumulative impacts are realized where motorized 

routes are decommissioned or cross country travel is prohibited, including use on unauthorized motorized 

routes, is also displayed for each of the alternatives.

Within the Carnivore Network, OFEAs and Old Forest habitat types, Alternative 1 would pose the 

greatest risk to habitat fragmentation where considerable cumulative impacts would be added to existing 

cumulative effects to marten and fisher. Existing motorized routes in the NFTS influence between 30 and 

32% of marten and fisher habitat within the Carnivore Network, OFEAs, and Old Forest CWHR types. 

Under Alternative 1, continued motorized cross country travel, with continued use on existing 

unauthorized routes, would influence an additional 22 to 27% (cumulative impact score) of the Carnivore 

Network, OFEAs, and Old Forest habitat types, further reducing habitat connectivity, where cumulative 

impacts to marten and fisher habitat would be significant. Future route proliferation due to unmanaged 

cross country travel would further increase habitat fragmentation which could seriously limit the 

distribution of marten and the future reestablishment potential of the fisher on the Tahoe NF.

Compared to Alternative 1, all the action alternatives would benefit fisher and marten habitats by 

reducing habitat fragmentation by at least 20%. In general, Alternative 5 would increase habitat 

connectivity the least and Alternative 3 would increase habitat connectivity the most at all three landscape 

scales.

The cumulative impact added to existing conditions for all the action alternatives from motorized 

route additions and reopened ML 1 roads would not affect the overall distribution and abundance of 

marten on the Tahoe NF, and would not affect the future reintroduction of fisher on the Tahoe NF. 

Therefore, population viability for the marten would not be affected by any of the action alternatives.
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344 – Tahoe National Forest

Under these alternatives cross country motorized travel would be prohibited and future route proliferation 

should be minimized.

Table 3.03-90. Cumulative Percent of Carnivore Network within a 300-meter Zone of Influence of Routes

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Direct and Indirect Effects of Proposed Alternatives

Motorized route additions to the NFTS (negative 

impact)1 27% 2% 0% 1% 2% 2% 1%

Reopened ML 1 roads 0% 0% 0% 0% 2% 0% 0%

Existing Unauthorized routes where cross country 

travel is prohibited (positive impact)

0% 25% 26% 26% 24% 25% 26%

Cumulative Effects of Past and Present

Existing motorized routes - NFS lands (negative 

impact)

31% 31% 31% 31% 31% 31% 31%

Existing motorized routes on private land - nonNFS lands (negative impact)5% 5% 5% 5% 5% 5% 5%

Existing non-motorized routes (negative impact)2 6% 6% 6% 6% 6% 6% 6%

Decommissioned routes (positive impact) 2% 2% 2% 2% 2% 2% 2%

Roads closed by previous NEPA decisions, 

pending implementation (positive impact)

1% 1% 1% 1% 1% 1% 1%

Total Cumulative Effects

Overall Cumulative Impact Score = Sum Total 

of All Routes (Note: Some overlap may occur 

where route categories intersect)

69% 44% 42% 43% 46% 44% 43%

1

Motorized Additions - Alternative 1 includes use on existing unauthorized routes associated with continued cross country travel

2

Non-motorized -assumption made that non-motorized impact is limited to 60 meters from trail and that no impact occurs beyond 60 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 345

Table 3.03-91. Cumulative Percent of Old Forest Emphasis Areas within a 300-meter Zone of Influence

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Direct and Indirect Effects of Proposed Alternatives

Motorized route additions to the NFTS (negative impact)1 22% 1% 0% <1% 2% 2% <1%

Reopened ML 1 roads (negative) 0% 0% 0% 0% 2% 0% 0%

Existing unauthorized routes where cross country travel 

prohibited (positive impact)

0% 21% 22% 21% 20% 21% 21%

Cumulative Effects of Past and Present

Existing motorized routes - NFS lands (negative impact) 32% 32% 32% 32% 32% 32% 32%

Existing motorized routes on private land - non-NFS lands 

(negative impact)

12% 12% 12% 12% 12% 12% 12%

Existing non-motorized routes (negative impact)2

5% 5% 5% 5% 5% 5% 5%

Decommissioned routes (positive impact) 2% 2% 2% 2% 2% 2% 2%

Roads closed by previous NEPA decisions, pending 

implementation (positive impact)

1% 1% 1% 1% 1% 1% 1%

Total Cumulative Effects

Overall Relative Cumulative Impact Score (Percent of 

Tahoe NF OFEA) = Sum Total of all routes both positive 

and negative (Note: Some overlap may occur where route 

categories intersect)

71% 50% 49% 49% 53% 51% 49%

1

Motorized Additions - Alternative 1 includes use on existing unauthorized routes associated with continued cross country travel

2

Non-motorized -assumption made that non-motorized impact is limited to 60 meters from trail and that no impact occurs beyond 60 
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346 – Tahoe National Forest

Table 3.03-92. Cumulative Percent of Forest-wide Late-seral Forest (CWHR 4, 5, 6) within 300-meter “Zone of 

Influence” of Routes

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Direct and indirect effects of Proposed Alternatives

Motorized route additions to the NFTS1

(negative impact)

22% 1% 0% 1% 2% 2% 1%

Reopened ML 1 roads (negative) 0% 0% 0% 0% 1% 0% 0%

Unauthorized routes where cross country travel 

is prohibited (positive impact)

0% 22% 22% 22% 21% 21% 22%

Cumulative effects of past, present, and proposed actions

Existing motorized routes - NFS lands (negative 

impact)

30% 30% 30% 30% 30% 30% 30%

Existing motorized routes - non-NFS lands 

(private) (negative impact)

15% 15% 15% 15% 15% 15% 15%

Existing non-motorized routes (negative impact)2

5% 5% 5% 5% 5% 5% 5%

Decommissioned routes (positive impact) 2% 2% 2% 2% 2% 2% 2%

Roads closed by previous NEPA decisions, 

pending implementation (positive impact)

1% 1% 1% 1% 1% 1% 1%

Total Cumulative Effects

Overall Relative Cumulative Impact Score = 

Sum Total of All Routes (negative impacts) 

(Note: Overlap occurs where route categories 

intersect, therefore percentages are only relative 

to each other and not actual amounts)

72% 51% 50% 51% 53% 52% 51%

1

Motorized Additions - Alternative 1 includes use on existing unauthorized routes associated with continued cross country travel

2

Non-motorized -assumption made that non-motorized impact is limited to 60 meters from trail and that no impact occurs beyond 60 

Cumulative Effects to Meadows from Past, Present and

Reasonably Foreseeable Actions

The cumulative effects geographic boundary for marten prey habitat includes 518 wet meadows occurring 

within the boundary of the Tahoe NF including NFS and non-NFS lands. This scale is sufficiently large to 

evaluate effects to microtine rodents that are important prey species for the marten. The cumulative 

effects timeframe is the same as stated for other species.

In some meadows, livestock grazing has reduced the suitability of meadow vegetation for microtine 

rodents and other marten prey (USDA Forest Service 2001). Livestock grazing occurs on 31 active 

grazing allotments on the Tahoe NF, totaling 538,431 acres of NFS and private lands. On the Tahoe NF, 

the impact of livestock grazing on meadows has been steadily decreasing as fewer allotments are grazed 

and as forage utilization levels are being reduced by stricter standards established by the Sierra Nevada 

Forest Plan Amendment. These past and present effects contribute to the effects of the alternatives upon 

meadow habitat and condition.

Cumulative Effects to Meadows

Cumulative effects are evaluated by assessing the number of wet meadows that are intersected by motorized 

route additions to the NFTS, motorized routes on existing NFS lands and non-NFS lands (private). In 
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Tahoe National Forest – 347

addition, non-motorized routes are also evaluated. Finally, the prohibition of cross country travel, including 

on existing unauthorized routes or decommissioned routes are also evaluated for their beneficial cumulative 

impacts where the adverse impacts of motorized routes would be removed are considered. 

Direct and indirect effects of adding motorized routes to the NFTS would add to existing cumulative 

effects to wet meadows which provide habitat for foraging marten and microtine rodents which are 

preferred marten prey species (Alternative 1 to the greatest extent, followed by Alternatives 5, 2, 3, 6, 4, and 

7, in decreasing order). Alternative 1 directly and indirectly affects 81 of 518 meadows (16% of all 

meadows) that would be impacted by continued cross country motorized use, including use of existing 

unauthorized routes. Considering existing cumulative effects from existing motorized routes on both public 

and private lands and non-motorized routes, this additional 16% of meadow impacts is substantial. In 

addition, since Alternative 1 does not prohibit public motor vehicle cross country travel on 9,167 acres of 

wet meadow habitat, which would continue and proliferate, and would result in cumulative impacts upon 

marten.

The remaining action alternatives would result in progressively fewer meadows being cumulatively 

impacted, with Alternative 5 contributing the most, to Alternative 3, which would not contribute to 

additional cumulative adverse impacts since no motorized routes are proposed. All the action alternatives 

benefit from the prohibition of cross country travel on 9,167 acres of wet meadow habitat, including on 

existing unauthorized routes, affecting between 78 and 81 meadows (15 to 16% of all meadows) where 

motorized vehicle use would be prohibited, as shown in Table 3.03-93. The overall cumulative effect as a 

result of cross country prohibitions, motorized route additions, and reopening ML 1 roads ranges from 

275 to 370 meadows intersected by routes (Alt 3 - the least, Alt 1 - the most).

Table 3.03-93. Cumulative Number of Wet Meadows Intersected by Routes

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Direct and Indirect effects of proposed alternatives

Wet Meadows Intersected by motorized route additions to the NFTS 

(negative impact)1 81 7 0 1 9 5 3

Wet Meadows Intersected by reopened ML 1 roads (negative impact) 0 0 0 0 2 0 0

Wet Meadows Intersected by existing unauthorized routes due to the 

prohibition of cross country travel (positive impact) 

1 78 82 81 76 78 80

Cumulative effects of past, present, and proposed actions

Wet Meadows Intersected by existing motorized routes - NFS lands 

(negative impact)

150 150 150 150 150 150 150

Wet Meadows Intersected by existing motorized routes on non-NFS 

lands (private) (negative impact)

96 96 96 96 96 96 96

Wet Meadows Intersected by existing non-motorized routes (negative 

impact)

2 39 39 39 39 39 39 39

Wet Meadows Intersected by decommissioned routes (positive impact) 11 11 11 11 11 11 11

Total Cumulative Effects

Overall Cumulative Effects equals the total of all impacts, both 

positive and negative

370 296 275 289 300 296 288

1

Motorized Additions - Alternative 1 includes use on existing unauthorized routes associated with continued cross country travel

2

Non-motorized -assumption made that non-motorized impact is limited to 60 meters from trail and that no impact occurs beyond 60 
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348 – Tahoe National Forest

Overall Cumulative Effects Summary

Appendix H (Reasonably Foreseeable Projects and Cumulative Effects) provides a list and description of 

past, present, and reasonably foreseeable vegetation and fuels management projects on NFS lands and 

private lands within the Tahoe NF boundary. Some, but not all, of these activities have contributed to 

effects on marten and have the potential to impact marten in the near future. In 2001 and 2004, the Forest 

Service amended Sierra Nevada Forest Plans to better address the needs of old forest-associated species 

(USDA Forest Service 2001 and 2004). In this assessment, the following key risk factors were identified 

for marten in the Sierra Nevada: (1) habitat alternation, particularly the removal of overhead cover, large 

diameter trees, or coarse woody material; (2) livestock grazing and other activities that might reduce the 

availability of prey in meadows; and (3) the use of roads and associated human access.

On the Tahoe NF, several activities have influenced these risk factors for marten. Wildfires occurring 

between 1990 and 2008 burned over 11,000 acres of suitable marten and fisher habitat (CWHR 4M, 4D, 

5M, 5D and 6), some of which was rendered unsuitable, and other areas maintained key habitat 

components. Past timber harvest and more recent fuels reduction treatments have reduced important 

habitat components in marten habitats. Between 2001 and 2008, fuels treatments on NFS lands have 

occurred on approximately 17,000 acres. These vegetation treatments have reduced habitat quality for 

marten and fisher by reducing canopy cover, structural complexity, and coarse woody material within 

treated units. At the larger landscape scale, these treatments may affect the size and connectivity of 

patches of high quality habitat. Over 30,000 acres of fuels and vegetation treatments are planned to occur 

over the next few years based upon the projects listed in Appendix H. Some, but not all of them would

affect marten and fisher habitat. Over time, fuels treatments are expected to alter 20 to 30 percent of the 

landscape, with a resulting expectation that the amount of habitat removed by stand replacing wildfires 

would be reduced in response to these treatments (USDA Forest Service 2004). 

The California Department of Forestry and Fire Protection currently lists approximately 12,000 acres

of private land within the Tahoe NF administrative boundary for which timber harvest plans have been 

submitted. The portion of these projects occurring within the marten’s range has not been determined. 

Timber harvest on private lands is generally more intensive and does not provide suitable habitat for 

marten and fisher.

Alternative 1 has the greatest likelihood of contributing to substantial adverse cumulative effects upon 

marten populations and may affect the ability to reestablish fisher over time. Alternatives 2, 4, 5, 6, and 7, 

would result cumulative effects to a lesser extent than Alternative 1. Alternative 3 results in the least 

cumulative effects because no motorized routes are proposed for addition to the NFTS; therefore, 

motorized route densities in marten habitat remain lowest, and motorized routes would not be added to 

the NFTS in habitats of particular importance to marten (meadows). The combined effects of the 

alternatives and other factors affecting marten and fisher habitats do not indicate that the magnitude of 

these combined effects would result in a loss of viability or lead to a trend toward Federal listing for the 

American marten under any alternative (see project Biological Evaluation). 

These alternatives do not result in a loss of habitat (no route construction), but may add to existing 

cumulative effects through reduced habitat effectiveness from the sum total of route additions, reopened 
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Tahoe National Forest – 349

ML1 road, and cross country travel prohibitions, where an additional 20 to 25% of marten habitat may be 

influenced by continued cross country travel, including continued use of existing unauthorized routes

under Alternative 1; about 5% under Alternative 5; and from 0 to 2% under the remaining action 

alternatives. The cumulative effects under Alternative 1, including fuels treatment and livestock grazing 

effects upon marten habitat, could be considerable. Inventoried Roadless Areas (IRAs) and adjacent 

wilderness areas may become increasingly important as the cumulative effect of fuels treatment activities 

expand within other portions of marten and fisher habitat.

Existing unauthorized routes, may receive non-motorized use (hiking, mountain bicycling, 

equestrian). It is generally considered that non-motorized use would be less impactive to fisher and 

marten due to reduced noise and other factors. The extent and magnitude of non-motorized use is 

unknown. However, it is expected that over time, these routes would eventually become revegetated and 

recover either through active or passive restoration means.

Sensitive Species Determination – American Marten

The Biological Evaluation for the Tahoe NF Motorized Travel Management Project, which is 

incorporated by reference, made a determination that all the action alternatives may affect individual 

American martens, but are not likely to result in a loss of viability or lead to a trend toward federal listing. 

Motorized routes through wet meadows are not proposed to be added to the NFTS in Alternative 6, the 

Preferred Alternative. Motorized routes within riparian conservation areas, including meadows would be

significantly reduced compared to Alternative 1, no action. Habitat fragmentation from motorized routes 

would be considerably reduced. Future route proliferation would be minimized due to prohibition of 

unmanaged cross country motorized travel. In addition, wet weather restrictions on native surfaced routes 

would reduce potential erosion and sedimentation within meadow habitat, important to marten prey 

species.

MIS Summary – American Marten

The American marten was selected as an MIS for late-seral closed canopy coniferous forest (ponderosa 

pine, Sierran mixed conifer, white fir, and red fir) habitat in the Sierra Nevada. This habitat is comprised 

primarily of medium/large trees (equal to or greater than 24 inches dbh) with canopy closures above 40% 

within ponderosa pine, Sierran mixed conifer, white fir, and red fir coniferous forests, and multi-layered 

trees within ponderosa pine and Sierran mixed conifer forests. Martens prefer coniferous forest habitat 

with large diameter trees and snags, large down logs, moderate-to-high canopy closure, and an 

interspersion of riparian areas and meadows. Important habitat attributes are: vegetative diversity, with 

predominately mature forest; snags; dispersal cover; and large woody debris (Allen 1987). Key 

components for westside and eastside marten habitat can be found in the Sierra Nevada Forest Plan 

Amendment FEIS (USDA Forest Service 2001), Volume 3, Chapter 3, part 4.4, pages 20-21. 

Based on the analysis conducted, Alternative 1 directly, indirectly, and cumulatively affects the 

greatest amount of late-seral closed canopy coniferous forest with a 200-meter Zone of Influence of 

existing motorized unauthorized routes, which would continue under continued cross country travel. 
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350 – Tahoe National Forest

Alternative 1 reduces habitat effectiveness by 8% (13,435 acres out of 167,938 Tahoe NF habitat acres), 

with the potential to disturb, cause avoidance, and abandonment of California spotted owl, American 

marten, and northern flying squirrel. Considering the checkerboard pattern of land ownership within the 

Tahoe NF boundary, Alternative 1 could cause a downward trend in habitat effectiveness for these 

species. In addition, the cross country travel would continue and proliferate on 119,091 acres of late-seral

closed canopy coniferous forest habitat.

Alternatives 2, 4, 5, and 6 would affect 1,679 acres of late-seral closed canopy coniferous forest 

habitat or 0.2% of Tahoe NF habitat within a 200-meter Zone of Influence of motorized route additions to 

the NFTS. Alternatives 3 and 7 do not affect late-seral closed canopy coniferous forest habitat within a 

200-meter Zone of Influence of motorized route additions. The Tahoe NF Motorized Travel Management 

Project action alternatives would not result in a direct or indirect change in the amount of late-seral closed 

canopy coniferous forest habitat affected by motorized routes for all the alternatives. Therefore, habitat 

effectiveness for these species would be maintained at current levels. 

For all the alternatives, the change in the class of vehicles would not directly, indirectly, or 

cumulatively affect late-seral closed canopy coniferous forest habitats or their habitat effectiveness. Wet 

weather seasonal restrictions on all native surfaced roads and motorized trails under Alternatives 4, 5, and 

6 would enhance late-seral closed canopy coniferous forest habitat effectiveness for the California spotted 

owl, American marten, and the northern flying squirrel through the reduced disturbance, avoidance, and 

abandonment. Finally, the prohibition of motorized cross country travel on 119,091 acres of late-seral

habitats, would benefit these species over time, thereby preventing the continued cumulative increase in 

motorized route proliferation in the future.

Summary of Status and Trend at the Bioregional Scale. The Tahoe NF LRMP (as amended by the 

SNF MIS Amendment) requires bioregional-scale habitat and distribution population monitoring for the 

American marten; hence, the late-seral closed canopy coniferous forest (ponderosa pine, Sierran mixed 

conifer, white fir, and red fir) habitat effects analysis for the Tahoe NF Motorized Travel Management 

Project must be informed by both habitat and distribution population monitoring data. The sections below 

summarize the habitat and distribution population status and trend data. This information is drawn from 

the detailed information on habitat and population trends in the SNF Bioregional MIS Report (USDA 

Forest Service 2008) and the Tahoe NF Motorized Travel Management Project-level MIS Report, which 

are hereby incorporated by reference.

Habitat Status and Trend. There are currently 994,000 acres of late-seral closed canopy coniferous 

forest (ponderosa pine, Sierran mixed conifer, white fir, and red fir) habitat on NFS lands in the Sierra 

Nevada. The trend is slightly increasing (from 7% to 9% within the last decade on NFS lands).

Population Status and Trend. American marten has been monitored throughout the Sierra Nevada 

as part of general surveys and studies from 1996-2002 (Zielinski et al. 2005). Since 2002, the American 

marten has been monitored on the Sierra Nevada forests as part of the Sierra Nevada Forest Plan 

Amendment (SNFPA) monitoring plan (USDA Forest Service 2005, 2006, 2007b). Current data at the 

range-wide, California, and Sierra Nevada scales indicate that, although marten appear to be distributed 

throughout their historic range, their distribution has become fragmented in the southern Cascades and
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Tahoe National Forest – 351

northern Sierra Nevada, particularly in Plumas County. The distribution appears to be continuous across 

high-elevation forests from Placer County south through the southern end of the Sierra Nevada. 

Relationship of Project-Level Habitat Impacts to Bioregional-Scale Trends. Based on the small 

proportion of late-seral closed canopy coniferous forest habitat that is directly, indirectly and cumulatively 

affected (0% to 1.4% of Sierra Nevada habitat) by the alternatives within a 200-meter Zone of Influence

of motorized route additions to the NFTS, the Tahoe NF Motorized Travel Management Project would not 

alter existing trend in the habitat, nor would it lead to a change in the distribution of American marten 

across the Sierra Nevada bioregion.

Pacific Fisher Sensitive Species Determination

Due to the absence of the Pacific fisher on the Tahoe NF, implementing the Tahoe NF Travel Management 

Project EIS would not affect the Pacific fisher (The Tahoe NF Biological Evaluation is incorporated by 

reference). Furthermore, this project as proposed would not likely affect any future reintroduction efforts 

and the ability for the fisher to become reestablished on the Tahoe NF since habitat fragmentation by the 

addition of motorized routes is minimized. Cross country motorized use would be prohibited, including 

use on existing unauthorized routes within suitable fisher habitat.

Compliance with Forest Plan and Other Direction

The Tahoe LRMP, as amended by the 2004 SNFPA ROD, provide the following management direction 

for meadow and wetland habitat:

• Locate roads away from meadow edges where alternative routes are available (Tahoe LRMP)

(Management Standard and Guideline).

• Avoid wetlands or minimize effects to natural flow patterns in wetlands and avoid road 

construction in meadows.

• Maintain and restore the hydrologic connectivity of streams, meadows, wetlands, and other special 

aquatic features by identifying roads and trails that intercept, divert, or disrupt natural surface 

and subsurface water flow paths. Implement corrective actions where necessary to restore 

connectivity (RCO#2, Management Standard & Guideline 100).

• Evaluate new proposed management activities within CARs and RCAs during environmental 

analysis to determine consistency with the riparian conservation objectives (RCOs) at the project 

level and the AMS goals for the landscape. Ensure that appropriate mitigation measures are 

enacted to (1) minimize the risk of activity-related sediment entering aquatic systems and (2) 

minimize impacts to habitat for aquatic- or riparian-dependent plant and animal species 

(Management Standard & Guideline 92).

Marten foraging habitat within wet meadow were analyzed for the alternatives. Based on the analysis 

of the alternatives, Alternative 1 least complies with this direction. Alternative 1 negatively affects 81 of 

518 meadows (16%) from cross country travel on 14 miles of existing unauthorized routes. The action 

alternatives all meet the Forest Plan Standards and Guidelines by reducing motorized impacts to meadows 

by prohibiting cross country travel, including on 13 to 14 miles of existing unauthorized routes. Of the 
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352 – Tahoe National Forest

action alternatives, Alternative 5 reduces the impacts on meadows the least and Alternative 3 reduces the 

impacts on meadows the most. 

The Tahoe LRMP, as amended by the 2004 SNFPA ROD provides management direction for the 

fisher and marten as follows:

Evaluate proposals for new roads, trails, off highway vehicle routes, and recreational and other 

developments for their potential to disturb den sites (Management Standard & Guidelines 87 and 

89).

Fisher have not been verified to occur on the Tahoe NF, and therefore this standard and guideline does 

not apply for fisher. However, marten does occur on the Tahoe NF, although known den sites have not 

been identified. The sections above thoroughly analyzes the alternatives for the potential to disturb 

suitable fisher and marten denning habitat (as defined by CWHR 4M, 4D, 5M, 5D, and 6 habitat types). 

The analysis of alternatives also analyzed the potential to disturb marten and fisher habitat within Old 

Forest Emphasis Areas and the Tahoe NF Carnivore Network, both of which provide important habitat 

attributes for these species.

Snags in Green Forest Ecosystem Component Associated Species: 

Affected Environment

Many wildlife species depend on snags or dead trees for nesting, roosting, denning, foraging, resting, or 

shelter. Snag associated species included in this group include both primary and secondary excavators. 

The hairy woodpecker is the species chosen to represent this group, although many other species are snag 

dependent species including other woodpecker species, pallid bat, and small songbirds such as nuthatches 

and chickadees. In addition, the hairy woodpecker was selected as the MIS on the Tahoe NF, as amended 

by the Sierra Nevada Forest Bioregion EIS, for the ecosystem component of snags in green forests. 

Medium to large (diameter breast height between 15 to 30 inches and greater than 30 inches) snags are 

most important. The hairy woodpecker uses stands of large, mature trees and snags of sparse to 

intermediate density; cover is also provided by tree cavities (CDFG 2005). Mature timber and dead snags 

or trees of moderate to large size are apparently more important than tree species (Siegel and DeSante 

1999).

Snags are the result of tree mortality that can result from insect outbreaks, diseases, fire, drought, and 

flooding. Such events maintain the snag resource through time, though snag numbers may fluctuate as 

forests undergo cycles of drought accompanied by higher tree mortality, followed by lower tree mortality 

after stands have thinned (Bull et al. 1997).

Habitat for snag associated species (cavity nesting birds and bats) is considered to be forested 

vegetation types with snags larger than 15 inches diameter. Table 3.03-3 lists the types of road and 

motorized trail-associated factors likely to affect Tahoe NF terrestrial species; one of these factors is the 

category listed as edge effects and the reduction of snags and down logs. Snag and log reduction occurs as 

result of managing roads or trails for public use. Trees posing a potential safety hazard (“hazard trees”) 

are removed along roads open for public use, as well as along roads receiving concentrated use during 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 353

implementation of a specific project. Hazard trees are typically dead or dying trees that occur within a 

tree-height distance from the road. This safety policy results in a reduction in snags within a zone of about 

60 meters from a road’s edge. This, in turn, reduces habitat quality and availability for snag associated 

species (i.e. cavity nesting birds and tree nesting bat species) within these roadside corridors. Studies have 

shown cavity-nesting birds to decline 53 to 77 percent after snag removal (Scott and Oldemeyer 1983, 

Raphael and White 1984, Hejl 1997).

The amount of down wood is also influenced within this zone, both by the removal of hazard trees 

that would become future down wood, and by the access provided for woodcutters. Down wood is 

important as a foraging substrate, providing insects required by species like the pileated woodpecker.

Nests of cavity nesting birds are typically more secure from nest predation than other forest birds, 

and recreational disturbance is not known to be a limiting factor as it is for some other forest bird species 

(Gaines et al. 2003). Roads and trails have the potential to adversely affect bats by facilitating access to 

bat habitats which may directly or indirectly affect bats.

Snags in Green Forest Ecosystem Component Associated Species: 

Environmental Consequences

Indicators used to Measure Effects

Zone of Influence within 60 Meters: For the proposed alternatives, the habitat factor used in this 

analysis to assess effects to medium (15-30 inches dbh) and large (greater than 30 inches dbh) snags 

within green forest, was the amount of green forest that fell within a 60-meter Zone of Influence of 

motorized routes added to the NFTS. A 60-meter Zone of Influence represents the proportion of snag 

habitat along motorized routes that may be affected by fuelwood or hazard tree removal, resulting in a 

reduction of snag habitat for the hairy woodpecker. This distance represents the maximum height of a 

snag that could be removed along proposed routes. 

The No Action Alternative (Alternative 1) was analyzed by determining the amount of green forest 

habitat that fell within a 60-meter Zone of Influence of existing unauthorized routes that could be affected 

by fuelwood.

Current Condition of the Habitat Factor(s) in the Project Area: On the Tahoe NF, snags in green 

forest ecosystem component vary in density, size, decay class, and distribution, depending upon the forest 

type, presence of decay factors (insects and diseases), and the amount of management activities that have 

taken place. Annual precipitation also affects the amount of snags present within green forests. Snag 

densities are generally higher in mixed conifer forests and true fir forests. Pure eastside pine forests 

generally have lower snag densities compared to forest types that have higher concentrations of true fir 

species (red fir and white fir). Snag densities on the Tahoe NF vary from 0 snags per acre to well over 6 

snags per acre.

Direct and Indirect Effects to Habitat

Cross Country Travel. Under Alternative 1, cross country travel would not be prohibited, potentially 

affecting 637,148 acres of green forest habitat, potentially causing reduced habitat effectiveness through 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

354 – Tahoe National Forest

disturbance, avoidance, and abandonment by the hairy woodpecker. For all action alternatives, cross 

country travel would be prohibited on these acres thus reducing or eliminating disturbance, avoidance, 

abandonment.

Additions to the NFTS and Reopened ML 1 Roads: Table 3.03-94 displays the alternatives affect 

hairy woodpecker habitat within a 60-meter Zone of Influence of motorized route additions to the NFTS

and reopened ML 1 roads, where snags could be removed for hazard tree removal or public fuelwood 

gathering. The Tahoe NF Motorized Travel Management Project could potentially directly or indirectly 

affect 1.5% (64,315 acres out of 4,381,000 Sierra Nevada habitat acres) of hairy woodpecker habitat

under Alternative 1, where incidental snags could be lost through public fuelwood removal, though it is 

not expected that this activity to be significant. 

All the action alternatives would reduce affects to hairy woodpecker habitat by banning cross country 

travel, including on existing unauthorized routes. Alternative 5 would affect 0.2% (7,076 acres of 

4,381,000 Sierra Nevada habitat acres) of hairy woodpecker habitat from both motorized route additions 

and reopened ML 1 roads, where each contributes about equal portion of the impacts. 

Alternatives 2, 4, and 7, similarly would affect 0.1% hairy woodpecker habitat (2,637 out of 

4,381,000 Sierra Nevada habitat acres), while Alternative 3 does not directly or indirectly affect hairy 

woodpecker habitat. It is not expected that all snags along motorized routes would be removed, but 

incidental removal of hazard trees for public safety and access to fuelwood gathering could result in the 

loss of incidental snags along proposed motorized route additions. The relatively small amount of habitat 

within a 60-meter Zone of Influence is not likely to result in a measurable change in the snag habitat 

component at the scale of the Sierra Nevada Bioregion.

Changes to NFTS (Wet Weather Seasonal Restrictions). Alternatives 4, 5, and 6 would impose wet 

weather seasonal restrictions on all native surfaced roads and motorized trails, where hairy woodpecker 

habitat effectiveness (snags within green forests) would be benefited through the reduced disturbance and 

avoidance when motorized use on native surfaced routes are restricted during the wet weather season. 

Alternatives 1, 2, 3, and 7 do not impose wet seasonal weather restrictions on native surfaced motorized 

routes and therefore, the hairy woodpecker habitat effectiveness would not be enhanced when native 

surfaced motorized routes are under wet weather seasonal restrictions. Under Alternative 1, continued 

cross country travel, including on existing unauthorized routes would result in the greatest amount of 

disturbance (reduced habitat effectiveness) to hairy woodpecker habitat within snags within green forests.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 355

Table 3.03-94. Cross Country Travel and Proportion of Snags in Green Forest Hairy Woodpecker habitat 

within a 60-meter “Zone of Influence” of Motorized Route Additions and Reopened ML 1 Roads to the NFTS

Hairy Woodpecker (Snags in Green 

Forest Habitat Ecosystem component)

Alt 11 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel within Tahoe NF project area

Acres of Hairy Woodpecker habitat 

where cross country travel is 

prohibited

0 637,148 637,148 637,148 637,148 637,148 637,148

Proportion of Snag Ecosystem Component in Green Forest Habitat (Hairy Woodpecker MIS Habitat)

within 60-meter “Zone of Influence”

Acres – Hairy 

Woodpecker 

Green Forest 

Habitat2 

Motorized route 

additions 64,315 2,512 0 1,214 3,347 2,950 1,335

Reopened ML 

Roads 0 0 0 0 3,729 0 0

Total 64,315 2,512 0 1,214 7,076 2,950 1,335

Proportion of Sierra 

Nevada Habitat (Based on 

total acres early, mid, lateopen canopy, and lateclosed canopy coniferous 

forests in SN bioregion)

4,381,000 1.5% 0.06% 0% 0.03% 0.16% 0.07% 0.03%

Habitat Security Risk in Sierra Nevada Low Low Low Low Low Low Low

Proportion of Tahoe NF 

Habitat

990,707 6.5% 0.3% 0% 0.1% 0.7% 0.3% 0.1%

Habitat Security Risk in Tahoe NF Low Low Low Low Low Low Low

1 Alternative 1 includes existing unauthorized routes that would continue with the continuance of cross country travel.

2 The Zone of Influence within 60 meters of motorized routes include both NFS and non-NFS lands within the boundary of the Tahoe 

NF due to the complex checkerboard ownership pattern. The proportion of habitat affected likely over-represents the actual amount 

of habitat affected on NFS lands.

Summary of Direct and Indirect Effects

Table 3.03-95 summarizes the overall net direct and indirect effect of the alternatives from motorized 

route additions, prohibition of cross country travel, wet weather restrictions, and changes in class of 

vehicles to the hairy woodpecker.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

356 – Tahoe National Forest

Table 3.03-95. Hairy Woodpecker - Summary of Overall Net Direct and Indirect Effects 

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres Cross Country Travel Prohibited 0 637,148 637,148 637,148 637,148 637,148 637,148

Motorized Route Additions*

Trend of Effect Negative Negative No Effect Negative Negative Negative Negative

Percent Habitat Affected within ZOI* 6.5% 0.3% 0% 0.1% 0.3% 0.3% 0.1%

Establishment of “Open Areas” No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Changes to 

NFTS

Change in Season of use No Effect No Effect No Effect Habitat 

effectiveness 

enhanced 

during 

seasonal 

restrictions

Habitat 

effectiveness 

enhanced 

during 

seasonal 

restrictions

Habitat 

effectiveness 

enhanced 

during 

seasonal 

restrictions

No Effect

Change in Class of Vehicles No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Reopened ML 

1 Roads

Trend of 

Effect 

No Effect No Effect No Effect No Effect Negative No Effect No Effect

Percent 

Habitat 

Affected 

within ZOI

0% 0% 0% 0% 0.4% 0% 0%

Amendments to Forest Plan No Effect No Effect No Effect No Effect No Effect No Effect No Effect
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 357

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres Cross Country Travel Prohibited 0 637,148 637,148 637,148 637,148 637,148 637,148

Motorized Route Additions*

Overall Net Effect of Proposed Actions Most 

impactive 

alternative 

from 

continued use 

on existing 

unauthorized 

routes (6.5% 

habitat 

affected in 

ZOI)

Cross country 

travel 

continued on 

637,148 

acres.

3rd most 

beneficial

alternative, 

shared with 

Alt 6 (0.3% 

habitat 

affected in 

ZOI). 

Cross country 

travel 

prohibited on 

637,148 

acres; 

although 

minor 

negative 

impacts from 

route 

additions; 

overall 

reduces 

disturbance 

and habitat 

fragmentation.

Benefits the 

most—does 

not add routes 

or reopen ML 1 

roads.

Cross country 

travel prohibited 

on 637,148 

habitat acres; 

reduces 

disturbance and 

habitat 

fragmentation.

2nd most 

beneficial

alternative, 

shared with Alt 

7 (0.1% habitat 

affected within 

ZOI)

Cross country 

travel prohibited 

on 637,148 

habitat acres; 

although minor 

negative 

impacts from 

route additions; 

overall reduces 

disturbance and 

habitat 

fragmentation.

Benefits the 

least (0.7% 

habitat 

affected in 

ZOI).

Cross country 

travel prohibited 

on 637,148 

habitat acres; 

although minor 

negative 

impacts from 

route additions 

and reopened 

ML 1 roads; 

overall reduces 

disturbance and 

habitat 

fragmentation.

3rd most 

beneficial

alternative, 

shared with Alt 

2 (0.3% habitat 

affected in 

ZOI).

Cross country 

travel prohibited 

on 637,148 

habitat acres.

although minor 

negative 

impacts from 

route additions; 

overall reduces 

disturbance and 

habitat 

fragmentation.

2nd most 

beneficial 

alternative, 

shared with Alt 

4 (0.1% habitat 

affected within 

ZOI).

cross country 

travel prohibited 

on 637,148 

habitat acres; 

although minor 

negative 

impacts from 

route additions; 

overall reduces 

disturbance and 

habitat 

fragmentation.

*Alternative 1 includes existing unauthorized routes that would continue with the continuance of cross country travel, while all the action alternatives include proposed route additions.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

358 – Tahoe National Forest

Cumulative Effects to Habitat in the Analysis Area

The spatial boundary for analyzing cumulative effects to the hairy woodpecker includes all medium (15 to 

30 inch dbh) and large snags (greater than 30 inch dbh) within green forests within the boundary of the 

Tahoe NF. Past and current cumulative effects to the medium and large snag ecosystem component 

include loss of snags through catastrophic wildfires; timber and fuels management; urban development 

and expansion within a highly checkerboard land ownership pattern; and public fuelwood removal. In 

addition, hazard tree removal along NFTS roads and recreational facilities has had an impact on the snag 

resource. Snag recruitment and creation from natural levels and unnaturally high levels of tree mortality 

has also been a factor in the condition of snags on the Tahoe NF. 

Appendix H (Reasonably Foreseeable Projects and Cumulative Effects) provides a list and 

description of past, present, and reasonably foreseeable projects on NFS and private lands within the 

Tahoe NF boundary. Some, but not all, of these activities would contribute to impacts to the late-seral

closed canopy coniferous forests within the Tahoe NF boundary. Since 1990, more than 130,000 acres of 

vegetation management activities have occurred on the Tahoe NF. Some, but not all, have resulted in 

impacts to snags in green forest habitats. Between 2001 and 2008, approximately 17,000 acres of forest 

vegetation and fuels projects were completed, which primarily thinned, masticated, and/or burned 

vegetation to reduce the potential for catastrophic wildfires. These treatments generally do not result in a 

reduction of snags in green forest habitat because they generally retain snags throughout the project areas 

as required by LRMP standards and guidelines. Between 1994 and 2008, approximately 95,000 acres 

burned on the Tahoe NF, some of which have resulted in the loss of hairy woodpecker habitat. Facilities 

maintenance through hazard tree removal along roads and near recreational facilities has resulted in a 

limited loss of snags.

Table 3.03-96 lists reasonably foreseeable future actions, including fuels, vegetation, recreation, nonmotorized trail development, and special use permit re-issuances.

Table 3.03-96. Direct, Indirect, and Cumulative Impact of Reasonably Foreseeable Future Projects

Project type Number of 

Projects

Direct and Indirect Impact Overall Cumulative Impact

Vegetation management/fuels 

reduction – thinning, group 

select, and aspen 

enhancement

~30 Loss of incidental snags for 

public safety and harvest 

operations.

Incidental loss of snags. 

Long-term beneficial cumulative 

effects by reduced risk of habitat 

loss from high severity wildfires.

Salvage harvest of burned 

forests

2 Short-term disturbance from 

harvest activities.

Loss of nesting and foraging 

habitat (snags), particularly in 

low to moderate burn areas.

Short term cumulative impact in 

localized areas, but overall snag 

retention requirements should 

offset any losses in habitat at the 

landscape scale..

Hazard tree removal 4 Potential loss of snags through 

hazard tree removal. Shortterm disturbance during 

harvest.

None to minimal cumulative 

impact

Special Use permit renewal 4 N/A administrative action None
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 359

Cumulative Effects Conclusion

The Tahoe NF Motorized Travel Management Project could potentially add to existing cumulative effects 

by directly or indirectly affecting approximately 6% (64,315 acres out of 990,707 Tahoe NF acres) of 

hairy woodpecker habitat, under Alternative 1, where snags could be removed for public safety along 

existing unauthorized routes. Alternative 5 affects approximately 1% (7,076 acres of 990,707 Tahoe NF 

acres) of hairy woodpecker habitat from motorized route additions and reopened ML 1 roads, each 

contributing about 50% of the impacts. Alternatives 2, 4, and 7, similarly affects 0.3% hairy woodpecker 

habitat, while Alternative 3 does not directly or indirectly affect hairy woodpecker habitat. Based on the 

small proportion of hairy woodpecker habitat potentially affected by the addition of motorized routes and 

reopened ML 1 roads, the Tahoe NF Motorized Travel Management Project would not alter the existing 

trend in the snags in green forest ecosystem component. 

The change is the class of vehicles would not affect or alter the condition of snags in green forest 

ecosystem component for the hairy woodpecker, but may result in higher snag densities along routes that 

receive different maintenance. 

Hairy woodpecker habitat effectiveness may be enhanced under Alternatives 4, 5, and 6 where wet 

weather seasonal restrictions on all native surfaced roads and motorized trails would be implemented. 

Alternatives 1, 2, 3, and 7 do not impose wet seasonal weather restrictions on native surfaced motorized 

routes and therefore, the hairy woodpecker habitat effectiveness would not be enhanced when native 

surfaced motorized routes are under wet weather seasonal restrictions. 

Under Alternative 1, cross country travel would continue, potentially affecting 637,148 acres of snags 

within green forest habitat, potentially causing reduced habitat effectiveness through disturbance, 

avoidance, and abandonment by the hairy woodpecker. For the action alternatives, cross country travel 

would be prohibited on 637,148 acres, where disturbance, avoidance, abandonment would be reduced or 

eliminated.

Summary of Hairy Woodpecker Status and Trend at the Bioregional Scale. The Tahoe NF LRMP 

(as amended by the SNF MIS Amendment) requires bioregional-scale habitat and distribution population 

monitoring for the hairy woodpecker; hence, the snag effects analysis for the Tahoe NF Motorized Travel 

Management Project must be informed by both habitat and distribution population monitoring data. The 

sections below summarize the habitat and distribution population status and trend data for the hairy 

woodpecker. This information is drawn from the detailed information on habitat and distribution 

population trends in the SNF Bioregional MIS Report (USDA Forest Service 2008), which is hereby 

incorporated by reference.

Ecosystem Component Status and Trend. The current (based on 2001-2004 inventory sources) 

average number of medium-sized and large-sized snags (> 15” dbh, all decay classes) per acre across 

major coniferous and hardwood forest types (westside mixed conifer, ponderosa pine, white fir, 

productive hardwoods, red fir, eastside pine) in the Sierra Nevada ranges from 1.4 per acre in eastside 

pine to 8.3 per acre in white fir. Detailed information by forest type, snag size, and snag decay class can 

be found in the SNF Bioregional MIS Report (USDA Forest Service 2008).
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

360 – Tahoe National Forest

Data from the mid-to-late 1990s were compared with the current data to calculate the trend in total 

snags per acre by Regional forest type for the 10 Sierra Nevada national forests and indicate that, during 

this period, snags per acre increased within westside mixed conifer (+0.80), white fir (+1.98), and red fir 

(+0.68) and decreased within ponderosa pine (-0.17), productive hardwoods (-0.17), and eastside pine (-

0.16).

Population Status and Trend. The hairy woodpecker has been monitored in the Sierra Nevada at 

various sample locations by avian point counts and breeding bird survey protocols, including 1997 to 

present – Lassen National Forest (Burnett and Humple 2003, Burnett et al. 2005); 2002 to present -

Plumas and Lassen National Forests (Sierra Nevada Research Center 2007); 1992 to 2005 – Sierra 

Nevada Monitoring Avian Productivity and Survivorship (MAPS) stations (Siegel and Kaschube 2007); 

and 1968 to present – BBS routes throughout the Sierra Nevada (Sauer et al. 2007). These data indicate 

that the hairy woodpecker continues to be present at these sample sites, and current data at the range wide, 

California, and Sierra Nevada scales indicate that the distribution of hairy woodpecker populations in the 

Sierra Nevada is stable.

Relationship of Project-Level Habitat Impacts to Bioregional-Scale Hairy Woodpecker Trend. 

Based on the small proportion of the snag ecosystem component in green forest that is directly, indirectly 

and cumulatively affected (0 to 1% of Sierra Nevada habitat) by the alternatives, the Tahoe NF Motorized 

Travel Management Project would not alter existing trend in the habitat, nor would it lead to a change is 

the distribution of hairy woodpecker across the Sierra Nevada bioregion.

Aquatic and Riparian Associated Species

Introduction: The Aquatic-Riparian group includes either terrestrial and aquatic species that spend a part 

or their entire life cycle within or adjacent to riparian and/or aquatic habitats. These include a large 

number of special status species on the Tahoe NF (Tables 3.03-1 and 3.03-2). This section will provide 

general information on road and trail-associated impacts to bald eagles, willow flycatchers, great gray 

owls, greater sandhill crane, frogs, fish, aquatic invertebrates, and general aquatic/riparian habitats that 

may be associated with this group. Species not included in detail here will be addressed in the Biological 

Evaluation and Management Indicator Species reports, which are hereby incorporated by reference. 

The effects of roads and motorized trails on aquatic habitat are considered to be wide-ranging and 

potentially serious at local levels. The Tahoe NF utilized the Ecosystem Management Decision Support 

(EMDS) system which utilizes knowledge-based decision support for determining relative risk of 

motorized travel routes to aquatic species and habitats. EMDS integrated geographic information system 

(GIS) data with knowledge-based reasoning and decision modeling technologies. Aquatic habitats include 

Riparian Conservation Areas associated with streams, ponds, lakes, meadows, and other riparian habitat. 

The analysis consisted of GIS and EMDS modeling outputs which included data on road density, 

proximity to streams, erosion hazard ratings, and stream crossings at multiple watershed scales (5th field, 

6th field, and 7th field). A detailed summary of the aquatic habitat modeling can be found in Chapter 3.02

(Watershed Resources: Geology, Soil, and Hydrology).
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 361

The indicators used to measure effects for aquatic and riparian species responds to the desired 

conditions and the management standards and guidelines for wetland, meadow, and aquatic systems as 

directed in the Tahoe LRMP, as amended by the SNFPA ROD (2004). See Analysis Framework: Statute, 

Regulation, Forest Plan, and Other Direction at the beginning of this Terrestrial and Aquatic Species 

section.

Riparian Associated Bird Species

Introduction

Under Executive Order 13186, migratory bird species are identified as a priority for planning efforts and 

for evaluating environmental effects of projects. In the Sierra Nevada bioregion, 53 species of birds 

depend critically on or substantially utilize riparian or meadow habitats (Siegel and DeSante 1999). Focal 

species associated with riparian habitats include the black-headed grosbeak, song sparrow, warbling vireo, 

Swainson’s thrush, tree swallow, Wilson’s warbler, and yellow warbler (RHJV 2004). These species are 

strongly associated with a range of riparian habitats on the Tahoe NF, from lower elevation streamside 

zones to higher elevation meadows.

Meadows provide some of the most important habitat for neotropical migrants and resident landbirds 

in the Sierra Nevada, providing important stopover habitat for many species (Siegel and DeSante 1999). 

Thirty-seven species critically depend on, or are strongly associated with Sierra montane meadows. Of 

these species, six are stable, 14 are decreasing, and four are increasing (13 are inadequately sampled by 

the BBS to allow the calculation of a population trend, but among these 13 are two California endangered 

species (willow flycatcher and great gray owl) and a California Bird Species of Special Concern (Vaux’s 

swift)). The preponderance of decreasing species is statistically significant. Riparian focal species that use 

meadow habitats include the song sparrow, yellow warbler, and Wilson’s warbler (RHJV 2004). Meadows 

also provide important habitat for the red-breasted sapsucker which is identified as a “Watch List” species 

in the Partners in Flight North American Landbird Conservation Plan.

Effects Common to All Riparian Bird Species

Changes in Class of Vehicles: Although responses to motorized vehicle use varies by species and 

depends upon the type of vehicle, in addition to the intensity, timing, speeds, and amount motorized 

vehicle use, specific species responses are not well understood. For this analysis, it is assumed that all 

vehicle types result in the same disturbance to riparian associated bird species. Therefore, changes in the 

class of vehicles would not vary in their direct effects to riparian associated bird species for all of the 

proposed alternatives. Indirect effects to riparian habitats are discussed under each species, as appropriate.

Wet weather seasonal restrictions: Alternatives 4, 5, and 6 would impose wet weather seasonal 

restrictions on all native surfaced roads and motorized trails where riparian species would benefit from 

reduced noise disturbance when wet weather restrictions would be implemented.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

362 – Tahoe National Forest

Bald Eagle: Affected Environment

On July 9, 2007, USDI Fish and Wildlife Service in a Final Rule announced that the bald eagle would be 

removed (delisted) from the Federal List of Endangered and Threatened Wildlife in the lower 48 states. 

Official delisting of the bald eagle occurred 30 days from the date the Final Rule. The bald eagle will 

continue to be protected by the Bald and Golden Eagle Protection Act and Migratory Bird Treaty Act. 

Upon delisting, the bald eagle was placed on the Regional Forester’s list of Sensitive Species. 

Bald eagles nest near or adjacent to large bodies of water. Within the Tahoe National Forest, twelve 

bald eagle breeding territories have been identified within the Tahoe NF boundary including NFS lands 

and private lands in recent years. Eight bald eagle territories with recent nesting activity are located on 

NFS lands. Four territories occur on private land at Donner Lake, Fordyce Lake, Spaulding Reservoir, and 

Milton Reservoir.

The road and motorized trail-associated factors that have been identified for the bald eagle include 

poaching, disturbance at specific site (nests and roost sites), and avoidance and displacement (Skagen et 

al. 1991, Stalmaster and Newman 1978). Several studies reported that eagles avoid or are adversely 

affected by human disturbance during the breeding period and may result in nest abandonment and 

reproductive failure (Stalmaster and Newman 1978, Andrew and Mosher 1982, Fraser 1985, Fraser et al. 

1985, Knight and Skagen 1987, Buehler et al. 1991, Grubb and King 1991, Grubb et al. 1992, Chandler et 

al. 1995, Grubb 1995, Mathisen 1968).

The response of bald eagles to human activities is variable. Individual bald eagles show different 

thresholds of tolerance for disturbance. The distance at which a disturbance causes bald eagles to modify 

their behavior also is affected by the sight distance of the motorized use. For example, forested habitat 

can reduce the noise generated by motorized activity. In addition, if the noise-generating activity is hidden 

from the nest site, disturbance thresholds may be reduced. Some studies report that bald eagles seem to be 

more sensitive to humans afoot than to vehicular traffic (Grubb and King 1991, Hamann 1999). Anthony 

et al. (1989) found that the mean productivity of bald eagle nests was negatively correlated with their 

proximity to main logging roads, and the most recently used nests were located in areas farther from all 

types of roads and recreational facilities when compared to older nests in the same territory. However, in 

2005 a bald eagle nest was discovered near a well-used County Road on the Tahoe NF to access a popular 

reservoir used for recreational activities including fishing and boating. Furthermore, other studies indicate 

bald eagles can tolerate a certain amount of human disturbance (Harmata and Oakleaf 1992 IN Gaines et 

al. 2003). Disturbance is most critical during: nest building, courtship, egg laying and incubation 

(Dietrich 1990). In general, recommended buffer distances to reduce potential disturbance to bald eagles 

during the breeding season have ranged from 300 to 800 meters (Anthony and Isaacs 1989, Fraser et al. 

1985, McGarigal 1988, Stalmaster 1987 In Joslin and Youmans 1999, Mathisen 1968). Grubb et al. 

(1992) found that eagles are disturbed by most activities that occur within 1500 feet (460 m); and they 

take flight when activities occur within 600 feet (180 m). Grubb and King (1991) assessed pedestrian 

traffic and vehicle traffic on bald eagle nesting activities and recommended buffers of 550 meters for 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 363

pedestrians and 450 meters for vehicles. The USDA Forest Service routinely institutes a Limited 

Operating Period for ground disturbing projects within 0.25 mile (400 meters) of bald eagle nest sites.

Nest site protection through area closures is one of the primary ways that the Forest Service has 

implemented measures to prevent the potential for bald eagle nest failure and/or abandonment due to 

human disturbances (USFWS 1986). There are currently two seasonal area closures for bald eagle nest 

site protection - one at Boca Reservoir and one at New Bullards Bar Reservoir.

In addition, roads and motorized trails have the potential to indirectly affect bald eagles by degrading 

water quality which may impact the distribution and abundance of fisheries upon which bald eagles prey.

Bald Eagle: Environmental Consequences

Indicators used to Measure Effects 

Cross Country Travel: The proliferation of routes associated with cross country travel can have an 

adverse impact to nesting bald eagles, and is analyzed for the alternatives at two scales within 400 meters 

(0.25 mi) and 800 meters (0.5 mi) of known nest sites.

Establishment of “Open Areas”: Motorized access across dry soils to shoreline of Boca, Stampede, 

and Prosser Reservoirs during low water is assessed to determine their impact to nesting bald eagles.

Disturbance at a Specific Site (Additions to the NFTS): Motorized route additions to the NFTS

within 1⁄4 mile and 1⁄2 mile of known bald eagle nest sites were determined to assess direct, indirect and 

cumulative effects.

Changes to the NFTS (Reopened ML 1 Roads and Wet Weather Seasonal Restrictions): Changes 

to the system within 1⁄4 mile and 1⁄2 mile of known bald eagle nest sites were determined to assess direct, 

indirect and cumulative effects.

Direct and Indirect Effects to Nesting Bald Eagles

Cross Country Travel. Cross country travel would be prohibited on 814 acres within 400 meters and on 

3,299 acres within 800 meters of bald eagle nest sites, for all the action alternatives. The prohibition of 

cross country travel would prevent the proliferation of new unauthorized routes and would reduce 

disturbance associated with motorized use on these routes within foraging and nesting habitat for bald 

eagles. The prohibition of cross country travel also results in a reduction of the total amount of roads and 

trails available for motorized use by preventing cross country motorized use, including use of the existing 

unauthorized routes in all the action alternatives. The prohibition of cross country travel would reduce the 

potential for disturbance to nesting bald eagles that may be vulnerable to activities associated with

motorized cross country travel. Alternative 1 does not prohibit cross country motorized use, and may 

result in increased disturbance to nesting bald eagles on between 814 acres and 3,299 acres.

Establishment of “Open Areas”: Motorized access to Boca, Stampede, and Prosser reservoirs would 

potentially affect three bald eagle nest territories under Alternatives 2 and 6, where motorized access to 

the shoreline below the high water mark is allowed when soils are dry. Bald eagle territories potentially 

affected by motorized access are located at Stampede Reservoir #2 (Sagehen Arm) and Prosser Reservoir. 

Although motorized access to the shoreline at Boca Reservoir is also proposed, there is currently a 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

364 – Tahoe National Forest

seasonal closure to protect bald eagles during the nesting season at this location. A second territory near 

Stampede Dam would not be affected by motorized access at Stampede Reservoir, since the nest site is 

located outside of the area where motorized access to the shoreline would be permitted.

Generally, low water conditions at these reservoirs occur during the latter part of the summer. 

However, the timing and duration of low water conditions occurring at Stampede Reservoir nest #2 and 

Prosser Reservoir will vary depending upon the yearly precipitation condition and upon the level of water 

drawn down. Reservoir water levels are regulated by the Bureau of Reclamation. Considerable water 

draw down levels can result during very dry years. Depending upon the timing and the actual water 

levels, overlap between the bald eagle nesting period (January through August) and motorized access may 

occur at Prosser and Stampede reservoirs. In general, overlap between motorized access and bald eagle 

nesting would likely occur toward the latter part of the bald eagle nesting season which could potentially 

cause nest disturbance and/or failure depending upon the timing when the activities overlap. However, the 

bald eagle nest territory at Prosser Reservoir was recently discovered and is located at the end of a wellused County Road. For Alternative 2, it is uncertain how providing motorized access to the shoreline 

during low water would impact nesting bald eagles at Stampede Reservoir nest #2 and Prosser Reservoir 

in the future because the nesting eagles may either become habituated to the motorized or may be subject 

to nest disturbance from increased use over time. Current levels of motorized use seem to be compatible 

with bald eagles nesting at Prosser Reservoir. However, if motorized and dispersed use increases in the 

future, this could potentially cause disturbance and ultimately loss in reproductive productivity for bald 

eagles at this site.

Table 3.03-97 displays how the alternatives would affect nesting bald eagles. Alternative 2 would 

result in establishing the most acres of “Open Areas” where disturbance to bald eagle could occur, 

especially on 12.8 acres within 0-400 meters of the Prosser Reservoir bald eagle nest site. Alternative 6 

proposes 5.4 acres of “Open Areas” within 0-400 meters, and therefore would have slightly less area 

where disturbance to bald eagles nesting at Prosser Reservoir would be likely to occur. Although, “Open 

Areas” are designated in the outer 400-800 meters from nest sites, the likelihood of motorized use in these 

“Open Areas” would not likely result in disturbance to eagles at this distance.

Alternatives 1, 3, 4, 5, and 7 would not propose “Open Areas” to access reservoirs, and therefore 

would have no effect to nesting eagles at Boca, Prosser, or Stampede reservoirs.

Table 3.03-97. Establishment of “Open Areas” to Access Reservoirs

Proposed “Open Areas” to Access Reservoirs Alt 1, 3, 4, 5, 7

(acres)

Alt 2

(acres)

Alt 6 

(acres)

Boca Reservoir Territory

Boca Reservoir. #7 (East Shore Boca) 0-400 meters 0 0 0

400-800 meters 0 4.8 4.8

Prosser Reservoir Territory

Prosser Reservoir 0-400 meters 0 7.4 0

400-800 meters 0 17.9 0
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 365

Proposed “Open Areas” to Access Reservoirs Alt 1, 3, 4, 5, 7

(acres)

Alt 2

(acres)

Alt 6 

(acres)

Prosser Reservoir #1 (Boat Launching) 0-400 meters 0 5.4 5.4

400-800 meters 0 0 0

Prosser Reservoir #2 (Dam View) 0-400 meters 0 0 0

400-800 meters 0 1.0 1.0

Prosser Reservoir #12 0-400 meters 0 0 0

400-800 meters 0 7.8 7.8

Stampede Reservoir Territory

Stampede Reservoir 0-400 meters 0 0 0

400-800 meters 0 20.0 0

Stampede Reservoir #8 (South 

Stampede Cove)

0-400 meters 0 0 0

400-800 meters 0 17.1 17.1

Total Acres of “Open Areas”

0-400 meters 0 12.8 5.4

400-800 meters 0 68.6 30.7

Total Acres (0-800 meters) 0 81.4 36.1

Disturbance at a Specific Site (Additions to the NFTS)

Disturbance to bald eagle nest sites from alternatives is analyzed by determining the number of miles of 

motorized routes added to the NFTS occurring between 0 and 400 meters, and between 400 and 800 

meters from each bald eagle territory (Table 3.03-98). Factors associated with motorized routes at a 

distance between 0 to 400 meters of bald eagle nest sites will likely cause the greatest potential 

disturbance to nesting bald eagles during the nesting season. Disturbance from motorized routes between 

400 and 800 meters away from nest sites will likely have a lesser effect since noise associated with 

vehicles diminishes at greater distances, but may still modify behavior of nesting eagles, particularly for 

foraging eagles.

Table 3.03-98 indicates that Alternative 1 poses the greatest risk to nesting bald eagles on the Tahoe 

NF. Alternative 1 would potentially impact 7 bald eagle territories where continued cross country travel 

would result in continued use on 3 miles of existing unauthorized routes within 400 meters of bald eagle 

nest sites. An additional 6 miles would potentially affect bald eagle nest sites between 400 and 800 

meters. Territories at Deer Creek, Boca Reservoir, Prosser, and Webber Lake would receive the greatest 

potential for disturbance associated with motorized use on unauthorized routes totaling between 1⁄2 to 1 

mile per territory that are located less than 400 meters of a nest site. Roads within close proximity to bald 

eagle nest sites have the highest likelihood to disturb and disrupt nesting eagles.

All the action alternatives would benefit bald eagle by prohibiting cross country travel on existing 

unauthorized routes that are in close proximity to nest sites. None of the action alternatives proposes to 

add any routes to the NFTS within 400 meters of nest sites.

Two of the bald eagle territories (Stampede Dam and Milton) have proposed route additions that are 

located within the 400 to 800 meter analysis area for bald eagle nest sites. Proposed route TKN-J9
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

366 – Tahoe National Forest

(Alternatives 2, 4, 5, 6, and 7) is located nearly 800 meters from the Stampede Dam nest site. This route 

should not pose a concern to nesting eagles at Stampede Dam, since the area is forested and the route is 

not visible from the nest site. Alternative 6 proposes to add route “D_SIE-0301_d,” which is a very short 

spur (0.01 mile) that accesses a dispersed recreation site. Route “D_SIE-0301_d” also is located nearly 

800 meters away from the known Milton nest site, and should not pose a concern to nesting eagles at 

Milton.

Table 3.03-98. Miles of Motorized Routes added to the NFTS within 0 to 400 meters and within 400 to 800

meters of Bald Eagle Nest Site

Route ID Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Deer Creek Territory

0 to 400 meters Unauthorized routes 0.4 0 0 0 0 0 0

400 to 800 meters Unauthorized routes 1.5 0 0 0 0 0 0

Stampede Dam Territory

0 to 400 meters Unauthorized routes 0.1 0 0 0 0 0 0

400 to 800 meters Unauthorized routes (Alt 1), 

TKN-J9 (Alt 2, 4, 5, 6, 7)

1.3 0.1 0 0.1 0.1 0.1 0.1

Stampede at Sagehen Arm Territory

0 to 400 meters Unauthorized routes 0.1 0 0 0 0 0 0

400 to 800 meters Unauthorized routes 0.7 0 0 0 0 0 0

Boca Reservoir Territory

0 to 400 meters Unauthorized routes 0.9 0 0 0 0 0 0

400 to 800 meters Unauthorized routes 0.8 0 0 0 0 0 0

Prosser Reservoir Territory

0 to 400 meters Unauthorized routes 1.1 0 0 0 0 0 0

400 to 800 meters Unauthorized routes 0.9 0 0 0 0 0 0

Webber Lake

0 to 400 meters Unauthorized routes 0.4 0 0 0 0 0 0

400 to 800 meters Unauthorized routes 0.8 0 0 0 0 0 0

Milton Reservoir Territory (private)

0 to 400 meters None 0 0 0 0 0 0 0

400 to 800 meters D_SIE-0301_d 0.2 0 0 0 0 0.01 0

Total Motorized Route Additions For All Nest Sites

0 to 400 meters 3.1 0 0 0 0 0 0

400 to 800 meters 6.2 0.1 0 0.1 0.1 .11 0.1

Total (0 to 800 meters) 9.3 0.1 0 0.1 0.1 0.1 0.1

*Alternative 1 includes existing unauthorized routes that would continue under cross country travel

Changes to the NFTS

Wet Weather Seasonal Restrictions. Under Alternatives 4, 5, and 6, when wet weather restrictions on all 

native surfaced roads and motorized trails overlap with critical bald eagle nesting periods (overlap 

January – March), bald eagle would benefit from reduced noise disturbance associated with motorized 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 367

use. The remaining alternatives do not impose wet weather restrictions, and therefore would not benefit 

bald eagle during critical nesting periods. 

Reopened ML 1 Roads. None of the alternatives proposes to reopen any ML 1 Roads in bald eagle

habitat, therefore, no effects to bald eagle would occur from reopening closed ML 1 Roads.

Summary of Direct and Indirect Effects

Table 3.03-99 summarizes the overall net direct and indirect effect of the alternatives from motorized 

route additions to the NFTS, prohibition of cross country travel, wet weather restrictions, and changes in 

class of vehicles.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

368 – Tahoe National Forest

Table 3.03-99. Bald Eagle - Summary of Overall Net Direct and Indirect Effects

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

400 meters of 

nests

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres Cross Country 

Travel Prohibited

0 814 acres 814 acres 814 acres 814 acres 814 acres 814 acres

800 meters of 

nests

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres Cross Country 

travel Prohibited

0 3,299 acres 3,299 acres 3,299 acres 3,299 ac 3,299 ac 3,299 acres

Motorized Route Additions to NFTS

400 meters of 

nests

Trend of Effect Negative No Effect No Effect No Effect No Effect No Effect No Effect

Miles 3.1 0 0 0 0 0 0

800 meters of 

nests

Trend of Effect Negative Negligible 

Effect

No Effect Negligible 

Effect

Negligible Effect Negligible 

Effect

Negligible 

Effect

Miles 9.3 0.07 0 0.07 0.07 0.08 0.07

Establishment of “Open Areas”

Acres Trend of Effect N/A Negative, 2nd

most impactive

No Effect No Effect No Effect Negative, 3rd most 

impactive

No Effect

0-400 meters of 

nests

N/A 12.8 0 0 0 5.4 0

400-800 meters of 

nests

N/A 68.6 0 0 0 30.7 0

Changes to 

the NFTS

Wet Weather 

Restrictions

No effect No effect No effect Beneficial -

reduced 

disturbance 

during nesting 

season.

Beneficial -

reduced 

disturbance 

during nesting 

season.

Beneficial -

reduced 

disturbance 

during nesting 

season.

No effect

Change in Class of 

Vehicles

No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Reopened ML 1 

Roads

No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Amendments to Forest Plan No Effect No Effect No Effect No Effect No Effect No Effect No Effect
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 369

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Overall Net Effect of Proposed Actions

Cross Country Travel Negative 

impacts primarily 

from continued 

cross country 

travel, on 814 to 

3,299 acres 

Benefits from 

reduced nesting 

disturbance as 

a result of cross 

country travel 

prohibited on 

814 to 3,299 

acres. 

Benefits most 

from reduced 

nesting 

disturbance as 

a result of cross 

country 

prohibited travel 

on 814 to 3,299 

acres. 

Benefits from 

reduced nesting 

disturbance as a 

result of cross 

country 

prohibited travel 

on 814 to 3,299 

Benefits from 

reduced nesting 

disturbance as a 

result of cross 

country 

prohibited travel 

on 814 to 3,299 

acres 

Benefits from 

reduced nesting 

disturbance as a 

result of cross 

country 

prohibited travel 

on 814 to 3,299 

acres 

Benefits from 

reduced nesting 

disturbance as 

a result of cross 

country 

prohibited travel 

on 814 to 3,299 

acres

Motorized Route Additions Adverse effect of 

continued cross 

country travel on 

3 miles of 

unauthorized 

routes within 

close proximity 

to nest sites

Negligible effect 

of 0.1 mile 

added within 

outer 800 meter 

radius of nest 

affecting 1 nest 

site.

No routes 

added

Negligible effect 

of 0.1 mile added 

within outer 800 

meter radius of 

nest affecting 1 

nest site

Negligible effect 

of 0.1 mile added 

within outer 800 

meter radius of 

nest affecting 1 

nest site

Negligible effect 

of 0.1 mile added 

within outer 800 

meter radius of 

nest affecting 2 

nest sites

Negligible effect 

of 0.1 mile 

added within 

outer 800 meter 

radius of nest 

affecting 1 nest 

site

Wet Weather Restrictions Negative Effects 

from season 

long motorized 

use

Negative 

Effects from 

season long 

motorized use

Negative 

Effects from 

season long 

motorized use

Reduced 

disturbance from 

wet weather 

restrictions

Reduced 

disturbance from 

wet weather 

restrictions

Reduced 

disturbance from 

wet weather 

restrictions

Negative 

Effects from 

season long 

use

*Alternative 1 includes existing unauthorized routes that would continue with the continuance of cross country travel, while all the action alternatives include proposed route additions.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

370 – Tahoe National Forest

Cumulative Effects to Nesting Bald Eagles

Cumulative effects to the bald eagle include the cumulative effects of all motorized routes occurring on 

NFS and private lands within the Tahoe NF. 

Cumulative Effects Boundary

Bald eagle cumulative effects include all the bald eagle nest territories and surrounding bald eagle habitat 

that occur within the boundary of the Tahoe NF including both NFS lands and private lands. This 

geographic boundary is sufficient large enough to analyze cumulative effects to bald eagles since their 

home ranges lie entirely within the boundary of the Tahoe NF. The spatial timeframe for analyzing 

cumulative effects goes back approximately 50-100 years into the past and approximately 20 to 50 years 

into the future.

Cumulative Effects Summary of Past, Present, and Reasonably Foreseeable Actions

The development of reservoirs across the Forest on both NFS and non-NFS lands have created bald eagle 

foraging habitat. Cumulative effects to the bald eagle habitat around these reservoirs include disturbance 

from a variety recreational activities including developed and dispersed camping, hiking, fishing, boating, 

motorized vehicle use, and others. Seasonal closures at Boca and Bullards Bar reservoirs have been 

instituted to mitigate potential adverse recreational disturbance to nesting bald eagles. Bald eagles appear 

to be able to adapt to a certain amount of human disturbance and appear to be increasing on the Forest. 

Historic vegetation management activities have removed a considerable amount of bald eagle nesting 

habitat particularly on the east side of the Forest around Boca, Stampede and Prosser Reservoirs (i.e. large 

diameter trees used for nesting). The loss of nesting and foraging habitat from high levels of disease and 

drought related bark beetle infestations have also affected the quality and quantity of bald eagle habitat. 

Present and future fuels and vegetation management prescriptions are designed to retain the larger tree 

component, so that bald eagle nest tree components should be available. In addition, large snags used for 

roost trees would also be retained. Forest thinning and fuels treatment projects are designed to prevent 

loss of bald eagle habitat over the long-term.

Miles of Motorized Routes within 0 to 400 Meters of Nest Sites

The direct and indirect effects of the alternatives contribute to two of the four risk factors described above 

- degradation of wintering or breeding habitat through human development or habitat alteration, and 

disturbance at nest and roost sites. 

Under Alternative 1, cross country travel would continue, including travel on approximately 3 miles 

of existing unauthorized routes within 400 meters of a bald eagle nest site, which would potentially result 

in direct disturbance to nesting bald eagles (Table 3.03-100). In addition, under Alternative 1, wet weather 

closures would not be proposed on native surfaced roads and motorized trail, and could result in decreases 

in water quality of bald eagle foraging habitat. Because Alternative 1 does not prohibit motor vehicle 

cross country travel, it is highly likely that future route proliferation and associated cumulative impacts 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 371

would likely increase, and therefore the effects of Alternative 1, when combined with the effects of 

current and future recreation, may result in significant adverse cumulative effects to nesting bald eagles.

None of the action alternatives would result in direct or indirect effects to known nest sites within 400 

meters from the addition of routes to the NFTS or reopening of ML 1 roads, and therefore they do not 

contribute to existing cumulative impacts. In addition, alternatives 4, 5, 6 provide some added benefit to 

bald eagle foraging habitat from wet weather seasonal closures.

For all the action alternatives, future cross country motorized travel would be prohibited, including 

motorize use on approximately 3 miles of existing unauthorized routes within 400 meters of nest sites. 

Cross country travel on 814 acres within 400 meters of bald eagle nest sites would benefit bald eagles by 

preventing direct disturbance to nesting bald eagles on the Tahoe NF. However, non-motorized use 

(hiking, mountain bicycling, equestrian, etc.) may occur on these routes. Some impacts to bald eagles may 

be expected from non-motorized use in the future, but may be less or more than motorized use depending 

on the type and intensity of disturbance. Bald eagle response to non-motorized disturbance also depends 

upon any individual bald eagle’s ability to become habituated to certain types of disturbance. 

Furthermore, as these existing unauthorized routes become re-vegetated and recover either through active 

or passive restoration efforts, overall bald eagle disturbance from human activity is expected to diminish 

in the future.

Table 3.03-100. Cumulative Effects of Motorized Routes within 0 to 400 meters of Bald Eagle Nest Sites

Miles Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Direct and Indirect effects of proposed alternatives

Motorized route additions to the NFTS 0 0 0 0 0 0 0

Unauthorized routes with continued cross country travel

(negative impact)1 3.1 0 0 0 0 0 0

Reopened ML 1 Roads 0 0 0 0 0 0 0

Existing unauthorized routes prohibited to cross country travel 

(positive impact)

0 3.1 3.1 3.1 3.1 3.1 3.1

Cumulative effects of past, present, and proposed actions

Existing motorized routes - NFS lands (negative impact) 0.9 0.9 0.9 0.9 0.9 0.9 0.9

Existing motorized routes on private land - non-NFS lands 

(negative impact) 0.8 0.8 0.8 0.8 0.8 0.8 0.8

Existing non-motorized routes (negative impact) 0 0 0 0 0 0 0

Decommissioned and Closed ML 1 Roads (positive impact) 0.8 0.8 0.8 0.8 0.8 0.8 0.8

Net Cumulative Effects

Overall Cumulative Effects equals the total of all impacts, 

both positive and negative 5.6 1.7 1.7 1.7 1.7 1.7 1.7

1

Alternative 1 includes existing unauthorized routes that would continue with the continuance of cross country travel.

Table 3.03-101 displays the number of route miles which may contribute to disturbance to nesting 

eagles between 400 and 800 meters, though probably to a lesser extent than routes within closer proximity 

to nest sites (i.e. routes less than 400 meters). Motorized routes beyond 400 meters of nest sites, 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

372 – Tahoe National Forest

potentially can add to existing cumulative impacts to bald eagle nesting success. As stated earlier, some 

studies have shown that eagles responded to disturbance at distances less than 800 meters.

Table 3.03-101 Cumulative Effects of Motorized Route miles within 400 to 800 meters of Bald Eagle Nest Sites

Miles Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 

7

Direct and Indirect effects of proposed alternatives

Motorized Route additions to the NFTS (negative impact)1 9.3 0.1 0 0.1 0.1 0.1 0.1

Reopened ML 1 roads 0 0 0 0 0 0 0

Unauthorized routes prohibited to cross country travel (positive 

impact)

0 9.2 9.3 9.2 9.2 9.2 9.2

Cumulative effects of past, present, and proposed actions

Existing motorized routes - NFS lands (negative impact) 9.0 9.0 9.0 9.0 9.0 9.0 9.0

Existing motorized routes on private land - non-NFS lands 

(negative impact)

4.7 4.7 4.7 4.7 4.7 4.7 4.7

Existing non-motorized routes (negative impact) 0.0 0.0 0.0 0.0 0.0 0.0 0.0

Decommissioned and closed ML 1 roads (positive impact) 1.8 0.4 0.4 0.4 0.4 0.4 0.4

Total Cumulative Effects

Overall cumulative effects equals the total of all impacts, 

both positive and negative

23.0 13.8 13.7 13.8 13.8 13.8 13.8

1

Alternative 1 includes existing unauthorized routes that would continue with the continuance of cross country travel.

Sensitive Species Determination 

The Biological Evaluation for the Tahoe NF Motorized Travel Management Project, which is hereby 

incorporated by reference, made a determination that the action alternatives may affect the bald eagle, but 

do lead to a trend toward federal listing or loss of viability within the Tahoe NF, since current and future 

cross country travel by motorized vehicles would be prohibited. The prohibition of cross country travel 

would reduce the potential for disturbance to nesting bald eagles that may be vulnerable to activities 

associated with motorized use and cross country travel. Alternative 1, no action, may affect individual 

bald eagles and may lead to a trend toward federal listing due to the continued route proliferation from 

cross country motorized travel. Alternative 1 does not prohibit cross country motorized use, and may 

result in increased disturbance to nesting bald eagles.

Willow Flycatcher: Affected Environment

On the Tahoe NF, the willow flycatcher (Empidonax traillii ssp. trailii and E.t. brewsteri) is designated by 

the Regional Forester as a Sensitive species. In California, the willow flycatcher is a rare to locally 

uncommon, summer resident in wet meadow and montane riparian habitats at 600-2500 m (2000-8000 ft) 

in the Sierra Nevada and Cascade Range (CWHR 2005). Willow flycatcher populations in the Sierra 

Nevada are considered to be at risk (USDA Forest Service 2001). Historically, willow flycatchers were 

once common throughout the Sierra Nevada. The current distribution of the willow flycatcher has been

drastically reduced compared to historic distributions. A ten year demographic analysis indicates the 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 373

Sierra Nevada willow flycatcher populations are continuing to decline. With the exception of a few sites, 

the majority of areas where willow flycatchers have been located support low numbers of breeding 

territories, and some as low as 1-2 pairs of breeding individuals.

Willow flycatcher breeding habitat is characterized as montane wetland shrub habitat where there is a 

prevalence of willows and montane meadows with standing or flowing water, or highly saturated soils 

throughout the nesting season (Green, et al. 2003). A study by Cain (2001 In Cain et al 2003) indicated 

that meadow wetness may assist in successful nesting by willow flycatcher by inhibiting potential forest 

and edge predators from accessing willow flycatcher nests. Meadow wetness may also be important for 

willow flycatcher insect prey species.

The Willow Flycatcher Conservation Assessment (Green et al. 2003) identified roads as one of the 

leading contributing factors responsible for the loss and degradation of willow flycatcher habitat. 

Specifically, roads (dirt-surfaced or paved), intercept surface and subsurface hydrological flow. Meadow 

desiccation occurs when hydrological flows are intercepted and redirected which may result in long-term 

habitat loss or degradation. Roads may have a negative impact on meadow hydrology, especially when 

roads bisect meadows and have associated drainage structures to maintain road conditions. Human 

disturbance associated with road and trail motorized use may also affect willow flycatcher nesting 

success. Roads also provide increased access to humans which may directly and indirectly affect willow 

flycatcher productivity. Roads provide access for livestock grazing and often meadows occupied by 

willow flycatchers are key forage areas for livestock. 

Livestock grazing has long been identified as contributing to the decline in willow flycatcher 

populations as it relates to grazing impacts on willow and meadow habitat, as well as potential direct 

impacts from cattle coming in direct contact or destroying nest sites. Furthermore, brown-headed 

cowbirds are strongly associated with cattle. Cowbirds are known to parasitize willow flycatcher nests 

and ultimately may reduce overall willow flycatcher nesting success. 

At least two willow flycatcher breeding sites have received damage from off road vehicle travel on 

the Tahoe NF in recent years. Wheel tracks leaving ruts within one willow flycatcher meadow was 

observed on more than one occasion. Several grazing allotments on the Tahoe NF overlap occupied and 

emphasis willow flycatcher sites.

Willow Flycatcher: Environmental Consequences

Indicators used to Measure Effects

Cross Country Travel: The prohibition of cross country travel is analyzed for their effects to willow 

flycatcher occupied and emphasis habitat.

Additions to the NFTS (Number of Occupied and Emphasis Willow Flycatcher Sites): To 

evaluate the effects of motorized route additions to the NFTS on willow flycatcher habitat, the number of 

willow flycatcher Occupied and Emphasis meadow sites containing motorized route additions to the 

NFTS is determined. The Sierra Nevada Framework Plan Amendment ROD (2004) designated Occupied 

and Emphasis Habitats for willow flycatcher. Occupied habitats are sites where willow flycatcher(s) have 

been detected during the breeding season (between 15 June and August 1) (See SNFPA ROD 2004 for 
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374 – Tahoe National Forest

more detailed definition). Emphasis habitat is defined as meadows within 5 miles of Occupied willow 

flycatcher sites that are larger than 15 acres that have standing water on June 1 and a deciduous shrub 

component.

Establishment of “Open Areas”: “Open Areas” are analyzed to assess the effects on willow 

flycatcher occupied and emphasis meadow habitats.

Changes to the NFTS

Change in Class of Vehicles: The changes in class of vehicle was analyzed for their potential to affect 

willow flycatcher occupied and emphasis habitat, since this action potentially changes the condition of the 

existing road surface from smoothed surfaced to rough surfaced; which could potentially alter meadow 

condition where routes intersect meadows or are within close proximity to motorized routes.

Wet weather seasonal restrictions: Wet weather seasonal restrictions on native surfaced roads and 

motorized trails are analyzed for their potential to benefit willow flycatcher habitat through the reduction 

of erosion and sedimentation that could occur from wet season motorized use for each of the alternatives. 

Reopened ML 1 road: Reopened ML 1 roads are analyzed to assess the effects on willow flycatcher 

habitat, similar to how effects are analyzed for motorized route additions. 

Direct and Indirect Effects

Cross Country Travel

Alternative 1 would pose the greatest risk to willow flycatcher on 3,075 acres (occupied meadows - 1,747 

acres, emphasis meadows - 1,328 acres where willow flycatcher meadows would be subject to continued 

cross country travel, including on existing unauthorized routes. 

Table 3.03-102 indicates the willow flycatcher occupied and emphasis meadows that would be 

prohibited to cross country travel that are currently intersected by unauthorized routes. Under Alternative 

1, cross country travel would continue, potentially causing disturbance to willow flycatcher and habitat 

degradation.

Under the action alternatives, motorized cross country travel would be prohibited on 1,747 acres 

willow flycatcher occupied meadows, and on 1,328 acres emphasis meadows, totaling 3,075 acres willow 

flycatcher meadows, including on approximately 4 miles of existing unauthorized routes within 19 to 22 

willow flycatcher meadows. Under the action alternatives, active or passive restoration within these 

meadow sites would benefit willow flycatchers in terms of nesting, foraging, and future reestablishment 

opportunities.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 375

Table 3.03-102. Willow flycatcher sites with unauthorized routes, prohibited to cross country travel

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Number of Occupied Meadows with unauthorized 

routes prohibited to cross country travel 

0 4 4 4 4 4 4

Miles Unauthorized Routes in Occupied Meadows 

prohibited to cross country travel 

0 1.16 1.16 1.16 1.16 1.16 1.16

Number Emphasis Meadows with unauthorized 

routes prohibited to cross country travel

0 17 18 16 16 15 18

Miles Unauthorized Routes in Emphasis Meadows

prohibited to cross country travel 

0 2.70 2.84 2.69 2.57 2.67 2.72

Total Occupied and Emphasis Meadows 0 20 22 21 18 17 21

Total Miles in Occupied and Emphasis Meadows 

Prohibited to Cross Country Travel

0 3.86 4.0 3.85 3.73 3.83 3.88

Establish “Open Areas” - Greenhorn and Reservoir Areas

Establishing “Open Areas” at Greenhorn, and at Boca, Stampede, and Prosser reservoirs would have no 

direct or indirect effect to Occupied and Emphasis meadow habitat for the willow flycatcher. No willow 

flycatcher habitat occurs within the proposed “Open Areas.”

Additions to the NFTS

Direct and indirect effects of the alternatives are evaluated by determining the number of proposed 

motorized route additions to the NFTS that intersect delineated willow flycatcher meadow meadows on 

the Tahoe NF.

Number of Occupied and Emphasis Willow Flycatcher Meadows: Table 3.03-103 displays the 

willow flycatcher Occupied and Emphasis meadow sites on the Tahoe NF that are potentially affected by 

the alternatives. Under Alternative 1, 22 of 60 (37%) willow flycatcher meadow sites would be 

intersected by existing unauthorized routes (4.1 miles), which would continue to receive motorized use 

associated with cross country travel, where direct and indirect disturbance could occur. 

Of these sites, 4 out of 19 meadows (21%) identified as Occupied willow flycatcher sites, including 

approximately 1.2 miles of existing unauthorized routes have the potential to adversely affect breeding 

willow flycatchers, including both direct disturbance to nesting willow flycatchers and indirect impacts to 

willow flycatcher habitat through alteration and/or habitat degradation where routes potentially affect 

meadow vegetation and hydrology.

Alternatives 2, 3, 4, 5, 6, and 7 do not propose motorized route additions to the NFTS within 

Occupied willow flycatcher habitat where willow flycatchers are known to breed. Therefore, direct and 

indirect impacts to breeding willow flycatchers under these alternatives are not expected to occur.

Of the action alternatives, Alternative 6 would affect the most Emphasis meadows, totaling just under 

0.2 mile, primarily from motorized route additions which access dispersed recreation areas (6 out of 7 

routes). Most of these routes which access dispersed sites are very short segments totaling less than 0.01 

mile (Table 3.03-103). The ability for willow flycatcher to occupy these emphasis meadows that are 

potentially affected by the action alternatives is unknown. However, professional judgment would 
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376 – Tahoe National Forest

indicate that these meadows may not actually meet suitability criteria for willow flycatcher occupancy, 

which is dependent on many factors, including nearby meadows that are occupied by nesting willow 

flycatchers, capability of the meadow to maintain surface water throughout the breeding season, adequate 

willow cover, etc. Therefore, although motorized routes may adversely affect meadow vegetation and 

hydrology, stabilized routes may not necessarily cause meadow degradation at these emphasis meadows.

Following Alternative 6, Alternatives 2, 5, and 7 similarly affect willow flycatcher Emphasis meadow 

habitat, where 2 meadows (Castle Valley and Loney Meadow) are intersected by about 0.1 mile of 

proposed route additions (TKN-J5 and D-18-19_b). Alternative 4 only proposes to add route D-18-19_b 

that accesses a dispersed site route which intersects Loney Meadow. 

Table 3.03-103. Number of willow flycatcher meadow sites intersected by motorized route additions 

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Willow Flycatcher meadow sites intersected by motorized route additions

Occupied Meadows Intersected by Route Additions (13) 4 0 0 0 0 0 0

Occupied Meadow Miles 1.16 0 0 0 0 0 0

Emphasis Meadows Intersected by Route Additions (30) 18 2 0 1 2 5 1

Emphasis Meadows Miles 2.84 0.13 0 0.02 0.13 0.17 0.12

Total Number Meadows with Route Additions 22 2 0 1 2 5 1

Total Miles of Route Additions in Meadows 4.0 0.13 0 0.02 0.13 0.17 0.12

*Alternative 1 includes existing unauthorized routes with continued cross country travel.

Table 3.03-104. Miles of Motorized Route Additions with willow flycatcher Emphasis Meadows by Route ID 

Meadow Name Route ID Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Unauthorized routes N/A 2.84 N/A N/A N/A N/A N/A N/A

Castle Valley TKN-J5 0 0.11 0 0 0.11 0.12 0.12

Castle Valley D_TKN-J5_b 0 0 0 0 0 0.01 0

Castle Valley D_TKN-J5_c 0 0 0 0 0.01 0

Loney Meadow D-18-19_b 0 0.02 0 0.02 0.02 0.02 0

Meathouse Meadow D-350-10 0 0 0 0 0 0.01 0

Nichols Mill D_15-20 0 0 0 0 0 0.001 0

Sagehen D_N886-18c 0 0 0 0 0 0.002 0

Total Miles 2.84 0.13 0 0.02 0.13 0.17 0.12

*Alternative 1 includes existing unauthorized routes with continued cross country travel.

Changes to the NFTS

Change in Class of Vehicles: The change in class of vehicle proposed under Alternatives 2, 4, 5, 6, and 

7, on some existing NFTS motorized roads may result in some smoothed surfaced roads becoming rough 

surfaced roads through changed road maintenance. In addition, some existing motorized NFTS roads may 

receive different maintenance resulting in increased vegetation density at the road margins which would 

provide additional cover and/or foraging habitat. The resulting roadway condition would depend upon the 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 377

amount and type of vegetation present and the type of maintenance any given road receives. For the 

willow flycatcher existing habitat conditions will dictate whether or not the change in class of vehicle will 

result in reduced habitat quality. In general, it is not expected that the change in class of vehicle would 

result in a significant change to willow flycatcher habitat conditions, unless different road maintenance 

results in increased meadow habitat degradation. No changes in class of vehicle are proposed under 

Alternatives 1 and 3, which means that some system routes would remain under their current maintenance 

management strategy. However, in some cases some existing system roads have already become rough 

surfaced due to changes in maintenance.

Wet Weather Seasonal Restrictions: Alternatives 4, 5, and 6 would impose wet weather seasonal 

restrictions on all native surfaced roads and motorized trails where willow flycatcher occupied and 

emphasis meadows would be benefited through the reduction of erosion and sedimentation that might

otherwise occur during the wet season. Alternative 1, with the greatest miles of motorized routes that 

intersect the most number of willow flycatcher meadows, which would continue to be impacted by 

motorized use during the wet weather season, where habitat degradation within willow flycatcher 

meadows could occur. Roads have often been cited as being the source of resource damage and habitat 

degradation to meadows including those potentially used by willow flycatchers.

Reopened ML 1 Roads: Only Alternative 5 proposes to reopen ML 1 roads. Alternative 5 proposes 

to reopen 0.12 miles of ML 1 road (H823-1-1) affecting one willow flycatcher emphasis meadow site at 

Howard Creek. Alternative 5 does not propose to reopen any ML 1 roads that would affect any willow 

flycatcher occupied sites, and therefore would not affect any known willow flycatcher nesting sites.

Under Alternative 5, reopening ML1 road within one emphasis meadow site at Howard Meadow could 

adversely affect the meadow vegetation and hydrology that may prevent the reestablishment of willow 

flycatchers.

Amendments to Forest Plan

The alternatives would not result in affecting willow flycatcher habitat from Amendments to the Forest 

Plan, since willow flycatcher habitat does not occur in areas where the season of motorized use in deer 

winter areas would be altered within the Humbug-Sailor Management Area.

Summary of Direct and Indirect Effects

Table 3.03-105 summarizes the overall net direct and indirect effect of the alternatives from cross country 

travel, establishment of “Open Areas,” motorized route additions to the NFTS, changes to the NFTS, and 

amendments to the Forest Plan.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

378 – Tahoe National Forest

Table 3.03-105. Willow Flycatcher - Summary of Overall Net Direct and Indirect Effects

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Occupied 

Meadows

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres Cross Country Travel 

Prohibited

0 1,747 1,747 1,747 1,747 1,747 1,747

Emphasis 

Meadows

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres Cross Country Travel 

Prohibited

0 1,328 1,328 1,328 1,328 1,328 1,328

Total acres benefited 0 3,075 3,075 3,075 3,075 3,075 3,075

Total Occupied and Emphasis Meadows 

Prohibited to Cross Country Travel

0 20 21 19 19 18 20

Total Miles in Occupied and Emphasis 

Meadows Prohibited to Cross Country 

Travel

0 3.87 4.01 3.86 3.74 3.84 3.89

Establishment of “Open Areas” No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Motorized Route Additions

Occupied 

Meadows

Trend of Effect Negative No Effect No Effect No Effect No Effect No Effect No Effect

# Meadows Intersected 4 0 0 0 0 0 0

Miles 1.16 0 0 0 0 0 0

Emphasis 

Meadows

Trend of Effect Negative Negative No Effect Negative Negative Negative Negative

# Meadows Intersected 18 2 0 1 2 5 1

Miles 2.84 Miles 0.13 Miles 0 Miles 0.02 Miles 0.13 Miles 0.17 Miles 0.12 Miles
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Tahoe National Forest – 379

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Changes to the NFTS

Wet Weather Restrictions No Effect No Effect No Effect Beneficial Beneficial Beneficial No Effect

Change in Class of Vehicles No Effect Localized 

negative 

effects.

No Effect Minor negative 

effect. 

Localized 

negative effects.

Localized 

negative 

effects.

Minor negative 

effect.

Reopened 

ML 1 

Roads

Occupied 

Meadows

Trend of Effect No Effect No Effect No Effect No Effect No Effect No Effect No Effect

# Meadows 

Intersected

0 0 0 0 0 0 0

Miles 0 0 0 0 0 0 0

Emphasis 

Meadows

Trend of Effect No Effect No Effect No Effect Negative Negative No Effect No Effect

# Meadows 

Intersected

0 0 0 0 2 0 0

Miles 0 0 0 0 0.14 0 0

Amendments to Forest Plan No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Overall Net Effect of Proposed Actions Negative effects 

from continued 

cross country 

travel on 22

occupied and 

emphasis 

meadows on 4

miles of existing 

unauthorized

routes.

Benefits within 

20 occupied 

and emphasis 

meadows on 

3.86 miles of 

existing 

unauthorized 

routes where 

cross country 

travel is 

prohibited; 

although 

minor 

negative 

impacts from 

route 

additions; 

overall 

reduces 

disturbance 

and habitat 

fragmentation.

Benefits within 22

meadows on 4.0 

miles of existing 

unauthorized routes 

where cross country 

travel is prohibited; 

overall reduces 

disturbance and 

habitat 

fragmentation.

Benefits within 21

meadows on 

approx. 3.85 miles 

of existing 

unauthorized 

routes where cross 

country travel is 

prohibited;although 

minor negative 

impacts from route 

additions; overall 

reduces 

disturbance and 

habitat 

fragmentation.

Benefits within 18

meadows on 3.7 

miles of existing 

unauthorized 

routes where 

cross country 

travel is 

prohibited;

although minor 

negative impacts 

from route 

additions and 

reopened ML 1 

roads; overall 

reduces 

disturbance and 

habitat 

fragmentatio.

Benefits within 

17 meadows 

on 3.8 miles of 

existing 

unauthorized

routes where 

cross country 

travel is 

prohibited

although minor 

negative 

impacts from 

route 

additions; 

overall 

reduces 

disturbance 

and habitat 

fragmentation.

Benefits within 

21 meadows 

on 3.9 miles of 

existing 

unauthorized

routes where 

cross country 

travel is 

prohibited

although minor 

negative 

impacts from 

route 

additions; 

overall

reduces 

disturbance 

and habitat 

fragmentation..

*Alternative 1 includes existing unauthorized routes that would continue with cross country travel, while all the action alternatives include proposed route additions.
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380 – Tahoe National Forest

Cumulative Effects

Cumulative Effects Boundary

The cumulative effects analysis geographic boundary for the willow flycatcher includes all willow 

flycatcher sites occurring within the Tahoe NF boundary, both within NFS lands and non-NFS lands. See 

Terrestrial and Aquatic Species Introduction Section for the rationale. The temporal scale for analyzing 

cumulative effects to willow flycatcher is approximately 20 years into the past and 20 years out into the 

future.

Overall Cumulative Effects to Willow Flycatcher Meadows

Cumulative impacts to the willow flycatcher include past, present, and future impacts from livestock 

grazing, roads, and recreational activities. The Forest Service has completed a Conservation Assessment 

of the Willow Flycatcher in the Sierra Nevada (Green et al. 2003), which identified meadow drying, loss 

of nesting and foraging substrates (riparian shrubs), increased predator access to meadow interiors, and 

potential cowbird parasitism as among the key factors likely responsible for the decline of the willow 

flycatcher. Livestock management, recreation, water developments, and roads are described as causative 

factors.

Historic livestock grazing has impacted montane meadows and is considered to be a primary factor 

that has influenced the suitability of willow flycatcher habitat and meadow habitat for birds in the Sierra 

Nevada (Graber 1996, Green et al. 2003, Menke et al. 1996). Many of the landbird species utilizing these 

meadows feed upon insects that decline in response to removal of this herbaceous growth (Graber 1996). 

Poorly managed grazing in riparian areas can impact nesting densities of many bird species, and 

particularly of habitat specialists such as the willow flycatcher, Lincoln’s sparrow, and white-crowned 

sparrow (RHJV 2004). 

Livestock grazing on active allotments currently affects willow flycatcher meadow habitat on the 

Forest. Trend data from Regional range meadow monitoring was available for 15 willow flycatcher 

meadow sites on the Tahoe NF. Of the 15 Occupied and Emphasis sites monitored, habitat trend is either 

up or stable on 73% of sites and trend was down on 27% of the sites.

Non-motorized trails allow for backcountry hiking and camping, which may occur in meadows not 

accessed by motorized routes, and can adversely affect additional meadow habitat or disturb species. 

These activities are generally dispersed and of low impact to habitat, particularly in sites most suitable for 

willow flycatcher, which are typically very wet. Foreseeable future projects listed in the Tahoe Schedule 

of Proposed Actions do not indicate additional cumulative effects would occur.

Watershed restoration work continues to be a priority on the Tahoe NF. During 2009, watershed 

restoration at Perazzo Meadows is currently underway, with the intent to increase water storage 

capabilities and improve vegetation conditions. Perazzo Meadows is an important willow flycatcher 

breeding site in the Sierra Nevada. Maintaining and improving habitat conditions for the willow 

flycatcher at Perazzo Meadows and the Little Truckee River meadow system is integral to the long-term 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 381

sustainability and viability for this species in the Sierra Nevada. Long-term benefits to the willow 

flycatcher and its habitat are expected to occur from this watershed restoration effort.

Cumulative Effects from Motorized Routes to Willow Flycatcher Meadows

Factors responsible for the decline of willow flycatcher populations in the Sierra Nevada are primarily 

thought to be the result of habitat change, particularly the alteration of meadow hydrology, specifically 

caused by roads (Green et al. 2003).

Table 3.03-106 displays the cumulative impacts of motorized and non-motorized routes within 

meadows that are designated as either willow flycatcher Occupied or Emphasis habitat. Occupied habitat 

are sites where willow flycatcher breeding is either known or suspected. Routes intersecting Occupied 

habitat have the highest potential to impact breeding willow flycatchers. Emphasis habitat are meadows 

that are currently not occupied by breeding willow flycatcher, but are considered to be suitable willow 

flycatcher nesting habitat that are within 5 miles of Occupied Sites where dispersing willow flycatchers 

may nest in the near future. Emphasis habitats are particularly important so that willow flycatchers may 

have future refugia where their population can be distributed and expand in the future.

Occupied Habitat

Alternatives 1 would contribute to existing cumulative impacts to Occupied willow flycatcher sites. 

Alternative 1 cumulatively adds, approximately 1.2 miles of existing unauthorized routes, affecting 4 

Occupied meadow sites (31% of meadows identified as Occupied) where direct and indirect impacts to 

meadow vegetation and hydrology could occur. Hydrologic condition is an important habitat component

to consider for successful willow flycatcher breeding. Given the uncertainty of future route proliferation 

under Alternative 1, the future habitat alteration within Occupied meadow sites is potentially at risk, and 

may ultimately affect willow flycatcher breeding success within Occupied habitats. 

The action alternatives (Alternatives 2, 3, 4, 5, 6, and 7) do not add to existing cumulative impacts 

within occupied willow flycatcher sites, and therefore would not impact breeding willow flycatchers. In 

addition, all the action alternatives would prohibit the proliferation of new motorized routes through cross 

country motorized travel that would adversely alter habitat within Occupied sites. Finally, all the action 

alternatives would benefit willow flycatcher breeding habitat by prohibiting cross country travel, 

including use on unauthorized routes on approximately 1.2 miles within 3 Occupied meadow sites.

Emphasis Habitat 

Emphasis habitats are meadow sites within 5 miles of known breeding sites (Occupied habitat) that are 

considered to provide suitable nesting habitat for willow flycatcher. Alternative 1 poses the greatest risk to 

the future colonization by willow flycatcher within Emphasis habitats, since cross country travel would 

not be prohibited, including use on unauthorized routes that intersect 18 Emphasis sites (60% of all 

Emphasis sites) for a total of about 2.8 miles.

All the action alternatives would benefit willow flycatcher emphasis habitats by prohibiting cross 

country travel on existing unauthorized routes. Of the action alternatives, Alternative 5 would benefit 
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382 – Tahoe National Forest

willow flycatcher emphasis sites the least where cross country travel would be prohibited within 17 

meadows on 3.7 miles of unauthorized routes. Alternative 5 would add to cumulative impacts within 4 

Emphasis sites (13% of all Emphasis sites) from proposed motorized route additions to the NFTS and 

reopened ML 1 roads, totaling approximately 0.28 miles. Alternatives 6, 4, 2, 7, and 3 benefit willow 

flycatcher emphasis sites in descending order, ranging from 18-21 meadows where cross country travel 

would be prohibited on between 3.8 to 4 miles on existing unauthorized routes.

Alternatives 2, 4, 6, and 7 would result in affecting between 1 to 5 Emphasis sites (Alt 7 – the least, 

Alt 6 – the most) intersected by motorized route additions and/or reopened ML 1 roads, for less than 0.2

mile total for each alternative. Alternative 3 does not add to existing cumulative impacts to Emphasis 

habitats, since no motorized route additions or reopened ML 1 roads would result in the intersection of

any willow flycatcher Emphasis sites.

Summary of Cumulative Effects to Willow Flycatcher Habitat:

Occupied and Emphasis Meadows

Alternative 1 poses the greatest overall risk to known nesting sites and potentially suitable nesting sites 

from all routes including use on existing unauthorized routes associated with cross country travel, existing 

motorized routes (both NFS and non-NFS), and non-motorized routes. Alternative 1 results in willow 

flycatcher meadows being intersected 55 times for a total of about 12 miles by routes of any category. 

Over 30% of meadows identified as Occupied are impacted by existing unauthorized routes, which could 

substantially alter the meadow vegetation and hydrology and reduce breeding success at known nesting 

sites of a species that is at risk of extirpation. Therefore, Alternative 1 could contribute to the downward 

trend of willow flycatcher populations on the Tahoe NF.

Alternative 5 results in the next highest overall cumulative impact where Occupied and Emphasis 

meadows combined are intersected by a motorized or non-motorized route 39 times totaling about 8.4

miles. The remaining action alternatives do not add to existing cumulative impacts to Occupied habitat, 

however Alternatives 2, 4, 5, 6, and 7 do contribute to cumulative impacts to 1 to 5 Emphasis meadow 

sites depending on the alternative where relatively short route segments would intersect a meadow (0.1 to 

0.3 mile).

The action alternatives all prohibit cross country travel, including motorized use on between 3.7 miles 

to 4.0 miles of unauthorized routes (Alt. 5 prohibits the least, Alt. 3 prohibits the most) within suitable 

willow flycatcher habitats (Occupied and Emphasis meadows). It is expected that non-motorized use 

(hiking, mountain bicycling, equestrian, etc.) may occur on these routes in the future. In general, benefits 

to willow flycatcher habitat would be realized as vegetation and soil impacts from non-motorized use 

recover over time through active and passive restoration efforts. Under Alternative 1, these benefits would 

not be realized since cross country travel would not be prohibited and use on existing unauthorized routes

would continue and likely proliferate. 

Foreseeable future projects on the Tahoe NF include undertaking a variety of meadow restoration 

projects that would result in benefits to willow flycatcher (i.e. Perazzo Meadows) and its habitat.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 383

Table 3.03-106. Cumulative Effects to Willow Flycatcher Meadows - Occupied and Emphasis Meadows 

Intersected by Routes

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Total Number of Willow Flycatcher Sites Intersected by 

motorized route additions to the NFTS (negative impact)1 22 2 0 1 4 5 1

Total Miles 4.0 0.13 0 0.02 0.13 0.17 0.12

Number of Occupied Sites 4 0 0 0 0 0 0

Miles within Occupied Sites 1.16 0 0 0 0 0 0

Number of Emphasis Sites 18 2 0 1 2 5 1

Miles within Emphasis 2.68 0.13 0 0.02 0.13 0.13 0.12

Total Number Meadows with Reopened ML 1 Roads

(negative impact)

0 0 0 0 2 0 0

Total Miles of Reopened ML 1 Roads in Meadows

(negative impact)

0 0 0 0 0.14 0 0

Number of Occupied Sites 0 0 0 0 0 0 0

Miles within Occupied Sites 0 0 0 0 0 0 0

Number of Emphasis Sites 0 0 0 0 2 0 0

Miles within Emphasis 0 0 0 0 0.14 0 0

Total Number of Willow Flycatcher Sites Intersected by 

Unauthorized Routes prohibited to cross country travel 

(positive impact)

0 20 22 21 18 17 21

Total Miles 0 3.9 4.0 3.9 3.7 3.8 3.9

Number Occupied Sites 0 3 3 3 3 3 3

Miles within Occupied 0 1.17 1.17 1.17 1.17 1.17 1.17

Number Emphasis Sites 0 17 18 16 16 15 18

Miles within Emphasis 0 2.70 2.84 2.69 2.57 2.67 2.72

Cumulative effects

Total Number of Willow Flycatcher Sites Intersected by 

Existing NFTS motorized routes - NFS lands

(negative impact)

20 20 20 20 20 20 20

Total Miles 2.74 2.74 2.74 2.74 2.74 2.74 2.74

Number Occupied Sites 7 7 7 7 7 7 7

Miles within Occupied 1.05 1.05 1.05 1.05 1.05 1.05 1.05

Number Emphasis Sites 13 13 13 13 13 13 13

Miles within Emphasis 1.69 1.69 1.69 1.69 1.69 1.69 1.69

Total Number of Willow Flycatcher Sites Intersected by 

Existing motorized routes on - non-NFS lands (private) 

(negative impact)

8 8 8 8 8 8 8

Total Miles 4.26 4.26 4.26 4.26 4.26 4.26 4.26

Number Occupied Sites 2 2 2 2 2 2 2

Miles within Occupied 3.83 3.83 3.83 3.83 3.83 3.83 3.83

Number Emphasis Sites 6 6 6 6 6 6 6

Miles within Emphasis 0.43 0.43 0.43 0.43 0.43 0.43 0.43
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384 – Tahoe National Forest

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Total Number of Willow Flycatcher Sites Intersected by 

Existing non-motorized routes (negative impact)

5 5 5 5 5 5 5

Total Miles 1.03 1.03 1.03 1.03 1.03 1.03 1.03

Number Occupied Sites 1 1 1 1 1 1 1

Miles within Occupied 0.14 0.14 0.14 0.14 0.14 0.14 0.14

Number Emphasis Sites 4 4 4 4 4 4 4

Miles within Emphasis 0.89 0.89 0.89 0.89 0.89 0.89 0.89

Total Number of Willow Flycatcher Sites Intersected by 

Decommissioned routes (positive impact)

3 3 3 3 3 3 3

Total Miles 0.49 0.49 0.49 0.49 0.49 0.49 0.49

Number Occupied Sites 1 1 1 1 1 1 1

Miles within Occupied 0.29 0.29 0.29 0.29 0.29 0.29 0.29

Number Emphasis Sites 2 2 2 2 2 2 2

Miles within Emphasis 0.20 0.20 0.20 0.20 0.20 0.20 0.20

Total Number of NFTS Roads Closed by Previous NEPA 

decisions, pending implementation (positive impact)

3 3 3 3 3 3 3

Total Miles 0.10 0.10 0.10 0.10 0.10 0.10 0.10

Number Occupied Sites 3 3 3 3 3 3 3

Miles within Occupied 0.10 0.10 0.10 0.10 0.10 0.10 0.10

Number Emphasis Sites 0 0 0 0 0 0 0

Miles within Emphasis 0 0 0 0 0 0 0

Total Cumulative Effects

Number of Times a Meadow is Intersected by

Motorized Routes 

55 35 33 34 39 38 34

Net Cumulative Impacts = Sum Total Miles of All Routes 

both positive and negative that Intersect Willow 

Flycatcher Sites

11.87 8.16 8.03 8.05 8.44 8.20 8.15

*Alternative 1 includes the existing unauthorized routes associated with continued with cross country travel, while all action 

alternatives include motorized route additions.

Sensitive Species Determination

The Biological Evaluation for the Tahoe NF Motorized Travel Management Project (incorporated by 

reference) made a determination that the proposed action may affect willow flycatchers, but is not likely 

to lead to a trend toward federally listing or a downward trend in population viability. The action 

alternatives all prohibit motorized cross country travel, including use of existing unauthorized routes. 

Furthermore, wet weather seasonal restrictions reduce the likelihood of sedimentation and erosion that 

may occur from wet weather motorized use for Alternatives 4, 5, and 6.

Compliance with Forest Plan and Other Direction

The Tahoe NF LRMP, as amended by the SNFPA ROD (2004), provides management direction for 

managing willow flycatcher habitat, including direction for managing meadows, wetlands, and Riparian 

Conservation Areas that are applicable to willow flycatcher habitat as follows:
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 385

• Locate roads away from meadow edges where alternative routes are available (Tahoe LRMP)

(Management Standard & Guideline): 

• Avoid wetlands or minimize effects to natural flow patterns in wetlands and avoid road 

construction in meadows.

• Evaluate new proposed management activities within CARs and RCAs during environmental 

analysis to determine consistency with the riparian conservation objectives (RCOs) at the project 

level and the AMS goals for the landscape. Ensure that appropriate mitigation measures are 

enacted to (1) minimize the risk of activity-related sediment entering aquatic systems and (2) 

minimize impacts to habitat for aquatic- or riparian-dependent plant and animal species 

(Management Standard & Guideline 92).

• Maintain and restore the hydrologic connectivity of streams, meadows, wetlands, and other special 

aquatic features by identifying roads and trails that intercept, divert, or disrupt natural surface 

and subsurface water flow paths. Implement corrective actions where necessary to restore 

connectivity (RCO#2, Management Standard & Guideline 100).

In the above sections, the Proposed Action and alternatives for the Tahoe NF Motorized Travel 

Management Project were analyzed for their potential effects to willow flycatcher meadow and riparian 

habitats which addresses the above management standard and guidelines as they apply to willow 

flycatcher habitats. Mitigation measures for the action alternatives to minimize the risk of sediment and 

streambank alteration from proposed motorized route additions to the NFTS and existing unauthorized 

routes are addressed in the Riparian Conservation Objective (RCO) analysis and Appendix A (Site 

Specific Road, Trail and Open Area Information).

Alternative 1 is least consistent with the above standards and guidelines for managing meadows in 

terms of maintenance and hydrologic connectivity of meadows, avoidance of roads near and within 

meadows, and minimizing effects to meadow condition and function. Alternative 1 continues cross 

country travel, including within 22 willow flycatcher meadows on approximately 4 miles of existing 

unauthorized routes.

All of the action alternatives meet these standards and guidelines by improving willow flycatcher 

habitat conditions. The action alternatives all prohibit cross country travel on 3,075 willow flycatcher 

meadow acres, and reduces the impacts of 18 to 21 willow flycatcher meadows where there would be 

approximately 3.7 miles to 4.0 miles. All the action alternatives considerably improve meadow function 

and connectivity for the willow flycatcher, since the project design standards were developed to minimize 

impacts to willow flycatcher meadows and riparian habitat through the implementation of wet weather 

seasonal restrictions, does not propose motorized route additions within any Occupied willow flycatcher 

meadow, and bans cross country motorized travel. 

Great Gray Owl: Affected Environment

The great gray owl is listed as Sensitive on the Region 5 Forester’s Sensitive Species List (USDA Forest 

Service 1998). In the Sierra Nevada, great gray owls are found in mixed coniferous forest from 2,400 to 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

386 – Tahoe National Forest

9,000 feet elevation where such forests occur in combination with meadows or other vegetated openings. 

Nesting usually occurs within 600 feet of the forest edge and adjacent open foraging habitat. Most nests 

are made in broken top snags (generally firs), but platforms such as old hawk nests, mistletoe infected 

limbs, etc. are also used. Nest trees or snags are generally greater than 21 inches dbh and 20 feet tall.

In the Sierra Nevada, pocket gophers and voles appear to be important prey species (Winter 1982, 

Reid 1989). Meadows appear to be the most important hunting habitat for great gray owls, where 

approximately 93% of their prey is taken (Winter 1981).

Recent great gray owl sightings in our area include an adult located three miles north of Nevada City 

(1/96), an adult on private land near the town of Alleghany (5/2006, 4/2007), a vocalization of an adult 

detected by CDFG and Sierra Pacific industries on the Sierraville RD in 2005 and 2008), and two adults 

found in the Feather River Ranger District of the Plumas NF (8/97). In recent years, numerous surveys for 

great gray owl have been conducted on the Tahoe NF, and have only resulted in a handful of single great 

gray owl detections, with no confirmation of nesting.

Roads and motorized trails can potentially affect great gray owl habitat by affecting the condition of 

suitable great gray owl habitat in similar ways that affects willow flycatcher habitat, primarily through 

changes in meadow hydrology or when damage to meadow vegetation occurs. Compaction and meadow 

drying can cause changes in vegetation composition which can lead to changes in prey species abundance 

and distribution. Changes in prey availability and abundance can affect reproduction success of great gray 

owls.

Great Gray Owl: Environmental Consequences

The Tahoe NF LRMP as amended by the SNFPA ROD (2004) provides management direction to establish 

and maintain Protected Activity Centers (PACs) to include the forested area and adjacent meadow around 

all known great gray owl nest stands. The desired condition for meadow vegetation in great gray owl 

PACs supports a sufficiently large meadow vole population to provide a food source for great gray owls 

through the reproductive period. Although the Tahoe NF does not currently support known great gray owl 

nesting pairs, potentially suitable great gray owl meadows were analyzed to determine potential impacts 

from the Tahoe NF Travel Management Project.

Indicators used to Measure Effects

Cross Country Travel: The prohibition of cross country travel is analyzed for their effects to potential 

great gray owl breeding habitat.

Additions to the NFTS (Number of Great Gray Owl Meadows Intersected): meadows identified 

as suitable for great gray owl foraging that are adjacent to suitable breeding habitat were assessed to 

determine the potential impact from proposed motorized route additions. The number of great gray owl 

meadows that are intersected by motorized route additions to the NFTS are assessed for the alternatives.

Establishment of “Open Areas”: The establishment of “Open Areas” at Greenhorn Creek and 

Reservoir areas (Prosser, Stampeded and Boca) is evaluated for their potential to affect potential great 

gray owl habitat.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 387

Changes to the NFTS

Change in Class of Vehicles: The changes in class of vehicle was analyzed for their potential to affect 

potential great gray owl meadow habitat (no known breeding sites, but potentially suitable breeding 

habitat exists), since this action potentially changes the condition of the existing road surface from 

smoothed surfaced to rough surfaced; which could potentially alter meadow condition where routes 

intersect or are within close proximity to motorized routes.

Wet Weather Seasonal Restrictions: In addition to existing deer seasonal restrictions specified in 

the Tahoe Forest Plan, wet weather seasonal restrictions would apply to specific alternatives. The benefits 

to great gray owl with these additional wet weather closures are analyzed for the alternatives.

Reopened ML 1 Roads: Meadows identified as suitable for great gray owl foraging that are adjacent 

to suitable breeding habitat were assessed to determine the potential impact from proposed reopening of 

ML 1 Roads. The number of great gray owl meadows that are intersected by reopened ML 1 roads are 

assessed for the alternatives.

Amendments to the Forest Plan: the proposal to remove deer winter range seasonal closures in the 

Humbug-Sailor area is evaluated to assess potential effects to suitable great gray owl habitat.

Direct and Indirect Effects

Cross Country Travel: Under Alternative 1, cross country travel would not be prohibited on 3,165 acres 

of potential great gray owl meadow habitat across the Tahoe NF. All the action alternatives prohibits cross 

country travel on 3,165 acres of potential great gray owl meadow habitat, including on 5-6 miles of 

unauthorized routes. Therefore, benefits to great gray owl habitat would occur under all the action 

alternatives, whereas Alternative 1 would potentially result in habitat degradation of suitable great gray 

owl habitat on the Tahoe NF, including within 21 suitable great gray owl meadows, on nearly 6 miles of 

unauthorized routes.

Additions to the NFTS: Potential great gray owl habitat has been identified on the Tahoe NF. A total 

of 41 meadow sites on the Forest are considered suitable foraging habitat areas for the great gray owl. 

These potential foraging sites were evaluated to determine the potential indirect effects to meadow 

vegetation and hydrology which may affect the suitability of potential great gray owl nesting/foraging 

habitat. Alternative 1 poses the greatest risk to potential great gray owl meadows where 21 meadows 

(51%) are intersected by existing unauthorized motorized routes, where motorized use could continue 

associated with cross country travel, totaling approximately 6 miles (Table 3.03-107). This amount of 

motorized routes could alter meadow vegetation and hydrology that would indirectly affect great gray owl 

breeding habitat where great gray owls forage and where the future to occupy these areas may be limited. 

Alternatives 5 and 6, each would result in intersecting 5 (12%) great gray owl meadow sites, where the 

future establishment of great gray owls could be affected. However, Alternative 5 would affect nearly 

three times the amount of meadow compared to Alternative 6 (0.3 mile vs. 0.1 mile), which would 

potentially reduce habitat quality in great gray owl meadows from motorized route additions. The 

remaining action alternatives either do not impact potential great gray owl meadows (Alternative 3), or 

minimally impacts great gray owl meadows where less than 0.1 miles of meadows would be affected.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

388 – Tahoe National Forest

Table 3.03-107. Number of Great Gray Owl Meadows Intersected by Motorized Route Additions

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Number of Meadows with Intersections 21 3 0 1 5 5 2

Miles 5.93 0.05 0 0.02 0.27 0.09 0.04

* Alternative 1 includes the existing unauthorized routes associated with cross country travel, while all action alternatives include 

motorized route additions to the NFTS.

Changes to the NFTS

Change in Class of Vehicles. The change in class of vehicle proposed under Alternatives 2, 4, 5, 6, and 7, 

on some existing NFTS motorized routes may result in some smoothed surfaced roads becoming rough 

surfaced roads through reduced road maintenance. In addition, some existing motorized NFTS roads may 

receive different maintenance resulting in increased vegetation density at the road margins which would 

provide additional cover and/or foraging habitat. The resulting roadway condition would depend upon the 

amount and type of vegetation present and the amount of maintenance any given road receives. For the 

great gray owl, existing habitat conditions will dictate whether or not the change in class of vehicle will 

result in reduced habitat quality. In general, it is not expected that the change in class of vehicle would 

result in a significant change to great gray owl habitat conditions, unless different road maintenance 

results in increased meadow habitat degradation. No changes in class of vehicle are proposed under 

Alternatives 1 and 3, which means that some system routes would remain under their current maintenance 

management strategy. However, in some cases some existing system roads have already become rough 

surfaced due to different of maintenance.

Wet weather seasonal restrictions. Alternatives 4, 5, and 6 would impose wet weather seasonal 

restrictions on all native surfaced roads and motorized trails. Since no suitable great gray owl meadow 

habitat would be affected by Alternative 3 wet weather seasonal restrictions would not affect great gray 

owl habitat. Under Alternatives 5 and 6, great gray owl meadows that are intersected by native, surfaced 

motorized routes would be benefited through the reduction of erosion and sedimentation that could occur 

during the wet season. Alternative 1 with the greatest miles intersecting the most number of great gray 

owl meadows, would continue to be impacted by motorized use during the wet weather season, where 

habitat degradation within these meadows could occur.

Reopened ML 1 Roads: Only Alternative 5 proposes to reopen any ML 1 roads within suitable great 

gray owl meadows (Table 3.03-108). Alternative 5 potentially affects two suitable great gray owl 

meadows totaling 0.21 miles, which may potentially adversely affect meadow vegetation and hydrologic 

condition within Howard Creek Meadow (Road ID - H823-1-1) and Russel Valley/Dry Creek (Road ID -

H889-3-18-5.

Table 3.03-108. Number of Great Gray Owl Meadows Intersected by Reopened ML 1 Roads

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Number of Meadows with Intersections 0 0 0 0 2 0 0

Miles 0 0 0 0 0.21 0 0
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 389

Summary of Direct and Indirect Effects

Table 3.03-109 summarizes the overall net direct and indirect effect of the alternatives from cross country 

travel, motorized route additions to the NFTS, establishment of “Open Areas,” changes to the NFTS (wet 

weather restrictions, changes in class of vehicles, and reopened ML 1 roads), and amendment to the 

Forest Plan.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

390 – Tahoe National Forest

Table 3.03-109. Great Gray Owl - Summary of Overall Net Direct and Indirect Effects of the Alternatives

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres Cross Country Travel 

Prohibited

0 3,165 3,165 3,165 3,165 3,165 3,165

Motorized Route Additions to the NFTS

Trend of Effect Negative, most 

impactive 

alternative

Negative, 4th

most impactive 

alternative

No Effect Negative, 6th

most impactive 

alternative

Negative, 2nd

most impactive 

alternative 

following Alt 1

Negative, 3rd

most impactive 

alternative

Negative, 5th

most impactive 

alternative

Number Meadows Intersected 21 3 0 1 5 5 2

Miles 5.9 0.05 0 0.02 0.27 0.09 0.04

Establishment of “Open Areas” No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Changes 

to the 

NFTS

Wet Weather Restrictions No Effect No Effect No Effect Beneficial Beneficial Beneficial No Effect

Change in Class of 

Vehicles

No Effect Localized 

Negative 

Effects

No Effect No Effect Localized 

Negative 

Effects

No Effect Localized 

Negative 

Effects

Reopened 

ML 1 

Roads

Trend of 

Effect

No Effect No Effect No Effect No Effect Negative No Effect No Effect

Number

Meadows 

Intersected

0 0 0 0 2 0 0

Miles 0 0 0 0 0.21 0 0

Amendments to the Forest Plan No Effect No Effect No Effect No Effect No Effect No Effect No Effect
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 391

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Overall Net Effect of Proposed 

Actions

Negative effect 

due to 

continued cross 

country travel 

on 3,165 habitat 

acres within 21 

meadows on

5.9 miles of 

unauthorized 

routes.

Beneficial –

Cross country 

travel prohibited 

on 3,165 habitat 

acres, including 

within 17

meadow on 5.8

miles of

unauthorized 

routes; although 

minor negative 

impacts from 

route additions; 

overall reduces 

disturbance and 

habitat 

fragmentation.

Beneficial –

Cross country 

travel.prohibited 

on 3,165 habitat 

acres, including 

within 20

meadows on 

5.9 miles of 

unauthorized 

routes of 

unauthorized 

routes; overall 

reduces 

disturbance and 

habitat 

fragmentation.

Beneficial –

Cross country 

travel.prohibited 

on 3,165 habitat 

acres, including 

within 18

meadows on 

5.4 miles of 

unauthorized 

routes; although 

minor negative 

impacts from 

route additions; 

overall reduces 

disturbance and 

habitat 

fragmentation..

Beneficial –

Cross country 

travel.prohibited 

on 3,165 habitat 

acres, including 

within 16

meadows on 5.3 

miles of 

unauthorized 

routes; although 

minor negative 

impacts from 

route additions 

and reopened ML 

1 roads; overall 

reduces 

disturbance and 

habitat 

fragmentation.

Beneficial –

Cross country 

travel.prohibited 

on 3,165 habitat 

acres, including 

within 16

meadows on 5.7 

miles of 

unauthorized 

routes; although 

minor negative 

impacts from 

route additions; 

overall reduces 

disturbance and 

habitat 

fragmentation.

Beneficial –

Cross country 

travel.prohibited 

on 3,165 habitat 

acres, including 

within 19 

meadows on 5.9

miles of 

unauthorized 

routes; although 

minor negative 

impacts from 

route additions; 

overall reduces 

disturbance and 

habitat 

fragmentation.

*Alternative 1 includes existing unauthorized routes that would continue with cross country travel, while all the action alternatives include proposed route additions.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

392 – Tahoe National Forest

Cumulative Effects

The geographic boundary for analyzing cumulative effects to great gray owls includes 41 suitable great 

gray owl meadow habitat sites within the boundary of the Tahoe NF. These meadows fall within a broad 

geographic distributional range from eastside to westside of the Sierra crest, and they occur within a 

diversity of vegetation types. The adjacent forest types surrounding these great gray owl meadow areas 

include eastside pine, eastside mixed conifer, true fir types, and, westside mixed conifer forests.

The action alternatives are analyzed for cumulative effects of motorized and non-motorized routes to 

suitable great gray owl habitat that may affect the ability for great gray owls to occupy these sites. 

Cumulative effects include routes that are on both public and private lands. Decommissioned routes are 

considered positive cumulative effects. 

Alternative 1 poses the greatest cumulative risk to suitable great gray owl habitat where suitable great 

gray owl meadows are intersected by a motorized or non-motorized route on both NFS and non-NFS 

lands 53 times for a total of 14 miles (Table 3.03-110). Currently 21 great gray owl meadows are affected 

by approximately 6 miles of existing unauthorized routes. The uncertainty of future motorized route 

proliferation could alter meadow vegetation and hydrology that would impact habitat conditions for great 

gray owl prey species in the long term. It is expected that OHV use would continue and increase, 

therefore Alternative 1 could adversely affect the potential for great gray owls to occupy these sites in the 

near and distant future. In addition, there are no wet weather restrictions for native surfaced roads and 

trails that intersect suitable great gray owl meadows.

The remaining action alternatives reduces the impacts to great gray owl meadows by prohibiting cross 

country travel on between 16 and 20 meadows with existing unauthorized routes, totaling 5.3 to 5.9 miles.

Alternative 5 would benefit the least, and Alternative 3 would benefit the most from the proposed actions.

Alternative 5 proposes to add or reopen approximately 1⁄2 mile of motorized routes within 5 meadows, 

while the remaining action alternatives proposes to affect between 0 and 5 meadows from 0 to 0.1 mile of 

motorized route addition. This amount of impact to suitable great gray owl habitat should not limit the 

distribution of great gray owls in the future. 

For all the action alternatives, cross country travel would be prohibited on 3,165 great gray owl 

meadows, including approximately 6 miles on unauthorized routes within great gray owl meadows which 

would benefit great gray owl habitat. However, non-motorized use (hiking, mountain bicycling, 

equestrian, etc.) may occur on these routes. Some impacts to great gray owl foraging habitat may be 

expected from non-motorized use in the future. As these routes become revegetated and recover either 

through active or passive restoration efforts, overall impacts to great gray owl habitat would be expected 

to recover and diminish in the future.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 393

Table 3.03-110. Cumulative Effects (Great Gray Owl Suitable Sites) 

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Direct and Indirect effects of proposed alternatives

Proposed route additions (negative impact)1

Number of Suitable GGO Meadow Sites Intersected 21 3 0 1 4 5 2

Miles 5.93 0.05 0 0.02 0.27 0.09 0.04

Reopened ML 1 Roads

Number of Potential GGO Meadow Sites Intersected 0 0 0 0 2 0 0

Miles 0 0 0 0 0.21 0 0

Unauthorized routes prohibited to cross country travel (positive impact)2

Number of Suitable GGO Meadow Sites Intersected 0 17 20 18 16 16 18

Miles 0 5.97 5.93 5.72 5.44 5.83 5.89

Cumulative effects of past and present actions

Existing motorized routes - NFS lands (negative impact)

Number of Suitable GGO Meadow Sites Intersected 22 22 22 22 22 22 22

Miles 6.06 6.06 6.06 6.06 6.06 6.06 6.06

Existing routes on private land - non-NFS lands (negative impact)

Number of Suitable GGO Meadow Sites Intersected 5 5 5 5 5 5 5

Miles 0.80 0.80 0.80 0.80 0.80 0.80 0.80

Existing non-motorized routes (negative impact)

Number of Suitable GGO Meadow Sites Intersected 5 5 5 5 5 5 5

Miles 1.22 1.22 1.22 1.22 1.22 1.22 1.22

Decommissioned routes (positive impact)

Number of Suitable GGO Meadow Sites Intersected 2 2 2 2 2 2 2

Miles 0.47 0.47 0.47 0.47 0.47 0.47 0.47

Roads closed by previous NEPA decisions, pending implementation (positive impact)

Number of Suitable GGO Meadow Sites Intersected 2 2 2 2 2 2 2

Miles 0.36 0.36 0.36 0.36 0.36 0.36 0.36

Total Cumulative Effects

Number of Times GGO Meadows Intersected by Routes 53 35 32 33 38 37 34

Total Miles 14.0 8.1 8.08 8.10 8.56 8.17 8.12

1 Alternative 1 includes the existing unauthorized routes, while all action alternatives include proposed motorized routes.

2 Includes routes unauthorized to motorized public use (both system and unclassified).

Overall Cumulative Effects from Past, Present, and

Reasonably Foreseeable Actions

Cumulative impacts to the great gray owls include past, present, and future impacts from livestock 

grazing, timber harvest, roads, and recreational activities. Appendix H (Reasonably Foreseeable Projects 

and Cumulative Effects) provides a list and description of past, present, and reasonably foreseeable 

projects on private lands within the Tahoe NF boundary. Some, but not all, of these activities would 

contribute to impacts to the great gray owl within the cumulative effects boundary. 
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394 – Tahoe National Forest

Between 1994 and 2008, several wildfires resulted in burning over 10,000 acres of old forest habitat

(CWHR 4M, 4D, 5M, 5D, and 6). Since 1990, more than 130,000 acres of vegetation management 

activities have occurred on the Tahoe NF. Some, but not all have resulted in impacts to great gray owl 

nesting habitats. Between 2001 and 2008, about 17,000 acres of forest vegetation and fuels thinning and 

mastication projects were completed, which were designed to reduce the risk of additional habitat loss to 

wildfires. These treatments generally do not result in habitat removal, but may result in habitat quality 

changes. Between 1960 and present, private land harvest within the boundaries of the Tahoe NF has 

resulted in over 87,000 acres of vegetation treatments including clearcuts, sanitation, shelterwood, and 

thinning. Much of the private land harvest has resulted in the loss or reduction in spotted owl habitat.

These wildfires and vegetation treatment projects may have resulted in a reduction in some great gray 

owl nesting habitat on the Tahoe NF since 1960. 

Thinning projects designed to reduce hazardous fuels will continue to be the primary activity

affecting forested habitat on the Tahoe (see Appendix H, Reasonably Foreseeable Projects and 

Cumulative Effects). Although these treatments may reduce habitat quality (i.e. nesting habitat reduced to 

foraging habitat), it expected that suitable habitat would be maintained, and it is anticipated that these 

treatments would reduce the amount of forested habitat potentially lost from future stand replacing 

wildfires (USDA Forest Service 2004). The California Department of Forestry and Fire Protection 

currently lists approximately 12,000 acres of private land within the Tahoe NF administrative boundary 

for which timber harvest plans have been submitted. Timber harvest on private lands is generally more 

intensive and does not typically maintain habitat in a suitable condition for great gray owls.

Historic livestock grazing has impacted montane meadows and is considered to be a primary factor 

that has influenced montane meadow habitat for birds in the Sierra Nevada (Graber 1996, Green et al. 

2003, Menke et al. 1996). Many of the landbird species utilizing these meadows feed upon insects that 

decline in response to removal of this herbaceous growth (Graber 1996). Poorly managed grazing in 

riparian areas can impact nesting densities of many bird species, and particularly of habitat specialists 

such as the great gray owl, willow flycatcher, Lincoln’s sparrow, and white-crowned sparrow (RHJV 

2004). 

Current livestock grazing on active allotments may affect a number of suitable great gray owl 

meadow habitats on the Forest. However, standards and guidelines for grazing in the Sierra Nevada Forest 

Plan Amendment generally are designed to minimize grazing impacts and maintain montane meadow 

habitat in a suitable condition for great gray owls. Non-motorized trails allow for backcountry hiking, 

camping, and equestrian use which may occur in meadows not accessed by motorized routes, and can 

adversely affect additional meadow habitat or disturb species. These activities are generally dispersed and 

of low impact to habitat. Foreseeable future projects listed in the Tahoe Schedule of Proposed Actions do 

not indicate additional effects. Perazzo Meadow on the Sierraville Ranger District, where great gray owl 

detections have been documented, is currently underway for watershed restoration efforts to improve the 

hydrologic and vegetation conditions that would benefit great gray owl foraging conditions.

Urban development and encroachment into the Sierra foothills continues to be a concern and could be 

a cumulative impact to great gray owls, especially considering the checkerboard ownership pattern and 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 395

accessibility of the Tahoe NF landscape. Great gray owls are rare and attract the attention of many 

professional and amateur bird watchers alike. These avid birders hoping to catch a glimpse of the elusive 

species may unintentionally disturb and cause harm to individual birds which could affect reproductive 

status and ultimately affect the abundance and distribution of this very rare species. 

Alternative 1 poses the greatest cumulative risk to suitable great gray owl foraging habitat where 

these suitable great gray owl meadows are intersected by a motorized or non-motorized route on both 

NFS and non-NFS lands 53 times for a total of 14 miles. Continued motorized route proliferation in the 

future could alter meadow vegetation and hydrology that would impact habitat conditions for great gray 

owl prey species in the long term, and could adversely affect the potential for great gray owls to occupy 

these sites in the near and distant future. In addition, there are no wet weather restrictions for native 

surfaced roads and trails that intersect suitable great gray owl meadows.

Sensitive Species Determination

The Biological Evaluation for the Tahoe NF Motorized Travel Management Project EIS, which is hereby 

incorporated by reference, determined that the action alternatives may affect great gray owl, but is not 

likely to result in a trend toward Federal listing or loss of viability for this species within the planning 

area of the Tahoe National Forest. In the absence of a range wide viability assessment, this viability 

determination is based on local knowledge of this species as discussed previously in this evaluation, and 

professional judgment.

Incidental great gray owls have been detected on the Sierraville Ranger District and on private land 

adjacent to NFS lands within the boundary of the Tahoe NF on the west side of the Forest. The addition of 

motorized routes to the NFTS would not directly, indirectly or cumulative affect known locations of great 

gray owls since no motorized route additions are proposed in the vicinity of the documented owl sightings

that would potentially disturb them.

Alternative 6, the Preferred Alternative, would result in less than 0.1 mile intersecting suitable great 

gray owl meadow sites within 5 of 41 suitable great gray owl meadow sites across the Tahoe NF. This 

amount of habitat affected by motorized routes would pose a relatively low risk to great gray owl 

breeding habitat.

Compliance with Forest Plan and Other Direction

The Tahoe NF LRMP as amended by the SNFPA ROD (2004) provides management direction to establish 

and maintain Protected Activity Centers (PACs) to include the forested area and adjacent meadow around 

all known great gray owl nest stands. The desired condition for meadow vegetation in great gray owl 

PACs supports a sufficiently large meadow vole population to provide a food source for great gray owls 

through the reproductive period. Although the Tahoe NF does not currently support known great gray owl 

nesting pairs, potentially suitable great gray owl meadows were analyzed to determine potential impacts 

from the Tahoe NF Travel Management Project.

In addition the Tahoe NF LRMP provides management direction for managing meadows, wetlands, 

and Riparian Conservation Areas that are applicable to suitable great gray owl meadow as follows:
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396 – Tahoe National Forest

• Locate roads away from meadow edges where alternative routes are available (Tahoe LRMP)

(Management Standard & Guideline).

• Avoid wetlands or minimize effects to natural flow patterns in wetlands and avoid road 

construction in meadows.

• Evaluate new proposed management activities within CARs and RCAs during environmental 

analysis to determine consistency with the riparian conservation objectives (RCOs) at the project 

level and the AMS goals for the landscape. Ensure that appropriate mitigation measures are 

enacted to (1) minimize the risk of activity-related sediment entering aquatic systems and (2) 

minimize impacts to habitat for aquatic- or riparian-dependent plant and animal species 

(Management Standard & Guideline 92).

• Maintain and restore the hydrologic connectivity of streams, meadows, wetlands, and other special 

aquatic features by identifying roads and trails that intercept, divert, or disrupt natural surface 

and subsurface water flow paths. Implement corrective actions where necessary to restore 

connectivity (RCO#2, Management Standard & Guideline 100).

In the above sections, the Proposed Action and alternatives for the Tahoe NF Motorized Travel 

Management Project were analyzed for their potential effects to great gray owl meadows which address

the above management standard and guidelines as they apply to great gray owl habitat. Mitigation 

measures for the action alternatives to minimize the risk of sediment and streambank alteration from 

proposed motorized route additions and existing unauthorized routes are addressed in the RCO analysis 

and Appendix A (Site Specific Road, Trail and Open Area Information). 

Alternative 1 is least consistent with the above standards and guidelines for managing meadows in 

terms of maintenance and hydrologic connectivity of meadows, avoidance of roads near and within 

meadows, and minimizing effects to meadow condition and function. Alternative 1 continues cross 

country travel, including within 21 great gray meadows on approximately 6 miles of existing 

unauthorized routes.

All of the action alternatives are consistent with the Standards and Guidelines since they reduce the 

potential effects to great gray owl meadows. All the action alternatives would prohibit cross country travel 

on 3,185 great gray owl meadow acres, and reduces the impacts of 16 to 20 great gray owl meadows 

(Alternative 5 reduces the least, Alternative 3 reduces the most) from 5.4 miles to 6 miles of existing 

routes unauthorized to motorized public use. All the action alternatives considerably improve meadow 

function and connectivity for the great gray owl, since the project design standards were developed to 

minimize impacts to meadows and riparian habitat through the implementation of wet weather seasonal 

restrictions, and the prohibition of cross country travel.

Greater Sandhill Crane: Affected Environment

Introduction: The greater sandhill crane is a California State Threatened species and is listed as Sensitive 

on the Region 5 Forester’s Sensitive Species List (USDA Forest Service 1998). California pairs of 

sandhill cranes generally nest in wet meadow, shallow lacustrine, and fresh emergent wetland habitat, 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 397

with nests constructed of large mounds of water plants over shallow water (Zeiner et al. 1990, California 

Department of Fish and Game 1994). Studies in California during 1988 showed water depths averaging 

2.3 inches (California Department of Fish and Game 1994). Open meadow habitats are also used 

(Littlefield 1989). On dry sites, nests are scooped-out depressions lined with grasses (Zeiner et al. 1990). 

In the Tahoe National Forest, a breeding population of approximately 12 pair occurs within Carman 

Valley, Kyburz Flats, and Perazzo Meadow on the Sierraville Ranger District (Tahoe NF Biological 

Evaluation). In addition, sandhill cranes are known to breed in the Sardine Valley area on private land 

north of Stampede Reservoir.

Disturbance and/or Mortality from vehicles: Road and trail-associated factors can disrupt sandhill 

breeding activities which can ultimately cause a loss in productivity. Motorized activities off of roads and 

trails during the breeding season can cause direct mortality of young sandhill cranes. 

Habitat Degradation: routes across meadow sites can also indirectly affect sandhill cranes by 

damaging or degrading meadow or wetland habitat required for breeding.

Greater Sandhill Crane: Environmental Consequences

Indicators used to Measure Effects

Cross Country Travel. The prohibition of cross country travel is analyzed for their effects to sandhill 

crane breeding habitat.

Establishment of “Open Areas”: The establishment of the Stampede Reservoir “Open Area” is 

analyzed for the potential to affect Sandhill cranes. Establishment of “Open Areas” at Boca and Prosser 

Reservoir and Greenhorn Area would not affect Sandhill crane, since the sandhill crane habitat does not 

occur there and is not known to nest at these sites.

Additions to the NFTS: Sandhill crane breeding sites were analyzed to determine the number of 

miles of motorized route additions to the NFTS that intersects sandhill crane breeding sites.

Change in Class of Vehicles: The changes in class of vehicle was analyzed for their potential to 

affect sandhill crane breeding habitat, since this action potentially changes the condition of the existing 

road surface from smoothed surfaced to rough surfaced; which could potentially alter meadow condition 

where routes intersect or are within close proximity to motorized routes.

Wet weather seasonal restrictions: Wet weather seasonal restrictions on native surfaced roads and 

motorized trails are analyzed for their potential to benefit sandhill cranes for each of the alternatives.

Reopened ML 1 Roads: Reopened ML 1 Roads are analyzed for their potential to benefit sandhill 

cranes for each of the alternatives.

Direct and Indirect Effects

Cross Country Travel

Cross country travel is not prohibited under Alternative 1, at Kyburz Flat, Carman Valley, and Perazzo 

Meadow where unmanaged cross country travel may impact breeding sandhill cranes where breeding 

productivity could be at risk from disturbance of motorized activity. All the action alternatives would 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

398 – Tahoe National Forest

prohibit cross country travel, and therefore, would benefit sandhill cranes at Kyburz Flat, Carman Valley, 

and Perazzo Meadow.

Breeding Sites Intersected by Motorized Route Additions to the NFTS 

On the Tahoe NF, three sandhill crane breeding sites are located at Kyburz Flat, Carman Valley, and 

Perazzo Meadow on the Sierraville Ranger District. For all the action alternatives, motorized routes added 

to the NFTS would not intersect known breeding sites at Kyburz Flat or Carman Valley on NFS lands, 

and therefore, no direct or indirect effects would occur from the addition of motorized routes to the 

NFTS.

Establishment of “Open Areas”

Stampede Reservoir “Open Areas”: Alternatives 2 and 6 propose to establish “Open Areas” for

motorized access to the shoreline below the high water mark on dry soils to allow for recreational fishing, 

water play, etc. Sandhill cranes have been documented to occur on the north shore of Stampede Reservoir, 

but nesting has not been documented in this area. However, a known breeding population of sandhill 

cranes occurs at Sardine Valley on private land just north of Stampede Reservoir. Motorized access to the 

shoreline could potentially disturb sandhill cranes using the area north of Stampede Reservoir. Under 

Alternative 1 cross country travel would continue, where the potential to disturb sandhill cranes may 

occur, including the Stampede Reservoir area. The remaining action alternatives do not allow access to 

these reservoirs, and therefore, sandhill cranes would not be directly disturbed by motorized use adjacent 

to Stampede Reservoir.

Changes to the NFTS

Change in Class of Vehicle. The change in class of vehicles would potentially affect sandhill crane 

habitat under Alternatives 2, 5, and 7 within Carman Valley (Knutsen Meadow), where different 

maintenance standards could result in changes to road surface type and potentially increase erosion and 

sedimentation risk. In general, it is not expected that the change in class of vehicle would result in a 

significant change to sandhill crane habitat conditions, since the road through Carman Valley is already 

rough surfaced. In the long term, road condition could deteriorate and cause localized effects. Since 

Carman Valley recently underwent major meadow restoration efforts including a culvert improvement 

project specifically designed to enhance meadow condition, any adverse effects of road maintenance 

changes would likely be minimal, especially considering that Carman Valley is a large meadow system 

and the road condition is currently stable. None of the other sandhill crane breeding sites are affected by 

the change in class of vehicles. 

Wet Weather Seasonal Restrictions. Wet weather seasonal restrictions on native surfaced roads and 

motorized trails would likely benefit sandhill cranes at Kyburz Flat and Carman Valley under Alternatives 

4, 5, and 6, since motorized use on native surfaced routes adjacent to Kyburz and Carman Valley breeding 

sites would be prohibited during the wet weather season. The prohibition of motorized use on these routes 

during the wet season would prevent the potential for meadow habitat degradation through vegetation and 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 399

soil loss at sandhill crane breeding sites. For the remaining alternatives, sandhill crane breeding sites at 

Carman Valley, Kyburz Flat, and Perazzo Meadow could be subject to an increase in the risk of meadow 

vegetation degradation through the loss of riparian vegetation and soil erosion from motorized use during 

the wet weather season, particularly in the spring months after snowmelt (April to early June).

Reopened ML 1 Roads: None of the alternatives proposes to reopen any ML 1 roads within or 

adjacent to sandhill crane habitats at Kyburz, Carman Valley, or Perazzo Meadow. Therefore sandhill 

cranes or their nesting habitat would not be directly or indirectly affected by this action.

Summary of Direct and Indirect Effects

Table 3.03-111 summarizes the overall net direct and indirect effect of the proposed actions from 

motorized route additions to the NFTS, prohibition of cross country travel, wet weather restrictions, and 

seasonal closures.
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400 – Tahoe National Forest

Table 3.03-111. Sandhill Crane - Summary of Overall Net Direct and Indirect Effects of the Alternatives

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country 

Travel 

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Nesting habitat 

at Kyburz, 

Carman Valley, 

and Perazzo 

Meadow

Cross Country 

Travel Continued 

Cross country 

travel prohibited

Cross country 

travel prohibited

Cross country 

travel prohibited

Cross country 

travel prohibited

Cross country 

travel prohibited

Cross country 

travel prohibited

Establishment

of “Open 

Areas”

Trend of Effect Negative Negative No Effect No Effect No Effect No Effect No Effect

Stampede 

Reservoir (no 

effect at all 

other “Open 

Areas”)

Unmanaged 

shoreline access 

continued

Open motorized 

access to 

Stampede on dry 

soil, including 

north shore 

where sandhill 

cranes observed

No motorized 

access to 

shoreline

No motorized 

access to 

shoreline

No motorized 

access to 

shoreline

No motorized 

access to 

Stampede 

Reservoir at 

known sandhill 

crane location at 

north shore of 

Stampede

No motorized 

access to 

shoreline

Motorized route 

additions

Trend of Effect Negative No Effect No Effect No Effect No Effect No Effect No Effect

Miles Unauthorized 

routes continue

0 0 0 0 0 0

Changes to the 

NFTS

Wet Weather 

Restrictions

No effect No effect No effect Positive benefit 

to habitat 

Positive benefit 

to habitat 

Positive benefit 

to habitat

No effect

Change in Class 

of Vehicles

No effect Localized 

negative effects

at Carman 

Valley due to 

maintenance 

level 

downgrades.

No effect No Effect Localized 

negative effects

at Carman 

Valley due to 

maintenance 

level 

downgrades 

No Effect Localized 

negative effects

at Carman 

Valley due to 

maintenance 

level 

downgrades.

Reopened ML 1 

Roads

No Effect No Effect No Effect No Effect No Effect No Effect No Effect.

Amendments to Forest Plan No Effect No Effect No Effect No Effect No Effect No Effect No Effect
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 401

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Overall Net Effect of Proposed 

Actions

Negative effect 

to habitat where 

cross country 

travel continued.

Least beneficial 

to habitat from

adverse effects 

of “open area” 

establishment at 

Stampede Res.

2nd most 

beneficial to 

habitat (shared 

with Alts 5 & 7) 

due to 

prohibition of 

cross country 

travel.

Most Beneficial 

to habitat 

(shared with Alt 

6) due to 

prohibition of 

cross country 

travel, with 

added benefits 

from wet 

weather 

restrictions.

2nd most 

beneficial to 

habitat (shared 

with Alts 2 & 7) 

due to 

prohibition of 

cross country 

travel, with 

added benefits

from wet 

weather 

restrictions.

Most beneficial 

to habitat 

(shared with Alt 

4) due to 

prohibition of 

cross country 

travel, with 

added benefits 

from wet 

weather 

restrictions.

2nd most 

beneficial to 

habitat (shared 

with Alts 3 & 5) 

due to 

prohibition of 

cross country 

travel.

*Alternative 1 includes existing unauthorized routes that would continue with cross country travel, while all the action alternatives include proposed route additions.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

402 – Tahoe National Forest

Cumulative Effects

Spatial and Temporal Cumulative Effects Boundary 

Breeding sandhill cranes are known to breed at three sites on the Tahoe NF, at Kyburz Flat and Carman 

Valley - all are located on the eastside of the Forest on the Sierraville Ranger District. A fourth breeding 

site is located on private land in Sardine Valley just to the north of Stampede Reservoir. Therefore, the 

cumulative effects of the alternatives are analyzed in the vicinity of these four sites because they represent 

the spatial extent of breeding sandhill cranes on the Tahoe NF. Past and reasonably foreseeable 

cumulative impacts are analyzed within 20 years in the past and out 20 years into the future. This 

represents a reasonable timeframe for analyzing cumulative impacts since any longer timeframe for 

analyzing cumulative project impacts may be uncertain and speculative.

Cumulative Effects of Additions to the NFTS, Establishment of “Open Areas,” Prohibition of Cross 

Country Travel, Wet Weather Restrictions, and Change in Class of Vehicles

For Alternative 1, unmanaged cross country travel in the future may impact breeding sandhill cranes 

where breeding productivity could be at risk from disturbance of motorized activity. The rate of increased 

OHV use on the Tahoe NF is expected to increase in the future. All the action alternatives would prohibit 

unmanaged cross country travel, and therefore, would not likely contribute to existing cumulative impacts 

in the future and potentially benefit sandhill cranes. However, under both Alternative 1 and 2, cumulative 

adverse impacts could be added at Stampede Reservoir, adjacent to a known breeding population of 

sandhill crane on private land at Sardine Valley.

Overall Cumulative Effects to Sandhill Crane from Past, Present

and Reasonably Foreseeable Actions

Past cumulative impacts for the four sandhill crane breeding sites at Carman Valley, Kyburz Flat, Perazzo 

Meadow, and Sardine Valley include historic grazing practices, meadow vegetation and hydrologic 

function impacts from roads, railroad logging, diversions, past timber harvest practices, and recreational 

activities. A list of recent past, present, and future projects is provided in Appendix H (Reasonably 

Foreseeable Projects and Cumulative Effects). Some, but not all of these projects may have impacts to the 

sandhill crane. Current grazing standards and guidelines as directed in the Sierra Nevada Forest Plan 

Amendment Record of Decision (2004) are designed to minimize impacts to riparian resources from 

grazing. Some conifer encroachment into these sites has occurred from the lack of fires in the past 100 

years. Recent and future vegetation management and fuels reduction projects are designed to prevent the 

loss of forested habitat from large-scale, stand replacing catastrophic fire events.

Carman Valley

The Carman Valley area is currently recovering from a recent series of large-scale watershed restoration 

efforts to restore a highly degraded stream and riparian system using the plug and pond method. Prior to 

recent restoration efforts, numerous past attempts at improving watershed conditions were made dating 

back to the early part of the century, but were largely ineffective. The Carman Valley area falls within the 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 403

Beckwourth Peak Allotment which is grazed by sheep. Additional and ongoing restoration efforts will 

continue to improve riparian resources and watershed conditions, which will enhance breeding habitat for 

the sandhill crane.

Kyburz Flat

Kyburz Flat located east of Highway 89 north of Truckee, CA receives high recreational use from 

snowmobile use and cross country travel. The Kyburz Flat area was a part of the Boca, Kyburz, Sagehen, 

and Summit Allotment Management Plan (BKSS) where grazing management planning would reduce 

grazing impacts from sheep and improve riparian resource condition, and therefore, benefit breeding 

sandhill crane habitat at Kyburz Flat.

Perazzo Meadow

Perazzo Meadow is located on the Sierraville RD within the Perazzo Meadows Livestock Grazing 

Allotment. During the last 15 to 20 years, a variety of management efforts have been undertaken to 

improve riparian conditions and to reduce impacts from livestock grazing at Perazzo Meadows, including 

reducing livestock numbers, developing interim grazing management strategies, small watershed 

restoration efforts (structures), and others. Watershed degradation at Perazzo Meadows can be attributed 

not only to livestock grazing, but also to off-highway activities, loss of a bridge during the 1997 storm 

event, and other factors. Efforts to improve riparian watershed condition are currently underway, 

including through partnerships with local watershed groups, development of a grazing allotment 

management plan, and large-scale, watershed restoration efforts.

Sensitive Species Determination 

The Biological Evaluation for the Tahoe NF Motorized Travel Management Plan, which is hereby 

incorporated by reference, made a determination that the all the action alternatives may impact sandhill 

cranes, but are not likely to lead to a trend toward federally listing, and do not contribute to a downward 

trend for sandhill crane population viability.

Compliance with Forest Plan and other Direction

The Tahoe NF LRMP, as amended by the SNFPA ROD (2004), provides management direction for 

managing meadows, wetlands and riparian habitats, and Riparian Conservation Areas that are applicable 

to sandhill crane habitat as follows:

• Locate roads away from meadow edges where alternative routes are available (Tahoe LRMP)

(Management Standard & Guideline ). 

• Avoid wetlands or minimize effects to natural flow patterns in wetlands and avoid road 

construction in meadows.

• Evaluate new proposed management activities within CARs and RCAs during environmental 

analysis to determine consistency with the riparian conservation objectives (RCOs) at the project 

level and the AMS goals for the landscape. Ensure that appropriate mitigation measures are 

enacted to (1) minimize the risk of activity-related sediment entering aquatic systems and (2) 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

404 – Tahoe National Forest

minimize impacts to habitat for aquatic- or riparian-dependent plant and animal species 

(Management Standard & Guideline 92).

• Maintain and restore the hydrologic connectivity of streams, meadows, wetlands, and other special 

aquatic features by identifying roads and trails that intercept, divert, or disrupt natural surface 

and subsurface water flow paths. Implement corrective actions where necessary to restore 

connectivity (RCO#2, Management Standard & Guideline 100).

In the above sections, the Proposed Action and alternatives for the Tahoe NF Motorized Travel 

Management Project were analyzed for their potential effects to sandhill crane breeding habitat which 

addresses the above management standard and guidelines as they apply to sandhill crane breeding habitat. 

Mitigation measures for the action alternatives to minimize the risk of sediment and streambank alteration 

from proposed motorized routes and existing unauthorized are addressed in the RCO analysis and 

Appendix A (Site Specific Road, Trail and Open Area Information). 

Alternative 1 is least consistent with the above standards and guidelines for managing meadows in 

terms of maintenance and hydrologic connectivity of meadows, avoidance of roads near and within 

meadows, and minimizing effects to meadow condition and function. Alternative 1, continues cross 

country travel, including within Kyburz Flat, Perazzo Meadows, and Carman Valley (Knutsen Meadow) 

(known sandhill crane breeding sites).

All of the action alternatives are consistent with the above standards and guidelines since they reduce 

the impacts to sandhill cranes. The action alternatives all prohibit cross country travel on all three sandhill 

crane breeding sites, and reduces the impacts to these meadows. No motorized route additions to the 

NFTS are proposed within any sandhill crane breeding areas. Alternative 2 proposes changes in class of 

vehicles to a road that is adjacent to Knudsen Meadow, where small, localized effects may result from 

different maintenance standards.

Yellow Warbler: Affected Environment

The yellow warbler was selected as the MIS for riparian habitat in the Sierra Nevada. The Sierra Nevada 

Forest MIS Report and the Tahoe NF Motorized Project-level MIS Report are incorporated by reference. 

The yellow warbler is usually found in riparian deciduous habitats in summer (cottonwoods, willows, 

alders, and other small trees and shrubs typical of low, open-canopy riparian woodland) (CDFG 2005). 

Yellow warbler is dependent on both meadow and non-meadow riparian habitat in the Sierra Nevada 

(Siegel and DeSante 1999). On the Tahoe NF, CWHR montane riparian habitat (MRI) provides suitable 

habitat for the yellow warbler.

Disturbance from Vehicles: road and trail associated factors can disrupt warbler breeding activities, 

which can ultimately cause a loss in breeding activity. 

Habitat Degradation: motorized routes across meadow and riparian habitat can indirectly affect 

yellow warblers by damaging or degrading or meadow montane riparian habitat required for breeding.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 405

Yellow Warbler: Environmental Consequences

Habitat Factor(s) for the Analysis: The habitat factor used to assess direct and indirect effects of 

motorized routes for the yellow warbler were montane riparian habitat acres affected by motorized route 

additions to the NFTS. Habitat acres were determined by the length of the route multiplied by the width 

of the route. Route width is assumed to be a maximum of 8 feet. In some cases, route width may be less;

therefore, impacts may be somewhat over-emphasized.

Current Condition of the Habitat Factor(s) in the Project Area: The Tahoe NF has approximately 

5,131 acres CWHR montane riparian habitat (MRI).

Direct and Indirect Effects to Habitat

Cross Country Travel. Under Alternative 1, cross country travel would continue, potentially affecting 

3,525 acres of montane riparian habitat (~5 acres directly affected by continued use on existing 

unauthorized routes), potentially causing reduced habitat effectiveness through disturbance, avoidance, 

and abandonment for the yellow warbler. For the action alternatives, cross country travel would be 

prohibited on 3,525 acres, where disturbance, avoidance, abandonment would be reduced or eliminated. 

Of these 3,525 acres, approximately 5 acres of yellow warbler habitat would directly benefit of the 

prohibition of cross country travel on existing unauthorized routes.

Additions to the NFTS. Table 3.03-112 displays the acres of montane riparian habitat directly and 

indirectly affected by the alternatives. Alternative 1 affects the greatest amount of montane riparian 

habitat, suitable for yellow warbler, where unauthorized routes would result in a loss or reduction in 

montane riparian habitat within about 5 out of 5,131 acres or 0.1% of Tahoe NF montane riparian habitat. 

The action alternatives all reduces overall impacts to yellow warbler habitat by eliminating cross country 

travel on existing unauthorized routes that potentially may degrade yellow warbler habitat. Alternative 6 

would benefit yellow warbler habitat the least, where motorized route additions would affect 

approximately 0.5 acre out of 5131 acres yellow warbler habitat on the Tahoe NF. The majority of 

proposed route additions (9 of 11) under Alternative 6 are short spur routes which access dispersed 

recreation areas. Alternatives 2, 4, 5, and 7 would result in minimal local effects to montane riparian 

habitat, where motorized route additions would result in less than 0.2 acres of 5,131 acres or 0.003% of 

Tahoe NF yellow warbler habitat. Alternative 3 does not propose motorized additions within or adjacent 

to yellow warbler habitat, and therefore would not affect any montane riparian habitat.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

406 – Tahoe National Forest

Table 3.03-112. Proportion of Yellow Warbler MIS habitat affected by Motorized Route Additions

Yellow Warbler MIS 

Habitat 

Yellow 

Warbler 

Habitat Acres

Alt1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Acres Montane Riparian Habitat 4.96 0.16 0.00 0.16 0.17 0.49 0.16

Proportion of Sierra 

Nevada Habitat 

29,000 0.017% 0.001% 0% 0.001% 0.001% 0.002% 0.001%

Habitat Security Risk in Sierra Nevada Low Low Low Low Low Low Low

Proportion of Tahoe NF 

Habitat

5,131 0.09% 0.003% 0% 0.003% 0.003% 0.01% 0.003%

Habitat Security Risk in Tahoe NF Low Low Low Low Low Low Low

*

Alternative 1 includes existing unauthorized routes associated with cross country travel. 

Change in Class of Vehicles. The change in class of vehicle on some existing NFTS motorized roads 

may result in some smoothed surfaced roads becoming rough surfaced roads through changed road 

maintenance. In addition, some existing motorized NFTS roads may different maintenance resulting in 

increased vegetation density at the road margins which would provide additional cover and/or foraging 

habitat. The resulting roadway condition would depend upon the amount and type of vegetation present 

and the type of maintenance any given road receives. For the yellow warbler, existing habitat conditions 

will dictate whether or not the change in class of vehicle will result in reduced habitat quality. In general, 

it is not expected that the change in class of vehicle would result in a significant change to yellow warbler 

habitat conditions, unless changed road maintenance results in increased montane riparian habitat 

degradation.

Wet Weather Seasonal Restrictions. Alternatives 4, 5, and 6 would impose wet weather seasonal 

restrictions on all native surfaced roads and motorized trails, where montane riparian habitats for the 

yellow warbler would be benefited through the reduction of erosion and sedimentation that could occur 

from wet season motorized use on routes, especially motorized routes that are within close proximity to 

yellow warbler habitat. Alternatives 1, 2, 3, and 7 do not impose wet seasonal weather restrictions on 

native surfaced motorized routes and therefore, yellow warbler habitat would not benefit from wet 

weather seasonal restrictions. Alternative 1 has the greatest number of stream crossings and highest RCA 

route densities that could potentially delivery sediment to montane riparian habitats from motorized use 

on native surfaced routes during the wet weather season.

Reopened ML 1 Roads. Except for Alternative 5, none of the alternatives proposes to reopen any ML 

1 roads within yellow warbler habitat, and therefore would have no effect to yellow warbler habitat.

Alternative 5 would only affect a very small proportion of yellow warbler habitat (less than 0.1 ac) that 

would not alter the trend in yellow warbler habitat at either the bioregional or Forest-wide scale (Table 

3.03-113).
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 407

Table 3.03-113. Proportion of Yellow Warbler MIS habitat affected by Reopened ML 1 Roads

Yellow Warbler MIS Habitat Yellow Warbler 

Habitat Acres

Alt 1, 2, 3, 4, 6, 7 Alt 5

Acres Montane Riparian Habitat 0 0.07

Proportion of Sierra Nevada Habitat 29,000 0% 0.0002%

Habitat Security Risk in Sierra Nevada None None

Proportion of Tahoe NF Habitat 5,131 0% 0.001%

Habitat Security Risk in Tahoe NF None None

Summary of Direct and Indirect Effects 

Table 3.03-114 summarizes the overall net effect to the yellow warbler habitat from the motorized route 

additions to the NFTS, prohibition of cross country travel, wet weather restrictions, and seasonal closures. 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

408 – Tahoe National Forest

Table 3.03-114. Yellow Warbler Montane Riparian Habitat - Summary of Overall Net Direct and Indirect Effects

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres Prohibited 0 3,525 3,525 3,525 3,525 3,525 3,525

Motorized Route Additions to the NFTS

Trend of Effect Negative Small localized 

effects

No Effect Small localized 

effects

Small localized 

effects

Small localized 

effects, mostly

from routes to 

dispersed 

recreation 

areas

Small localized 

effects

Acres Affected 4.96 0.16 0.00 0.16 0.18 0.49 0.16

Establishment of “Open Areas” No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Changes to 

the NFTS

Wet Weather Restrictions No Effect No Effect No Effect Positive Benefit 

to habitat.

Positive Benefit 

to habitat.

Positive Benefit 

to habitat.

No effect

Change in Class of Vehicles No Effect Minor, localized 

negative effect

No Effect Minor, localized

negative effect

Minor, localized 

negative effect

Minor, localized 

negative effects

Minor, 

localized 

negative effect

Reopened ML 

1 Roads

Trend of 

Effect

No Effect No Effect No Effect No Effect Negative, small 

localized 

effects

No Effect No Effect

Acres 0 0 0 0 0.07 0 0

Amendments to the Forest Plan No Effect No Effect No Effect No Effect No Effect No Effect No Effect
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 409

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Overall Net Effect of Proposed Actions Negative –

Cross country 

travel 

continued on 

3,525 acres

and within 5.1

acres directly 

affected by 

unauthorized 

routes.

2nd most 

beneficial

alternative.

Cross country 

travel 

prohibited on 

3,525 acres 

and within 4.9 

acres directly 

affected by 

unauthorized 

routes; 

although minor 

negative 

impacts from 

route additions; 

overall reduces

disturbance 

and habitat 

fragmentation.

Most benefical

alternative.

Cross country 

travel 

prohibited on 

3,525 acres 

and within 5.1 

acres directly 

affected by 

unauthorized 

routes; overall 

reduces 

disturbance 

and habitat 

fragmentation..

3nd most 

beneficial

alternative, 

shared with Alt 

7. 

Cross country 

travel 

prohibited on 

3,525 acres 

and within 4.96 

acres directly 

affected by 

unauthorized 

routes; 

although minor 

negative 

impacts from 

route additions; 

overall reduces 

disturbance 

and habitat 

fragmentation.

4th most 

beneficial

alternative.

Cross country 

travel 

prohibited on 

3,525 acres 

and within 4.87 

acres directly 

affected by 

unauthorized 

routes; 

although minor 

negative 

impacts from 

route additions 

and reopened 

ML 1 roads; 

overall reduces 

disturbance 

and habitat

fragmentation

Least beneficial 

alternative.

Cross country 

travel 

prohibited on 

3,525 acres 

and within 4.6 

acres directly 

affected by 

unauthorized 

routes; 

although minor 

negative 

impacts from 

route additions; 

overall reduces 

disturbance 

and habitat 

fragmentation.

3rd most 

beneficial, 

shared with Alt 

4. 

Cross country 

travel 

prohibited on 

3,525 acres 

and within 4.96 

acres directly 

affected by 

unauthorized 

routes; 

although minor 

negative 

impacts from 

route additions; 

overall reduces 

disturbance 

and habitat 

fragmentation.

*Alternative 1 includes existing unauthorized routes that would continue with cross country travel, while all the action alternatives include proposed route additions.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

410 – Tahoe National Forest

Cumulative Effects to Habitat in the Analysis Area

Appendix H (Reasonably Foreseeable Projects and Cumulative Effects) provides a list and description of 

past, present, and reasonably foreseeable projects on NFS and private lands within the Tahoe NF 

boundary. Some, but not all, of these activities have or will contribute to impacts to the montane riparian 

habitat for the yellow warbler within the Tahoe NF boundary. Since 1990, more than 130,000 acres of 

vegetation management activities have occurred on the Tahoe NF. Generally, vegetation/fuels 

management projects have not affected habitat within montane riparian habitats. Between 2001 and 2007, 

over 13,000 acres of forest vegetation and fuels projects were completed, which primarily thinned, 

masticated, and/or burned vegetation to reduce the potential for catastrophic wildfires. Many recent, 

current, and future vegetation and fuels reduction projects are designed to minimize effects to montane 

riparian habitats by following “riparian conservation objectives” as prescribed in the Sierra Nevada Forest 

Plan Amendment Record of Decision (2004). Between 1994 and 2008, approximately 94,000 acres 

burned on the Tahoe NF, some of which have resulted in substantial changes in montane riparian habitat. 

In many cases, montane riparian habitat that was severely burned during a stand-replacing wildfire 

resulted in changes to or loss of riparian vegetation, loss of shade, cover, and structural diversity. In some 

cases, some riparian areas recovered post-fire and were significantly enhanced (i.e. aspen habitats in the 

Cottonwood Fire of 1994).

Currently, there is a high demand for recreational use on the Tahoe NF due to its close proximity to 

urban centers. The Tahoe NF provides a wide variety of recreational experiences including developed and 

dispersed camping, hiking, fishing, hunting, wildlife viewing, winter sports activities (downhill skiing, 

cross country skiing, snowmobiling), summer OHV use, and a variety of other non-motorized use 

(equestrian use and mountain biking). Recreational use on the Tahoe NF has significantly increased

compared to the past 20 to 30 years. Because of the proximity to urban areas and population growth, 

increased recreational use on the Tahoe NF is expected to continue to increase in the future including 

camping, hiking, fishing, wildlife viewing, hunting, and OHV use. Generally, the increase in recreational 

use on the Tahoe NF has the potential to cause an increased impact to montane riparian habitats because 

humans are attracted to these areas for their beauty and scenic quality. Future increase in recreational use 

on the Tahoe NF is expected, and therefore, increased impacts to montane riparian habitat would be 

expected, particularly during the summer months. Table 3.03-115 lists the reasonably foreseeable future 

projects and the associated direct, indirect, and cumulative impacts that are planned to occur on the Tahoe 

NF.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 411

Table 3.03-115. Direct, Indirect, and Cumulative Impact of Reasonably Foreseeable Future Projects

Project type Number of 

Projects

Direct and Indirect Impact to 

Yellow Warbler

Overall Cumulative Impact

Vegetation 

management/fuels 

reduction – thinning, 

group select, mastication

~30 Short-term disturbance from harvest 

activities only when adjacent to 

montane riparian yellow warbler 

habitat.

Long-term beneficial cumulative 

effects by reduced risk of habitat 

loss from high severity wildfires.

Aspen enhancement 8 Short-term disturbance during 

implementation.

Long-term cover and forage habitat 

improvement

Long-term beneficial cumulative 

effects from improved habitat 

conditions

Hazard tree removal 4 Minimal impact. Short-term 

disturbance during harvest if 

adjacent to montane riparian 

habitats.

None to minimal cumulative impact

Fish passage 

construction project

1 Short-term disturbance during 

project implementation.

No cumulative impact

Watershed Restoration 

(Carman II and Perazzo)

2 Short-term disturbance during 

implementation. Improve riparian 

and meadow habitat quality used 

for forage and reproduction.

Beneficial cumulative impact by 

improving long-term forage and 

nesting habitat conditions.

Special Use permit 

renewal

4 N/A administrative action None

Non-motorized Trail 

development

2 None None

Designate Energy 

Corridor

1 N/A programmatic administrative 

action

Unknown, site-specific cumulative 

impacts may occur depending on 

location of the corridor.

Cumulative Effects Conclusion

Alternative 1, no action, cumulatively affects the greatest amount of yellow warbler habitat (5 acres out of 

5,131 acres or 0.1%) on the Tahoe NF from continued use on unauthorized routes. All the action 

alternatives reduces overall cumulative effects of existing unauthorized routes within yellow warbler 

habitat, where cross country travel would be prohibited on between 4 1⁄2 to 5 acres. Alternative 6 would 

result in a loss or reduction in approximately 0.5 acres yellow warbler habitat, primarily from the addition 

of motorized routes which accesses dispersed recreation areas. Alternative 3 does not add to existing 

cumulative effects from motorized route additions.

The remaining action alternatives affect an insignificant amount of yellow warbler habitat from 

motorized route additions. Alternatives 2, 4, 5, and 7 would alter less than 0.003% of yellow warbler 

habitat (0.2 acres out of 5,131 acres Tahoe NF habitat). None of the alternatives would be expected to 

alter the trend in yellow warbler habitat from the addition of motorized routes or from reopening ML 1 

roads (Alt 5 only).

In general, it is not expected that the change in class of vehicle would result in a significant change to 

yellow warbler habitat conditions, unless changed road maintenance results in increased montane riparian 

habitat degradation for Alternatives 2, 4, 5, 6, and 7.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

412 – Tahoe National Forest

Wet weather seasonal restrictions on all native surfaced roads and motorized trails under Alternatives 

4, 5, and 6 would benefit montane riparian habitat for the yellow warbler through the reduction of erosion 

and sedimentation. Alternatives 1, 2, 3, and 7 do not impose wet seasonal weather restrictions on native 

surfaced motorized routes and therefore, montane riparian habitat for the yellow warbler would not 

benefit from wet weather seasonal restrictions. 

Finally, Alternative 1 would pose the greatest risk on 3,525 acres of yellow warbler habitat, where 

cross country travel would not be prohibited causing reduced habitat effectiveness through disturbance, 

avoidance, and abandonment for the yellow warbler. For the action alternatives, cross country travel 

would be prohibited on 3,525 montane riparian acres, where disturbance, avoidance, abandonment would 

be reduced or eliminated. Overall, none of the alternatives would alter the existing trend in yellow warbler 

habitat. However, Alternative 1, which allows cross country motorized travel to continue, could alter 

yellow warbler population trend.

Summary of Yellow Warbler Status and Trend at the Bioregional Scale. The Tahoe NF LRMP (as 

amended by the SNF MIS Amendment) requires bioregional-scale habitat and distribution population 

monitoring for the yellow warbler; hence, the riparian habitat effects analysis for the Tahoe NF Motorized 

Travel Management Project must be informed by both habitat and distribution population monitoring 

data. The sections below summarize the habitat and distribution population status and trend data for the 

yellow warbler. This information is drawn from the detailed information on habitat and population trends 

in the SNF Bioregional MIS Report (USDA Forest Service 2008), which is hereby incorporated by 

reference.

Habitat Status and Trend. There are currently 29,000 acres of riparian habitat on NFS lands in the 

Sierra Nevada. Within the last decade, the trend is stable.

Population Status and Trend. The yellow warbler has been monitored in the Sierra Nevada at 

various sample locations by avian point counts and breeding bird survey protocols, including Lassen NF 

(Burnett and Humple 2003, Burnett et al. 2005) and Inyo NF (Heath and Ballard 2003) point counts; ongoing California Partners in Flight monitoring and studies (CPIF 2004); 1992 to 2005 – Sierra Nevada 

Monitoring Avian Productivity and Survivorship (MAPS) stations (Siegel and Kaschube 2007); and 1968 

to present – BBS routes throughout the Sierra Nevada (Sauer et al. 2007). These data indicate that yellow 

warblers continue to be present at these sample sites, and current data at the range wide, California, and 

Sierra Nevada scales indicate that the distribution of yellow warbler populations in the Sierra Nevada is 

stable.

Relationship of Project-Level Habitat Impacts to Bioregional-Scale Yellow Warbler Trend. 

Alternative 1 would result in the greatest amount of suitable yellow warbler habitat (5 acres of 29,000 

acres or 0.02% of Sierra Nevada-wide habitat) affected by cross country travel, including use on existing 

unauthorized routes. The action alternatives would benefit yellow warbler habitat by prohibiting cross 

country travel, and result in less than 1 acre out of 29,000 Sierra Nevada yellow warbler habitat acres 

affected by motorized route additions or reopened ML 1 roads. Based on the insignificant percentage of 

yellow warbler habitat affected by the proposed alternatives, the Tahoe NF Motorized Travel 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 413

Management Project would not alter the existing habitat trend, nor would it lead to a change in the 

distribution of yellow warbler across the Sierra Nevada bioregion. 

Compliance with Forest Plan and Other Direction

The Tahoe NF LRMP, as amended by the SNFPA ROD (2004), provides management direction for 

managing meadows, wetlands and riparian habitats, and Riparian Conservation Areas that are applicable 

to yellow warbler habitat as follows:

• Locate roads away from meadow edges where alternative routes are available (Tahoe LRMP)

(Management Standard & Guideline). 

• Avoid wetlands or minimize effects to natural flow patterns in wetlands and avoid road 

construction in meadows.

• Evaluate new proposed management activities within CARs and RCAs during environmental 

analysis to determine consistency with the riparian conservation objectives (RCOs) at the project 

level and the AMS goals for the landscape. Ensure that appropriate mitigation measures are 

enacted to (1) minimize the risk of activity-related sediment entering aquatic systems and (2) 

minimize impacts to habitat for aquatic- or riparian-dependent plant and animal species 

(Management Standard & Guideline 92).

• Maintain and restore the hydrologic connectivity of streams, meadows, wetlands, and other special 

aquatic features by identifying roads and trails that intercept, divert, or disrupt natural surface 

and subsurface water flow paths. Implement corrective actions where necessary to restore 

connectivity (RCO#2, Management Standard & Guideline 100).

In the above sections, the Proposed Action and alternatives for the Tahoe NF Motorized Travel

Management Project were analyzed for their potential effects to yellow warbler montane riparian habitat 

which addresses the above management standard and guidelines as they apply to yellow warbler habitat. 

Mitigation measures for the action alternatives to minimize the risk of sediment and streambank alteration 

from motorized route additions to the NFTS and existing unauthorized routes are addressed in Appendix I 

(Riparian Conservation Objectives) and Appendix A (Site Specific Road, Trail and Open Area 

Information).

Alternative 1 is least consistent with the above standards and guidelines for managing montane 

riparian habitat in terms of maintenance and hydrologic connectivity of streams, meadows, and wetlands, 

avoidance of roads near and within meadows, and minimizing effects to montane riparian condition and 

function. Alternative 1 would continue cross country travel montane riparian habitats important to yellow 

warblers, including on 10 acres of montane riparian habitat resulting from travel on existing unauthorized 

routes.

All of the action alternatives are consistent with the above Standards and Guidelines. All the action 

alternatives would reduce the impacts to these habitats by prohibiting cross country travel on within 

yellow warbler habitats, including on about 41⁄2 to 5 acres of montane riparian habitat affected by existing 

unauthorized routes.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

414 – Tahoe National Forest

Aquatic Species and Habitat

Introduction

Various studies have demonstrated that sediment delivery to stream channels in a forested environment is 

correlated to road surface type, physical characteristics of the adjacent areas (e.g., litter depth, coarse 

wood), soils (erodibility), the steepness of slope below the road, and vehicle usage (Chin and others 2004 

In Guldin 2004, Clinton and Vose 2003). Other factors that contribute to in-channel sediment delivery 

include the number of stream crossings on a channel, the condition of the stream approach, and the road 

length draining into the stream channel crossing.

Indicators used to Measure Effects

Cross Country Travel: The prohibition of cross country travel is analyzed for the alternatives to estimate 

the potential effects to aquatic habitat factors from motorized cross country travel.

Additions to the NFTS: Measures or indicators of changes in sedimentation and water surface shade 

are assessed by analyzing the number of stream crossings additions associated with motorized route 

additions to the NFTS, and the miles motorized route additions within Riparian Conservation Areas 

(RCAs) for perennial and intermittent streams, and lakes, ponds, and reservoirs.

Establishment of “Open Areas”: The establishment of “Open Areas” at Greenhorn area and at 

Stampede, Boca, and Prosser reservoirs is analyzed for their effects to aquatic species.

Changes to the NFTS including Change in Class of Vehicles, Change in Season of Use, and 

Reopened Maintenance Level (ML) 1 Roads. 

• Change in Class of Vehicles: Changing the class of vehicle on a particular route potentially 

changes the impacts to soil and water resource due to changes in the road surface (i.e. from 

smooth surfaced to rough-surfaced) (see Chapter 3.02, Watershed Resources: Geology, Soil, 

Hydrology).

• Change in Season of Use: Proposed wet weather seasonal restrictions on native surfaced routes 

were analyzed for the alternatives in terms of all aquatic species and their habitats. Motorized 

travel on native surfaced routes during the wet weather season has the potential to cause erosion 

and deliver sediment to aquatic species habitats.

• Reopened ML 1 Roads: Reopened ML 1 roads are assessed for their potential effects aquatic 

species as motorized route additions are analyzed above.

Amendments to the Forest Plan: The removal of seasonal restrictions for wintering deer within the 

Humbug-Sailor Management Area 84 is analyzed for the potential effects to aquatic species.

Effects Common to All Aquatic Species

Establishment of Motorized “Open Areas”: Cross country travel would continue under Alternative 1 on 

at least 2,649 acres at Greenhorn and at Boca, Stampede, and Prosser reservoirs, where effects to aquatic 

species and their habitats would be adversely affected, including changes in water chemistry, increased 

temperature, changes to vegetation, and increased sedimentation and erosion. Only Alternatives 2 and 6 

propose to establish motorized “Open Areas.” The remaining action alternatives would not affect aquatic 

species.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 415

Alternative 2 proposes to establish 60 acres at Greenhorn and 2,589 acres at Boca, Stampede, and 

Prosser reservoirs. Alternative 2 would likely adversely affect important aquatic habitat conditions 

including water chemistry, temperature, and physical habitat at Greenhorn Creek. Since the “Open Areas” 

at the reservoirs are essentially under water during the wettest part of the year, no vegetation is present.

However, sedimentation could increase and affect water quality within the reservoirs, especially 

considering the entire circumference of the reservoirs would be opened to motorized use.

Alternative 6 does not propose establishing the Greenhorn area as an “Open Area,” and therefore, 

would not affect aquatic species. Alternative 6 proposes to establish 244 acres within discrete areas to 

provide motorized access on dry soils. Sedimentation and erosion should not be at an accelerated rate on 

the 244 acres designated “Open Areas” at Stampede, Prosser, and Boca reservoirs, since the proposed 

areas are stable and armored (Chapter 3.03-2). Generally, Alternative 6 benefits aquatic species habitats 

and improves existing conditions where currently the reservoirs are not prohibited to cross country 

motorized travel on at least 2,589 acres at the three reservoir areas.

Wet Weather Seasonal Closures: Proposed wet weather seasonal restrictions on native surfaced 

routes were analyzed for the alternatives in terms of all aquatic species and their habitats. Motorized 

travel on native surfaced routes during the wet weather season has the potential to cause erosion and 

deliver sediment to aquatic species habitats.

Alternatives 4, 5, and 6 would impose wet weather seasonal restrictions on all native surfaced roads 

and motorized routes, where fish and other aquatic species would be benefited through the reduction of 

erosion and sedimentation that could occur from wet season wheeled motorized use on routes, especially 

motorized routes that are within close proximity to or cross streams or other riparian aquatic habitats. 

Alternatives 1, 2, 3, and 7 do not impose wet weather seasonal restrictions on native surfaced motorized 

routes and therefore, aquatic riparian dependent species would not benefit from wet weather seasonal 

restrictions. Alternative 1 has the greatest number of motorized stream crossings and highest RCA route 

densities that could potentially delivery sediment to aquatic and riparian habitats from wheeled motorized 

use on native surfaced routes during the wet weather season.

Amendments to the Forest Plan: Changing the season of use by removing deer winter closures in 

Management Area 84 Humbug-Sailor would not likely affect aquatic species since wet weather seasonal 

restrictions on native, surfaced roads would offset potential erosion or sedimentation that may otherwise 

occur from removing the deer seasonal restriction. Therefore, no effects to aquatic species would occur 

from this action.

Fisheries (trout) and Macroinvertebrates: Affected Environment 

Aquatic or Benthic Macroinvertebrates (BMI) were selected as the MIS for riverine and lacustrine habitat 

in the Sierra Nevada. They have been demonstrated to be very useful as indicators of water quality and 

aquatic habitat condition (Resh and Price 1984; Karr et al. 1986; Hughes and Larsen 1987; Resh and 

Rosenberg 1989). They are sensitive to changes in water chemistry, temperature, and physical habitat; 

aquatic factors of particular importance are: flow, sedimentation, and water surface shade.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

416 – Tahoe National Forest

Fisheries (trout) and Macroinvertebrates:

Environmental Consequences 

Direct and Indirect Effects to Fisheries (trout) and Macroinvertebrates

Habitat Factor(s) for the Analysis: Flow; Sedimentation; and Water surface shade

Flow: this habitat factor will be evaluated by assessing changes in the miles of perennial stream flow and 

intermittent stream flow, and changes in acres of lakes and ponds.

Sedimentation: this habitat factor will be evaluated by assessing miles of stream and acres of lake 

potentially affected by sediment discharge as a result of native surfaced route crossings on streams and 

proximity of routes to streams, lakes and ponds. Sedimentation will be measured by route density within 

RCAs and Stream crossing density within RCAs.

Water surface shade: this habitat factor will be evaluated by assessing changes in water surface 

shade as a result of motorize route additions to the NFTS and reopened ML 1 roads that cross streams or 

are adjacent to streams, lakes and ponds. This change will serve to indicate changes in water surface 

shade to perennial and intermittent streams, and lakes and ponds.

Current Condition of the Habitat Factor(s) in the Project Area

Flow: There are currently 1,398 miles of perennial streams, 941 miles of intermittent streams, and 

approximately 11,599 acres of lakes, ponds, and reservoirs on Tahoe NF including on National Forest 

System lands. These miles of perennial and intermittent streams, and acres of lakes, ponds, and reservoirs 

comprise the habitat for aquatic macroinvertebrates across the Forest.

Sedimentation: Native surfaced, motorized stream crossings and motorized routes within close 

proximity to riverine and lacustrine habitats can be a considerable source of sediment delivery to aquatic 

habitats important to macroinvertebrates (See Chapter 3.02, Watershed Resources: Geology, Soil, and 

Hydrology). There are currently 2,462 native surfaced, stream crossings, and 1,081 miles of roads and 

trails within RCAs on the Tahoe NF. There are 3 water bodies on the Tahoe NF that are listed as impaired 

for sediment on the EPAs 303(d) List. These are Truckee River, Humbug Creek, and Squaw Creek. 

Water surface shade: Water surface shade varies tremendously on the Tahoe NF depending on the 

type and amount of vegetation, topographic features, floodplain type, etc. that the watercourse falls 

within.

Cross Country Travel

Under Alternative 1, no action, motorized cross country travel would continue on approximately 149,277 

acres within Riparian Conservation Areas (RCAs), where the potential for adversely affecting aquatic 

macroinvertebrate habitat factors through increases in sedimentation and alteration of water surface 

shade. Under the action alternatives, prohibitions on cross country travel on 149,277 acres within RCA’s 

would likely reduce the potential for sedimentation and alteration of water surface shade, and therefore 

benefit aquatic riverine and lacustrine habitat quality.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 417

Establishment of Motorized “Open Areas”

The establishment of motorized “Open Areas” is analyzed under “Effects Common to All Aquatic 

Species.”

Additions to the NFTS

Number of Native Surfaced, Stream Crossings. The number of native surfaced, stream crossings is 

assessed for the alternatives, and provides a way to compare changes in sediment into riverine and 

lacustrine habitats for aquatic macroinvertebrates (Table 3.03-115). Alternative 1 poses the greatest risk of 

increased sedimentation where 848 stream crossings are affected by the continuance of cross country 

travel on existing unauthorized motorized routes. 

All of the action alternatives would result in significantly reducing the number of native surfaced 

stream crossings and thereby significantly benefiting riverine and lacustrine habitats for aquatic 

macroinvertebrates across the Tahoe NF. Of the action alternatives, Alternative 5 results in the greatest 

number of native surfaced, stream crossings (79 crossings) associated with proposed motorized route 

additions, followed by Alternatives 2, 6, 7, and 4, in descending order. Alternative 3 does not add 

motorized routes to the NFTS, and therefore macroinvertebrate habitat factors of sedimentation or water 

surface shade would not be affected.

Table 3.03-116. Number of Native Surfaced, Stream Crossings Associated with Additions to the NFTS

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Motorized Stream crossings associated with proposed 

additions to the NFTS (negative impact)

0 28 0 14 79 40 15

Stream Crossings that would remain with the continuance of 

cross country travel on existing unauthorized routes 

(negative impact)

848 0 0 0 0 0 0

Crossings prohibited to cross country travel (positive impact) 0 820 848 834 769 808 833

Crossings Closed by previous NEPA decisions, pending 

implementation (positive impact)

54 54 54 54 54 54 54

Miles of Route Additions within RCAs. The miles of proposed motorized route additions to the 

National Forest Transportation System (NFTS) within RCAs were assessed for the alternatives, and 

provide additional information to assess the potential for off-site sediment delivery into riverine and 

lacustrine habitats for aquatic macroinvertebrates (Table 3.03-117). Alternative 1 poses the greatest risk to 

increased sedimentation potential from 327 miles of unauthorized routes within RCAs that would remain 

due to not prohibiting cross country travel. Similar to stream crossing numbers, Alternative 5 would also 

result in the greatest number (31 miles) of motorized routes within RCAs that would be added, followed 

by Alternatives 6, 2, 7, and 4, in descending order. As stated above, Alternative 3 does not add motorized 

routes to the NFTS, and therefore changes to macroinvertebrate habitat factors including sedimentation or 

water surface shade would not occur.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

418 – Tahoe National Forest

Table 3.03-117. Miles of Route Additions within Riparian Conservation Areas (RCAs)

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

RCA miles of motorized route additions to the 

NFTS (negative impact)

327.3 12.3 0 5.6 31.0 18.2 6.8

Existing unauthorized RCA route miles prohibited 

to cross country travel (positive impact) 

0 315.0 327.3 321.7 296.3 309.1 320.5

Miles closed by previous NEPA decisions, 

pending implementation (positive impact)

26.4 26.4 26.4 26.4 26.4 26.4 26.4

*Alternative 1 includes existing native surfaced routes, unauthorized to motorized use, while all the other Alternatives include 

motorized route additions to NFTS.

Changes to the NFTS

Change in Class of Vehicle. The change in class of vehicle may change the impacts to soil and water 

resources due to the potential change from smoothed surfaced route to native (rough) surfaced route (See 

Chapter 3.02, Watershed Resources: Geology, Soil, Hydrology). If the route changes from smoothed 

surfaced to native surfaced, the change in class of vehicle would potentially result in increased sediment 

and erosion risk to riverine and lacustrine habitats. The analysis of the change in class of vehicles 

indicates Alternatives 2, 5, and 6 would result in an increase in the number of high risk crossings 

(Alternatives 2 and 5 – 103 crossings, Alternative 6 – 78 crossings) and RCA route miles (Alternative 2 –

34.3 mi, Alternative 5 – 25.2 mi, Alternative 6 – 13.9 mi) (Table 3.03-118). No change in class of vehicles 

would occur in Alternatives 1 and 3, and small increases in high risk routes (4 crossings, 2 RCA miles) 

would occur in Alternatives 4 and 7.

Table 3.03-118. Change in Class of Vehicle Impacts to Riverine and Lacustrine Habitats

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Number of Native Surfaced Crossings 0 103 0 4 103 78 4

RCA Miles of Native Surfaced Routes 0 34.3 0 2.0 25.2 13.9 2.0

Reopened ML 1 Roads. Only Alternatives 5 and 6 would propose to reopen native surfaced, ML 1 

roads where the potential to capture and deliver sediment to riverine and lacustrine habitats could occur.

Alternative 5 would potentially impact the greatest amount of riverine and lacustrine habitats where 46 

crossings and 14.8 miles within RCAs would be reopened. Alternative 6 would affect a much lesser extent 

of riverine and lacustrine habitats, where 3 crossings and 2.2 RCA miles would be reopened and 

potentially increasing sediment delivery to streams and lake habitats. The remaining alternatives would 

not affect riverine and lacustrine habitats (Table 3.03-119).
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 419

Table 3.03-119. Riverine and Lacustrine Habitat Effects from Reopened ML 1 Road

Alt 1*, 2, 3, 4, 7 Alt 5 Alt 6

Number of Native Surfaced Crossings 0 46 3

RCA Miles of Reopened ML 1 Roads 0 14.8 2.2

*Alternative 1 includes existing native surfaced routes, unauthorized to motorized use, while all the other Alternatives include 

motorized route additions to NFTS.

Summary of Direct and Indirect Effects to Macroinvertebrate Habitat Factors

Tables 3.03-120 and 3.03-121 summarizes the direct and indirect effects of macroinvertebrate habitat 

factors for the alternatives from proposed motorized route additions to the National Forest Transportation 

System and cross country travel, including existing unauthorized motorized routes. None of the action 

alternatives are expected to measurably change the amount of habitat within intermittent, perennial 

streams, lakes, ponds, and reservoirs. Flows within intermittent and perennial streams are expected to 

remain in existing conditions. Habitat quality would be affected from changes to sedimentation and to 

water surface shade. The following actions are assessed for their potential to affect sedimentation, and to 

a lesser degree to water surface shade. Native surface road and motorized route crossings and within close 

proximity to watercourses have the potential to alter riparian habitat and therefore change the amount of 

water surface shade. These factors are measured by assessing the miles of native surface roads and 

motorized routes within the Riparian Conservation Areas (RCAs) and the number of stream crossings 

within RCAs. RCAs are defined as the area within 150 feet on each side of intermittent streams and 300 

feet of perennial streams. Lakes, ponds, and reservoirs are considered perennial and have a 300-foot 

RCA. Water surface shade would be generally be reduced or lost by a very limited amount where shade 

has been removed by the proposed route crossings. Water surface shade alteration will depend upon the 

width of the crossing and the type of vegetation present at the crossing. Within some watercourses, water 

surface shade would either not be altered or only minimally reduced, such as, crossings within forested 

habitats. Crossings through riparian vegetation (herbaceous meadow plants and woody riparian shrubs) 

have resulted in a reduction of some water surface shade. The amount of water surface shade will depend 

on the width of the crossings and the number of crossings.

Table 3.03-120. Summary of Effects from Motorized Route Additions to the NFTS, Reopened ML 1 Roads and 

Changes in Maintenance Levels

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Motorized Stream crossings associated with proposed motorized route additions to the NFTS

Native Surface Crossings 848 28 0 14 79 40 15

RCA Miles 327.3 12.3 0 5.6 31.0 18.2 6.8

Reopened ML 1 Roads

Number of Native Surfaced Crossings 0 0 0 0 46 3 0

RCA Miles 0 0 0 0 14.8 2.2 0

Change in Maintenance Level from smooth surfaced to rough surfaced

Number of Native Surfaced Crossings 0 103 0 4 103 78 4

RCA Miles of Native Surfaced Routes 0 34.3 0 2.0 25.2 13.9 2.0
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

420 – Tahoe National Forest

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Motorized Stream crossings associated with proposed motorized route additions to the NFTS

Native Surface Crossings 848 28 0 14 79 40 15

RCA Miles 327.3 12.3 0 5.6 31.0 18.2 6.8

Reopened ML 1 Roads

Number of Native Surfaced Crossings 0 0 0 0 46 3 0

RCA Miles 0 0 0 0 14.8 2.2 0

Change in Maintenance Level from smooth surfaced to rough surfaced

Total Native Crossings from proposed 

alternatives

848 131 0 18 228 121 19

Total Native Surface RCA Miles 327.3 46.6 0 7.6 71.0 34.3 8.8

*Alternative 1 includes existing native surfaced, stream crossings and unauthorized routes, while all the other Alternatives include 

additions of motorized routes and crossings and reopened ML 1 roads.

Table 3.03-121. Summary of Effects to Aquatic Macroinvertebrate Habitat Factors for the Alternatives

Alternatives Changes in habitat 

quality in miles of Stream 

and Acres of Lakes/

Ponds/ Reservoirs

Changes in Sediment Levels Changes in Water Surface 

Shade

Alt 1* Low Increases the greatest 

(327.3 RCA unauthorized route miles, 

848 unauthorized crossings) 

Decreases 

Alt 2 Low Decreases more than Alt 5

(46.6 RCA route miles, 131 crossings)

Increases compared to Alt 1

Alt 3 Low Decreases the most compared to Alt 1 

(Adds no RCA miles or crossings)

Increases the most 

compared to Alt 1

Alt 4 Low Decreases more than Alt 7

(7.6 RCA miles, 18 crossings)

Increases 2nd most 

compared to Alt 1

Alt 5 Low Decreases the least 

(71.0 RCA miles, 228 crossings)

Increases the least 

compared to Alt 1

Alt 6 Low Decreases more than Alt 2

(34.3 RCA miles, 121 crossings)

Increases compared to Alt 1

Alt 7 Low Decreases more than Alt 6

(8.8 miles, 19 crossings)

Increases compared to Alt 1

*Alternative 1 includes existing native surfaced, stream crossings and unauthorized routes, while all the other Alternatives include 

additions of motorized routes and crossings and reopened ML 1 roads.

Cumulative Effects to Habitat in the Analysis Area

The spatial boundary for analyzing cumulative effects to aquatic macroinvertebrates include all perennial, 

intermittent streams, lakes, ponds, and reservoirs located within the boundary of the Tahoe NF. The 

temporal boundary is approximately 20 years in the past and 20 years into the future.

Past and current cumulative effects to aquatic macroinvertebrate habitat that have affected the habitat 

factors of flow, sedimentation, and surface shade include current and historic grazing along watercourses; 

loss of habitat (shade) and increased sedimentation through catastrophic wildfires; timber and fuels 

management where sedimentation has increased and cover has been reduced or removed; mining and 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 421

dredging, urban development and expansion within a highly checkerboard land ownership pattern; and 

recreational activities including hunting, camping, and general recreation activities including all forms of 

motorized use including 4 wheeled drive vehicles, ATVs, and motorcycles.

The Tahoe NF currently has 31 active livestock grazing allotments including both cattle and sheep. 

Tahoe LRMP standards and guidelines, as amended by the Sierra Nevada Forest Plan Amendment (USFS 

2004), for grazing are generally reducing the amount of grazing impacts on rangelands. 

Appendix H (Reasonably Foreseeable Projects and Cumulative Effects) provides a list and 

description of past, present, and reasonably foreseeable projects on NFS and private lands within the 

Tahoe NF boundary. Some, but not all, of these activities would contribute to impacts to the aquatic 

macroinvertebrates within the Tahoe NF boundary. Since 1990, more than 130,000 acres of vegetation 

management activities have occurred on the Tahoe NF. Some, but not all, have resulted in impacts to 

aquatic macroinvertebrate habitats. Between 2001 and 2007, over 13,000 acres of forest vegetation and 

fuels projects were completed, which primarily thinned, masticated, and/or burned vegetation to reduce 

the potential for catastrophic wildfires. Many recent, current, and future vegetation and fuels reduction 

projects are designed to minimize affects to stream and riparian habitats by following “riparian 

conservation objectives” as prescribed in the Sierra Nevada Forest Plan Amendment. Between 1994 and 

2007, approximately 94,000 acres burned on the Tahoe NF, some of which may have resulted in changes 

in flow, increased sedimentation, and loss in surface cover. 

Generally, the increase in recreational use on the Tahoe NF has the potential to cause an increased 

impact to aquatic macroinvertebrate habitats particularly during the summer months because humans are 

attracted to streams, lakes, ponds, and reservoirs.

Cumulative Effects Conclusion

For the action alternatives, generally, changes in flow and water surface shade would be too small to be 

measured. When considering all the cumulative effects of past, present, and reasonably foreseeable future 

impacts from grazing, vegetation/fuels projects, wildfires, mining, and recreation, Alternative 1 poses the 

greatest risk to the riverine and lacustrine habitats on the Tahoe NF, where cross country travel would 

continue on 149,277 acres within Riparian Conservation Areas with the highest potential to reduce habitat 

quality by increasing sediment delivery and alter water surface shade to aquatic macroinvertebrate 

habitats. Sedimentation of macroinvertebrate habitats would be greatest under Alternative 1, where 848 

stream crossings and 327 RCA miles would continue to have use on unauthorized routes since cross 

country would not prohibited. 

For the action alternatives, Alternative 5 would result in the greatest cumulative number of native 

surfaced, stream crossings and RCA miles, followed by Alternatives 2, 6, 7, 4, and 3, in descending order 

from the addition of motorized routes, changes in maintenance level, and reopened ML 1 roads. 

Alternative 3 does not add any stream crossings, reopen any ML 1 roads, or change maintenance levels, 

and therefore Alternative 3 would not add any cumulative impacts to aquatic macroinvertebrate habitats.

Wet weather seasonal restrictions under Alternatives 4, 5, and 6 on all native surfaced routes would 

benefit macroinvertebrate habitat through the reduction of erosion and sedimentation that could result 
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422 – Tahoe National Forest

from wet season wheeled motorized use on routes, especially wheeled motorized routes that are within 

close proximity to macroinvertebrate habitats.

Summary of Direct, Indirect, and Cumulative Effects of Proposed Actions

Tables 3.03-122 and 3.03-123 summarizes the direct, indirect, and cumulative effects of all native 

surfaced motorized route crossings and miles within RCAs, including existing routes, motorized route 

additions to the NFTS, changes in class of vehicles, and prohibition of cross country travel. See Chapter 

3.02 (Watershed Resources: Geology, Soil, Hydrology) for more detailed information and assumptions.

Table 3.03-122. Net Direct, Indirect, and Cumulative Effects to Number of Native Surfaced, Stream Crossings 

from Motorized Route Crossing Additions, Cross Country Travel, and Change in Maintenance Level, and 

Reopened ML 1 Roads

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Crossings Prohibited to Cross Country Travel 

(positive)

0 820 848 834 769 808 833

Existing NFTS Motorized Crossings (negative) 2,462 2,462 2,462 2,462 2,462 2,462 2,462

Motorized Crossing Additions (negative) 848 28 0 14 79 40 15

Change in maintenance level (smooth to rough 

surfaced) (negative)

0 103 0 4 103 78 4

Reopened ML 1 Roads (negative) 0 0 0 0 46 3 0

Crossings Closed by Previous NEPA decisions, 

pending implementation (positive)

54 54 54 54 54 54 54

Net Direct, Indirect, and Cumulative Effect = 

Total Native Surface Motorized Crossings

3,310 2,593 2,462 2,480 2,644 2,580 2,481

*Alternative 1 includes existing native surfaced, stream crossings unauthorized to motorized use, while all the other Alternatives 

include motorized crossing additions.

Table 3.03-123. Net Direct, Indirect, and Cumulative Effects to Native Surfaced, RCA Miles from Motorized 

Route Additions to the NFTS, Prohibition of Cross Country Travel, and Change in Class of Vehicles 

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Existing RCA Motorized Miles (negative) 472.7 472.7 472.7 472.7 472.7 472.7 472.7

Miles of Native Surfaced Motorized RCA Additions 

(negative)

327.3 12.3 0 5.6 31.0 18.2 6.8

Miles of Native Surfaced Routes Prohibited to 

Country Travel (positive)

0 315.0 327.3 321.7 296.3 309.1 320.5

Change in Maintenance Level from smooth surfaced 

to rough surfaced (negative)

0 34.3 0 2.0 25.2 13.9 2.0

RCA Miles of Reopened ML 1 Roads (negative) 0 0 0 0 14.8 2.2 0

Net Direct, Indirect, and Cumulative Effect =

Total Motorized RCA Miles

800.0 519.3 472.7 480.3 543.7 507.0 481.5

*Alternative 1 includes miles of existing native surfaced, unauthorized routes, while all the other alternatives include miles of 

motorized route additions.

Summary of Aquatic Macroinvertebrate Status and Trend at the Bioregional Scale. The Tahoe 

NF LRMP (as amended by the SNF MIS Amendment) requires bioregional-scale Index of Biological 

Integrity and Habitat monitoring for aquatic macroinvertebrates; hence, the lacustrine and riverine effects 
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Tahoe National Forest – 423

analysis for the Tahoe NF Motorized Travel Management Project must be informed by these monitoring 

data. The sections below summarize the Biological Integrity and Habitat status and trend data for aquatic 

macroinvertebrates. This information is drawn from the detailed information on habitat and population 

trends in the Sierra Nevada Forests Bioregional MIS Report (USDA Forest Service 2008), which is 

hereby incorporated by reference.

Habitat and Index of Biological Integrity Status and Trend. Aquatic habitat has been assessed 

using Stream Condition Inventory (SCI) data collected since 1994 (Frasier et al. 2005) and habitat status 

information from the Sierra Nevada Ecosystem Project (SNEP) (Moyle and Randall 1996). Index of 

Biological Integrity is assessed using the River Invertebrate Prediction and Classification System 

(RIVPACS) and macroinvertebrate data collected since 2000 (see USDA Forest Service 2008). These data 

indicate that the status and trend in the RIVPACS scores is stable.

Relationship of Project-Level Habitat Impacts to Bioregional-Scale Aquatic Macroinvertebrates 

Habitat Trend. The Tahoe NF Motorized Travel Management Project would affect the greatest amount of 

macroinvertebrate habitat under Alternative 1, through increased sedimentation and decreased surface 

shade, where approximately 327 miles of existing unauthorized motorized routes would continue to occur 

under the continuance of cross country travel within RCAs. These existing unauthorized routes would 

effectively result in the continued use of 848 native surfaced, stream crossings that could adversely affect 

the quality of macroinvertebrate habitats through increased sediment delivery and decreased surface water 

shade.

Of the action alternatives, Alternative 5 would result in the greatest amount impact to 

macroinvertebrate habitats, though the potential increase in sedimentation and decrease in surface water 

shade from motorized stream crossings and RCA route miles (71 RCA miles, 228 crossings), followed by 

Alternatives 2, 6, 7, 4, and 3, in descending order from the motorized additions, reopened ML 1 roads, 

and changes to maintenance level. Alternative 3 does not add any stream crossings or motorized routes 

within RCAs because no motorized route additions to the NFTS are proposed under this alternative. 

The action alternatives would not alter the existing trend in macroinvertebrate habitat, nor would it 

lead to a change in the distribution of macroinvertebrates across the Sierra Nevada bioregion. This is 

based on the relatively low amount of lacustrine and riverine habitat affected, the prohibition of cross 

country travel within 149,277 RCA acres, including on between 296 and 327 motorized RCA miles, and 

on between 769 and 848 stream crossings.

Cumulative Effects of Past, Present, and Future Actions

The cumulative effects boundary includes all Forest Service System lands and private lands within the 

boundary of the Tahoe NF. This includes all major 7th field watersheds, which sufficiently analyzes 

cumulative effects to all perennial, intermittent, and ephemeral streams within the Forest boundary. Any 

larger boundary would be cumbersome and potentially dilute any cumulative effects.

Past, present, and future cumulative effects to aquatic organisms on both National Forest System 

lands and private lands includes a host of activities including timber management and the large network 

of roads associated with it; fuels projects including prescribed burning; recreation activities including 
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424 – Tahoe National Forest

camping, fishing, hiking, off-highway travel, and sight-seeing; historic and present day mining activities 

have had significant impacts to fisheries; water diversions including dams and hydroelectric projects; 

livestock grazing both historic and current have greatly impacted the fisheries resource; and last, but not 

least urbanization on the Tahoe NF represented by the checkerboard ownership pattern has and continues 

to affect landscape connectivity of streams on the Tahoe NF.

Alternative 1 would add the greatest cumulative impacts to aquatic resources on the Tahoe NF from 

highest route densities within Riparian Conservation Areas and the highest proportion of stream 

crossings. All action alternatives would decrease the potential risk to fisheries and macroinvertebrate 

populations by decreasing the amount of motorized used on native surface routes. Alternative 5 would 

decrease the potential effects the least. Alternatives 3 and 4 would decrease the risks the most. Roads on 

private lands add considerable cumulative effects to the aquatic resources. Unmanaged cross country 

travel would continue to occur and increase at an unknown rate under Alternative 1 where impacts to 

aquatic resources are uncertain. Under all the action alternatives, cross-country travel would be 

prohibited. Over time, benefits to aquatic would be realized once these routes are revegetated and 

rehabilitated.

Lahontan Cutthroat Trout: Affected Environment

Introduction: The Lahontan cutthroat trout (LCT) was listed by the U.S. Fish and Wildlife Service 

(USFWS) as an endangered species in 1970 (Federal Register Vol. 35, p. 13520). The listing was 

reclassified to threatened status in 1975 to facilitate recovery and management efforts and authorize 

regulated angling (Federal Register Vol. 40, p. 29864). Currently, no Critical Habitat has been designated 

for the LCT (USFWS 1995).

Historically, LCT was thought to occupy approximately 360 miles of the Truckee River, 300 miles of 

the Carson River, and 360 miles of the Walker River in northern California and western Nevada (Somer 

1998). Lahontan cutthroat trout historically occurred in Tahoe, Cascade, Fallen Leaf, Upper Twin, Lower 

Twin, Pyramid, Winnemucca, Summit, Donner, Walker, and Independence Lakes (Moyle 1976, Gerstung 

1988). Currently, LCT recovery populations on the Tahoe NF occupy one lake and five streams. The 

Tahoe National Forest has designated the lake (Independence Lake) and the stream flowing into it (Upper 

Independence Creek) as a Critical Aquatic Refuge (CAR).

The Truckee River Basin Recovery Implementation Team (TRRIT) has established recovery 

objectives for various reaches of the Truckee River and its tributaries. Important recovery areas that the 

TRRIT has initially identified as having immediate potential include: Independence Creek, upstream of 

Independence Lake; Pole Creek; Hunter Creek; Donner Creek; Perazzo Creek; Prosser Creek; and the 

Truckee River from its confluence with Donner Creek to the State line; Upper Truckee River; Truckee 

River from Tahoe Dam to Donner Creek; and, Independence Creek downstream from Independence Lake 

to the Little Truckee River. The TRRIT has identified Macklin and East Fork Creeks and an unnamed 

tributary to the East Fork Creek in the Yuba River system as necessary for recovery of LCT because they 

contain remnants of indigenous Truckee River Basin strains.
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Tahoe National Forest – 425

The LCT currently occupies eleven 7th field watersheds on the Tahoe NF: Middle Truckee River-Pole 

Creek, Independence Lake, Middle Yuba River-Milton Reservoir, and East Fork. In addition, Lahontan 

cutthroat trout have been re-introduced into the Truckee River for recreational sport fishing. In 2006, 

Lahontan cutthroat trout were released into Sagehen Creek as part of research project. 

Habitat attributes considered important for Lahontan cutthroat trout include:

• Cool water temperatures

• Stable stream banks

• Sufficient coarse woody debris 

• Spawning gravel with low percentages of sand/silt 

• Deep pools

• 1:1 pool to riffle ratio

Route Associated Risk Factors: Potential road and trail associated risk factors to the LCT include 

the immediate loss of individual fish and loss of specific habitat features such as undercut banks used for 

cover, increases in sedimentation leading to changes in spawning bed capacity, and the loss of riparian 

vegetation necessary to maintain adequate temperature regime (SNFPA 2001).

Lahontan Cutthroat Trout: Environmental Consequences

In 2006, the U.S. Forest Service entered into programmatic consultation with the U.S. Fish and Wildlife 

Service for route designation (travel management) for motor vehicles in 14 National Forests in California. 

The BE for the Tahoe NF Motorized Travel Management Project and this programmatic consultation is 

incorporated by reference. Project design criteria were developed jointly, which includes measures to 

avoid impacts to federally listed species, including the Lahontan cutthroat trout. The U.S. Fish and 

Wildlife Service has agreed that, by using the Project Design Criteria for each of the Threatened and 

Endangered species and Critical Habitat, route designation will meet “No Effect” or “May Affect, Not 

Likely to Adversely Affect” determinations and that they would concur with these determinations on a 

programmatic basis. Forest consultation can tier to the programmatic consultation with no further 

consultation. However, the FSW states that these criteria are for the Inyo, Sierra, and Stanislaus Nationals 

Forests only. The Tahoe and Humboldt-Toiyabe National Forests must have local project consultation for 

Lahontan cutthroat trout, since the Reno Office has responsibility for Section 7 Consultation on this 

species for these National Forests. Informal consultation for the LCT with the FWS Reno Office and the 

Sacramento Office occurred on August 22, 2007 regarding the Tahoe NF Motorized Travel Management 

Project. The FWS agreed that the Project Design Criteria which were developed through the 

programmatic consultation process should also be used to achieve a “No Effect” or “May Affect, Not 

Likely to Adversely Affect” determination for the LCT for the Tahoe NF. As such, the following Project 

Design Standards for LCT are described and how the Tahoe NF Motorized Travel Management Project is

consistent with each Project Design Criteria. More specific information on the effects of the alternatives is 

described in the sections that follow.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

426 – Tahoe National Forest

Consistency with Project Design Criteria to Achieve “No Effect” and “Not Likely 

to Adversely Affect” Determinations

Routes and areas do not cross any stream within the occupied range of Lahontan cutthroat trout.

• There are no proposed route additions to the NFTS that cross any stream occupied by Lahontan 

cutthroat trout.

• The change in class of vehicles on the Pole Creek Road (Road #5708) that would result in changed 

maintenance levels proposed in Alternatives 2, 5, and 6 are outside the Pole Creek RCA.

Therefore, occupied habitat in Pole Creek would not be affected.

Routes and areas are not located on active landslides and do not re-route surface water onto active 

landslides within watersheds that provide habitat for Lahontan cutthroat trout. 

• There are no proposed route additions that cross any stream occupied by Lahontan cutthroat trout, 

and therefore, no proposed route additions are located on active landslides within watersheds that 

provide habitat for LCT.

Within watersheds that provide habitat for Lahontan cutthroat trout, routes or areas do not have 

the potential to capture surface run-off and then deliver sediment into a stream. 

• The Travel Management action alternatives do not propose route or area additions that have the 

potential to capture surface run-off and then deliver sediment into any occupied LCT streams. 

• A 1⁄2 mile segment of the existing Pole Creek Road (Road #5708) parallels occupied LCT habitat 

within Pole Creek. This 1⁄2 mile road segment is within the Pole Creek RCA and would be 

maintained at the current Maintenance Level 3 standard, and therefore would not increase 

sediment delivery to occupied Lahontan cutthroat trout habitat at Pole Creek. 

• Established Motorized “Open Areas” are located outside of Riparian Conservation Areas that are 

within watersheds that provide habitat for Lahontan cutthroat trout.

• The action alternatives do not propose motorized area additions or reopen ML 1 roads that are 

within watersheds or Riparian Conservation Areas that provide habitat for Lahontan cutthroat 

trout.

Within watersheds that provide habitat for Lahontan cutthroat trout, “motorized routes” avoid 

Riparian Conservation Areas.

• The action alternatives do not propose motorized route additions, reopening ML 1 roads, or would 

result in changed maintenance standards within watersheds or Riparian Conservation Areas that 

provide habitat for Lahontan cutthroat trout.

Indicators used to Measure Effects

Cross Country Travel: The prohibition of cross country travel is analyzed for the alternatives to estimate 

the potential benefits and reduction in effects to occupied LCT streams from motorized cross country 

travel.

Additions to the NFTS (LCT 7th field watersheds): Measures or indicators of changes in 

sedimentation and water surface shade are assessed by analyzing the number of stream crossings 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 427

additions associated with motorized route additions to the National Forest Transportation System, and the 

miles motorized route additions to the NFTS within Riparian Conservation Areas (RCAs) for occupied 

LCT streams.

Site-specific Physical Impacts and Disturbance to occupied Lahontan cutthroat trout streams: 

Proposed motorized route additions to the NFTS were evaluated to determine site-specific impacts to 

occupied LCT streams for each of the alternatives. Native surfaced routes that cross or intersect LCT 

streams and lakes have the greatest potential to disturb LCT, kill and crush LCT egg masses (redds) and to 

alter stream banks and deliver sediment which can degrade LCT habitat condition. In addition, motorized 

route additions to the NFTS within the Riparian Conservation Areas (RCAs) of occupied LCT 

streams/lakes were also evaluated by the alternatives.

Wet Weather Seasonal Closures: Proposed wet weather seasonal restrictions on native surfaced 

route are analyzed under the section “Effects Common to All Aquatic Species.”

Change in Class of Vehicles: Changing the class of vehicle on a particular route potentially changes 

the impacts to soil and water resource due to changes in the road surface (i.e. from smooth surfaced to 

rough surfaced) (see Chapter 3.02, Watershed Resources: Geology, Soil, and Hydrology). If the route 

changes from smoothed surfaced to native surfaced, the change in class of vehicle may result in increased 

sediment and erosion risk to occupied LCT streams. The change in class of vehicle and associated 

maintenance downgrades is evaluated for their potential to affect occupied LCT streams. 

Reopened ML 1 Roads: The alternatives are analyzed for their potential to affect LCT habitat by 

reopening ML 1 Roads.

Route Density within Riparian Conservation Areas (RCAs): Route densities of native surfaced 

routes within RCAs were evaluated to compare the overall effects of all motorized routes (including 

existing routes and routes unauthorized to motorized public use) for the alternatives within each 7th field 

watershed occupied by LCT. According to Chapter 3.02 (Watershed Resources: Geology, Soil, 

Hydrology), Level 2 roads and below have the greatest potential for off-site sediment delivery into 

streams and lakes. Therefore, this effects analysis includes route density of all native surfaced motorized 

routes (including existing NFTS and unauthorized routes). Route density provides a relative index to 

measure the potential indirect effects to occupied habitat of LCT from increased sedimentation from 

routes. Thresholds for route density have not been established, however, route density provides a relative 

way to compare the effects of the alternatives.

Stream Crossing Density within RCAs: The 7th field watersheds occupied by LCT were evaluated 

for the crossing density of native surfaced motorized routes within RCAs to compare direct and indirect 

effects of motorized routes for the alternatives. Route crossing density provides a way to measure the 

potential direct and indirect effects to LCT and habitat. Direct effects include potential LCT mortality as a 

result of use of motorized crossings of occupied LCT streams. Indirect effects include changes to channel 

and streambank characteristics and changes in vegetation structure. Thresholds for motorized crossing 

route density have not been established, however, route crossing density provides a relative way to 

compare the effects of the alternatives.
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428 – Tahoe National Forest

Direct and Indirect Effects

Cross Country Travel 

Under Alternative 1, no action, motorized cross country travel would continue on approximately 15,437

acres within Riparian Conservation Areas (RCAs) of occupied LCT streams, where the potential for 

adversely affecting occupied LCT habitat could occur by increasing sedimentation and altering water 

surface shade. The prohibition of cross country travel results in reducing motorized use on approximately 

50 RCA miles and on 48 crossings for all the action alternatives, and continues under Alternative 1. Under 

the action alternatives, prohibitions on cross country travel on 15,437 acres within RCA’s of occupied

LCT streams (50 RCA miles and 48 stream crossings) would likely reduce the potential for sedimentation 

and alteration of water surface shade, and therefore benefit LCT habitat quality.

NFTS Additions and “Open Areas” – Stream Crossings and Miles of Motorized Route Additions

Number of Native Surfaced, Stream Crossing Additions within LCT 7th Field Watersheds. At the 7th

field watershed scale (HUC7), the number of native surfaced, crossing additions are assessed for the 

alternatives, and provides a way to compare changes in sediment into occupied LCT habitats at the HUC 

7 watershed scale where LCT streams are located. Alternative 1 poses the greatest risk of increased 

sedimentation where 48 stream crossings are affected by the continuance of cross country travel on 

unauthorized motorized routes. All the action alternatives would result in reducing the number of high 

risk (native surface) crossings within LCT HUC7 watersheds within the Truckee River or within Macklin 

Creek.

Alternative 6 would result in adding a total of 4 stream crossings within two HUC7 watersheds 

(Middle Truckee River-Lower Prosser Creek and Middle Yuba River-Milton Reservoir). None of the 

crossings would deliver sediment to the Occupied LCT streams (Table 3.03-124).

Alternatives 2, 4, 5, and 7 would result in adding 3 stream crossings within the Stampede Reservoir 

HUC7 watershed. These 3 crossings are located in the northeastern portion of the HUC7 and would not 

contribute sediment into Lower Sagehen Creek which drains into Stampede Reservoir at the southern and 

western edge of the watershed. Therefore, no effects to LCT within Lower Sagehen Creek would occur 

from these added crossings.

Alternative 3 does not add motorized crossings to the NFTS, and therefore sedimentation or water 

surface shade would not be affected within any LCT HUC7 watershed, or to any occupied LCT streams.

Table 3.03-124. Lahontan cutthroat trout 7th Field Watersheds - Number of Native Surfaced, Stream 

Crossings Associated with Motorized Route Additions to the NFTS

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Motorized Stream crossings associated with 

proposed motorized route additions to the NFTS 

(negative impact)

0 3 0 3 3 4 3

Number existing motorized unauthorized routes 

not prohibited to cross country travel (negative 

impact)

48 0 0 0 0 0 0
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 429

Miles of Proposed Route Additions within RCAs of LCT 7th Field Watersheds. The miles of 

proposed motorized route additions to the NFTS within RCAs were assessed for the alternatives, and 

provide additional information to assess the potential for off-site sediment delivery into streams within 

LCT HUC 7 watersheds (Table 3.03-125). Alternative 1 poses the greatest risk to increased sedimentation 

potential from 28.2 RCA miles of unauthorized routes that would remain due to the continuance of cross 

country travel. 

All the action alternatives would reduce the number of RCA miles within LCT HUC7 watersheds. 

Alternatives 2, 4, 5, 6, and 7 propose to add between 0.9 – 1.6 miles within RCAs of LCT HUC7 

watersheds. As stated above, none of the added RCA miles would directly affect RCAs within 

occupied LCT streams. Alternative 3 does not add motorized routes to the NFTS, and therefore changes 

to sedimentation or water surface shade would not occur within any LCT HUC7 watershed.

Table 3.03-125. Miles of Proposed Route Additions within LCT HUC7 Riparian Conservation Areas (RCAs) 

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

RCA Miles of motorized route additions (negative impact) 0 1.6 0 1.6 1.6 0.9 1.6

RCA Miles of existing unauthorized routes not prohibited 

to cross country travel (negative impact)

28.2 0 0 0 0 0 0

Site-specific Physical Impacts and Disturbance to occupied Lahontan cutthroat trout streams

As mentioned above, the LCT occupies eleven 7th field watersheds (HUC7) on the Tahoe NF, as follows:

• Middle Truckee River-Lower Prosser Creek

• Middle Truckee River-Cabin Creek

• Middle Truckee River-Pole Creek

• Middle Truckee River-Silver Creek

• Upper Middle Truckee River

• Independence Lake

• Middle Yuba River-Milton Reservoir

• East Fork

• Upper Sagehen Creek

• Lower Sagehen Creek

• Stampede Reservoir

Alternative 1 poses the greatest risk to LCT where existing unauthorized routes have the potential to 

adversely affect occupied LCT habitat. All the action alternatives do not directly or indirectly affect 

occupied LCT streams, since they do not propose motorized route additions that cross or have the 

potential to delivery sediment to occupied LCT streams. A brief summary of potential direct and indirect 

effects are described for each 7th field watershed that is occupied by LCT.

Middle Truckee River-Lower Prosser Creek, Middle Truckee River-Cabin Creek, Middle 

Truckee River-Silver Creek, and Upper Middle Truckee River: Recreational LCT occupy these four 
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430 – Tahoe National Forest

watersheds within the Truckee River. The description of potential impacts of motorized route additions 

within these watersheds is described below.

Middle Truckee River-Lower Prosser Creek: Two proposed routes fall within the Middle Truckee 

R.-Lower Prosser Creek watershed (TKN-M1, TKN-PP). Both routes are located near Prosser Creek 

Reservoir, and are located over 1 mile away from the mainstem of the Truckee River. Sediment from 

these motorized route additions would not deliver sediment to the Truckee River, and therefore would not 

affect recreational LCT populations.

Middle Truckee River-Cabin Creek: Proposed route addition TKS-M9 falls within the Middle 

Truckee River-Cabin Creek watershed, but this motorcycle route is parallel to the Truckee River, and is 

over 1⁄2 mile east of the Truckee River up on the Sawtooth Ridge area. This single track route would not 

contribute sediment to the mainstem of the Truckee River, and would therefore not affect recreational 

LCT fisheries.

Middle Truckee River-Silver Creek: Approximately 1 1⁄2 mile of the Truckee River flows through 

the middle of this watershed. No proposed route additions occur within the Middle Truckee R.-Silver 

Creek watershed, and therefore no impacts to the LCT fisheries in the Truckee River would occur.

Upper Middle Truckee River: No proposed route additions occur within the Upper Middle Truckee 

River watershed, and therefore no impacts to the LCT fisheries in the Truckee River would occur.

Middle Truckee River-Pole Creek. Pole Creek is currently occupied by LCT and falls within the 

Middle Truckee River-Pole Creek watershed. In addition, recreational LCT occupies the mainstem of the 

Truckee River which bisects the eastern portion of the Pole Creek watershed. No route additions are 

proposed within this watershed under any of the action alternatives. Two existing routes unauthorized to 

motorized public travel would remain under cross country travel in Alternative 1. However, these routes 

do not have the potential to deliver sediment to Pole Creek or to the Truckee River where LCT are 

located.

Independence Lake 7th field watershed. LCT within Independence Lake and upper Independence 

Creek has a high risk of being directly and indirectly affected by Alternative 1 and 5 where approximately 

3 miles of routes unauthorized to motorized public use borders the north side of Independence Lake. The 

remaining action alternatives do not propose motorized route additions within the Independence Lake 

watershed. Existing routes unauthorized to motorized public use bordering the south side of Independence 

Lake on private land would also increase the risk of to LCT from factors associated with motorized use 

from potential sediment delivery into Independence Lake.

Middle Yuba River-Milton Reservoir 7th field watershed. In the Middle Yuba River-Milton

Reservoir watershed, LCT occupies Macklin Creek. Under Alternative 1, one unauthorized route (~1⁄4

mile) within the watershed does not cross, but parallels the headwaters of Macklin Creek, potentially 

delivering sediment into the stream. None of the action alternatives would directly affect LCT within 

Macklin Creek, since they do not propose routes additions within the Middle Yuba River-Milton 

Reservoir.

East Fork Creek 7th field watershed. Within the East Fork Creek watershed, LCT occupies East 

Fork Creek. There would be no direct or indirect effects to LCT within East Fork Creek, since no route 
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Tahoe National Forest – 431

additions are proposed under any of the action alternatives. Under Alternative 1, an existing route 

unauthorized to motorized public use is located outside the Riparian Conservation Area that parallels the 

north side of East Fork Creek connecting two smooth surfaced roads. Sediment delivery into East Fork 

Creek from this route is unlikely.

Upper Sagehen Creek, Lower Sagehen Creek, and Stampede Reservoir watersheds: Three small 

short route segments that provide access to dispersed recreation occurs within the Lower Sagehen Creek 

watershed. These three route segments are stabilized and would not delivery sediment to Sagehen Creek.

No other routes are proposed for addition within these three watersheds, therefore no effects to LCT 

would occur.

Establishment of Motorized “Open Areas”

The establishment of motorized “Open Areas” would not affect any occupied LCT streams, since none of 

the proposed motorized “Open Areas” would deliver sediment or are located within the RCA of any 

occupied LCT streams, including the Greenhorn area and the reservoir areas at Stampede, Boca, and 

Prosser. One HUC7 watershed, Stampede Reservoir, contains lower Sagehen Creek which is downstream 

of where LCT individuals were released during a research project at the Sagehen Experimental Research 

Forest. The proposed established “Open Areas” at Stampede Reservoir are not connected to and would 

not affect lower Sagehen Creek, and therefore would not affect any LCT that may be in lower Sagehen 

Creek.

Changes to the NFTS

Change in Class of Vehicles. For each of the alternatives, Table 3.03-126 displays the effects of proposed 

change in class of vehicles and the associated maintenance changes that have the potential to increase the 

risk of delivering sediment to occupied LCT streams. Alternatives 2, 5, and 6 would maintain the changes 

to road maintenance standards resulting in changes from smooth surfaced roads to rough surfaced roads 

that are likely to occur. 

Under Alternatives 2, 5, and 6, this change in road surface type has a higher potential to result in 

increased sedimentation within the East Fork Creek HUC 7 watersheds with an occupied LCT stream. 

These are the East Fork Creek HUC7 watershed. The East Fork Creek watershed is affected by the change 

in road maintenance standard on one motorized intermittent stream crossing on East Fork Creek, and 

would result in the change from smooth surfaced to native surfaced motorized crossing. The crossing is 

associated with the Pinoli Ridge Road, located approximately 2/3 mile south of the occupied LCT stream 

(un-named tributary to East Fork Creek). The potential for delivering sediment to the occupied LCT 

stream within the un-named to tributary to East Fork Creek is not expected due to streamflow direction. 

For Alternatives 2, 5, and 6, the change in class of vehicles would not result in changed maintenance 

standards on approximately 0.5 RCA miles on the Pole Creek Road (Road 5708) within a watershed with 

an occupied LCT stream (Pole Creek). Project design standards are required to maintain the Pole Creek 

Road at a higher maintenance standard (ML 3) within approximately 0.5 miles adjacent to Pole Creek so 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

432 – Tahoe National Forest

that sediment delivery to Pole Creek would be minimized, therefore, current maintenance standards at 

Pole Creek would not contribute to accelerated erosion or sedimentation.

Table 3.03-126. Effects to LCT 7th Field Watersheds from Change in Class of Vehicles 

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Number of Native Surfaced crossings resulting from 

changes in maintenance from smooth surfaced to native 

surfaced (Pinoli Ridge)

0 1 0 0 1 1 0

Reopened ML 1 Roads: No ML 1 roads are proposed for reopening within any LCT HUC 7 

watersheds under all the alternatives, and therefore LCT would not be affected.

Cumulative Effects

Cumulative Effects Boundary in Time and Space

For this analysis, the geographic boundary used to analyze cumulative effects to LCT is the Truckee River 

and its tributaries. This scale is an appropriate scale to analyze cumulative effects because the Truckee 

River watershed including all its tributaries is the historic range of the Lahontan cutthroat trout within the 

Tahoe NF. Any larger scale may dilute the actual effects of motorized routes and other activities that may 

potential affect occupied LCT streams. Past cumulative effects currently affecting the distribution and 

abundance of LCT considered here include 50 to 100 years out. Future cumulative impacts timeframe for 

reasonably foreseeable actions is approximately 20 years out. 

Cumulative Effects of Motorized Routes

Route Density within Riparian Conservation Areas (RCAs). Chapter 3.02 (Watershed Resources: 

Geology, Soil, Hydrology), analyzed Riparian Conservation Area (RCA) route density for each 7th field 

watershed on the Tahoe NF, and categorized motorized RCA route density (native surfaced) by four route 

density categories. The route density categories were highest (8.9 - 27.3 miles/square mile), moderately 

high (6.3 - 8.8miles/square mile), moderately low (4.3 - 6.2 miles/square mile, and lowest (0.2 - 4.2 

miles/square mile).

Figure 3.03-9 shows the number of HUC7 watersheds occupied by LCT by RCA motorized route 

density by density category. Alternative 1 poses the greatest risk to LCT where 6 LCT HUC7 watersheds 

falls within the highest route density category, 3 in the moderately high, 1 in the moderately low, and 1 in 

the lowest. All the action alternatives would result in reducing route densities within RCAs. Alternatives 2 

and 5 are similar in RCA route densities where 4 HUC7 watersheds are within route density categories of 

highest, 5 within moderately high, 1 within moderately low, and 1 within lowest. Alternative 6 would 

further reduce RCA route density where 4 watersheds fall in the highest and moderately high density 

categories, 1 in the moderately low, and 2 in the lowest. Alternatives 3, 4, and 7 have the least potential 

for effects from cumulative motorized routes within HUC7 watersheds with occupied LCT streams where 

3 watersheds falls within the moderately highest, 4 in the moderately high, 1 in the moderately low, and 3 

in the lowest RCA route density category.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 433

Native Surface, Motorized RCA Route Density 

 HUC7s with Suitable Lahontan Cuthroat Trout Habitat

0%

20%

40%

60%

80%

100%

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Alterrnatives

Percent of Watersheds with Suitable LCT Habitat

highest (8.9 - 27.3)

moderately high (6.3 - 8.8)

moderately low (4.3 - 6.2)

low est (0.2 - 4.2)

Figure 3.03-9. Number of HUC7 Watersheds with Occupied LCT streams by Route Density Categories of 

Lowest, Lower, Higher, and Highest

Stream Crossing Density within RCAs

RCA stream crossing density categories (native surfaced routes) were determined for each 7th field 

watershed with occupied LCT streams on the Tahoe NF by four route density categories. The route 

density categories were highest (5.1-19.7 crossings/sq. mile), moderately high (3.1-5.0) crossings/sq. 

mile), moderately low (1.8-3.0 crossings/sq. mi.), and lowest (0-1.7 crossing/sq. mi.). Figure 3.03-10

displays motorized crossing density within HUC7 watersheds with occupied LCT habitat for each of the 

alternatives. 

Alternative 1 poses the greatest risk to LCT streams from potential sediment delivery, since 6 of 11 

HUC7 watersheds occupied by LCT would fall within the highest, 4 within the moderately high, and 1 

within moderately low categories for route crossing densities. 

Alternatives 2 and 5 pose the next greatest risk to LCT from sedimentation from stream crossings 

where the 4 of 11 HUC7s falls within highest, 4 within moderately high, 2 within moderately low (2), and 

none in the lowest crossing density category. Alternative 6 would result in stream crossing densities where 

4 watersheds would be in the highest, 5 in moderately high, none in moderately low, and 2 in the lowest 

crossing density categories. Alternative 3 followed by Alternatives 4 and 7 would result in the least risk to 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

434 – Tahoe National Forest

Native Surface, Motorized Stream Crossing Density -

HUC7s with Suitable Lahontan Cutthroat Trout Habitat

0%

20%

40%

60%

80%

100%

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Alternatives

Percent of Watersheds with Suitable LCT Habitat

highest (5.1-19.7)

moderately high (3.1-5.0)

moderately low (1.8-3.0)

low est (0-1.7)

LCT watersheds where the least amount of sediment delivery and stream habitat alteration would likely 

occur within LCT watersheds compared to all the other alternatives.

Figure 3.03-10. Number of HUC7 Watersheds with occupied LCT streams by Motorized Crossing Density 

Categories

Summary of Direct, Indirect, and Cumulative Effects of Proposed Actions

Tables 3.03-127 and 3.03-128 summarize the direct, indirect, and cumulative effects to native surfaced, 

motorized route crossing within LCT HUC 7 watersheds, from existing motorized routes, motorized route 

additions, and routes unauthorized to motorized public travel from the proposed actions, including wet 

weather seasonal restrictions, changes in class of vehicles, prohibition of cross country travel. See 

Chapter 3.02 (Watershed Resources: Geology, Soil, Hydrology) for more detailed information and 

assumptions.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 435

Table 3.03-127. LCT 7th Field Watersheds – Summary of Direct, Indirect, and Cumulative Effect of Proposed Actions as Measured by Native Surfaced, 

Motorized Stream Crossings

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

RCA Acres Prohibited 0 15,437 15,437 15,437 15,437 15,437 15,437

Unauthorized Motorized Stream 

Crossings Prohibited to cross 

country travel

1 46 49 46 46 45 46

Motorized Stream Crossings

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Existing NFTS Native Surfaced, 

Stream Crossings

45 45 45 45 45 45 45

Native Surfaced, Motorized 

Route Crossing Additions*

0 3 0 3 3 4 3

Unauthorized Crossings that 

would continue with cross 

country travel

48 0 0 0 0 0 0

Reopened ML 1 Road Crossings 0 0 0 0 0 0 0

Change in Class of Vehicles 

resulting in changed 

maintenance standards resulting 

in smooth surfaced to native 

surfaced within occupied RCA 

stream

0 1 0 0 1 1 0

Net NFTS Native Surfaced, 

Stream Crossings

93 55 45 48 55 55 48

Wet Weather Seasonal 

Restrictions on all Native 

Surfaced Roads and Routes

None None None Beneficial - Wet 

Weather 

Restrictions would 

be implemented 

on 13 crossings

Beneficial - Wet

Weather 

Restrictions would 

be implemented 

on 15 crossings

Beneficial - Wet 

Weather 

Restrictions would 

be implemented 

on 14 crossings

None
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

436 – Tahoe National Forest

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

NET Cumulative Effect Negative 

cumulative effects.

Cross country 

travel prohibited 

on “0” LCT RCA 

acres.

Motorized travel 

continued on 48 

unauthorized 

native surfaced, 

crossings

No additional 

protection to 

occupied LCT 

streams from wet 

weather 

restrictions.

Least beneficial to 

LCT—results in 55 

crossings in LCT 

watersheds.

Cross country 

travel prohibited 

on 15,437 LCT 

RCA acres.

No additional 

protection to 

occupied LCT 

streams from wet 

weather 

restrictions.

3rd Most beneficial 

alternative. 

Results in the 

least number of 

native surfaced 

crossings (45).

Cross country 

travel prohibited 

on 15,437 LCT 

RCA acres.

No additional 

protection to 

occupied LCT 

streams from wet 

weather 

restrictions.

Most beneficial 

alternative —

results in 48 

crossings in LCT 

watersheds.

Cross country 

travel prohibited 

on 15,437 LCT 

RCA acres.

Reduced 

sedimentation risk 

to occupied LCT 

streams from wet 

weather 

restrictions.

2rd most beneficial 

alternative, shared 

with Alt 6—results 

in 55 crossings in 

LCT watersheds.

Cross country 

travel prohibited 

on 15,437 LCT 

RCA acres.

Reduced 

sedimentation risk 

to occupied LCT 

streams from wet 

weather 

restrictions.

2rd most beneficial 

alternative, shared 

with Alt 5—results 

in 55 crossings in 

LCT watersheds.

Cross country 

travel prohibited 

on 15,437 LCT 

RCA acres.

Reduced 

sedimentation risk 

to occupied LCT 

streams from wet 

weather 

restrictions.

4th most beneficial 

alternative, results 

in 48 crossings in 

LCT watersheds.

Cross country 

travel prohibited 

on 15,437 LCT 

RCA acres.

No additional 

protection to 

occupied LCT 

streams from wet 

weather 

restrictions
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 437

Table 3.03-128. LCT 7th Field Watersheds – Summary of Direct, Indirect, and Cumulative Effect of Proposed Actions as Measured by Native Surfaced, 

Motorized RCA Motorized Miles

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

RCA Acres Prohibited 0 15,437 15,437 15,437 15,437 15,437 15,437

Miles Prohibited 1.6 28.3 29.9 28.3 28.3 28.9 28.3

Native Surfaced, Motorized RCA Routes

Trend of Effect Negative Beneficial Most Beneficial 

alternative

Beneficial Beneficial Beneficial Beneficial

Existing Native Surfaced 

RCA Miles

22.8 22.8 22.8 22.8 22.8 22.8 22.8

Native Surfaced RCA Miles 

Added to NFTS

28.2 1.6 0 1.6 1.6 0.9 1.6

Native Surfaced RCA Miles 

resulting from changed 

maintenance levels (outside 

RCA at Pole Creek)

0 0.5 0 0 0.5 0.5 0

Net NFTS Native Surfaced, 

RCA motorized route miles

51.0 24.9 22.8 24.4 24.9 24.2 24.4

Wet Weather Seasonal 

Restrictions on all Native 

Surfaced Routes

None None None Beneficial - Wet 

Weather 

Restrictions would 

be implemented

Beneficial - Wet 

Weather 

Restrictions would 

be implemented

Beneficial - Wet 

Weather 

Restrictions would 

be implemented

None

NET Cumulative Effect Most negative 

alternative.

Cross country 

travel continues on 

15,437 LCT RCA 

acres, including on 

51 RCA miles. 

No additional 

protection from wet 

weather 

restrictions.

6th most beneficial 

alternative.

Cross country 

travel prohibited on 

15,437 LCT RCA 

acres.

24.9 NFTS RCA 

miles available.

No additional 

protection from wet 

weather 

restrictions.

4th most beneficial 

alternative.

Cross country 

travel prohibited on 

15,437 LCT RCA 

acres 22.8 NFTS 

RCA miles 

available.

No additional 

protection from wet 

weather 

restrictions.

2nd Most beneficial 

alternative.

Cross country 

travel prohibited on 

15,437 LCT RCA 

acres. 

24.4 NFTS RCA 

miles.

Reduced 

sedimentation risk 

to occupied LCT 

streams from wet 

weather restrictions

3rd most beneficial 

alternative.

Cross country 

travel prohibited on 

15,437 LCT RCA 

acres

24.9 NFTS RCA 

miles.available.

Reduced 

sedimentation risk 

to occupied LCT 

streams from wet 

weather restrictions

Most beneficial 

alternative.

Cross country 

travel prohibited on 

15,437 LCT RCA 

acres

24.2 NFTS RCA 

miles available.

Reduced 

sedimentation risk 

to occupied LCT 

streams from wet 

weather restrictions

5th most beneficial 

alternative.

Cross country 

travel prohibited on 

15,437 LCT RCA 

acres

24.4 NFTS RCA 

miles available.

No additional 

protection from wet 

weather 

restrictions.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

438 – Tahoe National Forest

Overall Cumulative Effects of Past, Present, and

Reasonably Foreseeable Future Actions

Past management activities have had severe, adverse cumulative effects on LCT distribution and 

population trends as a result of numerous factors including hybridization and competition with introduced 

trout species; alteration of stream channels and morphology; loss of spawning habitat due to pollution and 

sediment inputs from past logging, mining, and historic grazing, and urbanization; and loss of 

connectivity. LCT was particularly affected within the Truckee River watershed by loss of habitat 

connectivity from water diversions and dam construction (Gerstung 1986 and 1988 and Coffin 1988, In 

USFWS 1995). The Truckee River basin has more than 40 potential barriers to fish migration which have 

impeded LCT migration to historic spawning and rearing habitats. In addition, the resulting reservoirs 

helped to establish a number of non-native fish species known to be detrimental to LCT through predation 

and/or competition.

Livestock grazing has the potential to affect most of the important habitat attributes listed above by 

reducing near-stream vegetation and de-stabilizing stream banks, which can lead to increased stream 

temperature, fine sediment input, and filling of pools. The current occupied LCT recovery streams on the 

Tahoe NF fall within two active livestock allotments - the English Allotment (cattle) and the Sierra Crest 

Allotment (sheep). An Allotment Management Plan for the English Allotment was completed in 1996. 

The Sierra Crest Allotment Management Plan was recently completed. Grazing within the Sierra Crest 

Allotment has not occurred since the early 1990s. Therefore, Austin Meadows and Macklin Creek are the 

only occupied LCT streams that are currently grazed by livestock. Streambank disturbance from livestock 

monitoring at both Austin and Macklin Creek indicate streambank disturbance by livestock have 

generally been within the maximum 10% streambank disturbance guideline for most years monitored, 

with a few exceptions.

The Sierra Nevada Forest Plan Amendment (2004) provides management direction and standards and 

guidelines for livestock utilization and streambank disturbance. Implementation and monitoring of these 

standards and guidelines will likely reduce the potential habitat impacts of livestock grazing. In summary, 

livestock grazing could cumulatively affect LCT habitat and should be limited to Macklin Creek and 

Austin Meadows Creek, though management requirements specific to these activities should limit these 

impacts.

Ongoing and planned vegetation and fuels management projects on National Forest land should not 

add cumulative impacts to effects due implementation of Best Management Practices and Riparian 

Conservation Objectives for Riparian Conservation Areas.

The continuance of cross country travel, including on existing routes unauthorized motorized public 

use, under Alternative 1 poses the greatest risk of adding direct and indirect impacts to existing 

cumulative impacts to streams occupied by LCT within the Independence Lake and the Middle Yuba 

River-Milton Reservoir HUC7 watersheds . Under Alternative 1, HUC7 watersheds occupied by LCT 

would have the highest RCA route densities and the highest route crossing densities as a result of 

unauthorized routes within Riparian Conservation Areas. Under Alternative 1, unauthorized route 

proliferation would likely continue and increase at an accelerated rate in the future, potentially increasing 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 439

sediment delivery and alteration of streambank vegetation and hydrologic condition which may affect the 

abundance of LCT within localized areas in the future. None of the action alternatives proposes to add 

motorized routes or areas to the NFTS within watersheds with occupied LCT streams. Cumulative 

impacts would be added to existing impacts through the change in class of vehicles under Alternatives 2, 

5, and 6, where 0.5 RCA miles and 1 stream crossing could contribute to adverse effects from increased 

sediment delivery. For all the action alternatives, future unmanaged cross country motorized travel would 

be prohibited. In addition, the prohibition of cross country travel would reduce impacts on routes 

unauthorized for motorized public use and benefit LCT in the long-term once these routes are 

rehabilitated through obliteration or other means.

Federally Listed Species Determination

The Biological Assessment, which is incorporated by reference, determined that Alternatives 2, 5, and 6 

may affect, but not likely to adversely affect the federally threatened Lahontan cutthroat trout within the 

Middle Truckee River-Pole Creek 7th field watershed. This determination is based on mitigation 

requirements associated with the proposed change in class of vehicles on 0.5 RCA miles along the Pole 

Creek Road (Road 5708) which has the potential to increase the risk of sediment delivery into Pole Creek, 

an occupied LCT stream. Mitigations measures require that road maintenance standards minimizes 

sediment delivery to Pole Creek. No motorized route or area additions are proposed within any

watersheds with streams occupied by LCT.

Lahontan Lake Tui Chub: Affected Environment

The Lahontan Lake tui chub (Gila bicolor pectinifer) is listed as Sensitive on the Region 5 Forester’s 

Sensitive Species List (USDA Forest Service 1998). The Lahontan Lake tui chub are a cyprinid 

subspecies found in Lake Tahoe and Pyramid Lake (Nevada) which are connected to each other by the 

Truckee River and in nearby Walker Lake (Nevada).

The Lake Tahoe population is the only confirmed population in the Sierra Nevada, with possible 

populations in Stampede, Boca and Prosser Reservoirs on the Truckee Ranger District of the Tahoe 

National Forest. These three reservoirs are connected by the Little Truckee River which feeds into the 

mainstem of the Truckee River. Little study has occurred on the Lake Tahoe population since Miller 

(1951). Zooplankton levels have changed over this period. Daphnia, an important prey of adult chubs, 

have been nearly eliminated (Richards et al. 1975) by the introduced Kokanee salmon (Oncorhynchus 

nerka) and opossum shrimp (Mysis relicta), both of which feed on zooplankton. Marshland degradation 

along the lake may be taking away vital spawning and nursery areas.

Based on occurrence within such widely diverse habitats as Lake Tahoe and Pyramid Lake, it is 

believed this species can tolerate a wide range of physicochemical water conditions. Lahontan Lake tui 

chub are known as a mid-water feeder. In Lake Tahoe, larger fish (>16 cm TL) occur in deeper water 

(>50m) during the day, moving into shallower water areas at night (Miller 1951). Young fish generally 

occur in shallow water. It has also been noted that a seasonal migration occurs within the water column. 

Deeper water in often utilized during winter months and summer months show use of upper portions 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

440 – Tahoe National Forest

(Snyder 1917, Miller 1951). Algal beds in shallow inshore areas seem necessary for spawning, egg 

hatching, and larval survival.

Lahontan Lake tui chub are schooling fish reaching lengths of 35 to 41 cm FL, which inhabit large, 

deep lakes (Moyle 1976, In USFWS 1995). Lahontan Lake tui chub feed primarily on zooplankton, 

especially cladocerans and copepods, but also eat benthic insects when available (Miller 1951, Marrin and 

Erman 1982). Tui chub are predated upon mostly by large trout, and rarely by birds and snakes (Miller 

1951).

In Lake Tahoe, nocturnal spawning occurs during May and June, possibly extending into July (Miller 

1951). Tui chub may be serial spawners, reproducing several times during the spawning season (Moyle 

1976). Reproductive adults spawn near-shore over beds of aquatic vegetation, to which the eggs adhere 

(Snyder 1917). Young remain near-shore until winter when body size is 1-2 cm, and then migrate into 

deeper water. Linear growth of tui chubs occurs within about 4 years, then body mass is accumulated 

rapidly. The largest documented length in Lake Tahoe is 13.7 cm SL, but longer chub (21 cm) have been 

found in Walker Lake, Nevada (Miller 1951).

Potential risk factors include but are not limited to water quality, specifically alkalinity due to 

diversions of inflowing water, change in prey base due to introduced species, and reservoir and wetland 

management.

Lahontan Lake Tui Chub: Environmental Consequences

The actual presence of the Lahontan Lake tui chub on the Tahoe NF has not been confirmed or verified. 

Although its presence has not been confirmed, this analysis assumes the species is present within Boca, 

Stampede and Prosser Reservoirs. Therefore, the analysis for this species was conducted within the three 

7th field watersheds within the Prosser Creek Reservoir HUC7, Stampede Reservoir HUC7, and Boca 

Reservoir HUC7, which includes the three reservoirs and the streams and tributaries that drain into and 

out of them. In addition, to assess a broader and more inclusive analysis of potential indirect effects, RCA 

route density and stream crossing density were analyzed within twelve 7th field watersheds which include 

the three reservoirs and the streams and tributaries that flow into these reservoirs.

Indicators used to Measure Effects

Prosser Creek Reservoir HUC7, Stampede Reservoir HUC7, and Boca Reservoir HUC7

Cross Country Travel: The prohibition of cross country travel is analyzed for the alternatives to estimate 

effects to three tui chub 7th field watersheds from motorized cross country travel.

Additions to the NFTS (tui chub 7th field watersheds): Measures or indicators of changes in 

sedimentation and water surface shade are assessed by analyzing the number of stream crossings 

additions associated with motorized route additions to the National Forest Transportation System, and the 

miles of motorized route additions within Riparian Conservation Areas (RCAs) for tui chub within three 

7th field watersheds where the species has a potential to occur—Prosser Creek Reservoir HUC7, 

Stampede Reservoir HUC7, and Boca Reservoir HUC7.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 441

Establishment of “Open Areas”: The establishment of “Open Areas” at Boca, Stampede, and 

Prosser reservoirs is evaluated under “Effects Common to All Aquatic Species.”

Wet Weather Seasonal Closures: Wet weather seasonal closures are evaluated under “Effects 

Common to All Aquatic Species.”

Change in Class of Vehicles: Changing the class of vehicle on a particular route potentially changes 

the impacts to soil and water resource due to changes in the road surface (i.e. from smooth surfaced to 

rough surfaced) (see Chapter 3.02, Watershed Resources: Geology, Soil, and Hydrology). If the route 

changes from smoothed surfaced to native surfaced (rough surfaced), the change in class of vehicle may 

result in increased sediment and erosion risk to tui chub habitat. The change in class of vehicle and 

associated maintenance downgrades is evaluated for their potential to affect selected 7th field watersheds 

that may have suitable habitat for the tui chub.

Twelve HUC7 Watersheds

Route Density within Riparian Conservation Areas (RCAs): Route densities of native surfaced routes 

within RCAs were evaluated to compare the overall effects of all motorized routes (including existing 

routes and existing routes unauthorized to motorized public use) for the alternatives within twelve 7th field 

watersheds with suitable Lahontan Lake tui chub habitat. According to Chapter 3.02 (Watershed 

Resources: Geology, Soil, Hydrology), native surfaced roads have the greatest potential for off-site 

sediment delivery into streams and lakes. Therefore, this effects analysis includes route density of all 

native surfaced motorized routes. Route density provides a relative index to measure the potential indirect 

effects to suitable tui chub habitat from increased sedimentation from motorized routes. Thresholds for 

route density have not been established, however, route density provides a relative way to compare the 

effects of the alternatives.

Stream Crossing Density: Twelve 7th field watersheds with suitable Lahontan Lake tui chub habitat 

were evaluated for the crossing density of native surfaced motorized routes within RCAs to compare 

direct and indirect effects of motorized routes for the alternatives. Route crossing density provides a way 

to measure the potential direct and indirect effects to the tui chub and habitat. Direct effects include 

potential tui chub mortality as a result of use of motorized crossings that may affect tui chub habitat. 

Indirect effects include changes to channel and streambank characteristics and changes in vegetation 

structure. Thresholds for motorized crossing route density have not been established, however, route 

crossing density provides a relative way to compare the effects of the alternatives.

Direct and Indirect Effects

Cross Country Travel. Under Alternative 1, no action, motorized cross country travel would continue on 

9,689 acres within Riparian Conservation Areas (RCAs) of tui chub HUC7 watersheds, where the 

potential for adversely affecting tui chub habitat could occur by increasing sedimentation and altering 

streamside vegetation. The prohibition of cross country travel results in prohibiting motorized use on 

9,689 RCA acres, including on existing unauthorized routes on between approximately 27.5 to 29 RCA 

miles and between 44 to 48 crossings (Alternative 3- the most, Alternative 5 – the least) for the action 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

442 – Tahoe National Forest

alternatives. The prohibition of motorized cross country travel would likely reduce the risk of 

sedimentation and alteration of streamside vegetation, and therefore benefit potential tui chub habitat.

NFTS Additions and “Open Areas” – Stream Crossings and Miles of Motorized Route Additions

Number of Native Surfaced, Stream Crossing Additions within Three Tui Chub7th Field 

Watersheds. Within the Prosser, Stampede, and Boca Reservoir HUC7 watersheds, the number of native 

surfaced, stream crossings is assessed for the alternatives, and provides a way to compare relative changes 

in sediment into riverine and lacustrine habitats at the HUC 7 watershed scale where potentially suitable 

Lahontan Lake tui chub habitat occurs. Alternative 1 poses the greatest risk of increased sedimentation 

where 42 stream crossings are affected by the continuance of cross country travel on unauthorized 

motorized routes (Table 3.03-129). 

All the action alternatives would benefit tui chub by reducing the number of native surfaced stream 

crossings and motorized route miles within RCAs. Alternatives 2, 4, 5, 6, and 7 would result in the 

addition of between 2-4 motorized native surfaced crossings. Alternative 3 does not add motorized routes 

to the NFTS, and therefore sedimentation or water surface shade would not be affected within the three 

tui chub HUC7 watersheds. 

Table 3.03-129. Lahontan Lake tui chub 7th Field Watersheds (Prosser, Stampede, Boca Reservoirs) - Number 

of Native Surfaced, Stream Crossings Associated with Motorized Route Additions

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Motorized Stream crossings associated with proposed 

motorized route additions (negative impact)

48 3 0 3 4 2 3

*Alternative 1 includes existing native surfaced, stream crossings unauthorized to motorized use, while all the other Alternatives 

include motorized crossing additions.

Miles of Proposed Route Additions within RCAs of Prosser, Stampede, and Boca 7th Field 

Watersheds. The miles of proposed motorized route additions to the NFTS within RCAs were assessed 

for the alternatives, and provide additional information to assess the potential for off-site sediment 

delivery into riverine and lacustrine habitats within tui chub HUC 7 watersheds. Alternative 1 poses the 

greatest risk to increased sedimentation potential from approximately 29 RCA miles of unauthorized 

motorized routes that would remain due to the continuance of cross country travel (Table 3.03-130). 

Similar to stream crossing numbers, the action alternatives would all benefit tui chub by reducing the 

number of miles available for motorized use, therefore reducing the potential for adverse habitat effects 

from erosion and sedimentation. Alternatives 2, 4, 5, 6, and 7 propose to add between 1.0 and 1.7 RCA 

miles of motorized routes, with Alternative 6 adding the least and Alternatives 2, 5, and 7 adding about 

the same amount of miles. Alternatives 3 does not add motorized routes, and therefore changes to 

sedimentation or streamside vegetation would not occur within the three Lahontan Lake tui chub HUC7 

watersheds under these alternatives.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 443

Table 3.03-130. Tui Chub - Miles of Proposed Route Additions within Prosser, Stampede, and Boca HUC7 

Riparian Conservation Areas (RCAs) 

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

RCA Miles of proposed motorized route additions

(negative impact)

29.4 1.6 0 1.6 1.7 1.0 1.6

*Alternative 1 includes existing native surfaced, unauthorized routes, while all the action alternatives include motorized route 

additions.

Changes to the NFTS

Change in Class of Vehicles. For each of the alternatives, Table 3.03-131 displays the effects of proposed 

changes in class of vehicles and the associated change in maintenance standards that have the potential to 

increase the risk of delivering sedimentation and erosion to Prosser, Stampede, and Boca Reservoir HUC7 

watersheds. Alternatives 2, 5, and 6 would result in the change in road maintenance levels resulting in 

changes from smooth surfaced roads to rough surfaced roads that are likely to occur in the future with 

reduced maintenance. This change in road surface type would have a higher potential to result in 

increased sedimentation to tui chub habitat affected by 3 crossings and 1.1 RCA miles under Alternatives 

2 and 5. Alternative 6 would result in less adverse effects to tui chub habitat from 2 native surfaced 

crossings and 0.1 RCA mile. The remaining alternatives would not affect tui chub habitat from changed 

maintenance standards.

Table 3.03-131. Lahontan Lake Tui Chub – Effects from Change in Class of Vehicles

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Number of Native Surfaced Crossings as a result of 

changed maintenance standards from smooth 

surfaced to native surfaced

0 3 0 0 3 2 0

Native surfaced RCA Miles as a result of changed 

maintenance standards from smooth surfaced to 

native surfaced 

0 1.1 0 0 1.1 0.2 0

Reopened ML 1 Roads: None of the alternatives would reopen any ML 1 roads within the three 

Lahontan Lake tui chub HUC7 watersheds within the RCA and therefore would not affect the three HUC7 

tui chub watersheds. 

Tui Chub HUC7 Watersheds

In addition to the motorized routes that can contribute to direct impacts within the three reservoirs, the 

indirect effects of motorized routes to tui chub habitat are analyzed within twelve HUC7 watersheds that 

may contribute to water quality within the reservoirs at a broader landscape scale.

Route Density within Riparian Conservation Areas (RCAs): Riparian Conservation Area (RCA) 

route density for twelve 7th field watersheds on the Tahoe NF are analyzed motorized RCA route density 

(native surfaced) and categorized by four route density categories. Suitable Lahontan Lake tui chub 

habitat was identified to occur within twelve 7th field watersheds on the Tahoe National Forest. For each 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

444 – Tahoe National Forest

of the alternatives, Table 3.03-132 and Figure 3.03-11 display the number and percent of 7th field 

watersheds (HUC7s) with suitable tui chub habitat by RCA route density category of highest (8.9 - 27.3

mi/mi2

), moderately high (6.3 - 8.8 mi/mi2), moderately low (4.3 - 6.2 mi/mi2), and lowest (0.2 - 4.2 

mi/mi2). 

Alternative 1 poses the greatest direct and indirect effects to suitable tui chub habitat where 67% (8 of 

12) tui chub HUC7 watersheds have route densities within the highest, 16% (2 of 12) within moderately 

high, 17% (2 of 12) within moderately low, and none within the lowest route density categories. All the 

action alternatives reduce RCA route densities compared to Alternative 1.

Alternatives 2, 5, and 6 would slightly improve route densities compared to Alternative 1, where tui 

chub HUC7 watersheds would result in 5 watersheds in the highest, 4 in the moderately high, 1 in the 

moderately low, and 2 in the lowest route density category. 

Alternatives 3, 4, and 7 have the lowest route densities of all the action alternatives, where 3 HUC7 

watersheds are in the highest route density categories, 5 are in the moderately high, 2 in the moderately 

low, and 2 are in the lowest density categories.

Table 3.03-132. Number of HUC7 Watersheds with Suitable Lahontan Lake Tui Chub Habitat by RCA Route 

Density Category

Alternatives Highest

(8.9 - 27.3 mi/mi2

)

Moderately High

(6.3 - 8.8 mi/mi2)

Moderately Low

(4.3 - 6.2 mi/mi2)

Lowest

(0.2 - 4.2 mi/mi2)

Alt 1 8 2 2 0

Alt 2 5 4 1 2

Alt 3 3 5 2 2

Alt 4 3 5 2 2

Alt 5 5 4 1 2

Alt 6 5 4 1 2

Alt 7 3 5 2 2
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 445

Native Surface, Motorized RCA Route Density - HUC7s with Suitable Lahontan Lake Tui Chub Habitat

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Alternative

Percent of Watersheds with Suitable Chub and GBS 

Habitat

highest (8.9 - 27.3)

moderatley high (6.3 - 8.8)

moderately low (4.3 - 6.2)

lowest (0.2 - 4.2)

Figure 3.03-11. Proportion of HUC7 Watersheds with Suitable Lahontan Lake Tui Chub Habitat by Motorized 

RCA Route Density Categories 

Stream Crossing Density: Twelve 7th field watersheds (HUC7s) identified as potential habitat for the 

Lahontan Lake tui chub within the three reservoirs were evaluated by alternative for the number and 

percentage of HUC7s that are within stream crossing density categories of highest (8.9 – 27.3 

crossings/mi2

), moderately high (6.3 - 8.8crossings/mi2), moderately low (4.3 - 6.2 crossings/mi2), and 

lowest (0.2 - 4.2 crossing/mi2 (Table 3.03-133 and Figure 3.03-12). Alternative 1 poses the greatest risk of 

direct and indirect effects to Lahontan Lake tui chub habitat through potential sediment delivery from 

native surfaced, motorized routes. Under Alternative 1, 100% HUC7 watersheds potentially affecting tui 

chub habitat would have stream crossing densities within the highest and the moderately high route 

density categories combined. 

All the action alternatives would benefit tui chub habitats by reducing the native surfaced crossing 

densities within the 12 tui chub HUC7 watersheds. Of the action alternatives, Alternative 5 has a higher 

proportion of tui chub HUC7 watersheds in the highest stream crossing density category (67% or 8 of 12), 

under Alternative 5, and 2 watersheds each in the moderately high and the moderately low crossing 

density categories.

The remaining alternatives would further reduce the number of stream crossings within the highest 

crossing density categories. Alternatives 2 and 7 would have the same proportion of HUC7 watersheds 

within stream crossing density categories. Alternative 6 follows Alternatives 2 and 7, and Alternative 3 

has the lowest stream crossing densities with the highest number of HUC7 watersheds within the 

moderately low and the lowest crossing density categories compared across all the alternatives.
 

 

 

Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010 

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species 

Native Surface, Motorized Stream Crossing Density -

HUC7s w ith Suitable Lahontan Lake Tui Chub Habitat 

0% 

10% 

20% 

30% 

40% 

50% 

60% 

70% 

80% 

90% 

100% 

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7 

A lt ernat ives 

highest (8.9 - 27.3) 

moderately high (6.3 - 8.8) 

moderately low (4.3 - 6.2) 

lowest (0.2 - 4.2) 

Percent of Watersheds with suitable Lahontan 

Lake Tui Chub Habitat 

Figure 3.03-12. Number of HUC7 Watersheds with suitable Lahontan Lake Tui Chub Habitat by Motorized 

Stream Crossing Density Categories 

Table 3.03-133. Number and percent of HUC7 Watersheds with Suitable Lahontan Lake Tui Chub Habitat by 

Native Surfaced, Motorized Stream Crossing Density Category 

Alternatives Highest Moderately High Moderately Low Lowest 

8.9 – 27.3 crossings/mi2

) (6.3 - 8.8crossings/mi2) (4.3 - 6.2 crossings/mi2) (0.2 - 4.2 crossing/mi2) 

Alt 1 

Alt 2 

Alt 3 

Alt 4 

Alt 5 

Alt 6 

Alt 7 

9 

6 

6 

6 

8 

6 

6 

3 

4 

4 

4 

2 

3 

4 

0 

2 

1 

2 

2 

2 

2 

0 

0 

1 

0 

0 

1 

0 

Cumulative Effects 

Cumulative Effects Boundary in Space and Time 

The geographic boundary for assessing cumulative effects to the Lahontan Lake tui chub on the Tahoe NF 

is within the nine 7th field watersheds that may potentially indirectly impact suitable habitat for the 

species. Suitable habitat for this species occurs within Stampede, Boca, and Prosser reservoirs and 

streams that feed or connect to these reservoirs. This cumulative effects boundary is sufficiently large to 

assess all past, present, and future cumulative impacts to suitable habitat for the Lahontan Lake tui chub. 

Any larger boundary could dilute the effects of past, present, and future cumulative impacts to this 

species. The timeframe for assessing cumulative impacts in the past includes activities that occurred 

within the last 50 to 100 years. Reasonably foreseeable future impacts expand out to approximately 20 

years into the future. 

446 – Tahoe National Forest 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 447

Cumulative Effects of Past, Present, and Reasonably Foreseeable Actions

The current knowledge of the species distribution on the Tahoe NF is unknown. Suitable habitat for the 

Lahontan Lake tui chub on the Tahoe NF is considered to be Stampede, Boca, and Prosser Reservoirs and 

the streams connecting them (Little Truckee River and tributaries). Potential past cumulative effects to 

this species includes habitat degradations from water diversions, reduced water quality, urbanization, 

livestock grazing, recreational activities, and others. The fact that the occurrence of the species on the 

Tahoe NF is unknown makes assessing cumulative effects extremely difficult. Therefore, there is a great 

deal of uncertainty surrounding the past cumulative effects to this species from past, present, and 

reasonably foreseeable future activities. Any attempt to actually describe cumulative impacts would be 

speculative at best, since it is unknown whether or not this species has a historical distribution on the 

Tahoe NF.

Under Alternative 1, cumulative effects from continued cross country travel, including on 48 native 

surfaced crossings and approximately 29 miles of unauthorized routes would be greatest where HUC7 

watersheds with suitable tui chub habitat would have the highest RCA route densities and the highest 

route crossing densities. The indirect impacts of potential sediment delivery from existing motorized 

unauthorized routes in Alternative 1 would add measurable cumulative impacts to suitable Lake Lahontan 

tui chub habitat where 83% of HUC7 watersheds route densities are within the highest and moderately 

high route density categories combined. In addition, native surfaced, motorized stream crossing densities 

would be greatest under Alternative 1 where 100% of the HUC7 watersheds are within the high and 

moderately highest stream crossing categories combined. The remaining alternatives improve both route 

density within Riparian Conservation Areas and stream crossing densities with Alternative 5 reducing the 

least and Alternatives 2, 3, 4, 6, and 7 reducing the most.

For all the action alternatives, future unmanaged cross country motorized travel would be prohibited 

on 9,689 acres, including on approximately 27-29 RCA miles of existing unauthorized motorized routes 

and on 44-48 native surfaced, stream crossings (Alternative 5 prohibits the least, Alternative 3 prohibits 

the most). These cross country prohibitions would likely benefit suitable tui chub habitat in the long-term 

once these routes are rehabilitated through active or passive restoration efforts.

Summary of Direct, Indirect, and Cumulative Effects of Proposed Actions

Table 3.03-134 summarizes the direct, indirect, and cumulative effects to native surfaced, motorized route 

crossings and RCA miles within Lahontan Lake tui chub HUC 7 watersheds, from existing motorized 

system routes, motorized route additions, and existing unauthorized routes from the proposed alternatives, 

wet weather seasonal restrictions, changes in class of vehicles, prohibition of cross country travel. See 

Chapter 3.02 (Watershed Resources: Geology, Soil, Hydrology) for more detailed information and 

assumptions.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

448 – Tahoe National Forest

Table 3.03-134. Lahontan Lake Tui Chub 7th Field Watersheds – Summary of Direct, Indirect, and Cumulative Effect of Proposed Actions 

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross 

Country 

Travel 

Prohibitions 

(acres)

Trend of 

Effect

Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres 0 7,100 9,689 9,689 9,689 9,689 9,689

Crossings 0 45 48 45 44 46 45

RCA Miles 1.0 27.8 29.3 27.8 27.6 28.4 27.5

Existing NFTS 

Native 

Surfaced, 

Motorized 

Routes 

Crossings 35 35 35 35 35 35 35

Miles 21.5 21.5 21.5 21.5 21.5 21.5 21.5

Native 

Surfaced, 

Motorized 

Route 

Additions to 

the NFTS*

Trend of 

Effect

Negative 3rd most 

beneficial 

alternative, 

shared with Alts 

4 and 7.

Most benefical 

alternative

3rd most beneficial 

alternative, shared 

with Alts 2 and 7.

Least beneficial 2nd most beneficial 

alternative

3nd most beneficial 

alternative, shared 

with Alts 2 and 4.

Crossings 48 3 0 3 4 2 3

Miles 29.4 1.6 0 1.6 1.7 1.0 1.6

Change in 

Class of 

Vehicles 

Resulting in 

Changed 

Maintenance 

Standards 

Trend of 

Effect

No Effect Negative No Effect No Effect Negative Negative No Effect

Crossings 0 3 0 0 3 2 0

RCA Miles 0 1.1 0 0 1.1 0.2 0

Reopened ML 1 Roads 0 0 0 0 0 0 0

Total Native 

Surfaced, 

Motorized 

Routes

Crossings 83 38 35 38 39 37 38

RCA Miles 50.9 25.2 21.5 23.1 25.3 23.6 23.1

Establishment

of “Open 

Areas” 

(Prosser, 

Stampede, and 

Boca 

Reservoirs)

Trend of 

Effect

Negative – cross 

country travel 

continued

Negative No Effect No Effect No Effect Slight to none, 

designation on 

specific areas that 

have been 

stabilized or 

mitigated

No Effect

Acres 0 2,589 0 0 0 244 0
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 449

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Wet Weather 

Seasonal 

Restrictions 

on all Native 

Surfaced 

Roads and 

Routes

Trend of 

Effect

Negative Negative Negative Beneficial Beneficial Beneficial Negative

Description No wet weather 

restrictions on 

high risk 

crossings.

No wet weather 

restrictions on 

high risk 

crossings.

No wet weather 

restrictions on 

high risk 

crossings.

Wet Weather 

Restrictions would be 

implemented on 

native surfaced 

crossings reducing 

erosion risk

Wet Weather 

Restrictions would be 

implemented native 

surfaced crossings 

reducing erosion risk

Wet Weather 

Restrictions would be 

implemented native 

surfaced crossings 

reducing erosion risk

No wet weather 

restrictions on high 

risk crossings.

NET Cumulative Effect Most negative 

alternative with 

motorized 83 

crossings and 

50.9 RCA miles.

Cross country 

travel continues 

on 9,689 tui chub 

RCA acres

No additional 

protection to tui 

chub habitat from 

wet weather 

restrictions.

Least beneficial 

alternative.

Cross country 

travel prohibited 

on 9,689 tui 

chub RCA 

acres

Potentially 

increases 

sedimentation 

to habitat within 

open reservoir 

areas 

No additional 

protection to tui 

chub habitat 

from wet 

weather 

restrictions.

4th most benefical 

alternative.

Cross country 

travel prohibited 

on 9,689 tui chub 

RCA acres.

No additional 

protection to tui 

chub habitat from 

wet weather 

restrictions

Most beneficial 

alternative, shared 

with Alt 7. 

Cross country travel 

prohibited on 9,689 tui 

chub RCA acres 

Reduced 

sedimentation risk to 

tui chub habitat from 

wet weather 

restrictions

3rd most beneficial 

alternative.

Cross country travel 

prohibited on 9,689 tui 

chub. RCA acres.

Reduced 

sedimentation risk to 

tui chub habitat from 

wet weather 

restrictions

2nd most beneficial 

alternative.

Cross country travel 

prohibited on 9,689 tui 

chub. RCA acres.

Reduced 

sedimentation risk to 

tui chub habitat from 

wet weather 

restrictions

Most beneficial 

alternative, shared 

with Alt 4. 

Cross country travel 

prohibited on 9,689 

tui RCA acres 

Reduced 

sedimentation risk to 

tui chub habitat from 

wet weather 

restrictions

*Alternative 1 includes existing native surfaced, stream crossings unauthorized to motorized use, while all the other Alternatives include motorized crossing additions.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

450 – Tahoe National Forest

Frogs

Potential road and trail associated risk factors to the suitable habitat for frogs, particularly California redlegged frogs, foothill yellow-legged frogs, and mountain yellow-legged frogs, can cause the modification 

or loss of habitat or habitat components, primarily aquatic and adjacent riparian environments used for 

reproduction, cover, foraging, and aestivation. Egg survival can be impacted by roads and trails through 

increases in fine sediments. Stream crossings and roads and trails that are within close proximity to 

streams and ponds have the potential to impact riparian vegetation, emergent vegetation, nutrient loading, 

and channel morphology and hydrology that are important habitat components for frog species.

The degree to which trails and roads affect frogs and their habitat depends on many factors such as 

road density, road type, and traffic intensity. Most studies on road and trail associated factors address 

other amphibians (e.g., Fahrig et al. 1995, Mazerolle 2003, 2004). Several studies have shown that 

amphibian densities are inversely related to road density and traffic intensity (see Fahrig et al. 1995, Vos 

and Chardon 1998).

Direct impacts to frog populations from roads potentially include road mortality, direct loss of habitat, 

or creation of barriers. Mass mortalities of other species of frogs have been documented during dispersal 

where roads intersect natal/breeding habitat and non-breeding foraging habitat (Hine et al. 1981, Fahrig et 

al. 1995; see also Trombulak and Frissell 2000). Mortality from vehicles can reduce population size and 

reduce movement between resources and conspecific populations (Carr and Fahrig 2001). Road mortality 

is a considerable potential risk factor for foothill yellow-legged frogs because roads are common over the 

areas encompassing their historical range on the Tahoe NF, many of the roads presently have at least 

moderate traffic levels; and some observations suggest upslope seasonal movements by frogs likely 

intersect roads.

Roads can also impact populations of frogs by affecting their riparian or terrestrial habitat. Trombulak 

and Frissell (2000) identified eight physical characteristics of the environment may be altered by roads: 

soil density, temperature, soil water content, light, dust, surface-water flow, pattern of run-off, and 

sedimentation. The presence of roads is highly correlated with changes in the hydrologic and geomorphic 

processes that affect aquatic and riparian systems (Trombulak and Frissell 2000). Roads can influence 

both peak flows (floods) and debris flows (rapid movements of soil, sediment, and large wood stream 

channels) two processes which have major influences on riparian vegetation (Jones et al. 2000) as well as 

aquatic and riparian patch dynamics critical to stream ecosystems (Pringle et al. 1988). California redlegged frogs, foothill yellow-legged frogs, and mountain-yellow legged frogs breed in streams, which can 

be affected by fluctuations in the frequency or magnitude of peak and debris flows of adjacent streams. 

Fluctuations causing reductions or excesses in available water could severely affect recruitment. 

Hydrologic effects are likely to persist for as long as the road remains a physical feature altering flow 

routing - often long after abandonment and revegetation of the road surface (Trombulak and Frissell 

2000).

Increased sedimentation from roads also impacts riparian habitat used by frogs. The knowledge of the 

impact of increased sediment load on amphibians is limited (Gillespie 2002). However, the negative 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 451

impacts of increased sediments on aquatic species, including fish, macroinvertebrates, and periphyton, are 

well known (Power 1990, Newcombe and MacDonald 1991, Waters 1995). The transfer of sediment to 

streams and other water bodies at road crossings is also a consequence of roads and trails (Richardson et 

al. 1975). The surfaces of unpaved roads can route fine sediments to streams, lakes, and wetlands, 

increasing turbidity of the water (Reid and Dunne 1984). This disrupts stream ecosystems by inhibiting 

aquatic plants, macro-invertebrates, and fish. High concentrations of suspended sediment may directly kill 

aquatic organisms and impair aquatic productivity (Newcombe and Jensen 1996). The effects are 

heightened if the sediments contain toxic materials (Maxell and Hokit 1999, In Joslin and Youmans 

1999). Increased sedimentation may also reduce availability of important food resources for tadpoles such 

as algae (Power 1990). Fine sediment deposits also tend to fill pools and smooth gravel beds, degrading 

habitats (Forman and Alexander 1998) and possibly the availability of oviposition sites or larval refugia 

(Welsh and Ollivier 1998). In addition, the consequences of past sedimentation are long term and 

cumulative, and cannot be mitigated effectively (Hagans et al. 1986). The only data addressing 

sedimentation effects on foothill yellow-legged frogs are from Oregon, where sedimentation emerged as 

one of the variables affecting foothill yellow-legged frog occupancy (Borisenko and Hayes 1999).

The spread of chemicals is another way in which roads may impact frog. At least five different 

general classes of chemicals are transferred into the environment from maintenance and use of roads: 

heavy metals, salt, organic molecules, ozone, and nutrients (Trombulak and Frissell 2000). The change of 

the chemical environment by roads may affect living organisms in several ways. For example, chemicals 

found in road de-icers may kill (Dougherty and Smith 2006) or displace frog life stages, or they may be 

accumulated in plants as toxins which, in turn, can depress larval amphibian growth. Another example is 

the historical use of lead as a fuel additive that may have affected foothill yellow-legged frogs because 

lead has been shown to have sub-lethal effects on growth and behavior of northern leopard frog larvae 

(Chen et al. 2006). No data exist that specifically addresses the effects of road associated chemicals on 

California red-legged frogs, foothill yellow-legged frogs, or mountain yellow-legged frogs.

California Red-legged Frog: Affected Environment

The U. S Fish and Wildlife Service listed the California red-legged frog (Rana aurora draytonii) (CRLF) 

as federally threatened in 1996. The western portion of the Tahoe National Forest falls within the Sierra 

Nevada recovery unit (Recovery Unit #1) (USDI Fish and Wildlife Service 2002). The Plumas and Tahoe 

National Forests share Core Area #2 Yuba River-South Fork Feather River located in Yuba County (USDI 

Fish and Wildlife Service 2002). This core area includes a portion of the North Yuba River around New 

Bullards Bar Reservoir. Recovery actions would be focused within core areas. No critical habitat is 

designated on the Tahoe National Forest (USDI Fish and Wildlife Service 2001) (Federal Register 66 

(49): 14626-14758).

The California red-legged frog is a highly aquatic species typically found in cold water ponds and 

stream pools with depths exceeding 0.7 meters and with overhanging vegetation such as willows, as well 

as emergent and submergent vegetation (Hayes and Jennings 1988). It is generally found at elevations 

below 4,000 feet. Suitable California red-legged frog breeding habitat on the Tahoe NF includes all 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

452 – Tahoe National Forest

ponds, lakes and reservoirs on the west slope of the forest that contain water through July in years with 

average precipitation, and low gradient stream reaches (< 4 percent) that do not receive peak runoff flows 

from snowmelt during May or June. Sites need to provide: suitable water depth for breeding (most years), 

presence of still or slow moving water, good water temperature for egg laying and larval development, 

presence of emergent aquatic vegetation or woody debris for egg deposition braces.

California red-legged frog are not currently known to occur on the Tahoe NF, though four known 

populations are located adjacent to the Tahoe NF administered lands. In 2000, red-legged frogs were 

found in Little Oregon Creek, a tributary to New Bullards Bar Reservoir on the Plumas NF. The Little 

Oregon Creek population is approximately 1 mile from New Bullards Bar Reservoir. In 2001 a single 

female was located in Spivey Pond on the Eldorado NF on Ralston Ridge, located 1 mile from the Tahoe 

NF boundary. A third population was found in 2003 on private land within the Rock Creek watershed near 

Nevada City, within 1/5 miles of the Tahoe NF boundary. In 2006, a fourth site consisting of 

approximately 50 individuals was discovered on private land near Michigan Bluff in the Big Gun 

Diggings area. From 1996 to present, suitable California red-legged frog habitat on the Tahoe NF has 

been surveyed to U.S. Fish and Wildlife Service protocol at approximately 100 sites. To date, no 

California red-legged frog sites have been detected on lands administered by the Tahoe NF.

Roads in close proximity to streams also increase the potential for human disturbance of aquatic 

species and their habitats. In general, such disturbance would be correlated to the type of disturbance 

(e.g., roadside hazard tree removal, collection of aquatic species, behavioral changes in response to noise, 

etc.), the intensity of that disturbance, and the distance of the road from the stream. 

Roads and trails can increase the risk of modification or loss of red-legged frog habitat or habitat 

components, primarily aquatic and adjacent riparian environments used for reproduction, cover, foraging, 

and aestivation. Egg survival can be impacted by road and trail associated factors through increases in 

fine sediments and changes in channel morphology and hydrology (SNFPA 2001), thus adversely 

affecting habitat and potentially disrupting amphibian reproduction. Effects of increased sediment 

delivery to aquatic systems include adverse effects to water quality (e.g., increases in turbidity) and 

changes in substrate composition morphology that potentially could influence in-stream primary 

production and macroinvertebrate assemblages. Such changes could alter the prey species 

presence/absence and/or promote changes in habitat that favor non-native species that have a negative 

effect on the red-legged frog.

California Red-legged Frog: Environmental Consequences

In 2006, the U.S. Forest Service entered into programmatic consultation with the U.S. Fish and Wildlife 

Service for route designation (travel management) for motor vehicles in 14 National Forests in California. 

The BE for the Tahoe NF Motorized Travel Management Project and this programmatic consultation is 

incorporated by reference. Project design criteria were developed jointly, which includes measures to 

avoid impacts to federally listed species, including the California red-legged frog. The U.S. Fish and 

Wildlife Service has agreed that, by using the Project Design Criteria for each of the Threatened and 

Endangered species and Critical Habitat, route designation will meet “No Effect” or “May Affect Not 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 453

Likely to Adversely Affect” determinations and that they would concur with these determinations on a 

programmatic basis. Forest consultation can tier to the programmatic consultation with no further 

consultation.

The following project design criteria were developed specifically for the California red-legged frog to 

achieve a “No Effect” or “May Affect Not Likely to Adversely Affect” determination for routes 

(motorized road or trail) and area additions to the NFTS:

1. Routes or areas do not have the potential to capture surface run-off and then deliver sediment 

into a stream associated with California red-legged frog.

2. In suitable California red-legged frog habitat, routes avoid Riparian Conservation Areas except 

where necessary to cross streams. Crossing approaches get the riders in and out of the stream 

channel and riparian area in the shortest distance possible while meeting the gradient and 

approach length standards. 

3. Routes or areas that cross any stream or waterbody within 150 m (500 ft) of known occupied 

sites of California red-legged frog; and route or area is not within a distance of 150 m (500 ft) 

from wetlands (i.e. springs, wet meadows, ponds, marshes).

4. In habitat occupied by California red-legged frog, routes or areas do not have the potential to 

capture or divert stream flow. The approaches to stream crossings are downsloped toward the 

stream on both sides.

5. Routes or areas are located outside of Critical Aquatic Refuges, Riparian Conservation Areas, 

meadows, and wetlands within California red-legged frog habitat.

6. No route or areas are within Critical Aquatic Refuges for California red-legged frog.

Direct and Indirect Effects

There are no known occupied California red-legged frog sites on lands administered by the Tahoe NF. 

Proposed motorized route and area additions to the NFTS do not directly, indirectly, or cumulatively 

impact the California red-legged frog. All the action alternatives would be consistent with the above 

Project Design Criteria, since none of the proposed route or area additions would adversely affect any 

occupied California red-legged frog sites adjacent to or within the boundary of the Tahoe NF. 

The North Bloomfield (Rock Creek) red-legged frog site occurs several miles outside of the Forest 

boundary just north of Nevada City, and would not be affected by the proposed route and area additions. 

Two other known red-legged sites are on the Eldorado and Plumas NFs, and would not be affected by this 

project. The occupied California red-legged frog site near Michigan Bluff is immediately adjacent to the 

Forest boundary. No routes would be proposed within proximity to the Michigan Bluff site.

• Routes or areas do not have the potential to capture surface run-off and then deliver sediment into 

a stream associated with California red-legged frog.

No routes would be proposed within proximity to any of the CRLF occupied habitats discussed 

above.

• In suitable California red-legged frog habitat, routes avoid Riparian Conservation Areas except 

where necessary to cross streams. Crossing approaches get the riders in and out of the stream 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

454 – Tahoe National Forest

channel and riparian area in the shortest distance possible while meeting the gradient and approach 

length standards. 

No routes would be proposed within proximity to any of the CRLF occupied habitat.

• Routes or areas that cross any stream or waterbody within 150 m (500 ft) of known occupied sites 

of California red-legged frog; and route or area is not within a distance of 150 m (500 ft) from 

wetlands (i.e. springs, wet meadows, ponds, marshes).

No routes would be proposed for addition or reopened within proximity to any of the CRLF 

occupied habitat.

• In habitat occupied by California red-legged frog, routes or areas do not have the potential to 

capture or divert stream flow. The approaches to stream crossings are downsloped toward the 

stream on both sides.

No routes would be proposed for addition or reopened within proximity to any of the CRLF 

occupied habitat.

• Routes or areas are located outside of Riparian Conservation Areas, meadows, and wetlands 

within California red-legged frog habitat.

No routes would be added or reopened within proximity to any of the CRLF occupied habitat.

• No route or areas are within Critical Aquatic Refuges for California red-legged frog.

The two Critical Aquatic Refuges (CARs) on the Tahoe NF, located at Sierra Buttes and 

Independence Lake, are outside the range of the California red-legged frog.

Cumulative Effects

Cumulative Effects Boundary in Space and Time

The geographic boundary for assessing cumulative effects to the California red-legged frog (CRLF) is the 

west side of the Tahoe NF below 4,000 feet within ponds and streams with a gradient < 4%, since this is 

within habitat that is considered suitable on the Tahoe NF. This geographic boundary is sufficiently large 

to encompass historic and potential CRLF habitat on the Tahoe NF. Any larger boundary could dilute the 

effects of past, present, and future cumulative impacts to this species. The timeframe for assessing 

cumulative impacts in the past includes activities that occurred within the last 50 to 100 years. 

Reasonably foreseeable future impacts expand out to approximately 20 years into the future.

Cumulative Effects of Past, Present, and Reasonably Foreseeable Future Actions

The California red-legged frog was once numerous and widely distributed in California. Initial declines of 

the California red-legged frog is attributed to over-harvesting (Jennings and Hayes 1985), and then later 

to the introduction of the bullfrog which have out-competed and predated on the CRLF. A variety of other 

past cumulative impacts to California red-legged frogs have affected the distribution and abundance of the 

California red-legged frog on the Tahoe NF, including historic mining and grazing; urban development 

and mining on private land; road building, water diversions; recreation and non-native species 
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Tahoe National Forest – 455

introduction. All these activities have the potential to alter California red-legged frog habitat through 

disturbance to vegetation, soils, hydrology, and the potential for introduction of exotic species. Activities 

on private land that comprise a significant checkerboard pattern on the Tahoe NF will continue to affect 

the species.

Thirty two of fifty-nine total ponds that have been identified as suitable red-legged frog habitat occur 

within active livestock allotments on the Tahoe NF. Since occupied CRLF habitat does not currently occur 

on the Tahoe NF, none of the current active grazing allotments has the potential to contribute to 

cumulative effects to occupied CRLF habitat. However, suitable California red-legged frog habitat 

overlaps with 13 active grazing allotments where habitat degradation to suitable habitat could occur.

Although mining activities have the potential to adversely affect this species, suitable habitat has been 

created for this species (i.e. Michigan Bluff private land historic mine tailing ponds).

The proposed alternatives, including the No Action Alternative, would not directly or indirectly add 

impacts to any existing cumulative impacts to the California red-legged frog, since no California redlegged frog populations occur on NFS lands within the boundary of the Tahoe NF. The nearest known 

populations of California red-legged frog occur on private lands adjacent to Forest Service system lands 

in the vicinity of North Bloomfield, Nevada City, the Michigan Bluff area near the town of Foresthill, and 

within the Eldorado NF in Spivey Pond.

Foothill Yellow-legged Frog: Affected Environment

Introduction: The foothill yellow-legged frog (Rana boylii) (FYLF) is listed as Sensitive on the Region 5 

Forester’s Sensitive Species List (USDA Forest Service 1998). Foothill yellow-legged frogs are 

associated with streams in a variety of habitats including riparian, mixed conifer, and wet meadow types 

(Stebbins 1985). To varying degrees depending on life stage, their habitat requirements are closely linked 

to seasonal variation in stream habitats and comprise three categories: breeding and rearing habitat, nonbreeding active-season habitat; and over wintering habitat. Breeding and rearing habitat is located in 

gently flowing water. Foothill yellow-legged frogs breed at locations with substrates and channel shapes 

that provide suitable velocities and depths over a relatively broad range of discharge volumes (Kupferberg 

1996a). These frogs prefer partial shade, shallow riffles, and cobble sized or greater substrate (Hayes and 

Jennings 1988). Occasionally, this species is also found in other riparian habitats, including moderately 

vegetated backwaters, isolated pools, (Hayes and Jennings 1988, pers. obs.), and slow moving rivers with 

mud substrates (Fitch 1938). During breeding and summer, FYLF are rarely encountered far from 

permanent water. During the winter, frogs have been observed in abandoned rodent burrows and under 

logs as far as 100 meters from a stream (Zeiner et al. 1988).

Private lands comprise the largest fraction (about 50 percent) of historic foothill yellow-legged frog 

range in the Sierra Nevada. Only about 25 percent of historic FYLF range occurs on NFS lands, they are 

not documented from Wilderness Areas or National Park lands in the Sierra Nevada, where roads are few. 

The remaining 25 percent of FYLF habitat lies on state lands, other federal lands (e.g., Bureau of Land 

Management [BLM], Bureau of Reclamation [BOR]), or tribal lands. On the Tahoe NF suitable habitat 
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456 – Tahoe National Forest

for FYLF is considered to be streams occurring below 6,000 feet elevation on the westside of the Tahoe 

NF. 

Risk factors to the FYLF include disease, introduced fish and other exotic (bullfrog) and native 

predators, airborne contaminants (including pesticides), livestock grazing, recreational activities

(including activities associated with motorized routes), water development and diversion, vegetation and 

fuels management projects, and habitat loss and fragmentation.

Motorized Route Associated Risk Factors: As indicated above, recreational activities associated 

with motorized routes has the potential to adversely affect FYLF and their habitat. Roads and trails have 

the potential to directly affect FYLF populations by road or trail mortality, direct habitat loss, and/or the 

creation of barriers. Mortality from vehicles can reduce FYLF population size and reduce movement 

between breeding and over wintering sites. Route associated mortality is a considerable potential risk 

factor for FYLF because roads are common over the areas encompassing their historical range on the 

Tahoe NF; and many of the roads presently have at least moderate traffic levels; and some observations 

suggest upslope seasonal movements by FYLF likely intersect roads.

Foothill Yellow-legged Frog: Environmental Consequences

Indicators used to Measure Effects

Cross Country Travel: The prohibition of cross country travel is analyzed for the alternatives to estimate 

the potential benefits and reduction in effects to FYLF 7th field watersheds from motorized cross country 

travel.

NFTS Additions and Establishment of “Open Areas” (FYLF 7th field watersheds): Measures or 

indicators of changes in sedimentation and water surface shade are assessed by analyzing the number of 

stream crossings additions associated with motorized route additions to the NFTS and the miles of 

motorized route additions within Riparian Conservation Areas (RCAs) for FYLF 7th field watersheds. The 

establishment of motorized “open areas” is also analyzed.

Site-specific Physical Impacts and Disturbance to known foothill yellow-legged frog locations: 

Proposed motorized route additions were evaluated to determine site-specific impacts to known FYLF 

locations for each of the alternatives. Native surfaced routes that cross or intersect FYLF streams and 

ponds have the greatest potential to disturb FYLF, kill and crush FYLF egg masses and to alter stream 

banks and deliver sediment which can degrade FYLF habitat condition. In addition, any proposed 

motorized route additions that are within RCAs or has the potential to delivery sediment to known FYLF 

locations were also evaluated by the alternatives.

Changes to the NFTS

Change in Class of Vehicles: Changing the class of vehicle on a particular route potentially changes the 

impacts to soil and water resource due to changes in the road surface (i.e. from smooth surfaced to rough 

surfaced) (see Chapter 3.02, Watershed Resources: Geology, Soil, and Hydrology). If the route changes 

from smoothed surfaced to native surfaced (rough surfaced), the change in class of vehicle may result in 

increased sediment and erosion risk to FYLF habitat. The change in class of vehicle and associated 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 457

changed maintenance standards is evaluated for their potential to affect selected 7th field watersheds that 

may have suitable habitat for the FYLF.

Wet Weather Seasonal Closures: Proposed wet weather seasonal restrictions on native surfaced 

roads and trails are analyzed in the section “Effects Common to All Aquatic Species.”

Reopened ML 1 Roads: No ML 1 roads are proposed for reopening within FYLF watersheds that 

would affect RCAs or would cross any FYLF streams. Therefore, effects to FYLF would not occur from 

reopening ML 1 roads.

Route Density within Riparian Conservation Areas (RCAs): Route densities of native surfaced 

routes within RCAs were evaluated to compare the overall effects of all motorized routes (including 

existing NFTS routes and existing unauthorized routes) for the alternatives within each 7th field watershed 

occupied by foothill yellow-legged frog (FYLF). According to Chapter 3.02 (Watershed Resources: 

Geology, Soil, Hydrology), native surfaced motorized routes have the greatest potential for off-site 

sediment delivery into streams and lakes. Therefore, this effects analysis includes route density of all 

native surfaced motorized routes maintained for high clearance vehicles. Route density provides a relative 

index to measure the potential indirect effects to occupied habitat of FYLF from increased sedimentation 

from routes. Thresholds for route density have not been established, however, route density provides a 

relative way to compare the effects of the alternatives.

Stream Crossing Density within Riparian Conservation Areas (RCAs): The 7th field watersheds 

occupied by FYLF were evaluated for the crossing density of native surfaced motorized routes within 

RCAs to compare direct and indirect effects of motorized routes for the alternatives. Route crossing 

density provides a way to measure the potential direct and indirect effects to FYLF and habitat. Direct 

effects include potential FYLF mortality as a result of use of motorized crossings of occupied FYLF 

streams. Indirect effects include changes to channel and streambank characteristics and changes in 

vegetation structure. Thresholds for motorized crossing route density have not been established, however, 

route crossing density provides a relative way to compare the effects of the alternatives.

Direct and Indirect Effects

Cross Country Travel. Under Alternative 1, no action, motorized cross country travel would continue on 

34,092 Riparian Conservation Areas (RCAs) acres within FYLF HUC7 watersheds, where the potential 

for adversely affecting FYLF habitat could occur by increasing sedimentation and altering streamside 

vegetation. Alternative 1 would prohibit 8 RCA miles and 19 crossings that were closed from previous 

NEPA decisions (Table 3.03-135).

The action alternatives would all benefit FYLF habitats from the prohibition of cross country travel 

and would result in prohibiting motorized use on 34,092 RCA acres. The action alternatives also prohibits 

motorized use on the 8 RCA miles and 19 crossing that were closed from previous NEPA decisions, but 

also prohibits cross country travel on existing unauthorized routes for a combined total of 57.0 to 71.2

RCA miles and 186 to 228 motorized crossings (Alternative 5 prohibits the least, Alternative 3 prohibits 

the most). Cross country travel prohibitions would likely reduce the potential for sedimentation and 

alteration of streamside vegetation, and therefore benefit FYLF habitat.
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458 – Tahoe National Forest

Table 3.03-135. RCA miles and Stream Crossings Prohibited to Cross Country Travel

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Road miles closed from previous NEPA decisions, pending 

implementation

8.0 8.0 8.0 8.0 8.0 8.0 8.0

Crossings closed from previous NEPA decisions, pending 

implementation

19 19 19 19 19 19 19

RCA Miles prohibited to motorized public use with the 

prohibition of cross country travel (positive impact) 

0 68.1 71.2 69.1 57.0 65.8 69.9

Crossings prohibited to cross country travel 0 218 228 220 186 214 224

Total miles of cross country travel prohibited to 

motorized use

8.0 76.1 79.2 77.1 65.0 73.8 77.9

Total crossings prohibited to motorized use 19 237 247 239 205 233 243

NFTS Additions and Establishment of “Open Areas” – Motorized Stream Crossings and RCA Miles

Number of Native Surfaced, Motorized Stream Crossing Additions within FYLF 7th Field 

Watersheds. The number of native surfaced, motorized stream crossings, proposed for addition to the 

NFTS, are assessed for the alternatives, and provides a useful way to compare potential changes in 

sediment delivery within FYLF HUC7 watersheds. Alternative 1 poses the greatest risk of increased 

sedimentation where 228 motorized stream crossings are associated with the continuance of cross country 

travel on existing unauthorized routes (Table 3.03-136). The action alternatives all would result in 

reducing the number of crossings potentially contributing to sedimentation within FYLF HUC7 

watersheds. In decreasing order, Alternatives 5, 2, 6, 4, and 7 would result in the addition of 42 to 4 native 

surfaced, motorized route crossings. Alternative 3 does not add motorized route crossings to the NFTS, 

and therefore sedimentation or streamside vegetation would not be affected within any FYLF HUC7 

watersheds.

Table 3.03-136. Foothill Yellow-legged Frog 7th Field Watersheds - Number of Native Surfaced, Stream 

Crossings Associated with Motorized Route Additions

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Motorized Stream crossings associated with proposed 

motorized route additions (negative impact)

228 10 0 8 42 14 4

*Alternative 1 includes motorized stream crossings that would remain with the continuance of cross country travel on existing 

unauthorized routes, while all the action alternatives include motorized crossing additions.

Additions to the NFTS within FYLF 7th Field Watersheds. The miles of proposed motorized route 

additions to the NFTS within RCAs were assessed for the alternatives, and provide additional information 

to assess the potential for off-site sediment delivery into FYLF habitats at the HUC7 level. Alternative 1 

poses the greatest risk to increased sedimentation potential from 71.3 RCA miles of existing unauthorized 

motorized routes that would remain due to continued cross country travel (Table 3.03-137). Similar to 

stream crossing numbers, Alternatives 2, 4, 5, 6, and 7 would add between 1.3 and 14.2 RCA miles 

(Alternative 5 adds the most, Alternative 7 adds the least) of motorized routes. Alternative 3 does not add 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 459

motorized routes to the NFTS, and therefore changes to sedimentation or streamside vegetation would not 

occur within any FYLF HUC7 watershed.

Table 3.03-137. RCA Miles of Proposed Route Additions within FYLF HUC7 Watersheds

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Miles of proposed motorized route additions within RCAs* 

(negative impact)

71.3 3.1 0 2.2 14.2 5.4 1.3

*Alternative 1 includes existing unauthorized routes, while all the action alternatives include motorized route additions.

Establishment of “Open Areas” Alternative 2 would establish 60 acres of motorized open area at 

Greenhorn Creek where FYLF would potentially be adversely affected through increased erosion and 

sedimentation. In addition, FYLF could be directly affected from vehicle related mortality, since FYLF 

are known to occur within Greenhorn Creek. None of the other alternatives would propose establishment

of an open area at Greenhorn Creek, and therefore, FYLF would not be affected. Continued cross country 

travel would continue at Greenhorn Creek, and could adversely affect FYLF in the long-term.

Open Area establishments at Boca, Stampede, and Prosser reservoirs would not affect FYLF, since 

these reservoirs are outside the known geographic range of FYLF.

Changes to the NFTS

Change in Class of Vehicles. For each of the alternatives, Table 3.03-138 displays the effects of proposed 

changes in class of vehicles and the associated maintenance changes that have potential to increase the 

risk of delivering sedimentation and erosion to FYLF HUC7 watersheds. Alternatives 2, 5, and 6 result in 

the change in road maintenance levels resulting in changes from smooth surfaced roads to rough surfaced 

roads are likely to occur in the future with reduced maintenance. This change in road surface type has a 

higher potential to result in increased sedimentation to FYLF habitat affected by 1-2 crossings and from 

0.3-0.6 RCA miles motorized routes.

Table 3.03-138. Foothill Yellow Legged Frog – Effects from Change in Class of Vehicles 

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Number of Native Surfaced Crossings as a result 

changed maintenance standards

0 2 0 0 2 1 0

RCA Miles of changed maintenance standards from 

smooth surfaced to rough or native surfaced 

0 0.6 0 0 0.6 0.3 0

Reopened ML 1 Roads. Alternative 5 proposes to reopen numerous closed ML1 roads (Cal Ida 

Network). A few of the ML 1 roads have the potential to directly and indirectly affect FYLF sites within 

the Cherokee Creek and Fiddle Creek HUC7 watersheds. None of the other action alternatives would 

affect FYLF habitat.

Cherokee Creek HUC7. ML1 road #N39-7, intersects Young’s Ravine, and therefore reopening 

N39-7 would potentially directly and indirectly affect FYLF within Young’s Ravine, an intermittent 
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

460 – Tahoe National Forest

stream. Reopening other ML1 roads within the watershed may contribute to sediment, but would likely 

have a lesser direct and indirect impact to the known FYLF site in Young’s Ravine.

Fiddle Creek HUC 7. Reopening ML1 roads on the north side of Fiddle Creek has a small potential 

to impact the FYLF site in Fiddle Creek from ML1 roads that cross tributaries to Fiddle Creek (e.g., N25-

2, N25-2-1, N25-4-2, N25-4-2).

Site-specific Physical Impacts and Disturbance to Known Foothill Yellow-Legged Frog 

Locations. On the Tahoe NF, FYLF locations occur within forty-two 7th field watersheds. Table 3.03-139

displays the FYLF 7th field watersheds (HUC7) where motorized route additions are located and shows 

the relationship to known FYLF locations. Potential site-specific adverse and beneficial impacts at the 

HUC7 watershed scale are described.

Table 3.03-139. Direct and indirect effects of proposed motorized route additions and prohibition of cross 

country travel in relation to known FYLF locations by 7th field watershed

Watershed 

Name

Motorized 

Additions/Route ID

Reopened ML1 Road 

ID

Direct and Indirect 

Impacts of motorized 

additions and 

reopening ML 1 roads

Prohibition of Cross 

Country Travel

Bullards Bar 

ReservoirBridger Creek

D_Y-125_a (Alt 2,5,6) None Low risk that D_Y-125_a 

would impact FYLF 

habitat.

Proposed action 

alternatives prohibit cross 

country travel on 3 of 8 

intermittent/perennial NFS 

crossings.

Cherokee 

Creek

YRN-008 (Alt 2, 5, 6); 491-

3-1_p (Alt 5,6), 491-3-2_p 

(Alt 5,6); N39-6 (Alt 5), 

D_35_a-b (Alt 2,4,5,6); 

D_491-6_a-b (Alt 2,4,5,6).

0025-009, 0491-003, 25-9-

3_p, 25-9_p, 35-3_p, 35-4-

1_p, 35-4_p, 39-9_p, 491-

3_p (Alt 5 & 6); H39-12, 

N25-1-1, N25-3, N25-5, 

N25-6-1, N25-7, N25-9-1, 

N25-9-2, N35-1, N35-2, 

N35-3-1, N35-3-2, N35-6, 

N35-7, N39-4, N39-5, 

N39-5-1, N39-5-2, N39-7, 

N39-8-1, N491-1, N491-3-

1, N55-2 (Alt 5).

YRN-008 near the FYLF 

site and may impact FYLF.

D_35_a-b and D_491-6_ab, not connected and not 

likely to impact FYLF.

Alt 5 may have a 

cumulative effect to 

Cherokee Ck. HUC 7 

watershed due to the 

reopening of numerous ML 

1 roads. Some of the ML 1 

roads proposed for 

reopening are within the 

RCA of FYLF habitat and 

may directly and indirectly 

affect FYLF.

Proposed action 

alternatives prohibit cross 

country travel on up to 18 

of 25 intermittent/perennial 

NFS crossings.

Fall Creek D_14_b,d (Alt 2,4,5,6); 

D_14_e,f,h (Alt 6); D_17-6 

(Alt 6); D_17_b,c,e (Alt 6); 

D_18-14_c,d (Alt 2,4,5,6); 

D_18-14_e,f (Alt 6); 

D_18_a (Alt 2,4,5,6).

None Three short routes to 

dispersed recreation, low 

risk to FYLF site in 

mainstem of So. Yuba Rv. 

These routes are along 

Fall Creek >2 mi north of 

FYLF site. 3 routes to 

dispersed sites are not 

connected and would not 

affect FYLF.

Proposed action 

alternatives prohibit cross 

country travel on up to 4 of 

12 existing 

intermittent/perennial NFS 

crossings.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 461

Watershed 

Name

Motorized 

Additions/Route ID

Reopened ML1 Road 

ID

Direct and Indirect 

Impacts of motorized 

additions and 

reopening ML 1 roads

Prohibition of Cross 

Country Travel

Fiddle Creek N25-4-10, N27 (Alt 5); 

D_25-4_a,b,c,d (Alt 6).

0025-009, 25-9_p (Alt 5,6); 

N25-2, N25-2-1, N25-2-3, 

N25-4-2, N25-4-2-2, N25-

4-3, N25-4-4, N25-4-4-1, 

N25-4-6, N25-5, N25-8-1-

1, N25-8-2, N25-8-4, N25-

8-6. N25-8-8, N25-8-9, 

N25-8-10, N27-1, N27-2, 

N27-3, N27-4, N35-1, 

N55-1 (Alt 5).

FYLF site in lower portion 

of HUC7, N25-4-10; 

N27.and D_25-4_a,b,c,d in 

upper HUC7 do not impact 

FYLF.

Reopening over 20 miles 

of ML 1 roads on the north 

side of Fiddle Ck has a 

small potential to impact 

the FYLF site in Fiddle Ck.

Proposed action 

alternatives prohibit cross 

country travel on up to 23 

of 36 existing 

intermittent/perennial NFS 

crossings.

Fulda Creek None None One FYLF site not 

affected.

All action alternatives 

prohibit cross country 

travel on 2 of 8 existing 

intermittent/perennial NFS 

crossings.

Goodyears 

Creek

H25-18, N27-6-2 (Alt 5). N25-18-1, N25-19-1, N27-

9, N27-10 (Alt 5).

Proposed Alt 5 proposed 

routes above Snow Creek 

have small potential to 

affect FYLF sites in 

Goodyear’s Creek and 

North Yuba River. 

Proposed action 

alternatives prohibit cross 

country travel onup to 8 of 

20 existing 

intermittent/perennial NFS 

crossings.

Greenhorn 

Creek-South 

Fork 

Greenhorn 

Creek

Greenhorn Creek “Open 

Area” (Alt 2)

None Greenhorn “Open Area” 

could impact FYLF sites in 

Greenhorn Creek.

Proposed action 

alternatives prohibit cross 

country travel on up to 14 

of 21 existing 

intermittent/perennial NFS 

crossings.

Grizzly Creek None H613-8 (Alt 5). H613-8 on ridge, crosses 

upper end of intermittant 

trib. to Grizzly Ck, would 

not affect FYLF sites in 

Grizzly Creek.

All action alternatives 

prohibit cross country 

travel on 6 of 11 existing 

intermittent/perennial NFS 

crossings.

Headwaters 

Oregon Creek

D_S-300_a,b, D_S-304_a 

(Alt 2,4,5,6). 

None Two short routes to 

dispersed recreation areas 

are on opposite side of 

ridge from FYLF sites, 

FYLF sites would not be 

affected. A third route to 

dispersed recreation would 

have no to low potential 3-

4 miles away.

Proposed action 

alternatives prohibit cross 

country travel on 8 of 10 

existing 

intermittent/perennial NFS 

crossings.

Humbug 

Canyon

ARM-7, ARM-5 (Alt 2, 4, 5, 

6, 7); D-66, D_66-18 (Alt 

2,4,5,6). 

None ARM-5, ARM-7 & D-66, 

D_66-18 not likely to 

impact FYLF, ARM-5 up 

on ridge w/ no connection 

to frog site.

Proposed action 

alternative prohibit cross 

country travel on 2 of 13 

existing 

intermittent/perennial NFS 

crossings, that were 

closed from previous 

NEPA decisions.

Indian Creek None None No effect to one FYLF site. None

Lower Downie 

River

D_10E02_a (Alt 2,5,6). YRN-509 (Alt 2,5,6). D_10E02_a has low 

potential to affect FYLF 

site. YRN-509 is not likely 

to impact FYLF.

All action alternatives 

prohibit cross country 

travel on 1 of 19 existing 

intermittent/perennial NFS 

crossings.

Lower Kanaka 

Creek

None None No effects to multiple 

FYLF sites

All action alternatives 

prohibit cross country 

travel on 9 of 24 existing 

intermittent/perennial NFS 

crossings.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

462 – Tahoe National Forest

Watershed 

Name

Motorized 

Additions/Route ID

Reopened ML1 Road 

ID

Direct and Indirect 

Impacts of motorized 

additions and 

reopening ML 1 roads

Prohibition of Cross 

Country Travel

Lower Middle 

Yuba River

None None One FYLF site, not 

affected.

All action alternatives 

prohibit cross country 

travel on 2 of 6 existing 

intermittent/perennial NFS 

crossings.

Lower North 

Shirttail 

Canyon

ARM-3r (Alt 2,4,5,6,7). None 89% FS; RCA ws-1 mi 7.3 

(6.7 FS); ARM-3 & ARM3a are above FYLF sites 

are not likely impact FYLF; 

all action alternatives 

prohibits cross country 

travel on routes nearest to 

FYLF streams.

All action alternatives 

prohibit cross country 

travel on 13 of 26 existing 

intermittent/perennial NFS 

crossings.

Lower Oregon 

Creek

None None Multiple FYLF sites. No 

effect – no additions or 

reopened ML 1 roads in 

HUC7.

All action alternatives 

prohibit cross country 

travel on 1of 15 existing 

intermittent/perennial NFS 

crossings.

Lower 

Poorman 

Creek

None None None All action alternatives 

prohibit cross country 

travel on 4 of 34 existing 

intermittent/perennial NFS 

crossings.

Middle Yuba 

River-Indian 

Creek

None None Multiple FYLF sites, no 

proposals, therefore no 

impacts.

All action alternatives 

prohibit cross country 

travel on 3 of 26 existing 

intermittent/perennial NFS 

crossings.

Middle Yuba 

River-Moores 

Flat Creek

YRM-M4 (Alt 2,5,6,7), 

D_10E18_a (Alt 2,5,6). 

None Multiple FYLF sites. YRMM4 is isolated and not 

likely to impact FYLF 

D_10E18_a, short spur to 

dispersed recreation site is 

on the mainstem of the 

Middle Yuba, not likely to 

affect FYLF sites in tribs.

All action alternatives 

prohibit cross country 

travel on 7of 26 existing 

intermittent/perennial NFS 

crossings.

Middle Yuba 

River-National 

Gulch

None None None All action alternatives 

prohibit cross country 

travel on 5 of 24 existing 

intermittent/perennial NFS 

crossings.

Middle Yuba 

RiverStudhorse 

Canyon

None H613-8 (Alt 5). Multiple FYLF sites. 

Reopening ML 1 road 

H613-8 would not impact 

FYLF sites in Grizzly 

Creek.

All action alternatives 

prohibit cross country 

travel on 2 of 7 existing 

intermittent/perennial NFS 

crossings.

North Fork 

American 

River-Giant 

Gap Gulch

None None No impact to single FYLF 

site

All action alternatives 

prohibit cross country 

travel on 0 of 13 existing 

intermittent/perennial NFS 

crossings.

North Fork 

Middle Fork 

American 

River -El 

Dorado 

Canyon

None None Multiple FYLF sites. No 

route additions or 

reopened ML 1 proposed.

All action alternatives 

prohibit cross country 

travel on 2 of 9 existing 

intermittnet/perennial NFS 

crossings.
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Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 463

Watershed 

Name

Motorized 

Additions/Route ID

Reopened ML1 Road 

ID

Direct and Indirect 

Impacts of motorized 

additions and 

reopening ML 1 roads

Prohibition of Cross 

Country Travel

North Yuba 

River-Humbug 

Creek

D_34_a,b,c (Alt 2,4,5,6), 

N27-6-2 (Alt 5).

H293-19, N27-5 (Alt 5). Multiple FYLF sites in 

Humbug Creek

Proposed Alt 5 route 

H293-19 in upper parts of 

watershed above FYLF 

sites, very slight potential 

of impact FYLF.

Proposed action 

alternatives prohibit cross 

country travel up to 4 of 15 

existing 

intermittent/perennial NFS 

crossings.

North Yuba 

River-Indian 

Creek

YRM-M3 (Alt 2, 5,6), H34-

8-3 (Alt 5), D_49-27_a (Alt 

2,5,6).

H34-4, N-39-5, N39-5-3, 

N39-5-4 (Alt 5).

Multiple FYLF sites. YRNM3, H34-8-3 and several 

Alt 5 proposed reopening 

of ML 1 roads (H34-4, N39-5, N39-5-3, N39-5-4) 

are outside of the RCA 

and would not likely deliver 

sediment to FYLF sites in 

Indian Ck.

D_49-27_a, short spur 

accesses dispersed 

recreation is adjacent to 

Indian Ck and may impact 

FYLF habitat.

Proposed action 

alternatives prohibit cross

country travel on 5 (Alts 

3,4,6,7) or adds 8 (Alts 

2,5) to 19 existing 

intermittent/perennial NFS 

crossings.

North Yuba 

River-New 

York Ravine

None None None All action alternatives 

prohibit cross country 

travel on 3 of 20 existing 

intermittent/perennial NFS 

crossings.

North Yuba 

River-Slug 

Canyon

None YRN-509 (Alt 2,5,6). YRN-509 on ridge above 

not connected to FYLF 

site, not likely to directly or 

indirectly affect FYLF site

All action alternatives 

prohibit cross country 

travel on 5 of 12 existing 

intermittent/perennial NFS 

crossings.

Oregon CreekMarion Creek

None None None All action alternatives 

prohibit cross country 

travel on 4 of 13 existing 

intermittent/perennial NFS 

crossings.

Oregon CreekMiller CreekD_S-295_a,b,c (Alt 

2,4,5,6), H293-4-18 (Alt 5).

None H293-4-18 not connected 

to stream, not likely to 

impact FYLF. Three short 

spurs to dispersed 

recreation sites have low 

potential to impact FYLF in 

Oregon Creek. Routes are 

stable and not eroding.

Proposed action 

alternatives prohibit cross 

country travel on 9 (Alts 

2,4,5,6) to 10 (Alts 3,7) of 

31 existing 

intermittent/perennial NFS 

crossings.

Rock CreekNorth Yuba 

River

D_S300_b (Alt 2,4,5,6). None D_S300_b not connected 

to stream, not likely to 

impact FYLF

All action alternatives 

prohibit cross country 

travel on 4 of 11 existing 

intermittent/perennial NFS 

crossings.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

464 – Tahoe National Forest

Watershed 

Name

Motorized 

Additions/Route ID

Reopened ML1 Road 

ID

Direct and Indirect 

Impacts of motorized 

additions and 

reopening ML 1 roads

Prohibition of Cross 

Country Travel

South Yuba 

RiverDiamond 

Creek

YRS-SF4 (Alt 2, 5, 6);

H29-11, D_18-14_a,b (Alt 

5); D_20-16_a (Alt 

2,4,5,6); D_738-

4_a,b,c,d,e,f,g (Alt 2,5,6).

H20-16-2-7 H29-11 is short route that 

is not likely to affect FYLF 

site in Diamond Ck. 

D_18-14_a,b; D_20-16_a; 

D_738-4_a,b,c,d,e,f,g has 

potential to impact So. 

Yuba River sites.

YRS-SF4 may affect FYLF 

downstream near 

Diamond Ck. may be 

affected by sediment into 

spring near the north end 

of route YRS-SF4.

H20-16-2-7 is a ML 1 road 

proposed for reopening in 

Alt 5, not connected, 

outside of RCA, and would 

not affect FYLF in 

Diamond Ck.

Proposed action 

alternatives prohibit cross 

country travel on up to 2 of 

15 existing 

intermittent/perennial NFS 

crossings.

South Yuba 

RiverJefferson 

Creek

D_CA-20_a (Alt 6). H20-8-5 (Alt 5). Two FYLF sites. Road 

H20-8-5 ties into NFTS 

road, and FYLF site south 

of reopened ML 1 road is 

not connected, no impact 

to frog.

D_CA-20_a not connected 

and would not affect FYLF 

sites.

All action alternatives 

prohibit cross country 

travel on 2 of 13 existing 

intermittent/perennial NFS 

crossings.

South Yuba 

River-Logan 

Canyon

None None None All action alternatives 

prohibit cross country 

travel on 4 of 13 existing 

intermittent/perennial NFS 

crossings.

South Yuba 

River-New 

York Canyon

D_20-3-5_a, D_20-3_a 

(Alt 6).

H20-3-5-2-3, H20-3-5-2-4 

(Alt 5).

D_20-3-5_a, D_20-3_a; 

H20-3-5-2-3, and H20-3-5-

2-4, not connected to 

FYLF site.

All action alternatives 

prohibit cross country 

travel on 2 of 4 existing 

intermittent/perennial NFS 

crossings.

South Yuba 

RiverScotchman 

Creek

YRS-066 (Alt 2,5,6), YRSSF6 (Alt 2, 4, 5, 6, 7), 

YRS-SF6b (Alt 2,4,5,7).

None Multiple FYLF sites. YRS066, YRS-SF6, and YRSSF6b not likely to affect 

FYLF sites, not connected.

Proposed action 

alternatives prohibit cross 

country travel on up to 8 of 

11 existing 

intermittent/perennial NFS 

crossings.

Upper North 

Shirttail 

Canyon

ARM-2 (Alt 2,5,6,7), ARM5 (Alt 2,4,5,6,7).

None Multiple FYLF sites. ARM2 some potential to impact 

FYLF site, ARM-5 on ridge 

- no connection and would 

not impact to FYLF site 

All action alternatives 

prohibit cross country 

travel on 14 of 30 existing 

intermittent/perennial NFS 

crossings.

Upper 

Poorman 

Creek

D_843-9_a (Alt 2,5,6). None Multiple FYLF sites in 

Poorman Ck, not likely to 

be affected by short spur 

to dispersed recreation ~ 

1⁄2 mile south of Poorman 

Ck.. 

Proposed action 

alternatives prohibit cross 

country travel on up to 4 of 

29 existing 

intermittent/perennial NFS 

crossings.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 465

Watershed 

Name

Motorized 

Additions/Route ID

Reopened ML1 Road 

ID

Direct and Indirect 

Impacts of motorized 

additions and 

reopening ML 1 roads

Prohibition of Cross 

Country Travel

Upper Shirttail 

Canyon

ARM-3r (Alt 2,4,5,6,7). None Multiple FYLF sites. ARM3r is not proximal to sites 

and will not impact FYLF. 

All action alts prohibits 

cross country travel on 

unauthorized routes 

nearest to FYLF sites

All action alternatives 

prohibit motorized cross 

country travel on 5 of 25 

intermittent/perennial NFS 

crossings.

Upper 

Steephollow 

Creek

YRS-SF5, YRS-S6 (Alt 

2,4,5,6,7,); YRS-B10 (Alt 

2,5); D_18_6; D_20-17, 

D_20-17-1, D_29-5, D-32, 

D_CA-20_b, D_NEV-329 

(Alt 6).

None Most of YRS-S5, part of 

YRS-F6 and YRS-B10 

above FYLF site - not 

likely to affect FYLF, YRSS5 could put sediment into 

main channel where FYLF 

site is located.

4 dispersed recreation 

routes not connected and 

would not affect FYLF site 

in Steephollow Ck.

Proposed action 

alternatives prohibit 

motorized cross country 

travel on up to 5 of 16 

existing 

intermittent/perennial NFS 

crossings.

Willow Creek H293 (Alt 5); D-Y122_a,b,c (Alt 2,4,5,6).None H293 in southeastern 

portion of watershed has 

low risk of affecting FYLF 

sites.

D-Y-122_a,b,c, on Brandy 

Ck is upstream from FYLF 

in Brandy and Willow 

creeks, may affect FYLF

Proposed action 

alternatives prohibit 

motorized cross country 

travel on up to 19 of 28 

existing 

intermittent/perennial NFS 

crossings.

Wolf Creek None None None Proposed action 

alternatives prohibit 

motorized cross country 

travel on 5 

intermittent/perennial NFS 

crossings.

Route Density within Riparian Conservation Areas (RCAs): Route density within Riparian 

Conservation Areas (RCAs) for all native surfaced motorized routes within 7th field watersheds with 

known observations of foothill yellow-legged frogs was determined for the proposed alternatives. 

Alternative 1 poses the greatest risk of high route densities within Riparian Conservation Areas (RCAs) 

(Table 3.03-140, Figure 3.03-13). 

Under Alternative 1, 26% (11 of 42) of the HUC7 watersheds with FYLF detections are within route 

density categories of highest, 35% (9 of 42) are in the moderately high, 36% (15 of 42) are in moderately 

low, and 17% (70 of 42) are in the lowest density category. The remaining alternatives would reduce the 

RCA route densities for motorized route density (native surfaced routes) compared to Alternative 1. 

Alternative 5 would reduce the least, followed by Alternatives 2, 6, 7, 4, and 3, in descending order of 

high risk route densities within the RCAs that would potentially capture sediment affecting FYLF 

habitats.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

466 – Tahoe National Forest

Native Surface, Motorized RCA Native, Surface Route Density 

HUC7s with Suitable Foothill Yellow-Legged Frog Habitat

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Alternative

Percent of Watersheds with Suitable FYLF Habitat

highest (8.9 - 27.3)

moderately high (6.3 - 8.8)

moderately low (4.3 - 6.2)

low est (0.2 - 4.2)

Table 3.03-140. Number and proportion of Foothill Yellow-legged Frog 7th Field Watersheds within Route 

Density Categories of Highest, Moderately High, Moderately Low, and Lowest or Forty two 7th Field 

Watersheds (HUC7s) with Foothill Yellow-legged Frog Observations

Alternatives Highest

(8.9 - 27.3 mi/mi2

)

Moderately High

(6.3 – 8.8 mi/mi2)

Moderately Low

(4.3 – 6.2 mi/mi2)

Lowest

(0.2 – 4.2 mi/mi2)

Alt 1 11 (26%) 9 (21%) 15 (36%) 7 (17%)

Alt 2 5 (12%) 8 (19%) 9 (21%) 20 (48%)

Alt 3 3 (7%) 7 (17%) 9 (21%) 23 (55%)

Alt 4 4 (10%) 6 (14%) 9 (21%) 23 (55%)

Alt 5 7 (17%) 7 (17%) 10 (24%) 18 (43%)

Alt 6 4 (10%) 7 (17%) 10 (24%) 21 (50%)

Alt 7 4 (10%) 6 (14%) 9 (21%) 23 (55%)

Figure 3.03-13. Number of HUC7 Watersheds with Foothill Yellow-legged Frogs by Route Density Category 

for Motorized Route Density (Native Surfaced) with Riparian Conservation Areas

Stream Crossing Density within Riparian Conservation Areas (RCAs): RCA stream crossing 

density was assessed by route density categories of highest (8.9 - 27.3 crossings/mi2

), moderately high 

(6.3 - 8.8 crossings/ mi2), moderately low (4.3 - 6.2 crossings/ mi2), and lowest (0.2 - 4.2 crossings/ mi2) 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 467

within 7th field watersheds (HUC7s) with known foothill yellow-legged frog observations (Table 3.03-

141, Figure 3.03-14). 

Alternative 1 poses the greatest direct impacts to foothill yellow-legged frogs (FYLF) from stream 

crossing densities where frogs may be disturbed and/or killed; and FYLF aquatic habitat conditions can 

be impacted from bank alteration and sediment input associated with motorized route crossings. Under 

Alternative 1, 62% (26 of 42) of HUC7 watersheds with known FYLF detections are within the highest, 

14% (6 of 42) in the moderately high, 12% (5 of 42) in moderately low, and 12% (5 of 42) are in the 

lowest crossing density categories.

All the alternatives would significantly reduce crossing densities where Alternative 5 would reduce 

the least, followed by Alternatives 2, 6, 4, 7, and 3, in decreasing order of crossing densities. 

Table 3.03-141. Number and Proportion of Foothill Yellow-legged Frog 7th Field Watersheds within Route 

Crossing Density Categories of Highest, Moderately High, Moderately Low, and Lowest or Forty one HUC7s 

with Foothill Yellow-legged Frog Observations

Alternatives Highest

(8.9 -27.3 crossings/mi2

)

Moderately High

(6.3-8.8 crossings/mi2)

Moderately Low

(4.3- 6.2 crossings/mi2)

Lowest

(0.2-4.2 crossings/mi2)

Alt 1 26 (62%) 6 (14%) 5 (12%) 5 (12%)

Alt 2 16 (38%) 12 (28%) 5 (12%) 9 (21%)

Alt 3 13 (31%) 11 (26%) 9 (21%) 9 (21%)

Alt 4 13 (31%) 12 (28%) 8 (19%) 9 (21%)

Alt 5 17 (40%) 13 (31%) 5 (12%) 8 (19%)

Alt 6 13 (31%) 13 (31%) 8 (19%) 8 (19%)

Alt 7 13 (31%) 11 (26%) 9 (21%) 9 (21%)
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

468 – Tahoe National Forest

Native Surface, Motorized Stream Crossing Density 

HUC7s with Suitable Foothill Yellow-Legged Frog Habitat

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Alternatives

Percent of Watersheds with Suitable FYLF Habitat

highest (8.9 - 27.3)

moderately high (6.3 - 8.8)

moderately low (4.3 - 6.2)

low est (0.2 - 4.2)

Figure 3.03-14. Number of HUC7 Watersheds with Foothill Yellow-legged Frogs by Route Density Category 

for Motorized Stream Crossing Density (Native Surfaced) with Riparian Conservation Areas

Cumulative Effects

Cumulative Effects Boundary in Space and Time

The geographic boundary for assessing cumulative effects to the Foothill yellow-legged frog (FYLF) is 

the westside of the Tahoe NF below 6,000 feet within slow-moving streams, since this is within habitat 

that is considered suitable on the Tahoe NF. This geographic boundary is sufficiently large to encompass 

historic and potential FYLF habitat on the Tahoe NF. Any larger boundary could dilute the effects of past, 

present, and future cumulative impacts to this species. The timeframe for assessing cumulative impacts in 

the past includes activities that occurred within the last 50 to 100 years. Reasonably foreseeable future 

impacts expand out to approximately 25 years into the future.

Cumulative Effects of Past, Present, and Reasonably Foreseeable Actions

Foothill yellow-legged frogs were once common in streams of the Sierra Nevada, and are now 

increasingly rare. Foothill yellow-legged frogs have been extirpated from at least two thirds of their 

historic localities over their entire Sierran range (Jennings 1996, Lind 2005). Lind (2005) estimated that 

FYLF populations (prior to 1980) have disappeared from approximately 51% of their historic range. 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 469

Many past cumulative impacts have contributed to the decline in FYLF numbers and distribution. The 

reduction in foothill yellow-legged frog distribution and population numbers has largely been attributed to 

the stocking of non-native fish species. FYLF previously extended to Sacramento Valley floor. In 

addition, the introduction of bullfrogs has likely contributed to the decline in the FYLF as well from 

competition and predation by the bullfrog. Predation on the FYLF from other species includes birds, 

mammals, and snakes, however, the population effects on the FYLF from predation of these species is 

unknown.

Historic livestock grazing likely had a significant cumulative impact to FYLF and their habitat. 

Historic livestock grazing evidence indicates that heavy livestock use in the Sierra Nevada led to riparian 

habitat degradation across much of the Sierra Nevada. Livestock trampling has the potential to directly 

kill all life stages of FYLF. The greatest potential of mortality risk from livestock trampling is expected to 

occur when adult FYLF aggregate and lay egg masses in the early season, and during metamorphosis, 

when juveniles are metamorphosing along aquatic margins. Current standards and guidelines in the Sierra 

Nevada Forest Plan Amendment were implemented to reduce the risk of trampling by livestock (USDA 

2001). Known of FYLF habitat sites on the Forest currently overlap with 5 active livestock allotments 

(American Hill, Middle Yuba, Oregon Creek, Sugar Pine and Willow Creek). Suitable foothill yellowlegged frog habitat (no known detections) overlaps with an additional 6 allotments.

Urbanization within private lands makes up the largest fraction (about 50 percent) of historic FYLF 

range in the Sierra Nevada. Only about 25 percent of historic foothill yellow-legged frog range occurs on 

National Forest lands, they are not documented from Wilderness Areas or National Park lands in the 

Sierra Nevada, where roads are few. The remaining 25 percent of foothill yellow-legged frog habitat lies 

on state lands, other federal lands (e.g., Bureau of Land Management [BLM], Bureau of Reclamation 

[BOR]), or tribal lands.

Historic vegetation management and fuels reduction projects have likely contributed to past and 

present cumulative effects, especially if projects occurred adjacent to FYLF aquatic habitats. Ground 

disturbing activities including timber harvest and fuels treatment projects (burning and mastication 

projects) potentially caused direct mortality to this species which may have affected the abundance of the 

species on the Tahoe NF. In general, current vegetation and fuels projects are designed to reduce potential 

impact on FYLF habitats, and therefore, minimize disturbance to the species. However, as FYLF migrate 

between breeding sites, and between breeding sites and overwintering sites, there is some potential for 

direct impacts from being crushed or burned from vegetation and fuels projects. In general the magnitude 

of this happening across the range of the FYLF frog habitats on the Tahoe NF should be limited given the 

timing of FYLF migration which is in the spring.

Hydroelectric projects have likely contributed to the decline of FYLF across its range in the Sierra 

Nevada and on the Tahoe NF. FYLF egg masses are unable to service regulated pulsed flow events. 

Under Alternative 1, HUC7 watersheds occupied by FYLF would have the highest RCA route 

densities and the highest route crossing densities as a result of continued cross country travel, including 

on routes unauthorized to motorized public use within Riparian Conservation Areas. Direct and indirect 

impacts of these motorized routes in Alternative 1 would pose considerable cumulative impacts to known 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

470 – Tahoe National Forest

FYLF sites where approximately 40% of HUC7 watersheds with FYLF observations have high to 

moderately high RCA route densities that may contribute to habitat degradation from off-site 

sedimentation. In addition, under Alternative 1, 56% of HUC7 watersheds with known FYLF detections 

are within the highest or moderately high route density categories which have the potential to degrade 

stream condition by altering streambank vegetation and stream hydrology. Under Alternative 1, motorized 

route proliferation would likely continue and increase at an accelerated rate in the future, potentially 

increasing sediment delivery and alteration of streambank vegetation and hydrologic condition which may 

affect the abundance and distribution on the Tahoe NF. Declining population trends of this species could 

be affected by Alternative 1.

Alternative 5 also adds to existing cumulative impacts to the FYLF, though impacts are considerably 

less than Alternative 1 as a result of the closure of a significant number of miles of motorized routes 

within RCAs and reduction in the number of route crossings. Under Alternative 5, RCA route densities 

and route crossing densities are the second highest after Alternative 1, where 32% of the HUC7 

watersheds with are within the highest and moderately high RCA route density categories; and 44% of 

HUC7 watersheds are within the highest to moderately high RCA route density categories. Site-specific 

impacts from proposed route additions in Alternative 5, directly or indirectly affects FYLF within 20 

HUC7 watersheds where proposed route additions have the potential to contribute to FYLF habitat 

degradation.

Alternatives 2 and 6 are similar in their cumulative impacts to FYLF where known FYLF sites may 

be directly or indirectly affected within 15-17% FYLF HUC7 watersheds by proposed motorized route 

additions. The remaining action alternatives are similar in their cumulative effects to the FYLF where a 

slight potential for cumulative impacts from direct and indirect impacts to known FYLF sites have the 

potential to occur within 0% (Alternative 3) to 5% (Alternative 7) of FYLF HUC7 watersheds (n=41). 

FYLF sites are similarly affected by Alternatives 2 and 6, where 7 (17%) and 6 (15%) FYLF HUC7 

watersheds are affected by motorized route additions, respectively. Alternatives 2, 4, and 7 affect the least 

number of FYLF sites within 0 (0%), 1(2%), and 2 (5%) HUC7 watersheds respectively, where FYLF 

would most benefit from the prohibition of cross country travel, including on unauthorized routes. For all 

the action alternatives, future unmanaged cross country motorized travel would be prohibited, including 

on the majority of unauthorized routes, which would benefit FYLF in the long-term once these routes are 

rehabilitated through obliteration or other means.

Summary of Direct, Indirect, and Cumulative Effects of Proposed Actions

Table 3.03-142 summarizes the direct, indirect, and cumulative effects of native surfaced, motorized route 

crossings within FYLF HUC 7 watersheds, from existing motorized routes, motorized route additions, 

and routes unauthorized to motorized public travel from the proposed actions, including wet weather 

seasonal restrictions, changes in class of vehicles, prohibition of cross country travel. See Chapter 3.02,

Watershed Resources: Geology, Soil, Hydrology, for more detailed information and assumptions.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 471

Table 3.03-142. Foothill Yellow-legged Frog 7th Field Watersheds – Summary of Direct, Indirect, and Cumulative Effect of Proposed Actions as 

Measured by Native Surfaced, Motorized Crossings

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

RCA Acres Prohibited 0 34,092 34,092 34,092 34,092 34,092 34,092

Crossings Closed in 

previous NEPA decisions, 

pending implementation

19 19 19 19 19 19 19

RCA Miles Closed in 

previous NEPA decisions, 

pending implementation

8.0 8.0 8.0 8.0 8.0 8.0 8.0

Crossings Prohibited 0 218 228 220 186 214 224

RCA Miles Prohibited 0 68.1 71.2 69.1 57.0 65.8 69.9

Native Surfaced, Motorized Stream Crossings

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Existing 155 155 155 155 155 155 155

Crossing Additions 228 10 0 8 42 14 4

Change in Class of 

Vehicles Resulting in 

Smooth Surfaced to Native 

Surfaced Crossings

0 2 0 0 2 1 0

Reopened ML 1 Roads 0 0 0 0 0 0 0

Net Native Surfaced, 

Motorized Crossings

383 167 155 163 199 170 159
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

472 – Tahoe National Forest

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Wet Weather Seasonal Restrictions on all Native Surfaced Routes

Trend of Effect Negative Negative Negative Beneficial Beneficial Beneficial Negative

No additional wet 

weather 

restrictions

No additional wet 

weather 

restrictions

No additional wet 

weather 

restrictions

Wet Weather 

Restrictions 

would be 

implemented

Wet Weather 

Restrictions 

would be 

implemented

Wet Weather 

Restrictions 

would be 

implemented

No additional wet 

weather 

restrictions

Establishment of “Open 

Areas” at Greenhorn Creek

No Effect Negative No Effect No Effect No Effect No Effect No Effect

Amendments to the Forest 

Plan

No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Net Direct, Indirect, and 

Cumulative Effect of 

Proposed Actions

Adverse 

cumulative effects 

from motorized 

cross country 

travel continued 

on 34,092 RCA 

acres, including 

on 228 native 

surfaced, stream 

crossings 

unauthorized for 

motorized use.

Continued use on 

383 motorized 

crossings 

No additional 

protection to 

FYLF habitats 

from wet weather 

seasonal 

restrictions.

6th most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

34,092 RCA 

acres, including 

on 218 native 

surfaced, stream 

crossings.

167 crossings 

available for 

motorized use.

No additional 

protection to 

FYLF habitats 

from wet weather 

seasonal 

restrictions.

4th most beneficial 

alternative. 

Motorized cross 

country travel 

prohibited on 

34,092 RCA 

acres, including 

on 228 native 

surfaced, stream 

crossings 

155 crossings 

available for 

motorized use. 

No additional 

protection to 

FYLF habitats 

from wet weather 

seasonal 

restrictions.

Most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

34,092 RCA 

acres, including 

on 220 native 

surfaced, stream 

crossings

163 crossings 

available for 

motorized use. 

Reduced 

sedimentation risk 

to FYLF habitats 

from wet weather 

seasonal 

restrictions.

3rd most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

34,092 RCA 

acres, including 

on186 native 

surfaced, stream 

crossings

199 crossings 

available for 

motorized use.

Reduced 

sedimentation risk 

to FYLF habitats 

from wet weather 

seasonal 

restrictions.

2nd most 

beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

34,092 RCA 

acres, including

on214 native 

surfaced, stream 

crossings

170 crossings 

available for 

motorized use.

Reduced 

sedimentation risk 

to FYLF habitats 

from wet weather 

seasonal 

restrictions.

5th most beneficial 

alternative. 

Motorized cross 

country travel 

prohibited on 

34,092 RCA 

acres, including 

on 224 native 

surfaced, stream 

crossings

159 crossings 

available for 

motorized use.

No additional 

protection to 

FYLF habitats 

from wet weather 

seasonal 

restrictions.

*Alternative 1 includes existing native surfaced, crossings unauthorized to motorized use, while all the action alternatives include motorized route additions.

Table 3.03-143 summarizes the direct, indirect, and cumulative effects of native surfaced, motorized RCA route miles within FYLF HUC 7 

watersheds, from existing motorized routes and from the proposed actions: prohibition of cross country travel, motorized route additions to the 

NFTS, and changes to the NFTS. See Chapter 3.02, Watershed Resources: Geology, Soil, Hydrology, for more detailed information and 

assumptions.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 473

Table 3.03-143. Foothill Yellow-legged Frog 7th Field Watersheds – Summary of Direct, Indirect, and Cumulative Effect of Proposed Actions as 

Measured by RCA Motorized Route Miles

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres of FYLF RCA Cross 

Country Travel Prohibited

0 34,092 34,092 34,092 34,092 34,092 34,092

RCA Route Miles 

Prohibited to Cross 

Country Travel

0 68.1 71.2 69.1 57.0 65.8 69.9

RCA Miles Closed in 

Previous NEPA 

decisions, pending 

implementation

8.0 8.0 8.0 8.0 8.0 8.0 8.0

Native Surfaced, Motorized Routes

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Existing NFTS RCA Miles 52.7 52.7 52.7 52.7 52.7 52.7 52.7

RCA Miles of Additions* 71.3 3.1 0 2.2 14.2 5.4 1.3

Closed by Previous NEPA 

decisions, pending 

implementation (positive)

8.0 8.0 8.0 8.0 8.0 8.0 8.0

Change in Class of 

Vehicles Resulting in 

Changed Maintenance 

Level, Changed from 

Smooth Surfaced to 

Native Surfaced Route

0 0.6 0 0 0.6 0.3 0

Net NFTS Native 

Surfaced, Motorized RCA 

Miles

132.0 64.4 60.7 62.9 75.5 66.4 62.0
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

474 – Tahoe National Forest

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Wet Weather Seasonal Restrictions on all Native Surfaced Routes

Trend of Effect Negative Negative Negative Beneficial Beneficial Beneficial Negative

Proposed Wet Weather No additional wet 

weather 

restrictions

No additional wet 

weather 

restrictions

No additional wet 

weather 

restrictions

Wet Weather 

Restrictions 

would be 

implemented

Wet Weather 

Restrictions 

would be 

implemented

Wet Weather 

Restrictions 

would be 

implemented

No additional wet 

weather 

restrictions

Net Direct, Indirect, and 

Cumulative Effect of 

Proposed Actions

Cumulative 

adverse effects 

from continued 

motorized cross 

country travel on 

34,092 RCA 

acres, including 

on 71.3 RCA 

miles of 

unauthorized 

routes . 

Motorized use 

continues on 132 

RCA miles 

6th most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

34,092 RCA 

acres, including 

on 76.1 RCA 

miles of routes 

unauthorized for 

motorized use. 

NFTS motorized 

use available on 

64.4 RCA miles. 

4th most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

34,092 RCA 

acres, including 

on 79.2 RCA 

miles of routes 

unauthorized for 

motorized use. 

NFTS motorized 

use available on 

60.7 RCA miles. 

Most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

34,092 RCA 

acres, including 

on 77.1 RCA 

miles of routes 

unauthorized for

motorized use. 

NFTS motorized 

use available on 

62.9 RCA miles. 

Additional wet 

weather 

restrictions apply.

3rd most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

34,092 RCA 

acres, including 

on 65.0 RCA 

miles of 

unauthorized 

routes.

NFTS motorized 

use available on 

75.5 RCA miles.

Additional wet 

weather 

restrictions apply

2nd most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

34,092 RCA 

acres, including 

on 73.8 RCA 

miles of 

unauthorized 

routes.

NFTS motorized 

use available on 

66.4 RCA miles. 

Additional wet 

weather 

restrictions apply

5th most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

34,092 RCA 

acres, including 

on 77.9 RCA 

miles of 

unauthorized 

routes.

NFTS motorized 

use available on 

62.0 RCA miles.

*Alternative 1 includes existing native surfaced, unauthorized routes, while all the action alternatives include motorized route additions.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 475

Mountain Yellow-Legged Frog: Affected Environment

The mountain yellow-legged frog (MYLF) is listed as Sensitive on the Region 5 Forester’s Sensitive 

Species List (USDA Forest Service 1998). Mountain yellow-legged frogs occur in the Sierra Nevada from 

4,500 feet to over 12,000 feet elevation (Jennings and Hayes 1994). Previously the mountain yellowlegged frog in the Sierra Nevada was considered to be one species; Rana muscosa. Recent genetic studies 

indicate mountain yellow-legged frogs in the Sierra Nevada are comprised of two species: R. sierrae, with 

a distribution in the northern and central Sierra Nevada, and R. muscosa, with a distribution in the 

southern Sierra Nevada and southern California. The contact zone for these two newly recognized species 

is in the vicinity of Mather Pass and the Monarch Divide, Fresno County (Vredenburg et al. 2007).

Mountain yellow-legged frogs in the Sierra Nevada inhabit high mountain lakes, ponds, tarns, and 

streams, largely in areas that were glaciated (Zweifel 1955, In Lannoo 2005). Mountain yellow-legged 

frogs are seldom far from water, although they have been observed moving overland to disperse to other 

pond habitats. Typically, mountain yellow-legged frogs prefer well illuminated, sloping banks of meadow 

streams, riverbanks, isolated pools, and lake borders with vegetation that is continuous to the water’s edge 

(Martin 1992, Zeiner et al. 1988). Vredenburg et al. (2004) found that R. muscosa (sensu stricto) tended to 

use stillwater habitats more frequently than R. sierrae, but it is unclear whether is difference is the result 

of stillwater habitat being more frequent within the formers geographic range or an actual phylogenetic 

difference in habitat selection behavior.

The Tahoe National Forest database has records for mountain yellow-legged frogs in 79 locations. 

Most of these observations were of individual frogs. Only 49 of these sightings are considered recent 

(Since 1980). Mountain yellow-legged frogs have been observed in both stream and pond habitats on the 

forest. The largest populations observed in recent surveys (1993-2002) were those containing 5 adults 

(Lyon Bog, Rattlesnake Creek, and Poorman Creek). The species appears to have disappeared from a 

significant number of historic locations within the Tahoe National Forest and is in very low abundance 

where it still persists.

Mountain Yellow-Legged Frog: Environmental Consequences

Indicators used to Measure Effects

Cross Country Travel: The prohibition of cross country travel is analyzed for the alternatives to estimate 

the potential benefits and reduction in effects to MYLF 7th field watersheds from motorized cross country 

travel.

NFTS Additions and Establishment of “Open Areas” (MYLF 7th field watersheds): Measures or 

indicators of changes in sedimentation and water surface shade are assessed by analyzing the number of 

stream crossings additions associated with motorized route additions to the NFTS, and the miles of 

motorized route additions within Riparian Conservation Areas (RCAs) for MYLF 7th field watersheds. 

MYLF is not affected by the “Open Area” establishments, since no MYLF habitat occurs within or 

adjacent to proposed “Open Area” establishments at Greenhorn Creek or at Boca, Stampede, or Prosser

reservoirs.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

476 – Tahoe National Forest

Site-specific Physical Impacts and Disturbance to known mountain yellow-legged frog locations: 

Proposed motorized route additions were evaluated to determine site-specific impacts to known mountain 

yellow-legged frog (MYLF) locations for each of the alternatives. Native surfaced routes that cross or 

intersect MYLF streams and ponds have the greatest potential to disturb MYLF, kill and crush MYLF egg 

masses and to alter stream banks and deliver sediment which can degrade MYLF habitat condition. In 

addition, proposed motorized route additions that are within RCAs or have the potential to deliver 

sediment to known MYLF locations were also evaluated by the alternatives.

Change in Class of Vehicle: Changing the class of vehicle on a particular route potentially changes 

the impacts to soil and water resource due to changes in the road surface (i.e. from smooth surfaced to 

rough surfaced) (see Chapter 3.02, Watershed Resources: Geology, Soil, and Hydrology). If the route 

changes from smoothed surfaced to native surfaced (rough surfaced), the change in class of vehicle may 

result in increased sediment and erosion risk to MYLF habitat. The change in class of vehicle and 

associated maintenance downgrades is evaluated for their potential to affect selected 7th field watersheds 

that may have suitable habitat for the MYLF. 

Wet Weather Seasonal Closures: Wet weather seasonal restrictions on native surfaced roads and 

routes are analyzed under “Effects Common to All Aquatic Species.”

Reopened ML 1 Roads: Reopening ML 1 roads within any MYLF HUC7 watersheds has the 

potential to adversely impact MYLF habitats through habitat modification from increased sedimentation 

and changes in riparian habitat cover; therefore the reopening of ML 1 roads are analyzed for the 

alternatives.

Route Density within Riparian Conservation Areas (RCAs): route densities of native surfaced 

routes within RCAs were evaluated to compare the overall effects of all motorized routes (including 

existing routes and routes unauthorized to motorized public use) for the alternatives within each 7th field 

watershed occupied by mountain yellow-legged frog (MYLF). According to Chapter 3.02 (Watershed 

Resources: Geology, Soil, Hydrology), Level 2 roads and below have the greatest potential for off-site 

sediment delivery into streams and lakes. Therefore, this effects analysis includes route density of all 

native surfaced motorized routes. Route density provides a relative index to measure the potential indirect 

effects to occupied habitat of MYLF from increased sedimentation from routes. Thresholds for route 

density have not been established, however, route density provides a relative way to compare the effects 

of the alternatives.

Stream Crossing Density within RCAs: The 7th field watersheds occupied by mountain yellowlegged frog were evaluated for the crossing density of native surfaced motorized routes within RCAs to 

compare direct and indirect effects of motorized routes for the alternatives. Route crossing density 

provides a way to measure the potential direct and indirect effects to MYLF and habitat. Direct effects 

include potential MYLF mortality as a result of use of motorized crossings of occupied MYLF streams. 

Indirect effects include changes to channel and streambank characteristics and changes in vegetation 

structure. Thresholds for motorized crossing route density have not been established, however, route 

crossing density provides a relative way to compare the effects of the alternatives.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 477

Direct and Indirect Effects

Cross Country Travel. Under Alternative 1, no action, motorized cross country travel would continue on 

22,717 Riparian Conservation Areas (RCAs) acres within MYLF HUC7 watersheds, where the potential 

for adversely affecting MYLF habitat could occur by increasing sedimentation and altering streamside 

vegetation. Under the action alternatives, the prohibition of cross country travel results in prohibiting 

motorized use on 22,717 RCA acres, including approximately 49 to 52 RCA miles and from 96 to 101

motorized crossings (Alternatives 5 and prohibit the least, Alternative 3 prohibits the most). Cross country 

travel prohibitions would likely reduce the potential for sedimentation and alteration of streamside 

vegetation, and therefore benefit MYLF habitat.

NFTS Additions – Motorized Stream Crossings and RCA Miles

Number of Native Surfaced, Motorized Stream Crossing Additions within MYLF 7th Field 

Watersheds. The number of native surfaced, motorized stream crossings, proposed for addition to the 

NFTS, are assessed for the alternatives, and provides a useful way to compare potential changes in 

sediment delivery within MYLF HUC7 watersheds. Alternative 1 poses the greatest risk of increased 

sedimentation where 101 motorized stream crossings are associated with the continuance of cross country 

travel on existing unauthorized motorized routes. In decreasing order, Alternatives 5, 6, 2, 4, and 7 would 

result in the addition of 1 to 5 native surfaced, motorized route crossings. Alternative 3 does not add 

motorized route crossings to the NFTS, and therefore sedimentation or streamside vegetation would not 

be affected within any MYLF HUC7 watershed.

Table 3.03-144. Mountain Yellow-legged Frog 7th Field Watersheds - Number of Native Surfaced, Stream 

Crossings Associated with Motorized Route Additions and Cross Country Prohibitions

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Motorized Stream crossings 

associated with proposed motorized 

route additions to NFTS* (negative 

impact)

101 3 0 1 5 5 1

Closed by previous NEPA decisions, 

pending implementation

2 2 2 2 2 2 2

Motorized Stream Crossings that 

would be unauthorized to motorized 

use with the prohibition of cross 

country travel (positive impact

0 98 101 100 96 96 100

*Alternative 1 includes motorized stream crossings that would remain with the continuance of cross country travel on existing

unauthorized routes, while all the action alternatives include motorized crossing additions.

RCA Miles of Proposed Additions to the NFTS within MYLF 7th Field Watersheds. The miles of 

proposed motorized route additions to the NFTS within RCAs were assessed for the alternatives, and 

provide additional information to assess the potential for off-site sediment delivery into MYLF habitats at 

the HUC7 level. Alternative 1 poses the greatest risk to increased sedimentation potential from 51.8 RCA 

miles of unauthorized motorized routes that would remain due to not prohibiting cross country travel. 

Similar to stream crossing numbers, Alternatives 2, 4, 5, 6, and 7 propose to add between 0.6 and 2.5
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

478 – Tahoe National Forest

RCA miles (Alternatives 4 and 7add the least, Alternative 5 adds the most) of motorized routes to the 

NFTS. Alternative 3 does not add motorized routes to the NFTS, and therefore changes to sedimentation 

or streamside vegetation would not occur within any MYLF HUC7 watershed.

Table 3.03-145. RCA Miles of Proposed Route Additions and Cross Country Prohibitions within MYLF HUC7 

Watersheds

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Motorized route additions within RCAs* (negative impact) 51.8 1.2 0 0.6 1.8 2.5 0.5

Routes closed by previous NEPA decisions, pending 

implementation (positive impact)

2.4 2.4 2.4 2.4 2.4 2.4 2.4

Motorized routes within RCAs that would be prohibited to 

cross country travel (positive impact) 

0 50.5 51.8 51.2 49.9 49.3 51.3

*Alternative 1 includes motorized stream crossings that would remain with the continuance of cross country travel on existing

unauthorized routes, while all the action alternatives include motorized crossing additions.

Changes to the NFTS

Change in Class of Vehicles. For each of the alternatives, Table 3.03-146 displays the effects of proposed 

changes in class of vehicles and the associated changes in maintenance standards that have to potential to 

increase the risk of delivering sedimentation and erosion to MYLF HUC7 watersheds. Alternatives 2, 4, 

5, 6, and 7 would result in changes to road maintenance levels potentially resulting in changes from 

smooth surfaced roads to rough surfaced roads. This change in road surface type has a higher potential to 

result in increased sedimentation to MYLF habitat affected by between 2 to 17 native surfaced, crossings 

and from approximately 1 to 5 miles of motorized routes.

Reopened ML 1 Roads. Under Alternatives 5 and 6, ML 1 Road SV-005 would be reopened within

the Perazzo Canyon HUC7 watershed (Table 3.03-147). A MYLF site occurs within Perazzo Creek near 

the confluence to the Little Truckee River. Road SV-005 is located upstream of the known MYLF site and 

connects to two NFTS roads. SV-005 is nearest to Perazzo Creek about 1 mile south of the known MYLF 

site and is connected to an existing system road on the side opposite to the creek. The route is located on 

less than 5% slope and surveys indicate that some sediment has come off of the route, however, 

maintenance of existing waterbars would mitigate these effects. Therefore, there is a low likelihood that 

that reopening Road SV-005 would capture and deliver sediment to MYLF habitat in Perazzo Creek, and 

therefore effects to MYLF would likely be low to nonexistent.

The remaining alternatives would not affect MYLF habitat, since reopening ML 1 roads are not 

proposed within the RCAs of MYLF HUC7 watersheds.

Table 3.03-146. Mountain Yellow-Legged Frog – as a Result of the Change in Class of Vehicles as Measured 

by Native Surfaced, Motorized Crossings and Motorized Route Miles

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Number of Native Surfaced Crossings where changed 

maintenance standards result in smooth surfaced to native 

surfaced crossings

0 15 0 2 15 13 2

RCA Motorized Route Miles where changed maintenance 

standards result in smooth surfaced to native surfaced crossings

0 5.1 0 1.1 5.1 5.0 1.1
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 479

Site-specific Physical Impacts and Disturbance to Known Mountain Yellow-legged

Frog Locations: On the Tahoe NF, MYLF has been documented from 25 7th field watersheds. Table 3.03-

147 displays the MYLF 7th field watersheds (HUC7) where proposed motorized route additions are 

located and shows the relationship of proposed unauthorized routes with known MYLF locations. 

Potential site-specific adverse and beneficial impacts at the HUC7 scale are described.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

480 – Tahoe National Forest

Table 3.03-147. Direct and indirect impacts of proposed motorized route additions in relation to known mountain yellow-legged frog locations by 7th

field watersheds

7th Field Watershed 

Name

Route ID/ 

Description for 

Action 

Alternatives

Reopened 

ML1 Road 

ID

Direct and Indirect Impacts Beneficial Impacts

Alder Creek No proposals. No 

proposals.

No effect to one MYFL site. All action alternatives prohibit cross country travel on 4 of 9 

existing intermittent/perennial NFS crossings

Boca Reservoir D_N72-1_a (Alt 

6), N894-2-11 (Alt 

5), TKN-M1,TKNJ2 (Alt 2,4,5,6,7); 

TKN-Q1 (Alt 

2,5,6).

No 

proposals.

MYLF sighting east of Boca Res: TKN-M1 & TKNQ1, and TKN-J2 not connected to MYLF location. Alt 

5 proposal N894-2-11 comes off of system road not 

likely to affect MYLF habitat. D_N72-1_a, Alt 6 

proposal is not connected to MYLF site over 1 mile 

to the south.

Proposed action alternatives prohibit cross country travel on 

up to 15 of 36 existing intermittent/perennial NFS crossings.

Canyon CreekSawmill LakeYRS-003b (Alt 

2,5,6).

No 

proposals.

No impact to MYLF site at south edge of HUC7, 

YRS-003b at top end of watershed > 3 miles from 

frog site and not connected.

Proposed action alternatives prohibit cross country travel on 

up to 3 of 4 existing intermittent/perennial NFS crossings.

Fordyce Lake SV-004 (Alt 2,5,6) 

YRS-AF (Alt 

2,4,5,6,7).

No 

proposals.

Multiple MYLF sites. SV-004 is 1 mile east of MYLF 

site not connected to sites and will not impact MYFL. 

YRS-AF is adjacent to MYFL site and has low 

potential to impact MYLF.

Proposed action alternatives prohibit cross country travel on 

up to 3 of 25 existing intermittent/perennial NFS crossings

Headwaters North 

Fork American River

No proposals. No 

proposals.

No effects to one MYFL site at southernmost edge 

of watershed.

Proposed action alternatives prohibit cross country travel on 0 

of 13 existing intermittent/perennial NFS crossings.

Headwaters North 

Yuba River

No proposals No 

proposals.

No effects to one MYFL site at northern boundary of 

watershed.

Proposed action alternatives prohibit cross country travel on 6 

of 26 existing intermittent/perennial NFS crossings.

Headwaters South 

Yuba River

TKN-J-4 (Alt 

2,5,6,7)TKN-J5 

(Alt 2,5,6,7).

No 

proposals.

TKN-J4 and TKN-J5 in northern part of HUC7 above 

So. Yuba Rr, MYLF site in southern part of HUC7 on 

opposite side of So. Yuba Rr. on private land. TKN-J 

4 and TKN-J5 not connected. 

Proposed action alternatives prohibit cross country travel on 1 

of 22 existing intermittent/perennial NFS crossings.

Independence Creek SV-P11 (Alt 

2,5,6), D_350-10 

(Alt 6).

No 

proposals.

Two MYLF sites. SV-P11 in same watershed, 1 

ridge over, connection at bottom, route is in good 

condition, very little erosion and sediment off route, 

northern section has been ripped and 

decommissioned, south half very low use, effects to 

MYLF habitat not expected. Route D_350-10 has a 

low likelihood of delivering sediment to MYLF sites.

All action alternatives prohibit cross country travel on 4 of 19 

existing intermittent/perennial NFS crossings.

Little Truckee RiverSaddle MeadowSV-P8 (Alt 

2,5,6,7), D_S260 

(Alt 6).

No 

proposals.

One MYLF site. SV-P8 is not connected to MYLF 

sites.

Proposed action alternatives prohibit cross country travel on 2 

intermittent/perennial NFS crossings.

Lower Fordyce Creek No proposals No 

proposals.

No effect to MYLF site. Proposed action alternatives prohibit cross country travel on 0 

of 25 existing intermittent/perennial NFS crossings.

Lower Sagehen 

Creek

No proposals No 

proposals.

No effect to MYLF site. Proposed action alternatives prohibit cross country travel 1 of 

14 existing intermittent/perennial NFS crossings.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 481

7th Field Watershed 

Name

Route ID/ 

Description for 

Action 

Alternatives

Reopened 

ML1 Road 

ID

Direct and Indirect Impacts Beneficial Impacts

Lower Salmon Creek YRN-004 (Alt 2,5). No 

proposals.

MYLF site near lakes, YRN-004, not connected to 

MYLF site and therefore no impacts to MYLF

All action alternatives prohibit cross country travel on 1 of 3 

existing intermittent/perennial NFS crossings.

Middle Martis Creek No proposals No 

proposals.

No effect Proposed action alternatives prohibit cross country travel on 0 

of 35 existing intermittent/perennial NFS crossings.

Middle Truckee RiverLower Prosser CreekTKN-M1 (Alt 

2,4,5,6,7), TKNPP (Alt 6).

No 

proposals.

TKN-M1 and TKN-PP

not connected to MYLF site, not likely to affect 

MYLF.

All action alternatives prohibit cross country travel on 3 of 9 

existing intermittent/perennial NFS crossings.

North Creek No proposals. No 

proposals.

2 MYLF sites not affected. All action alternatives prohibit cross country travel on 3 of 9 

existing intermittent/perennial NFS crossings.

North Yuba RiverHaskell Creek

No proposals. No 

proposals.

Two MYLF sites not affected. Proposed action alternatives prohibit cross country travel on 

up to 6 of 17 existing intermittent/perennial NFS crossings.

North Yuba RiverHoward Creek

No proposals. No 

proposals.

No effects to two MYLF sites in upper watershed. Proposed action alternatives prohibit cross country travel on 

up to 10 of 17 existing intermittent/perennial NFS crossings.

Perazzo Canyon No proposals. SV-005 (Alt 

5, 6)

MYLF site in Perazzo Ck (near confluence to Little 

Truckee Rv) is downstream of SV-005,. MYLF not 

likely affected by SV-005 which connects to 2 NFTS 

roads.

All action alternatives prohibit cross country travel on 4 of 14 

existing intermittent/perennial NFS crossings.

Prosser Creek No proposals. No 

proposals.

One MYLF site on Prosser Creek not affected. Proposed action alternatives prohibit cross country travel on 

up to 4 of 16 existing intermittent/perennial NFS crossings.

Rattlesnake Creek No proposals. No 

proposals.

Multiple MYLF sites not affected. Proposed action alternatives prohibit cross country travel on 5 

of 9 existing intermittent/perennial NFS crossings.

South Yuba RiverLower Castle Creek

TKNJ-4 No 

proposals.

TKN-J4 on watershed boundary south of MYLF site 

with no connection and no impacts. Route is ~1 mile 

from MYLF site.

All action alternatives prohibit cross country travel on 5 of 8 

existing intermittent/perennial NFS crossings.

Squaw Creek No proposals. No 

proposals.

No effects Proposed action alternatives prohibit cross country travel on 0 

of 20 existing intermittent/perennial NFS crossings.

Upper Cold Stream D_5_b, D_89-

55_a, D_89-55_c 

(Alt 6). 

No 

proposals.

SVP-7e in headwaters no connection with MYLF 

along main channel and highway, no impacts 

expected.

Proposed action alternatives prohibit cross country travel on 

10 of 10 existing intermittent/perennial NFS crossings.

Upper Five Lakes No proposals. No 

proposals.

No effects Proposed action alternatives prohibit cross country travel on 1 

of 10 existing intermittent/perennial NFS crossings.

Upper Sagehen Creek No proposals. No 

proposals.

No impacts to multiple MYLF sites. All action alternatives prohibit cross country travel on 5 of 8 

existing intermittent/perennial NFS crossings.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

482 – Tahoe National Forest

Route Density within Riparian Conservation Areas (RCAs): Route density within Riparian 

Conservation Areas (RCAs) for all native surfaced motorized routes within 7th field watersheds with 

known observations of mountain yellow-legged frogs was determined for the proposed alternatives. 

Alternative 1 poses the greatest risk of high route densities within Riparian Conservation Areas (RCAs) 

(Table 3.03-148, Figure 3.03-15). Under Alternative 1, 64% of the HUC7 watersheds with MYLF 

detections fall under the highest (32%) and moderately high (32%) categories for motorized route density 

(native surfaced routes). The action alternatives have decreasing RCA route densities compared to 

Alternative 1, ranging between 48% (Alternatives 2 and 5) and 36% (Alternatives 3, 4, and 7) of MYLF 

HUC7 watersheds that fall within the highest route densities category to moderately high route density 

category.

Table 3.03-148. Number 7th Field Watersheds (HUC7s) with Mountain Yellow-legged Frog Sites by RCA Route 

Density Category or Number (Percent) of HUC7s by Route Density Category (n=25)

Alternatives Highest (%) Moderately High (%) Moderately Low (%) Lowest (%)

Alt 1 8 (32%) 8 (32%) 6 (24%) 3 (12%)

Alt 2 8 (32%) 4 (16%) 7 (28%) 6 (24%)

Alt 3 6 (24%) 4 (16%) 7 (28%) 8 (32%)

Alt 4 6 (24%) 4 (16%) 7 (28%) 8 (32%)

Alt 5 8 (32%) 4 (16%) 7 (28%) 6 (24%)

Alt 6 6 (24%) 5 (20%) 7 (28%) 7 (28%)

Alt 7 6 (24%) 4 (16%) 7 (28%) 8 (32%)
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 483

Figure 3.03-15. Number of 7th Field Watersheds within RCA Route Density Categories with Known Mountain 

Yellow-legged Frogs Locations

Stream Crossing Density within Riparian Conservation Areas (RCAs): RCA stream crossing 

density was assessed by route density categories of highest (10.4–20.4 crossings/sq. mile), moderately 

high (7.3-10.3 crossings/sq. mile), moderately low (4.2-7.6 crossings/sq. mi.), and lowest (0-4.1 

crossing/sq. mi.) within 7th field watersheds (HUC7s) with known mountain yellow-legged frog 

observations (Table 3.03-149 and Figure 3.03-16). Alternative 1 poses the greatest direct impacts to 

mountain yellow-legged frogs (MYLF) from stream crossing densities where frogs may be disturbed 

and/or killed; and MYLF aquatic habitat conditions can be impacted from bank alteration and sediment 

input associated with motorized route crossings. Under Alternative 1, 40% of HUC7 watersheds with 

known MYLF detections are within the highest (24%) and moderately high (16%) route crossing density, 

and alternatively Alternative 1 has the least proportion of MYLF HUC7 watersheds with low crossing 

densities (20%). Alternatives 2 and 5 pose the next greatest risk to MYLF from stream crossings where 

40% of MYLF HUC7 watersheds are within the highest (20%) and moderately high (20%) motorized 

crossing density categories. Alternative 6 has slightly lower route densities within both the highest and the 

moderately high crossing density categories compared to Alternatives 1, 2, and 5.

Alternatives 3, 4, and 7 have the lowest route densities of all the alternatives, and similarly reduces 

the potential direct and indirect effects of unauthorized motorized routes where only 8 % of HUC7 

watersheds with route crossing densities within the highest category and the most HUC7 watersheds 

(44%) in the lowest crossing density category. Within all the action alternatives, unmanaged cross country 

Riparian Conservation Area Native Surface, Motorized 

Route Density by Density Category - Moutain Yellowlegged Frog HUC7s

0%

20%

40%

60%

80%

100%

1 2 3 4 5 6 7

Alternatives

HUC7 Watersheds with 

MYLF

 Observations

Highest

Mod High

Mod Low

Lowest
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

484 – Tahoe National Forest

motorized travel would be prohibited, and over time as unauthorized routes are physically rehabilitated, 

MYLF and their habitat would benefit in the long term.

Table 3.03-149. Number (Percent) 7th Field Watersheds (HUC7s) with Mountain Yellow-legged Frog Sites by 

Native Surfaced, Motorized Crossing Density Category 

Alternatives Highest (%) Moderately High (%) Moderately Low (%) Lowest (%)

Alt 1 6 (24%) 4 (16%) 10 (40%) 5 (20%)

Alt 2 5 (20%) 5 (20%) 7 (28%) 8 (32%)

Alt 3 2 (8%) 6 (24%) 6 (24%) 11 (44%)

Alt 4 2 (8%) 6 (24%) 6 (24%) 11 (44%)

Alt 5 5 (20%) 5 (20%) 7 (28%) 8 (32%)

Alt 6 4 (8%) 4 (8%) 9 (28%) 8 (32%)

Alt 7 2 (8%) 6 (24%) 6 (24%) 11 (44%)

Figure 3.03-16. Number of 7th Field Watersheds by Native Surfaced, Motorized Crossing Density Category for 

Known Mountain Yellow-legged Frog Locations

Cumulative Effects

Cumulative Effects Boundary in Space and Time

The geographic boundary for assessing cumulative effects to the MYLF is suitable habitat on the Tahoe 

NF above 6,000 feet within high elevation ponds and slow moving portions of perennial and intermittent 

streams. This geographic boundary is sufficiently large to encompass historic and potential MYLF habitat 

on the Tahoe NF. Any larger boundary could dilute the effects of past, present, and future cumulative 

Native Surface, Motorized Crossing Density - 

Mountain Yellow-legged Frog HUC7s

0%

20%

40%

60%

80%

100%

1 2 3 4 5 6 7

Alternatives

Percent of HUC7 

Watersheds with MYLF 

Observations

Highest

Mod High

Mod Low

Lowest
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 485

impacts to this species. The timeframe for assessing cumulative impacts in the past includes activities that 

occurred within the last 50 to 100 years. Reasonably foreseeable future impacts expand out to 

approximately 25 years into the future.

Cumulative Effects of Past, Present, and Reasonably Foreseeable Actions

Historically the mountain yellow-legged frog was extremely abundant within high elevation aquatic 

ecosystems of the Sierra Nevada Mountains (Grinnell and Storer 1924, Zweifel 1955, In Lannoo 2005). 

Beginning around the 1970s, the mountain-yellow frog has undergone dramatic population declines 

throughout the Sierra Nevada (Knapp and Matthews 2000, ranging between 50-90% declines of their 

historic localities (USFWS 2004).

Many past and current cumulative impacts have contributed to the decline in mountain yellow-legged 

frog numbers and distribution. The decline of the MYLF has largely been attributed to the introduction of 

salmonid fishes during the last century (Bradford et al. 1993, Knapp 1996). 

Other factors that have contributed to cumulative impacts to the species includes pesticides, 

ultraviolet radiation; bacterial, fungal, and viral pathogens; acidification from the atmospheric deposition; 

nitrate deposition; livestock grazing; recreational activities (including motorized); and drought have all 

been identified as potential factors affecting the species and its habitat (USDA 2001).

Historic livestock grazing likely had a significant cumulative impact to this species and their habitat. 

Historic livestock grazing evidence indicates that heavy livestock use in the Sierra Nevada led to riparian 

habitat degradation across much of the Sierra Nevada. Livestock trampling has the potential to directly 

kill all life stages of MYLF. The greatest potential of mortality risk from livestock trampling is expected 

to occur when adult MYLF aggregate and lay egg masses in the early season, and during metamorphosis, 

when juveniles are metamorphosing along aquatic margins. Current standards and guidelines in the Sierra 

Nevada Forest Plan Amendment were implemented to reduce the risk of trampling by livestock (USDA 

2004). Known MYLF habitat sites currently overlap with 5 active livestock grazing allotments (Canyon 

Creek, Devils Peak, Euer Valley, Independence, and Perazzo Meadows). Potential mountain yellowlegged frog habitat overlaps with an additional 29 allotments. Management direct including standards and 

guidelines for grazing should reduce potential grazing impacts from livestock grazing.

Introduced trout species within high mountain lakes has severely affected mountain yellow-legged 

frog population trends in the Sierra Nevada including the Tahoe NF. In recent years, the California 

Department of Fish and Game has actively addressing this issue to proactively manage for mountain 

yellow-legged frog restoration opportunities while still providing a recreational fisheries within high 

mountain lakes. Recent experimental efforts to remove introduced trout species from high mountain lakes 

has shown that MYLF will recover once introduced trout have been removed.

Historic vegetation management and fuels reduction projects have likely contributed to past and 

present cumulative effects, especially if projects occurred adjacent to MYLF aquatic habitats. Ground 

disturbing activities including timber harvest and fuels treatment projects (burning and mastication 

projects) potentially caused direct mortality to this species which may have affected the abundance of the 

species on the Tahoe NF. In general, current vegetation and fuels projects are designed to reduce potential 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

486 – Tahoe National Forest

impacts on MYLF habitats, and therefore, minimize disturbance to the species. However, as MYLF 

migrate between breeding sites, and between breeding sites and overwintering sites, there is some 

potential for direct impacts from being crushed or burned from vegetation and fuels projects. In general 

the magnitude of this happening across the range of the MYLF frog habitats on the Tahoe NF should be 

limited given the timing of MYLF migration which is in the spring, with the exception to spring 

prescribed burning projects. In general, the adverse impacts of spring burning is expected to be low given 

the relatively low amount that occurs on the Forest within an average year.

Under Alternative 1, cumulative effects from unauthorized routes would be greatest within HUC7 

watersheds occupied by MYLF would have the highest RCA route densities and the highest route 

crossing densities. In addition, 24 of 25 (96%) of MYLF HUC7 watersheds would have cross country 

travel and continued route proliferation. Direct and indirect impacts of unauthorized motorized routes in 

Alternative 1 would result in considerable cumulative impacts to known MYLF sites where 

approximately 64% of HUC7 watersheds with MYLF observations have high to moderately high RCA 

route densities that may contribute to habitat degradation from off-site sedimentation. In addition, under 

Alternative 1, 64% of HUC7 watersheds with known MYLF detections are within the highest or 

moderately high route crossing density categories which have the potential to degrade stream condition by 

altering streambank vegetation and stream hydrology. Under Alternative 1, unauthorized route 

proliferation would likely continue and increase at an accelerated rate in the future, potentially increasing 

sediment delivery and alteration of streambank vegetation and hydrologic condition which may affect the 

abundance and distribution on the Tahoe NF. Already declining population trends of this species could be 

significantly affected by Alternative 1 in the long term.

Alternatives 2 and 5 also add to existing cumulative impacts to the MYLF, though impacts are 

considerably less than Alternative 1 as a result of the closure of a significant number of miles of 

motorized routes within RCAs and reduction in the number of route crossings. Proposed routes sitespecifically has the potential to directly and indirectly degrade habitat condition within known mountain 

yellow-legged frog sites within 28% of all MYLF HUC7s (n=25). At the 7th field watershed scale, under 

Alternatives 2 and 5, 40% of MYLF HUC7 watersheds have route crossing densities within the highest 

(20%) and moderately high (20%) motorized crossing density categories.

Alternative 2 cumulatively affects 3 of 25 (12%) MYLF HUC7 sites. Alternatives 4, 6, and 7 affect 

MYLF habitat within 2 of 25 (8%) HUC7 watersheds from short routes accessing dispersed recreation 

sites. The potential for off-site sedimentation from these short route segments is expected to be relatively 

low. All action alternatives have decreasing RCA route densities compared to Alternative 1, ranging 

between 48% (Alternatives 2 and 5– most) and 36% (Alternative 3, 4, and 7– least) of MYLF HUC7 

watersheds that fall within the highest route densities category to moderately high route density category.

For all the action alternatives, cross country motorized travel, including on routes unauthorized to 

motorized travel, would be prohibited. In addition, the majority these routes would benefit MYLF in the 

long-term once they are rehabilitated through obliteration or other means. Non-motorized use (hiking, 

mountain bicycling, equestrian, etc.) may occur on routes that would be prohibited to cross country travel. 

In general, it is expected that impacts from non-motorized use would be less than motorized use. Over 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 487

time, it is expected that these unauthorized motorized routes would become revegetated and recover 

through active or passive means, and ultimately benefit MYLF in the future.

Summary of Direct, Indirect, and Cumulative Effects of Proposed Actions

Table 3.03-150 summarizes the direct, indirect, and cumulative effects of native surfaced, motorized route 

crossings within MYLF HUC 7 watersheds, from existing motorized routes, motorized route additions, 

and routes unauthorized to motorized public travel from the proposed actions, including wet weather 

seasonal restrictions, changes in class of vehicles, prohibition of cross country travel. See Chapter 3.02,

Watershed Resources: Geology, Soil, Hydrology, for more detailed information and assumptions.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

488 – Tahoe National Forest

Table 3.03-150. Mountain Yellow-legged Frog 7th Field Watersheds – Summary of Direct, Indirect, and Cumulative Effect of Proposed Actions as 

Measured by Native Surfaced, Motorized Crossings

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

RCA Acres Prohibited 

to Cross Country 

Travel

0 22,717 22,717 22,717 22,717 22,717 22,717

Stream Crossings 

Prohibited to Cross 

Country Travel

0 98 101 100 96 96 100

Native Surfaced, Motorized Stream Crossings

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Existing NFTS 

Crossings 

93 93 93 93 93 93 93

Crossing Additions* 101 3 0 1 5 5 1

Change in Class of 

Vehicles from Smooth 

Surfaced to Native 

Surfaced Crossings

0 15 0 2 15 13 2

Closed crossings 

from previous NEPA 

decisions, pending 

implementation

2 2 2 2 2 2 2

Total Motorized 

Stream Crossings

Prohibited to 

Motorized Use

2 85 103 100 83 85 100

Net Native Surfaced, 

Motorized Crossings

194 111 93 96 113 111 96

Wet Weather 

Seasonal Restrictions 

on all Native Surfaced 

Routes

None None None Beneficial - Wet 

Weather 

Restrictions would 

be implemented

Beneficial - Wet 

Weather 

Restrictions would 

be implemented

Beneficial - Wet 

Weather 

Restrictions would 

be implemented

None

Establishment of 

Open Areas

No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Amendments to 

Forest Plan

No Effect No Effect No Effect No Effect No Effect No Effect No Effect
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 489

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Net Direct, Indirect, 

and Cumulative Effect 

of Proposed Actions

Negative adverse 

cumulative effects 

from continued 

cross country 

travel.

Motorized cross 

country travel 

prohibited 0 acres.

Motorized use 

prohibited on 2 

crossings from 

previous NEPA 

decisions.

No additional 

protection to MYLF 

habitats from wet 

weather seasonal 

restrictions.

6th most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

22,717 RCA acres, 

including on 85 

native surfaced, 

stream crossings.

No additional 

protection to MYLF 

habitats from wet 

weather seasonal 

restrictions.

4th most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

22,717 RCA acres, 

including on 103 

native surfaced, 

stream crossings.

No additional 

protection to MYLF 

habitats from wet 

weather seasonal 

restrictions.

Most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

22,717 RCA acres, 

including on 100 

native surfaced, 

stream crossings.

Reduced 

sedimentation risk 

to MYLF habitats 

from wet weather 

seasonal 

restrictions.

3rd most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

22,717 RCA acres, 

including on 83 

native surfaced, 

stream crossings.

Reduced 

sedimentation risk 

to MYLF habitats 

from wet weather 

seasonal 

restrictions.

2nd most beneficial 

alternative.

Motorized country 

travel prohibited on 

22,717 RCA acres, 

including on 85 

native surfaced, 

stream crossings.

Reduced 

sedimentation risk 

to MYLF habitats 

from wet weather 

seasonal 

restrictions.

5th most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

22,717 RCA acres, 

including on 100 

native surfaced, 

stream crossings.

No additional 

protection to MYLF 

habitats from wet 

weather seasonal 

restrictions.

*Alternative 1 includes existing native surfaced, crossings unauthorized to motorized use, while all the action alternatives include motorized route additions.

Table 3.03-151 summarizes the direct, indirect, and cumulative effects of native surfaced, motorized RCA route miles within MYLF HUC 7 

watersheds, from existing motorized routes, motorized route additions, and routes unauthorized to motorized public travel from the proposed 

actions, including wet weather seasonal restrictions, changes in class of vehicles, prohibition of cross country travel. See Chapter 3.02, Watershed 

Resources: Geology, Soil, Hydrology, for more detailed information and assumptions.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

490 – Tahoe National Forest

Table 3.03-151. Mountain Yellow-legged Frog 7th Field Watersheds – Summary of Direct, Indirect, and Cumulative Effect of Proposed Actions as 

Measured by RCA Motorized Route Miles

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres Cross Country Travel 

Prohibited

0 22,717 22,717 22,717 22,717 22,717 22,717

Native Surfaced, Motorized Routes

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Existing RCA Miles 45.9 45.9 45.9 45.9 45.9 45.9 45.9

RCA Miles of Native Surfaced, 

Motorized Route Additions*

51.8 1.2 0 0.6 1.8 2.5 0.5

Change in Class of Vehicles 

Resulting in Maintenance 

Changed from Smooth Surfaced 

to Native Surfaced Motorized 

route miles

0 5.1 0 1.1 5.1 5.0 1.1

Reopened ML 1 Roads 0 0 0 0 0 0

Closed roads by previous NEPA, 

pending implementation 

(positive)

2.4 2.4 2.4 2.4 2.4 2.4 2.4

Total RCA Route Miles 

Prohibited to Motorized Use 

(positive)

2.4 49.1 54.2 52.5 47.3 46.7 52.6

Net NFTS Native Surfaced, 

Motorized RCA Miles

97.9 52.2 47.1 47.6 52.8 53.4 47.5

Establishment of Open Areas No Effect No Effect No Effect No Effect No Effect No Effect No Effect

Wet Weather Seasonal 

Restrictions on all Native 

Surfaced Roads and Routes

None None None Beneficial - Wet 

Weather 

Restrictions 

would be 

implemented

Beneficial - Wet 

Weather 

Restrictions 

would be 

implemented

Beneficial - Wet 

Weather 

Restrictions 

would be 

implemented

None

Amendments to Forest Plan No Effect No Effect No Effect No Effect No Effect No Effect No Effect
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 491

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Net Direct, Indirect, and 

Cumulative Effect of Proposed 

Actions

Adverse 

cumulative 

impacts from 

cross country 

cross travel 

prohibition on 0 

acres and on 2.4 

miles.

No additional 

protection to 

MYLF habitats 

from wet weather 

seasonal 

restrictions.

6th most 

beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

22,717 RCA 

acres, including 

on 49.1 RCA 

miles.

No additional 

protection to 

MYLF habitats 

from wet weather 

seasonal 

restrictions.

4th most 

beneficial 

alternative. 

Motorized cross 

country travel 

prohibited on 

22,717 RCA 

acres, including 

on 54.2 RCA 

miles.

No additional 

protection to 

MYLF habitats 

from wet weather 

seasonal 

restrictions.

Most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

22,717 RCA 

acres, including 

on 52.5 RCA 

miles. 

Reduced 

sedimentation 

risk to MYLF 

habitats from wet 

weather 

seasonal 

restrictions.

2nd most 

beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

22,717 RCA 

acres, including 

on 47.3 RCA 

miles.

Reduced 

sedimentation 

risk to MYLF 

habitats from wet 

weather 

seasonal 

restrictions.

3rd most 

beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

22,717 RCA 

acres, including 

on 46.7 RCA 

miles.

Reduced 

sedimentation 

risk to MYLF 

habitats from wet 

weather 

seasonal 

restrictions.

5th most 

beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

22,717 RCA 

acres, including 

on 52.6 RCA 

miles.

No additional 

protection to 

MYLF habitats 

from wet 

weather 

seasonal 

restrictions.

*Alternative 1 includes existing unauthorized routes, while all the action alternatives include motorized route additions.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

492 – Tahoe National Forest

Northwestern Pond Turtle: Affected Environment

The northwestern pond turtle (Clemmys marmorata marmorata) (NWPT) is listed as Sensitive on the 

Region 5 Forester’s Sensitive Species List (USDA Forest Service 1998). The northwestern pond turtle 

ranges approximately from the American River northward to the vicinity of Puget Sound with an 

elevational distribution from sea level to 6,000 feet (Stebbins 1972, In Lannoo 2005). Recent genetic 

studies support the traditional morphological subdivision of the western pond turtle into the northern 

subspecies, Clemmys marmorata marmorata (northwestern pond turtle), and the southern subspecies, 

Clemmys marmorata pallida (Gray 1995).

Habitat for the NWPT, historically, occurs in a variety of both permanent and intermittent aquatic 

habitats west of the Sierra-Cascade crest. This turtle is often restricted to areas near the banks or in quiet 

backwaters where the current is relatively slow and basking sites and refugia are available. Currently most 

populations exist in smaller streams, usually in montane areas. These streams may be either permanent or 

intermittent, but permanent streams support larger populations. Western pond turtles occur in a variety of 

water courses directly or indirectly modified by man, such as reservoirs, canals, excavated farm ponds, 

and mill ponds. This species is considered omnivorous. Aquatic plant material, beetles and aquatic 

invertebrates have been reported among their food (Stebbins 1972 and Nussbaum et al. 1983, In Lannoo 

2005). Northwestern pond turtles have been observed at less than 20 locations within the Tahoe NF. Five 

of these locations are on NFS land and the remaining are on private land or on Bureau of Land 

Management administered lands. Tahoe NF reported sightings are from the Yuba River and American 

River drainages associated with pond habitat.

Risk factors to northwestern pond turtle from roads and trails are similar to frog species described 

above.

Northwestern Pond Turtle: Environmental Consequences

Indicators used to Measure Effects

Cross Country Travel: The prohibition of cross country travel is analyzed for the alternatives to estimate 

the potential benefits and reduction in effects to NWPT 7th field watersheds from motorized cross country 

travel.

NFTS Additions (NWPT 7th field watersheds): Measures or indicators of changes in sedimentation 

and water surface shade are assessed by analyzing the number of stream crossings additions associated 

with motorized route additions to the NFTS, and the miles of motorized route additions within Riparian 

Conservation Areas (RCAs) for NWPT 7th field watersheds

Site-specific Physical Impacts and Disturbance to known northwestern pond turtle locations: 

Unauthorized motorized routes were evaluated to determine site-specific impacts to known northwestern 

pond turtle locations for each of the alternatives. Native surfaced routes that cross or intersect ponds 

occupied by NWPT have the greatest potential to disturb, crush and kill the pond turtle, and to alter 

stream banks and deliver sediment which can degrade pond turtle habitat condition. In addition, any 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 493

unauthorized motorized routes that are within RCAs or has the potential to delivery sediment to known 

NWPT locations were also evaluated for their potential to contribute to indirect effects by the alternatives.

Establishment of “Open Areas”: Establishment of “Open Areas” would not affect the northwestern 

pond turtle, since none of the “Open Areas” would affect suitable pond turtle habitats. Therefore, no 

further analysis is warranted.

Change in Class of Vehicles: Changing the class of vehicle on a particular route potentially changes 

the impacts to soil and water resource due to changes in the road surface (i.e. from smooth surfaced to 

rough surfaced) (see Chapter 3.02, Watershed Resources: Geology, Soil, and Hydrology). If the route 

changes from smoothed surfaced to native surfaced (rough surfaced), the change in class of vehicle may 

result in increased sediment and erosion risk to NWPT habitat. The change in class of vehicle and 

associated maintenance downgrades is evaluated for their potential to affect selected 7th field watersheds 

that may have suitable habitat for the NWPT.

Wet Weather Seasonal Closures: Proposed wet weather seasonal restrictions on native surfaced 

roads and trails are analyzed under “Effects Common to All Aquatic Species.

Reopened ML 1 Roads: Reopened ML 1 roads within pond turtle habitats are analyzed for the 

alternatives.

RCA Motorized Route Density within Northwestern Pond Turtle 7th Field Watersheds: Route 

densities of native surfaced routes within RCAs were evaluated to compare the overall effects of all 

motorized routes (including existing and unauthorized) for the alternatives within each 7th field watershed 

occupied by the northwestern pond turtle. According to Chapter 3.02 (Watershed Resources: Geology, 

Soil, Hydrology), native surfaced roads have the greatest potential for off-site sediment delivery into 

streams and lakes. Therefore, this effects analysis includes route density of all native surfaced motorized 

routes. Route density provides a relative index to measure the potential indirect effects to occupied habitat 

of the NWPT from increased sedimentation from routes. Thresholds for route density have not been 

established, however, route density provides a relative way to compare the effects of the alternatives.

Stream Crossing Density within RCAs: The 7th field watersheds occupied by northwestern pond 

turtle were evaluated for the crossing density of native surfaced motorized routes within RCAs to 

compare direct and indirect effects of motorized routes for the alternatives. Route crossing density 

provides a way to measure the potential direct and indirect effects to the northwestern pond turtle and 

habitat. Direct effects include potential pond turtle mortality as a result of use of motorized crossings of 

occupied pond turtle. Indirect effects include changes to channel and streambank characteristics and 

changes in vegetation structure. Thresholds for motorized crossing route density have not been 

established, however, route crossing density provides a relative way to compare the effects of the 

alternatives.

Direct and Indirect Effects

Cross Country Travel. Under Alternative 1, no action, motorized cross country travel would continue on 

7,986 Riparian Conservation Areas (RCAs) acres within NWPT HUC7 watersheds, where the potential 

for adversely affecting NWPT habitat could occur by increasing sedimentation and altering streamside 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

494 – Tahoe National Forest

vegetation (Table 3.03-152). Under the action alternatives, the prohibition of cross country travel results 

in prohibiting motorized use on 7,986 RCA acres, including on 10.4 to 16.3 RCA miles and from 31 to 47

native surfaced, motorized crossings (Alternative 5 prohibits the least, Alternative 3 prohibits the most). 

Cross country travel prohibitions would likely reduce the potential for sedimentation and alteration of 

streamside vegetation, and therefore benefit NWPT habitat.

Table 3.03-152. Cross Country Travel on Native, Surfaced Routes within NWPT 7th Field Watersheds

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Number crossings prohibited to cross country 

travel 1 44 47 45 31 40 47

RCA miles where cross country travel prohibited 0.5 16.3 17.1 16.7 10.4 13.9 16.8

RCA acres where cross country travel prohibited 0 7,986 7,986 7,986 7,986 7,986 7,986

Change in Class of Vehicles (Reopening ML 1 Road and Changed Maintenance Levels). Several ML 

1 roads are proposed for reopening in the Cherokee Creek HUC7 watershed where there are known pond 

turtle locations. However, none of the ML1 roads proposed for reopening or changes to maintenance 

levels from smooth surfaced to native surfaced would affect NWPT habitat under any of the action 

alternatives.

NFTS Additions – Motorized Stream Crossings and RCA Miles

Number of Native Surfaced, Motorized Stream Crossing Additions within NWPT 7th Field 

Watersheds. The number of native surfaced, motorized stream crossings, proposed for addition to the 

NFTS, are assessed for the alternatives, and provides a useful way to compare potential changes in 

sediment delivery within NWPT HUC7 watersheds. Alternative 1 poses the greatest risk of increased 

sedimentation where 47 native surfaced, stream crossings are associated with the continuance of cross 

country travel on existing unauthorized routes (Table 3.03-153). This includes 1 crossing that was closed 

in a previous NEPA decision that is pending implementation.

All the action alternatives would reduce the number of crossings within NWPT HUC7 watersheds. In 

increasing order, Alternatives 4, 6, 2, and 5 would result in the addition of 2 to 16 native surfaced, 

motorized crossings. Alternatives 3 and 7 would not result in additional native surfaced, motorized stream 

crossings within any NWPT HUC7 watersheds, and therefore sedimentation or streamside vegetation 

would not be affected.

Table 3.03-153. Northwestern Pond Turtle 7th Field Watersheds - Number of Native Surfaced, Stream 

Crossings Associated with Motorized Route Additions

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Motorized Stream crossings associated with proposed 

motorized route additions to NFTS (negative impact)

47 3 0 2 16 7 0

*Alternative 1 includes motorized stream crossings that would remain with the continuance of cross country travel on existing 

unauthorized routes, while all the action alternatives include motorized crossing additions.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 495

RCA Miles of Proposed Motorized Route Additions within NWPT 7th Field Watersheds. The 

miles of proposed motorized route additions to the National Forest Transportation System (NFTS) within 

RCAs were assessed for the alternatives, and provide additional information to assess the potential for 

off-site sediment delivery into NWPT habitats at the HUC7 level. Alternative 1 poses the greatest risk to 

increased sedimentation potential from approximately 17 RCA miles of motorized unauthorized routes 

that would remain due to not prohibiting cross country travel (Table 3.03-154). Similar to stream crossing 

numbers, Alternatives 2, 4, 5, 6, and 7 propose to add between 0.2 and 6.6 RCA miles (Alternatives 4 and 

7 add the least, Alternative 5 adds the most) of motorized routes to the NFTS. Alternative 3 does not add 

motorized routes to the NFTS, and therefore changes to sedimentation or streamside vegetation would not 

occur within any NWPT HUC7 watershed.

Table 3.03-154. Northwestern Pond Turtle - Miles of Proposed Route Additions within HUC7 Watersheds

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Miles of proposed motorized route additions within 

RCAs* (negative impact)

16.5 0.8 0 0.4 6.6 3.1 0.2

*Alternative 1 includes motorized stream crossings that would remain with the continuance of cross country travel on existing

unauthorized routes, while all the action alternatives include motorized crossing additions.

Site-specific Physical Impacts and Disturbance to known Northwestern Pond Turtle locations:

Within the boundaries of the Tahoe NF, the northwestern pond turtle is known from 5 locations on NFS 

lands and 13 locations on private and BLM administered lands. These pond turtle locations are known 

from nine 7th field watersheds within the boundary of the Tahoe NF. Proposed motorized route additions 

and reopening of ML 1 roads within nine 7th field watersheds that have northwestern pond turtle locations 

are shown in Table 3.03-155. Existing unauthorized routes under Alternative 1 could potentially affect the 

pond turtles and their habitats within the South Yuba River Pierce Meadow, Headwaters North Fork 

American River, and North Fork of North Fork American River-Blue Canyon watersheds. The action 

alternatives either do not propose motorized route additions or reopens any ML 1 roads that would 

directly or indirectly affect the pond turtle. Numerous private land motorized routes may contribute to 

direct and indirect impacts to the pond turtle.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

496 – Tahoe National Forest

Table 3.03-155. Description of motorized route additions for the action alternatives in relation to known northwestern pond turtle locations within 7th

field watersheds

Watershed Name Route ID/Description Reopened ML1 Road ID Direct and Indirect Impacts 

Bullards Bar Reservoir-Bridger 

Creek

D_Y-125_a (Alt 2,4,5,6). None D_Y-125_a, not connected, no effect to pond 

turtle sites near Bullards Bar Res.

Cherokee Creek YRN-008 (Alt 2,4,5,6); 491-3-

1_p, 491-3-2_p (Alt 5,6); 

D_35_a,b, D_491-6_a,b (Alt 

2,4,5,6); N39-6 (Alt 5).

0025-009, 0491-003 (Alt 2,4,5,6); 25-

9-3_p, 25-9_p, 35-3_p, 35-4_p, 35-4-

1_p, 39-9_p, 491-3_p (Alt 5,6)

H39-12, N25-1-1, N25-3, N25-5, N25-

6-1, N25-7, N25-9-1, N25-9-2, N35-1, 

N35-2, N35-3-1, N35-3-2, N35-6, N35-

7, N39-4, N39-5, N39-5-1, N39-5-2, 

N39-7, N39-8-1, N491-1, N491-3-1, 

N55-2 (Alt 5).

YRN-008 and Cal Ida Network (numerous 

routes) not likely to impact turtle site, not 

connected

D_35_a,b, D_491-6_a,b – would not affect pond 

turtle site.

Lower Oregon Creek None None None 

Lower Middle Yuba River H18N49Y (Alt 5). None H18N49Y does not affect turtle sites

Middle Yuba River-Indian Creek None None None

South Yuba River-Pierce 

Meadow

YRS-F1 short segments (Alt 

2,4,5, 6,7); D_654-4-2_a, D_654-

4_a, D_85-2-1-1_a (Alt 2,4,5,6); 

D_654-5 (Alt 5,6)

None YRS-F1 – short route segments would not affect 

turtle habitat, not connected.

D_654-4-2_a, D_654-4_a, D_85-2-1-1_a (Alt 

2,4,5,6); D_654-5 (Alt 5,6) – short spurs t access 

dispersed recreation not connected to pond turtle 

site, no impacts.

Alt 1 short segments not connected to turtle site. 

Headwaters North Fork 

American River

Alt 1 existing unauthorized routes None Alt 1 unauthorized routes may impact turtles at 

one part of watershed,

North Fork of North Fork 

American River-Blue Canyon

Alt 1 existing unauthorized routes None Existing unauthorized routes may impact pond 

turtle site

Willow Creek H293 (Alt 5), D_Y-122_a,b,c (Alt 

2,4,5,6).

None H293 located below pond turtle site, would not 

be impacted. 

D_Y-122_a,b,c – not connected would not affect 

pond turtle site.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 497

Natice Surface, Motorized RCA Route Density 

HUC7s with Suitable Northwestern Pond Turtle Habitat

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Alternatives

Percent HUC7 Watersheds

highest (8.9 - 27.3)

moderately high (6.3 - 8.8)

moderately low (4.3 - 6.2)

lowest (0.2 - 4.2)

RCA Motorized Route Density within Northwestern Pond Turtle 7th Field Watersheds: The 

northwestern pond turtle was identified to occur within nine 7th field watersheds on the Tahoe National 

Forest (Cherokee Creek, Willow Creek, Bullards Bar Reservoir-Bridger Creek, Lower Oregon Creek, 

Middle Yuba River-Indian Creek, Lower Middle Yuba River, Headwaters North Fork American River and 

North Fork of North Fork American River-Blue Canyon). For each of the alternatives, Table 3.03-156 and

Figure 3.03-17 displays the number and percent of 7th field watersheds (HUC7s) with known locations of 

NWPT locations by RCA route density category of highest (8.9-27.3.mi/mi2

), moderately high (6.3-8.8 

mi/mi2), moderately low (14.3-6.2 mi/mi2), and lowest (0.2-4.2 mi/mi2). Alternative 1 poses the greatest 

direct and indirect effects to the NWPT where 2 of 9 (22%) pond turtle HUC7 watersheds are within the 

highest route density category, 3 of 9 (33%) are in moderately high; and 1 of 9 (11%) is in moderately 

low, and 3 of ( (33%) are in lowest.

Figure 3.03-17. Number of Northwestern Pond Turtle 7th Field Watersheds by Motorized Native Surface RCA 

Route Density Category

All the action alternatives would reduce RCA route densities compared to Alternative 1. Under 

Alternative 5, 1 pond turtle HUC7 watersheds remains in the highest and moderately high route density 

categories, none are in moderately low, and 78% (7 of 9) HUC7s within the lowest RCA route density 

category. Alternative 6 would reduce route densities where 1 watershed would be in the moderately high 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

498 – Tahoe National Forest

and moderately low route density categories, and the remaining 7 watersheds would be within the lowest 

category.

The remaining alternatives (Alternatives 2, 3, 4, and 7) improves RCA route densities similarly where 

between 1 (11%) watershed falls in the moderately low route density category and 8 pond turtle HUC7s 

(89%) fall within the lowest route density category. 

Table 3.03-156. Number and Percent of 7th Field Watersheds (HUC7s) with Occupied Northwestern Pond 

Turtle Locations by Route Density Category

Alternatives Highest

(8.9 - 27.3 mi/mi2

)

Moderately High

(6.3 - 8.8)mi/mi2)

Moderately Low

(4.3 - 6.2)mi/mi2)

Lowest

(0.2 - 4.2 mi/mi2)

Alt 1 2 3 1 3

Alt 2 0 0 1 8

Alt 3 0 0 1 8

Alt 4 0 0 1 8

Alt 5 1 1 0 7

Alt 6 0 1 1 7

Alt 7 0 0 1 8

Motorized Route (native surface) Crossing Density within Northwestern Pond Turtle 7th Field 

Watersheds: For each of the alternatives, RCA stream crossing density was assessed by crossing density 

categories of highest (5.1-19.7 crossings/sq. mile), moderately high (3.1-5.0 crossings/sq. mile), 

moderately low (1.8-3.0 crossings/sq. mi.), and lowest (0-1.7 crossing/sq. mi.) within 7th field watersheds 

(HUC7s) with known northwestern pond turtles occurrences. Table 3.03-157 and Figure 3.03-18 displays 

the number of HUC7 watersheds with known northwestern pond turtle observations by crossing density 

categories listed above. Alternative 1 poses the greatest direct impacts to northwestern pond turtle from 

stream crossing densities (crossings/square mile) where pond turtles may be disturbed and/or killed; and 

pond turtle aquatic habitat conditions can be impacted from bank alteration and sediment input associated 

with motorized route crossings. Under Alternative 1, 22% (2 of 9) HUC7 watersheds with known pond 

turtle occurrences are within the highest crossing density category, 45% (4 of 9) in moderately high route 

crossing densities, and 11% (1 of 9) within moderately low, and 22% (2 of 9) within lowest categories. 

The remaining action alternatives reduce the number of stream crossings within Riparian Conservation 

Areas, and thus reduce the potential for direct and indirect impacts to the northwestern pond turtle. 

Alternative 5 would reduce crossing densities the least where 1 of 9 (11%) HUC7 remains in the highest 

stream crossing density category, 3 of 9 (33%) is within the moderately high category, 3 of 9 (33%) is 

within moderately low, and 2 of 9 (22%) HUC7s are within the lowest category. Compared to Alternative 

5, Alternative 6 moves 1 HUC7 from the highest stream crossing density category to the moderately high 

category.

Alternatives 2 and 4 would further reduce stream crossing density where, none of the pond turtle 

HUC7 watersheds are in the highest category (5.1-19.7 crossings/mi2

), 3 are in the moderately high 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 499

Native Surface, Motorized Stream Crossing Density 

HUC7s with Suitable Western Pond Turtle Habitat

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Alternatives

Percent of Watersheds with Suitable NWPT 

Habitat

highest (5.1-19.7)

moderately high (3.1-5.0)

moderately low (1.8-3.0)

lowest (0-1.7)

category (3.1-5.0 crossings/mi2), 4 are in the moderately low category (1.8-3.0 crossings/mi2), and 2 are in 

the lowest category (0-1.7 crossings/mi2).

Alternatives 3 and 7 would similarly reduce the most potential direct and indirect effects where 

HUC7 crossing density categories would be as follows: 0 of 9 HUC7s in the highest, 2 of 9 HUC7s (22%) 

in moderately high, 5 of 9 HUC7s (56%) in moderately low, and 2 of 9 HUC7s (22%) in lowest. Within 

all the action alternatives, unmanaged cross country motorized travel would be prohibited, and over time 

as routes unauthorized to motorized public use are physically revegetated and rehabilitated, the 

northwestern pond turtle and their habitat would benefit in the long term.

Table 3.03-157. Number of 7th Field Watersheds (HUC7s) with Occupied Northwestern Pond Turtle Locations 

by Stream Crossing Density Category of Native Surfaced Routes

Alternatives Highest

(5.1-19.7 crossings/mi2

)

Moderately High

(3.1-5.0 crossings/mi2)

Moderately Low

(1.8-3.0 crossings/mi2)

Lowest

(0-1.7 crossings/mi2)

Alt 1 2 4 1 2 

Alt 2 0 3 4 2

Alt 3 0 2 5 2

Alt 4 0 3 4 2

Alt 5 1 3 3 2

Alt 6 0 4 3 2

Alt 7 0 2 5 2

Figure 3.03-18. Northwestern Pond Turtle 7th Field Watersheds by Motorized Crossing
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

500 – Tahoe National Forest

Cumulative Effects

The geographic boundary for assessing cumulative effects to the northwestern pond turtle is the westside 

of the Tahoe NF below 6,000 feet within lacustrine habitat (ponds and lakes), since this is within habitat 

that is considered suitable on the Tahoe NF. This geographic boundary is sufficiently large to encompass 

historic and potential pond turtle habitat on the Tahoe NF. Any larger boundary could dilute the effects of 

past, present, and future cumulative impacts to this species. The timeframe for assessing cumulative 

impacts in the past includes activities that occurred within approximately the last 20 years. Reasonably 

foreseeable future impacts expand out to approximately 20 years into the future.

Current pond turtle habitat impacts from existing motorized routes has been documented at the Pierce 

wetland area within the South Yuba - Pierce 7th Field watershed on the Yuba River Ranger District where 

vehicles have altered and degraded pond turtle riparian vegetation, soils, and hydrology. This particular 

pond turtle location could be at risk from crushing and mortality and habitat degradation from continued 

motorized vehicle use off of routes.

Grazing has the potential to add to cumulative effects to the northwestern pond turtle. Known pond 

turtle locations occur within one active grazing allotment - Willow Creek. The recently closed Our House 

Allotment also has pond turtle occurrences where grazing impacts would no longer occur in the future. An 

additional 10 allotments has potential pond turtle habitat and could receive cumulative impacts from 

livestock grazing were turtles to be found there.

Alternative 1 would result in the greatest cumulative impacts to current existing cumulative impacts 

where HUC7 watersheds where pond turtles are located, and would have the have the greatest route 

densities and stream crossing densities compared to all the action alternatives. Beneficial impacts to pond 

turtle habitat would occur with all the action alternatives similarly from the reduction in RCA route 

density and stream crossing density. Alternative 5 would benefit the least and Alternative 3 would benefit 

the most. Direct and indirect beneficial effects of the action alternatives would prohibit cross country 

travel on 31 to 47 total crossings and on between 10 to 17 RCA miles within HUC7s 

Non-motorized use (hiking, mountain bicycling, equestrian, etc.) may occur on routes that would be 

prohibited to motorized use. In general, it is expected that impacts from non-motorized use would be less 

than motorized use. Over time, it is expected that these the prohibition of cross country travel, including 

on motorized routes unauthorized to motorized public use would become revegetated and recover through 

active or passive means, and ultimately benefit the northwestern pond turtle in the future.

Summary of Direct, Indirect, and Cumulative Effects of Proposed Actions

Table 3.03-158 summarizes the direct, indirect, and cumulative effects of native surfaced, motorized route 

crossings within NWPT HUC 7 watersheds, from existing motorized routes, motorized route additions, 

and routes unauthorized to motorized public travel from the proposed actions, including wet weather 

seasonal restrictions, changes in class of vehicles, prohibition of cross country travel. See Chapter 3.02,

Watershed Resources: Geology, Soil, Hydrology, for more detailed information and assumptions.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 501

Table 3.03-158. Northwestern Pond Turtle 7th Field Watersheds – Summary of Direct, Indirect, and Cumulative Effect of Proposed Actions as Measured 

by Native Surfaced, Motorized Crossings

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres Habitat 

Prohibited to 

Cross Country 

Travel

0 7,986 7,986 7,986 7,986 7,986 7,986

Crossings closed 

by previous NEPA 

decisions, 

pending 

implementation

1 1 1 1 1 1 1

Unauthorized 

Crossings 

Prohibited to 

Cross Country 

Travel

0 43 46 44 30 39 46

Total Crossings 

Prohibited to 

Cross Country 

Travel

1 44 47 45 31 40 47

Motorized Stream Crossings

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Existing NFTS 

Native Surfaced, 

Motorized Stream 

Crossings 

14 14 14 14 14 14 14

Native Surfaced, 

Motorized 

Crossing 

Additions*

46 3 0 2 16 7 0

Change in Class 

of Vehicles from 

Smooth Surfaced 

to Native Surfaced 

Crossings

0 0 0 0 0 0 0

Native Surfaced 

Crossings from 

Reopened ML 1 

Roads

0 0 0 0 0 0 0
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

502 – Tahoe National Forest

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Net Native 

Surfaced, 

Motorized 

Crossings*

60 17 14 16 30 21 14

Wet Weather 

Seasonal 

Restrictions on all 

Native Surfaced 

Routes

None None None Beneficial - Wet 

Weather 

Restrictions would 

be implemented.

Beneficial - Wet 

Weather 

Restrictions would 

be implemented.

Beneficial - Wet 

Weather 

Restrictions would 

be implemented.

None

Net Direct, 

Indirect, and 

Cumulative Effect 

of Proposed 

Actions

Cumulative adverse 

effects from 

continued 

motorized cross 

country travel on 

7,986 RCA acres, 

including on 46 

native surfaced, 

stream crossings. 

Motorized use 

continues on 60 

native surfaced, 

crossings 

No additional 

protection to NWPT 

habitats from wet 

weather seasonal 

restrictions.

4th most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 7,986 

RCA acres, 

including on 44

native surfaced, 

stream crossings.

17 NFTS crossings 

available for 

motorized use.

No additional 

protection to NWPT 

habitats from wet 

weather seasonal 

restrictions.

3rd most beneficial 

alternative, shared 

with Alternative 7.

Motorized cross 

country travel 

prohibited on 7,986 

RCA acres, 

including on 47

native surfaced, 

stream crossings

14 NFTS crossings 

available for 

motorized use. 

No additional 

protection to NWPT 

habitats from wet 

weather seasonal 

restrictions.

Most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 7,986 

RCA acres, 

including on 45

native surfaced, 

stream crossings 

16 NFTS crossings 

available for 

motorized use. 

Reduced 

sedimentation risk 

to NWPT habitats 

from wet weather 

seasonal 

restrictions.

Least beneficial 

alternative due to 

number of native 

surfaced crossings 

added.

Motorized cross 

country travel 

prohibited on 7,986 

RCA acres, 

including on 31

native surfaced, 

stream crossings

30 NFTS crossings 

available for 

motorized use. 

Reduced 

sedimentation risk 

to NWPT habitats 

from wet weather 

seasonal 

restrictions.

2nd most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 7,986 

RCA acres, 

including on 40

native surfaced, 

stream crossings

21 NFTS crossings 

available for 

motorized use. 

Reduced 

sedimentation risk 

to NWPT habitats 

from wet weather 

seasonal 

restrictions.

3rd most beneficial 

alternative, shared 

with Alternative 3.

Motorized cross 

country travel

prohibited on 7,986 

RCA acres, 

including on 47

native surfaced, 

stream crossings

14 NFTS crossings 

available for 

motorized use. 

No additional 

protection to NWPT 

habitats from wet 

weather seasonal 

restrictions.

*Alternative 1 includes existing native surfaced, unauthorized routes, while all the action alternatives include motorized route additions.

Table 3.03-159 summarizes the direct, indirect, and cumulative effects of native surfaced, motorized RCA route miles within NWPT HUC 7 

watersheds, from existing motorized routes, motorized route additions, and routes unauthorized to motorized public travel from the proposed 

actions, including wet weather seasonal restrictions, changes in class of vehicles, prohibition of cross country travel. See Chapter 3.02, Watershed 

Resources: Geology, Soil, Hydrology, for more detailed information and assumptions.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 503

Table 3.03-159. Northwestern Pond Turtle 7th Field Watersheds – Summary of Direct, Indirect, and Cumulative Effect of Proposed Actions as Measured 

by RCA Motorized Route Miles

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres Habitat Prohibited to 

Cross Country Travel

0 7,986 7,986 7,986 7,986 7,986 7,986

RCA miles closed by previous 

NEPA decisions, pending 

implementation

0.5 0.5 0.5 0.5 0.5 0.5 0.5

Unauthorized RCA Miles 

Prohibited to Cross Country 

Travel

0 15.8 16.6 16.2 9.9 13.4 16.3

Total RCA Miles Prohibited to 

Cross Country Travel

0.5 16.3 17.1 16.7 10.4 13.9 16.8

RCA Miles of Native Surfaced, Motorized Routes

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Existing RCA Miles 5.3 5.3 5.3 5.3 5.3 5.3 5.3

RCA Miles of Route Additions* 16.5 0.8 0 0.4 6.6 3.1 0.2

Change in Class of Vehicles 

Resulting in Maintenance 

Changed from Smooth 

Surfaced to Native Surfaced 

Motorized Route miles

0 0 0 0 0 0 0

Net NFTS Native Surfaced, 

Motorized RCA Miles*

21.8 6.2 5.3 5.7 11.9 8.4 5.5

Wet Weather Seasonal 

Restrictions on all Native 

Surfaced Routes

None None None Beneficial - Beneficial - Wet 

Weather 

Restrictions 

would be 

implemented

Beneficial - Wet 

Weather 

Restrictions 

would be 

implemented

None
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

504 – Tahoe National Forest

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Net Direct, Indirect, and 

Cumulative Effect of Proposed 

Actions

Cumulative 

adverse effects 

from continued 

motorized cross 

country travel on 

7,986 RCA acres, 

including on 16.5 

RCA miles of 

unauthorized 

routes . 

Motorized use 

continues on 21.8

RCA miles.

No additional 

protection to 

NWPT habitats 

from wet weather 

seasonal 

restrictions.

4th most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

7,986 RCA acres, 

including on 16.3 

RCA miles of 

unauthorized 

routes. 

NFTS motorized 

use available on 

6.2 RCA miles. 

No additional 

protection to 

NWPT habitats 

from wet weather 

seasonal 

restrictions.

3rd most beneficial 

alternative, 

shared with 

Alternative 7.

Motorized cross 

country travel 

prohibited on 

7,986 RCA acres, 

including on 17.1 

RCA miles of 

unauthorized 

routes. 

NFTS motorized 

use available on 

5.3 RCA miles. 

No additional 

protection to 

NWPT habitats 

from wet weather 

seasonal 

restrictions.

Most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

7,986 RCA acres, 

including on 16.7 

RCA miles of 

unauthorized 

routes. 

NFTS motorized 

use available on 

5.7 RCA miles. 

Reduced 

sedimentation risk

to NWPT habitats 

from wet weather 

seasonal 

restrictions.

Least beneficial 

alternative due to 

number of native 

surfaced 

crossings added.

Motorized cross 

country travel 

prohibited on 

7,986 RCA acres, 

including on 10.4 

RCA miles of 

unauthorized 

routes . 

NFTS motorized 

use available on 

11.9 RCA miles.

Reduced 

sedimentation risk 

to NWPT habitats 

from wet weather 

seasonal 

restrictions.

2nd most 

beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

7,986 RCA acres, 

including on 13.9 

RCA miles of 

unauthorized 

routes.

NFTS motorized 

use available on 

8.4 RCA miles. 

Reduced 

sedimentation risk 

to NWPT habitats 

from wet weather 

seasonal 

restrictions.

3rd most beneficial 

alternative, 

shared with 

Alternative 3.

Motorized cross 

country travel 

prohibited on

7,986 RCA acres, 

including on 16.8 

RCA miles of 

unauthorized 

routes.

NFTS motorized 

use available on 

5.5 RCA miles.

No additional 

protection to 

NWPT habitats 

from wet weather 

seasonal 

restrictions.

*Alternative 1 includes existing native surfaced, unauthorized routes, while all the action alternatives include motorized route additions.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 505

Sensitive Aquatic Mollusks 

This section will also address two Sensitive aquatic mollusk species currently designated as Sensitive by 

the Regional Forester, the Great Basin ramshorn snail and the California floater. 

Great Basin Ramshorn Snail: Affected Environment

The Great Basin ramshorn snail (GBRS) is listed as Sensitive on the Region 5 Forester’s Sensitive 

Species List (USDA Forest Service 1998). The Great Basin ramshorn snail occurs in a highly restrictive 

distribution but is locally abundant. Historically, the Great Basin ramshorn snail occurred within the lakes 

and larger, slow streams in and around the northern Great Basin. In California the snail was known to 

occur in six local drainages in which the species probably survives in four of these drainages.

The Great Basin ramshorn snail occurs in larger lakes and slow rivers including larger spring sources 

and spring-fed creeks. These snails characteristically burrow in soft mud and may be invisible even when 

abundant (Taylor 1981). The Great Basin ramshorn snail can occur with Pisidium ultramontanum, Lanx 

klamathensis, or several other endemic mollusks (Frest and Johannes 1993). It also occurs with Juga 

acutifilosa and Fluminicola seminalis. Habitat requirements include cold highly oxygenated water, muddy 

substrate, and slow stream flow. Springs are preferred, but the snail will use river margins. Soft sediments 

are preferred. Threats to snails have been attributed to water diversions and water pollution. Mitigations 

for fish species, such as adding spawning gravels, may harm this species by smothering soft mud habitats.

Historically, the GBRS has been observed in the Truckee River directly downstream of Lake Tahoe, 

on the Lake Tahoe Basin Management Unit. Currently, this snail has not been sighted or surveyed for on 

the Tahoe National Forest. Suitable habitat occurs within slow segments of the Truckee and Little Truckee 

Rivers and their tributaries.

Road and trail-associated risks to this species are similar to those described for fish and frogs 

described above and include habitat alteration, changes in water flow regime, changes in water quality 

and loss of hosts for development.

Great Basin Ramshorn Snail: Environmental Consequences

Indicators used to Measure Effects 

Cross Country Travel: The prohibition of cross country travel is analyzed for the alternatives to estimate 

the potential benefits and reduction in effects to twelve GBRS 7th field watersheds from motorized cross 

country travel.

Additions to the NFTS (GBRS 7th field watersheds): Measures or indicators of changes in 

sedimentation and water surface shade are assessed by analyzing the number of stream crossings 

additions associated with motorized route additions to the NFTS, and the miles of motorized route 

additions within Riparian Conservation Areas (RCAs) for GBRS 7th field watersheds

Establishment of Open Areas: The establishments of “Open Areas” at Boca, Stampede, and Prosser

reservoirs were evaluated under the section “Effects Common to All Aquatic Species.” The Greenhorn 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

506 – Tahoe National Forest

“Open Area” is not within the geographic range of the GBRS, and therefore, no further analysis is 

warranted.

Change in Class of Vehicles (Changed Maintenance Standards): Changing the class of vehicle on 

a particular route potentially changes the impacts to soil and water resource due to changes in the road 

surface (i.e. from smooth surfaced to rough surfaced) (see Chapter 3.02, Watershed Resources: Geology, 

Soil, and Hydrology). If the route changes from smoothed surfaced to native surfaced (rough surfaced), 

the change in class of vehicle may result in increased sediment and erosion risk to GBRS habitat. The 

change in class of vehicle and associated maintenance downgrades is evaluated for their potential to affect 

selected 7th field watersheds that may have suitable habitat for the GBRS.

Wet Weather Seasonal Closures: Wet weather seasonal closures were evaluated under “Effects 

Common to All Aquatic Species.”

Reopened ML 1 Roads. Reopening of ML 1 roads are analyzed for their potential effects to GBRS 

for the alternatives.

Route Density within Riparian Conservation Areas (RCAs) and Stream Crossing Density within 

RCAs: The GBRS shares the same twelve 7th field watersheds as the tui chub (Alder Creek, Prosser 

Creek, Prosser Creek Reservoir, Middle Truckee River-Lower Prosser Creek, Little Truckee River-Saddle 

Meadow, Lower Sagehen Creek, Lower Davies, Hoke Valley, Stampede Reservoir, Little Truckee River 

Canyon, Russel Valley, and Boca Reservoir). Refer to the Lahontan Lake Tui Chub section for analysis of 

native surfaced route densities within RCAs and stream crossing density. 

Direct and Indirect Effects

The Great Basin ramshorn snail has not been sighted or surveyed for on the Tahoe National Forest. 

Suitable habitat occurs within slow flowing segments of the Truckee and Little Truckee Rivers and 

associated tributaries. Direct effects to the species from the action alternatives are not likely since 

confirmation of the species presence has not been confirmed. The nearest known occurrence of the GBRS 

is within the Truckee River downstream of Lake Tahoe on the Lake Tahoe Basin Management Unit. The 

alternatives will be evaluated for their potential indirect impacts to potential habitat for this species. 

Potential habitat for this species occurs within twelve 7th Field watersheds on the eastside of the Tahoe NF 

(Alder Creek, Prosser Creek, Prosser Creek Reservoir, Middle Truckee River-Lower Prosser Creek, Little 

Truckee River-Saddle Meadow, Lower Sagehen Creek, Lower Davies, Hoke Valley, Stampede Reservoir, 

Little Truckee River Canyon, Russel Valley, and Boca Reservoir).

Cross Country Travel. Table 3.03-160 shows that under Alternative 1, no action, motorized cross 

country travel would continue on 12,359 Riparian Conservation Areas (RCAs) acres within GBRS HUC7 

watersheds, where the potential for adversely affecting GBRS habitat could occur by increasing 

sedimentation and altering streamside vegetation. Under the action alternatives, the prohibition of cross 

country travel results in prohibiting motorized use on 12,359 RCA acres, including 22.7 to 26.7 RCA 

miles and from 28 to 35 native surfaced, motorized crossings (Alternative 5 prohibits the least, 

Alternative 3 prohibits the most). Cross country travel prohibitions would likely reduce the potential for 

sedimentation and alteration of streamside vegetation, and therefore benefit GBRS habitat.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 507

Table 3.03-160. Cross Country Travel within Twelve GBRS 7th Field Watersheds

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Acres cross country prohibited 0 12,359 12,359 12,359 12,359 12,359 12,359

Crossings prohibited to cross country travel 0 31 35 34 30 28 32

RCA miles prohibited to cross country travel 0.6 24.7 26.7 26.2 22.7 23.5 25.9

Additions to the NFTS – Stream Crossings and RCA Miles

Number of Native Surfaced, Motorized Stream Crossing Additions within Twelve GBRS 7th Field 

Watersheds. The number of native surfaced, motorized stream crossings, proposed for addition to the 

NFTS, are assessed for the alternatives, and provides a useful way to compare potential changes in 

sediment delivery within GBRS HUC7 watersheds. Alternative 1 poses the greatest risk of increased 

sedimentation where 35 native surfaced, stream crossings are associated with the continuance of cross 

country travel on existing unauthorized motorized routes (Table 3.03-161). In increasing order, 

Alternatives 4, 2, 7, 6, and 5 would result in the addition of 1 to 7 native surfaced, motorized route 

crossings. Alternative 3 does not result in additional native surfaced, motorized stream crossings within 

the twelve GBRS HUC7 watersheds, and therefore sedimentation or streamside vegetation would not be 

affected.

Table 3.03-161. Great Basin Ramshorn Snail HUC7 Watersheds - Number of Native Surfaced, Stream 

Crossings Associated with Motorized Route Additions to the NFTS

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Motorized Stream crossings associated with 

proposed motorized route additions to NFTS 

(negative impact)

35 2 0 1 5 7 3

*Alternative 1 includes motorized stream crossings that would remain with the continuance of cross country travel on existing

unauthorized routes, while all the action alternatives include motorized crossing additions.

RCA Miles of Proposed Additions to the NFTS within GBRS 7th Field Watersheds. The miles of 

proposed motorized route additions to the NFTS within RCAs were assessed for the alternatives, and 

provide additional information to assess the potential for off-site sediment delivery into GBRS habitats at 

the HUC7 level. Alternative 1 poses the greatest risk to increased sedimentation potential from 26 RCA 

miles of motorized routes unauthorized for motorized use that would remain due to not prohibiting cross 

country travel (Table 3.03-162). Similar to stream crossing numbers, Alternatives 2, 4, 5, 6, and 7 propose 

to add between 0.5 and 3.2 RCA miles (Alternative 4 adds the least, Alternative 5 adds the most) of 

motorized routes. Alternative 3 does not add motorized routes to the NFTS, and therefore changes to 

sedimentation or streamside vegetation would not occur within any GBRS HUC7 watershed.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

508 – Tahoe National Forest

Table 3.03-162. Miles of Proposed Motorized Route Additions within twelve GBRS HUC7 Watersheds

Alt 1* Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Miles of proposed motorized route additions within 

RCAs (negative impact)

26.1 2.0 0 0.5 4.0 3.2 0.9

*Alternative 1 includes motorized stream crossings that would remain with the continuance of cross country travel on existing 

unauthorized routes, while all the action alternatives include motorized crossing additions.

Change in Class of Vehicles. For each of the alternatives, Table 3.03-163 displays the effects of 

proposed changes in class of vehicles and the associated maintenance downgrades that have to potential 

to increase the risk of delivering sedimentation and erosion to GBRS HUC7 watersheds. Alternatives 2, 5, 

and 6 result in changed road maintenance resulting in changes from smooth surfaced roads to rough 

surfaced roads. This change in road surface type has a higher potential to result in increased 

sedimentation to GBRS habitat on 7 stream crossings and 2.3 miles of native surfaced, motorized routes.

Table 3.03-163. Great Basin Ramshorn Snail (12 HUC7s) –Change in Class of Vehicles as Measured by 

changes Native Surfaced, Motorized Crossings and Motorized Route Miles

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Number of Native Surfaced Crossings where changed 

maintenance standards result in smooth surfaced to 

native surfaced crossings

0 7 0 0 7 7 0

RCA Motorized Route Miles where changed 

maintenance standards result in smooth surfaced to 

native surfaced crossings

0 2.3 0 0 2.3 2.3 0

Reopened ML 1 Roads. No ML 1 roads are proposed within RCAs of GBRS habitats, and therefore 

would not affect GBRS or habitat under any of the alternatives.

Cumulative Effects

Cumulative Effects Boundary in Space and Time

The geographic boundary for assessing cumulative effects to the Great Basin ramshorn snail on the Tahoe 

NF within the twelve watersheds that may potentially indirectly impact suitable habitat for the species. 

Suitable habitat for this species occurs within slow flowing segments of the Truckee and Little Truckee 

Rivers and associated tributaries on the eastside of the Forest. This cumulative effects boundary is 

sufficiently large to assess all past, present, and future cumulative effects to suitable habitat for the 

ramshorn snail. Any larger boundary could dilute the effects of past, present, and future cumulative 

impacts to this species. The timeframe for assessing cumulative impacts in the past includes activities that 

occurred within the last 50 to 100 years. Reasonably foreseeable future impacts expand out to 

approximately 25 years into the future.

Cumulative Effects of Past, Present, and Reasonably Foreseeable Actions

Historically, the Great Basin ramshorn snail has been observed in the Truckee River directly downstream 

of Lake Tahoe, on the Lake Tahoe Basin Management Unit. The current knowledge of the species 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 509

distribution within the Great Basin is limited in scope. Potential past cumulative effects to this species 

includes habitat degradations from water diversions, reduced water quality, urbanization, livestock 

grazing, recreational activities, and others. Relatively little is known about the life history of this species 

to adequately and effectively address cumulative effects to this species without a lot of speculation. 

Therefore, there is a great deal of uncertainty surrounding the past cumulative effects to this species from 

these activities.

Under Alternative 1, cumulative effects from unauthorized motorized routes would be greatest where 

HUC7 watersheds with potential ramshorn snail habitat would have the highest RCA route densities and 

the highest route crossing densities. The indirect impacts of potential sediment delivery from existing 

motorized routes unauthorized to motorized public use in Alternative 1 would add considerable 

cumulative impacts to potential ramshorn snail habitat where 83% (10 of 12) HUC7 watersheds route 

densities within the highest route density category. Alternative 1 would have the highest stream crossing 

densities compared to all the action alternatives. The remaining alternatives improve both route density 

within Riparian Conservation Areas and stream crossing densities with Alternative 5 reducing the least 

and Alternatives 3, 4, and 7 reducing the most.

For all the action alternatives, future unmanaged cross country motorized travel would be prohibited. 

In addition, prohibition of cross country travel, including on the majority of existing routes unauthorized 

to motorized public use, would likely benefit suitable ramshorn snail habitat in the long-term once these 

routes are rehabilitated through obliteration or other means. Non-motorized use (hiking, mountain 

bicycling, equestrian, etc.) may occur on these routes that would be prohibited to motorized use. In 

general, it is expected that impacts from non-motorized use would be less than motorized use. Over time, 

it is expected that these routes would become revegetated and recover through active or passive means, 

and ultimately benefit habitat for the Great Basin ramshorn snail in the future.

Summary of Direct, Indirect, and Cumulative Effects of Proposed Actions

Table 3.03-164 summarizes the direct, indirect, and cumulative effects of native surfaced, motorized route 

crossings within Great Basin ramshorn snail HUC 7 watersheds, from existing motorized routes, 

motorized route additions, and routes unauthorized to motorized public travel from the proposed actions, 

including wet weather seasonal restrictions, changes in class of vehicles, prohibition of cross country 

travel. See Chapter 3.02, Watershed Resources: Geology, Soil, Hydrology, for more detailed information 

and assumptions.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

510 – Tahoe National Forest

Table 3.03-164. Great Basin Ramshorn Snail 7th Field Watersheds – Summary of Direct, Indirect, and Cumulative Effect of Proposed Actions as 

Measured by Native Surfaced, Motorized Crossings

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Cross Country Travel

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Acres Cross Country 

Travel Prohibited

0 12,359 12,359 12,359 12,359 12,359 12,359

Crossings Prohibited 

to Cross Country 

Travel

0 31 35 34 30 28 32

RCA Miles Prohibited 

to Cross Country 

Travel

0.6 24.7 26.7 26.2 22.7 23.5 25.9

Native Surfaced, Motorized Routes

Trend of Effect Negative Beneficial Beneficial Beneficial Beneficial Beneficial Beneficial

Existing Stream 

Crossings 

82 82 82 82 82 82 82

Native Surfaced, 

Motorized Crossing 

Additions*

35 2 0 1 5 7 3

Change in Class of 

Vehicles Resulting in 

Smooth Surfaced to 

Native Surfaced 

Crossings

0 7 0 0 7 7 0

Net Native Surfaced, 

Motorized Crossings

117 91 82 83 94 96 85

Wet Weather 

Seasonal 

Restrictions on all 

Native Surfaced 

Routes

None None None Beneficial - Wet 

Weather 

Restrictions would 

be implemented

Beneficial - Wet 

Weather 

Restrictions would 

be implemented

Beneficial - Wet 

Weather 

Restrictions would 

be implemented

None
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 511

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Net Direct, Indirect, 

and Cumulative 

Effect of Proposed 

Actions

Most negative 

alternative.

Motorized cross 

country travel 

continues on 

12,359 RCA acres, 

including on 35 

native surfaced, 

stream crossings. 

117 NFTS total 

crossings would 

receive motorized 

use.

No additional 

protection to 

GBRS habitats 

from wet weather 

seasonal 

restrictions.

6th most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

12,359 RCA acres, 

including on 31 

native surfaced, 

stream crossings.

91 NFTS crossings 

available for 

motorized use.

No additional 

protection to 

GBRS habitats 

from wet weather 

seasonal 

restrictions.

4th most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

12,359 RCA acres, 

including on 35 

native surfaced, 

stream crossings.

82 NFTS crossings 

available for 

motorized use. 

No additional 

protection to 

GBRS habitats 

from wet weather 

seasonal 

restrictions.

Most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

12,359 RCA acres, 

including on 34 

native surfaced, 

stream crossings.

83 NFTS crossings 

available for 

motorized use. 

Reduced 

sedimentation risk 

to GBRS habitats 

from wet weather 

seasonal 

restrictions.

2nd most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

12,359 RCA acres, 

including on 30 

native surfaced, 

stream crossings.

94 NFTS crossings 

available for 

motorized use. 

Reduced 

sedimentation risk 

to GBRS habitats 

from wet weather 

seasonal 

restrictions.

3rd most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

12,359 RCA acres, 

including on 28 

native surfaced, 

stream crossings.

96 NFTS crossings 

available for 

motorized use. 

Reduced 

sedimentation risk 

to GBRS habitats 

from wet weather 

seasonal 

restrictions.

5th most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

12,359 RCA acres, 

including on 32 

native surfaced, 

stream crossings.

85 NFTS crossings 

available for 

motorized use. 

No additional 

protection to 

GBRS habitats 

from wet weather 

seasonal 

restrictions.

*Alternative 1 includes existing native surfaced, crossings unauthorized to motorized use, while all the action alternatives include motorized crossing additions.

Table 3.03-165 summarizes the direct, indirect, and cumulative effects of native surfaced, motorized RCA route miles within GBRS HUC 7 

watersheds, from existing motorized routes, motorized route additions, and routes unauthorized to motorized public travel from the proposed 

actions, including wet weather seasonal restrictions, changes in class of vehicles, prohibition of cross country travel. See Chapter 3.02, Watershed 

Resources: Geology, Soil, Hydrology, for more detailed information and assumptions.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

512 – Tahoe National Forest

Table 3.03-165. Great Basin Ramshorn Snail 7th Field Watersheds – Summary of Direct, Indirect, and Cumulative Effect of Proposed Actions as 

Measured by RCA Motorized Route Miles

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Acres Cross Country 

Travel Prohibited

0 9,770 12,359 12,359 12,359 12,115 12,359

RCA Route Miles 

Unauthorized to Motorized 

Use Where Cross Country 

Travel is Prohibited

0.6 24.7 26.7 26.2 22.8 23.5 25.9

Existing NFTS RCA Miles 

of Native Surfaced, 

Motorized Routes 

31.3 31.3 31.3 31.3 31.3 31.3 31.3

RCA Miles of Native 

Surfaced, Motorized Route 

Additions*

26.1 2.0 0 0.5 4.0 3.2 0.9

Establishment of Open 

Areas

Cross country 

travel continued 

around Boca, 

Stampede, 

Prosser and 

Greenhorn

2,589 0 0 0 244 0

Change in Class of 

Vehicles Resulting in 

Maintenance Changed 

from Smooth Surfaced to 

Native Surfaced Motorized 

miles

0 2.3 0 0 2.3 2.3 0

Net NFTS Native Surfaced, 

Motorized RCA Miles

58 35.6 31.3 31.8 37.6 36.8 32.2

Wet Weather Seasonal 

Restrictions on all Native 

Surfaced Routes

None None None Beneficial - Wet 

Weather 

Restrictions would 

be implemented

Beneficial - Wet 

Weather 

Restrictions would 

be implemented

Beneficial - Wet 

Weather 

Restrictions would 

be implemented

None
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 513

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Net Direct, Indirect, and 

Cumulative Effect of 

Proposed Actions

Most negative 

alternative –

adverse 

cumulative 

impacts.

Motorized cross 

country travel 

continues on 

12,359 RCA 

acres, including on 

26 RCA miles of 

unauthorized 

routes. 

No additional 

protection to 

GBRS habitats 

from wet weather 

seasonal 

restrictions.

6th most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

9,770 RCA acres.

NFTS motorized 

use available on 

35.6 RCA miles. 

No additional 

protection to 

GBRS habitats 

from wet weather 

seasonal 

restrictions.

4th most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

12,359 RCA 

acres. 

NFTS motorized 

use available on 

31.3 RCA miles. 

No additional 

protection to 

GBRS habitats 

from wet weather 

seasonal 

restrictions.

Most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

12,359 RCA acres 

NFTS motorized 

use available on 

31.8 RCA miles. 

Reduced 

sedimentation risk 

to GBRS habitats 

from wet weather 

seasonal 

restrictions.

2nd most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

12,359 RCA 

acres.

NFTS motorized 

use available on 

37.6 RCA miles.

Reduced 

sedimentation risk 

to GBRS habitats 

from wet weather 

seasonal 

restrictions.

3rd most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

12,115 RCA 

acres. 

NFTS motorized 

use available on 

36.8 RCA miles. 

Reduced 

sedimentation risk 

to GBRS habitats 

from wet weather 

seasonal 

restrictions.

5th most beneficial 

alternative.

Motorized cross 

country travel 

prohibited on 

12,359 RCA 

acres.

NFTS motorized 

use available on 

32.2 RCA miles.

No additional 

protection to 

GBRS habitats 

from wet weather 

seasonal 

restrictions.

*Alternative 1 includes existing unauthorized routes, while all the action alternatives include motorized route additions.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

514 – Tahoe National Forest

California Floater: 

Affected Environment and Environmental Consequences

The California floater (Anodonta californiensis) is listed as a Sensitive Species in Region 5 and 

designated as a “species of special concern” by the State of California. The California floater occurs in 

lakes and slow rivers (Taylor 1981), generally, on soft substrates (mud-sand), in fairly large streams and 

lakes, in relatively slow currents (Frest and Johannes 1995).

The current known distributions in California are the Lassen, Modoc, and Shasta-Trinity National

Forests. This species still survives in Fall and Pit Rivers, Shasta Co. The California floater has been 

reported to occur adjacent to the Tahoe NF, but no occurrences have been documented on NFS lands 

within the boundary of the Tahoe NF. Donner Lake is reported as the locality of an unconfirmed historic 

sighting in a mollusk database created by Drs. Jayne Brim-Box and Jeff Kershner (pers. communication). 

The species has been reported to occur at the following sites in Nevada: 1)Truckee River, 2) Humboldt 

River, Humboldt Basin, Elko, Co. in 1979, 3) Thousand Springs Valley northeast of Wells, Elko Co., Lake 

Bonneville Basin in 1989 (Nevada Natural Heritage Database).

Howard and Cuffey (2003) found that the California floater was almost exclusively found in pools 

with no riffles and very few in runs in the south Fork of the Eel River in Oregon.

Road and trail-associated risks to the California floater are similar to those described for other aquatic 

species described above, and include changes in sedimentation delivery, habitat alteration, changes in 

water flow regime, changes in water quality and loss of hosts for development.

Direct, Indirect and Cumulative Effects

The California floater has not been confirmed to occur on the Tahoe NF, therefore the alternatives would 

not directly or indirectly affect the California Floater. Historically, the California floater was reported 

from Donner Lake within private lands and near Lake Tahoe within the Truckee River. Potentially 

suitable habitat for the floater on the Tahoe NF includes the Truckee River and streams tributary to it. 

Direct, indirect and cumulative effects to potentially suitable habitat of the floater would be similar to 

those addressed for the Great Basin ramshorn snail. See Environmental Consequences for ramshorn snail 

in the previous section.

Compliance with Forest Plan and Other Direction

The Tahoe LRMP, as amended by the SNFPA 2004, provides management direction for riparian and 

aquatic dependent resources. The following management standards and guidelines apply to the TNF 

Travel Management Project for aquatic species and were considered for the analysis of the alternatives.

1. Evaluate new proposed management activities within CARs and RCAs during environmental 

analysis to determine consistency with the riparian conservation objectives (RCOs) at the 

project level and the AMS goals for the landscape. Ensure that appropriate mitigation measures 

are enacted to (1) minimize the risk of activity-related sediment entering aquatic systems and (2) 

minimize impacts to habitat for aquatic- or riparian-dependent plant and animal species 

(Management Standard & Guideline 92).
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

Tahoe National Forest – 515

In the sections above, the alternatives for the Tahoe NF Motorized Travel Management Project 

were analyzed for consistency with the LRMP riparian conservation objectives (See RCO 

analysis). Management design standards and mitigation measures were developed to minimize 

the risk of increasing sediment to aquatic systems and to minimize impacts to habitat for aquatic 

and riparian dependent species. All proposed action alternatives reduce or minimizes adverse 

effects to aquatic systems, particularly through the prohibition of cross country travel within 

close proximity or adjacent to aquatic ecosystems.

2. Maintain and restore the hydrologic connectivity of streams, meadows, wetlands, and other 

special aquatic features by identifying roads and trails that intercept, divert, or disrupt natural 

surface and subsurface water flow paths. Implement corrective actions where necessary to 

restore connectivity (RCO#2, Management Standard & Guideline 100).

Under the action alternatives, native surfaced, motorized route and area additions and their 

associated stream crossings were evaluated for their hydrologic condition. Corrective actions and 

mitigation measures were developed when it was deemed necessary. See Appendix A (Site 

Specific Road, Trail and Open Area Information), Watershed Resources: Geology, Soil, 

Hydrology (Chapter 3.02), and Appendix I (Riparian Conservation Objectives).

3. Ensure that culverts or other stream crossings do not create barriers to upstream or downstream 

passage for aquatic-dependent species. Locate water drafting sites to avoid adverse effects to in 

stream flows and depletion of pool habitat. Where possible, maintain and restore the timing, 

variability, and duration of floodplain inundation and water table elevation in meadows, 

wetlands, and other special aquatic features (RCO#2, Management Standard & Guideline 101).

Proposed stream crossings additions were inventoried and evaluated for their condition. 

Appropriate mitigation measures were developed (See Appendix A, Site Specific Road, Trail and 

Open Area Information).

4. Prior to activities that could adversely affect streams, determine if relevant stream 

characteristics are within the range of natural variability. If characteristics are outside the range 

of natural variability, implement mitigation measures and short-term restoration actions needed 

to prevent further declines or cause an upward trend in conditions. Evaluate required long-term

restoration actions and implement them according to their status among other restoration needs 

(RCO#2, Standard and Guideline 102).

Proposed route additions to the NFTS were inventoried and assessed for their condition. 

Conditions were described and mitigations measures were developed as appropriate. 

5. Identify roads, trails, OHV trails and staging areas, developed recreation sites, dispersed 

campgrounds, special use permits, grazing permits, and day use sites during landscape analysis. 

Identify conditions that degrade water quality or habitat for aquatic and riparian-dependent 

species. At the project level, evaluate and consider actions to ensure consistency with standards 

and guidelines or desired conditions (RCO#3, Management Standard and Guideline 116).
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.03. Terrestrial and Aquatic Species

516 – Tahoe National Forest

For the Tahoe NF Travel Management Project, each proposed route addition was evaluated for 

their potential to degrade water quality or habitat for aquatic and riparian-dependent species. 

Proposed route additions were evaluated for their proximity to aquatic habitats and their 

potential to affect aquatic systems, including water quality, soil condition, hydrologic 

connectivity, and riparian vegetation.

Summary of Effects Analysis across All Alternatives 

The following tables provide a relative ranking of effects by Terrestrial Species and Aquatic and Riparian 

Species. Please refer to the alternative analyses for more detailed descriptions of effects. The score of 7 = 

least impact for biological resource; score of 1 = most impact for biological resource.

Table 3.03-166. Comparison of Effects to Terrestrial Species

Indicators – Terrestrial Species Rankings of Alternatives for Each Indicator

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Density of motorized routes at the watershed level. 1 4 7 6 2 3 5

Acres open to motorized use and Miles of 

unauthorized routes within terrestrial species habitat. 1 2 7 6 3 4 5

Miles of motorized routes at forest-wide scale and 

within the habitat for each species group. 1 4 7 6 2 3 5

Number of sensitive sites for TES species (e.g., 

PACs, nest sites, winter roost areas) within 1⁄4 mile of 

an added route or area.

1 4 7 6 2 3 5

The proportion of a species (or species group’s) 

habitat that is affected by motorized routes. 1 4 7 6 2 3 5

Average for Terrestrial Species 1 3.6 7 6 2.2 3.2 5

Table 3.03-167. Comparison of Effects to Aquatic and Riparian Species

Indicators – Aquatic and Riparian Species Rankings of Alternatives for Each Indicator

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Miles of unauthorized routes within or adjacent to 

TES aquatic/riparian species habitat. 1 3 7 6 2 4 5

Density of high risk motor vehicle routes as a 

measure of habitat effectiveness at the 7th field 

watershed level. 

1 3 7 6 2 4 5

Miles of motor vehicle routes and acres of areas at 

forest-wide scale and within the habitat for each 

species. 

1 3 7 6 2 4 5

The proportion of a species habitat that is affected 

by motor vehicle routes 1 3 7 6 2 4 5

Number hydrologically sensitive areas within 300 ft. 

(RCA width) of an added route or area. 1 4 7 6 2 3 5

Average for Aquatic and Riparian Species 1 3.2 7 6 2 3.8 5
Chapter 3.04 

Fire Fuels 

Management 

Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Tahoe National Forest – 517

3.04. Fire Fuels Management ______________________________

This section focuses on analyses of the alternatives presented in this EIS and how they could affect 

current fire and fuels management on the Tahoe National Forest (TNF).

Affected Environment

Fire Management

Understanding past and present roles of fire in shaping TNF ecosystems is critical for managing fire. Fire, 

once a pervasive force in structuring and rejuvenating TNF ecosystems, is now intensively managed. Fire 

has been an important ecosystem process in the Sierra Nevada for thousands of years. Before the area was 

settled in the 1850s, fires were generally frequent throughout much of the range (Sierra Nevada 

Ecosystem Project 1996).

Because fire was so prevalent in the centuries before extensive Euro-American settlement (presettlement), many common plants exhibit specific fire-adapted traits such as thick bark and fire-simulated 

flowering, sprouting, seed release and/or germination (Chang 1996). In addition, fire affected the 

dynamics of biomass accumulation and nutrient cycling, and generated vegetation mosaics at a variety of 

spatial scales (Chang 1996). Because fire influenced the dynamics of nearly all ecological processes, 

reduction of the influence of fire through the 20th century fire suppression efforts in these ecosystem has 

had widespread (though not yet completely understood) effects.

Current management strategies and those of the immediate past have contributed to Forest conditions 

that encourage high-severity fires. The policy of excluding all wildfires has been successful in generally 

eliminating fires of low to moderate severity as a significant ecological process. However, current 

technology is not capable of eliminating the high-severity fires. Thus, the fires that affect significant 

portions of the landscape, which once varied considerably in severity, are now almost exclusively highseverity, large, stand-replacing fires.

Changes in Fuels

The dramatic reduction in area burned in the 20th century, combined with the effects of forest management 

practices and generally warmer-moister climatic conditions (Graumlich 1993; Stein 1996), has almost 

certainly led to substantial increases in the quantity and changes in arrangement of live and dead fuels.

While data from early 20th century are not available to test this assertion rigorously, it is based on 

comparisons with early conditions inferred from numerous historical accounts, documented fire histories, 

and structures of uncut stands (Kilgore and Sando 1975; Parsons and DeBenedetti 1979; Bonnickson and 

Stone 1982; van Wagtendonk 1985; Biswell 1989; Weatherspoon and others 1992; Chang 1996; Skinner 

and Chang 1996; Weatherspoon and Skinner 1996).

Live and dead fuels have increased along with the development of denser conifer forests. These 

increases in stand density were concentrated mainly in small and medium size classes of shade-tolerant 

and fire sensitive species. Lacking fire, the natural thinning that has occurred has been due to competition 

(primarily water and light), diseases, and insects. The result has been a large increase in the amount and 

continuity of live forest fuels near the forest floor that provide a link between the surface fuels and upper 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.04. Fire Fuels Management

518 – Tahoe National Forest

canopy layers. The lack of fire has allowed dead fuels to accumulate in excess of their presettlement 

levels.

Twentieth Century Fire Regimes in Perspective

The TNF has recorded wildfires since establishment of the Forest Reserves in the early 1900s. The TNF

has also compiled detailed information from fire reports for the period between 1976 and the present.

Conclusions about recent fire regimes come from these two information sources as well as technical 

papers that have analyzed these data.

Twentieth century fire regimes in the TNF are very different from pre-European contact fire regimes.

Intervals between present-day fires are longer, allowing more time for fuels and vegetation to accumulate 

between fires. As a result, fires have more fuel to burn and become more severe. Consequently, fires 

today kill more of the vegetation, and are difficult and dangerous to control.

Table 3.04-1 displays how the number and size of fires on the TNF have changed over time. Most 

fires in the Sierra Nevada are suppressed at a very small size. Less than one percent of the fires that 

started on TNF system lands in the last thirty years exceeded 100 acres. Fire fighting capability and 

efficiency has steadily improved through the century as fire suppression technologies have improved and 

expenditures for fire management have increased. The total number of fires started has declined by more 

than 50 percent. However the total number of acres burned has increased by more the four fold. In 

addition, the number of fires in every size category has increased. From 1992 to 2006 there were four 

fires greater than 5,000 acres compared to only one during the previous 15 years.

Table 3.04-1. TNF Acres burned in by size of fire

Years 1977-1991 1992-2008

Total Fires 2,263 1,248

Total Acres Burned 19,828 110,661

Fires greater than 50 acres 12 15

Fires greater than 100 acres 11 15

Fires greater than 1,000 acres 5 10

Fires greater than 5,000 acres 1 6

Trends in Fire Causes and Sizes and Fire Suppression Capability

Human-caused fires have been declining slowly but steadily over the century, likely as a result of 

increased fire suppression efficiency and improved public education (McKelvey and Busse 1996).

However all of the fires greater than 5,000 acres in the last 15 years were human caused. The number of 

lightning-caused fires has remained relatively constant over the century; however, over the last two 

decades the sizes of lightning-caused fires have increased.

The availability of Forest Service firefighting resources and equipment has remained steady or 

declined over the past decade (Husari and McKelvey 1996). A similar trend has occurred in State 

firefighting agencies in Nevada and California. Additional resources are available through local fire 

departments, but these agencies are primarily dedicated to protecting lives and property in the immediate 
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vicinity of their jurisdictions. Human populations are projected to increase in the Sierra Nevada over the 

next half century (Duane 1996). Refer to Chapter 3.11 for more information on population growth. This 

will result in greater demands on local fire departments to provide fire protection to homes and 

communities during periods of high fire danger. In the future, additional firefighting resources may not be 

available to attack multiple lightning fires, especially during their initial stages.

Relationships between Climate and Fire Sizes and Causes

Based on 2,000-year tree ring records from giant sequoia groves, Swetnam (1993) concluded that fire 

activity has consistently decreased when rainfall has increased. The period from 1937 through 1986, has 

been the third wettest half-century in the past 1,000 or more years; it has been the fourth wettest halfcentury in the last 4,000 years (Stine 1996, Graumlich 1993). These wet conditions may have contributed 

to the success of fire suppression in limiting fire size.

Based on available records for the 20th century, McKelvey and Busse (1994) concluded that not all 

hot, dry years were extreme fire years; however, nearly all of the extreme fire years occurred during hot, 

dry periods. The greatest acreage burned coincides with critically dry years (as defined by the California 

Department of Water Resources) in the San Joaquin and Sacramento River Valleys. One-third of the years 

between 1901 and 1969, were ranked as dry or critically dry in at least one of the river valleys. Almost 

one-half of the years between 1970 and 1998 were ranked as dry or critically dry. Extreme fire years 

occurred during the critically dry years; these years reflect the correlation between lightning-caused fires, 

drought years, episodic events, and acres burned.

Wildland Urban Intermix Zone

The wildland urban intermix zone (WUI) is an area where human habitation is mixed with areas of 

flammable wildland vegetation. It extends out from the edge of developed private land into Federal, 

private, and State jurisdictions. There are currently 3,282.6 miles of roads useable by fire suppression 

equipment in the WUI. The WUI is comprised of two zones: the defense zone and the threat zone.

• The defense zone is the buffer in closest proximity to communities, areas with higher densities of 

residences, commercial buildings, and/or administrative sites with facilities. Defense zones 

generally extend roughly 1⁄4 mile out from these areas.

• Threat zones generally extend approximately 11⁄4 miles out from the defense zone boundary; 

however, actual extents of threat zones are based on fire history, local fuel conditions, weather, 

topography, existing and proposed fuel treatments, and natural barriers to fire. 

Environmental Consequences

Weather, topography, and fuels influence the behavior of fires. Motor vehicle access into an area can lead 

to an increased risk of a wildfire being started by humans. Wildfires can be started by the vehicles 

themselves; i.e. sparks from exhaust or hot pieces of metal such as exhaust pipes coming into contact with 

vegetation. In addition human activities in the back country such as camping and hunting can also lead to 

an increased risk of wildfires starting. Motor vehicle use provides access to larger areas for these 

activities and hence a larger area for potential risk of human caused fires.
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520 – Tahoe National Forest

Road access into an area is also a benefit for fire suppression. Road access allows for a more rapid 

initial attack by suppression forces increasing the chance that a wildfire may be stopped at a smaller size.

In addition to quicker access, roads can also allow heavier equipment such as fire engines and bull dozers 

to reach the fire and thus stop the fires at a smaller size. Changes in fuels alter fire behavior and also 

change how fires affect ecosystem components and processes.

Measures or Factors Used to Assess Environmental Consequences

The alternatives can be compared in terms of; 1) how they increase the risk of a wildfire being started by 

humans based the level of access by motorized vehicles and the 2) amount of roads accessible allowing

for a more rapid initial attack by suppression forces with heavier equipment such as fire engines and bull 

dozers.

Risk of Human Caused Wildfire

Although the amount of human caused fires has been decreasing over time, motor vehicle access into an 

area can lead to an increased risk of a wildfire being started by humans. Wildfires can be started by the 

vehicles themselves; i.e. sparks from exhaust or hot pieces of metal such as exhaust pipes coming into 

contact with vegetation. In addition human activities in the back country such as camping and hunting can 

also lead to an increased risk of wildfires starting. Motor vehicle use provides access to larger areas for 

these activities and hence a larger area for potential risk of human caused fires. To assess the changes in 

potential risk the density of open routes accessible by the public was used a potential indicator. Table 

3.04-2 displays the categories used to assess this risk.

Table 3.04-2. Risk Assessment Categories Used For Human Caused Fire

Density of Roads and Trails Open for 

Motor Vehicles by Watershed

Degree of Potential Risk

0 Miles/Square Mile Lowest Risk

0-2 Miles/Square Mile Lower Risk

2-4 Miles/Square Mile Moderate Risk

4-6 Miles/Square Mile Higher Risk

6 Plus Miles/Square Mile Highest Risk

Table 3.04-3 displays the level risk of human caused wildfire by alternative. The greatest level of risk 

is associated with Alternative 1, the No Action Alternative. All of the action alternatives reduce the level 

of risk. Of the action alternatives, the least reduction in risk is associated with Alternative 5. Alternatives 

2, 3, 4, 6 and 7 all have similar reductions in risk of human caused wildfire.
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Table 3.04-3. Changes in Risk of Human Caused Wildfire by Alternative

Risk of Human Caused Wildfire Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Motorized 

Route Density

(Percent of 

Forest Total)

Lowest Risk (0 Miles/Square Mile) .6% .6% .6% .6% .6% .6% .6%

Lower Risk (0-2 Miles/Square Mile) 17.2% 26.6% 27.7% 26.6% 25.0% 27.2% 26.6%

Moderate Risk (2-4 Miles/Square 

Mile)

44.0% 57.7% 56.6% 57.7% 58.2% 57.0% 57.7%

Higher Risk (4-6 Miles/Square Mile) 31.4% 11.5% 11.9% 11.5% 12.6% 11.5% 11.5%

Highest Risk (>6 Miles/Square Mile) 6.9% 3.5% 3.1% 3.5% 3.6% 3.5% 3.5%

Access by Suppression Forces

Road access into an area is also a benefit for fire suppression. Road access allows for a more rapid initial 

attack by suppression forces increasing the chance that a wildfire may be stopped at a smaller size. In 

addition to quicker access, roads can also allow heavier equipment such as fire engines and bull dozers to 

reach the fire and thus stop the fires at a smaller size.

Access by these vehicles is particularly important in the wildland urban intermix zone (WUI). The 

wildland urban intermix zone is an area where human habitation is mixed with areas of flammable 

wildland vegetation. It extends out from the edge of developed private land into Federal, private, and 

State jurisdictions. 

Table 3.04-4 displays the miles of roads useable by heavier equipment such as fire engines and bull 

dozers to reach the fire and thus stop the fires at a smaller size within the wildland urban intermix zone 

(WUI) as well as within the total forest.

Table 3.04-4. Access for fire suppression equipment by alternative

Access for Fire Suppression Equipment Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Roads useable by fire 

suppression equipment 

(miles)

Wildland urban 

intermix zone (WUI) 3,282.6 2501.1 2499.2 2500.3 2523.2 2503.8 2499.2

Forest Total 6,450.6 4,757.3 4,752.3 4,756.0 4,836.7 4,768.1 4,753.3

The greatest level of access is associated with Alternative 1, the No Action Alternative. All of the 

action alternatives reduce the level of access and all similar reductions in access to allow heavier 

equipment such as fire engines and bull dozers to reach the fire and thus stop the fires at a smaller size.

Summary of Effects Analysis across All Alternatives

The following table summarizes the effects analysis for fire and fuels by ranking each alternative 

regarding how well it provides for each of the indicators. The following rankings were used: A score of 7

indicates the alternative has the least impact for fire and fuels related to the indicator. A score of 1 

indicates the alternative has the greatest adverse impact to fire and fuels. This information is to be used to 

fill out the alternatives summary at the end of Chapter 2 of the EIS.
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Table 3.04-5. Comparison of Effects to Fire and Fuels

Indicator Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Changes in Risk of Human Caused Wildfire by 

Alternative

7 5 1 3 6 2 4

Access for Fire Suppression Equipment by 

Alternative

1 4 7 5 2 3 6

Average 4 4.5 4 4 4 2.5 5
Chapter 3.05 

Cultural Resources 

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Tahoe National Forest – 523

3.05. Cultural Resources _________________________________

Introduction

The Congress in 1966 declared as National policy that the Federal government will “administer federally 

owned, administered, or controlled prehistoric and historic resources in a spirit of stewardship for the 

inspiration and benefit of present and future generations” [National Historic Preservation Act (NHPA) (16 

U.S.C. 470-1(3)]. This policy was made more explicit when the National Historic Preservation Act was 

amended in 1980 and Section 110 was added to expand and underscore Federal agency responsibility for 

identifying and protecting historic properties and avoiding unnecessary damage to them. Many historic 

properties are fragile and once damaged or destroyed cannot be repaired or replaced. Section 106 of the 

NHPA compels Federal agencies to take into account the effect of its undertakings on any district, site, 

building, structure, or object that is included in or eligible for inclusion in the National Register of 

Historic Places (36 CFR 60) (Historic Properties). The Travel Management rule requires that the effects 

on cultural resources be considered with the objective of minimizing damage when designating roads, 

trails, and areas for motor vehicle use on National Forest lands (36 CFR 212.55(a), 212.55(b)(1)).

Analysis Framework: Statute, Regulation, Forest Plan

and Other Direction

The Forest Service is directed to identify, evaluate, treat, protect, and manage historic properties by 

several laws. However, the National Historic Preservation Act of 1966, as amended (16 U.S.C. 470 et 

seq.) (NHPA) provides comprehensive direction to federal agencies about their historic preservation 

responsibilities. Executive Order 11593, entitled Protection and Enhancement of the Cultural 

Environment, also includes direction about the identification and consideration of historic properties in 

Federal land management decisions.

The NHPA of 1966 extends the policy of the Historic Sites Act of 1935 (49 Stat. 666; 16 U.S.C. 461-

467) to include resources that are of State and local significance, expands the National Register of 

Historic Places (NRHP), and establishes the Advisory Council on Historic Preservation (ACHP) and State 

Historic Preservation Officers (SHPO). NHPA Section 106 directs all Federal agencies to take into 

account effects of their undertakings (actions, financial support, and authorizations) on properties 

included in or eligible for the National Register. The Advisory Council on Historic Preservation’s 

regulations at 36 CFR 800 implements NHPA Section 106. NHPA Section 110 sets inventory, nomination, 

protection, and preservation responsibilities for Federally-owned historic properties.

The Forest Service’s policy for compliance with Section 106 of the NHPA in travel management, with 

respect to route designation for motor vehicle use, was issued in 2005: USDA Forest Service Policy for 

Section 106 of the NHPA Compliance in Travel Management: Designated Routes for Motor Vehicle Use

(2005). This policy was developed in consultation with the ACHP. It outlines minimal requirements for 

considering possible effects to historic properties that may be associated with designating routes and areas 

as part of a national forest’s transportation system. This policy statement recognizes the use of 

programmatic agreements for compliance with Section 106 of the NHPA.
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524 – Tahoe National Forest

Section 106 of the NHPA and the ACHPs implementing regulations, Protection of Historic Properties

(36 CFR Part 800), require that federal agencies take into account the effect of their undertakings on 

historic properties, and that agencies provide the ACHP with an opportunity to comment on those 

undertakings. Programmatic agreements (36 CFR 800.14(b)) provide alternative procedures for 

complying with 36 CFR 800. Region 5 has such an agreement: Programmatic Agreement among the 

U.S.D.A. Forest Service, Pacific Southwest Region, U.S.D.A. Forest Service, Intermountain Region’s 

Humboldt-Toiyabe National Forest, California State Historic Preservation Officer, and Advisory Council 

on Historic Preservation Regarding the Process for Compliance with Section 106 of the National Historic 

Preservation Act for Designating Motor Vehicle Routes and Managing Motorized Recreation on the 

National Forests in California (2006) (Motorized Recreation PA). This agreement defines the Area of 

Potential Effects (APE) (36 CFR 800.4(a)(1)) and includes a strategy outlining the requirements for 

cultural resource inventory, evaluation of historic properties, and effect determinations; it also includes 

protection and resource management measures (protection measures) that may be used where effects may 

occur.

Executive Order 11593: Protection and Enhancement of the Cultural Environment, issued May 13, 

1971, directs Federal agencies to inventory cultural resources under their jurisdiction, to nominate 

Federally owned properties that meet the NRHP criteria to the National Register of Historic Places, to use 

due caution until the inventory and nomination processes are completed, and to assure that Federal plans 

and programs contribute to preservation and enhancement of non-Federally owned properties.

Tahoe National Forest cultural resource management direction and standard and guidelines (S&Gs) 

are located in the Tahoe National Forest Land Resource and Management Plan (1990: V-18). They are:

• Cultural Resource Inventories: Preliminary examination overview and/or R-5 Supplement 

survey of areas to identify the presence or absence of archaeological, historical, or other cultural 

resource properties. Includes preparation and approval of reports. Unit of work is the number of 

survey acres examined.

• Cultural Resource Evaluation: A set of properties will be evaluated by a qualified cultural 

resource specialist to determine the significance of cultural and historical values. Includes 

evaluation of proposed actions on cultural resources and appropriate consultation and preparation 

of EA/EIS reports. Includes nomination and/or determination of eligibility of properties for the 

NRHP. Using best professional judgment, the specialist will apply NRHP significance criteria as 

well as the criteria developed in the cultural resources overview.

• Cultural Resources Protection: Activities and costs related to protection of cultural resources 

properties. Includes physical protection, public contact, signing, or other activities associated with 

protection of properties. Where specific management plans are absent, Class 1 properties and 

frequently vandalized properties will be considered for inclusion within patrol routes. Includes 

review, processing, and administration of cultural resource use permits. Unit is properties. Treat 

all properties as significant until evaluated.

• Cultural Resource Enhancement: Includes analysis and intensive research of cultural resource 

properties to provide qualitative and quantitative background data in order to prepare them for 
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public interpretation or scientific or ethnic use. Improvement of the properties with interpretive

services (IS) and facilities for public use should be reported under IS or other developed 

recreation sites.

Effects Analysis Methodology

Assumptions Specific to Cultural Resources

• Unauthorized, user-created routes and areas have already affected cultural resources within 

route/area prisms. 

• Historic railroad grades and roads being used as authorized routes were built for the purposes of 

travel and continued use of them will cause no effect.

• Under the action alternatives, use will continue at current levels or increase over time on the 

designated system with the prohibition of cross country motorized travel.

• Given identical environmental variables, no measurable difference in potential impacts to cultural 

resources exists between that generated by different vehicle classes (i.e., full-size four-wheel 

drive vehicles, off-road vehicles and motorcycles).

• According to the Motorized Recreation PA, all archaeological and historical sites identified 

within the APE for all alternatives adding facilities to the National Forest’s Transportation System 

(NFTS) are considered historic properties for the purposes of this undertaking, unless they 

already have been determined ineligible in consultation with the SHPO or through other agreed 

on procedures (36 CFR 60.4; 36 CFR 800).

• Changing vehicle class or season of use is not considered an undertaking subject to the NHPA. 

However, opening a road to public vehicle use when it was closed previously due to a resource 

conflict is considered an undertaking.

• Changes to the existing NFTS, when combined with the past, present and foreseeable future 

actions are not expected to cumulatively lead to increased impacts to cultural resources.

• Wheeled over snow use has no measurable potential impact to cultural resources.

Data Sources

• Site-specific cultural resource inventories. The Forest conducted cultural resources field surveys 

for this undertaking throughout 2007–09. The primary objectives of these surveys were to 

identify cultural resources in the APE that may be affected by the undertaking and collect 

information on their current condition.

• Existing information from cultural resource records, historic archives, maps, and GIS spatial 

layers was also used.

Cultural Resources Indicators

• Degree to which the integrity of historic property values are diminished. 

• Number of cultural resources within unauthorized routes at risk from ongoing use.

• Average number of cultural resources per acre at risk if new routes or areas are created.
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Cultural Resources Methodology by Action

1. Direct and indirect effects of the prohibition of cross country motorized vehicle travel

Short-term timeframe: 1 year

Long-term timeframe: 20 years. 

Spatial boundary: Forest scale where motor vehicle use is not already prohibited by law (e.g., 

wilderness).

Indicator(s): Number of cultural resources within unauthorized routes at risk from ongoing use. 

Methodology: GIS analysis to identify: (1) the number of cultural resources at risk within 

existing unauthorized routes (estimate of on-going direct and indirect effects curtailed); and (2) 

the average number of cultural resources per acre that would be protected from any new routes 

created in the future without a prohibition (estimate of indirect effects).

Rationale: Motorized Recreation PA.

2. Direct and indirect effects of adding facilities to the NFTS and establishing “Open Areas”

Short-term timeframe: 1 year

Long-term timeframe: 20 years

Spatial boundary: Location of historic property.

Indicator(s): Degree to which the integrity of historic property values are diminished, related to:

location, design, setting, materials, workmanship, feeling, or association. 

Methodology: Use existing data from cultural resource site atlas, historic archives, maps, site 

record files, and GIS spatial layers, and information obtained from archaeological inventories of 

unauthorized routes, to identify cultural resources in the APE that may have direct or indirect 

effects.

Rationale: Motorized Recreation PA.

3. Direct and indirect effects of changes to the existing NFTS including identifying seasons of 

use and vehicle class and reopening Maintenance Level 1 roads.

Changing vehicle class and/or season of use are not considered an undertaking subject to NHPA 

Section 106 compliance (USDA Forest Service Policy for Section 106 of the NHPA Compliance 

in Travel Management: Designated Routes for Motor Vehicle Use (2005)). Motorized vehicles 

can already use NFTS roads. Allowing or prohibiting non-highway vehicle use will have no 

direct, indirect, or cumulative effect on cultural resources. However, reopening a Maintenance 

Level 1 road that was previously closed due to conflicts with cultural resources is considered an 

undertaking.

Short-term timeframe: 1 year

Long-term timeframe: 20 years

Spatial boundary: Location of historic property.

Indicator(s): Degree to which the integrity of historic property values are diminished, related to:

location, design, setting, materials, workmanship, feeling, or association. 
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Methodology: Use existing data from cultural resource site atlas, historic archives, maps, site 

record files, and GIS spatial layers, and information obtained from archaeological inventories of 

unauthorized routes, to identify cultural resources in the APE that may have direct or indirect 

effects.

Rationale: Motorized Recreation PA.

4. Direct and indirect effects of Amendments to the Forest Plan

Amending the Forest Plan to remove the November 1 to May 1 seasonal closure in the Sugar 

Pine area (Management Area 84 Humbug Sailor) on key winter deer range to improve motorized 

recreation opportunities is not considered an undertaking subject to NHPA Section 106 

compliance (USDA Forest Service Policy for Section 106 of the NHPA Compliance in Travel 

Management: Designated Routes for Motor Vehicle Use (2005)). Motorized vehicles can already 

use NFTS roads. Changing the season of use will have no direct, indirect, or cumulative effect 

on cultural resources.

Short-term timeframe: 1 year

Long-term timeframe: 20 years

Spatial boundary: Location of historic property.

Indicator(s): Degree to which the integrity of historic property values are diminished, related to:

location, design, setting, materials, workmanship, feeling, or association. 

Methodology: Use existing data from cultural resource site atlas, historic archives, maps, site 

record files, and GIS spatial layers, and information obtained from archaeological inventories of 

unauthorized routes, to identify cultural resources in the APE that may have direct or indirect 

effects.

Rationale: Motorized Recreation PA.

5. Cumulative Effects

Short-term timeframe: not applicable; cumulative effects analysis will be done only for the longterm time frame.

Long-term timeframe: 20 years

Spatial boundary: Forest administrative boundary (outside of designated wilderness).

Indicator(s): Degree to which the integrity of historic property values are diminished, related to:

location, design, setting, materials, workmanship, feeling, or association. 

Methodology: Use existing data from cultural resource site atlas, historic archives, maps, site 

record files, and GIS spatial layers, and information obtained from archaeological inventories of 

unauthorized routes, to identify cultural resources in the APE that may have cumulative effects.

Rationale: Motorized Recreation PA.

Prior to the 1974 Forest and Rangeland Renewable Resources Planning Act (RPA), effects to cultural 

resources were not considered during project planning or implementation. Consequently, cumulative 

impacts of varying degrees occurred within the project area from various land management activities 
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528 – Tahoe National Forest

including mining, logging, road construction, recreation development, dam construction, and 

hydroelectric development to name a few. Stochastic effects, such as natural environmental processes and 

unrestricted land uses, have also contributed to effects to cultural resources within the project area. These 

include dispersed recreation, looting and vandalism by the public, unregulated OHV use, illegal mountain 

bike trail construction, mining, previous road and trail construction and existing road and trail conditions, 

wildfires, erosion, and exposure to the elements.

Subsequent to the 1974 RPA, the vast majority of cultural resources were protected using “flag and 

avoid” measures. Unfortunately, this management practice, which is essentially deferred management, has 

resulted in a high number of recorded archaeological sites that have not been evaluated for inclusion into 

the NRHP resulting in the Forest managing hundreds of sites that may be ineligible for inclusion.

All projects listed in the Reasonably Foreseeable Projects and Cumulative Effects (Appendix H) have 

been or will be subject to NHPA Section 106 compliance and potential effects to cultural resources would 

be identified at that time following stipulations in the Programmatic Agreement Among the USDA Forest 

Service, Pacific Southwest Region, California State Historic Preservation Officer, and Advisory Council 

on Historic Preservation Regarding the Identification, Evaluation and Treatment of Historic Properties 

Managed by the National Forests of the Sierra Nevada, California (Sierra PA; USDA 1996) or successor 

agreement(s).

Cultural Resources: Affected Environment

Cultural resources are archaeological, cultural, and historical legacies from our past that are more than 50 

years old. Cultural resource information, combined with environmental data, can illuminate past 

relationships between people and the land. Cultural-ecological relationships, the result of both natural 

processes and approximately 10,000 years of human interaction in the North-Central Sierra Nevada, are 

key topics in this region’s anthropological, archaeological, and historical research.

With over 3,000-recorded sites on Tahoe National Forest System land, the Forest contains a variety of 

prehistoric and historic archaeological sites, buildings, features and objects (Table 3.05-1). Research of 

cultural resources discovered within the Tahoe National Forest (TNF) indicate that people have been 

using the Forest for over 8,000 years with intensification occurring within the last 5,000-4,000 years. By 

5,000 years ago on the Westside of the Forest, permanent villages were established at elevations generally 

below 3,500 feet (snow line). On the Eastside of the Forest, winter villages were located in the lower 

elevation valleys where Reno and Carson City, Nevada, are located. Prior to the crossing of the Sierra 

Nevada by emigrant parties, an extensive trail system was established by Native people for travel and 

trade. Many of these trails became major travel routes into California during the historic era. Two Native 

American ethnographic groups, the Nisenan Maidu and the Washoe, have direct ties to Tahoe National 

Forest System land. To date, no traditional cultural properties (TCP) or sites of religious or cultural 

importance have been identified within the TNF.
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Table 3.05-1. Cultural Resource Sites within the Tahoe National Forest

Type of Site # Sites

Documented Sites 3,228

National Register Listed Properties (included in the figure given above) 7

Sites representing prehistoric and ethnographic land use include seasonal villages, temporary camps, 

toolstone quarries, bedrock mortar milling locations, and petroglyphs. People today favor many of the 

areas preferred by Native people. Resource extraction, grazing, residential development, and recreation 

are common modern activities throughout the Forest.

During the late 1830s and 1840s, trappers and explorers began venturing into California. With the 

discovery of gold in Coloma in 1848 came a massive emigration of gold seekers and settlers into the area 

now encompassed by the TNF. This event had a devastating effect on the local Native American Maidu 

groups through the impacts of displacement, disease, Native food resources elimination, and death. 

Numerous trails and routes were established across the TNF including various branches associated with 

the Overland Emigrant Trail, the Placer County Emigrant Trail, and the Henness Pass Road. These early 

roads accessed different mining communities. Local toll roads and turnpikes, like the Michigan to Last 

Chance Trail, the Enterprise and the Pacific Turnpikes, the Skillman Flat Toll Road, the Galloway Ridge 

Road and the Sierra Turnpike, were constructed to link settlements and transport supplies. The completion 

of the Central Pacific Railroad across the North-Central Sierra Nevada, and the TNF, established this 

route as one of the major transportation corridors into California. Four of California’s original 64 State 

Highways, including the Victory and Lincoln Highways, are within the TNF (State Highways 25, 36, 38 

and 37) as is part of the Tahoe to Ukiah Highway (State Route 20). The Victory and Lincoln Highways 

followed the corridor of the Central Pacific Railroad. This corridor eventually became Highway 40 and 

Interstate 80. These routes have played an important part in changing the environment as the access to the 

Forest allowed for early (i.e., beginning with the 1849 Gold Rush) and extensive development.

Historic mining is only located on the Westside of the Forest. Due to the deeply incised nature of the 

terrain, many of the sites are located in the rugged terrain of the Yuba, Bear, and American Rivers and 

their associated tributaries. This area of California was one of the richest producing gold areas in the 

State. Consequently, hundreds of mines and roads to access the mines were established in the 1850s.

Logging occurred throughout the entire Forest and an extensive network of logging road and railroad 

grades were built to supply lumber and various wood products to support other industries (mining, 

construction, fuel for steam power, and shipping containers). On the Eastside of the Forest, with its open 

Eastside Pine habitat and terrain, logging, ranching, and ice production were primary industries. 

Beginning in the 1890s, railroad based logging extended from the Central Pacific Railroad to the farthest 

reaches of the Forest on the Eastside and eventually linked into the Feather River Canyon railroad line on 

the north end of Sierra Valley. Many of these railroad grades provide the footprint for many roads on the 

Eastside. On the Westside of the forest, large scale commercial logging companies focused on relatively 

easy to log terrain that bordered the Central Pacific Railroad. In the rugged mountainous mining areas of 
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530 – Tahoe National Forest

Downieville and Foresthill, local mills supplied more local needs and markets. Logging has continued 

until recent years as a dominant industry in the TNF.

Historic cultural resources reflect particularly the cultural and economic products of the rapid pace of 

technological achievement in the last two centuries. These more recent resources often reflect industrial 

and technological advances in resource extraction, landscape use, and, later, management by the Forest 

Service and other State and local agencies.

Sites representing historic land use include cabins, roads and trails, bridges, lumber or mining mill 

complexes, town sites, ditches, homesteads, sheep camps, arbor glyphs (tree carvings), railroad grades,

trestles, mining shafts and adits, ground sluicing areas and tailings, Forest Service administrative 

buildings and compounds, along with logging, mining, grazing, and recreation landscapes. Nearly all of 

the historic sites found in the TNF date from ca. 1846 to the present. Historic sites provide many 

opportunities for interpretation and public appreciation.

Existing Conditions

Field surveys were conducted to identify cultural resources in the APE that may be affected by the 

undertaking (i.e., to determine the resources at risk). New sites located were recorded. Existing sites were 

monitored to obtain current condition information. Cultural resources specialists conducted field surveys 

during the field seasons of 2007-2009. Existing archaeological, historic, and ethnographic literature in the 

Forest’s Heritage Program files, Infra database and GIS were reviewed. A cultural resources report 

summarizes the data collected for this proposed undertaking (Tahoe National Forest Cultural Resource 

Report TNF02051/R2007051700062). The report includes a survey summary and site condition 

assessment of the sites associated with routes or areas being considered for addition to the NFTS and

provides the background information for this chapter.

The primary objectives of this project from its inception in 2007 were to identify cultural resources in 

the APE that may be affected by the undertaking (i.e., resources at risk) and collect information on their 

condition. Surveys consisted of pedestrian transects conducted according to methods and standards 

mandated in the Motorized Recreation PA. The Forest has calculated a maximum of 88 miles of 

unauthorized routes (13 miles of roads from Alternative 6 and 75 miles of motorized trails from 

Alternative 5) and 93 miles of Maintenance Level 1 (ML 1) roads (from Alternative 5): the unauthorized 

routes are being analyzed as potential additions to the NFTS while the ML 1 roads are being considered 

for re-opening (Table 3.05-2).

Table 3.05-2. Cultural Resource Survey Miles and Acres within APE*

Item Miles Acres

Unauthorized Routes Previously Surveyed (roads and trails) 55 -

Unauthorized Routes Surveyed for this project (roads and trails) 33 -

ML 1 Roads Previously Surveyed 93

“Open Areas” Surveyed - 400

Total 181 400

*Note: Figures have been rounded.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

Tahoe National Forest – 531

The existing condition of cultural resources in the APE, the resources at risk, provides baseline 

information in assessing the potential effect of adding routes to the NFTS. The first step was determining 

the total number of cultural resources within the APE: 149 cultural resource sites have been identified 

within the APE. Of this total number, 133 are considered resources at risk. Resources at risk are those 

cultural resource sites that are either unevaluated or eligible. Table 3.05-3 includes all cultural resources 

sites regardless of NRHP status where any segment of an unauthorized route transects the boundary of a 

site despite scale or impact or is within 30 meters of a route. There are routes associated with multiple 

sites (e.g. Route D_14 and Site 05175500105). Sites such as this were not double counted in the final 

number; they are identified in Table 3.05-3 with an asterisk (*) and in Table 3.05-4.

The NRHP status of all sites is also reported in Table 3.05-3. All cultural resources sites that have not 

been evaluated for the inclusion in the NRHP are noted as unevaluated. Several sites within the APE have 

been evaluated for inclusion in the NRHP. There are 17 sites within the APE that are ineligible for 

inclusion in the NRHP. These sites are not retained in the remaining tables in this chapter. Four (4) sites 

have been determined to be eligible with one of these listed on the NRHP (FS Site 05175700004); see 

Table 3.05-5 for a summary.

In addition to the procedures in the Motorized Recreation PA addressing potential effects, the integrity 

measures listed in the adverse effect criteria at 36 CFR 800.5(a) were also used to characterize the 

severity of any identified effects:

Criteria of adverse effect: an adverse effect is found when an undertaking may alter, directly or 

indirectly, any of the characteristics of a historic property that qualify the property for inclusion in the 

National Register in a manner that would diminish the integrity of the property's location, design, 

setting, materials, workmanship, feeling, or association.[emphasis added] Consideration shall be given 

to all qualifying characteristics of a historic property, including those that may have been identified 

subsequent to the original evaluation of the property's eligibility for the National Register. Adverse effects 

may include reasonably foreseeable effects caused by the undertaking that may occur later in time, be 

farther removed in distance or be cumulative (36 CFR §800.5(a)).

Different disturbance agents can combine in a variety of ways to create a potential effect to cultural 

resources. The results of field survey and archival review demonstrated a number of potential adverse 

effects to cultural resources should certain routes be added to the NFTS. The analysis documented both 

direct effects of designating specific routes (caused by the action and occur at the same time and place) as 

well as indirect (caused by the action and are later in time or farther removed in distance, but are still 

reasonably foreseeable). Examples of effects identified are summarized in Table 3.05-6.

The project’s effect on the integrity of the 133 unevaluated/eligible at risk cultural resource sites was 

assessed. Available data and monitoring observations were used to determine whether or not the proposed 

addition of any route to the NFTS would diminish the integrity of the property's location, design, setting, 

materials, workmanship, feeling, or association. 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

532 – Tahoe National Forest

Table 3.05-3. Summary of Cultural Resources within the APE

Route ID Site Number Site Type NRHP Status

25-9_p 05175300469 Prehistoric Unevaluated

491-3_1 05175300337 Multicomponent Unevaluated

491-3_2 05175300216 Historic Unevaluated

ARM-5 05175400124 Prehistoric Ineligible

Boca Reservoir “Open Area” 05175700175 Prehistoric Ineligible

Boca Reservoir “Open Area” 05175700241 Historic Ineligible

Boca Reservoir “Open Area” 05175700303 Prehistoric Unevaluated

Boca Reservoir “Open Area” 05175700305 Prehistoric Unevaluated

Boca Reservoir “Open Area” 05175700307 Prehistoric Unevaluated

Boca Reservoir “Open Area” 05175700240/CA-NEV-81* Prehistoric Unevaluated

Boca Reservoir “Open Area” CA-NEV-26 Multicomponent Unevaluated

Boca Reservoir “Open Area” 05175700747 Prehistoric Unevaluated

Boca Reservoir “Open Area” 05175700749 Prehistoric Unevaluated

Boca Reservoir “Open Area” 05175700750 Prehistoric Unevaluated

Boca Reservoir “Open Area” 05175700775 Prehistoric Unevaluated

Boca Reservoir “Open Area” 05175700776 Prehistoric Unevaluated

Boca Reservoir “Open Area” 05175700777 Prehistoric Unevaluated

H11E10 05175300696 Historic Unevaluated

H301-6 05175300176* Historic Unevaluated

H301-6 05175300188* Multicomponent Unevaluated

H3-4-4 05175700148* Prehistoric Unevaluated

H54-9 05175600283 Historic Unevaluated

H54-9 05175600341 Multicomponent Unevaluated

H54-9 05175600317 Prehistoric Unevaluated

H88-44 05175400215 Prehistoric Unevaluated

H889-28 05175700088 Prehistoric Unevaluated

H889-3-18-5 05175700563* Prehistoric Unevaluated

H889-8 05175700395* Multicomponent Unevaluated

H889-8 05175700401 Prehistoric Unevaluated

H894-5-1 05175700240/CA-NEV-81* Prehistoric Unevaluated

N25-1-1 05175300347 Prehistoric Unevaluated

N25-1-1 05175300348 Prehistoric Unevaluated

N25-2 05175300454 Prehistoric Unevaluated

N25-6-1 05175300356 Prehistoric Unevaluated

N25-7 05175300034 Prehistoric Unevaluated

N261-8-15-2 05175700563* Prehistoric Unevaluated

N27-3 05175300514 Historic Unevaluated

N27-5 05175300446 Prehistoric Unevaluated

N39-5 05175300217 Historic Unevaluated

N43-6-2 05175400368 Historic Unevaluated

N860-20-1 05175600426 Prehistoric Unevaluated
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

Tahoe National Forest – 533

Route ID Site Number Site Type NRHP Status

N860-20-1 05175700540* Prehistoric Unevaluated

N886-14-10 05175700577 Historic Unevaluated

N886-1-5 05175700009 Multicomponent Unevaluated

N886-1-5 05175700409 Multicomponent Unevaluated

N886-18-10 05175700447 Prehistoric Unevaluated

N886-18-10 05175700529 Prehistoric Unevaluated

N889-3-30-10 05175700304 Prehistoric Unevaluated

N890-14-5 05175700511 Prehistoric Unevaluated

N96-34-2-6 05175400325 Prehistoric Unevaluated

Prosser Reservoir “Open Area” 05175700460 Prehistoric Ineligible

Prosser Reservoir “Open Area” 05175700609 Multicomponent Unevaluated

Prosser Reservoir “Open Area” 05175700608/CA-NEV-64 Prehistoric Unevaluated

Prosser Reservoir “Open Area” 05175700753 Prehistoric Unevaluated

Prosser Reservoir “Open Area” 05175700754 Prehistoric Unevaluated

Prosser Reservoir “Open Area” 05175700755 Prehistoric Unevaluated

Prosser Reservoir “Open Area” 05175700756* Prehistoric Unevaluated

Prosser Reservoir “Open Area” 05175700757 Prehistoric Unevaluated

Prosser Reservoir “Open Area” 05175700758 Prehistoric Unevaluated

Prosser Reservoir “Open Area” 05175700759 Prehistoric Unevaluated

Prosser Reservoir “Open Area” 05175700760 Prehistoric Unevaluated

Prosser Reservoir “Open Area” 05175700761 Prehistoric Unevaluated

Prosser Reservoir “Open Area” 05175700762 Prehistoric Unevaluated

Stampede Reservoir “Open Area” 05175700535 Prehistoric Unevaluated

Stampede Reservoir “Open Area” 05175700540* Prehistoric Unevaluated

Stampede Reservoir “Open Area” 05175700004/SIE-S44 Prehistoric Eligible and listed 

on the National 

Register of Historic 

Places

Stampede Reservoir “Open Area” 05175700763 Prehistoric Unevaluated

Stampede Reservoir “Open Area” 05175700764 Prehistoric Unevaluated

Stampede Reservoir “Open Area” 05175700765 Prehistoric Unevaluated

Stampede Reservoir “Open Area” 05175700766 Prehistoric Unevaluated

Stampede Reservoir “Open Area” 05175700767 Prehistoric Unevaluated

Stampede Reservoir “Open Area” 05175700768 Historic Unevaluated

Stampede Reservoir “Open Area” 05175700769 Historic Unevaluated

Stampede Reservoir “Open Area” 05175700770 Historic Unevaluated

Stampede Reservoir “Open Area” DWR-S-1 Prehistoric Unevaluated

Stampede Reservoir “Open Area” SIE-11 Prehistoric Unevaluated

Stampede Reservoir “Open Area” SIE-12 Prehistoric Unevaluated

Stampede Reservoir “Open Area” SIE-13 Prehistoric Unevaluated

Stampede Reservoir “Open Area” SIE-14 Prehistoric Unevaluated

Stampede Reservoir “Open Area” SIE-15 Prehistoric Unevaluated

Stampede Reservoir “Open Area” SIE-16 Prehistoric Unevaluated
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

534 – Tahoe National Forest

Route ID Site Number Site Type NRHP Status

Stampede Reservoir “Open Area” SIE-17 Prehistoric Unevaluated

Stampede Reservoir “Open Area” SIE-28 Prehistoric Ineligible

D_25_d 05175300004 Historic Eligible

D_11E03_b 05175300016* Multicomponent Unevaluated

D_11E03_c 05175300016* Multicomponent Unevaluated

D_11E03_d 05175300016* Multicomponent Unevaluated

D_721-2_a 05175300074 Prehistoric Unevaluated

D_12E66_c 05175300156* Multicomponent Unevaluated

D_12E66_d 05175300156* Multicomponent Unevaluated

D_S-301_a 05175300176* Historic Unevaluated

D_S-301_a 05175300188* Multicomponent Unevaluated

D_11E10_a 05175300386* Historic Unevaluated

D_12E66_a 05175300404* Prehistoric Unevaluated

D_12E66_a 05175300561* Prehistoric Unevaluated

D_12E67_d 05175300404* Prehistoric Unevaluated

D_12E67_d 05175300561* Prehistoric Unevaluated

D_S295_a 05175300436* Historic Unevaluated

D_S295_b 05175300436* Historic Unevaluated

D_12E68_a 05175300455 Historic Unevaluated

D_S300_a 05175300595* Historic Unevaluated

D_S300_b 05175300595* Historic Unevaluated

D_738-4_a 05175300883 Historic Unevaluated

D_12E66_b 05175300892 Prehistoric Unevaluated

D_6149-31 05175400008 Historic Unevaluated

D_P88_d 05175400176 Historic Eligible

D_P88_b 05175400312 Historic Unevaluated

D_14_b 05175500105* Prehistoric Unevaluated

D_14_c 05175500105* Prehistoric Unevaluated

D_14_h 05175500105* Prehistoric Unevaluated

D_14_j 05175500105* Prehistoric Unevaluated

D_14-4 05175500105* Prehistoric Unevaluated

D_18-19_a 05175500344 Prehistoric Unevaluated

D_738-4_f 05175500363* Multicomponent Unevaluated

D_738-4_g 05175500363* Multicomponent Unevaluated

D_738-4_e 05175500364 Multicomponent Unevaluated

D_SIE-855_a 05175600016 Prehistoric Ineligible

D_5_b 05175600018 Historic Unevaluated

D_16TH19-1 05175600119 Historic Unevaluated

D_7-10 05175600164 Historic Unevaluated

D_860-42 05175600202 Historic Unevaluated

D_SIE-0560_c 05175600249 Historic Ineligible

D_S450 05175600338 Prehistoric Unevaluated
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

Tahoe National Forest – 535

Route ID Site Number Site Type NRHP Status

D_5_a 05175600394 Historic Unevaluated

D_860-25 05175600421 Prehistoric Unevaluated

D_SV-M1 05175600431 Multicomponent Unevaluated

D_560-20_b 05175600442 Historic Eligible

D_860-40 05175600449 Historic Ineligible

D_03-4_a 05175700148* Prehistoric Unevaluated

D_270-8_b 05175700358* Multicomponent Unevaluated

D_270-8_c 05175700358* Multicomponent Unevaluated

D_886-10_a 05175700379* Prehistoric Unevaluated

D_886-18_a 05175700379* Prehistoric Unevaluated

D_886-18_b 05175700379* Prehistoric Unevaluated

D_S860_a 05175700620 Multicomponent Unevaluated

D_787-19 05175700756* Prehistoric Unevaluated

D_450-101_a 05175700779 Historic Unevaluated

D_72_d 05175700125 Historic Ineligible

D_860-5_b 05175700354* Prehistoric Ineligible

D_860-5_h 05175700097/05175700101* Prehistoric Ineligible

D_860-5_i 05175700096* Historic Unevaluated

D_N886_18C 05175700778 Prehistoric Unevaluated

D_NEV-3013_b 05175700264 Historic Ineligible

SV-P14 05175600571 Prehistoric Unevaluated

SV-P5 05175600574 Historic Ineligible

TKN-J11 05175700096* Historic Unevaluated

TKN-J11 05175700097/05175700101* Prehistoric Ineligible

TKN-J11 05175700354* Prehistoric Ineligible

TKN-J13 05175700286 Multicomponent Unevaluated

TKN-J13 05175700287 Prehistoric Unevaluated

TKN-J6 05175700374 Prehistoric Unevaluated

TKN-J9 05175700508 Historic Ineligible

TKN-M2 05175700395* Multicomponent Unevaluated

TKN-M2 05175700397 Prehistoric Unevaluated

TKN-M2 05175700734 Prehistoric Unevaluated

TKN-Q1 05175700087 Prehistoric Unevaluated

TKN-Q1 05175700554 Prehistoric Ineligible

TKN-PP 05175700774 Prehistoric Unevaluated

TKS-11 05175700735 Prehistoric Unevaluated

TKS-11 05175700736 Prehistoric Unevaluated

TKS-M9 05175700450 Historic Ineligible

YRN-004 05175300676 Historic Unevaluated

YRN-007 05175300426 Prehistoric Unevaluated

YRN-008 05175300369 Historic Unevaluated

YRN-1 05175300881 Historic Unevaluated
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

536 – Tahoe National Forest

Route ID Site Number Site Type NRHP Status

YRN-2 05175300499 Historic Unevaluated

YRN-2 05175300545 Historic Unevaluated

YRN-2 05175300546 Historic Unevaluated

YRN-4 05175300386* Historic Unevaluated

YRN-509 05175300198 Historic Unevaluated

YRN-509 05175300205 Historic Unevaluated

YRN-7 05175300674 Historic Unevaluated

YRN-M2 05175300671 Historic Unevaluated

YRN-M2 05175300675 Historic Unevaluated

YRN-M2 05175300890 Historic Unevaluated

YRS-F1 05175300888 Historic Ineligible

YRS-SF5 05175500272 Historic Unevaluated

Unauthorized routes not included in 

any alternative

749 additional sites

Note: Under site type, prehistoric indicates Native American sites; historic designates sites that date from 1846 until 50 years ago,

and multicomponent refers to a location that contains artifacts and/or features from both time periods; * indicates a site listed 

multiple times but only counted once.

Table 3.05-4. Cultural Resource Sites Associated with Multiple Routes within the APE by Alternative

Route ID Site Number Alt 1 Alt 2 Alt 4 Alt 5 Alt 6 Alt 7

D_11E03_b 05175300016 X X X X

D_11E03_c 05175300016 X X X X

D_11E03_d 05175300016 X X X X

D_12E66_c 05175300156 X X X X X

D_12E66_d 05175300156 X X X X X

D_S-301_a 05175300176 X X X X X

H301-6 05175300176 X X

D_S-301_a 05175300188 X X X X X

H301-6 05175300188 X X

D_11E10_a 05175300386 X X X X

YRN-4 05175300386 X X X X X

D_12E66_a 05175300404 X X X X

D_12E67_d 05175300404 X X X X

D_S295_a 05175300436 X X X X X

D_S295_b 05175300436 X X X X X

D_12E66_a 05175300561 X X X X

D_12E67_d 05175300561 X X X X

D_S300_a 05175300595 X X X X X

D_S300_b 05175300595 X X X X X

D_14_b 05175500105 X X X X X

D_14_c 05175500105 X X

D_14_h 05175500105 X X

D_14_j 05175500105 X X X X X
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

Tahoe National Forest – 537

Route ID Site Number Alt 1 Alt 2 Alt 4 Alt 5 Alt 6 Alt 7

D_14-4 05175500105 X X

D_738-4_f 05175500363 X X X

D_738-4_g 05175500363 X X X

D_860-5_i 05175700096 X X

TKN-J11 05175700096 X X X X

D_03-4_a 05175700148 X X X X X

H3-4-4 05175700148 X X

Boca Reservoir “Open Area” 05175700240/CA-NEV-81 X X

H894-5-1 05175700240/CA-NEV-81 X X

D_270-8_b 05175700358 X X

D_270-8_c 05175700358 X X

D_886-10_a 05175700379 X X X X

D_886-18_a 05175700379 X X X X

D_886-18_b 05175700379 X X X X

H889-8 05175700395 X X

TKN-M2 05175700395 X X X X

N860-20-1 05175700540 X X

Stampede Reservoir “Open Area” 05175700540 X X

H889-3-18-5 05175700563 X X

N261-8-15-2 05175700563 X X

D_787-19 05175700756 X X

Prosser Reservoir “Open Area” 05175700756 X X

Note: Sites that have been determined ineligible were not included in this table. Alternative 3 was not listed on this table because no 

additions or changes to the NFTS would occur. 

Table 3.05-5. Summary of Cultural Resource Sites within the APE

Unevaluated Eligible Ineligible Total Number of Sites in APE Total Number of Unevaluated

and Eligible Sites in the APE

129 4 16 149 133

Table 3.05-6. Examples of Site Effects Documented at Cultural Resource Sites at Risk

Direct/Minor Effects Direct/Moderate Effects

§ Driving off-established routes onto cultural sites.

§ Motorized vehicle camping-related activities (e.g., 

digging fire pits) within boundaries of cultural sites.

§ Illicit digging activities (looting).

§ Routes traverse cultural resource sites causing 

displacement of artifacts.

§ Routes with improper drainage causing erosion.

§ In open areas, multiple vehicular tracks crisscrossing sites.

The magnitude of any effect to a cultural resource site’s integrity determines the severity of any 

direct, indirect, or cumulative effects. The following effect analysis identifies the scale and severity of 

potential adverse effects. Accordingly, effects are categorized based on a professional assessment of the 

data available to date: none/negligible, minor, moderate, and major. These categories represent a 

progressive scale that provides a qualitative assessment of the severity of any direct, indirect, or 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

538 – Tahoe National Forest

cumulative effects to the integrity of a cultural resource site. Routes in varying degrees have transected 

most sites in the APE. In some cases, effects to cultural resources were negligible (i.e., none) and no 

mitigation measures are required. However, monitoring was recommended in these situations or when 

effects were difficult to determine (i.e., camping at a very large quarry site).

Working definitions for the four severity categories are provided in Table 3.05-7. A severity rating of 

“minor” indicates that some relatively minor disturbance has been noted within the boundaries of the 

cultural resource site. A “minor” value indicates that, if present patterns of use are indicative of future 

trends, direct and indirect effects can most likely be avoided or lessened by employing the simplest of 

protection measures. In most cases, this would consist of installing barriers to keep vehicles on the route 

or within motorized vehicle based dispersed camping to a confined location.

If a cultural resource site is “moderately” susceptible to direct, indirect or cumulative effects, 

evidence of more extensive site disturbance has been noted. In this case, mitigation measures to avoid or 

minimize identified effects are required. Prescribed mitigation measures for moderate severity effects will 

most often take the form of physical barriers that prohibit off-route travel that could adversely affect 

cultural resources. Materials used may consist of timber, boulders, vegetation or other materials, or a 

combination thereof. A number of alternative mitigation measures could be employed, many of which are 

expressly described in the Motorized Recreation PA. In the event that the mitigation measures listed in the 

Motorized Recreation PA are inadequate or untenable, the PA will no longer apply and compliance with 

36 CFR §800 regulations will be necessary.

An effect severity rating of “major” indicates that the integrity of cultural resource site values would 

be affected in a significant way unless appropriate mitigation measures are implemented. A “major” value 

is reserved for those cases where a cultural resource site exhibits evidence of an adverse effect associated 

with past activities either directly or indirectly associated with the motorized use of an unauthorized route 

and these adverse effects will continue or increase if the route or area is added to the NFTS. Any major 

severity effects from proposed routes identified during this analysis were addressed through the Section 

106 process (i.e., evaluation of Site 05175300888) or the route was eliminated from consideration. No 

major severity effects to cultural resources exist under any of the action alternatives.

Table 3.05-7. Severity of Effects Definitions

Severity of 

Effects

Working Definition Explanatory Notes

None/Negligible Cultural resources are 

adjacent to routes but are 

not transected by a route or 

the route transects a portion 

of the site. The effect on 

NRHP values is insignificant.

If the effect on integrity measures is determined to be “negligible,” 

there is essentially no measurable effect on the cultural resource; 

therefore no mitigation measures are prescribed. Monitoring is 

recommended.

Minor Effects on cultural resources 

are relatively minor, but not 

insignificant. Integrity of the 

NRHP values may diminish 

if measures are not taken to 

alleviate the potential effect.

If the severity of effect is determined to be “minor,” some type of 

mitigation measure may be required. Most minor problems 

consist of indirect effects.

In some cases, monitoring is prescribed to ensure that the minor 

degree of disturbance (or potential for disturbance) initially noted 

does not increase in severity over time.

It is assumed for minor effects that an adaptive management 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

Tahoe National Forest – 539

Severity of 

Effects

Working Definition Explanatory Notes

strategy will be employed - a prescription specifically outlined in 

the Motorized Recreation PA. Signs, for example, may be erected 

as a first measure. If signs do not curtail potential adverse 

actions, more aggressive measures will be taken. Barriers (such 

as low impact barriers) are sometimes prescribed for minor 

threats when it appears as though the action responsible for the 

disturbance is well entrenched and not likely to be curtailed by the 

simple installation of a sign. The threshold between a “minor” and 

“moderate” threat is therefore more subjective than others.

Moderate Effects on cultural resources 

are either localized or noted 

in multiple areas. Materials 

associated with NRHP 

values exhibit some degree 

of damage or alteration, but 

NRHP integrity can be 

retained or improved if the 

detrimental activity is 

curtailed

If the integrity measure is determined to be “moderate,” some 

types of mitigation measures are required. In most cases the 

preferred method will be to erect a barrier large enough to prohibit 

vehicle traffic off the designated route, thereby eliminating the 

potential for an adverse effect to cultural resources. Padding of 

the cultural material in order to eliminate potential effect is also an 

option.

Major Effects on cultural resources 

are severe. If that particular 

route is added to the system 

without mitigation measures, 

the action would result in 

adverse effects to the NRHP 

values.

If the effect is determined to be “major,” more complex and 

potentially costly mitigation measures are required to prevent 

direct adverse effects to the resource. In some cases, potential 

mitigation measures can not be determined without additional 

consultation under 36 CFR §800.

Table 3.05-8 provides a summary of the effects to cultural resources at risk based on an analysis of 

effects to site integrity (i.e., degree to which the integrity of historic property values are diminished). The 

data categorize current forest-wide severity of effects if no action is taken to avoid adverse effects.

Table 3.05-8. At-Risk Sites Summarized According to Type and Severity of Effect based on Alternative 1

Unknown None Direct/Minor Direct/Moderate Major Total

8 11 80 34 None 133

Cultural Resources: Environmental Consequences

Considerations for all alternatives

This section discloses the environmental effects of each of the alternatives on cultural resources on the 

Forest. This analysis is focused on the effects of five management actions: (1) the prohibition of cross 

country motorized travel, (2) additions of currently unauthorized routes to the National Forest 

Transportation System (NFTS), (3) establishment of motorized “Open Areas,” (4) changes to the existing 

NFTS, and (5) Amendments to the Forest Plan. These 5 management actions have indicators that are used 

in determining effects for the proposed actions. The indicators were previously listed in the Cultural 

Resources Indicators section under the Effects Analysis Methodology. 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

540 – Tahoe National Forest

Direct and indirect effects common to all alternatives

To minimize redundancy, cross country travel, additions to the NFTS, establishment of “Open Areas,” 

changes to the NFTS, and amendments to the Forest Plan are addressed corporately in the following 

section for all seven of the alternatives. 

Cross Country Travel: For all of the action alternatives, the prohibition of motor vehicle use off 

designated transportation systems and areas would have a beneficial effect on cultural resources 

throughout the Forest in the short and long terms. It would curtail on-going potential for adverse effects 

and reduce the threat to cultural and historic properties that would occur if use were to continue on all 

unauthorized roads and trails. It would also help eliminate potential effects resulting from the creation of 

any new routes and trails if cross-country motorized vehicle use was not prohibited. Under this 

prohibition, most, if not all, future permitted or other authorized motorized vehicle travel off designated 

NFTS roads would be subject to NHPA Section 106 compliance and potential effects to cultural and 

historic properties can be identified at that time. Under Alternative 1, cross country travel would continue, 

except for areas previously prohibited to motorized use.

Additions to the NFTS: This is addressed individually under each alternative discussion, except for 

Alternatives 1 and 3, which do not add any routes to the NFTS.

Establishment of Motorized “Open Areas”: This is addressed individually under Alternatives 2 and 

6, the only alternatives to establish “Open Areas.” The establishment of “Open Areas” would not affect 

cultural resources in Alternatives 1, 3, 4, 5, and 7 as no “Open Areas” are proposed.

Changes to the existing NFTS: Proposed changes to the existing NFTS are minimal. A modification 

proposed to existing system routes is a change in permitted vehicle class. For purposes of this cultural 

resource assessment, it is assumed that there is no measurable difference in the magnitude of effects to 

cultural resources between full-size four-wheel drive vehicles, passenger vehicles, specialized offhighway vehicles, and single-track motorcycle trails. Based on the current data available, there is no 

measurable difference in the scale of potential damage to cultural resources, regardless of vehicle size or 

type.

Change in season of use has no effect on cultural resources and will not be addressed under each 

alternative. 

The changes to the NFTS resulting from reopening Maintenance Level 1 (ML 1) roads will be 

addressed under Alternatives 4, 5, 6, and 7 since those are the only alternatives that add ML 1 roads to the 

NFTS.

Amendments to the Forest Plan: There is no effect to cultural resources from amending the Forest 

Plan; therefore, this will not be addressed under each alternative.

Effects of Mitigation Measures on Cultural Resources: As described in Chapter 2 (The 

Alternatives) and Appendix A (Site Specific Road, Trail and Open Area Information), mitigation measures 

have been proposed to eliminate or lessen direct, indirect, and cumulative effects on forest resources. 

Some mitigation may consist of ground-disturbing activities with the potential to adversely affect cultural 

resources. In this section, all proposed mitigation measures are reviewed and those with the potential to 

affect cultural resources are identified and analyzed.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

Tahoe National Forest – 541

Certain mitigation measures have little or no potential to affect cultural resources because they do not 

involve ground or surface disturbance. Mitigations that do not pose a threat include: monitoring, seasonal 

closures, installation of single-post signs, and installation of non-intrusive barriers to control traffic flow. 

Weed removal mitigations also pose no threat to cultural resources. The mitigation measures listed in this 

paragraph have little or no potential to affect cultural resources and are therefore exempt from further 

analysis.

Site specific effects: Table 3.05-9 shows the site specific motorized effects on at risk cultural 

resource sites by alternative. Sites that have been determined ineligible have been removed from this table 

and the specific alternative tables. The protection measures initially prescribed may qualify as the 

minimal actions necessary to alleviate potential adverse effects. The Motorized Recreation PA mandates 

that all at-risk properties within the APE be monitored over a two-year period after designation. If 

monitoring demonstrates that protection measures initially prescribed prove ineffective, other protection 

measures in the PA will be used as appropriate or the SHPO will be consulted to identify other resource 

protection or management needs. This type of adaptive management approach is an option in the 

Motorized Recreation PA. Table 3.05-10 summarizes motorized effects on at-risk cultural resources by 

alternative.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

542 – Tahoe National Forest

Table 3.05-9. Site Specific Motorized Effects on Cultural Resources at Risk by Alternative

Route ID Site Number Effect Type/Severity Protection Measure Alt 1 Alt 2 Alt 4 Alt 5 Alt 6 Alt 7

25-9_p 05175300469 Displacement Direct/minor Monitor X X X

491-3_1 05175300337 None None Monitor X X X

491-3_2 05175300216 Displacement Direct/minor Monitor X

Boca Reservoir 

“Open Area”

05175700303 Displacement Direct/minor Install barriers to keep 

users on system route

X X

Boca Reservoir 

“Open Area”

05175700305 Displacement Direct/minor Install barriers to keep 

users on system route

X X

Boca Reservoir 

“Open Area”

05175700307 Displacement Direct/minor Install barriers to keep 

users on system route

X X

Boca Reservoir 

“Open Area”

05175700240/CA-NEV-81* Displacement Direct/minor Install barriers to keep 

users on system routes

X X

Boca Reservoir 

“Open Area”

CA-NEV-26 Displacement Direct/moderate Site is below high water in 

closed BOR area.

Demarcate closed area.

X X

Boca Reservoir 

“Open Area”

05175700747 Displacement Direct/moderate Install barriers X X

Boca Reservoir 

“Open Area”

05175700749 Displacement Direct/moderate Install barriers X X

Boca Reservoir 

“Open Area”

05175700750 Displacement Direct/moderate Install barriers X X

Boca Reservoir 

“Open Area”

05175700775 Displacement Direct/moderate Install barriers X X

Boca Reservoir 

“Open Area”

05175700776 Displacement Direct/moderate Install barriers X X

Boca Reservoir 

“Open Area”

05175700777 Displacement Direct/moderate Install barriers X X

H11E10 05175300696 Displacement Direct/minor Monitor X X

H301-6 05175300176* Displacement Direct/minor Monitor X X

H301-6 05175300188* Displacement Direct/minor Monitor X X

H3-4-4 05175700148* Displacement Direct/minor Monitor X X

H54-9 05175600283 Displacement Direct/minor Monitor X X

H54-9 05175600341 Displacement Direct/minor Monitor X X

H54-9 05175600317 Displacement Direct/minor Monitor X X
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

Tahoe National Forest – 543

Route ID Site Number Effect Type/Severity Protection Measure Alt 1 Alt 2 Alt 4 Alt 5 Alt 6 Alt 7

H88-44 05175400215 Displacement Direct/minor Monitor X X

H889-28 05175700088 Displacement Direct/minor Monitor X X

H889-3-18-5 05175700563* Displacement Direct/minor Monitor X X

H889-8 05175700395* Displacement Direct/minor Monitor X X

H889-8 05175700401 Displacement Direct/minor Monitor X X

H894-5-1 05175700240/CA-NEV-81* Displacement Direct/minor Monitor X X

N25-1-1 05175300347 Displacement Direct/minor Monitor X X

N25-1-1 05175300348 Displacement Direct/minor Monitor X X

N25-2 05175300454 Displacement Direct/minor Monitor X X

N25-6-1 05175300356 Displacement Direct/minor Monitor X X

N25-7 05175300034 Displacement Direct/minor Monitor X X

N261-8-15-2 05175700563* Displacement Direct/minor Monitor X X

N27-3 05175300514 Displacement Direct/minor Monitor X X

N27-5 05175300446 Displacement Direct/minor Monitor X X

N39-5 05175300217 Displacement/looting Direct/minor Monitor X X

N43-6-2 05175400368 Displacement Direct/minor Monitor X X

N860-20-1 05175600426 Displacement Direct/minor Monitor X X

N860-20-1 05175700540* Displacement Direct/minor Monitor X X

N886-14-10 05175700577 Displacement Direct/minor Monitor X X

N886-1-5 05175700009 Displacement Direct/minor Monitor X X

N886-1-5 05175700409 Displacement Direct/minor Monitor X X

N886-18-10 05175700447 Displacement Direct/minor Monitor X X

N886-18-10 05175700529 Displacement Direct/minor Monitor X X

N889-3-30-10 05175700304 Displacement Direct/minor Monitor X X

N890-14-5 05175700511 Displacement Direct/minor Monitor X X

N96-34-2-6 05175400325 Displacement Direct/minor Monitor X X

Prosser Reservoir 

“Open Area”

05175700609 Displacement/shoreline 

erosion/high level of 

motorized use

Direct/moderate Install barriers X X
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

544 – Tahoe National Forest

Route ID Site Number Effect Type/Severity Protection Measure Alt 1 Alt 2 Alt 4 Alt 5 Alt 6 Alt 7

Prosser Reservoir 

“Open Area”

05175700608/CA-NEV-64 Displacement/shoreline 

erosion/ high level of 

motorized use

Direct/moderate Install barriers X X

Prosser Reservoir 

“Open Area”

05175700753 Displacement/ high

level of motorized use

Direct/moderate Install barriers X X

Prosser Reservoir 

“Open Area”

05175700754 Displacement/ high 

level of motorized use

Direct/moderate Install barriers X X

Prosser Reservoir 

“Open Area”

05175700755 Displacement/ high 

level of motorized use

Direct/moderate Install barriers X X

Prosser Reservoir 

“Open Area”

05175700756* Displacement Direct/minor Install barriers X X

Prosser Reservoir 

“Open Area”

05175700757 Displacement/ high 

level of motorized use

Direct/moderate Install barriers X X

Prosser Reservoir 

“Open Area”

05175700758 Displacement/ high 

level of motorized use

Direct/moderate Install barriers X X

Prosser Reservoir 

“Open Area”

05175700759 Displacement/ high 

level of motorized use

Direct/moderate Install barriers X X

Prosser Reservoir 

“Open Area”

05175700760 Displacement/ high 

level of motorized use

Direct/moderate Install barriers X X

Prosser Reservoir 

“Open Area”

05175700761 Displacement/ high 

level of motorized use

Direct/moderate Install barriers X X

Prosser Reservoir 

“Open Area”

05175700762 Displacement/high 

level of motorized use

Direct/moderate Install barriers X X

Stampede Reservoir 

“Open Area”

05175700535 Displacement Direct/moderate Install barriers to keep 

users on route

X X

Stampede Reservoir 

“Open Area”

05175700540* Displacement Direct/moderate Install barriers to keep 

users on route

X X

Stampede Reservoir 

“Open Area”

05175700004/SIE-S44 Displacement/shoreline 

erosion

Direct/minor Install barriers X X

Stampede Reservoir 

“Open Area”

05175700763 Displacement Direct/moderate Install barriers X X

Stampede Reservoir 

“Open Area”

05175700764 Displacement Direct/moderate Install barriers X X

Stampede Reservoir 

“Open Area”

05175700765 Displacement Direct/moderate Install barriers X X
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

Tahoe National Forest – 545

Route ID Site Number Effect Type/Severity Protection Measure Alt 1 Alt 2 Alt 4 Alt 5 Alt 6 Alt 7

Stampede Reservoir 

“Open Area”

05175700766 Displacement Direct/moderate Install barriers X X

Stampede Reservoir 

“Open Area”

05175700767 Displacement Direct/moderate Install barriers X X

Stampede Reservoir 

“Open Area”

05175700768 Displacement Direct/moderate Install barriers X X

Stampede Reservoir 

“Open Area”

05175700769 Displacement Direct/moderate Install barriers X X

Stampede Reservoir 

“Open Area”

05175700770 Displacement Direct/moderate Install barriers X X

Stampede Reservoir 

“Open Area”

DWR-S-1 Unknown-below 

waterline

Unknown N/A X X

Stampede Reservoir 

“Open Area”

SIE-11 Unknown-below 

waterline

Unknown N/A X X

Stampede Reservoir 

“Open Area”

SIE-12 Unknown-below 

waterline

Unknown N/A X X

Stampede Reservoir 

“Open Area”

SIE-13 Unknown-below 

waterline

Unknown N/A X X

Stampede Reservoir 

“Open Area”

SIE-14 Unknown-below 

waterline

Unknown N/A X X

Stampede Reservoir 

“Open Area”

SIE-15 Unknown-below 

waterline

Unknown N/A X X

Stampede Reservoir 

“Open Area”

SIE-16 Unknown-below 

waterline

Unknown N/A X X

Stampede Reservoir 

“Open Area”

SIE-17 Unknown-below 

waterline

Unknown N/A X X

D_25_d 05175300004 Displacement Direct/minor Monitor X X X X X

D_11E03_b 05175300016* Displacement/Camping Direct/minor Monitor X X X X

D_11E03_c 05175300016* Displacement/Camping Direct/minor Monitor X X X X

D_11E03_d 05175300016* Displacement/Camping Direct/minor Monitor X X X X

D_721-2_a 05175300074 Displacement/Camping Direct/minor Monitor X X X X X

D_12E66_c 05175300156* Camping Direct/minor Monitor X X X X X

D_12E66_d 05175300156* Camping Direct/minor Monitor X X X X X

D_S-301_a 05175300176* Camping Direct/minor Monitor X X X X X
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

546 – Tahoe National Forest

Route ID Site Number Effect Type/Severity Protection Measure Alt 1 Alt 2 Alt 4 Alt 5 Alt 6 Alt 7

D_S-301_a 05175300188* Camping Direct/minor Monitor X X X X X

D_11E10_a 05175300386* None None Monitor X X X X

D_12E66_a 05175300404* Camping Direct/minor Monitor X X X X

D_12E66_a 05175300561* Camping Direct/minor Monitor X X X X

D_12E67_d 05175300404* Camping Direct/minor Monitor X X X X

D_12E67_d 05175300561* Camping Direct/minor Monitor X X X X

D_S295_a 05175300436* Camping Direct/minor Monitor X X X X X

D_S295_b 05175300436* Camping Direct/minor Monitor X X X X X

D_12E68_a 05175300455 Camping Direct/minor Monitor X X X X X

D_S300_a 05175300595* Camping Direct/minor Monitor X X X X X

D_S300_b 05175300595* Camping Direct/minor Monitor X X X X X

D_738-4_a 05175300883 Camping Direct/minor Monitor X X X X

D_12E66_b 05175300892 Camping Direct/minor Monitor X X X X

D_6149-31 05175400008 Camping/looting Direct/minor Monitor X X

D_P88_d 05175400176 None None Monitor X X

D_P88_b 05175400312 Camping Direct/minor Monitor X X X X X

D_14_b 05175500105* Camping Direct/minor Monitor X X X X X

D_14_c 05175500105* Camping Direct/minor Monitor X X

D_14_h 05175500105* Camping Direct/minor Monitor X X

D_14_j 05175500105* Camping Direct/minor Monitor X X X X X

D_14-4 05175500105* Camping Direct/minor Monitor X X

D_18-19_a 05175500344 Camping Direct/minor Monitor X X X X X

D_738-4_f 05175500363* Camping Direct/minor Monitor X X X

D_738-4_g 05175500363* Camping Direct/minor Monitor X X X

D_738-4_e 05175500364 Camping Direct/minor Monitor X X X

D_5_b 05175600018 Camping Direct/minor Monitor X X

D_16TH19-1 05175600119 Camping Direct/minor Monitor X X

D_7-10 05175600164 Camping Direct/minor Monitor X X

D_860-42 05175600202 Camping Direct/minor Monitor X X

D_S450 05175600338 Camping Direct/minor Monitor X X
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

Tahoe National Forest – 547

Route ID Site Number Effect Type/Severity Protection Measure Alt 1 Alt 2 Alt 4 Alt 5 Alt 6 Alt 7

D_5_a 05175600394 Camping Direct/minor Monitor X X

D_860-25 05175600421 Camping Direct/minor Monitor X X

D_SV-M1 05175600431 Camping Direct/minor Monitor X X

D_560-20_b 05175600442 Camping Direct/minor Monitor X X

D_03-4_a 05175700148* Camping Direct/minor Monitor X X X X X

D_270-8_b 05175700358* Camping Direct/minor Monitor X X

D_270-8_c 05175700358* Camping Direct/minor Monitor X X

D_886-10_a 05175700379* Camping Direct/minor Monitor X X X X

D_886-18_a 05175700379* Camping Direct/minor Monitor X X X X

D_886-18_b 05175700379* Camping Direct/minor Monitor X X X X

D_S860_a 05175700620 Camping Direct/minor Monitor X X

D_787-19 05175700756* Camping Direct/minor Monitor X X

D_450-101_a 05175700779 Camping Direct/minor Monitor X X X X

D_860-5_i 05175700096* Camping None None X X

D_N886_18C 05175700778 Camping Direct/minor Monitor X X

SV-P14 05175600571 Displacement Direct/minor Install barriers to keep 

users on route

X X X X X X

TKN-J11 05175700096* Camping None None X X X X

TKN-J13 05175700286 Displacement/shoreline 

erosion

Direct/moderate Install barriers X X X X X X

TKN-J13 05175700287 Displacement/shoreline 

erosion

Direct/moderate Install barriers X X X X X X

TKN-J6 05175700374 Displacement/camping Direct/minor Recreation mitigation

(barriers) 

X X X X X

TKN-M2 05175700395* Displacement Direct/minor Install barriers to keep 

users on route

X X X X

TKN-M2 05175700397 Displacement Direct/minor Install barriers to keep 

users on route

X X X X

TKN-M2 05175700734 Erosion/Displacement Direct/moderate Install barriers to keep 

users on routeX X X X

TKN-Q1 05175700087 Displacement Direct/minor Monitor X X X X

TKN-PP 05175700774 Displacement Direct/minor Monitor X X
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

548 – Tahoe National Forest

Route ID Site Number Effect Type/Severity Protection Measure Alt 1 Alt 2 Alt 4 Alt 5 Alt 6 Alt 7

TKS-11 05175700735 None None None X X X X X

TKS-11 05175700736 None None Monitor X X X X X

YRN-004 05175300676 Displacement Direct/minor Monitor X X X

YRN-007 05175300426 None None Monitor X X X

YRN-008 05175300369 Displacement

/rutting

Direct/moderate Install barriers to keep 

users on route and to 

designate camping areas.

X X X X

YRN-1 05175300881 None None Monitor X X X X X

YRN-2 05175300499 Erosion Direct/moderate Monitor- X X X X X

YRN-2 05175300545 Displacement Direct/minor Install barriers to keep 

users on route

X X X X X

YRN-2 05175300546 None None Monitor X X X X X

YRN-4 05175300386* None None Monitor X X X X X

YRN-509 05175300198 Displacement Direct/minor Install barriers to prohibit 

use on spur road off main 

route

X X X

YRN-509 05175300205 Displacement Direct/minor Install barriers to prohibit 

use on spur road off main 

route

X X X

YRN-7 05175300674 Erosion Direct/moderate Monitor-. X X X X

YRN-M2 05175300671 Erosion Direct/moderate Monitor- X X X

YRN-M2 05175300675 Displacement Direct/minor Monitor X X X

YRN-M2 05175300890 None None Monitor X X X

YRS-SF5 05175500272 None None Monitor X X X X X X

Unauthorized routes 

not included in any 

alternative

749 additional sites

Note: Sites that have been determined ineligible were not included in this table. Alternative 3 was not listed on this table because no additions or changes to the NFTS would occur;

* indicates a site listed multiple times but only counted once.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

Tahoe National Forest – 549

Table 3.05-10. Summary Comparison of Effect, Type, and Severity on At Risk Cultural Resources

Effect Type/Severity Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Displacement/erosion/rutting Direct/Moderate 34 34 0 2 7 5 4

Displacement/camping/looting Direct/Minor 80 34 0 13 60 45 3 

None or Unknown None 19 17 0 1 10 9 6

Total 133 85 0 16 77 59 13

Cross Country Travel Continues Prohibited Prohibited Prohibited Prohibited Prohibited Prohibited

Alternative 1: No Action

The No Action Alternative provides a baseline for comparing the other alternatives. Under the No Action 

Alternative, no changes would be made to the NFTS and there would be no prohibition of cross country 

travel. Current management plans would continue to guide project area management. The Travel 

Management Rule would not be implemented, and no motor vehicle use map (MVUM) would be 

published. Motor vehicle travel by the public would not be limited to designated routes. Unauthorized 

routes would continue to proliferate and would have no status or authorization as NFTS facilities.

Direct and Indirect Effects

General effects of the No Action Alternative on cultural resources have been addressed in the 

Environmental Consequences section (above). One hundred thirty-three (133) cultural resource sites have 

been identified as resources at risk within the APE. They are vulnerable to effects if no action is taken to 

manage motorized use. An additional 749 sites are located near, or are transected by, unauthorized routes 

not addressed under any alternative in this analysis; these sites are also resources at risk. To quantify 

potential cumulative effects, one can calculate the average number of previously identified cultural 

resource sites per acre that would be susceptible to new routes created in the future without a prohibition. 

Within the TNF, 3,228 cultural resources sites have been identified. Site density averages .004 cultural 

resource sites for every acre. Excluding the 133 cultural resource sites that have already been identified 

(Table 3.05-5) within the APE, upwards of 3,095 additional cultural resource sites could be susceptible to 

an adverse effect if no management actions were implemented (this number includes the 749 sites 

associated with unauthorized routes not addressed under any alternative in this analysis).

Under Alternative 1, cross country travel would not be prohibited. There would be no management of 

any known unauthorized motorized routes. An unknown number of additional routes not being proposed 

in this project would continue to be used. Of the 133 cultural resource sites located within this alternative

(refer to Table 3.05-4), 34 sites have moderate effects and 80 have minor effects that would continue and 

likely increase. The type and severity of effects for the remaining 19 is “none” or unknown (unknown was 

used for sites that were under water). Since cross country travel could occur anywhere on the forest, an 

unidentified number of cultural resources could be affected including the 749 sites located near or 

transected by unauthorized routes not addressed under any alternative in this analysis. This alternative 

does not propose any mitigation for these potential effects. Alternative 1 would have unmitigated adverse 

effects on upwards of 882 cultural resource sites (133 sites within the APE and 749 sites associated with 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

550 – Tahoe National Forest

unauthorized routes not addressed under any alternative in this analysis); it would not meet the 

requirements of Section 106 of the NHPA.

Table 3.05-11. Summary of Effects to Cultural Resources at Risk: Alternative 1

Route ID Site Number Effect Type/Severity Alt 1

25-9_p 05175300469 Displacement Direct/minor X

491-3_1 05175300337 None None X

491-3_2 05175300216 Displacement Direct/minor X

Boca Reservoir “Open Area” 05175700303 Displacement Direct/minor X

Boca Reservoir “Open Area” 05175700305 Displacement Direct/minor X

Boca Reservoir “Open Area” 05175700307 Displacement Direct/minor X

Boca Reservoir “Open Area” 05175700240/CA-NEV-81* Displacement Direct/minor X

Boca Reservoir “Open Area” CA-NEV-26 Displacement Direct/moderate X

Boca Reservoir “Open Area” 05175700747 Displacement Direct/moderate X

Boca Reservoir “Open Area” 05175700749 Displacement Direct/moderate X

Boca Reservoir “Open Area” 05175700750 Displacement Direct/moderate X

Boca Reservoir “Open Area” 05175700775 Displacement Direct/moderate X

Boca Reservoir “Open Area” 05175700776 Displacement Direct/moderate X

Boca Reservoir “Open Area” 05175700777 Displacement Direct/moderate X

H11E10 05175300696 Displacement Direct/minor X

H301-6 05175300176* Displacement Direct/minor X

H301-6 05175300188* Displacement Direct/minor X

H3-4-4 05175700148* Displacement Direct/minor X

H54-9 05175600283 Displacement Direct/minor X

H54-9 05175600341 Displacement Direct/minor X

H54-9 05175600317 Displacement Direct/minor X

H88-44 05175400215 Displacement Direct/minor X

H889-28 05175700088 Displacement Direct/minor X

H889-3-18-5 05175700563* Displacement Direct/minor X

H889-8 05175700395* Displacement Direct/minor X

H889-8 05175700401 Displacement Direct/minor X

H894-5-1 05175700240/CA-NEV-81* Displacement Direct/minor X

N25-1-1 05175300347 Displacement Direct/minor X

N25-1-1 05175300348 Displacement Direct/minor X

N25-2 05175300454 Displacement Direct/minor X

N25-6-1 05175300356 Displacement Direct/minor X

N25-7 05175300034 Displacement Direct/minor X

N261-8-15-2 05175700563* Displacement Direct/minor X

N27-3 05175300514 Displacement Direct/minor X

N27-5 05175300446 Displacement Direct/minor X

N39-5 05175300217 Displacement/

looting

Direct/minor X

N43-6-2 05175400368 Displacement Direct/minor X
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

Tahoe National Forest – 551

Route ID Site Number Effect Type/Severity Alt 1

N860-20-1 05175600426 Displacement Direct/minor X

N860-20-1 05175700540* Displacement Direct/minor X

N886-14-10 05175700577 Displacement Direct/minor X

N886-1-5 05175700009 Displacement Direct/minor X

N886-1-5 05175700409 Displacement Direct/minor X

N886-18-10 05175700447 Displacement Direct/minor X

N886-18-10 05175700529 Displacement Direct/minor X

N889-3-30-10 05175700304 Displacement Direct/minor X

N890-14-5 05175700511 Displacement Direct/minor X

N96-34-2-6 05175400325 Displacement Direct/minor X

Prosser Reservoir “Open Area” 05175700609 Displacement/shoreline 

erosion

Direct/moderate X

Prosser Reservoir “Open Area” 05175700608/CA-NEV-64 Displacement/shoreline 

erosion

Direct/moderate X

Prosser Reservoir “Open Area” 05175700753 Displacement Direct/moderate X

Prosser Reservoir “Open Area” 05175700754 Displacement Direct/moderate X

Prosser Reservoir “Open Area” 05175700755 Displacement Direct/moderate X

Prosser Reservoir “Open Area” 05175700756* Displacement Direct/minor X

Prosser Reservoir “Open Area” 05175700757 Displacement Direct/moderate X

Prosser Reservoir “Open Area” 05175700758 Displacement Direct/moderate X

Prosser Reservoir “Open Area” 05175700759 Displacement Direct/moderate X

Prosser Reservoir “Open Area” 05175700760 Displacement Direct/moderate X

Prosser Reservoir “Open Area” 05175700761 Displacement Direct/moderate X

Prosser Reservoir “Open Area” 05175700762 Displacement Direct/moderate X

Stampede Reservoir “Open Area” 05175700535 Displacement Direct/moderate X

Stampede Reservoir “Open Area” 05175700540* Displacement Direct/moderate X

Stampede Reservoir “Open Area” 05175700004/SIE-S44 Displacement/shoreline 

erosion/looting

Direct/minor X

Stampede Reservoir “Open Area” 05175700763 Displacement Direct/moderate X

Stampede Reservoir “Open Area” 05175700764 Displacement Direct/moderate X

Stampede Reservoir “Open Area” 05175700765 Displacement Direct/moderate X

Stampede Reservoir “Open Area” 05175700766 Displacement Direct/moderate X

Stampede Reservoir “Open Area” 05175700767 Displacement Direct/moderate X

Stampede Reservoir “Open Area” 05175700768 Displacement Direct/moderate X

Stampede Reservoir “Open Area” 05175700769 Displacement Direct/moderate X

Stampede Reservoir “Open Area” 05175700770 Displacement Direct/moderate X

Stampede Reservoir “Open Area” DWR-S-1 Unknown-below 

waterline

Unknown X

Stampede Reservoir “Open Area” SIE-11 Unknown-below 

waterline

Unknown X

Stampede Reservoir “Open Area” SIE-12 Unknown-below 

waterline

Unknown X

Stampede Reservoir “Open Area” SIE-13 Unknown-below 

waterline

Unknown X
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Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

552 – Tahoe National Forest

Route ID Site Number Effect Type/Severity Alt 1

Stampede Reservoir “Open Area” SIE-14 Unknown-below 

waterline

Unknown X

Stampede Reservoir “Open Area” SIE-15 Unknown-below 

waterline

Unknown X

Stampede Reservoir “Open Area” SIE-16 Unknown-below 

waterline

Unknown X

Stampede Reservoir “Open Area” SIE-17 Unknown-below 

waterline

Unknown X

D_25_d 05175300004 Displacement Direct/minor X

D_11E03_b 05175300016* Displacement/Camping Direct/minor X

D_11E03_c 05175300016* Displacement/Camping Direct/minor X

D_11E03_d 05175300016* Displacement/Camping Direct/minor X

D_721-2_a 05175300074 Displacement/Camping Direct/minor X

D_12E66_c 05175300156* Camping Direct/minor X

D_12E66_d 05175300156* Camping Direct/minor X

D_S-301_a 05175300176* Camping Direct/minor X

D_S-301_a 05175300188* Camping Direct/minor X

D_11E10_a 05175300386* None None X

D_12E66_a 05175300404* Camping Direct/minor X

D_12E66_a 05175300561* Camping Direct/minor X

D_12E67_d 05175300404* Camping Direct/minor X

D_12E67_d 05175300561* Camping Direct/minor X

D_S295_a 05175300436* Camping Direct/minor X

D_S295_b 05175300436* Camping Direct/minor X

D_12E68_a 05175300455 Camping Direct/minor X

D_S300_a 05175300595* Camping Direct/minor X

D_S300_b 05175300595* Camping Direct/minor X

D_738-4_a 05175300883 Camping Direct/minor X

D_12E66_b 05175300892 Camping Direct/minor X

D_6149-31 05175400008 Camping/looting Direct/minor X

D_P88_d 05175400176 None None X

D_P88_b 05175400312 Camping Direct/minor X

D_14_b 05175500105* Camping Direct/minor X

D_14_c 05175500105* Camping Direct/minor X

D_14_h 05175500105* Camping Direct/minor X

D_14_j 05175500105* Camping Direct/minor X

D_14-4 05175500105* Camping Direct/minor X

D_18-19_a 05175500344 Camping Direct/minor X

D_738-4_f 05175500363* Camping Direct/minor X

D_738-4_g 05175500363* Camping Direct/minor X

D_738-4_e 05175500364 Camping Direct/minor X

D_5_b 05175600018 Camping Direct/minor X

D_16TH19-1 05175600119 Camping Direct/minor X
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

Tahoe National Forest – 553

Route ID Site Number Effect Type/Severity Alt 1

D_7-10 05175600164 Camping Direct/minor X

D_860-42 05175600202 Camping Direct/minor X

D_S450 05175600338 Camping Direct/minor X

D_5_a 05175600394 Camping Direct/minor X

D_860-25 05175600421 Camping Direct/minor X

D_SV-M1 05175600431 Camping Direct/minor X

D_560-20_b 05175600442 Camping Direct/minor X

D_03-4_a 05175700148* Camping Direct/minor X

D_270-8_b 05175700358* Camping Direct/minor X

D_270-8_c 05175700358* Camping Direct/minor X

D_886-10_a 05175700379* Camping Direct/minor X

D_886-18_a 05175700379* Camping Direct/minor X

D_886-18_b 05175700379* Camping Direct/minor X

D_S860_a 05175700620 Camping Direct/minor X

D_787-19 05175700756* Camping Direct/minor X

D_450-101_a 05175700779 Camping Direct/minor X

D_860-5_i 05175700096 Camping None X

D_N886_18C 05175700778 Camping Direct/minor X

SV-P14 05175600571 Displacement Direct/minor X

TKN-J11 05175700096 Camping None X

TKN-J13 05175700286 Displacement/shoreline 

erosion

Direct/moderate X

TKN-J13 05175700287 Displacement/shoreline 

erosion

Direct/moderate X

TKN-J6 05175700374 Displacement/camping Direct/minor X

TKN-M2 05175700395* Displacement Direct/minor X

TKN-M2 05175700397 Displacement Direct/minor X

TKN-M2 05175700734 Erosion/

Displacement

Direct/moderate X

TKN-Q1 05175700087 Displacement Direct/minor X

TKN-PP 05175700774 Displacement Direct/minor X

TKS-11 05175700735 None None X

TKS-11 05175700736 None None X

YRN-004 05175300676 Erosion Direct/moderate X

YRN-007 05175300426 None None X

YRN-008 05175300369 Displacement/rutting Direct/moderate X

YRN-1 05175300881 None None X

YRN-2 05175300499 Erosion Direct/moderate X

YRN-2 05175300545 Displacement Direct/minor X

YRN-2 05175300546 None None X

YRN-4 05175300386* None None X

YRN-509 05175300198 Displacement Direct/minor X

YRN-509 05175300205 Displacement Direct/minor X
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

554 – Tahoe National Forest

Route ID Site Number Effect Type/Severity Alt 1

YRN-7 05175300674 Erosion Direct/moderate X

YRN-M2 05175300671 Erosion Direct/moderate X

YRN-M2 05175300675 Displacement Direct/minor X

YRN-M2 05175300890 None None X

YRS-SF5 05175500272 None None X

Note: * indicates a site listed multiple times, but only counted once.

Alternative 2: Increased Motorized Recreation and Access Opportunities

Alternative 2 responds to public scoping of insufficient public motorized opportunities and motorized 

access for dispersed recreation in the proposed action. This alternative is based on the Proposed Action 

(Alternative 7), with additional routes and mixed use to provide more access and motorized recreation 

opportunities.

Direct and Indirect Effects

Under Alternative 2, cross country travel would be prohibited and a total of 59.6 miles of unauthorized 

motorized routes (5 miles of road and 54.6 miles of trails) would be added to the NFTS. Additionally,

four motorized “Open Areas” would be established for a total of 2,649 acres (Greenhorn, Boca Reservoir, 

Prosser Reservoir, and Stampede Reservoir). There are a total 85 sites within the APE for this alternative

(8 sites are associated with multiple routes; they are noted in Table 3.05-12 with an *).

Additions to the NFTS: Twenty-seven (27) sites outside of the proposed “Open Areas” at three 

reservoirs in this alternative were noted as having direct/minor effects. Seven (7) sites outside of the 

reservoirs have a rating of direct/moderate. The type and severity of effects for the remaining 9 sites is 

“none”. Sites determined ineligible for the NRHP were removed from the table (Table 3.05-12). 

Protection measures include installing barriers to keep users on system routes. At 6 sites, mitigations (i.e., 

barriers) from recreation, watershed, and botany would facilitate protecting the sites. Monitoring is 

recommended to determine if additional protection measures would be needed in the future (such as at 

Site 05175300004 where interpretive signage or developing an interpretive trail may be appropriate). At 

many of the sites where camping occurs for example, it was difficult to identify effects caused by 

motorized vehicles. Monitoring at these locations will be used to assess site condition over time.

Establish Motorized “Open Areas”: Alternative 2 establishes motorized use “Open Areas” below 

the high water line at Boca, Prosser, and Stampede Reservoirs. Limited surveys were conducted at Boca, 

Prosser, and Stampede at the high use areas and shoreline access points (off of existing NFTS routes).

Approximately 300 acres were surveyed. There are no cultural resources within the proposed Greenhorn 

“Open Area.”

Boca dam was constructed in 1937 and there was no archaeological survey completed prior to 

construction. Both Prosser and Stampede Reservoirs were surveyed ca. 1957 by the Bureau of 

Reclamation (BOR). At Prosser, constructed in 1962, two prehistoric sites were excavated, NEV-11 and 

NEV-67. At Stampede, constructed in 1970, two prehistoric sites were excavated, SIE-28 and SIE-S44.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

Tahoe National Forest – 555

SIE-S44 was subsequently listed on the National Register of Historic Places. As the survey and cultural 

resource site recording at Prosser and Stampede was done by 1957 standards, historic sites were not 

recorded. Site locations were placed on 15 minute quadrangle maps making cross correlations with 

current observations extremely difficult. For example, the precise location of NEV-11 and NEV-67 onthe-ground has not been ascertained with confidence. This is due to multiple factors including 1957 

mapping scales, vegetation changes (i.e., no vegetation now below the high water line increasing 

visibility) and other factors. Motorized use below the high water line has been allowed since the 

reservoirs were established. Subsequently, there is high motorized use at both Boca and Prosser, but the 

use is higher at Prosser due to its close proximity to the Town of Truckee and several subdivisions 

constructed adjacent to the reservoir.

Motorized access to shoreline below the high water line at these reservoirs has direct/minor effects to 

7 sites and direct/moderate effects to 27 cultural sites (one is a NRHP listed site). The type and severity of 

effects for the remaining 8 sites is unknown (they were under water at Stampede Reservoir). The more 

severe effects to these sites are not always associated with motorized vehicles. The non-motorized 

impacts are most often associated with shoreline erosion (wave action, deflation). There is also 

documented artifact collecting (looting) that has occurred at the NRHP listed site that was a legal action a 

few years ago from nearby private property residents. The shoreline erosion is having moderate effects on 

these sites. Other than Alternatives 2 and 6, the other action alternatives do not establish these reservoirs 

as motorized “Open Areas,” but the effects resulting from shoreline erosion will continue. A mitigation

measure includes installing barriers to keep users on system routes or to keep users off of the cultural 

resource sites; this may be difficult to implement at Boca, Prosser, and Stampede Reservoirs due to the 

flat open terrain. Monitoring will be used to assess the effectiveness of installing barriers.

Table 3.05-12. Summary of Effects to Cultural Resources at Risk: Alternative 2

Route ID Site Number Effect Type/Severity Protection Measure Alt 2

Boca Reservoir 

“Open Area”

05175700303 Displacement Direct/minor Install barriers to 

keep users on 

system route

X

Boca Reservoir 

“Open Area”

05175700305 Displacement Direct/minor Install barriers to 

keep users on 

system route

X

Boca Reservoir 

“Open Area”

05175700307 Displacement Direct/minor Install barriers to 

keep users on 

system route

X

Boca Reservoir 

“Open Area”

05175700240/CA-NEV-81* Displacement Direct/minor Install barriers to 

keep users on 

system routes

X

Boca Reservoir 

“Open Area”

CA-NEV-26 Displacement Direct/moderate Site is below high 

water in closed BOR 

area. Demarcate

closed area.

X

Boca Reservoir 

“Open Area”

05175700747 Displacement Direct/moderate Install barriers X

Boca Reservoir 

“Open Area”

05175700749 Displacement Direct/moderate Install barriers X
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

556 – Tahoe National Forest

Route ID Site Number Effect Type/Severity Protection Measure Alt 2

Boca Reservoir 

“Open Area”

05175700750 Displacement Direct/moderate Install barriers X

Boca Reservoir 

“Open Area”

05175700775 Displacement Direct/moderate Install barriers X

Boca Reservoir 

“Open Area”

05175700776 Displacement Direct/moderate Install barriers X

Boca Reservoir 

“Open Area”

05175700777 Displacement Direct/moderate Install barriers X

Prosser Reservoir 

“Open Area”

05175700609 Displacement/

shoreline 

erosion

Direct/moderate Install barriers X

Prosser Reservoir 

“Open Area”

05175700608/CA-NEV-64 Displacement/

shoreline 

erosion

Direct/moderate Install barriers X

Prosser Reservoir 

“Open Area”

05175700753 Displacement Direct/moderate Install barriers X

Prosser Reservoir 

“Open Area”

05175700754 Displacement Direct/moderate Install barriers X

Prosser Reservoir 

“Open Area”

05175700755 Displacement Direct/moderate Install barriers X

Prosser Reservoir 

“Open Area”

05175700756 Displacement Direct/minor Install barriers X

Prosser Reservoir 

“Open Area”

05175700757 Displacement Direct/moderate Install barriers X

Prosser Reservoir 

“Open Area”

05175700758 Displacement Direct/moderate Install barriers X

Prosser Reservoir 

“Open Area”

05175700759 Displacement Direct/moderate Install barriers X

Prosser Reservoir 

“Open Area”

05175700760 Displacement Direct/moderate Install barriers X

Prosser Reservoir 

“Open Area”

05175700761 Displacement Direct/moderate Install barriers X

Prosser Reservoir 

“Open Area”

05175700762 Displacement Direct/moderate Install barriers X

Stampede Reservoir 

“Open Area”

05175700535 Displacement Direct/moderate Install barriers to 

keep users on route

X

Stampede Reservoir 

“Open Area”

05175700540 Displacement Direct/moderate Install barriers to 

keep users on route

X

Stampede Reservoir 

“Open Area”

05175700004/SIE-S44 Displacement/

shoreline 

erosion/looting

Direct/minor Install barriers X

Stampede Reservoir 

“Open Area”

05175700763 Displacement Direct/moderate Install barriers X

Stampede Reservoir 

“Open Area”

05175700764 Displacement Direct/moderate Install barriers X

Stampede Reservoir 

“Open Area”

05175700765 Displacement Direct/moderate Install barriers X

Stampede Reservoir 

“Open Area”

05175700766 Displacement Direct/moderate Install barriers X
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

Tahoe National Forest – 557

Route ID Site Number Effect Type/Severity Protection Measure Alt 2

Stampede Reservoir 

“Open Area”

05175700767 Displacement Direct/moderate Install barriers X

Stampede Reservoir 

“Open Area”

05175700768 Displacement Direct/moderate Install barriers X

Stampede Reservoir 

“Open Area”

05175700769 Displacement Direct/moderate Install barriers X

Stampede Reservoir 

“Open Area”

05175700770 Displacement Direct/moderate Install barriers X

Stampede Reservoir 

“Open Area”

DWR-S-1 Unknown-below 

waterline

Unknown N/A X

Stampede Reservoir 

“Open Area”

SIE-11 Unknown-below 

waterline

Unknown N/A X

Stampede Reservoir 

“Open Area”

SIE-12 Unknown-below 

waterline

Unknown N/A X

Stampede Reservoir 

“Open Area”

SIE-13 Unknown-below 

waterline

Unknown N/A X

Stampede Reservoir 

“Open Area”

SIE-14 Unknown-below 

waterline

Unknown N/A X

Stampede Reservoir 

“Open Area”

SIE-15 Unknown-below 

waterline

Unknown N/A X

Stampede Reservoir 

“Open Area”

SIE-16 Unknown-below 

waterline

Unknown N/A X

Stampede Reservoir 

“Open Area”

SIE-17 Unknown-below 

waterline

Unknown N/A X

D_25_d 05175300004 Displacement Direct/minor Monitor X

D_11E03_b 05175300016* Displacement/

Camping

Direct/minor Monitor X

D_11E03_c 05175300016* Displacement/

Camping

Direct/minor Monitor X

D_11E03_d 05175300016* Displacement/

Camping

Direct/minor Monitor X

D_721-2_a 05175300074 Displacement/

Camping

Direct/minor Monitor X

D_12E66_c 05175300156* Camping Direct/minor Monitor X

D_12E66_d 05175300156* Camping Direct/minor Monitor X

D_S-301_a 05175300176 Camping Direct/minor Monitor X

D_S-301_a 05175300188 Camping Direct/minor Monitor X

D_11E10_a 05175300386 None None Monitor X

D_12E66_a 05175300404* Camping Direct/minor Monitor X

D_12E66_a 05175300561* Camping Direct/minor Monitor X

D_12E67_d 05175300404* Camping Direct/minor Monitor X

D_12E67_d 05175300561* Camping Direct/minor Monitor X

D_S295_a 05175300436* Camping Direct/minor Monitor X

D_S295_b 05175300436* Camping Direct/minor Monitor X

D_12E68_a 05175300455 Camping Direct/minor Monitor X

D_S300_a 05175300595* Camping Direct/minor Monitor X

D_S300_b 05175300595* Camping Direct/minor Monitor X
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

558 – Tahoe National Forest

Route ID Site Number Effect Type/Severity Protection Measure Alt 2

D_738-4_a 05175300883 Camping Direct/minor Monitor X

D_12E66_b 05175300892 Camping Direct/minor Monitor X

D_P88_b 05175400312 Camping Direct/minor Monitor X

D_14_b 05175500105* Camping Direct/minor Monitor X

D_14_j 05175500105* Camping Direct/minor Monitor X

D_18-19_a 05175500344 Camping Direct/minor Monitor X

D_03-4_a 05175700148 Camping Direct/minor Monitor X

D_886-10_a 05175700379* Camping Direct/minor Monitor X

D_886-18_a 05175700379* Camping Direct/minor Monitor X

D_886-18_b 05175700379* Camping Direct/minor Monitor X

D_450-101_a 05175700779 Camping Direct/minor Monitor X

SV-P14 05175600571 Displacement Direct/minor Install barriers to 

keep users on route

X

TKN-J11 05175700096 Camping None None X

TKN-J13 05175700286 Displacement/

shoreline 

erosion

Direct/moderate Install barriers X

TKN-J13 05175700287 Displacement/

shoreline 

erosion

Direct/moderate Install barriers X

TKN-J6 05175700374 Displacement/

camping

Direct/minor Recreation mitigation 

protects site.

X

TKN-M2 05175700395 Displacement Direct/minor Install barriers to 

keep users on route

X

TKN-M2 05175700397 Displacement Direct/minor Install barriers to 

keep users on route

X

TKN-M2 05175700734 Erosion/

Displacement

Direct/moderate Install barriers to 

keep users on routeWatershed and 

botany mitigations 

will help protect site.

X

TKN-Q1 05175700087 Displacement Direct/minor Monitor X

TKS-11 05175700735 None None None X

TKS-11 05175700736 None None Monitor X

YRN-004 05175300676 Displacement Direct/minor Monitor X

YRN-007 05175300426 None None Monitor X

YRN-008 05175300369 Displacement/

rutting

Direct/moderate Install barriers to 

keep users on route 

and to designated 

camping areas.

X

YRN-1 05175300881 None None Monitor X

YRN-2 05175300499 Erosion Direct/moderate Monitor-. X

YRN-2 05175300545 Displacement Direct/minor Install barriers to 

keep users on route

X

YRN-2 05175300546 None None Monitor X

YRN-4 05175300386 None None Monitor X

YRN-7 05175300674 Erosion Direct/moderate Monitor- X
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

Tahoe National Forest – 559

Route ID Site Number Effect Type/Severity Protection Measure Alt 2

YRN-M2 05175300671 Erosion Direct/moderate Monitor X

YRN-M2 05175300675 Displacement Direct/minor Monitor X

YRN-M2 05175300890 None None Monitor X

YRS-SF5 05175500272 None None Monitor X

Note: * indicates a site associated with multiple routes once but only counted once.

Alternative 3: Cross Country Travel Prohibition Only – No Changes to the Existing 

National Forest Transportation System

Alternative 3 would prohibit cross country travel and proposes no new additions to the NFTS. This 

alternative also provides a baseline for comparing the impacts of other alternatives that propose changes 

to the NFTS. None of the unauthorized roads, trails, or areas would be added to the NFTS. Alternative 3

responds to the issues of transportation system management costs, potential adverse effects of motorized 

roads and trails on the characteristics of Inventoried Roadless Areas, quiet recreation and potential 

adverse impacts associated with motorized roads and trails on water, soils, sensitive plants, wildlife, and 

cultural resources. 

Direct and Indirect Effects

Under Alternative 3, cross country travel is prohibited, no unauthorized motorized routes would be added 

to the system, and no changes made to the existing NFTS. No cultural resource sites would be directly or 

indirectly affected. There would be beneficial effects to cultural resources under this alternative. There are 

a minimum of 882 cultural resources sites identified associated with unauthorized routes. These sites are 

at risk from ongoing use. Based on the effects identified during monitoring for this undertaking, these 

effects would not continue under this alternative.

To quantify potential cumulative effects, one can calculate the average number of previously 

identified cultural resource sites per acre that would be at risk. Within the TNF, 3,228 cultural resources 

sites have been identified. Site density averages .004 cultural resource sites for every acre. Excluding the 

133 cultural resource sites identified (Table 3.05-5) within the APE, upwards of 3,095 additional cultural 

resource sites would not be susceptible to an adverse effect because cross country travel would prohibited,

and no unauthorized motorized routes would be added to the existing NFTS and no “Open Areas” would 

be established.

Alternative 4: Increased Resource Protection

Alternative 4 responds to issues of cost, maintenance, wilderness, Inventoried Roadless Areas, quiet use, 

and natural resource impacts by prohibiting cross country travel and adding fewer routes to the NFTS 

than the Proposed Action. Alternative 4 is based on the Proposed Action contained in the Notice of Intent 

as modified by an alternative submitted by an environmental group coalition during scoping.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

560 – Tahoe National Forest

Direct and Indirect Effects

Under Alternative 4, cross country travel is prohibited and a total of 26.3 miles of unauthorized motorized 

routes (3.7 miles of road and 22.6 miles of trail) would be added to the Forest transportation system.

There are 16 sites within the APE for this alternative (4 sites are associated with multiple routes; they are 

noted in Table 3.05-13 with an *).

Additions to the NFTS: Two (2) routes have direct effect/moderate severity ratings to two sites 

located on a proposed route along the shoreline of Stampede Reservoir. They are also subjected to 

shoreline erosion. Barriers would be installed to keep motorized users on the designated route. Thirteen

(13) sites have direct/minor effects. Monitoring at these sites is prescribed as many of the effects were 

negligible and difficult to determine (i.e., camping at an extremely large basalt quarry area). The type and 

severity of effects for the remaining 1 site is “none”. Sites determined ineligible were removed from Table 

3.05-13.

Reopening Maintenance Level 1 roads: There are no cultural resources associated with the 

proposed opening of the Maintenance Level 1 road.

Table 3.05-13. Summary of Effects to Cultural Resources at Risk: Alternative 4

Route ID Site Number Effect Type/Severity Protection Measure Alt 4

D_25_d 05175300004 Displacement Direct/minor Monitor- X

D_721-2_a 05175300074 Displacement/Camping Direct/minor Monitor X

D_12E66_c 05175300156* Camping Direct/minor Monitor X

D_12E66_d 05175300156* Camping Direct/minor Monitor X

D_S-301_a 05175300176 Camping Direct/minor Monitor X

D_S-301_a 05175300188 Camping Direct/minor Monitor X

D_S295_a 05175300436* Camping Direct/minor Monitor X

D_S295_b 05175300436* Camping Direct/minor Monitor X

D_12E68_a 05175300455 Camping Direct/minor Monitor X

D_S300_a 05175300595* Camping Direct/minor Monitor X

D_S300_b 05175300595* Camping Direct/minor Monitor X

D_P88_b 05175400312 Camping Direct/minor Monitor X

D_14_b 05175500105* Camping Direct/minor Monitor X

D_14_j 05175500105* Camping Direct/minor Monitor X

D_18-19_a 05175500344 Camping Direct/minor Monitor X

D_03-4_a 05175700148 Camping Direct/minor Monitor X

SV-P14 05175600571 Displacement Direct/minor Install barriers to keep 

users on route

X

TKN-J13 05175700286 Displacement/shoreline 

erosion

Direct/moderate Install barriers X

TKN-J13 05175700287 Displacement/shoreline 

erosion

Direct/moderate Install barriers X

YRS-SF5 05175500272 None None Monitor X

Note: * indicates a site listed multiple times but only counted once.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

Tahoe National Forest – 561

Alternative 5: Increased Motorized Recreation Access plus Reopening 

Maintenance Level 1 and Temporary Roads

Alternative 5 is based on the Proposed Action contained in the Notice of Intent as modified by an 

alternative submitted by the Blue Ribbon Coalition during the scoping process. Alternative 5 was 

developed to address the issue of providing sufficient wheeled motorized public access to TNF lands as 

well as public concerns about reduced motorized recreation opportunities.

Direct and Indirect Effects

Under Alternative 5, cross country travel is prohibited and a total of 80.4 miles of unauthorized motorized 

routes (5 miles of roads and 75.4 miles of trails) would be added to the Forest transportation system.

There are a total of 77 sites within the APE for this alternative (15 sites are associated with multiple 

routes; they are noted in Table 3.05-14 with an *).

Additions to the NFTS: Sixty (60) sites have a direct/minor rating, 7 have a direct/moderate rating,

and 10 have a “none” rating (these totals include the 19 cultural resources associated with reopening 

Maintenance Level 1 roads; these are noted in the table with ML 1 under the Route ID column). Of the 7

sites with moderate effect, the use of low impact barriers would reduce or eliminate the effects or the 

implementation of watershed, botany or recreation mitigations (i.e., barriers) would further protect the 

site. At Site 05175300217, there is an ongoing looting situation at this site. Law enforcement is actively 

patrolling this location. Monitoring is prescribed at many of the sites as effects were negligible and 

difficult to determine. Sites determined ineligible were not included in the table (Table 3.05-14).

Reopening Maintenance Level 1 roads There are 19 cultural resources associated with the proposal 

to reopen Maintenance Level 1 roads (routes are noted in Table 3.05-14 with the notation ML 1). With the 

exception of 2 sites, effects were negligible and difficult to determine at these sites since current use is 

sporadic. Monitoring will provide for adaptive management if effects change with increased use. This is a 

management option in the Motorized Recreation PA. There are two sites associated with the proposal to 

reopen a Maintenance Level 1 road (Route YRN-509) and the prescribed protection measure is to install 

barriers to prohibit unauthorized motorized use on the spur roads that access the sites.

Table 3.05-14. Summary of Effects to Cultural Resources at Risk: Alternative 5

Route ID Site Number Effect Type/Severity Protection 

Measure

Alt 5

25-9_p (ML 1) 05175300469 Displacement Direct/minor Monitor X

491-3_1 05175300337 None None Monitor X

491-3_2 05175300216 Displacement Direct/minor Monitor X

H11E10 05175300696 Displacement Direct/minor Monitor X

H301-6 (ML 1) 05175300176* Displacement Direct/minor Monitor X

H301-6 (ML 1) 05175300188* Displacement Direct/minor Monitor X

H3-4-4 (ML 1) 05175700148* Displacement Direct/minor Monitor X

H54-9 (ML 1) 05175600283 Displacement Direct/minor Monitor X

H54-9 (ML 1) 05175600341 Displacement Direct/minor Monitor X

H54-9 (ML 1) 05175600317 Displacement Direct/minor Monitor X
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

562 – Tahoe National Forest

Route ID Site Number Effect Type/Severity Protection 

Measure

Alt 5

H88-44 (ML 1) 05175400215 Displacement Direct/minor Monitor X

H889-28 05175700088 Displacement Direct/minor Monitor X

H889-3-18-5 (ML 1) 05175700563* Displacement Direct/minor Monitor X

H889-8 05175700395* Displacement Direct/minor Monitor X

H889-8 05175700401 Displacement Direct/minor Monitor X

H894-5-1 05175700240/CA-NEV-81 Displacement Direct/minor Monitor X

N25-1-1 (ML 1) 05175300347 Displacement Direct/minor Monitor X

N25-1-1 (ML 1) 05175300348 Displacement Direct/minor Monitor X

N25-2 (ML 1) 05175300454 Displacement Direct/minor Monitor X

N25-6-1 (ML 1) 05175300356 Displacement Direct/minor Monitor X

N25-7 (ML 1) 05175300034 Displacement Direct/minor Monitor X

N261-8-15-2 05175700563* Displacement Direct/minor Monitor X

N27-3 (ML 1) 05175300514 Displacement Direct/minor Monitor X

N27-5 (ML 1) 05175300446 Displacement Direct/minor Monitor X

N39-5 (ML 1) 05175300217 Displacement/looting Direct/minor Monitor X

N43-6-2 05175400368 Displacement Direct/minor Monitor X

N860-20-1 05175600426 Displacement Direct/minor Monitor X

N860-20-1 05175700540 Displacement Direct/minor Monitor X

N886-14-10 05175700577 Displacement Direct/minor Monitor X

N886-1-5 05175700009 Displacement Direct/minor Monitor X

N886-1-5 05175700409 Displacement Direct/minor Monitor X

N886-18-10 05175700447 Displacement Direct/minor Monitor X

N886-18-10 05175700529 Displacement Direct/minor Monitor X

N889-3-30-10 05175700304 Displacement Direct/minor Monitor X

N890-14-5 05175700511 Displacement Direct/minor Monitor X

N96-34-2-6 05175400325 Displacement Direct/minor Monitor X

D_25_d 05175300004 Displacement Direct/minor Monitor- X

D_11E03_b 05175300016* Displacement/Camping Direct/minor Monitor X

D_11E03_c 05175300016* Displacement/Camping Direct/minor Monitor X

D_11E03_d 05175300016* Displacement/Camping Direct/minor Monitor X

D_721-2_a 05175300074 Displacement/Camping Direct/minor Monitor X

D_12E66_c 05175300156* Camping Direct/minor Monitor X

D_12E66_d 05175300156* Camping Direct/minor Monitor X

D_S-301_a 05175300176* Camping Direct/minor Monitor X

D_S-301_a 05175300188* Camping Direct/minor Monitor X

D_11E10_a 05175300386* None None Monitor X

D_12E66_a 05175300404* Camping Direct/minor Monitor X

D_12E66_a 05175300561* Camping Direct/minor Monitor X

D_12E67_d 05175300404* Camping Direct/minor Monitor X

D_12E67_d 05175300561* Camping Direct/minor Monitor X

D_S295_a 05175300436* Camping Direct/minor Monitor X
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

Tahoe National Forest – 563

Route ID Site Number Effect Type/Severity Protection 

Measure

Alt 5

D_S295_b 05175300436* Camping Direct/minor Monitor X

D_12E68_a 05175300455 Camping Direct/minor Monitor X

D_S300_a 05175300595* Camping Direct/minor Monitor X

D_S300_b 05175300595* Camping Direct/minor Monitor X

D_738-4_a 05175300883 Camping Direct/minor Monitor X

D_12E66_b 05175300892 Camping Direct/minor Monitor X

D_P88_b 05175400312 Camping Direct/minor Monitor X

D_14_b 05175500105* Camping Direct/minor Monitor X

D_14_j 05175500105* Camping Direct/minor Monitor X

D_18-19_a 05175500344 Camping Direct/minor Monitor X

D_738-4_f 05175500363* Camping Direct/minor Monitor X

D_738-4_g 05175500363* Camping Direct/minor Monitor X

D_738-4_e 05175500364 Camping Direct/minor Monitor X

D_03-4_a 05175700148* Camping Direct/minor Monitor X

D_886-10_a 05175700379* Camping Direct/minor Monitor X

D_886-18_a 05175700379* Camping Direct/minor Monitor X

D_886-18_b 05175700379* Camping Direct/minor Monitor X

D_450-101_a 05175700779 Camping Direct/minor Monitor X

SV-P14 05175600571 Displacement Direct/minor Install barriers 

to keep users 

on route

X

TKN-J11 05175700096 Camping None None X

TKN-J13 05175700286 Displacement/shoreline 

erosion

Direct/moderate Install barriers X

TKN-J13 05175700287 Displacement/shoreline 

erosion

Direct/moderate Install barriers X

TKN-J6 05175700374 Displacement/camping Direct/minor Recreation 

mitigation 

protects site.

X

TKN-M2 05175700395* Displacement Direct/minor Install barriers 

to keep users 

on route

X

TKN-M2 05175700397 Displacement Direct/minor Install barriers 

to keep users 

on route

X

TKN-M2 05175700734 Erosion/

Displacement

Direct/moderate Install barriers 

to keep users 

on route. 

Watershed and 

botany 

mitigations will 

help protect 

site.

X

TKN-Q1 05175700087 Displacement Direct/minor Monitor X

TKS-11 05175700735 None None None X

TKS-11 05175700736 None None Monitor X

YRN-004 05175300676 Displacement Direct/minor Monitor X
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

564 – Tahoe National Forest

Route ID Site Number Effect Type/Severity Protection 

Measure

Alt 5

YRN-007 05175300426 None None Monitor X

YRN-008 05175300369 Displacment/

rutting

Direct/moderate Install barriers 

to keep users 

on route and to 

designated 

camping areas.

X

YRN-1 05175300881 None None Monitor X

YRN-2 05175300499 Erosion Direct/moderate Monitorwatershed 

mitigations will 

protect site 

from erosion.

X

YRN-2 05175300545 Displacement Direct/minor Install barriers 

to keep users 

on route

X

YRN-2 05175300546 None None Monitor X

YRN-4 05175300386* None None Monitor X

YRN-509

(ML 1)

05175300198 Displacement Direct/minor Install barriers 

to prohibit use 

on spur road off 

main route

X

YRN-509

(ML 1)

05175300205 Displacement Direct/minor Install barriers 

to prohibit use 

on spur road off 

main route

X

YRN-7 05175300674 Erosion Direct/moderate Monitorwatershed 

mitigations will 

protect site 

from erosion.

X

YRN-M2 05175300671 Erosion Direct/moderate Monitorwatershed 

mitigations will 

protect site 

from erosion.

X

YRN-M2 05175300675 Displacement Direct/minor Monitor X

YRN-M2 05175300890 None None Monitor X

YRS-SF5 05175500272 None None Monitor X

Note: * indicates a site listed multiple times but only counted once.

Alternative 6: Preferred Alternative Motorized Access and Resource Protection

Alternative 6 is the Preferred Alternative. It responds to issues of providing motorized public access and 

recreation opportunities while minimizing impacts to natural resources. It is designed to provide a 

diversity of road and trail opportunities for experiencing a variety of environments and modes of travel 

consistent with the National Forest’s recreation role and land capability. Alternative 6 would provide

motorized access to dispersed recreation opportunities and a diversity of motorized recreation 

opportunities. 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

Tahoe National Forest – 565

Direct and Indirect Effects

Under Alternative 6, cross country travel would be prohibited and a total of 61.4 miles of unauthorized 

motorized routes (13.1 miles of road and 48.3 miles of trail) would be added to the Forest transportation 

system. Additionally, three motorized “Open Areas” would be established for a total of 244 acres (Boca 

Reservoir, Prosser Reservoir, and Stampede Reservoir). There are 59 sites within the APE for this 

alternative (12 sites are associated with multiple routes; they are noted in Table 3.05-15 with an *).

Additions to the NFTS: Forty-five (45) sites have a rating of direct/minor, 5 sites have a rating of 

direct/moderate, and 9 have a rating of “none” (these include the three sites associated with the proposal 

to reopen Maintenance Level 1 roads). Of the 5 sites with moderate effect, the use of low impact barriers 

would reduce or eliminate effects or the implementation of watershed, botany or recreation mitigations 

(i.e., barriers) would further protect the site. At Site 05175400008, there is an ongoing looting situation; 

law enforcement is actively patrolling this location. The district is considering installing interpretive 

signage. Monitoring is prescribed at many of the sites as effects were negligible and difficult to 

determine. Sites determined ineligible were not included in the table (Table 3.05-15).

Establishment of Motorized “Open Areas”: There are no cultural resources located within the 

proposed 244 acres of “Open Areas.” These specific areas are located at Boca, Prosser, and Stampede 

Reservoirs at the end of existing NFTS roads. They would provide shoreline access for motorized 

vehicles as water levels shrink throughout the year.

Reopening Maintenance Level 1 roads: There are three sites associated with the proposal to reopen 

Maintenance Level 1 roads (routes are noted in Table 3.05-15 with the notation ML 1). For route YRN509, the protection measure is to install barriers to prohibit unauthorized motorized use on the spur roads 

that access the sites. For route 25-9_p, the protection measure is to monitor. Monitoring will provide for 

adaptive management if effects change with increased use. This is a management option in the Motorized 

Recreation PA.

Table 3.05.15. Summary of Effects to Cultural Resources at Risk: Alternative 6

Route ID Site Number Effect Type/Severity Protection Measure Alt 6

25-9_p

(ML 1)

05175300469 Displacement Direct/minor Monitor X

491-3_1 05175300337 None None Monitor X

D_25_d 05175300004 Displacement Direct/minor Monitor X

D_11E03_b 05175300016* Displacement/Camping Direct/minor Monitor X

D_11E03_c 05175300016* Displacement/Camping Direct/minor Monitor X

D_11E03_d 05175300016* Displacement/Camping Direct/minor Monitor X

D_721-2_a 05175300074 Displacement/Camping Direct/minor Monitor X

D_12E66_c 05175300156* Camping Direct/minor Monitor X

D_12E66_d 05175300156* Camping Direct/minor Monitor X

D_S-301_a 05175300176 Camping Direct/minor Monitor X

D_S-301_a 05175300188 Camping Direct/minor Monitor X

D_11E10_a 05175300386* None None Monitor X
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

566 – Tahoe National Forest

Route ID Site Number Effect Type/Severity Protection Measure Alt 6

D_12E66_a 05175300404* Camping Direct/minor Monitor X

D_12E66_a 05175300561* Camping Direct/minor Monitor X

D_12E67_d 05175300404* Camping Direct/minor Monitor X

D_12E67_d 05175300561* Camping Direct/minor Monitor X

D_S295_a 05175300436* Camping Direct/minor Monitor X

D_S295_b 05175300436* Camping Direct/minor Monitor X

D_12E68_a 05175300455 Camping Direct/minor Monitor X

D_S300_a 05175300595* Camping Direct/minor Monitor X

D_S300_b 05175300595* Camping Direct/minor Monitor X

D_738-4_a 05175300883 Camping Direct/minor Monitor X

D_12E66_b 05175300892 Camping Direct/minor Monitor X

D_6149-31 05175400008 Camping/looting Direct/minor Monitor X

D_P88_d 05175400176 None None Monitor X

D_P88_b 05175400312 Camping Direct/minor Monitor X

D_14_b 05175500105* Camping Direct/minor Monitor X

D_14_c 05175500105* Camping Direct/minor Monitor X

D_14_h 05175500105* Camping Direct/minor Monitor X

D_14_j 05175500105* Camping Direct/minor Monitor X

D_14-4 05175500105* Camping Direct/minor Monitor X

D_18-19_a 05175500344 Camping Direct/minor Monitor X

D_738-4_f 05175500363* Camping Direct/minor Monitor X

D_738-4_g 05175500363* Camping Direct/minor Monitor X

D_738-4_e 05175500364 Camping Direct/minor Monitor X

D_5_b 05175600018 Camping Direct/minor Monitor X

D_16TH19-1 05175600119 Camping Direct/minor Monitor X

D_7-10 05175600164 Camping Direct/minor Monitor X

D_860-42 05175600202 Camping Direct/minor Monitor X

D_S450 05175600338 Camping Direct/minor Monitor X

D_5_a 05175600394 Camping Direct/minor Monitor X

D_860-25 05175600421 Camping Direct/minor Monitor X

D_SV-M1 05175600431 Camping Direct/minor Monitor X

D_560-20_b 05175600442 Camping Direct/minor Monitor X

D_03-4_a 05175700148 Camping Direct/minor Monitor X

D_270-8_b 05175700358* Camping Direct/minor Monitor X

D_270-8_c 05175700358* Camping Direct/minor Monitor X

D_886-10_a 05175700379* Camping Direct/minor Monitor X

D_886-18_a 05175700379* Camping Direct/minor Monitor X

D_886-18_b 05175700379* Camping Direct/minor Monitor X

D_S860_a 05175700620 Camping Direct/minor Monitor X

D_787-19 05175700756 Camping Direct/minor Monitor X

D_450-101_a 05175700779 Camping Direct/minor Monitor X

D_860-5_i 05175700096* Camping None None X
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

Tahoe National Forest – 567

Route ID Site Number Effect Type/Severity Protection Measure Alt 6

D_N886_18C 05175700778 Camping Direct/minor Monitor X

SV-P14 05175600571 Displacement Direct/minor Install barriers to keep users 

on route

X

TKN-J11 05175700096* Camping None None X

TKN-J13 05175700286 Displacement/shoreline 

erosion

Direct/moderate Install barriers X

TKN-J13 05175700287 Displacement/shoreline 

erosion

Direct/moderate Install barriers X

TKN-J6 05175700374 Displacement/camping Direct/minor Recreation mitigation protects 

site.

X

TKN-M2 05175700395 Displacement Direct/minor Install barriers to keep users 

on route

X

TKN-M2 05175700397 Displacement Direct/minor Install barriers to keep users 

on route

X

TKN-M2 05175700734 Erosion/

Displacement

Direct/moderate Install barriers to keep users 

on route-Watershed and 

botany mitigations will help 

protect site.

X

TKN-Q1 05175700087 Displacement Direct/minor Monitor X

TKN-PP 05175700774 Displacement Direct/minor Monitor X

TKS-11 05175700735 None None None X

TKS-11 05175700736 None None Monitor X

YRN-008 05175300369 Displacement/

rutting

Direct/moderate Install barriers to keep users 

on route and to designated 

camping areas.

X

YRN-1 05175300881 None None Monitor X

YRN-2 05175300499 Erosion Direct/moderate Monitor-watershed mitigations 

will protect site from erosion.

X

YRN-2 05175300545 Displacement Direct/minor Install barriers to keep users 

on route

X

YRN-2 05175300546 None None Monitor X

YRN-4 05175300386* None None Monitor X

YRN-509

(ML 1)

05175300198 Displacement Direct/minor Install barriers to prohibit use 

on the spur road off main route

X

YRN-509

(ML 1)

05175300205 Displacement Direct/minor Install barriers to prohibit use 

on the spur road off main route

X

YRS-SF5 05175500272 None None Monitor X

Note: * indicates a site listed multiple times but only counted once.

Alternative 7: Proposed Action as Identified in Notice of Intent (NOI)

Alternative 7 is the Proposed Action as published in the Notice of Intent in the Federal Register.

Direct and Indirect Effects

Under Alternative 7, cross country travel is prohibited and a total of 36.7 miles of unauthorized motorized 

routes (trails) would be added to the Forest transportation system. There are 13 sites within the APE for 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

568 – Tahoe National Forest

this alternative. There are no sites in this alternative associated with multiple routes.

Additions to the NFTS: Three (3) sites have a rating of direct/minor, 4 sites have a rating of 

direct/moderate, and 6 have a rating of “none” (Table 3.05-16). Of the 4 sites with moderate effect, the 

use of low impact barriers would reduce or eliminate the effects or the implementation of watershed, 

botany or recreation mitigations (barriers) would protect the site. Monitoring is prescribed at many of the 

sites as effects were negligible and difficult to determine. Sites determined ineligible were not included in 

the table. 

Reopening Maintenance Level 1 roads: There are no cultural resources sites associated with the 2 

ML 1 roads totaling 1.1 miles that would be opened under Alternative 7.

Table 3.05.16. Summary of Effects to Cultural Resources at Risk: Alternative 7

Route ID Site Number Site Type NRHP 

Status

Effect Type/Severity Protection 

Measure

Alt 7

SV-P14 05175600571 Prehistoric Unevaluated Displacement Direct/minor Install 

barriers to 

keep users 

on route

X

TKN-J13 05175700286 Multi Unevaluated Displacement/shoreline 

erosion

Direct/moderate Install 

barriers

X

TKN-J13 05175700287 Prehistoric Unevaluated Displacement/shoreline 

erosion

Direct/moderate Install 

barriers

X

TKN-J6 05175700374 Prehistoric Unevaluated Displacement/camping Direct/minor Recreation 

mitigation 

barriers

X

TKS-11 05175700735 Prehistoric Unevaluated None None None X

TKS-11 05175700736 Prehistoric Unevaluated None None Monitor X

YRN-1 05175300881 Historic Unevaluated None None Monitor X

YRN-2 05175300499 Historic Unevaluated Erosion Direct/moderate Monitor X

YRN-2 05175300545 Historic Unevaluated Displacement Direct/minor Install 

barriers to 

keep users 

on route

X

YRN-2 05175300546 Historic Unevaluated None None Monitor X

YRN-4 05175300386 Historic Unevaluated None None Monitor X

YRN-7 05175300674 Historic Unevaluated Erosion Direct/moderate Monitor X

YRS-SF5 05175500272 Historic Unevaluated None None Monitor X

Cumulative Effects

The geographic scope of the cumulative effects analysis is limited to the Forest’s administrative boundary 

(836,041 acres) because impacts to cultural resources accumulate at their specific locations, irrespective 

of actions in surrounding areas. 

Alternative 1 would allow cross country travel to continue. Alternative 1, when combined with the 

past, present and foreseeable future actions (see Appendix H), is expected to cumulatively lead to 

increased impacts to cultural resources. 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

Tahoe National Forest – 569

The data reported in Table 3.05-11 demonstrate that the No Action Alternative would have 

unmitigated, long-term adverse effects on cultural resources. A minimum of 133 cultural resource sites

would be adversely affected if no mitigation action was taken. Another 749 sites identified with other 

unauthorized routes not added to the NFTS under an alternative could potentially be affected in the 

absence of any long-term management actions or oversight; therefore, at least 882 cultural resource sites 

could be subject to adverse effects in the APE.

To quantify potential cumulative effects, one can calculate the average number of previously 

identified cultural resource sites per acre that would be susceptible to new routes created in the future 

without a prohibition. Within the TNF, 3,228 cultural resources sites have been identified. Site density 

averages .004 cultural resource sites for every acre. Excluding the 133 cultural resource sites that have 

already been identified (Table 3.05-5) within the APE, upwards of 3,095 additional cultural resource sites

could be susceptible to an adverse effect if no management actions were implemented.

Alternative 2 has 85 cultural resource sites identified as resources at risk within the APE due to the 

cumulative effects of adding routes to the NFTS, and establishing “Open Areas.” The 68 sites that have 

minor or moderate effects would be monitored or mitigated to reduce the effects.

Alternative 3 has no cultural resource sites identified as resources at risk within the APE due to no 

changes to the current NFTS. 

Alternative 4 has 16 cultural resource sites identified as resources at risk within the APE due to the 

cumulative effects of adding routes to the NFTS. The 15 sites that have minor or moderate effects would 

be monitored or mitigated to reduce the effects.

Alternative 5 has 77 cultural resource sites identified as resources at risk within the APE due to the 

cumulative effects of adding routes to the NFTS and reopening ML 1 roads. The 67 sites that have minor 

or moderate effects would be monitored or mitigated to reduce the effects.

Alternative 6 has 59 cultural resource sites identified as resources at risk within the APE due to the 

cumulative effects of adding routes to the NFTS, establishing “Open Areas,” and reopening ML 1 roads. 

The 50 sites that have minor or moderate effects would be monitored or mitigated to reduce the effects.

Alternative 7 has 13 cultural resource sites identified as resources at risk within the APE due to the 

cumulative effects of adding routes to the NFTS and reopening ML 1 roads. The 7 sites that have minor or 

moderate effects would be monitored or mitigated to reduce the effects.

Cross country travel would be halted under the action alternatives. The prohibition of cross country 

travel would simplify enforcement by prohibiting any motorized use off NFTS roads, trails, and “Open 

Areas”. As a result, cumulative effects would be diminished under all action alternatives. Alternatives 2-7, 

when combined with prohibiting cross country, and the past, present and foreseeable future actions (see 

Appendix H), are expected to cumulatively lead to reduced impacts to cultural resources. At least 882

cultural resource sites would be protected from adverse effects.

Unregulated cross country travel, as occurring under the No Action Alternative, has the greatest 

potential for creating adverse effects to cultural resources making the route designation process an 

important part of preventing long-term effects to these resources.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.05. Cultural Resources

570 – Tahoe National Forest

Summary of Effects Analysis across All Alternatives

This section summarizes the effects analysis by discussing how well each alternative addresses the 

cultural resources for each measurement indicator. The following ranks were used in Table 3.05-17 that 

follows: A score of 7 indicates the alternative has the least impact for cultural resources; a score of 1 

indicates the alternative has the most impact for cultural resources.

Table 3.05-17. Comparison of Effects to Cultural Resources

Indicators – Cultural Resources Rankings of Alternatives for Each Indicator*

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Degree to which the integrity of cultural resource values are 

diminished

1 3 7 5 2 4 6

Number of cultural resources within unauthorized routes at 

risk from ongoing use

1 2 7 5 4 3 6

Average number of cultural resources per acre protected 

from creation of new routes 

1 2 7 5 4 3 6

Average for Cultural Resources 1 2 7 5 4 3 6

* A score of 7 indicates the alternative has the least impact for this resource; a score of 1 indicates the alternative has the most 

impact.

Compliance with the Forest Plan and Other Direction

Alternatives 2, 3, 4, 5, 6, and 7 comply with all Forest Plan S&Gs as well as with all federal laws 

identified in the Analysis Framework Section. Alternative 1 does not comply with Forest Plan S&Gs or 

with the federal laws identified in the Analysis Framework Section.
Chapter 3.06 

Plant Communities 

Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Tahoe National Forest – 571

3.06. Plant Communities__________________________________

Introduction

Management of plant/fungi species, native plant communities, and maintenance of plant diversity, is an 

important part of the mission of the Forest Service (FS) (Resource Planning Act of 1974, National Forest 

Management Act of 1976). Management activities on National Forest System (NFS) lands must be 

planned and implemented so that they do not jeopardize the continued existence of threatened or 

endangered species or lead to a trend toward listing or loss of viability of FS Sensitive species. In 

addition, management activities should be designed to maintain or improve habitat for rare plants and 

natural communities to the degree consistent with multiple-use objectives established in each Forest Land 

and Resource Management Plan (LRMP). Key parts include: developing and implementing management 

practices to ensure that species do not become threatened or endangered because of FS actions; 

maintaining viable populations of all native and desired non-native wildlife, fish, and plant species in 

habitats distributed throughout their geographic range on National Forest System (NFS) lands, and 

developing and implementing management objectives for populations and/or habitats of rare species.

Management decisions related to motorized travel can affect plant and fungi species, their habitats, 

and natural communities. The FS provides a process and standard through which rare plants receive full 

consideration throughout the planning process, reducing negative impacts on species and enhancing 

opportunities for mitigation by developing and implementing management objectives for populations 

and/or habitats of sensitive species. It is FS policy to minimize damage to soils and vegetation, avoid 

harassment to wildlife, and avoid significant disruption of wildlife habitat while providing for motorized 

public use on NFS lands (FSM 2353.03(2)). Therefore, management decisions related to motorized travel 

on NFS lands must consider effects to plant and fungi species, and their habitats.

Analysis Framework: Statute, Regulation, Forest Plan

and Other Direction

Direction relevant to the Proposed Action as it affects native plants/plant communities includes:

Endangered Species Act (ESA): The ESA of 1973 (16 USC 1531 et seq.) requires that any action 

authorized by a federal agency not be likely to jeopardize the continued existence of a threatened or 

endangered (TE) species, or result in the destruction or adverse modification of habitat of such species 

that is determined to be critical. Section 7 of the ESA, as amended, requires the responsible federal 

agency to consult the USFWS and the National Marine Fisheries Service concerning TE species under 

their jurisdiction. It is FS policy to analyze impacts to TE species to ensure management activities are not 

likely to jeopardize the continued existence of a TE species, or result in the destruction or adverse 

modification of habitat of such species that is determined to be critical. This assessment is documented in 

a Biological Assessment (BA) and is summarized or referenced in this chapter.

E.O. 13112 Invasive Species 64 FR 6183 (February 8, 1999): To prevent and control the 

introduction and spread of invasive species.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

572 – Tahoe National Forest

Forest Service Manual and Handbooks (FSM/H 2670): Forest Service Sensitive (FSS) species are 

plant species identified by the Regional Forester for which population viability is a concern. The Forest 

Service develops and implements management practices to ensure that rare plants and animals do not 

become threatened or endangered and ensure their continued viability on national forests. It is Forest

Service policy to analyze impacts to sensitive species to ensure management activities do not create a 

significant trend toward federal listing or loss of viability. This assessment is documented in a Biological 

Evaluation (BE) and is summarized or referenced in this Chapter.

Sierra Nevada Forest Plan Amendment (SNFPA): The Record of Decision (ROD) for the 2004 

Sierra Nevada Forest Plan Amendment identified the following direction applicable to motorized travel 

management and botanical resources:

• Noxious weeds management (Management Standard & Guidelines 36-49).

• Wetland and Meadow Habitat (Management Standard & Guideline 70): See Appendix I (Riparian 

Conservation Objectives).

• Riparian Habitat (Management Standard & Guideline 92): See Water Resources section.

• Bog and Fen Habitat (SNFPA ROD page 65, S&G #118): Prohibit or mitigate ground-disturbing 

activities that adversely affect hydrologic processes that maintain water flow, water quality, or 

water temperature critical to sustaining bog and fen ecosystems and plant species that depend on 

these ecosystems. During project analysis, survey, map, and develop measures to protect bogs and 

fens from such activities as trampling by livestock, pack stock, humans, and wheeled vehicles. 

• Sensitive Plant Surveys (Corrected Errata, April 19, 2005): Conduct field surveys for threatened, 

endangered, proposed, and sensitive (TEPS) plant species early enough in project planning 

process that the project can be designed to conserve or enhance TEPS plants and their habitat.

Conduct surveys according to procedures outlined in the Forest Service Handbook (FSH 

2609.25.11). If additional field surveys are to be conducted as part of project implementation, 

survey results must be documented in the project file. (Management Standard & Guideline 125).

The standards and guidelines provide direction for conducting field surveys, minimizing or 

eliminating direct and indirect impacts from management activities, and adherence to the 

Regional Native Plant Policy (USDA Forest Service 2004).

In addition, the Tahoe National Forest (TNF) has completed interim management guides (IMGs) for 

several sensitive species including: Eriogonum umbellatum var. torreyanum (1993); Ivesia aperta var. 

aperta, Ivesia aperta var. canina, and Ivesia sericoleuca (1992); and Lewisia cantelovii and Lewisia 

serrata (1997). The most commonly recommended management prescription in these IMGs is avoidance 

of direct, indirect and cumulative impacts.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

Tahoe National Forest – 573

Affected Environment

Background

TNF plant communities are made up of a series of vegetation types arranged in dynamic patterns. TNF 

plant communities are constantly changing due to the occurrence of such things as: wildfires, ecological 

succession, climate change, wind, drought, insects, management activities, etc.

As described in the SNFPA (2001), the physical structures that form the TNF and the diversity and 

number of plant species, have not changed much in the last 2 million years. However, the distribution and 

associations of plant species have changed significantly over time. Table 3.06-1 provides the acres and 

types of vegetation types found on the TNF (SNFPA 2001).

The difference between the current distribution and abundance of rare plant (threatened, endangered, 

proposed, sensitive, and/or watchlist) populations and historic levels is largely unknown (SNFPA 2001). 

Plant species may be rare due to evolutionary history, basic population ecology, historic or current human 

activities, or a combination of these factors. Human activities may or may not be responsible for the 

current distribution and abundance of rare species. However, an important assumption in this analysis is 

that motorized vehicle use within and adjacent to rare species occurrences have the ability to negatively 

impact the trends of specific plant and fungi species. In particular, motorized vehicle use can reduce the 

quality of and/or the amount of habitats that support rare plant and fungi species. Table 3.06-2 displays 

the number of sensitive species occurrences known to occur on TNF system lands.

In addition to rare plant species, six of the native plant communities found in the TNF are impacted 

by motorized vehicle use: aquatic/riparian, serpentine, older forests, oak woodland, forest edges/openings, 

and high elevation openings/rocky areas. Two ecologically important disturbance related processes that 

are contributed to by motorized vehicle use are also discussed in detail: noxious weed infestation and 

native plant community fragmentation.

Aquatic/riparian, serpentine, older forest, oak woodland, forest edges/openings, and high elevation 

openings/rocky area plant communities are made up of several different vegetation types. These plant 

communities are of concern because of the amount of the plant community available, the condition of the 

remaining plant communities, and/or because the plant community provides habitat for a number of 

threatened, endangered, proposed, sensitive, (TEPS) and/or watchlist plants. The presence of and 

expansion of weeds into Sierra Nevada native plant communities is a serious threat to all plant 

communities. In addition, the lack of connectivity/fragmentation of plant communities is a concern.
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Table 3.06-1. Acres of Vegetation Type on the TNF

Vegetation type Acres

Unvegetated (includes rock outcrops, water, urban and agricultural) 50,159

Grassland (does not include grassy patches in the conifer zones) 34

Shrublands (does not include brush patches embedded in the conifer zone) 165,409

Black oak 50,306

Live oak 9,518

Riparian hardwoods (primarily aspen, willow and cottonwood species) 3,559

Mixed conifer 164,693

Ponderosa pine 11,645

Red fir 127,388

Westside white fir 174,455

The diversity of topography, geology, and elevation on the TNF has combined to create conditions 

that support a diverse flora. For example, the TNF is known to contain about 30 percent of the 5,000 

native vascular plant species known to occur in the state of California. In Nevada County alone, there are 

over 1,490 native vascular plant species (Beedy and Brossard 2002). The TNF sensitive species list 

currently contains 30 rare vascular plants that are known to occur on or near TNF system lands. They 

include: Arabis rigidissima var. demota, Astragalus webberi, Botrychium ascendens, Botrychium 

crenulatum, Botrychium lunaria, Botrychium minganense, Botrychium montanum, Calochortus clavatus

var. avius, Clarkia biloba ssp. Brandegeae, Cypripedium fasciculatum, Cypripedium montanum, 

Epilobium howellii, Erigeron miser, Eriogonum umbellatum var. torreyanum, Fritillaria eastwoodiae, 

Ivesia aperta var. aperta, Ivesia aperta var. canina, Ivesia sericoleuca, Ivesia webberi, Lewisia cantelovii, 

Lewisia kelloggii ssp. hutchisonii, Lewisia kelloggii ssp. kelloggii, Lewisia longipetala, Lewisia serrata, 

Lupinus dalesiae, Monardella follettii, Penstemon personatus, Phacelia stebbinsii, Pyrrocoma lucida, and

Tauschia howellii. These 30 plants, 6 mosses, 1 lichen, and 3 fungi are listed in Table 3.06-2. The TNF 

also has 21 vascular plants on its watchlist.

There are 6 rare mosses known to occur on TNF system lands and/or adjacent to them. They include: 

Bruchia bolanderi, Fissidens aphelotaxifolius, Helodium blandowii, Meesia triquetra, Meesia uliginosa, 

and Mielichhoferia elongata. These mosses are habitat specific either occurring in aquatic/riparian areas 

or in rock with copper/heavy metals (Mielichhoferia elongata). They may have crucial roles in the 

hydrologic cycle and in the ecology of meadows and riparian areas. The TNF does not have a 

comprehensive moss flora. In addition, Meesia longiseta and Sphagnum moss species are included on the 

TNF watchlist. It is possible that Meesia longiseta occurs in fens on the TNF but at this time there are no 

known occurrences of Meesia longiseta on the TNF. Several fen habitats on the TNF are known to contain 

mosses in the genus Sphagnum. Sphagnum moss is ecologically important in that it prefers to grow in 

acidic conditions and actually contributes to the acidity by giving off hydrogen ions. In addition, 

Sphagnum moss can absorb more than 90 percent of its dry weight in water, which can be crucial in 

maintaining hydrological conditions in meadows and fens.
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Motorized vehicles impact moss species in several ways. When mosses are run over by vehicles, they 

do not have an underground root system that can help them recover (compared to vascular plants). In 

addition, water temperature is important to the photosynthetic ability of mosses. As described in the 

SNFPA (2001) mosses can photosynthesize effectively at temperatures as low as 33 degrees F (compared 

to a lower limit of about 50 degrees F for vascular plants). Mosses stop photosynthesizing effectively at 

an upper limit of about 77 degrees F (in contrast to vascular plants, some of which can photosynthesize at 

temperatures of up to 100 degrees F). When moss layers are disturbed by vehicles, it is possible that water 

temperatures can go up due to hydrologic disruption.

The rare lichen, Hydrothyria venosa, is known to occur on or near TNF system lands. There are no 

lichens on the TNF watchlist. Lichens occur in all types of habitats, and frequently show specific 

substrate preferences. They are important in soil formation. Information regarding lichen distributions in 

the Sierra Nevada and on the TNF is incomplete. There is a great need for further study of lichen ecology 

and distribution in the Sierra Nevada. Motorized vehicle use affects lichens primarily through damage to 

the organisms themselves and by damaging the habitat where they are growing. Threats to Hydrothyria 

venosa include damage to the habitat component of clear water from introduction of sediment and 

possibly petroleum products.

There are 3 rare fungi known to occur on or adjacent to TNF system lands. They include: Cudonia 

monticola, Dendrocollybia racemosa, and Phaeocollybia olivacea. There are no fungi on the TNF 

watchlist. Information regarding fungal distributions and ecology on the TNF is incomplete. However, it 

is known that fungi break down organic material to make inorganic nutrients available for use by other 

organisms. In addition, many fungi are considered essential food sources for animals. Others play 

important roles as mycorrhizal symbionts for vascular plants where nutrients are exchanged between a 

fungus and the roots of a plant. Motorized vehicle use affects fungi primarily through damage to the 

underground portion of the fungus through compaction and/or displacement of soil, and/or damage to 

and/or displacement of host plants. Mycorrhizal relationships between fungi and vascular plants are 

essential for plant growth and survival. Motorized vehicles are recognized as carriers of non-native 

invasive plants (weeds) that can displace native vegetation.

Motorized vehicle use is also known to damage biotic (living) soil crusts. These soil crusts are formed 

from a relationship between the top few millimeters of the soil, and an assortment of lichens, mosses, 

liverworts, cyanobacteria, algae, fungi, and bacteria. Motorized vehicles break through these crusts 

exposing the soil to wind and/or water erosion.

Table 3.06-2. Number of Sensitive Species Occurrences Known to Occur on TNF System Lands

Scientific Name Known Occurrences 

on TNF system lands

Estimated number of plants

Arabis rigidissima var. demota None 0

Astragalus webberi None 0

Botrychium ascendens 4 Less than 80

Botrychium crenulatum 8 Less than 500

Botrychium lunaria None 0
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Scientific Name Known Occurrences 

on TNF system lands

Estimated number of plants

Botrychium minganense None 0

Botrychium montanum None 0

Bruchia bolanderi 4 Number of moss plants not estimated

Calochortus clavatus var. avius None 0

Clarkia biloba ssp. Brandegeae 4 Varies by year – this is an annual plant – less than 4,000

Cudonia monticola 1 Not estimated – most of the fungus is underground.

Cypripedium fasciculatum 5 Less than 500

Cypripedium montanum None 0

Dendrocollybia racemosa 1 Not estimated

Epilobium howellii 4 Less than 500

Erigeron miser 14 8,100

Eriogonum umbellatum var. 

torreyanum

11 7,000

Fissidens aphelotaxifolius None 0

Fritillaria eastwoodiae 7 Less than 1,000

Helodium blandowii None 0

Hydrothyria venosa None 0

Ivesia aperta var. aperta 5 Less than 5,000

Ivesia aperta var. canina None 0

Ivesia sericoleuca 28 50,000

Ivesia webberi None None

Lewisia cantelovii 16 Less than 5,000

Lewisia kelloggii ssp. 

hutchisonii

8 10,000+

Lewisia kelloggii ssp. kelloggii None 0

Lewisia longipetala 4 Less than 1,000

Lewisia serrata 5 Less than 500

Lupinus dalesiae 2 Less than 500

Meesia triquetra 12 Number of moss plants not estimated.

Meesia uliginosa 17 Number of moss plants not estimated.

Mielichhoferia elongata None 0

Monardella follettii None 0

Penstemon personatus 2 Less than 1,000

Phacelia stebbinsii 19 Varies by year – this is an annual plant

Phaeocollybia olivacea 2 Not estimated – most of the fungus is underground.

Pyrrocoma lucida 12 Less than 25,000

Tauschia howellii 2 Less than 5,000

Plant Community Groups

Background: The following discussion groups TNF rare plants and fungi by the general types of habitats 

where they grow and/or places them into a non-specific plant community group. The plant community/ 
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habitat grouping approach is not all inclusive. Important habitat elements necessary to the viability of a 

particular species may be missed. However, this grouping provides a rough approximation of the type of 

habitat each species needs and allows an evaluation of how the potential habitat is impacted by motorized 

vehicle use. An evaluation of how potential habitat is impacted is important since surveys are not 

considered up to date, especially along temporary and Management Level 1 (ML 1) roads. Unauthorized

and system motorized vehicle roads/trails/areas may or may not have sensitive and/or watchlist species 

growing within or adjacent to them. However, it is reasonable to expect them to be in the potential habitat 

since there are known occurrences of sensitive/watchlist species and/or watchlist plant communities 

within and/or near NFTS roads/trails/areas.

Mitigation measures specified in Appendix A (Site Specific Road, Trail and Open Area Information) 

would be implemented in all of the action alternatives (they become management requirements). These 

mitigation measures would provide benefits to sensitive/watchlist species and other native vegetation. All 

of the mitigation measures must be implemented before the motorized road/trail/area is available to be 

used. Regardless of which action alternative is selected, there would be benefits to native vegetation from 

implementation of these mitigation measures. However, impacts to native vegetation would still occur.

These impacts are not considered significant unless those impacts are reducing the viability of a species or 

causing the loss of an entire plant community. Therefore, this analysis focuses on impacts to those 

plant/fungus species and/or plant communities that are considered limited, i.e. the sensitive/watchlist 

species and watchlist plant communities. The analysis is divided into the effects of impacts to known 

occurrences where surveys have been done, and effects to potential habitats where current surveys are not 

available.

Revegetation of unauthorized roads/trails/areas (routes): The amount of time necessary for an 

unauthorized road/trail/area (route) to revegetate is a concern primarily due to possible sediment loss 

through erosion and changes to the hydrology. The appearance of native vegetation in a disturbed area is 

considered one of the first visual signs of ecosystem recovery (Switalski et al. 2004). Vegetative recovery 

of sites is considered acceptable once an herbaceous understory of native vegetation is achieved (Gibson 

et al. 2000). Studies of the length of time it takes a disturbed area to achieve vegetative recovery indicate 

that the amount of time varies, and that extrapolation of the time frames from one site to another requires

an accounting of site-specific historical and environmental factors (ibid). In addition, the limiting factors 

of the disturbed area (e.g. seed availability, plant recruitment and survival, and soil compaction) need to 

be defined (Roovers et al. 2005).

Rare plants/fungi and plant communities may continue to be negatively impacted by unauthorized 

routes for a period of time even after the motorized use is removed if erosion from the unauthorized

motorized vehicle is not reduced and/or eliminated and hydrologic flow is not restored. It is recognized 

that continued use of routes in need of erosion control by other users (foot, mountain bike and horse 

traffic) may also prohibit vegetative recovery. Native vegetative cover protects against erosion and 

maintains infiltration capacity of the soil (Switalski et al. 2004). Soil and watershed surveys of 

unauthorized motorized vehicle routes indicate 50% of the routes had some level of erosion. Refer to the 

botanical and soil/water survey documentation located in the project record. Therefore, it is important to 
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estimate how long it might take an unauthorized motorized vehicle route to recover vegetatively once the 

motorized vehicle use is removed.

It is anticipated that some of the unauthorized motorized vehicle routes will not recover without 

restoration actions. These routes would be restored by the TNF as budgets and personnel are available. 

Some unauthorized routes may be proposed for addition to the NFTS at a later date after conducting 

NEPA and implementing mitigations to reduce and/or eliminate existing resource damage. Other routes 

may be used for non-motorized recreation. Still others would be left alone and they will revegetate 

without restoration actions. All of these scenarios add to and/or reduce impacts to native vegetation. As 

stated above, it is recognized that non-motorized recreational use may also negatively impact native 

vegetation. However, motorized vehicle use is recognized as more damaging to vegetation than 

pedestrians (USDA et al. 1998). In addition, the rate of vegetative recovery of any unauthorized route will 

vary from site to site based on the soil type, amount and type of vegetative cover at the site, topography of 

the area disturbed, and intensity of the motorized vehicle use (USDA et al. 1998). The ecological effects 

of motorized vehicle routes can extend substantial distances from the road in terrestrial ecosystems 

(Trombulak and Frissell 2000). Motorized vehicle routes can injure organisms adjacent to them and alter 

physical conditions beneath them. They change soil density, temperature, soil water content, light levels, 

dust, surface waters, patterns or runoff and sedimentation. They can also add heavy metals (especially 

lead), salts, organic molecules, ozone, and nutrients to adjacent environments (ibid).

Aquatic/Riparian Plant Communities

Riparian vegetation is found near water sources at all elevations, and aquatic vegetation is found within 

the water. The SNFPA (2004) identified special aquatic features and defined them as unique wetlands of 

high biological diversity occupied by rare aquatic and terrestrial animal plant species. Aquatic and 

riparian ecosystems have significantly greater biodiversity than adjacent uplands (Kondolf et al. 1996), 

providing habitat for both aquatic and terrestrial plant and animal species. They are a critical component 

of biodiversity within the arid lands of the western United States and their importance is amplified by the 

small amount of land they occupy (Caicco 1998, Goebel et al. 2003). These ecosystems are also important 

for rare or endemic plant and animal species including rare or endemic invertebrate species (Erman 1996, 

Erman and Erman 1990).

Riparian plant communities are important even though they may cover only small areas. Some small 

riparian plant communities (those associated with streams and wetlands such as springs and seeps) are 

considered headwater systems. Headwater systems benefit humans by mitigating flooding, maintaining 

water quality and quantity, recycling nutrients, and providing habitat for plants and animals (Meyer et al 

2003). The benefits that humans receive from the natural functioning of headwater systems are called 

ecosystem services. Intact physical and biological characteristics of small streams and wetlands provide 

natural flood control, recharge groundwater, trap sediments and pollution from fertilizers, recycle 

nutrients, create/maintain biological diversity, and sustain the biological productivity of downstream 

rivers, lakes and estuaries. Seasonal and perennial riparian and aquatic ecosystems provide these 

ecosystem services. Human disturbances such as extensive motorized vehicle use within headwater 
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systems can result in water pollution, stream filling, and/or the introduction of weeds and other exotic 

species, can diminish the biological diversity of the systems, and affect the downstream rivers and 

streams (ibid). Changes to vegetation or hydrology, water pollution, or the introduction of weeds can have 

profound effects on biota living in headwaters (ibid).

Most estimates indicate that more than 50 percent of the world’s aquatic/riparian plant communities 

(wetlands) may have been altered, degraded or lost in the last 150 years through a wide range of human 

activities (O’Connell 2003). Aquatic/riparian plant communities in the Sierra Nevada have been directly 

removed or have had their functions impaired by gold mining, gravel mining, hydroelectric development, 

land clearance and diversions of water for irrigation, land drainage, timber harvest, construction of roads 

and railroads, urbanization, livestock grazing, and ground water abstraction (Kondolf et al. 1996). Many 

of the NFTS and unauthorized motorized vehicle routes cross perennial/intermittent streams and/or are 

located within 100 feet of aquatic/riparian plant communities. 

This analysis used 100 feet from riparian vegetation to define the distance where direct/indirect 

impacts from motorized vehicles could occur. This distance has been successfully used in other projects to 

buffer native plants/plant communities from direct/indirect impacts. TNF soil/water staff has also used a 

100-foot buffer for perennial water to reduce/eliminate impacts from a variety of projects (to protect 

water quality from negative impacts from other types of management activities). A recent review of 

scientific literature revealed that a 100-foot riparian buffer is adequate to mitigate against significantly 

impacting riparian and aquatic resources (Spackman and Hughes 1995 and Steinblums, I. J., H. A. 

Froehlich, and J. K. Lyons, 1984).

About 541 miles of motorized vehicle use are currently located within 100 feet of riparian vegetation 

on the TNF (about 395 miles of NFTS, state, county, and private, and 146 miles of unauthorized routes

and closed NFTS roads still receiving some motorized use). A distance of one vehicle length from

aquatic/riparian dependent rare plants was chosen as the distance from a route where motorized vehicle 

use could directly impact rare plants. The Tahoe has about 3,389 perennial and intermittent water 

crossings (NFTS, state, county, and private and unauthorized). According to information presented in 

Section 3.02, the condition of system routes varies - with areas of high motorized route density and high 

erosion risk having a higher risk of accelerated erosion and sediment production and/or deposition. 

Section 3.02 states that - in general, higher route densities translate into higher potential for adverse 

effects to aquatic/riparian habitats.

In this analysis, aquatic/riparian plant communities have been grouped to include: wet meadows, 

seeps, fens/peatlands, vernally wet areas, riparian (streamside and lakeside), wet/moist rock cliffs, and 

spring plant communities. Sensitive species that occur in/are dependent on aquatic/riparian plant 

communities include: Botrychium ascendens, Botrychium crenulatum, Botrychium lunaria, Botrychium 

minganense, Botrychium montanum, Bruchia bolanderi, Epilobium howellii, Fissidens aphelotaxifolius, 

Helodium blandowii, Hydrothyria venosa, Ivesia aperta var. aperta, Ivesia aperta var. canina, Ivesia 

sericoleuca, Ivesia webberi, Lewisia cantelovii, Lewisia serrata, Meesia triquetra, Meesia uliginosa, and 

Pyrrocoma lucida. Watchlist plants and plant communities that are dependent on aquatic/riparian plant 

communities include: Darlingtonia californica, Drosera anglica, Drosera rotundifolia, Juncus 
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marginatus var. marginatus, Mimulus lacinatus, Potamogeton filiformis, Rhynchospora alba, 

Rhynchospora capitellata, Scutellaria galericulata, Sphagnum moss species, Utricularia minor, Veronica 

cusickii, special aquatic features, and aspen groves. Bruchia bolanderi was found within 30 feet of TKNJ5. Ivesia sericoleuca was found within 1 foot of TKN-M2. Epilobium howellii was found at the end of 

YRN-001. A vernal pool was found adjacent to TKN-J2. Aspen plant communities were found along 

TKN-J11, TKN-J13, TKN-M2, TKS-11, SV-005, and SV-P14. Seep/spring plant communities were found 

along SV-005, TKN-5, TKN-J13, TKN-M2, YRS-066, YRS-SF4 and YRS-SF5.

Hydrologic alteration is considered one of the biggest threats to sensitive/watchlist species dependent 

on aquatic/riparian plant communities. Many NFTS and unauthorized motorized vehicle routes cross 

perennial and/or intermittent streams and/or are located within 100 feet of riparian vegetation. These 

crossings can alter the hydrologic conditions of the aquatic/riparian plant community at the crossing and 

downstream from the crossing. The significance of the hydrologic alterations (and therefore impacts to 

aquatic/riparian vegetation) is dependent on the condition of the soil and vegetation at the crossing. 

Surveys of crossings (refer to the project record) showed a wide range of existing conditions. Some 

crossings are well armored with rock and do not show significant signs of erosion (or impacts to 

aquatic/riparian vegetation). In other cases, the access to the crossing is too steep, erosion of the stream 

banks is occurring and/or riparian vegetation is lacking. Refer to Appendix A (Site Specific Road, Trail 

and Open Area Information) for more information about crossings. 

In summary, sensitive/watchlist species dependent on aquatic/riparian plant communities benefit most 

when the health of the aquatic/riparian ecosystem is maintained or improved. Motorized vehicle use can 

negatively impact these plant communities by changing the pattern of water flow, reducing vegetative 

cover, compacting soil, causing erosion, depositing petroleum products/sediment thereby reducing water 

quality, and introducing invasive non-native plants (weeds). The significance of these negative impacts 

varies dependent on many factors.

Riparian vegetative recovery: Native riparian vegetation is adept at recovering from disturbance 

such as motorized vehicle use as long as the soil is healthy (healthy soil is not compacted or lost through 

erosion) and the hydrology of the disturbed area is not severely modified. However, each riparian site is 

different - for example, each stream has a unique combination of channel morphology, streamside 

vegetation, hydrology, geology, and soils. Therefore the recovery rates of riparian vegetation will vary. 

Routes located adjacent to streams and groundwater discharge areas (seeps and springs) will be 

susceptible to excessive wetness and periodic flooding (Leung and Marion 1996) and may continue to 

erode even after the motorized use is removed. The presence of weeds indicates a degrading ecosystem 

(Thompson et al 1998). Routes with extensive weed infestation may not recover vegetatively.

Light use: If the motorized vehicle disturbance was light (bare soil was not created/is limited, the 

route is already revegetating, and/or streambanks and floodplains were not significantly altered), 

vegetative recovery will occur rapidly (1 to 2 years based on personal observations) since the roots of the

riparian vegetation will still be intact. Native riparian tree and shrub species have deep rooted, soil 

binding root systems. If native tree and shrub root systems are intact, species such as white or mountain 

alder (Alnus rhombifolia and A. tenuifolia) will sprout from the root crown and grow throughout the first 
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growing season after the disturbance. Native rhizomatous riparian species such as sedges (Carex species) 

will also continue to grow and provide soil cover if their root systems have not been significantly 

disturbed.

Heavy use: Heavily used riparian areas will have reduced infiltration due to soil compaction, and 

subsequent surface runoff; reduced and/or eliminated vegetative cover; and the streams and floodplains 

may have been physically modified. If restoration actions are not taken, erosion may continue and worsen 

dependent on many factors such as storm and high peak runoff events. In the case of riparian vegetation 

associated with streams, where a channel is beginning a cycle of erosion, native riparian vegetation seed 

sources may be absent, the channel gradients may be steep and recovery may require decades or longer 

(Elmore and Beschta 1987). These areas may not recover without restoration efforts and would be high 

priority restoration project areas.

Riparian vegetation associated with meadows can heal when remedial treatments reverse the 

downward trend in the following indicators (Zeedyk 1996): 

• Incised channel with active headward erosion

• Eroding soil surface marked by sheet, rill or gully erosion, lowered water table and receding 

capillary zone

• Surface drying with loss of hydric soils

• Declining population of wetland plant species

• Increasing numbers of upland species

• Disappearance of wetland obligate fauna

Restoration of wet meadow areas begins when available soil moisture increases and the duration of 

moisture availability is extended enough to meet the minimum seasonal growth requirements of locally 

adapted wetland plants, especially sedges and rushes (Zeedyk 1996). Allowing unauthorized routes

located within wet meadows to heal themselves is seldom a responsible decision with regard to restoring 

wetland integrity (Zeedyk 1996). The route surface must be reshaped to allow overland runoff to cross 

over rather than be captured by the unauthorized route. Simple revegetation is seldom sufficient to assure 

meadow restoration - structural work is usually required (ibid). This is especially true where the 

unauthorized route has incised below the meadow surface.

Riparian vegetation recovery in disturbed areas located in fen/peatland/spring/seep areas would be 

similar to what is described above under light and/or heavy use. However, if fen plant communities are 

heavily disturbed and the hydrology altered, the fen plant community may be converted to a wet meadow 

plant community. Fens/peatlands contain plant species adapted to specific conditions. Therefore there 

would be a change in plant species composition and a change in plant biodiversity for the area.

Intermediate use: In areas that have received intermediate use, the existing condition of riparian 

vegetation impacted by unauthorized motorized vehicle routes falls somewhere between being able to 

recover on its own, and needing extensive restoration work. Riparian vegetation located within one 

vehicle length of an unauthorized motorized vehicle route will need site specific evaluation to determine 

what is needed for revegetation, and monitoring to determine whether vegetative recovery is occurring. 
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The greater soil moisture in riparian plant communities magnifies the amount of plant and soil damage 

(Yorks et al 1997).

Serpentine and/or Copper/Heavy Metal Plant Communities

Serpentines (ultramafic soils) are looked upon as significant segments of the worldwide fabric of diversity 

(Kruckeberg 1984). The vegetation growing on serpentine areas can be highly distinctive. Many 

serpentine areas are sparsely vegetated and dry, while others are relatively productive and support mixed 

conifer and yellow pine communities. Plants that exist on serpentine soil have adapted to the unusual 

chemical composition of the soil. Many species have evolved that are specific to serpentine soil (such 

species are known as endemics). Several endemic serpentine sensitive and watchlist plant species only 

occur on serpentine soil. Currently there are about 1,660 acres of serpentine soils on TNF system lands 

that are impacted by motorized vehicle use of system and unauthorized roads/trails/areas (within 100 feet 

of the road/trail/area). There are 80 miles of NFTS, state, county, and private and 40 miles of 

unauthorized routes and closed NFTS roads still receiving some motorized use located within serpentine 

plant communities.

Serpentines are also identified as irreplaceable watershed systems (Kruckeberg 1984). Serpentine 

outcrops contain highly fractured and faulted metamorphic and igneous ultramafic rock which serves to 

store water in the water table. Year-around water such as springs, seeps, and other continuous water flow 

areas are common in these areas (ibid). Even undisturbed serpentine areas may have sheet erosion and 

mass wasting. However, disturbance severely enhances the erosion potential on serpentines (ibid).

In this analysis, serpentine plant communities include rocks and soils derived from serpentine that 

contain heavy metals. Serpentine rocks have iron magnesium silicate and impurities of chromium, nickel, 

and other toxic elements. As these rocks weather, soils develop that are high in magnesium and iron, low 

in calcium, and toxic to plants that are not specifically adapted to them. Therefore, they contain unique 

plant communities. Sensitive species that occur on serpentine soils or copper/heavy metal soils include: 

Mielichhoferia elongata and Monardella follettii. Watchlist species that are dependent on these types of 

habitats include: Allium sanbornii var. congdonii, Allium sanbornii var. sanbornii, Chlorogalum 

grandiflorum, and Perideridia bacigalupi. Many serpentine floras in California contain a high degree of 

endemism (Brooks 1987). TNF serpentines occur primarily along the lower western slopes of the forest 

(Kruckeberg 1984).

Motorized vehicle use impacts these plant communities by reducing vegetative cover, creating 

disturbed soils that are subject to erosion, and introducing weeds. Many serpentine habitats are open 

terrain lacking vegetation (Kruckeberg 1984). These habitats are limited (less than 1 percent of the earth) 

(Brooks 1987).

Serpentine vegetative recovery: Serpentine areas are characterized by critically low levels of most 

principal plant nutrients, exceptionally high levels of magnesium and iron, and a number of toxic trace 

elements (Safford et al. 2005). Safford and Harrison (2005) report that very low soil fertility in serpentine 

soils lead to:

• low rates of plant growth and low levels of community productivity
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• thin vegetative cover and large extents of bare ground

• higher ratios of native to exotic species

• a higher component of perennial herbs than the adjacent nonserpentine areas

Human disturbance in serpentine areas such as off-highway vehicle use are generally easy to see 

because vegetation and soil recovery are very slow (Harrison et al 2006). Revegetation of serpentine areas 

disturbed by motorized vehicle use may also be dependent on whether topsoil remains in the disturbed 

area. In one study (Koide and Mooney 1987), revegetation of topsoil plots was much more effective than 

revegetation efforts on subsoil plots especially in serpentine areas with shallow soils. In another study, 

older trees harvested on serpentine soils were not replaced by old second growth trees for more than 150 

years (Kruckeberg 1984). In addition, the types of plants that are capable of growing on serpentine soils 

appear to be limited (ibid). Many of the plants that are growing on non-serpentine soils located adjacent to 

serpentine soils do not appear to have the genetic preadaptation to become established on serpentine soils 

(ibid).

Since even undisturbed serpentine areas are considered erosive, it is expected that revegetation of 

unauthorized motorized vehicle routes would be slow especially if the use level was intermediate to heavy 

and there was a loss of top soil. Even lightly disturbed areas would have increased erosion potential. 

Therefore, in general terms, vegetative recovery of unauthorized motorized vehicle routes is not expected 

in the short term (1 to 5 years) and may not occur in the long term (5 years plus) without restoration 

efforts.

Older Forest Plant Communities

In this analysis, older forest is described as occurring in the red fir/upper montane forest and mixedconifer forest. Other vegetation types exist that also have older trees, but mixed conifer and red fir are the 

primary types of older forest analyzed in this document. For more information about old forests, refer to 

the SNFPA (2001). There are about 285,728 acres of older forest on TNF system lands, of which 29,900 

acres are currently, impacted by system and unauthorized, motorized vehicle roads/trails/areas (routes).

This acreage number was obtained using about 100 feet on either side of system and unauthorized

motorized vehicle routes that pass through vegetation mapped as CWHR 4 and above on NFS lands. 

There are about 2,057 miles of NFTS, state, county, and private and 817 miles of unauthorized routes and 

closed NFTS roads still receiving some motorized use located in older forest plant communities.

Plant and fungi species that are dependent on older forest plant communities rely on shade, protected 

microclimates, and infrequently disturbed substrates. Because of mycorrhizal associations, these species 

are intolerant of edge effects that change the temperature, moisture, and other microclimate conditions. 

Sensitive species dependent on these habitats include: Cudonia monticola, Cypripedium fasciculatum, 

Cypripedium montanum, Dendrocollybia racemosa, and Phaeocollybia olivacea. The TNF does not 

currently have any watchlist species or plant communities dependent on older forests.

Motorized vehicle use can impact older forest plant communities in several ways. The most 

significant impacts may be to underground mycelia and mycorrhizal networks. Motorized vehicle use 
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disturbs the litter/duff/soil organics, reduces soil shade/moisture, and creates openings. Openings created 

by motorized vehicle routes may be breaks in the mycelial network. Reductions in leaf litter and organic 

material in soils affects the amount of nutrients and water available to plants dependent on mycorrhizal 

associations and fungi. Creation of bare soil also increases the risk of weed introduction and spread.

Older Forest vegetative recovery: Guariguata and Dupuy (1997) found evidence of soil compaction 

in tracks of 3 out of the 4 logging roads studied 12 to 17 years after those roads were abandoned. They 

estimated recovery of tree basal area in road tracks to take at least 80 years to reach the status found in 

adjacent logged forest and that species richness could take even longer to recover. However, in this 

document, vegetative recovery is described as the amount of time to re-establish the native forb layer. The 

understory species associated with old growth, including those dependent on the litter depth and 

mycorrhizal fungi of old growth forest floors are known to grow into small openings (Lindh and Muir 

2004) such as the width of a route. In the short term (five years or less), native vegetation may establish 

on routes that have little soil compaction. It is likely that routes with moderate to heavy soil compaction 

(within the wheel tracks) would take more than 5 years to recover vegetatively (develop native forb or 

shrub cover). In many cases, native shrubs growing along the sides of the route will lean into the route. 

However, the bare soil established by the motorized vehicle would remain unvegetated and subject to 

erosion.

Oak Woodland Plant Communities

California’s oak woodlands are largely privately owned and are estimated to cover about 10 million acres 

(Ewing et al. in Bartolome and Standiford 1992). They provide shelter and food for wildlife, wood and 

fuel for humans, and feed for livestock (Jimerson and Carothers 2002). Oak woodlands contain some of 

the highest species diversity found in California native plant communities (Jimerson and others in 

Jimerson and Carothers 2002). The TNF manages about 13,886 acres oak woodland. There are about 75

miles of NFTS, state, county, and private and 23 miles of unauthorized routes and closed NFTS roads still 

receiving some motorized use located in oak woodland plant communities.

Oak woodlands have experienced extensive historic disturbance through harvest of the oaks for 

fuelwood cutting, mining timbers, domestic and commercial construction, and widespread and heavy 

livestock grazing (ibid). No other ecosystem in the Sierra Nevada has experienced more human influence 

over a longer time period than the oak woodlands (Anderson in SNFPA 2001). Threats to oak woodlands 

across the State include: urbanization, conversion to agriculture, fragmentation, low rates of regeneration, 

competition from weeds, and sudden oak death. Motorized vehicles impact these ecosystems on TNF 

lands by introducing and spreading weeds, damaging native vegetation, increasing soil erosion and 

fragmenting habitats. The TNF does not have any rare plants or fungi that are entirely dependent on oak 

woodlands.

Oak woodland vegetative recovery: It is believed that oak woodlands are not regenerating in a 

sustainable fashion (McCreary 2004). The natural regeneration of some oak species is apparently 

inadequate to replace trees that are harvested or die naturally (Bartolome et al in McCreary 2004). 

Therefore, unauthorized motorized vehicle routes located in oak woodlands that are no longer used by 
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motorized vehicles may not experience a significant amount of oak regeneration. However, it is 

recognized that the best growing site for acorns is shaded, bare mineral soil (McDonald and Tappeiner in 

SNEP 1996). Acorns that fall onto the bare soil (wheel track areas) created by these routes from adjacent 

trees may have a better chance of becoming established. However, unauthorized motorized vehicle routes 

will have changed soil porosity in the wheel track areas. The moisture content of soils under the wheel 

track areas declines even if the use is removed (Helvey and Kochenderfer 1990 in Trombulak and Frissell 

2000) probably due to the changed soil porosity. In addition, the increase of sunlight to the ground in the 

motorized vehicle disturbed area may cause a change in ground cover from sparse grass to heavy grass 

and shrubs. However, the nature and rate of vegetative recovery will vary from site to site dependent on 

such factors as soil, slope, exposure to the sun and local microclimate (Johnson and Tietje – date 

unknown).

Forest Edges and Openings

Forests of all ages contain edges and openings. Plants dependent on edges and openings within forested 

plant communities are not considered habitat specific. Forest edges and openings occur in all plant 

communities. Therefore the number of acres of forested edge and openings on TNF system lands overlaps 

with the acreages in the other plant communities discussed. There are 3,489 miles of NFTS, state, county, 

and private and 1,148 miles of unauthorized routes and closed NFTS roads still receiving some motorized 

use within forest edges and opening plant communities. Forest edge and openings are constantly being 

created as trees and other vegetation dies. Forest edge and opening plant communities are lost as 

vegetation grows into them. In this analysis, sensitive species with potential habitat within forest edge and 

openings include: Astragalus webberi, Calochortus clavatus var. avius, Clarkia biloba ssp. brandegeae, 

Fritillaria eastwoodiae, Lewisia kelloggii ssp. hutchisonii, Lewisia kelloggii ssp. kelloggii, Lupinus 

dalesiae, Penstemon personatus, and Phacelia stebbinsii. Watchlist species with potential habitat within 

edge and opening plant communities include: Androsace occidentalis var. simplex, Erigeron petrophilus

var. sierrensis, and Lilium humboldtii ssp. humboldtii.

Motorized vehicle use can impact these plant communities by increasing the risk of weed introduction 

and spread, reducing plant cover, increasing erosion, reducing photosynthetic ability by covering 

vegetation with dust, changing water flow patterns, and compacting soil.

Vegetative recovery in forest edge/opening areas: Native vegetation that responds to the creation of 

an opening in the canopy (increased light to the soil and increased nutrient availability) are generally 

considered earlier succession species. The length of time it takes a disturbed area to revegetate in forest 

edge/opening areas is dependent of a number of factors. In most cases, the soil contains seeds of native 

plants that will germinate and grow within the first year assuming top soil and water are available. This 

vegetative recovery is expected irregardless of the plant community where the forest edge/opening occurs. 

For example the understory species associated with old growth, including those dependent on the litter 

depth and mycorrhizal fungi of old-growth forest floors, will grow into small openings (Lindh and Muir 

2004) as well as native shrub species located in young forest areas such as plantations (personal 

observation). Revegetation of motorized vehicle routes by native plants will begin within the first year as 
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long as the routes do not experience continued disturbance. Again, top soil and moisture will be needed 

for the native plants to survive. If the soil and hydrology of the route has been extremely altered, 

revegetation may not occur until further action is taken. The greatest species and plant losses take place in 

the first few passes by wheels. Plant and soil damage increase with the amount of weight and power 

applied (Yorks et al 1997). Greater soil moisture and/or deeper overstory shading magnify these impacts 

(ibid).

High Elevation Openings and Rocky Areas

Some plants only grow in openings at high elevations (generally 6,000 feet and above). Trees may be 

present in the area, but they do not form closed-canopy situations. The TNF manages 43,240 acres of high 

elevation openings and rocky areas. There are 54 miles of NFTS, state, county, and private and 18 miles 

of unauthorized routes and closed NFTS roads still receiving some motorized use in these plant 

communities. Sensitive species with potential habitat within these types of plant communities include: 

Arabis rigidissima var. demota, Erigeron miser, Eriogonum umbellatum var. torreyanum, Lewisia 

longipetala, and Tauschia howellii. Watchlist species that have potential habitat within these types of 

plant communities include: Asplenium trichomanes-ramosum, Claytonia megarhiza and Tonestus eximius.

Motor vehicle use is unlikely to impact certain rare plant habitats due to the steep or rocky nature of 

the surrounding terrain. However, since these habitats are generally steep and have highly erosive 

soils/rock outcrops/rocky openings when motorized vehicle use does occur near or within the habitat 

itself, damage to the habitat can be severe. The plants dependent on these plant communities do not 

appear to compete well with other vegetation. Therefore, weed introduction and/or spread is a significant 

risk. These plant communities are already subject to natural erosion and have a short growing period. Any 

disturbance increases erosion risk and can cause significant impacts to the soil and water components of 

the habitat.

Vegetative recovery in high elevation openings and rocky areas: Studies documenting the time it 

takes for a disturbed area to revegetate in high elevation, rocky areas are very limited. It is known that 

these areas have limited growing seasons and harsh conditions in regard to temperature extremes. Any 

disturbance within these habitats would disturb and/or remove vegetation and leaf litter. Due to the 

steepness of many of these habitats, disturbance would accelerate erosion. Given these factors, it is likely 

that disturbed areas would not recover on their own. This is dependent on the amount of disturbance and 

other factors. Climate factors such as heavy snow years and unchecked soil erosion can limit plant 

establishment and stop the vegetative recovery process or push it back by several decades (Willard et al.

2007).

Noxious Weeds

Sierra Nevada region biodiversity is at increased risk due to alterations in human uses, fire regimes, and 

climatic change and changes brought about by weed invasion (D’ Antonio et al. 2004). Climate changes 

may result in massive geographical shifts in locations of sites that provide environments for native plants. 

Opportunities for replacement of native species with weeds will be enhanced (Franklin 2003). In general 
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terms, the majority of TNF system lands are considered weed free, with most weed occurrences located 

along roads and/or in highly disturbed areas such as landings. The lower elevations on the westside of the 

forest currently contain the worst weed infestations (other than the musk thistle occurrence on the Truckee 

Ranger District) and provide the entry points for many weeds into the TNF, i.e. the “source” for weeds 

that are moving upslope into coniferous forests.

When an area is heavily infested with weeds, the weeds directly compete with native plants and can 

cause their local displacement. In addition, weeds can have a number of indirect effects including changes 

to: aesthetic values, biological diversity and ecosystem services (D’Antonio et al. 2004). Potential impacts 

include: alteration of disturbance regimes (including wildfire), changes in the food base for wildlife 

species, soil erosion and loss of soil carbon storage, decreases in range or forest productivity and altered 

recreational or aesthetic values (Mack et al. 2000, Di Antonio et al. 2004). They can hybridize with native 

species (ibid) altering native plant genetics.

Maintaining or improving the NFS lands requires the maintenance and improvement of the basic 

ecosystem elements of soil, water and vegetation. The stability and ecological function of natural 

wildlands depend on a diverse community of native plants (Mullin et al 2000). Native vegetation provides 

resilience against drought, flooding, minimizes erosion, promotes water infiltration and storage, along 

with providing wildlife and recreation values. Areas infested with weeds do not provide these ecosystem 

services at the same level as native vegetation. Research has shown that sites dominated by weeds have 

increased rates of soil erosion and runoff causing degradation of habitat for wildlife and native vegetation.

Once weeds become established, it is hard to get rid of them. Weeds arrived in the United States 

(many come from Eurasia) without the insects and diseases that preyed on them, and the plants that 

evolved in competition with them in their native land. Without insects, diseases, etc. to control these 

weeds, they can increase at a rapid rate.

Disturbed areas generally have more weeds than non-disturbed areas. Weeds are more likely to have 

higher leaf area and lower tissue construction costs (advantageous under high light and nutrient 

conditions) and greater phenotypic plasticity than native plants. Increased resource availability and altered 

disturbance regimes associated with human activities often differentially increase the performance of 

weeds over that of natives (Daehler 2003). Refer to Table 3.06-3 for information about the weeds known 

to occur on TNF lands.

Motorized vehicle use is known to enhance weed introduction in a number of ways (Trombulak and 

Frissell 2000) including increasing weed introduction by moving weed seed and plant parts from place-toplace in the mud/soil on their tires, and/or on the vehicle body. In addition, motorized vehicle use disturbs 

native plant communities and makes them more suitable for weed growth by reducing native plant cover. 

The disturbed areas within and adjacent to major highways, general forest roads, two-tracked nonmaintained roads, and motorcycle trails (NFTS and unauthorized-for public use) provide habitat for any 

weed seed deposited there.

Weeds are known to be spread by motorized vehicle use regardless of the season of use. Native 

vegetation is also known to be physically damaged by motorized vehicle use regardless of the season of 

use. Season of use may or may not affect the rate of spread of weeds, and/or the creation of bare soil. 
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When weeds become established in these edge areas, they provide the weed seed source for new 

occurrences of weed in the areas adjacent. When native plants are replaced by weeds, the entire 

ecosystem can be altered. For example, when motorized vehicle use introduces weeds into new areas and 

the weeds become established, the fuel pattern is frequently changed. Weeds such as Scotch and Spanish 

brooms, cheatgrass, and others, change the arrangement of vegetation, the amount of soil moisture at 

specific times of the year, the amount of fuel available to burn, and how fire behaves. In addition, 

motorized vehicle use of the various routes is known to increase the chance of ignition through engine 

sparks, sparks from friction (e.g. rock bouncing on rock), and human negligence. If a wildfire occurs in a 

weed infested area, many weeds such as cheatgrass and French/Spanish broom have the competitive edge 

over native plants when the burned area begins to revegetate. Eliminating motorized vehicles from natural 

areas is the most effective strategy for stopping the introduction of weeds into new areas (Rooney 2003).

The rate that weeds are introduced to a new area from motorized vehicle use is unknown. In one 

study, Rooney (unpublished-2003) collected mud from the undercarriage of 14 motorized vehicles. He 

found that seeds germinated from the soil collected from 4 of those vehicles. In the same study, he 

reported that each vehicle carried an average of 3.6 seeds. When he multiplied this number by the number 

of motorized vehicle user days, he estimated that about 6 million seeds were transported per vehicle per 

year in Wisconsin. Rooney predicted that over the long term, with motorized vehicles as seed dispersers, 

the fraction of roads/trails colonized by weeds would increase until all routes had reached a weed 

saturation level. This prediction was based on the lack of constant, extensive, effective surveillance of 

motorized vehicle routes. He noted that motorized vehicles are known seed carriers, that there is 

invariably a time lag between the time weeds colonize an area and when they are detected, and another 

time lag between detection and eradication efforts. He also reported that weeds are generally better 

adapted to vehicular dispersal than native species due to their small seed size, high seed production, and 

persistent seed banks. In this analysis, 100 feet was chosen to define the distance that weed seed would 

travel on tires. In reality the distance is could be greater or less than 100 feet dependent on many factors.

When native plants are replaced by weeds, the entire ecosystem can be impacted including microbial 

flora and fauna and insect pollinators, all of which contribute to normal ecosystem function. In addition, 

these disturbed areas create edges within the various plant communities where they are located. Edges are 

recognized as potential starting points for invasions of weeds into the less disturbed areas of the rest of the 

plant community such as forested areas (Pauchard and Alaback 2005). Less disturbed areas such as the 

interior of a forest are usually considered less susceptible to weed invasion because of a combination of 

factors such as competition from native species, fewer sites for seed germination, less solar radiation and 

less seed dispersal. However, weed establishment is not based on disturbance alone. When a weed seed 

source is sufficiently close to a plant community, that plant community/habitat is at increased risk of weed 

introduction and spread.

Disturbance by motorized vehicles can have long-term effects to soils and favor weed establishment. 

Motorized vehicles compact soils reducing water infiltration and accelerating erosion. They also displace 

soils and sheer off vegetative roots. If these effects are severe there can be a loss of soil productivity. 

Numerous passes by vehicles over vegetation causes the plants to die exposing the soil organic layer. The 
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loss of vegetative cover makes the soil organic layer more susceptible to erosion. Loss of vegetative cover 

and the soil organic layer reduces the ability of the soil to hold moisture. Many weed species are more 

capable of utilizing less productive soils with less soil moisture. Some weeds can also produce secondary 

chemical compounds that inhibit native plant germination and growth. These compounds also affect 

nutrient cycling rates by inhibiting soil microbial fauna activity.

Maintenance of roads/trails/areas can also spread weeds. Grading disturbs soil and competing 

vegetation, and also transports soil, and weed seeds/parts to new locations. Cleaning ditches/developing 

waterbars moves soils and creates ideal seedbeds. Seeds from equipment can be deposited in stream 

crossings and washed downstream. Mower heads can also move weed seeds/parts to new locations. This 

movement of weed seed/parts can happen at any time of the year since the seeds and parts are present in 

the soil at infested sites at all times of the year. Stockpiles of crushed aggregate can also be infested with 

weeds. When that aggregate is moved to a new location, the weeds go with it.

Another aspect of motorized vehicle use that helps to spread weeds is tied to the use of recreational 

areas and facilities, such as trailheads, campgrounds, and dispersed camping areas. These areas are 

frequently the first site on NFS lands that the motorized vehicle comes in contact with after leaving major 

highways. Therefore, they frequently receive weed seed and plant parts. These areas have constant soil 

disturbance which provides a good seedbed for any weed seed that is deposited. In addition, the users 

themselves (recreationists) can also disperse weed seeds on their clothing, footwear, and camping 

equipment. Since many campgrounds are located near riparian plant communities and riparian areas in 

campgrounds frequently have high levels of public activity, they have a higher risk of weed infestation. 

Some weeds are adapted to aquatic/riparian plant communities and rapidly become established on sites 

where soils have been disturbed, such as streambanks and crossings areas. Water can carry weed seeds 

and plant parts great distances, increasing weed spread. Aquatic weeds, such as purple loosestrife, can 

take over whole wetland ecosystems, impeding water flow and reducing the quality of wetland habitats.

Table 3.06-3. Some of the Weeds known to occur on TNF System Lands

Weed Species CDFA* California Invasive Plant Council**

Ailanthus altissima (tree-of-heaven) C Moderate

Bromus tectorum (cheatgrass) N/A High

Carduus nutans (musk thistle) A Moderate

Carduus pycnocephalus (Italian thistle) B Moderate

Centaurea diffusa (diffuse knapweed) A Moderate

Centaurea maculosa (spotted knapweed) A High

Centaurea solstitialis (Yellow star thistle) C High

Centaurea melitensis (tocalote or Malta star thistle) C Moderate

Chondrilla juncea (skeleton weed) A Moderate

Cirsium arvense (Canada thistle) B Moderate

Cirsium vulgare (bull thistle) C Moderate

Cytisus scoparius (Scotch broom) C High

Genista monspessulana (French broom) C High

Hypericum perforatum (Klamath weed) C Moderate
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Weed Species CDFA* California Invasive Plant Council**

Lepidium latifolium (tall whitetop) B High

Linaria genistifolia ssp. dalmatica (dalmatian toadflax) A Moderate

Robinia pseudoacacia (black locust) N/A Limited

Rubus armeniacus (=R. discolor) (Himalayan blackberry) N/A High

Spartium junceum (Spanish broom) N/A High

Verbascum thapsus (wooly mullein) N/A Limited

*California Department of Food and Agriculture Ratings (CDFA) 2007

A-Eradication, containment, rejection, or other holding action

B-Eradication, containment, control or other holding action at the direction of the County Agricultural Commissioner

C-State endorsed holding action and eradication only when found in a nursery

**California Invasive Plant Council Ratings (CalIPC)

High – Severe ecological impacts, reproductive biology and other attributes are conducive to moderate to high rates of dispersal 

and establishment. Species usually widely distributed ecologically among and within ecosystems.

Moderate – Substantial and apparent, but not severe, ecological impacts; attributes are conducive to moderate to high rates of 

dispersal, though establishment is generally dependent on ecological disturbance. Ecological amplitude and distribution may range 

from limited to widespread.

Limited – Invasive, but either their ecological impacts are minor on a statewide level or information on them is insufficient to justify a 

higher rating, although they may cause significant problems in specific regions or habitats. Reproductive biology and other attributes 

result in low to moderate rates of invasion. Ecological amplitude and distribution are generally limited, but these species may be 

locally persistent and problematic.

Sensitive plants and fungi and/or watchlist species occurrences located in and/or near motorized 

vehicle routes have a high risk of negative impacts from weed introduction and spread. Surveys of over 

95 miles of unauthorized motorized roads/trails/areas have been completed. Refer to Table 3.06-13 for a 

list of the proposed additions to the NFTS that have weed occurrences located within 100 feet or less of 

them.

Weeds are known to directly/indirectly impact sensitive plant occurrences. For example, an 

occurrence of the sensitive species Clarkia biloba ssp. Brandegeae is currently being impacted by the 

invasion of yellow star thistle along the Mosquito Ridge road located outside of Foresthill. Table 3.06-4 

displays the unauthorized routes and closed NFTS roads still receiving some motorized use where 

sensitive/watchlist plants and/or plant communities have been discovered. These occurrences are at 

increased risk of loss of individuals and habitat due to weed introduction and spread over the short and 

long term. The sensitive/watchlist species occurrences that have known weed occurrences located within 

100 feet are at even greater risk of negative impacts from weed infestation.

Table 3.06-4. Unauthorized Routes and Closed NFTS roads still receiving some motorized use with Sensitive 

and Watchlist Plants/Plant Communities*

Route ID Name of Sensitive/ Watchlist Plant, watchlist 

plant community

Known weed occurrence within 

100 feet

TKN-J2 Vernal pool None

TKN-J5 Erigeron miser, Bruchia bolanderi, seep/spring None

TKN-J13 Aspen, seep/spring Cheatgrass

TKN-M2 Ivesia sericoleuca, aspen, seep/spring Cheatgrass

TKS-11 Aspen None

YRN-001 Epilobium howellii None

YRN-7 Erigeron petrophilus var. sierrensis None
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Route ID Name of Sensitive/ Watchlist Plant, watchlist 

plant community

Known weed occurrence within 

100 feet

YRS-F1 near Fordyce 

Creek crossing 

Erigeron miser None

YRS-SF4 Seep/spring None

YRS-SF5 Seep/spring None

SV-005 Aspen, seep/spring None

SV-P14 Aspen Cheatgrass, musk thistle

*Sensitive plant occurrence is within 100 feet of the road/trail/area.

Vegetative recovery in weed infested areas: When the motorized vehicle use on a route is removed, 

the recovery of native vegetation can be affected by the presence of weeds within and adjacent to that 

route. Vegetative recovery in areas infested with weeds may not occur if the weeds are not eliminated and 

desired native vegetation is encouraged (Bard et al 2008). The amount of time needed for the route to 

revegetate with native species is dependent on many factors including the type of weed at the site. Refer 

to the weed risk assessment for this project located in the project file for more information about 

ecological characteristics of weeds known to occur on the TNF. Continued motorized vehicle use within 

aspen plant communities could spread weeds so that aspen regeneration is reduced increasing the risk of 

loss of these plant communities.

Native Plant Habitat Fragmentation

Many acres of TNF system lands are considered fragmented with other ownership lands embedded within 

and adjacent to them. The presence of these inholdings affects the current condition and future outlook of 

TNF system lands. For example, most of the lower elevation, westside oak woodland plant communities 

are in private ownership and are experiencing rapid development as home sites. The existence of 

developed land adjacent to NFS land often increases the amount of human activity on the NFS land and 

increases the risk of unauthorized routes, and weed introduction/spread onto NFS lands. Plant 

communities located on inholding lands can be managed much differently than NFS lands and can reduce 

the desired connectivity of plant communities.

Connectivity of native plant communities is often described in terms of large geographic areas of 

particular vegetation types (such as mixed conifer) that are not fragmented by roads, development or other 

disturbances. The largest geographic areas other than wilderness on TNF system lands that have limited 

road/development/disturbance are the Inventoried Roadless Areas (IRAs). However, it is recognized that 

wilderness areas, Special Interest Areas (SIAs), and Research Natural Areas (RNAs) also provide some 

native plant community connectivity but generally on a smaller scale. Refer to Section 3.09 for a more 

information about wilderness, SIAs, and RNAs.

Wilderness: The Granite Chief wilderness is about 24,864 acres in size and contains high elevation 

forests and meadows. Motorized vehicle use within Granite Chief is prohibited. None of the alternatives 

change management of this wilderness area. Therefore, native plant connectivity within Granite Chief 

Wilderness area will not be impacted by motorized vehicle activity regardless of the alternative selected.
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SIAs: The SIAs located on the TNF include: Placer County Big Tree Grove Botanical area, Devil’s 

Postpile Geologic area, Glacier Meadow Geologic area, Grouse Falls Scenic area, Meadow Lake Cultural 

area, Sagehen Headwaters, and Mason Fen area. No changes in management of these SIAs will occur 

under implementation of any of the alternatives. Motorized vehicle use within these SIAs is either 

excluded or discouraged. Therefore, native plant connectivity within these SIAs will not be impacted by 

motorized vehicle activity. Placer County Big Tree Grove, Sagehen Headwaters, and Mason Fen SIAs 

were established for their native plant characteristics. However, these botanical SIAs are relatively small 

in area.

RNAs: Lyon Peak/Needle Lake, Sugar Pine Point and Babbitt Peak are the RNAs located on the TNF. 

Motor vehicles are excluded from all of these RNAs including the No Action Alternative. Therefore, 

native plant connectivity within these RNAs will not be impacted by motorized vehicle activity. None of 

the alternatives propose changes to the existing management of these RNAs. These RNAs provide some 

native plant community connectivity but at a much smaller scale than IRAs and Granite Chief Wilderness.

IRAs: The TNF has eleven IRAs. The character and amount of roads, private land, and motorized 

trails varies greatly by IRA. Refer to Section 3.09 for the names and acres of IRAs on the TNF. Some of 

the IRAs contain motorized vehicle roads/trails/areas (routes). The existing condition of routes within 

RNAs varies. Some started as mining trails and were not made for motorized vehicle use. Over time, 

these foot/animal trails became wagon trails and then vehicle trails and eventually some of them have 

become system motorized vehicle routes. Current use of the unauthorized motorized vehicle routes and 

closed NFTS roads in TNF IRAs is considered light to moderate primarily due to such factors as level of 

difficulty and remote location. 

Large geographic areas such as IRAs that are relatively undisturbed by humans are important for 

native plants both individually and cumulatively to help maintain species viability and biodiversity 

(USDA FS 2000, Loomis et al. 2000). Nationally, they play an important role in providing habitat for 

threatened, endangered, proposed and sensitive (TEPS) plant species (ibid). TNF IRAs are not known to 

contain TEP plants, but do have occurrences of sensitive and watchlist plants. Nationally, IRAs provide 

important habitat for more than 1,400 sensitive and almost 100 threatened, endangered and/or proposed 

(TEP) plant species (ibid) and are considered important biological strongholds for native plant species and 

communities (ibid). TNF IRAs have not been surveyed. Therefore, the number of TEPS and watchlist 

plants/plant communities that occur within them is unknown.

Native vegetation within large geographic areas such as IRAs is less likely to be exposed to 

disruption by human activities such as collection, trampling, and other surface disturbance. This lower 

level of human disruption may make IRAs important references for understanding the natural 

composition and dynamics of native plant communities (USDA FS 2000). Roadless areas are less likely 

to experience problems with weed species and are more likely to be able to maintain intact native plant 

communities (ibid).

Conservation and management of the biodiversity of the Sierra Nevada is a priority and human land 

uses are considered the most pervasive threats to native plants in the Sierra Nevada (Murphy et al. 2004). 

Large geographic blocks of land contain naturally functioning ecosystems that provide many valuable 
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services including watershed protection, carbon storage, nutrient cycling, pest control, pollination, and 

fish and wildlife habitat. Preserving naturally functioning ecosystems (natural environments) provides 

many benefits to society (Krutilla and Fisher 1975 in Loomis et al. 2000).

The effects of motorized vehicle use on native plant connectivity have not been fully studied. 

However, motorized vehicle use is known to change the plant composition within the areas where the use 

occurs. In one study done in Idaho, native shrubs/bunch grasses/microbiotic crusts were less prevalent and 

disturbance loving plants were more prevalent closer to motorized trails. Motorized vehicles directly 

damaged the native plants and microbiotic crusts and disturbed the surrounding habitat enough to 

facilitate invasion by weeds. Many weeds (such as the cheatgrass in this study) are known to help spread 

fire. When wildfire occurs in areas infested with cheatgrass, the native vegetation is frequently lost and 

the cheatgrass spreads - eventually becoming a monoculture. Motorized vehicle use is also known to 

increase the amount of bare ground and decrease the cover of microbiotic crust, negatively affecting 

nutrient cycling and increasing erosion. Dust created by the motorized vehicle use has been shown to 

decrease native plant cover by reducing rates of photosynthesis, leaf conductance, transpiration, and water 

use efficiency. Dust can also increase temperatures of leaves and stems and decrease leaf surface areas 

(Munger et al 2003). Changes in plant composition and plant community functions (such as the rate and 

spread of wildfire) reduce native plant connectivity and fragment native plant communities. In general, 

the degree of fragmentation/amount of connectivity loss depends on the intensity and extent of motorized 

vehicle use. However, even a single motorized vehicle pass can kill and/or injure many types of native 

plants and introduce weed seed. Native plants with shallow root systems are especially vulnerable 

(Wilshire 1983, Lacey et al. 1997). Native vegetation species vary in their ability to resist being damaged 

and in their ability to recover from the damage (Cole 1995). However, all native vegetation appears to 

have a threshold beyond which the species can no longer recover from motorized vehicle damage and/or 

other disturbances.

Loss of native vegetation increases the risk of soil loss due to wind and water erosion. Soil erosion 

accelerates decomposition of organic matter, weakens soil aggregate stability and results in the formation 

of inorganic surface crusts. Inorganic surface crusts increase water runoff, inhibit seed germination and 

emergence of seedlings, and reduce water penetration. Natural soil stabilizers such as lichen, fungal and 

algal crusts are highly vulnerable to damage from motorized vehicle use (Cole 1995).

Motorized vehicle use is known to influence the native vegetation and therefore the biodiversity of 

the area where the use is occurring. As mentioned above, plant biodiversity is at an increased risk of 

adverse cumulative effects from increased population growth and associated land uses, land conversions, 

and nonnative species invasions both nationally and regionally. National Forests with many inholdings 

such as the TNF have increased risks to biodiversity from nonnative species invasions. Limiting 

motorized vehicle disturbance within these large geographic areas would provide increased assurances 

that biological diversity in those areas would be conserved. This biological diversity conservation would 

be achieved by maintaining the native plant communities where weed species are currently rare, 

uncommon, or absent because motorized vehicles are known to introduce weeds into new areas. Once 

weeds are established, they provide a source of weed seed to spread to new areas. The value of large 
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geographic areas such as IRAs in conserving biodiversity is likely to increase as native plant communities 

are lost and/or degraded (USFS 2000). Native plant community loss and degradation, and impacts to 

native plant communities from the invasion and/or encroachment of weeds are increasing nationally and 

regionally. Increased weed infestation is recognized as a primary threat to biodiversity.

Environmental Consequences

All of the action alternatives reduce the effects of motorized vehicle travel on native plants/plant 

communities by prohibiting cross country travel. In addition, all action alternatives prohibit motorized 

vehicle use on some unauthorized roads/trails/areas (routes) and closed NFTS roads still receiving some 

motorized use. A number of things could happen to routes when motorized vehicle use is prohibited (refer 

to the affected environment discussion). Some of the routes may be actively closed by the TNF after 

conducting NEPA. This would benefit sensitive/ watchlist species because they would be avoided during 

route closure and would have reduced risk after the route was closed. Some of the routes may be proposed 

for addition to the NFTS at a later date, again after conducting NEPA. In this scenario, sensitive/watchlist 

species would be avoided during reconstruction/maintenance, but would be at increased risk from dust 

and weed invasion. Some of the routes may be left to revegetate and will not be visible on the ground

after about 5 years. Under this scenario some sensitive/watchlist species would benefit. Others that need 

openings would not benefit. Other routes may continue to be used for non-motorized recreation. Nonmotorized recreational activities can also negatively impact sensitive/watchlist species through direct 

impacts to the plants and competition from invading weeds, but foot and horse travel are considered less 

impacting than motorized travel.

Assumptions 

The analysis of effects to botanical resources/native vegetation is based on the assumptions listed below:

• Motorized vehicle use within and adjacent to rare species occurrences have the ability to 

negatively impact the long-term viability of specific plant and fungi species.

• Impacts to sensitive/watchlist species and/or native plant communities are assumed to be limited 

to the route footprint and the area immediately adjacent (within 100 feet) to it. 

• Sensitive/watchlist species and/or native plant communities located within 100 feet of a proposed 

motorized addition to the NFTS may be indirectly impacted by motorized vehicle use - regardless 

of the alternative selected. 

• Sensitive/watchlist species and/or native plant communities located within one vehicle length of a 

proposed motorized addition to the NFTS may be directly impacted by motorized vehicle use 

regardless of the alternative selected. 

• Sensitive/watchlist species and/or native plant communities occur within the identified potential 

habitat that has not been surveyed. Occurrence is assumed until surveys are completed so that 

analysis of possible impacts can be done.

• Without specific prevention and/or control measures, non-native plants (weeds) will continue to 

spread along and within surfaced and unsurfaced motorized vehicle roads/trails/areas.
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• It is the agency position that just putting a route on a map will not increase the use of that route. 

However, it is assumed that motor vehicle use of unsurfaced roads/trails/areas will increase 

sediment production and erosion and that increased use will cause increased sediment production 

and erosion.

• The projects identified in Appendix H (Reasonably Foreseeable Projects and Cumulative Effects) 

will be analyzed and implemented on TNF system lands within the next 5 to 10 years. 

• All vehicles are assumed “equal.” All vehicles were assumed equal in this analysis as many of the 

motorized routes being analyzed would be open to all types of motorized vehicles, making it 

impossible to determine which type of vehicle would be using which route at any given time.

Hence the impacts to sensitive/watchlist species/native plant communities from a motorcycle are 

assumed equal to those impacts from a 4-wheeled vehicle. 

• Volunteers can effectively maintain adopted trails over the long term.

Data Sources

Data from the following sources was used in this analysis:

• Road/trail/area specific surveys for this project.

• TNF GIS layers for weeds, special aquatic features, streams, sensitive plants, watchlist plants and 

plant communities, RNAs, SIAs, soils, and vegetation.

• Botanical surveys conducted for a variety of projects including: livestock grazing allotments, fuel 

reduction, mining, etc. 

• Scientific literature on: specific rare plants/fungi and/or their habitats, native plant communities, 

non-native plants (weeds), climate change and its effects on weed spread/native plant 

communities, and native plant habitat fragmentation.

• Other data sources including: CNDDB, CNPS On-line Inventory, PLANTS database, Nature 

Serve, and Jepson Interchange.

Indicator Measures

The following general indicator measures were used to compare alternatives in regard to known 

occurrences of sensitive/watchlist species and/or plant communities and to potential habitat without 

current surveys. These indicator measures were selected based on literature review and professional

judgment.

• Number of perennial and intermittent water crossings.

• Proposed addition to the NFTS within 100 feet of unsurveyed potential habitat.

• Sensitive/watchlist species and/or watchlist plant communities within one vehicle length of

proposed additions (direct effects). Since vehicles are allowed to pull off routes to a distance of 

one vehicle length, there is a possibility of direct impacts to sensitive/watchlist species and/or 

other vegetation within that distance from the proposed addition.

• Sensitive/watchlist species and/or watchlist plant communities within 100 feet of proposed 

addition (indirect effects). One hundred feet was chosen to define the distance for indirect 

impacts to sensitive/watchlist species based on successful reduction of direct and indirect impacts 
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to sensitive/watchlist species located more than 100 feet away from other types of grounddisturbing management activities that have been implemented in the past. Soil and water TNF 

staff has used a 100-foot buffer for perennial water to reduce/eliminate impacts from a variety of 

projects (to protect water quality from negative impacts from other types of management 

activities). Soil and water staff report that “A recent review of scientific literature revealed that a 

100-foot riparian buffer is adequate to mitigate against significantly impacting riparian and 

aquatic resources” (Spackman and Hughes 1995 and Steinblums, I. J., H. A. Froehlich, and J. K. 

Lyons, 1984).

• Weed infestations within 100 feet of the proposed addition. One hundred feet was chosen to 

define the distance that weed seed could travel from an established weed occurrence via vehicle 

tires. In reality, the distance would probably be further than 100 feet and/or less than 100 feet 

dependent on many factors.

• Miles of proposed additions within inventoried roadless areas. This indicator was chosen to 

assess potential effects on plant community fragmentation in large blocks of land.

Elements of the proposal

In addition to the indicator measures, the alternatives are compared by plant community with a focus on 

the major parts of the proposal:

• Prohibition of cross country travel [including unauthorized routes and closed NFTS roads still 

receiving some motorized use].

• Additions to the NFTS (including roads and motorized trails)

• Establishment of motorized “Open Areas”

• Changes to the NFTS (including change in the class of vehicles resulting from approval of mixed 

use, change in the class of vehicles resulting from changes in maintenance levels, changes in 

seasonal restrictions, over the snow travel, and re-opening Maintenance Level 1 (ML 1) roads 

making them ML-2 roads). 

• Amendments to the Forest Plan

• Cumulative effects including all of the above and the reasonably foreseeable. The spatial 

boundary of the cumulative effects analysis area is the TNF.

There are some elements of the project proposal that do not differ significantly in their impacts to 

sensitive/watchlist species and/or plant communities regardless of the alternative selected, or the type of 

plant community. These elements of the proposal include: Establishment of motorized “Open Areas,”

changes to the NFTS, and amendments to the Forest Plan. The consequences of implementing these 

elements of the proposal are presented below:

Establishment of motorized “Open Areas”

Indicator(s) used to measure effects:

• Acres of “Open Area”
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No Action: Alternative 1 does not propose acres of “Open Areas” for reservoir access or the 

Greenhorn area, but it does not prohibit use of these areas either. Alternative 1 has the greatest risk of 

negative effects to native vegetation, when compared to the action alternatives. However, since the 

reservoir shoreline access areas and the Greenhorn area have been surveyed and no sensitive/watchlist 

species were found, direct impacts to sensitive/watchlist species are not expected. Implementation of 

Alternative 1 could spread weeds and could therefore indirectly impact sensitive/watchlist species and/or 

native plant communities in other areas. Bare soil such as what appears around reservoirs when the water 

level recedes, provides ideal areas for weeds to become established. Weeds can grow in these areas for 

several growing seasons - until water levels rise again and are high enough (and stay high enough) to 

drown or rot any seeds in the soil. The amount of bare soil around reservoirs and timing/duration of water 

levels is difficult to predict. However, any vehicle that drives over a weed infested area has the ability to 

spread weed seed and/or plant parts from the open area to other areas. The spreading of weeds from one 

place to another is an indirect impact to the native plants located where the weeds are spread. The area 

around Boca Reservoir is known to be heavily infested with the “A” rated weed – musk thistle and has 

areas adjacent to the Reservoir that have been infested with spotted knapweed. The bare soil in the low 

water line around Boca Reservoir provides suitable establishment sites for musk thistle and spotted 

knapweed. Use of this bare soil area by motor vehicles could spread these highly invasive weeds to new 

areas.

Action alternatives: In general terms, the action alternatives prohibit cross country travel, however, 

Alternatives 2 and 6 allow cross country travel in “Open Areas.” Alternative 2 proposes the addition of 

about 2,649 acres of “Open Areas” as open shoreline access on dry soils around Boca, Prosser and 

Stampede Reservoirs (2,589 acres) and the Greenhorn open area (60 acres). Alternative 6 proposes 

specific designated access routes through the open shoreline areas of Boca, Prosser and Stampede (244 

acres), but does not propose the addition of the Greenhorn open area. Alternatives 3, 4, 5, and 7 do not 

propose shoreline access or the Greenhorn open area.

None of the action alternatives would directly impact sensitive/watchlist species through addition of 

“Open Areas” since the “Open Areas” have been surveyed and no sensitive/watchlist species were found.

However, Alternatives 2 and 6 could indirectly impact sensitive/watchlist species and native plant 

communities. Alternative 2 has the greatest risk of the action alternatives of indirectly impacting 

sensitive/watchlist species and/or native plant communities through the spread of weeds since it proposes 

the addition of the most acres of open area. Alternative 6 has less risk of weed spread than Alternative 2

because it proposes the addition of specific “lanes” for low water access. Providing access along specific 

routes reduces the area that would be used by motorized vehicles reducing the area in need of future weed 

survey. Weeds are much easier to treat if they are detected when they are first becoming established.

Changes to the NFTS

No Action: Alternative 1 does not change the class of vehicles that can use a particular route and does not 

implement seasonal restrictions. Implementation of Alternative 1 would not impact sensitive/watchlist 

species and/or native plant communities any differently than they are currently being impacted. Impacts 
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would vary dependent on many variables including the types of plant communities the route passes 

through (different plant communities provide habitat for different sensitive/watchlist species); amount of 

motorized use of the route; etc.

Action alternatives: It is difficult to determine how implementation of a particular action alternative

could impact sensitive/watchlist species and/or native plant communities when there is a change in the 

class of vehicles that use a system route or a change in the time when a road can be used (implementation 

of seasonal restrictions). Refer to the following discussion:

1. Change in type of vehicle: Changing the type of vehicle that can use a specific route could 

negatively impact sensitive/watchlist species and/or native plant communities that occur along that route.

It is recognized that the width of the route could vary if the proposed change made the route narrower.

However, many of the motorized routes being analyzed would be open to all types of motorized vehicles 

and do not reduce the width of routes. It is impossible to predict what type of motorized vehicle will be 

using which route at any given time since motorcycles and 4-wheel-drive vehicles can all use many of the 

routes. Hence for analysis purposes, the impacts to sensitive/watchlist species and/or native plant 

communities from use of a motorcycle are assumed equal to those impacts from a 4-wheeled vehicle and 

do not differ significantly by action alternative. 

It is likely that direct impacts to sensitive/watchlist species and/or plant communities occurred when 

the road was developed. Indirect impacts may still be occurring if the sensitive/watchlist species and/or 

plant communities have survived within 100 feet of the road. These indirect/cumulative impacts would 

continue regardless of the type of vehicle using the road. In addition, there are no studies that indicate one 

type of vehicle spreads weed seed and/or weed plant parts more than another. Therefore, changing the 

class of vehicle does not make the road more or less susceptible to weed introduction and spread and does 

not reduce the risk of sensitive/watchlist species and/or plant communities being lost or degraded.

2. Seasonal restrictions: The impact to native plant communities and the sensitive/watchlist species 

dependent on them from implementation of seasonal restrictions varies by plant community and species. 

However, the significance of beneficial or negative impacts from the seasonal restriction is difficult to 

quantify for a number of reasons. Removing motorized vehicle use from routes during the wet season 

does reduce the potential amount of erosion from that route that could occur especially if the route 

becomes rutted. However, this amount of potential erosion can not be quantified. Determining where the 

rutting and erosion would take place and if that erosion would impact sensitive/watchlist species and/or 

plant communities is difficult. It is reasonable to assume that those sensitive/watchlist species and/or 

native plant communities located within one vehicle length of a proposed addition to the NFTS would not 

benefit from soil erosion regardless of the season of use.

Some sensitive/watchlist species would have limited impacts from season of use restrictions. Those 

sensitive/watchlist species that are aquatic/riparian plant community dependent are always subject to 

erosion and/or soil rutting because those native plants grow in soils that are wet/moist year-around. 

Serpentine (ultramafic soils) plant communities are considered highly erosive year-around. The known 

occurrences of rare plants located within one vehicle length of a system motorized vehicle route that are 

dependent on older forest plant communities (such as Cypripedium fasciculatum occurrences) are all 
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located within road cut-banks. Due to their location in reference to the system roads, they would not be at 

risk from increased erosion unless the entire road washed out. Erosion at levels that would wash out entire 

roads is not expected regardless of the season of use. It is recognized that implementing seasonal 

restrictions to reduce the amount of motorized use on wet soils could benefit sensitive/watchlist species 

and/or native plant communities. However, even one vehicle pass can kill a plant or group of plants

regardless of the time of year the tire passes over the vegetation. Therefore, it is very difficult to quantify 

differences between action alternatives based on seasonal restrictions. In addition, the seasonal 

restrictions do not necessarily prohibit motorized vehicle use during the growing season. For example, the 

season of use for TKN-M2 that has a known occurrence of Ivesia sericoleuca is May 1 to December 1.

Ivesia sericoleuca grows on the eastside of the Forest at elevations where snowmelt from meadows would 

occur near May 1. Therefore the seasonal restriction does not benefit the Ivesia sericoleuca occurrence 

other than possibly reducing the amount of soil compaction/rutting/water channeling that could occur if

the route were open earlier than May 1.

The action alternatives that do not have seasonal restrictions could negatively impact 

sensitive/watchlist species and/or plant communities if motorized use occurs on a route when the soils are 

wet. However, many of the proposed additions occur at elevations that would prohibit use of the route 

before May 1st anyway due to snow accumulation. For example, Epilobium howellii occurs at the end of 

YRN-001. YRN-001 is proposed for addition to the NFTS in Alternatives 2, 5 and 6. Alternative 2 would 

have YRN-001 open all year; Alternative 5 would have the season of use from May 1 to December 31; 

and Alternative 6 would have the season of use from April 1 to December 31. From personal experience, 

it is rare to be able to access the area where YRN-001 is located before mid June and most years the area 

is snowed in by December. In addition, if there is a known sensitive/watchlist species and/or plant 

community within 100 feet of a route, mitigations have been developed to reduce or eliminate impacts 

and seasonal restrictions would not change the mitigations. Therefore, there really isn’t a difference in 

impacts to sensitive/watchlist species and/or plant communities for any alternative in regard to seasonal 

restrictions. When compared to Alternative 1, there is no difference in impacts.

Amendments to the Forest Plan

No Action: Alternative 1 does not propose Forest Plan amendments. Therefore implementation of this 

portion of Alternative 1 would not impact sensitive/watchlist species and/or native plant communities.

Action alternatives: Alternatives 2, 5 and 6 propose amendments to the Forest Plan (change the 

seasonal restriction for deer winter range in Management Area 84).The other action alternatives do not 

propose this Forest Plan amendment. Amending the Forest plan in regard to seasonal restriction for deer 

winter range in Management Area 84 would not impact sensitive/watchlist species and/or native plant 

communities.

Elements of the Proposal that Vary by Alternative

Implementation of some elements of the proposal shows variation of effects by alternative and by plant 

community. These elements of the proposal include: 1) prohibition of cross country travel, 2) additions to 
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the NFTS and reopening of ML 1 roads, and 3) cumulative impacts including reasonably foreseeable.

These three elements of the proposal are analyzed by plant community.

Aquatic/Riparian Plant Communities

1. Prohibition of cross country travel

Indicator(s) used to measure effects:

• Acres where cross country travel is prohibited (thereby reducing the mileage of routes available 

for motorized use). Mileage reduction includes unauthorized routes and closed NFTS roads still 

receiving some motorized use located within 100 feet of riparian vegetation.

• Number of perennial and intermittent water crossings on routes where public motorized vehicle 

use is prohibited

No Action: Alternative 1 does not prohibit cross country travel. Therefore, about 134,222 acres of 

riparian vegetation could be impacted by cross country travel. Under implementation of Alternative 1 

impacts to known occurrences of sensitive/watchlist species dependent on aquatic/riparian plant 

communities would likely increase over time as motorized vehicle use increases. As yet undiscovered 

sensitive/watchlist species would be at risk as new routes were created. It is likely that cross country use 

would kill and/or injure at least some sensitive/watchlist species and it is reasonable to expect that some 

occurrences would be lost. Those sensitive species considered in downward trend would be most at risk 

for loss of viability. TNF sensitive plants in a downward trend that are dependent on aquatic/riparian plant 

communities include: Ivesia aperta var. canina and Ivesia webberi. Since Ivesia aperta var. canina and 

Ivesia webberi are experiencing a downward trend across their range of occurrence, impacts to them 

could be significant if they occur on TNF system lands.

Direct/indirect impacts could be significant at least at the local, site specific level. Possible direct 

impacts include killing and/or injuring sensitive/watchlist species and/or native vegetation by running 

over them. Severe and persistent disturbance to sensitive/watchlist species occurrences and/or 

aquatic/riparian plant communities could convert them to a different type of plant community. The 

significance of these impacts is dependent on many factors including the amount of disturbance, the 

sensitive/watchlist species being impacted, and in some cases, the season when the disturbance takes 

place (for example, running over a sensitive/watchlist species while it is in bloom could negatively impact 

reproduction - at a minimum. Running over the same plant while it is dormant and underground would 

not have the same impacts - especially if the soil health is not reduced). The significance of impacts is 

also dependent on the number of sensitive/watchlist species that occur in a specific location and how 

many of them are injured and/or killed. In addition, the significance of impacts is dependent on the 

amount and condition of the type of habitat needed by a particular sensitive/watchlist species across its 

range of distribution.

When a sensitive/watchlist species is dependent on plant communities that are limited (for example 

Meesia uliginosa is usually found in fens and fens are plant communities of limited distribution), impacts 

could be significant. The type of motorized vehicle is not a factor since all vehicles are known to have 

adverse impacts to natural resources (Foltz and Meadows 2007). It is impossible to know when or where 
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cross country motorized vehicle use would occur, but since it would not be restricted in Alternative 1, the 

risk of significant direct/indirect impacts is higher than in the action alternatives.

If cross country motorized vehicle use reduced the soil health within a sensitive/watchlist occurrence 

through compaction, increased erosion, changed water flows, and/or introduced weeds, the 

sensitive/watchlist occurrence would have reduced health, and/or could be converted to a different plant 

community. Conversion to another plant community would be considered significant especially at the site 

specific level.

In most cases, recommendations for sensitive/watchlist species – especially aquatic/riparian plant 

communities - are for protection from impacts. Most TNF sensitive/watchlist species are considered 

aquatic/riparian dependent and are limited in distribution. When an occurrence has reductions in the 

health of the soil and/or changes to the amount or health of water/air/vegetation components of the 

habitat, those sensitive/watchlist species habitats may not be able to maintain and/or perform their natural 

prescribed functions (Foltz and Meadows 2007). Refer to Section 3.02 for more information regarding 

soil and water. Allowing unrestricted motorized vehicle use across the Forest greatly increases the risk of 

negative direct/indirect impacts to sensitive/watchlist species.

Unauthorized routes and continued motorized use of closed NFTS roads are considered an expression 

of cross country travel. TNF unauthorized routes and closed NFTS roads still receiving some motorized 

use have about 908 perennial and intermittent water crossings and 146 miles located within 100 feet of 

riparian vegetation. Alternative 1 has the greatest number of perennial and intermittent water crossings 

and greatest number of miles of motorized vehicle use located within 100 feet of riparian vegetation of all 

alternatives. Therefore, Alternative 1 has the greatest risk of negative impacts to aquatic/riparian plant 

communities and those species dependent on them.

Action alternatives: In general terms, the action alternatives prohibit cross country travel. Therefore, 

no direct, indirect, or cumulative impacts to sensitive/watchlist species and/or aquatic/riparian watchlist 

plant communities (from cross country travel) are expected.

2. Additions to the NFTS and Reopening ML 1 Roads

Indicator(s) used to measure effects:

• Miles of proposed additions to the NFTS that are located within 100 feet of riparian vegetation.

• Number of proposed additions with perennial and intermittent water crossings 

• Sensitive/watchlist species and/or watchlist plant communities located within 100 feet of 

proposed additions to the NFTS

• Weed sites located within 100 feet of proposed additions to the NFTS 

No Action: Alternative 1 does not propose the addition of routes to the NFTS. However, 

implementation of Alternative 1 could impact sensitive/watchlist species and/or aquatic/riparian plant 

communities directly/indirectly by continuing use of about 908 perennial and intermittent water crossings

and 146 miles of route located within 100 feet of riparian vegetation. Refer to the discussion under effects 

of cross country use under the No Action Alternative above. Direct/indirect impacts could be significant at 

least at the site specific level.
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Surveys located several aquatic/riparian dependent sensitive/watchlist species and/or plant 

communities along or within 100 feet of several routes: Bruchia bolanderi along TKN-J5; Epilobium

howellii at the end of YRN-001; Ivesia sericoleuca along TKN-M2 (cheatgrass infestations were found 

within 100 feet of the TKN-M2 Ivesia sericoleuca occurrence); aspen along TKN-M2, TKS-11, SV-005, 

and SV-P14; a vernal pool at the end of TKN-J2; and springs/seeps along SV-005, TKN-J5, TKN-M2, 

YRS-SF4 and YRS-SF5.

Implementation of Alternative 1 would continue to impact these sensitive/watchlist species and/or 

watchlist aquatic/riparian plant communities directly, indirectly, and cumulatively. The significance of 

these impacts is dependent on many factors including the amount of disturbance. Under implementation 

of Alternative 1 the risk of significant (occurrence scale) soil compaction, increased erosion, changed 

water flows, and/or weed introduction is high.

Action alternatives: Tables 3.06-5, 3.06-6, and 3.06-7 display the number of perennial and 

intermittent water crossings, the number of miles of proposed additions located within 100 feet of riparian 

vegetation, and identify the proposed additions to the NFTS where surveys identified sensitive/watchlist 

species and/or watchlist plant communities. The following discussion is divided into impacts to known 

occurrences and impacts to potential habitat that lacks current surveys.

A. Impacts to known occurrences:

Vernal pool watchlist plant community: Implementation of Alternatives 2, 4, 5, 6, and 7 would impact 

the vernal pool at the end of TKN-J2. TKN-J2 is proposed for addition to the NFTS under all action 

alternatives except Alternative 3. Mitigation measures specified in Appendix A (Site Specific Road, Trail 

and Open Area Information) require barriers to placed around the vernal pool/seasonal wetland so that 

damage from motorized use is reduced/eliminated. Continued motorized vehicle use within this vernal 

pool would eventually cause a loss of the native plants within it - if mitigations were not implemented,

and the vernal pool plant community would be lost. Barriers would be placed at the end of TKN-J2 to 

eliminate direct impacts to the vernal pool from motorized vehicle travel. The vernal pool would still be at 

risk from indirect impacts under Alternatives 2, 4, 5, 6, and 7 – especially increased risk of weed 

introduction and spread. Implementation of Alternative 3 provides benefits to the vernal pool by reducing 

the risk of weed introduction/spread and the amount of dust produced by motor vehicle use of TKN-J2.

Seep/spring watchlist plant communities: As mentioned above, seep/spring plant communities 

were found along routes SV-005, TKN-J5, TKN-J13, TKN-M2, YRS-066, YRS-SF4, and YRS-SF5. SV005 and YRS-066 are proposed in Alternatives 2, 5 and 6. No mitigations are proposed for SV-005 since 

motorized vehicle use is not currently impacting the seep/spring plant community along the route. No 

mitigations are proposed for YRS-066 since motorized vehicle use is not currently impacting the 

developed spring located about 50 feet away from it. TKN-J5 is proposed in Alternatives 2, 5, 6, and 7.

The water from the seep would be directed to the meadow instead of down the route. TKN-M2 is 

proposed in Alternatives 2, 5 and 6. Barriers would be placed along the route where it passes through the 

seep/spring plant community. YRS-SF4 is proposed in Alternatives 2, 5, and 6. Water from the 

seep/spring plant communities would be directed so it does not flow down the road. TKN-J13 and YRS-
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SF5 is proposed in Alternatives 2, 4, 5, 6, and 7. The damaged seep/spring plant community located off of 

route YRS-SF5 would be restored prior to this route being available for motorized use. The wet areas 

along TKN-J13 would have soil and water mitigations implemented in Alternatives 2, 4, 5 and 7. In 

Alternative 6, TKN-J13 was shortened from 1.6 miles to .1 miles in length to avoid the seep/spring plant 

communities altogether. When compared to Alternative 1, implementation of these mitigations would

reduce, but not eliminate, impacts to these seep/spring plant communities. Remaining impacts to the

seep/spring plant communities contribute to cumulative impacts to aquatic/riparian plant communities.

Alternatives 3 and 4 do not propose the addition of SV-005, TKN-J5, TKN-M2, YRS-066 or YRS-SF4 to 

the NFTS and Alternative 3 does not propose the addition of TKN-J13 or YRS-SF5 to the NFTS.

Therefore, seep/spring plant communities along those proposed additions benefit from the prohibition of 

public motorized vehicle use of those routes in Alternatives 3 and 4.

Aspen watchlist plant communities: Aspen watchlist aquatic/riparian plant communities were found 

along SV-005, SV-P14, TKN-J11, TKN-M2, and TKS-11. Barriers would be placed on either side of the 

proposed additions where they pass through the aspen plant communities along routes SV-P14, TKS-11

and TKN-M2. Impacts to aspen communities, caused from implementing the action alternatives, would be 

less than Alternative 1. No mitigations were proposed for aspen plant communities located along routes 

SV-005 and TKN-J11 since negative impacts to the aspen from motorized vehicle use were not detected

during field surveys.

Sensitive plants: Table 3.06-7 shows that Bruchia bolanderi along TKN-J5 and Ivesia sericoleuca

along TKN-M2 are at higher risk in Alternatives 2, 5, 6, and 7 because both of those routes are proposed 

additions in those alternatives. The stream crossing at Castle Creek (TKN-J5) would be routinely checked 

to determine whether users are widening the crossing. Widening the crossing would put motor vehicles 

that much closer to Bruchia bolanderi. Barriers and signs would be placed adjacent to Castle Creek to 

keep users from reducing vegetative cover adjacent to the stream, increasing sediment. Barriers would

also be placed so that turn-arounds, camping and parking do not occur with 100 feet of Castle Creek.

These mitigations would reduce but not eliminate impacts to the Bruchia bolanderi occurrence located 

along Castle Creek, when compared to Alternative 1.

Barriers would also be placed on either side of TKN-M2 where it goes through the Ivesia sericoleuca

and to block access to the route spur that passes through the occurrence. Any cheatgrass that spreads to 

the Ivesia sericoleuca occurrence would be manually treated. Barriers would also be placed on either side 

of TKN-M2 where it passes through the aspen plant community. Impacts to the Ivesia sericoleuca along 

TKN-M2 from motorized vehicle use would be reduced, but not eliminated. Indirect impacts of risk of 

weed infestation and dust would still occur. Over the long term, the risk of cheatgrass spreading and outcompeting native vegetation including Ivesia sericoleuca along TKN-M2 is high. Refer to the weed risk 

assessment located in the project files for more information.

Epilobium howellii at the end of YRN-001 is at higher risk in Alternatives 2, 5, and 6. Barriers would

be placed at the end of YRN-001 to reduce impacts to Epilobium howellii and to the riparian vegetation 

growing adjacent to the pond. Implementation of the mitigations along these routes reduces the risk of 

significant impacts to the sensitive/watchlist species and/or watchlist plant communities. Alternative 7 
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does not propose the addition of routes TKN-M2 and YRN-001. Alternatives 3 and 4 do not propose the 

addition of routes TKN-J5, TKN-M2, or YRN-001. Sensitive species and aquatic/riparian plant 

communities along those routes benefit from the prohibition of motorized vehicle use on those routes.

B. Impacts to potential habitat:

Compared to Alternative 1, all action alternatives would reduce the number of perennial/intermittent 

water crossings and the miles of proposed additions to the NFTS located within 100 feet of riparian 

vegetation and thus reduce the risk of negative impacts to aquatic/riparian plant communities and those 

sensitive/watchlist species dependent on them. Of the action alternatives, Alternative 2 has the greatest 

risk of negatively impacting aquatic/riparian plant communities and the sensitive/watchlist species 

dependent on them. Alternative 2 proposes the addition of 28 water crossings, about 5 miles of route 

within 100 feet or riparian vegetation, and 2,649 acres of open area next to Boca, Stampede, and Prosser 

Reservoirs and in the Greenhorn area. Refer to Tables 3.06-5 and 3.06-6. However, even though much of 

the 2,649 acres is located within 100 feet of water, those acres support little riparian vegetation and have 

been surveyed and sensitive/watchlist species are not present. These “Open Areas” have a high risk of 

spreading weeds to other areas however.

Implementation of Alternatives 5 and/or 6 have a slightly smaller risk of negatively impacting 

aquatic/riparian plant communities and the sensitive/watchlist species dependent on them than Alternative 

2. Alternative 5 proposes the addition of 33 water crossings and about 7 miles of additions to the NFTS.

Alternative 6 proposes the addition of 36 water crossings and about 7 miles of additions to the NFTS.

Alternatives 5 and 6 do not propose the establishment of Prosser, Boca, Stampede or Greenhorn “Open 

Areas.” However, Alternative 6 does propose the establishment of access areas to Prosser, Boca, and 

Stampede Reservoirs (about 244 acres).

Alternatives 4 and 7 have less risk of negatively impacting aquatic/riparian plant communities and the 

sensitive/watchlist species dependent on them than Alternatives 2, 5 and 6. Alternative 7 proposes the 

addition of 14 water crossings and about 3 miles of additions to the NFTS. Alternative 4 proposes the 

addition of about 13 water crossings and about 3 miles of additions to the NFTS. Of the action 

alternatives, Alternative 3 has the least risk of negative impacts to sensitive/watchlist species dependent 

on aquatic/riparian plant communities because it does not propose the addition of any water crossings or 

miles to the NFTS and does not propose “Open Areas” or reservoir access areas. Alternative 3 provides 

the greatest benefits to sensitive/watchlist species dependent on aquatic/riparian plant communities that 

may occur within potential habitat.
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Table 3.06-5. Number of perennial and intermittent water crossings by alternative*

Action type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

1. Cross country travel 908 0 0 0 0 0 0

2. Additions 

to the NFTS

# of perennial and intermittent 

stream crossings

N/A 28 0 13 33 36 14

3. Establishment of Motorized “Open Areas”

(acres)

N/A 2,649 0 0 0 244 0

4. Changes 

to the NFTS

a. Change in Class of Vehicles 

resulting from approval of mixed 

use

No Effect

b. Change in Class of Vehicles 

resulting from changes in 

maintenance levels

No Effect

c. Change in Season of Use No Effect

d. Reopening Maintenance Level 

1 Roads 

0 0 0 0 46 3 0

5. Amendments to the Forest Plan No Effect

Total Crossings 3,389 2,509 2,481 2,497 2,604 2,529 2,495

*Crossings include lands under all ownerships.

The total includes crossings on State, County, and private roads. Alternative 1 total also includes unauthorized routes and closed 

NFTS roads still receiving some motorized use.

Table 3.06-6. Miles* of proposed additions to the NFS located within 100 feet of riparian vegetation by 

alternative

Action type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

1. Cross country travel 

(miles)

(acres)

146

134,222

0 0 0 0 0 0

2. Additions 

to the NFTS

Miles added within 100 feet of 

riparian

N/A 5 0 3 7 7 3

3. Establishment of Motorized “Open Areas” 

(acres for entire area)

N/A 2,649 0 0 0 244 0

4. Changes 

to the NFTS

a. Change in Class of Vehicles 

resulting from approval of mixed 

use

No Effect

b. Change in Class of Vehicles 

resulting from changes in 

maintenance levels

No Effect

c. Change in Season of Use No Effect

d. Reopening Maintenance Level 1 

Roads

0 0 0 0 6 1 0

5. Amendments to the Forest Plan No Effect

Total Miles

Total Acres

541

134,222

400

2,649

395

0

398

0

408

0

403

244

398

0

* Miles are approximate. Note that there are 141,396 acres located within 100 feet of riparian vegetation on the Forest but 7,174 of 

those acres are located in areas closed by the LRMP. The total mileage includes State, County, and private roads. Alternative 1 

total also includes unauthorized routes and closed NFTS roads still receiving some motorized use.
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Table 3.06-7. Proposed additions to the NFTS that pass through sensitive/watchlist occurrences and/or 

watchlist aquatic/riparian plant communities by alternative

Route ID Aquatic/riparian

vegetation

Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

SV-005 Aspen, seep/spring Yes No No Yes Yes No

SV-P14 Aspen Yes No Yes Yes Yes Yes

TKN-J2 Vernal pool Yes No Yes Yes Yes Yes

TKN-J5 Bruchia bolanderi, 

seep/spring

Yes No No Yes Yes Yes

TKN-J13 Aspen, seep/spring Yes No Yes Yes Yes but 

shortened

Yes

TKN-M2 Ivesia sericoleuca, aspen, 

seep/spring

Yes No No Yes Yes No

TKS-11 Aspen Yes No No Yes Yes Yes

YRN-001 Epilobium howellii Yes No No Yes Yes No

YRS-066 Seep/spring within 50 feet Yes No No Yes Yes No

YRS-SF4 Seeps/springs Yes No No Yes Yes No

YRS-SF5 Seep/spring Yes No Yes Yes Yes Yes

* Existing unauthorized routes and closed NFTS roads still receiving some motorized use listed here are also in Alternative 1.

3. Cumulative effects including reasonably foreseeable

Past/present/reasonably foreseeable future actions that could potentially affect or do affect 

aquatic/riparian plant communities and the sensitive/watchlist species dependent on them as well as the 

benefits from prohibiting public motorized use of routes are discussed. It is assumed that implementation 

of all of the action alternatives avoid significant long term cumulative impacts by implementing frequent 

and consistent evaluation of perennial and intermittent water crossings, implementing mitigations to 

reduce impacts to sensitive/watchlist species, and detection/treatment of weeds. This evaluation combined 

with rapid mitigation of resource damage/weed treatment avoids significant impacts to aquatic/riparian 

plant communities and the sensitive/watchlist species dependent on them in the long term.

Past: Management activities have occurred on Tahoe National Forest System (NFS) lands and 

privately owned lands for over a century, creating the existing condition as we see it. Historic 

management activities on NFS lands that impacted aquatic/riparian plant communities include: gold 

mining, gravel mining, hydroelectric development, land clearance, diversions of water for irrigation, land 

drainage, timber harvest, construction of roads and railroads, urbanization, livestock grazing, ground 

water abstraction, and others (Kondolf et al. 1996). This long history of disturbance to aquatic/riparian 

plant communities has contributed to the lack of an undisturbed reference for most aquatic/riparian 

dependent sensitive/watchlist species. Therefore, it is not possible to specifically quantify how these past 

management activities have impacted them. It is known that historic management activities altered 

springs, creeks, and rivers by diversion of water; that meadows, peatlands/fens were converted to other 

types of plant community when water was diverted and they dried out; that aquatic/riparian plant 

communities were repeatedly and heavily grazed by domestic livestock; and that numerous roads were 

built within RCAs changing the hydrology of the aquatic/riparian plant communities associated with 
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rivers and streams. These past management activities and others have cumulatively reduced the amount of 

aquatic/riparian plant communities within TNF watersheds that would be suitable habitat for the 

sensitive/watchlist species dependent on them. The amount of reduction is unknown.

In addition, aquatic/riparian plant communities were impacted when past management created 

conditions on the landscape that contributed to cross country travel. For example, skid trails and 

temporary roads that were created during past timber harvest projects are generally blocked off where 

they connect to system roads and trails once the project has been implemented. However, in a number of 

areas motorized vehicle users have removed or gone around the barriers that blocked access. Continued 

use of the old skid trail and/or temporary road created a motorized route that was not designed for 

continuous motorized use and may be located in an area that is not best suited to that use. For example, 

temporary crossings of streams are designed differently than permanent stream crossings. Trail planning 

and design – especially location – are important considerations for limiting disturbances to natural 

resources (Foltz and Meadows 2007) such as sensitive/watchlist species.

Current: It is recognized that current impacts to aquatic/riparian plant communities come from a 

variety of management activities - including motorized vehicle use. It is also recognized that motorized 

vehicle use within aquatic/riparian plant communities and their zones of influence (RCAs) negatively 

impacts the soil/vegetation/water in those site specific areas. For example, use of roads/trails/areas while 

the soils are wet can cause the formation of ruts/wheel tracks that can channel water away from the 

vegetation located near the rut. The channeled water frequently runs down the road or trail altering area 

hydrology and causing erosion of soil. Aquatic/riparian vegetation located in areas of changed hydrology 

and soil erosion often has reduced vigor and may die if the changes are severe.

Aquatic/riparian vegetation located within 30 feet of the road/trail can also be negatively impacted 

when it is run over as users park along the road/trail, or pull over to let others pass. Aquatic/riparian 

vegetation located within 100 feet of the route can be covered in dust causing a loss of plant growth.

Water quality can also be negatively impacted when motorized vehicles add sediment and other pollutants 

to aquatic plant communities. (Refer to Section 3.02 for more information about impacts to soil and 

water.) Motorized vehicle use within aquatic/riparian plant communities and their zones of influence does 

not benefit soil, water and native vegetation within those areas. However, the significance of the negative 

impacts to soil/vegetation/water within specific aquatic/riparian plant communities varies. Refer to 

Appendix A (Site Specific Road, Trail and Open Area Information) for additional information about 

aquatic/riparian plant communities that are impacted by motorized vehicles.

Other on-going projects on the Forest that impact aquatic/riparian plant communities include: special 

uses projects such as utility corridor construction and maintenance (utility lines pass through and impact 

many different types of plant communities including aquatic/riparian); minerals operations that remove 

native vegetation and recontour the landscape; and livestock grazing projects (impacts to aquatic/riparian 

plant communities as livestock eat the vegetation and punch hoof holes into the soil). These on-going 

impacts to aquatic/riparian vegetation contribute to cumulative effects to these plant communities.

Surveys of over 95 miles and many acres of proposed additions to the NFTS showed that there are 

occurrences of sensitive/watchlist species and/or aquatic/riparian watchlist plant communities that are 
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negatively impacted by motorized vehicle use of NFTS routes, unauthorized routes, and by cross country 

use. Examples of these impacts are discussed below:

Example 1: Meesia triquetra is a sensitive moss that is dependent on aquatic/riparian plant 

communities called peatlands or fens. An occurrence of Meesia triquetra is currently being impacted by 

cross country motorized vehicle travel in Summit fen. Cross country travel onto the fen created bare soil 

by killing the vegetation where the wheel tracks occurred. In addition, Summit fen is also being indirectly 

impacted by the system route located within 100 feet above it. The system route is channeling water and 

sediment into the fen covering vegetation with sediment and creating bare soil areas. In addition, the 

addition of sediment may be changing the acidity of the water (pH) in the fen (formal monitoring of the 

water pH and possible peat loss has not occurred). It is known that damage to fens/peatlands from 

motorized vehicle use alters surface and subsurface flow patterns and can result in areas of bare peat and 

soil. Areas of exposed (bare) peat are at increased risk of drying out and decomposing. Wheel tracks can 

also weaken or destroy the rhizomatous root network of the clonal peat forming plants. Functioning 

fens/peatlands store carbon. Loss of moisture to the fen/peatland (from water being channeled down the 

road/trail) could cause the plants that make up this fen to die releasing carbon. Peat forming wetlands 

(such as Summit fen) also provide important benefits within TNF watersheds by improving water quality 

and providing habitat for unique plant communities. Because of the large historical loss of this type of 

plant community, remaining fens are considered rare. 

Example 2: Ivesia sericoleuca and Ivesia aperta var. aperta occurrences are located on the eastside 

of the Forest in meadows and vernally wet areas (meadows and vernally wet areas also considered 

aquatic/riparian plant communities). Cross country motorized vehicle use has negatively impacted 

occurrences of these sensitive plants in several locations. Motorized vehicles have created ruts within 

occurrences that act as channels taking water and soil away from the sensitive plant occurrences. Several 

plants show pedestaling – where the body of the plant appears to be “perched” above the soil level. In 

addition, motorized vehicles have killed and/or injured individual plants by driving over them. Plants 

located within wheel tracks show reduced vigor – are much smaller than those located outside of wheel 

track areas.

Reasonably foreseeable: When past and current impacts are added to the impacts of the reasonably 

foreseeable future actions identified in Appendix H (Reasonably Foreseeable Projects and Cumulative 

Effects), risks to aquatic/riparian plant communities and the sensitive/watchlist species dependent on 

them increase.

Some current and reasonably foreseeable management actions do not impact aquatic/riparian plant 

communities and others are expected to have minimal direct impacts. For example, fuel reduction/timber 

harvest projects routinely establish a 50-100 foot buffer around aquatic/riparian plant communities (such 

as riparian vegetation along streams, peatlands, fens, springs, and seeps) where no management activities 

are implemented. This buffer is designed to reduce and/or eliminate direct/indirect impacts to 

aquatic/riparian plant communities and/or the sensitive/watchlist species that occur within them. Other 

projects such as conifer removal from aspen plant communities are designed to improve the health of 

aspen by improving its reproduction. Aspen conifer removal projects do not buffer riparian vegetation 
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from disturbance but attempt to limit the amount of disturbance within those aquatic/riparian plant 

communities. Therefore impacts to riparian vegetation and other riparian resources are expected to be 

minimal.

No Action: Implementation of Alternative 1 carries a high risk of cumulative impacts to 

sensitive/watchlist species dependent on aquatic/riparian plant communities. Since (in general terms) no 

restrictions would be in place to limit where motorized vehicle use could occur, all aquatic/riparian plant 

communities and sensitive/watchlist species dependent on them that grow in areas that are accessible by 

motorized vehicles would be at risk. Since complete surveys for the Forest are not available, and an 

undisturbed reference for aquatic/riparian plant community dependent sensitive/watchlist species is also 

lacking, this analysis focuses on cumulative impacts to aquatic/riparian plant communities without current 

botanical surveys and discussion of cumulative impacts to individual species where cross country 

travel/motorized vehicle use is known to impact them.

When the impacts of all past, current and reasonably foreseeable management actions are added to the 

possible impacts of implementing Alternative 1, (especially cross country travel) the potential to 

significantly impact (long term – over 5 years) aquatic/riparian plant communities and the 

sensitive/watchlist plant species dependent on them is high. Cumulative impacts include possible 

conversion of peatlands/fens and other wetlands to other types of plant communities from altered 

hydrology, soil erosion, and weed infestation. Aquatic/riparian plant communities frequently lack the 

vegetative barriers to keep motorized vehicle use from accessing them (for example wet meadow areas).

Therefore, under Alternative 1, it is reasonable to expect cross country motorized vehicle use within them.

Several examples of how uses of system and unauthorized routes, and cross country travel impact 

sensitive/watchlist species in aquatic/riparian plant communities are provided below. These examples are 

provided to give the reader information about the types of impacts that could occur with cross country

motorized vehicle travel.

Example – Bruchia bolanderi: Bruchia bolanderi is currently indirectly/cumulatively impacted by 

motorized vehicle use in several locations. This sensitive moss occurs along Castle Creek and is located 

about 50 feet upstream and 30 feet downstream from the Castle Creek stream crossing along TKN-J5. 

There are limited numbers of this moss known to occur on the TNF. Known occurrences include Castle 

Valley, Summit fen, Round Valley meadow, and Upper Lola Montez areas. Both the Upper Lola Montez 

and Castle Creek occurrences are being impacted by motorized vehicles. In addition, TKN-J5 channels 

water and has altered the hydrology of site specific areas along it. Impacts are not currently considered 

significant. However, if motorized vehicle use causes significant hydrologic alternation or soil 

compaction, the moss occurrences could be lost. All occurrences of this moss on the TNF are small in 

area and could be significantly reduced by one vehicle pass. Implementation of Alternative 1 carries a 

high risk (short and long term) that motorized vehicles could significantly impact Bruchia bolanderi moss 

occurrences since they are all located in areas that are fairly accessible to motorized vehicles. In addition, 

over the long term, weeds could be introduced into the wet meadow plant community containing Bruchia 

bolanderi. If weeds were to become established in the Bruchia bolanderi locations, the sensitive moss 

plants would be lost. When, where, and if weeds would become established is unknown. 
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Example – Ivesia sericoleuca: Ivesia sericoleuca was discovered along TKN-M2. Cross country 

motorized vehicle use has killed and injured individual plants within this occurrence. These impacts are 

not considered significant at this time. However, over the long term, impacts to Ivesia sericoleuca

occurrences from cross country travel by motorized vehicles may be significant.

Most of the known occurrences of Ivesia sericoleuca are known to be impacted by a combination of 

motorized and non-motorized vehicles, livestock grazing and/or cheatgrass invasion. Even though there 

are tens of thousands of Ivesia sericoleuca plants known to occur on Tahoe NFS lands, the majority are 

being negatively impacted. Ivesia sericoleuca plants grow in meadow plant communities where terrain 

and vegetation do not provide obstacles to cross country travel. TNF occurrence records for the 28 known 

occurrences indicate that 18 of the known occurrences are negatively impacted by off-highway vehicles 

(OHVs). Only two occurrence records indicate no disturbances. Twenty of the 28 occurrence records

indicate that livestock grazing is a negative disturbance. Over the long term, cross country travel by 

motorized vehicles in these plant communities, combined with past/current impacts could significantly 

reduce the number of Ivesia sericoleuca plants on the TNF. In addition, over the long term, other 

occurrences of sensitive species, such as Ivesia aperta var. aperta and Pyrrocoma lucida, which are 

accessible by motorized vehicles traveling cross country could also be significantly reduced. Occurrences 

of all three of these sensitive plants are currently known to be negatively impacted by motorized vehicle 

use. Refer to the occurrence records for these plants located in the Supervisor’s Office. 

Example – Populus tremuloides/aspen: Aspen clones (watchlist plant communities) were found 

along several routes including TKN-M2, TKS-11, SV-005, and SV-P14. Over the long term, cross country 

travel could damage aspen so much that the aspen are killed and/or weakened. Weakened aspen are more 

susceptible to disease and/or insect infestation. Cross country travel through aspen stands could alter soil 

properties. Shepperd et al. (2006) reported that recreation activities can alter soil properties if continued 

vehicle passes cause the stripping of small moisture-absorbing roots from large lateral roots. Severe 

motorized vehicle use could increase runoff from storm events in these aspen clones increasing erosion 

(Shepperd et al. 2006). Over the long term (more than 5 years), continued motorized vehicle use within 

aspen could introduce disease, spread weeds so that regeneration is reduced, and increase the risk of loss 

of these plant communities.

Example – wet meadows: Some system and unauthorized motorized vehicle roads/trails end at the 

edge of wet meadows. For example, YRN-11 is an unauthorized road that ends at a wet meadow. There is 

evidence (wheel tracks) that some motorized users are driving past the end of the route onto the meadow.

When motorized vehicle use occurs in wet meadows, soils are compacted, the hydrology is altered, and 

vegetation is killed. Implementation of Alternative 1 would not place barriers at the end of unauthorized 

trails such as YRN-11 and it is reasonable to assume that cross country travel across wet meadows would 

occur. Restoration of aquatic/riparian plant communities such as wet meadows is often time consuming 

and expensive and successful methods of reintroduction of sensitive/watchlist species are not always 

available.

Alternative 1 has the greatest number of perennial and intermittent water crossings, the most miles of 

motorized vehicle roads/trails/areas within 100 feet of riparian vegetation, and allows cross country 
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travel. Refer to Tables 3.06-5 and 3.06-6. In addition, implementation of Alternative 1 has the greatest risk 

of introducing and spreading weeds into aquatic/riparian habitats (Refer to the Noxious Weed Risk 

Assessment located in the project files).

Given all of the above information, implementation of Alternative 1 may impact Botrychium 

ascendens, Botrychium crenulatum, Botrychium lunaria, Botrychium minganense, Botrychium montanum, 

Bruchia bolanderi, Epilobium howellii, Fissidens aphelotaxifolius, Helodium blandowii, Hydrothyria 

venosa, Ivesia aperta var. aperta, Ivesia aperta var. canina, Ivesia sericoleuca, Ivesia webberi, Meesia 

triquetra, Meesia uliginosa, and Pyrrocoma lucida and may contribute to a trend for listing them as 

threatened or endangered over the long term. Implementation of Alternative 1 may also impact Androsace 

occidentalis var. simplex, Darlingtonia californica, Drosera anglica, Drosera rotundifolia, Juncus 

marginatus var. marginatus, Mimulus lacinatus, Potamogeton filiformis, Rhynchospora alba, 

Rhynchospora capitellata, Scutellaria galericulata, Sphagnum species, Utricularia minor, Veronica 

cusickii, special aquatic features and aspen groves. At this time, impacts to watchlist plants and/or plant 

communities are not considered significant unless entire plant communities are lost. Based on current 

information, watchlist plants/plant communities that are aquatic/riparian dependent are not at risk of being 

lost in the short term (less than 5 years). The number of aquatic/riparian plant communities that could be 

converted to other types of plant communities due to cross country motorized vehicle use is unknown. It 

is also unknown how such variables as climatic variation and future water demands from NFS lands 

combined with cross country motorized travel would impact aquatic/riparian plant communities. It is 

known that implementation of Alternative 1 could continue to negatively impact these limited plant 

communities. Refer to the watchlist report located in the project record. It is believed that implementation 

of Alternative 1 puts these plant communities at risk of being lost in the long term.

Action alternatives: Implementation of the action alternatives would cumulatively impact aquatic/

riparian plant communities and the sensitive/watchlist species dependent on them. When the impacts of 

all past, current and reasonably foreseeable management actions are added to the possible impacts of 

adding intermittent/perennial water crossings and miles of road/trail/area located within 100 feet of 

riparian vegetation, there is the potential to significantly impact (long term – over 5 years) them.

However, as discussed previously, mitigations have been developed for those proposed additions to the 

NFTS that have current surveys (over 95 miles).

Motorized vehicle use of proposed additions that lack current surveys may be impacting sensitive/

watchlist species and/or aquatic/riparian plant communities. Direct/indirect impacts could be significant 

in the long term if sensitive/watchlist species and/or aquatic/riparian plant communities are lost. Impacts 

could also be significant over the long term if sensitive/watchlist species and/or aquatic/riparian plant 

communities are replaced by weeds. Currently there are no cost effective mitigations available to prevent 

the introduction of weeds from motorized vehicle use along roads/trails and within areas. Since the 

existing condition of the proposed additions without current surveys is unknown, the following alternative 

comparison is done for impacts to known occurrences and potential habitats.

Alternative 2: Of the action alternatives, Alternative 2 has the greatest risk of cumulatively impacting

aquatic/riparian plant communities and the sensitive/watchlist species dependent on them. Alternative 2 
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proposes the addition of 28 water crossings, about 5 miles of route within 100 feet of riparian vegetation, 

and 2,649 acres of ”Open areas” next to Boca, Stampede, and Prosser Reservoirs and in the Greenhorn 

area. These “Open Areas” have a high risk of spreading weeds to other areas.

Implementation of Alternative 2 would also impact known occurrences of sensitive/watchlist species 

and/or aquatic/riparian plant communities along proposed additions. Mitigations have been developed to 

reduce and/or eliminate impacts to known occurrences; however, known occurrences are still at risk from 

indirect impacts such as dust and weed infestation. There are no mitigations available that effectively 

reduce the indirect impacts of increased risk of weed introduction/spread and reduced vigor due to dust. 

Motorized vehicle use along proposed additions that have weed infestations and sensitive/watchlist 

species and/or aquatic/riparian plant communities have the greatest risk that these species and/or plant 

communities would be infested with weeds over time. In addition, sensitive/watchlist species located 

within 100 feet of proposed additions are at increased risk of reduced vigor from dust. Dust covered 

plants do not reproduce or grow as well as those plants that are not covered in dust. Dust covered plants 

could be weakened to the point that they can no longer compete effectively with weeds or other 

vegetation. The amount of dust is dependent on many variables such as the amount of use, the type of 

soil, wind patterns, etc. Over the long term, competition for soil and water due to weed invasion and 

weakening of plants due to being covered with dust could kill plants. However, frequent field visits with 

rapid implementation of mitigations to reduce/eliminate impacts (including weed treatment) are expected 

to reduce the significance of these impacts. Therefore, impacts to known occurrences and/or potential 

habitats without current botanical surveys from implementation of Alternative 2 are not considered 

significant.

Alternatives 5 and 6: Implementation of Alternatives 5 and/or 6 have a slightly smaller risk of 

cumulatively impacting aquatic/riparian plant communities and the sensitive/watchlist species dependent 

on them than Alternative 2. Alternative 5 proposes the addition of 33 water crossings, about 7 miles of 

additions to the NFTS and reopens the most miles of ML 1 roads (about 46 miles) in aquatic and riparian 

communities. Alternative 6 proposes the addition of 36 water crossings, about 7 miles of additions to the 

NFTS and reopens about 3 miles of ML 1 roads in this community type. Alternatives 5 and 6 do not 

propose the same additions of Prosser, Boca, Stampede or Greenhorn “Open Areas” - Alternative 6 

proposes 244 acres and Alternative 5 proposes no “Open Areas.” Therefore, Alternative 2 has a higher 

risk of weed spread than Alternatives 5 and 6.

Implementation of Alternatives 5 and 6 would also impact known occurrences of sensitive/watchlist 

species and/or aquatic/riparian plant communities along proposed additions. Known occurrences are still 

at risk from indirect impacts such as dust and weed infestation. Frequent field visits with rapid 

implementation of mitigations to reduce/eliminate impacts (including weed treatment) are expected to 

reduce the significance of these impacts. Therefore, impacts to known occurrences and/or potential 

habitats without current botanical surveys from implementation of Alternatives 5 and 6 are not considered 

significant.

Alternatives 4 and 7: Implementation of Alternatives 4 and 7 cumulatively impacts aquatic/riparian 

plant communities and the sensitive/watchlist species dependent on them. However, these cumulative 
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impacts are less than those under Alternatives 2, 5 and 6. Alternative 7 proposes the addition of 14 water 

crossings, about 3 miles of additions to the NFTS and does not have any water crossings associated with 

the reopening of any ML 1 roads. Alternative 4 proposes the addition of about 13 water crossings, about 3 

miles of additions to the NFTS and does not have any water crossings associated with the reopening of 

any ML 1 roads. In addition, the amount of indirect impacts that known occurrences would experience is 

reduced in Alternatives 4 and 7 because they do not propose additions of specific routes with known 

occurrences. Implementation of Alternative 4 would not indirectly impact Bruchia bolanderi and the seep 

along TKN-J5; Ivesia sericoleuca, a spring, and aspen along TKN-M2; or aspen along TKS-11 and SV005 because these routes are not proposed for addition to the NFTS under Alternative 4. Aspen along SVP14 would continue to be indirectly impacted under Alternative 4. In addition, implementation of 

Alternative 4 would not spread cheatgrass along TKN-M2 through motorized vehicle use since motorized 

vehicle use of that route would be prohibited. Alternative 7 would continue to indirectly impact Bruchia 

bolanderi and the seep along TKN-J5 and aspen along TKS-11 and SV-P14. Alternative 7 would not 

impact Ivesia sericoleuca, a spring and aspen along TKN-M2, or continue to spread cheatgrass along 

TKN-M2.

Alternative 3: Implementation of Alternative 3 would cumulatively impact aquatic/riparian plant 

communities and those sensitive/watchlist species dependent on them through use of system routes. Of 

the action alternatives, Alternative 3 has the least risk of negative impacts to sensitive/watchlist species 

dependent on aquatic/riparian plant communities because it does not propose the addition of any water 

crossings or miles to the NFTS and does not propose “Open Areas.” Implementation of Alternative 3 has 

the lowest weed risk of the action alternatives and provides the greatest benefit to aquatic/riparian plant 

communities and those sensitive/watchlist species dependent on them.

Given the above information, implementation of the action alternatives could impact: Botrychium 

ascendens, Botrychium crenulatum, Botrychium lunaria, Botrychium minganense, Botrychium montanum, 

Bruchia bolanderi, Epilobium howellii, Fissidens aphelotaxifolius, Helodium blandowii, Hydrothyria 

venosa, Ivesia aperta var. aperta, Ivesia aperta var. canina, Ivesia sericoleuca, Ivesia webberi, Meesia 

triquetra, Meesia uliginosa, or Pyrrocoma lucida but would not contribute to a trend for listing them as 

threatened or endangered. Implementation of the action alternatives could also impact Androsace 

occidentalis var. simplex, Darlingtonia californica, Drosera anglica, Drosera rotundifolia, Juncus 

marginatus var. marginatus, Meesia longiseta, Mimulus lacinatus, Potamogeton filiformis, Rhynchospora 

alba, Rhynchospora capitellata, Scutellaria galericulata, Sphagnum species, Utricularia minor, Veronica 

cusickii, special aquatic features and aspen groves but those impacts are not expected to be significant in 

the short or long term. Since it is assumed that motorized vehicle users would stay on designated routes 

regardless of the action alternative selected, and motorized vehicle use does not benefit aquatic/riparian 

plant communities, the alternative with the least number of miles within and adjacent to aquatic/riparian 

plant communities is the most beneficial to those plant communities and the resources dependent on them, 

i.e. Alternative 3.
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

614 – Tahoe National Forest

Serpentine and/or Copper/Heavy Metal Plant Communities

1. Prohibition of cross country travel

Indicator(s) used to measure effects:

• Acres where cross country travel is prohibited (thereby reducing the mileage of routes available 

for motorized use) Mileage reduction includes unauthorized routes and closed NFTS roads still 

receiving some motorized use located within 100 feet of serpentine and/or copper/heavy metal 

plant communities. 

No Action: Alternative 1 does not prohibit cross country travel on the 14,412 acres of serpentine soil 

within the TNF. Under implementation of Alternative 1 as yet undiscovered serpentine/copper/heavy 

metal dependent sensitive/watchlist species and/or plant communities could be negatively impacted by 

motorized vehicle use if they are located in areas accessible by vehicles. It is reasonable to expect that 

over time, cross country use would kill or injure sensitive/watchlist species and significantly impact 

serpentine plant communities. Cross country use in these plant communities could increase soil erosion. 

The significance of direct/indirect impacts is dependent on many factors including the amount of 

disturbance, the sensitive/watchlist species being impacted, and in some cases, the season when the 

disturbance takes place. The significance of impacts is also dependent on the number of sensitive/ 

watchlist species that occur in a specific location and how many of them are damaged. For example, some 

serpentine dependent sensitive species, such as Mielichhoferia elongata and Monardella follettii, have not 

been found on the TNF. If they were found in/along proposed additions to the NFTS, the occurrence 

would be considered an important range extension of the species and disturbances could be considered 

significant.

The TNF has about 80 miles of NFTS roads/trails open to motor vehicle use and 40 miles of 

unauthorized routes and closed NFTS roads still receiving some motorized use located within serpentine 

plant communities. About 1 mile of unauthorized route is located within an area closed to motorized 

vehicle travel by existing forest order. Since serpentine plant communities are sparsely vegetated, under 

Alternative 1, motor vehicles could access almost all of these communities via cross country travel.

Dependent on many factors such as amount of motor vehicle use, amount of erosion, and amount of 

vegetation loss, impacts could be significant over the long term.

No sensitive species were found in the surveys of about 95 miles of unauthorized routes and closed 

NFTS roads still receiving some motorized use. An occurrence of the watchlist plant Erigeron petrophilus

var. sierrensis was found within and along YRN-7. This is the only occurrence of this plant known on the 

TNF. Motorized vehicle use of YRN-7 is directly/indirectly impacting about 50% of the plants within the 

occurrence since about 50% of the plants are located within 100 feet of wheel tracks of YRN-7.

Implementation of Alternative 1 could significantly reduce the size of this occurrence and/or kill all of 

these plants through cross country travel since the occurrence area is sparsely vegetated and there is 

evidence of cross country travel currently. Loss of the only occurrence of Erigeron petrophilus var. 

sierrensis on the TNF would be significant.
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

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Action alternatives: All of the action alternatives prohibit cross country travel. Therefore, direct/

indirect impacts to sensitive/watchlist species dependent on these plant communities from cross country 

travel would not occur. Since unauthorized routes and continued motorized use of closed NFTS roads are 

considered an expression of cross country travel, the number of miles where motorized vehicle use is 

prohibited provides benefits to these plant communities. Alternatives 2 and 5 prohibit motorized use on 

the fewest miles of unauthorized routes and closed NFTS roads still receiving some motorized use of the 

action alternatives – about 36 miles or 90 percent. Alternatives 4 and 7 prohibit public motorized use on 

about 37 miles of unauthorized routes and closed NFTS roads still receiving some motorized use or 93

percent. Alternatives 3 and 6 prohibit public motorized use on 100 percent of the unauthorized routes and 

closed NFTS roads still receiving some motorized use located within serpentine/copper/heavy metal plant 

communities and would have the least risk of indirect and cumulative impacts to sensitive/watchlist 

species dependent on these plant communities.

2. Additions to the NFTS and Reopening ML 1 Roads

Indicator(s) used to measure effects:

• Miles of proposed additions to the NFTS that pass through serpentine (ultramafic) soils. Areas of 

copper/heavy metal soils are usually small and not identified as distinct soil mapping units. 

Therefore, the miles of unsurveyed proposed motorized vehicle road/trail/area in copper and 

heavy metal areas are not known. Areas of copper/heavy metal are identified during on the 

ground surveys.

• Sensitive/watchlist species located within 100 feet of proposed additions to the NFTS and/or 

miles of potential habitat lacking current surveys.

No Action: Alternative 1 does not propose additions to the NFTS; however, implementation of 

Alternative 1 could impact sensitive/watchlist species and/or serpentine/copper/heavy metal plant 

communities directly, indirectly, and cumulatively by continuing use of about 40 miles of unauthorized 

routes and closed NFTS roads, continuing use of the 80 miles of open NFTS roads/trails, state, county, 

and private routes, and allowing cross country travel within these plant communities. These impacts could 

be significant dependent on the species of plant, amount of disturbance, etc. Refer to the discussion above 

under the No Action Alternative for information about the effects of cross country travel.

Action alternatives: Compared to Alternative 1, all action alternatives would reduce the number of 

miles open for motorized vehicle use within serpentine/copper/heavy metal plant communities. Refer to 

Table 3.06-8.

A. Impacts to known occurrences: No sensitive species were found in surveys of proposed additions 

located within serpentine/copper/heavy metal plant communities. However, an occurrence of the watchlist 

plant Erigeron petrophilus var. sierrensis was found within and along YRN-7. Motorized vehicle use of 

YRN-7 is directly/indirectly impacting about 1⁄2 of the plants within this occurrence since about 50 percent 

of them are located within 100 feet of the route. Loss of 50 percent of the only known occurrence of this

plant on the TNF would be significant. Therefore, mitigations were developed to reduce direct impacts.

Barriers would be placed along both sides of YRN-7 where it passes through the occurrence. Indirect 
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616 – Tahoe National Forest

impacts from dust and increased weed risk would continue. Therefore, those alternatives that propose the 

addition of YRN-7 have the greatest risk of indirect impacts to this plant. Alternatives 2, 5 and 7 propose 

the addition of YRN-7 to the NFTS. Alternatives 3, 4 and 6 do not propose YRN-7.

B. Impacts to potential habitat: Alternatives 2 and 5 propose the addition of about 4 miles, the most 

miles within this plant community. Alternatives 4 and 7 both propose the addition of about 3 miles of 

route within these plant communities. Alternatives 3 and 6 do not propose the addition of any routes 

within serpentine plant communities and therefore have the least risk of negative impacts to native plants 

including sensitive and watchlist species located within these plant communities.

Table 3.06-8. Miles* of road/trail/area within serpentine plant communities by alternative

Action type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

1. Cross country travel 

(miles located within serpentine plant communities)

(acres located within serpentine plant communities)

40

14,412

0 0 0 0 0 0

2. Additions to 

the NFTS

Miles added within 100 feet of 

serpentine (ultramafic ) soil

N/A 4 0 3 4 0 3

3. Establishment of Motorized “Open Areas” 

(acres)

N/A 0 0 0 0 0 0

4. Changes to 

the NFTS

a. Change in Class of Vehicles 

resulting from approval of 

mixed use

No Effect

b. Change in Class of Vehicles 

resulting from changes in 

maintenance levels

No Effect

c. Change in Season of Use No Effect

d. Reopening Maintenance 

Level 1 Roads 

0.0 0.0 0.0 0.0 0.2 0.2 0.0

5. Amendments to the Forest Plan No Effect

Total Miles

Total Acres

120

14,412

85

0

81

0

84

0

85

0

84

0

84

0

*Miles are approximate. The total mileage includes NFTS, State, County, and private roads. Alternative 1 total also includes 

unauthorized routes and closed NFTS roads still receiving some motorized use.

3. Cumulative effects including reasonably foreseeable

Indicator(s) used to measure effects: Past/present/reasonably foreseeable future actions that could 

potentially impact serpentine/copper/heavy metal plant communities as well as the sensitive/watchlist 

species dependent on them, including the benefits from prohibiting use of unauthorized routes and closed 

NFTS roads still receiving some motorized use are discussed. It is assumed that all of the action 

alternatives avoid significant long term cumulative impacts by implementing frequent evaluation of 

routes, implementing mitigations to reduce impacts to sensitive/watchlist species, and conducting weed 

detection surveys with rapid treatment of weeds. This route evaluation combined with rapid mitigation of 

resource damage avoids significant impacts to serpentine/copper/heavy metal plant communities and the 

sensitive/watchlist species dependent on them in the short and long term. 
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Past: Serpentine habitats in the Sierra Nevada have been reduced in area and/or have had their 

functions impaired. Gold mining, timber harvest, road construction, recreational uses, and gravel mining 

are a few of the management activities that have impacted the serpentine habitats on the TNF. 

Serpentine habitats are frequently open terrain (Kruckeberg 1984). Therefore they lack vegetation to 

prevent cross country travel by motorized vehicles. Allium sanbornii var. congdonii, Allium sanbornii var. 

sanbornii, Chlorogalum grandiflorum, Mielichhoferia elongata, Monardella follettii and Perideridia 

bacigalupi are the sensitive/watchlist species that are considered dependent on serpentine/copper/heavy 

metal habitats. Historic activities have cumulatively reduced the quality of serpentine habitat that would 

be suitable for these plants within TNF watersheds. The amount of reduction is unknown.

Current: Current management (2004 on) has added to cumulative impacts to 

serpentine/copper/heavy metal plant communities primarily through continued mining operations, utility 

corridor maintenance, and motorized vehicle use. Current management for sensitive/watchlist species 

being negatively impacted by motorized vehicle use has involved blocking the access with wooden and/or 

rock barriers. This method has not always been effective since the lack of vegetation in these plant 

communities allow access around the barriers. However, this analysis assumes that users would stay on 

routes and would not use routes where motorized vehicle use is prohibited.

Special uses projects such as utility corridor construction and maintenance pass through and impact 

many different types of plant communities including serpentine/copper/heavy metal. Mining/minerals 

projects are also known to impact serpentine/copper/heavy metal plant communities - and eliminate 

significant amounts of vegetation in some areas. Most of the serpentine plant communities on the TNF are 

considered disturbed, primarily by historic mining. 

Reasonably foreseeable: Serpentine plant communities are cumulatively impacted when past 

impacts, the impacts of implementing the alternatives, and on-going impacts are added to the impacts of 

those actions identified in Appendix H (Reasonably Foreseeable Projects and Cumulative Effects).

However, the reasonably foreseeable actions identified in Appendix H are not located in or near 

serpentine/copper/heavy metal plant communities. Therefore, the reasonably foreseeable projects listed in 

Appendix H are not expected to add to the cumulative impacts that serpentine/copper/heavy metal plant 

communities on the TNF experience.

No Action: Implementation of Alternative 1 carries a high risk of cumulative impacts to 

sensitive/watchlist species dependent on serpentine/copper/heavy metal plant communities. Since (in 

general terms) no restrictions would be in place to limit where motorized vehicle use could occur, all 

serpentine/copper/heavy metal plant community dependent sensitive/watchlist species would be at risk.

These plant communities are frequently open terrain (Kruckeberg 1984) and lack vegetation to prevent 

cross country travel by motorized vehicles. In addition, Alternative 1 does not prohibit motorized vehicle 

use on unauthorized routes and closed NFTS roads still receiving some motorized use. When the impacts 

of all past, current and reasonably foreseeable management actions are added to the possible impacts of 

cross country travel, implementation of Alternative 1 has the potential to significantly impact 

serpentine/copper/heavy metal plant communities and the sensitive/watchlist species dependent on them. 

Implementation of Alternative 1 may impact Mielichhoferia elongata and Monardella follettii if they 
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

618 – Tahoe National Forest

occur on the unsurveyed potential habitat and may contribute to a trend for listing them as federally listed 

as threatened or endangered over the short or long term. Neither species has been found on TNF system 

lands. Therefore discovering either species on the TNF would make them important occurrences and 

impacts to them could be significant. Implementation of Alternative 1 may also impact Allium sanbornii

var. congdonii, Allium sanbornii var. sanbornii, Chlorogalum grandiflorum, and Perideridia bacigalupi,

but those impacts are not considered significant at this time even though cross country travel could 

negatively impact entire occurrences if they exist in the potential habitat that lacks current botanical 

surveys. Refer to the Biological Evaluation for Sensitive Plants and Fungi and the Watchlist Plant and 

Plant Community Report located in the project record more discussion of the past, current and reasonably 

foreseeable actions that contribute to cumulative impacts to serpentine/copper/ heavy metal plant 

communities. Over the long term, with cross country travel and other continued disturbances, some of the 

serpentine plant communities may lose significant amounts of vegetation and experience increased 

erosion. This could be locally significant and may be regionally significant over the long term since 

serpentine plant communities/areas of copper/heavy metals are limited in distribution and are known to 

have a high number of endemic plants.

Action alternatives: Compared to Alternative 1, all action alternatives would reduce the number of 

miles of road/trail open for public motorized use in serpentine/copper/heavy metal plant communities. 

However, implementation of the action alternatives could add to cumulative impacts experienced by 

sensitive/watchlist species dependent on serpentine/copper/heavy metal plant communities. Surveys to 

date have not detected any sensitive species along proposed additions to the NFTS. However, the 

watchlist plant Erigeron petrophilus var. sierrensis was discovered within and adjacent to YRN-7.

The action alternatives propose 8 routes that pass through serpentine soils. Two of the 8 are ML 1 or 

temporary route proposed additions in Alternative 5 only. The other routes are identified as: ARM-2, 

ARM-3r, YRN-509, YRN-7, and YRN-M2.

Alternatives 2 and 5: Cumulative impacts from implementations of Alternatives 2 and 5 are not 

considered significant. Of the action alternatives, implementation of Alternatives 2 and 5 propose the 

most miles of route in these plant communities and restrict public use of the fewest miles of unauthorized 

routes and closed NFTS roads still receiving some motorized use in these plant communities. Therefore, 

implementation of Alternatives 2 and 5 have the greatest risk of cumulatively impacting sensitive and/or 

watchlist species dependent on serpentine/copper/heavy metal plant communities of the action 

alternatives. The risk of cumulative impacts to serpentine plant communities is higher in Alternative 5 

than in Alternative 2 because the ML 1 and temporary routes proposed under Alternative 5 do not have 

current surveys. Therefore, the risk of cumulatively impacting occurrences of sensitive/watchlist plants 

dependent on these plant communities (should they occur in the unsurveyed habitat) is less in Alternative 

2 than in Alternative 5. All serpentine/cooper/heavy metal dependent sensitive/watchlist plants would

have mitigations implemented to reduce and/or eliminate impacts from motorized vehicles when they are 

discovered. The management requirements (mitigations) for the known occurrence of Erigeron 

petrophilus var. sierrensis located immediately adjacent to YRN-7 are identified in Appendix A (Site 

Specific Road, Trail and Open Area Information). It is believed that these management requirements 
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

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would reduce (but not eliminate impacts to Erigeron petrophilus var. sierrensis plants from motorized use 

of YRN-7. In addition, serpentine/copper/heavy metal dependent rare plants could go undetected under 

implementation of Alternative 5 along routes without current botanical surveys.

Alternatives 4 and 7: Cumulative impacts from implementation of Alternatives 4 and 7 are not 

considered significant. Alternatives 4 and 7 both propose about 3 miles of additions to the NFTS within 

these plant communities and do not propose ML 1/temporary roads without current botanical surveys. 

Alternatives 4 and 7 prohibit motorized vehicle use of 37 miles of unauthorized routes and closed NFTS 

roads still receiving some motorized use within these plant communities. Sensitive/watchlist species 

would be indirectly impacted, but would have mitigations implemented to reduce/eliminate direct impacts 

to them under implementation of Alternatives 4 and 7 (should they occur in the unsurveyed habitat). 

Therefore, implementation of Alternatives 4 and 7 could indirectly and cumulatively impact 

Mielichhoferia elongata and Monardella follettii if they occur on the unsurveyed potential habitat, but 

would not contribute to a trend for federally listing them as threatened or endangered. Implementation of 

Alternatives 4 and 7 may also indirectly and cumulatively impact Allium sanbornii var. congdonii, Allium 

sanbornii var. sanbornii, Chlorogalum grandiflorum, and Perideridia bacigalupi, but those impacts are 

not considered significant at this time unless entire occurrences are negatively impacted.

Alternatives 3 and 6: Cumulative impacts from implementation of Alternatives 3 and 6 are not 

considered significant. Alternatives 3 and 6 do not propose any additions to the NFTS within this plant 

community and would prohibit motorized vehicle use of all 40 miles of route located within these 

serpentine/copper/heavy metal plant communities. Therefore, implementation of Alternatives 3 and 6 may 

cumulatively impact Mielichhoferia elongata and Monardella follettii, but would not contribute to a trend 

for federally listing them as threatened or endangered. Implementation of Alternatives 3 and 6 may also 

impact Allium sanbornii var. congdonii, Allium sanbornii var. sanbornii, Chlorogalum grandiflorum and 

Perideridia bacigalupi if they occur along system routes, but those impacts are not considered significant 

in the short or long term unless entire occurrences are eliminated.

Given the above information, implementation of the action alternatives may indirectly and 

cumulatively impact Mielichhoferia elongata and Monardella follettii if they occur on the unsurveyed 

potential habitat, but would not contribute to a trend for listing them as federally listed as threatened or 

endangered over the short or long term. Implementation of the action alternatives may also indirectly and 

cumulatively impact Allium sanbornii var. congdonii, Allium sanbornii var. sanbornii, Chlorogalum 

grandiflorum, and Perideridia bacigalupi, but those impacts are not considered significant at this time 

unless entire occurrences are negatively impacted.

Older Forest Plant Communities

1. Prohibition of cross country travel

Indicator(s) used to measure effects:

• Acres where cross country travel is prohibited thereby reducing the mileage of route available for 

motorized use within older forests.
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

620 – Tahoe National Forest

No Action: Implementation of Alternative 1 would directly, indirectly, and cumulatively impact older 

forest plant communities and the sensitive species dependent on them. (There are currently no watchlist 

plants or plant communities dependent on older forests.) Alternative 1 does not prohibit cross country 

travel on 285,728 acres of TNF older forests. Under implementation of Alternative 1 as yet undiscovered 

sensitive species occurrences dependent on older forest plant communities would be at risk as new routes 

were created. It is expected that cross country use would damage at least some sensitive species 

occurrences (if they are present on TNF system lands) and it is reasonable to expect that some 

occurrences would be lost even though older forest plant communities are not considered open terrain.

There are about 285,728 acres of older forest on TNF system lands, of which 29,900 acres or about 11 

percent are currently, impacted by system and unauthorized, motorized vehicle roads/trails/areas (routes).

This acreage number was obtained using about 100 feet on either side of system and unauthorized

motorized vehicle routes that pass through vegetation mapped as CWHR 4 and above on NFS lands. The 

significance of eleven percent disturbance is unknown. There are about 2,057 miles of NFTS, state, 

county, and private routes within these plant communities.

Direct/indirect impacts to sensitive species dependent on older forest plant communities from 

implementation of Alternative 1 could be significant at least at the local, site specific level. Cross country 

use could kill/injure these older forest dependent sensitive species directly, and/or indirectly kill/injure 

them through soil changes and the introduction/spread of weeds. Cross country use would also damage 

other native vegetation in these plant communities increasing the risk of erosion and possibly damaging 

mycorrhizal networks. The significance of direct/indirect impacts is dependent on many factors including 

the amount of disturbance, the sensitive species being impacted, the number of sensitive species that 

occur in a specific location, and how many of them are damaged. The following example is provided to 

show how current use is impacting older forest dependent species.

Example - Several occurrences of Cypripedium fasciculatum are currently impacted by maintenance 

of NFTS roads. In addition, NFTS routes have provided access to Cypripedium fasciculatum occurrences 

which has contributed to poaching of these plants (plants have been dug up and removed). Over the long 

term, cross country motorized vehicles could kill significant numbers of these plants and occurrences 

could be lost. In addition, introduction of weeds could eventually eliminate the occurrences. Nonnative 

blackberries have been introduced near the roadside occurrences of this orchid in the Rock Creek area. 

This aggressive weed could eventually displace the orchids in this area.

Severe cross country impacts to older forest plant communities containing sensitive species would be 

considered significant. It is impossible to know when or where cross country motorized vehicle use would 

occur, so these disturbances are difficult to quantify. Since Alternative 1 allows cross county travel, the 

risk of significant impacts to sensitive species that may occur within unsurveyed potential habitats and 

within known occurrences is higher than the action alternatives. Reducing and/or eliminating impacts to 

sensitive species are considered effective methods of reducing cumulative impacts to them. However, flag 

and avoid is not a practical mitigation when cross country travel is allowed. Allowing unrestricted 

motorized vehicle use across the Forest greatly increases the risk of negative indirect impacts to sensitive 

species.
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

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Action alternatives: None of the action alternatives allow cross country travel within older forest 

plant communities. Therefore, direct/indirect impacts to sensitive species dependent on older forest plant 

communities from cross country travel would not occur. Refer to Table 3.06-9. Alternative 5 prohibits 

public motorized use of about 727 of the 768 miles of unauthorized routes and closed NFTS roads still 

receiving some motorized use located within older forest plant communities or about 95 percent. (About 

49 miles of the 817 miles of unauthorized routes and closed NFTS roads within older forest plant 

communities is already prohibited by existing Forest Orders.) Alternative 2 prohibits public motorized use 

of about 735 miles in older forest plant communities or about 96 percent. Alternative 6 prohibits public 

motorized use on about 736 miles or about 96 percent also. Alternative 4 prohibits use on about 752 miles 

or 98 percent and Alternative 7 prohibits motorized use on 747 miles or about 97 percent. Alternative 3 

prohibits public motorized use on all 817 miles of unauthorized routes and closed NFTS roads still 

receiving some motorized use.

2. Additions to the NFTS and Reopening ML 1 Roads

Indicator(s) used to measure effects:

• Miles of proposed additions to the NFTS within older forest plant communities. The miles of 

proposed additions that pass through older forests (CWHR 4 and above) is the indicator used to 

analyze impacts to unsurveyed older forest habitats. Table 3.06-9 displays the number of miles of 

motorized vehicle road/trail/areas in older forest plant communities by alternative.

• Sensitive species (associated with older forests) located within 100 feet of proposed additional 

NFTS motorized recreation opportunities. Surveys to date have shown that Cypripedium 

fasciculatum is located within 30 feet of several NFTS roads.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

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Table 3.06-9. Miles* of road/trail/area within older forest plant communities by alternative

Action type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

1. Cross country travel 

(miles located within older forest plant communities)

(acres located within older forest plant communities)

817

285,728

0 0 0 0 0 0

2. Additions 

to the NFTS

Miles added within 100 feet of 

older forest

N/A 33 0 16 41 32 21

3. Establishment of Motorized “Open Areas”

(acres)

N/A 0 0 0 0 0 0

4. Changes 

to the NFTS

a. Change in Class of Vehicles 

resulting from approval of mixed 

use

No Effect

b. Change in Class of Vehicles 

resulting from changes in 

maintenance levels

No Effect

c. Change in Season of Use No Effect

d. Reopening Maintenance Level 1 

Roads 

0 0 0 0.1 51 5 1

5. Amendments to the Forest Plan No Effect

Total Miles 

Total Acres

2,874

285,728

2,090

0

2,057

0

2,073

0

2,149

0

2,094

0

2,079

0

*Miles are approximate. The total mileage includes NFTS, State, County, and private roads. Alternative 1 total mileage also includes 

unauthorized routes and closed NFTS roads still receiving some motorized use.

No Action: Alternative 1 does not propose additions to the NFTS but it does not prohibit public 

motorized use of unauthorized routes and closed NFTS roads still receiving some motorized use and it 

allows cross country travel. Implementation of Alternative 1 could impact sensitive species 

directly/indirectly by continuing use of about 817 miles of unauthorized routes and closed NFTS roads 

still receiving some motorized use located within older forest plant communities. Refer to Table 3.06-9

which shows the miles of route within these plant communities by alternative. Implementation of 

Alternative 1 could also directly/ indirectly impact sensitive species through use of about 2,057 miles of 

NFTS, state, county, and private routes located within these plant communities. Direct/indirect impacts 

could be significant.

Sensitive species dependent on older forests were not found in the more recent botanical surveys

(about 95 miles of recent survey). No new weed occurrences were found in older forest plant 

communities in these surveys.

Action alternatives: Compared to Alternative 1, all action alternatives would reduce the number of 

miles of unauthorized routes and closed NFTS still receiving some motorized use designated as open for 

motorized vehicles in older forest plant communities. Of the action alternatives, implementation of 

Alternative 5 proposes the most miles of addition to the NFTS – about 41 miles. Therefore, 

implementation of Alternative 5 has the greatest risk of negative impacts to sensitive species dependent 

on older plant communities of the action alternatives. Alternatives 2 and 6 propose the addition of 33 and 

32 miles respectively to the NFTS. Alternative 7 proposes to add about 21 miles to the NFTS. Alternative 
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

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4 proposes to add about 16 miles to the NFTS. Alternative 3 does not propose any additions to the NFTS 

or propose reopening any ML 1 roads. 

About 32 miles of proposed additions to the NFTS located within older forest plant communities 

have been surveyed and no sensitive species were found. However, these surveys did not target sensitive 

fungi. Therefore, sensitive fungi may be present even in the areas that received recent botanical surveys.

Of the action alternatives, Alternative 5 carries the greatest risk to sensitive species dependent on older 

forests since at least 9 miles of proposed additions have not received current botanical surveys.

Alternative 3 carries the least risk.

3. Cumulative effects including reasonably foreseeable

Indicator(s) used to measure effects: Past/present/reasonably foreseeable future actions that could 

potentially impact older forest plant communities and the sensitive species dependent on them as well as 

the benefits from prohibiting public motorized use on unauthorized routes and closed NFTS roads are 

discussed. It is assumed that all of the action alternatives avoid long term cumulative impacts by 

implementing frequent evaluation of routes, implementing mitigations to reduce impacts to sensitive 

species, and conducting annual weed detection surveys with rapid treatment of weeds. This route 

evaluation combined with rapid mitigation of resource damage avoids significant impacts to older forest 

plant communities and the sensitive species dependent on them in the short and long term.

Past: Many acres of older forest plant communities in the Sierra Nevada have been directly removed 

or have had their functions impaired. In the Sierra Nevada, late-successional older forests of middle 

elevations (westside mixed conifer, red fir, white fir, eastside mixed conifer, and eastside pine types) at 

present constitute 7 to 30 percent of the Forest cover, depending on forest type (Sierra Nevada Ecosystem 

Project 1996). It is reasonable to expect that the native plant species dependent on older forest plant 

communities have also experienced a decline in range and population viability since pre-settlement times. 

For example, sensitive fungi are dependent on specific vegetation (hosts) and certain amounts of leaf 

litter/duff. These habitat components for fungi have been historically reduced and/or eliminated through 

the removal of vegetation and alteration of older forest plant communities. The amount of reduction is 

unknown. In addition, the underground mycelial network has been broken through the creation of 

openings such as clearcuts and roads. Therefore, it is reasonable to expect that past management activities 

have cumulatively reduced the amount of older forest within TNF watersheds that would be suitable 

habitat for: Cudonia monticola, Cypripedium fasciculatum, Cypripedium montanum, Dendrocollybia 

racemosa, and Phaeocollybia olivacea. As stated above, the amount of reduction is unknown.

Current: In this analysis, older forest is described as occurring in the red fir/upper montane forest 

and mixed-conifer forest. Other vegetation types exist that also have older trees, but mixed conifer and 

red fir are the primary types of older forest analyzed in this document. For more information about old 

forests, refer to the SNFPA (2001).

As mentioned previously, there are about 285,728 acres of older forest on TNF system lands, of 

which 29,900 acres or about 11 percent are currently, impacted by system and unauthorized, motorized 

vehicle roads/trails/areas (routes). This acreage number was obtained using about 100 feet on either side 
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

624 – Tahoe National Forest

of system and unauthorized motorized vehicle routes and closed NFTS roads still receiving some 

motorized use that pass through vegetation mapped as CWHR 4 and above on NFS lands. The 

significance of this percentage is unknown. Refer to the wildlife biological evaluation located in the 

project record for a discussion of cumulative effects to older forest dependent animal species. Current 

impacts (that contribute to cumulative effects primarily from use of system routes) to known occurrences 

of the older forest dependent sensitive plant species – Cypripedium fasciculatum are discussed below.

There are 5 occurrences of Cypripedium fasciculatum on TNF system lands. One of the 5 known 

occurrences contains only 3 plants (Lafayette Ridge occurrence) and is not impacted directly /indirectly 

by motorized vehicle use. The remaining four occurrences are indirectly impacted by motorized vehicle 

use of the NFTS. There are Cypripedium fasciculatum occurrences located within 100 feet of the 25-28 

road (50 plants directly above the road), the Rock Creek road (less than 30 plants some located directly 

adjacent to the road), the Madrone Springs road (about 20 plants located on the road cut bank), and the 

largest occurrence (about 350 plants) located at the end of a road near Old Condon Mill. (Note that the 

25-28 road is analyzed for decommissioning in the Canyon Project – FY 2008.) Indirect impacts include 

dust and increased risk of weed introduction and spread. These indirect impacts are not considered 

significant at this time. However, illegal road maintenance and poaching have killed some plants. It is 

unknown whether these illegal activities would continue. However, the existence of the system roads in 

these locations adds to the cumulative effects to these plants.

Special uses projects such as utility corridor construction and maintenance, mining operations, and 

livestock grazing are all ongoing projects that are not known to impact occurrences of Cypripedium 

fasciculatum.

Reasonably foreseeable: Over the long term, with continued disturbance, older forest plant 

communities would continue to be fragmented through implementation of reasonably foreseeable 

management actions. In general terms, motorized vehicle use of system routes creates linear disturbances. 

As mentioned previously, there are 1,258 miles of NFTS, state, county, and private routes in older forests 

on Forest lands. The impacts of linear disturbances within older forest plant communities are not fully 

studied. The fuel reduction/timber harvest activities identified in Appendix H (Reasonably Foreseeable 

Projects and Cumulative Effects) impact older forests but must retain some older forest characteristics due 

to SNFPA direction for maintenance of specific canopies and retention of larger trees. The effects of fuel 

reduction/timber harvest on mycorrhizal interactions are not fully understood. The other types of 

reasonably foreseeable projects (other than fuel reduction/timber harvest) listed in Appendix H are 

expected to have little impact on older forest plant communities.

No action: Implementation of Alternative 1 cumulatively impacts older forest plant communities. 

Older forests are not considered sparsely vegetated and the ability to drive across the terrain is somewhat 

limited. However, surveys to date have shown that motorcycles are not limited in their ability to drive 

cross country through older forest plant communities. Refer to the project files and the survey records of 

specific routes. In addition, some older forests lack a middle story which makes them more accessible to 

motorized vehicles.
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

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When the impacts of all past, current and reasonably foreseeable management actions are added to the 

possible impacts of cross country travel, use of unauthorized and system routes, there is the potential to 

significantly impact older forests and the sensitive species dependent on them over the long term (5 years 

plus). One of the biggest impacts of disturbance of any kind is the introduction and spread of weeds. 

Refer to the weed risk assessment located in the project record for more discussion of how weeds are 

introduced and spread within older forest plant communities.

Given the above information, the determination is that implementation of Alternative 1 could impact 

Cudonia monticola, Cypripedium fasciculatum, Cypripedium montanum, Dendrocollybia racemosa, and 

Phaeocollybia olivacea. Impacts to the sensitive fungi: Cudonia monticola, Dendrocollybia racemosa, 

and Phaeocollybia olivacea would not contribute to a trend for federal listing because the ESA does not 

apply to fungi. Impacts to Cypripedium fasciculatum and Cypripedium montanum could contribute to a 

trend toward federal listing over the long term primarily due to cross country travel.

Action alternatives: Compared to Alternative 1, all action alternatives would reduce the number of 

miles of unauthorized routes and closed NFTS roads designated as open for motorized vehicles in older 

forest plant communities. However, implementation of the action alternatives could cumulatively impact 

sensitive species dependent on older forest plant communities. 

Past management activities have cumulatively reduced the amount of older forest plant communities 

within TNF watersheds. Current impacts including the use of system routes, add to those cumulative 

impacts. Some proposed additions to the NFTS and some ML 1 roads proposed for reopening do not have 

current surveys and may have sensitive species present within or along them. Impacts from motorized use 

of these routes may be adding to the cumulative impacts to older forests. Some of the reasonably 

foreseeable actions listed in Appendix H (Reasonably Foreseeable Projects and Cumulative Effects) are 

located within older forest plant communities and/or would reduce the amount of large down 

wood/canopy closure/litter and duff - changing older forest characteristics for some older forest

dependent sensitive species.

As mentioned previously, older forest plant communities in the Sierra Nevada have been directly 

removed or have had their functions impaired. Given the past history of the Sierra Nevada, it is 

reasonable to expect that the plant and fungi species dependent on older forest conditions have 

experienced a significant decline in range and population viability since pre-settlement times (although 

this assumption is unproven).

Alternative 5: Implementation of Alternative 5 cumulatively impacts older forest plant communities 

and the sensitive species dependent on them. Alternative 5 proposes the most miles of additions to the 

NFTS and the reopening of the most miles of ML 1 roads of all of the action alternatives. Alternative 5 

also prohibits public motorized use of the fewest miles of route located within older forests. Therefore 

implementation of Alternative 5 has the greatest risk of negatively impacting older forest plant 

communities and the sensitive species dependent on them. The significance of possible impacts is 

dependent on many factors including the sensitive species and the amount of impact. However, as stated 

previously, it is assumed that all of the action alternatives avoid significant long term cumulative impacts 

by implementing frequent evaluation of routes, implementing mitigations to reduce impacts to 
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

626 – Tahoe National Forest

sensitive/watchlist species, and conducting weed detection surveys with rapid treatment of weeds. This 

route evaluation combined with rapid mitigation of resource damage avoids significant impacts to older 

forest plant communities and the sensitive/watchlist species dependent on them in the short and long 

term. 

Alternatives 2 and 6: Implementation of Alternatives 2 and 6 could add to the cumulative impacts to 

older forest plant communities and the sensitive species dependent on them primarily through dust and 

increased risk of weed introduction and spread. These additional cumulative impacts are not considered 

significant even when added to past, current, and reasonably foreseeable future management actions. The 

risk of negative impacts due to implementation of Alternatives 2 and 6 is less than under implementation 

of Alternatives 1 and 5.

Alternatives 4 and 7: Implementation of Alternatives 4 and 7 could add to the cumulative impacts to 

older forest plant communities and the sensitive species dependent on them primarily through dust and 

increased risk of weed introduction and spread. Those impacts are not considered significant even when 

added to past, current, and reasonably foreseeable future management actions. The risk of negative 

impacts due to implementation of Alternatives 4 and 7 is less than under implementation of Alternatives 1 

due to the prohibition of cross country travel and Alternatives 5, 2, and 6 because they propose fewer 

miles of addition to the NFTS and reopen fewer ML 1 roads. 

Alternative 3: Implementation of Alternative 3 could cumulatively add to the cumulative impacts to 

older forest plant communities and the sensitive species dependent on them primarily through use of 

system routes. However, implementation of Alternative 3 has the least number of miles of motorized 

vehicle road/trail/area available for public use within older forest plant communities and has the least risk 

of cumulative impacts to sensitive species that require older forest plant communities of all of the action 

alternatives. Alternative 3 does not propose additions to the NFTS and does not reopen ML 1 roads.

Given the above information, it is my determination that implementation of the action alternatives

could impact Cudonia monticola, Cypripedium fasciculatum, Cypripedium montanum, Dendrocollybia 

racemosa, and Phaeocollybia olivacea. Impacts to the sensitive fungi (Cudonia monticola,

Dendrocollybia racemosa, and Phaeocollybia olivacea) would not contribute to a trend for federal listing 

because the ESA does not apply to fungi. Impacts to Cypripedium fasciculatum and Cypripedium 

montanum would not contribute to a trend toward federal listing due to the assumptions that frequent 

route evaluation would occur along with implementation of mitigations to reduce impacts to 

sensitive/watchlist species, and weed detection surveys with rapid treatment of weeds.

Oak Woodland Plant Communities

1. Prohibition of cross country travel

Indicator(s) used to measure effects:

• Acres where cross country travel is prohibited thereby reducing the mileage of route available for 

motorized use within oak woodlands.

No Action: Implementation of Alternative 1 could directly, indirectly, and cumulatively impact oak 

woodland plant communities and the sensitive/watchlist species that may occur within them. Alternative 1 
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

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does not prohibit cross country travel and as yet undiscovered sensitive/watchlist species would be at risk 

as new routes were created. It is expected that cross country use would damage at least some 

sensitive/watchlist species (if they are present on Tahoe NFS lands) and it is reasonable to expect that 

some occurrences would be lost. Oak woodland plant communities are considered fairly open terrain.

There are about 13,886 acres of oak woodland on TNF system lands, with about 75 miles of NFTS

and 23 miles of unauthorized routes and closed NFTS roads still receiving some motorized use located 

within them. Alternative 1 closes one mile of unauthorized route within oak woodlands by existing Forest 

Order.

Direct impacts to sensitive/watchlist species from implementation of Alternative 1 could be 

significant at least at the local, site specific level. Cross country use could kill and/or injure 

sensitive/watchlist species and other vegetation by running over them or by indirect soil/water changes 

and the introduction and spread of weeds. The significance of direct and indirect impacts is dependent on 

many factors including the amount of disturbance, the sensitive/watchlist species being impacted, and in 

some cases, the season when the disturbance takes place. Currently there are no sensitive/watchlist 

species on the TNF list that are oak woodland plant community dependent. However, several of the 

sensitive/watchlist species on the TNF list could grow in oak woodlands.

Severe cross country impacts within oak woodland plant communities containing sensitive/watchlist 

species would be considered significant. It is impossible to know when or where cross country motorized 

vehicle use would occur, so these disturbances are difficult to quantify. Since Alternative 1 allows cross 

county travel, the risk of significant impacts to sensitive/watchlist species that may occur within potential 

habitats lacking current surveys is higher than in the action alternatives. Reducing and/or eliminating 

impacts to sensitive/watchlist species are considered effective methods of reducing cumulative impacts to 

them. However, flag and avoid is not a practical mitigation when cross country travel/unrestricted 

motorized vehicle use is allowed. 

Action alternatives: None of the action alternatives allow cross country travel. Therefore, direct 

impacts to sensitive/watchlist species within oak woodland plant communities from cross country travel 

would not occur. In addition, all of the action alternatives prohibit public motorized vehicle use of the 

about 23 miles of unauthorized routes and closed NFTS roads still receiving some motorized use located 

within oak woodland plant communities.

2. Additions to the NFTS and Reopening ML 1 Roads

Indicator(s) used to measure effects:

• Miles of proposed additions to the NFTS system located within oak woodland plant communities.

No Action: Alternative 1 does not propose additions to the NFTS. However, implementation of 

Alternative 1 could impact sensitive/watchlist species directly, indirectly, and cumulatively by continuing 

motorized vehicle use of 23 miles of route located within oak woodland plant communities. Refer to 

Table 3.06-10. Motorized vehicle use of about 75 miles of NFTS, state, county, and private routes located 

within these plant communities also adds to cumulative impacts. Direct/indirect impacts could be 
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

628 – Tahoe National Forest

significant dependent on many factors such as the species type, amount of disturbance, etc. Surveys to 

date have not detected any sensitive/watchlist species or new weed occurrences within oak woodlands.

Table 3.06-10. Miles* of road/trail/area within oak woodland plant communities by alternative

Action type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

1. Cross country travel 

(miles located within oak woodland plant 

communities)

(acres located within oak woodland plant 

communities)

23

13,886

0 0 0 0 0 0

2. Additions 

to the NFTS

Miles added within oak 

woodlands

N/A 0 0 0 0 0 0

3. Establishment of Motorized “Open Areas”

(acres)

N/A 0 0 0 0 0 0

4. Changes 

to the NFTS

a. Change in Class of Vehicles 

resulting from approval of mixed 

use

No Effect

b. Change in Class of Vehicles 

resulting from changes in 

maintenance levels

No Effect

c. Change in Season of Use No Effect

d. Reopening Maintenance Level 1 

Roads 

0 0 0 0 1 0 0

5. Amendments to the Forest Plan No Effect

Total Miles

Total Acres

98

13,886

75

0

75

0

75

0

76

0

75

0

75

0

*Miles are approximate. The total mileage includes NFTS, State, County, and private roads. Alternative 1 total mileage also includes 

unauthorized routes and closed NFTS roads still receiving some motorized use.

Action alternatives: Compared to Alternative 1, all action alternatives would reduce the number of 

miles open for motorized vehicles in oak woodland plant communities. Of the action alternatives, 

implementation of Alternative 5 proposes the reopening of about 1 mile of ML 1 road. Therefore, of the 

action alternatives, implementation of Alternative 5 has the greatest risk of negative impacts to 

sensitive/watchlist species that may occur within oak woodland plant communities. ML 1 roads lack 

current botanical surveys. Sensitive/watchlist species and/or plant communities could occur 

within/adjacent to them and could be experiencing negative impacts from motorized vehicle use.

Alternatives 2, 3, 4, 6, and 7 do not propose adding any miles to the NFTS and do not propose reopening 

any ML 1 roads.

3. Cumulative effects including reasonably foreseeable

Indicator(s) used to measure effects: Past/present/reasonably foreseeable future actions that could 

potentially impact oak woodland plant communities and the sensitive/watchlist species and/or watchlist 

plant communities that may occur within them, as well as the benefits from prohibiting public motorized 

vehicle use of unauthorized routes and closed NFTS roads are discussed. 
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

Tahoe National Forest – 629

Past: As identified previously, California’s oak woodlands have experienced extensive historic 

disturbance. No other ecosystem in the Sierra Nevada has experienced more human influence over a 

longer time period than the oak woodlands (Anderson in SNFPA 2001). The amount of oak woodland 

plant communities and their health has been reduced across the State.

Current: Motorized vehicles impact TNF oak woodlands by: introducing and spreading weeds, 

damaging native vegetation, increasing soil erosion, and fragmenting habitats. Refer to Table 3.06-10 for 

the number of miles of motorized vehicle road/trail/area proposed within oak woodlands by alternative. 

Other ongoing projects on the Forest that impact oak woodlands include: special uses projects such as 

utility corridor construction and maintenance that pass through and impact oak woodlands; minerals 

operations that remove native vegetation and recontour the landscape; and livestock grazing projects. The 

TNF does not have any sensitive/watchlist species that are entirely dependent on oak woodlands. 

However, several sensitive plant species are known to occur in oak woodlands including Clarkia biloba

ssp. Brandegeae.

Reasonably foreseeable: When the past and current impacts are added to the impacts of the 

reasonably foreseeable future actions identified in Appendix H (Reasonably Foreseeable Projects and 

Cumulative Effects), risks to oak woodlands increase. Some of the reasonably foreseeable projects 

identified in Appendix H would benefit oaks even though they are not located in oak woodlands because 

some oak tree species occur within mixed conifer plant communities. Some of the fuel reduction/timber 

harvest activities identified in Appendix H retain oaks and remove conifers from around the larger oak 

trees so they receive more light and nutrients – for example the Canyon Forest Health project. The biggest 

negative impact of disturbance of any kind within oak woodlands is the increased risk of introduction and 

spread of weeds.

No action: Implementation of Alternative 1 allows cross country use within TNF oak woodland plant

communities and carries the greatest risk of negative impacts to those plant communities. Oak woodlands 

have a high risk that weeds would be introduced and become established due to the lower elevations of 

these plant communities. Cross country travel could introduce and spread weeds. Refer to the weed risk 

assessment (located in the project record) for the effects of weed infestation. In summary, weeds can 

displace sensitive/watchlist species and other native vegetation if the weeds become established and 

spread. Weed introduction and spread within sensitive/watchlist species occurrences is considered a 

significant long term impact. Therefore, when the impacts of all past, current and reasonably foreseeable 

management actions are added together, the possible impacts of cross country travel and motorized use of 

unauthorized routes and closed NFTS roads within oak woodlands has the potential to significantly 

impact sensitive/watchlist species over the long term (5 years plus).

Action alternatives: Compared to Alternative 1, all action alternatives would reduce the number of 

miles open for motorized vehicle use in oak woodlands. Implementation of the action alternatives reduces

cumulative impacts to sensitive/watchlist species and/or native vegetation located within oak woodlands.

The significance of these impacts is unknown. It is assumed that all of the action alternatives avoid long 

term cumulative impacts by implementing: frequent evaluation of routes, mitigations designed to reduce 

impacts to sensitive/watchlist species, and conducting frequent weed detection/treatment activities. 
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

630 – Tahoe National Forest

Implementation of these activities along with rapid mitigation of resource damage avoids significant 

impacts to oak woodlands plant communities and sensitive/watchlist species in the short and long term.

Alternative 5: Compared to Alternative 1, implementation of Alternative 5 has less risk of negative 

impacts to sensitive/watchlist species within oak woodlands. Conversely, implementation of Alternative 5 

carries the highest risk of negative impacts to oak woodland plant communities of the action alternatives 

since it proposes to reopen one mile of ML 1 road. Compared to Alternative 1, Alternative 5 reduces 

cumulative impacts to oak woodland plant communities by prohibiting cross country travel.

Alternatives 2, 3, 4, 6, and 7: These action alternatives do not propose additions to the NFTS and do 

not reopen ML 1 roads in oak woodland plant communities. Therefore, implementation of these 

alternatives carries less risk of weed introduction and spread than Alternatives 1 and 5, and reduces

cumulative impacts to oak woodland plant communities when compared to Alternatives 1 and 5.

Forest edges and openings

1. Prohibition of cross country travel

Indicator(s) used to measure effects:

• Acres where cross country travel is prohibited thereby reducing the mileage of route available for 

motorized use within forest edges/openings. (Note: there is overlap between these plant 

communities and aquatic/riparian, serpentine, older forest, oak woodland and high elevation 

rocky opening plant communities. Therefore the number of miles of unauthorized routes and 

closed NFTS roads still receiving some motorized use present in forest edge and openings plant 

communities contains some of the miles of same routes shown in other plant communities and the 

totals from all plant communities do not add up to the total of about 1,698 miles.)

No Action: Implementation of Alternative 1 could directly, indirectly, and cumulatively impact the 

sensitive/watchlist species dependent on forest edges and openings. Over the long term (5 years plus) 

those impacts could be significant. Alternative 1 does not prohibit cross country travel and plant 

communities located within forest edges and openings are accessible to motorized vehicles. Under 

implementation of Alternative 1 known and as yet undiscovered sensitive/watchlist species would be at 

risk of negative impacts. It is expected that long term cross country use would injure/kill some 

sensitive/watchlist species and it is reasonable to expect that some occurrences would be lost.

There are about 630,667 acres of forest edge/openings on Tahoe NFS lands, with about 3,489 miles of 

NFTS, state, county, and private routes and 1,148 miles of unauthorized routes and closed NFTS roads 

still receiving some motorized use located within them. 

Direct impacts to sensitive/watchlist species from cross country use could be significant at least at the 

local, site specific level. The significance of direct/indirect impacts is dependent on many factors 

including the amount of disturbance, the sensitive/watchlist species being impacted, and in some cases, 

the season when the disturbance takes place. The significance of impacts is also dependent on the number 

of sensitive/watchlist species that occur in a specific location and how many of them are damaged. 

Occurrences of Clarkia biloba ssp. Brandegeae, Fritillaria eastwoodiae, Lewisia kelloggii ssp. 
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

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hutchisonii, Lilium humboldtii ssp. humboldtii, Lupinus dalesiae, and Phacelia stebbinsii are known to be 

impacted by use of system routes. Refer to the occurrence records located in the TNF files.

Severe cross country impacts within forest edge/openings containing sensitive/watchlist species 

would be considered significant. It is impossible to know when or where cross country motorized vehicle 

use would occur, so these disturbances are difficult to quantify. Since Alternative 1 allows cross county 

travel, the risk of significant impacts to sensitive/watchlist species is higher than in the action alternatives. 

Reducing and/or eliminating impacts to sensitive/watchlist species through flag and avoid methods is not 

a practical mitigation when cross country travel is allowed. Allowing unrestricted motorized vehicle use 

across the forest greatly increases the risk of negative impacts to sensitive/watchlist species.

Action alternatives: Compared to Alternative 1, all action alternatives would reduce the number of 

miles open for motorized vehicles. None of the action alternatives allow cross country travel. Therefore, 

direct/indirect impacts to sensitive/watchlist species within forest edges/openings from cross country 

travel would not occur. Refer to Table 3.06-11. Alternative 5 prohibits motorized public use on about 

1,098 miles of the 1,148 miles of unauthorized routes and closed NFTS roads still receiving some 

motorized use or about 96 percent of them. Alternatives 2 and 6 prohibit motorized public use on about 

1,116 and 1,112 miles respectively or about 97 percent of them. Alternatives 4 and 7 prohibit motorized 

public use on 1,134 and 1,130 miles or about 99 and 98 percent of them. Alternative 3 prohibits motorized 

public use on all 1,148 miles of unauthorized routes and closed NFTS roads still receiving some 

motorized use located within forest edges/openings.

Table 3.06-11. Miles of road/trail/area within forest edge/opening plant communities* by alternative

Action type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

1. Cross country travel 

(miles)

(acres)

1,148

630,667

0 0 0 0 0 0

2. Additions 

to the NFTS

Miles added within forest

edge/opening plant communities

N/A 32 0 14 50 36 18

3. Establishment of Motorized “Open Areas” 

(acres)

N/A 0 0 0 0 0 0

4. Changes 

to the NFTS

a. Change in Class of Vehicles 

resulting from approval of mixed 

use

No Effect

b. Change in Class of Vehicles 

resulting from changes in 

maintenance levels

No Effect

c. Change in Season of Use No Effect

d. Reopening Maintenance Level 1 

Roads 

0 0 0 0 72 9 1

5. Amendments to the Forest Plan No Effect

Total Miles

Total Acres

4,637

630,667

3,521

0

3,489

0

3,503

0

3,611

0

3,534

0

3,508

0

*Forest edge/opening plant communities are those that are not considered older forest, oak woodland, aquatic/riparian, high 

elevation opening/rocky area, and serpentine. Miles represent routes that pass within 100 feet of forested plant communities. Miles 

are approximate. The total mileage includes NFTS, State, County, and private roads. Alternative 1 total mileage also includes 

unauthorized routes and closed NFTS roads still receiving some motorized use.
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

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2. Additions to the NFTS and Reopening ML 1 Roads

Indicator(s) used to measure effects:

• Miles proposed for addition to the NFTS located within forest edges/openings.

No Action: Alternative 1 does not add routes to the NFTS but it does not prohibit public motorized 

vehicle use of 1,148 miles of unauthorized routes and closed NFTS roads still receiving some motorized 

use. Implementation of Alternative 1 could impact sensitive/watchlist species directly/indirectly by 

continuing use of those unauthorized routes and closed NFTS roads. Implementation of Alternative 1 

could also directly/indirectly impact sensitive/watchlist species through use of about 3,489 miles of NFTS 

located within these plant communities. Refer to the discussion under effects of cross country use under 

the No Action Alternative above. Direct/indirect impacts could be significant at least at the site specific, 

local level. 

Action alternatives: Compared to Alternative 1, all action alternatives would reduce the number of 

miles open for motorized vehicles in forest edges/openings. No sensitive/watchlist species and/or new 

weed occurrences were found in forest edges/openings during surveys for this project. However, ML 1

and temporary roads do not have current botanical surveys. Therefore, it is possible that sensitive/

watchlist species exist within/along them and they are being impacted.

Refer to Table 3.06-11 which shows the miles of proposed additions to the NFTS and miles of ML 1

roads proposed to be reopened within these plant communities by alternative. Alternative 5 proposes the 

addition of 50 miles to the NFTS. Alternatives 2 and 6 add 32 and 36 miles respectively. The risk of 

negative impacts to sensitive/watchlist species from implementing Alternatives 2 and 6 is less than 

Alternative 5. Alternatives 4 and 7 add 14 and 18 miles respectively. Therefore, the risk of negative 

impacts to sensitive/watchlist species from implementing Alternatives 4 and 7 is less than Alternatives 5, 

2 and 6. Alternative 3 does not propose additions to the NFTS within forest edges/openings. Therefore, 

implementation of Alternative 3 has the least risk of negatively impacting sensitive/watchlist species 

through motorized vehicle use.

3. Cumulative effects including reasonably foreseeable

Indicator(s) used to measure effects: Past/present/reasonably foreseeable future actions that could 

potentially impact forest edges/openings and the sensitive/watchlist species that may occur within them, 

as well as the benefits from prohibiting public motorized vehicle use of unauthorized routes and closed 

NFTS roads are discussed. 

Past: Plants that are dependent on openings and edges within forested plant communities are not 

considered habitat specific and the plant communities/habitats are not considered limited. Management 

activities have occurred on TNF system and privately owned lands for over a century. This long history of 

disturbance has contributed to the lack of an undisturbed reference for most plant species. Therefore, it is 

not possible to quantify how these past management activities have impacted sensitive plants/fungi and 

watchlist plants/plant communities. In addition, as previously mentioned past management has created 

conditions on the landscape that frequently contribute to cross country travel through the creation of skid 

trails and temporary roads. In a number of areas motorized vehicle users have removed the barriers 
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blocking the temporary road and/or have gone around the barriers. Past management activities have 

cumulatively added to the amount of forest edge/opening habitats but it is unknown if the edge and 

opening habitats created were suitable for: Androsace occidentalis var. simplex, Clarkia biloba ssp. 

Brandegeae, Erigeron petrophyllus var. sierrensis, Fritillaria eastwoodiae, Lewisia kelloggii ssp. 

hutchisonii, Lilium humboldtii ssp. humboldtii, Lupinus dalesiae, and Phacelia stebbinsii.

Current: Openings and forest edges are constantly being created naturally as trees and other 

vegetation dies, and lost when shrubs and other vegetation grow into them. In addition, forest edge/

opening plant communities located along roads/trails/areas and other highly disturbed areas such as 

landings have frequently become invaded by weeds. Most of the known weed occurrences on the TNF are 

located along or within roads/trails and landings. 

The TNF is considered well roaded. Motorized vehicle use of roads is known to increase the risk of 

weed introduction and spread into new areas, reduce native plant cover, increase erosion, reduce 

photosynthetic ability of native plants by covering vegetation with dust, change water flow patterns across 

the landscape, and compact soil. Refer to the Sensitive Plant and Fungus Biological Evaluation and the 

Noxious Weed Risk Assessment located in the project record. Examples of current impacts to known 

occurrences of sensitive/watchlist species are provided below to show how current cross country travel by 

motorized vehicles adds to cumulative impacts.

Example 1: The TNF has limited numbers of the sensitive plant Lewisia kelloggii var. hutchisonii and 

limited amounts of suitable habitat. Several occurrences are currently being directly/indirectly impacted 

by cross country motorized vehicle use and use of NFTS routes. Other occurrences are currently being 

impacted by fuel reduction/timber harvest projects – for example in the American River Wildfire 

Complex. The habitat where this plant grows frequently appears barren since this plant completes its life 

cycle in a period of weeks. Over the long term (over 5 years), continued and increased cross country 

motorized vehicle use within these occurrences would eventually kill plants through soil compaction, 

changes in hydrology, and/or direct impacts such as running over them. An example of where these 

negative impacts are occurring is within the occurrence located along and within road 302-15.

Example 2: Most of the known occurrences of Clarkia biloba ssp. Brandegeae on the TNF are 

growing next to roads where occurrences are currently being run-over by cross country motorized 

vehicles. In addition, in some areas, invasive exotic weeds have been introduced into these plant 

communities by motorized vehicles causing a degradation of the habitat for these sensitive plants. For 

example, the Clarkia biloba ssp. Brandegeae occurrence located near Mosquito Ridge road is infested 

with yellow star thistle due in part to people pulling off the road and introducing these weed seeds into 

new areas. Competition from the yellow star thistle for water and nutrients may eventually kill the 

Clarkia biloba ssp. Brandegeae occurrence. Current impacts include reduction of vigor and lack of 

reproduction of this annual plant, compaction and/or degradation of the soil within the occurrence, and/or 

changes to water movement where they are growing.

Example 3: Several species are known to be negatively impacted by road maintenance and/or weed 

infestation. Lilium humboldtii ssp. humboldtii is currently being impacted by use of NFTS and other 

roads. Impacts to known occurrences include introduction and spread of weeds and loss of the plants 
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through road maintenance. Since this is a spring flowering bulb species, impacts from dust are not 

considered significant. Examples of where weeds are competing with this plant can be found along 

Highway 49 near Coyote Street where Scotch broom has moved into the area where this lily is growing 

and crowding out the lilies. Examples of where road maintenance has eliminated these lilies occurred 

along Highway 174 near Bear River (personal observation). Lupinus dalesiae occurrences are being 

directly/indirectly impacted by maintenance of system roads in several locations for example along the 

Gold Lakes Road.

Example 4: Phacelia stebbinsii plants are being directly/indirectly impacted by motorized vehicle use 

on system and user created trails in the Pierce OHV area. Cross country travel has created wheel tracks 

that have been blocked off to protect these sensitive plants and wetlands, but users continue to go around 

the barricades. Plants have been crushed and killed prior to setting seed which has reduced reproduction 

for this annual plant.

Reasonably foreseeable: Forest edge/opening habitats are cumulatively impacted when past and 

current impacts are added to the reasonably foreseeable future actions identified in Appendix H

(Reasonably Foreseeable Projects and Cumulative Effects). The lower elevation forest edge/opening 

habitats located along system roads/trails/areas have frequently received weed seed from motorized 

vehicle use. All of the projects identified in Appendix H would disturb existing forest edge/openings 

and/or create new ones. Most of the ground disturbing projects identified in Appendix H have had 

botanical surveys to identify presence or absence of sensitive/watchlist species. Where sensitive/watchlist 

species were found, mitigations were implemented to reduce and/or eliminate impacts to them.

No action: Implementation of Alternative 1 allows cross country use within NFS forest edge/opening 

habitats and carries the greatest risk of negative impacts to those habitats. Cross country use could 

directly/indirectly impact Astragalus webberi, Calochortus clavatus var. avius, Clarkia biloba ssp. 

brandegeae, Fritillaria eastwoodiae, Lewisia kelloggii ssp. hutchisonii, Lewisia kelloggii ssp. kelloggii, 

Lupinus dalesiae, Penstemon personatus, and Phacelia stebbinsii (if they occur within the area of cross 

county use). Predicting where cross country motorized vehicle use would occur is not possible. It is likely 

that this cross country travel would damage and/or kill sensitive/watchlist species. In addition, impacts to 

known occurrences would occur. Impacts could be significant dependent on such factors as the 

sensitive/watchlist species being impacted, the number of individuals being impacted, and the severity of 

the disturbance. For example, direct impacts to an annual plant (such as Phacelia stebbinsii) that has 

already gone to seed would not be as adverse (as long as significant habitat alteration has not occurred) as 

direct impacts to an annual plant that has not set seed. If motorized vehicle use impacted a sensitive/

watchlist species to the point that it might not remain viable in an area and the loss of that species in that 

particular area would substantially influence the extinction risk of the entire species, the motorized 

vehicle use would have significant impacts to that species (Waples et al. 2007). As noted above, it is 

impossible to know when or where cross country motorized vehicle use would occur but since it would 

not be restricted in the No Action Alternative, the risk of negative impacts is higher. Since (in general 

terms) no restrictions would be in place to limit where motorized vehicle use could occur, all 

sensitive/watchlist species that can be accessed by motorized vehicles would be at increased risk. 
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

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Cumulative impacts could be significant. Over the long term, cross country motorized vehicle use could 

kill significant numbers of sensitive/watchlist species and the occurrences could be lost. In addition, 

introduction of weeds could eventually eliminate the occurrences.

Given the above information, implementation of Alternative 1 could impact Astragalus webberi,

Calochortus clavatus var. avius, Clarkia biloba ssp. brandegeae, Fritillaria eastwoodiae, Lewisia 

kelloggii ssp. hutchisonii, Lewisia kelloggii ssp. kelloggii, Lupinus dalesiae, Penstemon personatus, and 

Phacelia stebbinsii and those impacts could contribute to a trend for federal listing as threatened or 

endangered. Implementation of Alternative 1 could also impact the watchlist plants, Erigeron petrophyllus 

var. sierrensis, and Lilium humboldtii ssp. humboldtii. Impacts to watchlist plants are not considered 

significant unless entire occurrences are lost. Over the long term, cross country travel within the only 

known occurrence of Erigeron petrophyllus var. sierrensis on the TNF could cause the loss of the entire 

occurrence.

Action alternatives: As identified previously, it is assumed that all of the action alternatives avoid 

long term cumulative impacts by implementing frequent evaluation of routes, implementing mitigations 

to reduce impacts to sensitive/watchlist species, and rapid detection/treatment of weeds. This route 

evaluation combined with rapid mitigation of resource damage avoids significant impacts to forest 

edges/openings and sensitive/watchlist species in the short and long term.

Surveys of proposed additions to the NFTS identified an occurrence of Erigeron petrophyllus var. 

sierrensis growing in a serpentine plant community along and within YRN-7. Refer to that section for a 

discussion of impacts to this watchlist plant. No other sensitive/watchlist species were found in surveyed 

forest edge/rocky opening plant communities. However, temporary and ML 1 roads do not have current 

surveys. In addition, many of the dispersed camping access routes also lack current surveys. Since forest 

edge/opening plant communities have a high likelihood of having been disturbed in the more recent past, 

there is a high risk of weeds being present in those areas lacking current surveys. The list of proposed 

additions that pass through forest edges/openings is located within the project record since it is a long list 

(9 pages long). However, Table 3.06-11 displays the number of miles of proposed additions and the miles 

of ML 1 roads proposed for reopening within forest edge/opening plant communities by alternative.

Alternative 5: Of the action alternatives, implementation of Alternative 5 has the highest risk of 

indirect/cumulative impacts to sensitive/watchlist plants that may be growing in forest edge/opening plant 

communities. However, implementation of Alternative 5 has less risk of indirect/cumulative impacts to 

sensitive/watchlist species growing in forest edges/openings than Alternative 1 because it does not allow 

cross country travel. Alternative 5 proposes the addition of 50 miles to the NFTS, and reopening about 72 

miles of ML 1 roads. If sensitive/watchlist species occur within 100 feet of ML 1 or temporary roads 

proposed in Alternative 5 they would continue to be impacted until they are detected during routine 

maintenance checks. The significance of these impacts to sensitive/watchlist species would vary 

dependent on such factors as the type of species, amount of disturbance, and location of the sensitive/

watchlist species. Impacts are not considered significant over the short term (5 years or less). Over the 

long term, the risk of weeds being introduced and/or spreading from undetected weed occurrences is high.

However, it is assumed that routine evaluation of routes would occur by personnel who can identify weed 
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

636 – Tahoe National Forest

species while the infestation is small in size and easily treated. Current impacts from cross country travel 

would not occur – it is assumed that users would stay on designated routes. When impacts from 

reasonably foreseeable projects are added to implementation of Alternative 5, the risk to sensitive/

watchlist species is high primarily from weed introduction and spread.

Alternatives 2 and 6: Implementation of Alternatives 2 and 6 could cumulatively impact sensitive/

watchlist species dependent on forest edge/opening habitats but those impacts are not considered 

significant for the reasons given under Alternative 5. Alternatives 2 and 6 propose the addition of 32 and 

36 miles of route (respectively) which is less than the 50 miles proposed under Alternative 5. Alternative

2 does not propose to reopen ML 1 roads and Alternative 6 would reopen about 9 miles of ML 1 road 

which is less miles of road than the 72 miles proposed under Alternative 5. The risk of negative impacts to 

sensitive/watchlist species from implementing Alternative 6 is higher than in Alternative 2 but less than 

Alternative 5. As in Alternative 5, it is assumed that current impacts from cross country travel would not 

occur because users would stay on designated routes. However, when impacts from reasonably 

foreseeable projects are added to implementation of Alternatives 2 and 6, the risk to sensitive/watchlist 

species is high primarily from weed introduction and spread.

Alternatives 4 and 7: Implementation of Alternatives 4 and 7 adds to the cumulative impacts to 

sensitive/watchlist species in forest edges/openings. Alternatives 4 and 7 add 14 and 18 miles 

respectively. Alternative 4 does not propose to reopen any ML 1 roads and Alternative 7 proposes to open 

less than about 1 mile of ML 1 road. Current impacts from cross country travel are not expected. When 

the impacts from reasonably foreseeable projects are added to implementation of Alternatives 4 and 7, the 

risk to sensitive/watchlist species is lower than in Alternatives 5, 2 and 6.

Alternative 3: Implementation of Alternative 3 adds to the cumulative impacts of forest edge/opening 

plant communities and the sensitive/watchlist species growing in them, from the use of the NFTS.

Alternative 3 does not propose any additions to the NFTS, does not propose reopening any ML 1 roads, 

and does not allow cross country use. Implementation of Alternative 3 would prohibit public motorized 

vehicle use on all 1,148 miles of unauthorized routes and closed NFTS roads still receiving some 

motorized use. Alternative 3 has the lowest risk of weed introduction and spread which is a benefit for all 

sensitive/watchlist species.

Given all of the above information, implementation of the action alternatives could impact Astragalus 

webberi, Calochortus clavatus var. avius, Clarkia biloba ssp. brandegeae, Fritillaria eastwoodiae, 

Lewisia kelloggii ssp. hutchisonii, Lewisia kelloggii ssp. kelloggii, Lupinus dalesiae, Penstemon 

personatus, and Phacelia stebbinsii, but would not contribute to a trend for federally listing them as 

threatened or endangered. Implementation of the action alternatives could also impact the watchlist 

plants, Lilium humboldtii ssp. humboldtii and Erigeron petrophyllus var. sierrensis but those impacts are 

not expected to cause the loss of entire occurrences.
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

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High elevation openings and rocky areas

1. Prohibition of cross country travel

Indicator(s) used to measure effects:

• Acres where cross country travel is prohibited (thereby reducing the mileage of routes available 

for motorized use) within high elevation openings/rocky areas.

No Action: Implementation of Alternative 1 would directly, indirectly, and cumulatively impact the 

sensitive/watchlist species dependent on high elevation openings and rocky areas. Over the long term (5 

years plus) those impacts could be significant. Alternative 1 does not prohibit cross country travel on 

about 43,240 acres of high elevation openings and rocky areas (high elevation openings and rocky areas 

are generally considered accessible to motorized vehicles). Under implementation of Alternative 1 known 

and as yet undiscovered sensitive/watchlist species occurrences would be at risk. Over the long term,

cross country use could damage at least some sensitive/watchlist species occurrences and it is reasonable 

to expect that some occurrences would be lost.

Direct/indirect impacts to sensitive/watchlist species from cross country use could be significant at 

least at the local, site specific level. The significance of direct/indirect impacts is dependent on many 

factors including the amount of disturbance, the sensitive/watchlist species being impacted, and in some 

cases, the season when the disturbance takes place. The significance of impacts is also dependent on the 

number of sensitive species that occur in a specific location and how many of them are damaged. 

Occurrences of Erigeron miser are known to be impacted by use of NFTS and proposed additions to the 

NFTS. Severe cross country impacts within these plant communities containing sensitive/watchlist 

species would be considered significant. Soils in these plant communities are considered highly erosive

and growing conditions are considered harsh.

Action alternatives: Compared to Alternative 1, all action alternatives would reduce the number of 

miles open for motorized vehicles in these plant communities. Direct impacts to sensitive/watchlist 

species within high elevation openings/rocky areas from cross country travel would not occur under the 

action alternatives. Refer to Table 3.06-12. Alternatives 2, 5, 6, and 7 prohibit public motorized use on 

about 16 miles of the 18 miles of unauthorized routes and closed NFTS roads still receiving some 

motorized use in these plant communities or about 89 percent of them. Alternatives 3 and 4 prohibit 

public motorized use of all 18 miles of unauthorized routes and closed NFTS roads within high elevation 

opening and rocky areas and therefore provide the least risk to those plant communities.
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Table 3.06-12. Miles of proposed additions to the NFTS within high elevation opening/rocky areas by alternative

Action type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

1. Cross country travel 

(miles located within high elevation openings & 

rocky areas)

(acres located within high elevation openings & 

rocky areas)

18

43,240

0 0 0 0 0 0

2. Additions 

to the NFTS

Miles added within 100 feet of 

high elevation/ rocky opening 

areas

N/A 2 0 0 2 2 2

3. Establishment of Motorized “Open Areas”

(acres)

N/A 0 0 0 0 0 0

4. Changes 

to the NFTS

a. Change in Class of Vehicles 

resulting from approval of mixed 

use

No Effect

b. Change in Class of Vehicles 

resulting from changes in 

maintenance levels

No Effect

c. Change in Season of Use No Effect

d. Reopening Maintenance Level 1 

Roads 

0 0 0 0 0 0 0

5. Amendments to the Forest Plan No Effect

Total Miles

Total Acres

72

43,240

56

0

54

0

54

0

56

0

56

0

56

0

2. Additions to the NFTS and Reopening ML 1 Roads

Indicator(s) used to measure effects:

• Miles of proposed additions to the NFTS within high elevation openings/rocky areas.

• Sensitive/watchlist species occurrences (associated with high elevation openings/rocky areas) 

located within 100 feet of proposed additions. Erigeron miser was found within 100 feet of TKNJ4, TKN-J5 and YRS-F1 near Fordyce Creek. No weeds were found at any of these Erigeron 

miser sites.

No Action: Alternative 1 does not and an addition to the NFTS, but it also does not prohibit public 

motorized use on about 18 miles of unauthorized routes and closed NFTS roads. Implementation of 

Alternative 1 could impact sensitive/watchlist species directly/indirectly by continuing use of those 

unauthorized routes and closed NFTS roads especially TKN-J4, TKN-J5 and YRS-F1. Under 

implementation of Alternative 1, TKN-J4 and TKN-J5 would not be shortened and the Erigeron miser

located at the end of these routes would continue to be impacted. Implementation of Alternative 1 could 

also directly impact sensitive/watchlist species through use of about 72 miles of NFTS routes located 

within these plant communities. Direct and indirect impacts could be significant at least at the local level.

Action alternatives: Compared to Alternative 1, all action alternatives would reduce the number of 

miles open for motorized vehicles in high elevation openings and rocky areas. Refer to Table 3.06-12

which shows the miles of proposed additions within these plant communities by alternative. Alternatives 
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2, 5, 6 and 7 propose the addition of about 2 miles to the NFTS located within high elevation rocky 

opening plant communities or about 11 percent. Alternatives 3 and 4 do not add miles in high elevation 

openings and rocky areas and would not directly/indirectly impact sensitive/watchlist species.

Impacts to known occurrences: Erigeron miser occurrences located at the “cement slab” at the end 

of TKN-J5, within 100 feet of TKN-J4, and along Fordyce Creek (YRS-F1) are currently being 

directly/indirectly impacted by unauthorized motorized vehicle use. Observations (by the author of this 

evaluation) have shown increased cross country motorized vehicle use within this plant community type 

on the TNF (compared to ten years ago). Mitigations were developed to reduce impacts to occurrences of 

Erigeron miser along TKN-J4 and TKN-J5. Both routes have been shortened to reduce resource impacts 

including impacts to this sensitive plant. No mitigations were developed for the Erigeron miser located 

along Fordyce Creek (YRS-F1) because current impacts are from dispersed camping versus motorized 

vehicle use. Refer to Appendix A (Site Specific Road, Trail and Open Area Information).

Impacts to potential habitat: Sensitive/watchlist species occurrences would have direct motorized 

vehicle impacts reduced and/or eliminated through implementation of mitigations for them. Indirect 

impacts such as covering them in dust and increased risk of weed introduction and spread would still 

occur. However, if sensitive/watchlist species occur within 30 or 100 feet of the routes without current 

botanical surveys they would remain undetected and could continue to be directly/indirectly impacted. 

The significance of impacts to sensitive/watchlist species varies by such factors as type of species, 

amount of disturbance, and location.

3. Cumulative effects including reasonably foreseeable

Indicator(s) used to measure effects: Past/present/reasonably foreseeable future actions that could 

potentially impact high elevation openings and rocky areas and the sensitive/watchlist species that may 

occur within them, as well as the benefits from prohibiting motorized vehicle use of unauthorized routes

and closed NFTS roads are discussed. It is assumed that all of the action alternatives avoid long term 

cumulative impacts by frequently evaluating routes, implementing mitigations to reduce impacts to 

sensitive/watchlist species, and conducting early detection and treatment of weeds. Frequent route 

evaluation combined with rapid mitigation of resource damage avoids significant impacts to high 

elevation opening and rocky area plant communities and sensitive/watchlist species in the short and long 

term.

Past: These plant communities were historically grazed by livestock, timber was removed, 

roads/trails were built through them, and some of them were impacted by mining activities. Since the 

plant communities that occur at these sites have adapted to generally highly erosive and shallow soils, 

with harsh conditions and short growing seasons; those areas that were heavily disturbed may remain 

unvegetated. In addition, heavy snow years and unchecked erosion can limit plant establishment and stop 

the vegetative recovery process or push it back by several decades (Willard et al. 2007). Some of these 

high elevation openings/rocky areas have become infested with weeds such as Klamath weed. Historic 

management activities have reduced the amount of this type of plant community and/or the health of these 

types of plant communities on the TNF. These historic reductions could have negatively impacted: Arabis 
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rigidissima var. demota, Claytonia megarhiza, Erigeron miser, Eriogonum umbellatum var. torreyanum, 

Lewisia longipetala, Tauschia howellii, and Tonestus eximius. It is believed that the Asplenium

trichomanes-ramosum occurrence located on the TNF is a disjunct occurrence and probably does not 

occur anywhere else on the TNF except in the limestone caves where it is currently known to occur. 

Historic management activities probably did not impact limestone caves on the TNF.

Current: Current management activities in these plant communities are primarily recreation related.

Erigeron miser occurrences occur along and are negatively impacted by NFTS and proposed additions to 

the NFTS. Erigeron miser grows only on the TNF, in the crevices between granite rocks - a habitat type 

that is limited in distribution on the TNF. Known occurrences are being impacted by motorized vehicle 

use when users drive over granite slabs. Non-motorized recreation, primarily mountain bikes, is also 

impacting these plant communities.

Other ongoing projects on the Forest that impact these plant communities include: special uses 

projects such as utility corridor construction/maintenance that pass through and impact many different 

types of plant communities including high elevation openings and rocky areas; minerals operations that 

remove native vegetation and recontour the landscape; and livestock grazing. None of these ongoing 

projects impacts these plant communities significantly in the short term (5 years or less). However, they 

do increase the risk of weed introduction and spread especially over the long term.

Reasonably foreseeable: High elevation openings and rocky areas are cumulatively impacted when 

past and current impacts are added to the reasonably foreseeable future impacts. However, none of the 

actions identified in Appendix H (Reasonably Foreseeable Projects and Cumulative Effects) are proposed 

in high elevation openings/rocky areas.

No action: Implementation of Alternative 1 adds to the cumulative impacts to sensitive/watchlist 

species dependent on high elevation openings/rocky areas through cross country travel and use of about 

18 miles of unauthorized routes and closed NFTS roads still receiving some motorized use in these plant 

communities. Over the long term, continued and/or increased cross country motorized vehicle use within 

sensitive/watchlist occurrences could kill significant numbers of plants. Therefore, implementation of 

Alternative 1 may significantly impact Arabis rigidissima var. demota, Claytonia megarhiza, Erigeron 

miser, Eriogonum umbellatum var. torreyanum, Lewisia longipetala, Tauschia howellii, and Tonestus 

eximius significantly over the long term (5 years plus). It is believed that the Asplenium trichomanesramosum occurrence located on the TNF is a disjunct occurrence and probably does not occur anywhere

else on the TNF except in the limestone caves where it is currently known to occur. These limestone cave 

areas are inaccessible by motorized vehicles. 

Given the above information, the determination is that implementation of Alternative 1 could impact 

Arabis rigidissima var. demota, Claytonia megarhiza, Erigeron miser, Eriogonum umbellatum var. 

torreyanum, Lewisia longipetala, Tauschia howellii, and Tonestus eximius and could contribute to a trend 

for federally listing them as threatened or endangered over the long term. Implementation of Alternative 1 

would not impact Asplenium trichomanes-ramosum.

Action alternatives: Implementation of the action alternatives could cumulatively impact 

sensitive/watchlist species dependent on high elevation openings/rocky areas. Those impacts are not 
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considered significant. In the past, motorized vehicle use was not expected to occur in these habitats 

because they are generally steep and highly erosive, rock outcrops, and/or very high elevation rocky 

openings. However, current technology has increased the ability of motorized vehicles to travel in these 

kinds of habitats. When motorized vehicle use occurs near or within these plant communities, resource 

damage (loss of vegetation and erosion) can be severe. In addition, the plants dependent on these plant 

communities do not appear to compete well with other vegetation. Therefore, weed introduction and/or 

spread could kill them over the long term. These plant communities are already subject to natural erosion 

and have a short growing period. Any disturbance increases erosion and causes significant impacts to the 

soil and water components of the habitat. 

There are 16 unauthorized routes and closed NFTS roads still receiving some motorized use located 

in these plant communities. Ten (includes YRS-F1 and YRS-F1b) of the 16 routes are considered spurs 

that access dispersed camping sites. TKN-J4, TKN-J5, YRN-11, YRS-003b, YRS-G3, and YRS-G3w are 

also located in these plant communities. Surveys identified that TKN-J4, TKN-J5 and YRS-F1 have 

occurrences of Erigeron miser within 100 feet of them. Mitigations have been developed for TKN-J4 and 

TKN-J5 that reduces and/or eliminates impacts to Erigeron miser from motorized recreation. Refer to 

Appendix A (Site Specific Road, Trail and Open Area Information).

Alternatives 2, 5, 6 and 7: Cumulative impacts from implementation of Alternatives 2, 5, 6, and 7

are not considered significant. None of these alternatives allow cross country travel. All of these 

alternatives propose the addition of about 2 miles and prohibit public motorized use of about 89 percent 

of the unauthorized routes and closed NFTS roads still receiving some motorized use. Implementation of 

these alternatives carries less risk of negatively impacting sensitive/watchlist species dependent on these 

plant communities than Alternative 1. However, of the action alternatives, implementation of Alternatives 

2, 5, 6, and 7 have the highest risk of negative indirect impacts to sensitive/watchlist species dependent on 

these plant communities since they have the most miles of motorized routes. Of the action alternatives, 

implementation of Alternatives 2, 5, 6 and 7 also have the highest risk of introducing and spreading 

weeds. Alternatives 2, 5, 6 and 7 continue the indirect impacts to Erigeron miser occurrences located 

along routes TKN-J4, TKN-J5, and YRS-F1.

Alternatives 3 and 4: Implementation of Alternatives 3 or 4 adds to the cumulative impacts of high 

elevation openings and rocky areas the least. Alternatives 3 and 4 do not allow cross country use or 

propose additions to the NFTS. Alternatives 3 and 4 do not indirectly impact Erigeron miser occurrences 

located along routes TKN-J4, TKN-J5, and the YRS-F1 near Fordyce Creek. Implementation of 

Alternatives 3 and 4 still add to cumulative impacts through the use of the NFTS and the associated risk 

of weed introduction and spread. However, of all of the alternatives, Alternatives 3 and 4 provide the 

greatest benefits to high elevation/rocky opening sensitive/watchlist species and watchlist plant 

communities.

Given the above information, implementation of the action alternatives could impact Arabis 

rigidissima var. demota, Claytonia megarhiza, Erigeron miser, Eriogonum umbellatum var. torreyanum, 

Lewisia longipetala, Tauschia howellii, and Tonestus eximius, but would not contribute to a trend for 
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642 – Tahoe National Forest

federally listing them as threatened or endangered in the short or long term. Implementation of the action 

alternatives would not impact Asplenium trichomanes-ramosum in the short or long term.

Noxious Weeds

1. Prohibition of cross country travel

Indicator(s) used to measure effects:

• Acres where cross country travel is prohibited and the miles of unauthorized routes and closed 

NFTS roads that pass through noxious weeds.

No Action: Implementation of Alternative 1 carries the highest risk of introduction and spread of 

aggressive, non-native plants (weeds) since it allows motorized vehicle use on the most miles of 

unauthorized roads/trails/areas/closed NFTS roads, and allows cross country travel on most of the Forest 

(except for areas closed by the LRMP). Motorized vehicles could potentially spread weeds to all 

accessible areas. Under implementation of Alternative 1, the number of unauthorized motorized vehicle 

roads/trails/areas would increase through cross country use.

Motorized vehicle use of those routes that have weed infestations has a high risk of spreading weeds 

to new areas. Surveys to date have identified several routes that are infested with weeds. Refer to Table 

3.06-13. The routes displayed in Table 3.06-13 have the highest short and long term risk of weed spread

to new areas. Different weeds have different ecological impacts. Table 3.06-13 also provides an indication 

of the ecological impact of the type of weed that infests the route. Under implementation of Alternative 1, 

all of the routes identified in Table 3.06-13 would continue to be used and that use would spread weeds.

Action alternatives: None of the action alternatives allow cross country travel which reduces the risk 

of introduction and spread of weeds by reducing the amount of NFS lands available for motorized travel. 

Therefore, the risk of direct/indirect impacts to sensitive/watchlist species and native plant communities 

from weed introduction and/or spread is less under the action alternatives in the short and long term 

compared to the No Action Alternative. Weeds would continue to spread on the Forest, but it is believed 

the rate of spread would be slower than under the No Action Alternative primarily due to the prohibition 

of public motorized vehicle use of some unauthorized routes, closed NFTS roads and prohibiting cross 

country travel.

Table 3.06-13. Weed occurrences along proposed additions to the NFTS

Route ID Weed occurrences known to occur within 100 feet of 

road/trail/area

Ecological impact 

rating (Cal IPC)

Route 

miles

ARM-5 Large patches of cheatgrass adjacent to the trail High .8

SV-P14 Musk thistle is within about 100 feet. Moderate .4

TKN-J9 Wooly mullein and cheatgrass Cheatgrass - High

Wooly mullein - Limited

1.4

TKN-J13 Musk thistle is adjacent to the trail. Moderate 1.6

TKN-M1 Cheatgrass is located in and adjacent High 3.6

TKN-M2 Patches of cheatgrass adjacent to the north end of the trail High 3.4

TKS-M9 Small amounts of bull thistle and orchard grass adjacent. Moderate 3.0

YRM-M3 Scotch broom adjacent High .4
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Route ID Weed occurrences known to occur within 100 feet of 

road/trail/area

Ecological impact 

rating (Cal IPC)

Route 

miles

YRM-M4 Scotch broom and cheatgrass High .4

YRN-008 Scotch broom High .3

YRN-509 Scotch/Spanish broom and cheatgrass High .5

YRN-M3b Klamath weed Moderate 2.4

YRS-SF6 Bull thistle and cheatgrass Moderate 1.4

35-4-P (Cal Ida) Cheatgrass and tumble mustard adjacent High .5

2. Additions to the NFTS and Reopening ML 1 Roads

Indicator(s) used to measure effects:

• Miles of proposed additions to the NFTS system with weed occurrences with 100 feet.

• Sensitive/watchlist species and/or watchlist plant communities located within 100 feet of 

proposed additions that also have weed occurrences within 100 feet of the route.

• Miles of ML 1 roads proposed to be reopened

No Action: Alternative 1 does not propose additions to the NFTS, but it does not prohibit public 

motorized vehicle use of unauthorized routes or ML 1 roads. Therefore, implementation of Alternative 1 

has a high risk of negatively impacting native plant communities and sensitive/watchlist species through 

the introduction and/or spread of weeds. Refer to the discussion under effects of cross country use under 

the No Action Alternative above. Direct/indirect impacts could be significant if weed infestations displace 

native plant communities.

Action alternatives: Compared to Alternative 1, all action alternatives would reduce the number of 

miles open for public motorized vehicle use. This would reduce the risk of weed introduction/spread. 

None of the action alternatives allow cross country travel which also reduces the risk of introduction of 

weeds into new areas and the spread of weeds from one place to another. Therefore, the risk of direct/

indirect impacts to native plant communities and/or sensitive/watchlist species from weed 

introduction/spread is less under the action alternatives in the long term. Refer to the Weed Risk 

Assessment located in the project record.

Surveys to date have located weed occurrences within 100 feet of routes: ARM-5, SV-P14, TKN-J9, 

TKN-J13, TKN-M1, TKN-M2, TKS-M9, YRM-M3, YRM-M4, YRN-008, YRN-509, YRN-M3b, YRSSF6, and 35-4_P of the Cal Ida network (about 20 miles of route). Those action alternatives that propose 

the addition of these routes to the NFTS have a high risk of introducing/spreading weeds in the short and 

long term. The weed risk is reduced primarily through preventative measures that focus on training of 

maintenance crews in weed identification and rapid treatment of newly established weed occurrences. The 

weed risk is also reduced through ongoing treatment of known weed occurrences. There are no cost 

effective methods known that could be used to check all vehicles for weeds and/or wash all vehicles 

before they enter NFS lands.

Motorized vehicle use of routes with weeds and rare species/plant communities have a high risk of 

negatively impacting sensitive/watchlist species and/or watchlist plant communities. TKN-M2 has an
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occurrence of Ivesia sericoleuca that has cheatgrass within 100 feet of it. Motorized vehicle use of TKNM2 increases the risk of weed introduction/spread into this sensitive species occurrence. Cheatgrass 

would compete for water and nutrients, taking those resources away from the sensitive plants. Over time, 

sensitive plants would be weakened and/or killed. Aspen plant communities were found along TKN-M2, 

and SV-P14. Motorized vehicle use of TKN-M2 and SV-P14 increases the risk of weeds being introduced 

and spreading within these aspen plant communities. The significance of impacts to the aspen from weed 

infestation is dependent on a number of factors including the type of weed.

Alternative 5: Of the action alternatives, Alternative 5 proposes the addition of the most miles of 

route known to have weed occurrences (all 20 miles, see Table 3.06-13) and proposes to reopen the most 

miles of ML 1 roads (about 93 miles) that do not have current weed surveys. Alternative 5 proposes the 

addition of TKN-M2 and SV-P14 also (routes known to have rare plants/plant communities and weeds).

Therefore, of the action alternatives, Alternative 5 has the highest risk of weed introduction and/or spread 

and the greatest risk of negatively impacting native plant communities and/or sensitive/watchlist species. 

Alternative 2: Alternative 2 proposes the addition of about 19 miles of route known to have weed 

occurrences, including the addition of TKN-M2 and SV-P14, but does not propose to reopen any ML 1

roads. Therefore, Alternative 2 has a high risk of introducing weeds to new areas from motorized vehicle 

use of routes known to have weeds. Alternative 2 could also spread weeds from weed sites that may occur 

along unauthorized routes that do not have current surveys. However, the risk of weed spread from 

undetected weed occurrences is much lower in Alternative 2 than in Alternative 5 since most proposed 

addition miles have been surveyed.

Alternatives 6 and 7: Alternative 6 proposes the addition of about 17 miles and Alternative 7 

proposes the addition of about 15 miles of route known to have weed occurrences. Alternatives 6 and 7 

both propose the addition of SV-P14. However, unlike Alternative 6, Alternative 7 does not propose the 

addition of TKN-M2. Alternative 6 reopens about 11 miles of ML 1 roads and Alternative 7 reopens about 

1 mile. Therefore, Alternatives 6 and 7 have less risk of introducing weeds to new areas from motorized 

vehicle use of routes known to have weeds than Alternatives 2 and 5. However, Alternatives 6 and 7 have 

a higher risk of spreading weeds from weed sites that may occur along ML 1 roads than Alternative 2 but 

not as much risk as under Alternative 5.

Alternative 4: Alternative 4 proposes the addition of about 12 miles of route known to have weed 

occurrences and proposes the addition of SV-P14. Alternative 4 proposes to reopen only .1 mile of ML 1

roads. Therefore, Alternative 4 has less risk of spreading weeds along routes known to have weeds than 

Alternatives 5, 2, 6, and 7.

Alternative 3: Alternative 3 does not propose the addition of any route known to have weed 

occurrences, does not propose the addition of TKN-M2 or SV-P14, and does not propose to reopen any 

ML 1 roads.

3. Cumulative effects including reasonably foreseeable

Indicator(s) used to measure effects: Past/present/reasonably foreseeable future actions that could 

potentially impact TNF system lands and the sensitive/watchlist species that may occur within them, as 
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

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well as the benefits from prohibiting motor vehicle use on unauthorized routes and closed NFTS roads are 

discussed. It is assumed that all of the action alternatives avoid long term cumulative impacts from weed 

introduction/spread by frequently evaluating routes and conducting early detection and treatment of 

weeds. Frequent route evaluation to detect weeds combined with rapid treatment of those weeds avoids 

significant impacts to native plant communities and sensitive/watchlist species in the short and long term.

Past: Most of the TNF is considered relatively weed free. This relatively weed free state may indicate 

that a source of weed seed was not available when TNF native plant communities were disturbed in the 

last century. This is unknown but appears to be a reasonable assumption based on literature that 

documents the progression of various weed species across California and the nation. It is also possible 

that weeds have persisted at low levels in some areas for decades before spreading rapidly when favorable 

conditions developed (Shepperd et al 2006). Many of the weeds found in California forests today were 

introduced intentionally or unintentionally by European settlers beginning in the 18th century (Bossard et 

al 2000). 

The lack of weed infestation in previously disturbed areas may also indicate less access onto the TNF 

by motorized vehicles. It is widely recognized that motorized vehicle use has increased over the last 

decade. It is also widely recognized that motorized use helps to spread weeds from place to place both by 

creating habitat along routes and by carrying seed/weed plant parts on vehicles. However weeds were 

introduced, it is known that they are spreading across California. Jepson (1925) listed 292 non-native 

(weed) plant species in California. By the end of the 20th century the estimate for non-native plant species 

in California has risen to 1,045 (Randall and others 1998 in Shepperd et al 2006).

Current: In general terms, most weed occurrences on the TNF are located along State/County/

Federal/NFS roads. An exception to this is the large infestation of musk thistle located in the Boca Hill 

area on the Truckee RD which is located along the Truckee River, in older plantations, and along roads 

and trails. Ongoing management actions such as utility corridor maintenance, mining operation, use of 

NFTS roads/trails, and livestock grazing continue to spread weeds from place to place across the Forest. 

As noted in other sections of this document, there are weed infestations competing with sensitive species 

for soil, water and nutrients in several locations. Sensitive species occurrences with known weed 

infestations (and/or weed occurrences within 100 feet) include occurrences of Clarkia biloba ssp. 

Brandegeae (yellow star thistle), Cypripedium fasciculatum (Himalayan blackberry), Erigeron miser

(Klamath weed) and Ivesia sericoleuca (cheatgrass). Use of road/trails has been identified as a 

contributing source of weeds in all of these known rare plant occurrences except the Klamath weed in the 

Erigeron miser occurrence. Weeds do not occur within all occurrences of sensitive/watchlist plants, but 

where they do the rare plant occurrence is at risk of being lost over the long term. Efforts have been made 

to reduce/eliminate the yellow star thistle in known Clarkia biloba ssp. Brandegeae occurrences along 

Mosquito Ridge road.

Ongoing actions that create bare soil conditions and/or reduce native vegetation and/or soil cover all 

increase the risk that weeds will become established if weed seed is introduced. Utility corridor 

maintenance, mining operations, use of NFTS roads/trails, and livestock grazing are all ongoing actions 

that create bare soil conditions and reduce native vegetation and/or soil cover.
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646 – Tahoe National Forest

Reasonably foreseeable: Implementation of those projects identified in Appendix H (Reasonably 

Foreseeable Projects and Cumulative Effects) may introduce weed seed and/or weed plant parts into new 

areas. Equipment that operates off roads while doing contracted work for the TNF must wash that 

equipment if it is coming from a weed infested area. This requirement and requiring the use of certified 

weed free plant materials for erosion control (when needed) both reduce the risk of weed introduction 

from reasonably foreseeable management actions. However, all of the projects listed in Appendix H 

involve travel on NFTS roads and could introduce weed seed into new areas from their vehicles. Ground 

disturbance favors weed spread if the weeds are already in or near the area being disturbed. Therefore, it 

is reasonable to expect that implementation of the reasonably foreseeable actions would introduce weeds 

into new areas and/or spread weeds from existing weed infestations over the long term.

No action: Implementation of Alternative 1 adds to the cumulative risk of weeds being introduced 

into new areas and spreading from existing weed sites. As identified in the Weed Risk Assessment for this 

project (refer to the project record) implementation of Alternative 1 has a high risk of introducing weeds 

into new areas and spreading weeds from areas that are already infested with weeds. The risk to native 

plant communities and/or sensitive/watchlist species from implementation of Alternative 1 is significant 

when added to past/current/reasonably foreseeable actions. Alternative 1 allows cross country use, does 

not prohibit motorized vehicle use of unauthorized routes, and does not prohibit use of closed NFTS

roads. Therefore, it has the greatest risk of negative impacts to native plant communities and the 

sensitive/watchlist species, of any of the alternatives. 

Action alternatives: Motorized vehicle use provides a continuous source of weed seed introduction 

and also provides disturbed areas within and adjacent to the motorized vehicle roads/trails/areas. Refer to 

the Weed Risk Assessment (in the project record) and the discussion under the No Action Alternative for 

more information. None of the action alternatives allow cross country use. Therefore, all of the action 

alternatives have less risk of introducing weeds into new areas than Alternative 1. In addition, some 

reduction of weed risk is expected from ongoing treatment of known weed occurrences. The risk of weed 

introduction and spread includes discussion of risk from using routes known to be infested and risk from

use of routes that may be infested (routes without current surveys).

Alternative 5: Of the action alternatives, implementation of Alternative 5 has the greatest risk of 

weed introduction and spread and therefore the greatest risk of negative impacts to native plant 

communities and/or sensitive/watchlist species. Alternative 5 has the greatest weed risk of the action 

alternatives because it proposes the addition of the most miles of route known to have weed occurrences 

(all 20 miles) and proposes to reopen the most miles of ML 1 roads (about 93 miles) that do not have 

current weed surveys. Alternative 5 also proposes the addition of TKN-M2 and SV-P14 (routes known to 

have rare plants/plant communities and weeds). When current and reasonably foreseeable actions are 

added to the high risk that implementing Alternative 5 would introduce and spread weeds, the cumulative 

impacts could be significant. However, the assumption of frequent review of routes and rapid treatment of 

weeds reduces the significance of Alternative 5’s contribution to cumulative impacts.
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

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Since Alternative 5 does not allow cross country travel, it has less risk of spreading weeds into native 

plant communities and/or sensitive/watchlist species occurrences over the long term than implementation 

of Alternative 1.

Alternative 2: Alternative 2 proposes the addition of about 19 miles of route known to have weed 

occurrences, proposes the addition of TKN-M2 and SV-P14, but does not propose to reopen any ML 1

roads. Therefore, Alternative 2 has a high risk of introducing weeds to new areas from motorized vehicle 

use of routes known to have weeds. In addition, Alternative 2 adds shoreline access on dry soils in the 

Prosser/Boca/Stampede Reservoir areas and the Greenhorn area. Reservoir shoreline areas are known to 

have weed occurrences when the water level is low. For example, Canada thistle is known to occur along 

the low water line of French Meadows Reservoir and musk thistle and other weeds are known to occur 

along the Boca Reservoir low water line. Unvegetated areas provide sites where weeds can readily 

become established without competition from native vegetation. Prosser/Boca/Stampede Reservoir areas 

and the Greenhorn area have been surveyed and weeds are not currently present. In addition, weeds would 

have a harder time becoming established along the reservoirs when the water levels are high. When weed 

occurrences are covered with water, many of the weed seeds are killed. However, some of the weed seed 

floats to new areas. When water levels remain low for a period of time, weeds can become established 

and any motorized vehicle use in the areas where the weeds are located would spread the weeds to new 

areas.

The risk of weed spread from undetected weed occurrences is much lower in Alternative 2 than in 

Alternatives 1 and 5. When current and reasonably foreseeable actions are added to the risk that 

implementing Alternative 2 would introduce and spread weeds, there would be additions to cumulative 

impacts. However, since most of the risk is tied to use of routes with current surveys/known infestations, 

the risk is reduced by implementation of ongoing weed treatments. In addition, as mentioned above, the 

assumption of frequent review of routes and rapid treatment of newly established weeds reduces the 

significance of any action alternative’s contribution to cumulative impacts.

Alternatives 6 and 7: Alternative 6 proposes the addition of about 17 miles and Alternative 7 

proposes the addition of about 15 miles of route known to have weed occurrences. Alternatives 6 and 7 

both propose the addition of SV-P14. However, Alternative 7 does not propose the addition of TKN-M2.

Therefore the risk of spreading weeds from known infestations is high. Alternatives 6 and 7 do not 

propose “Open Areas.” Therefore, Alternatives 6 and 7 have less risk of introducing weeds to new areas 

from motorized vehicle use of routes known to have weeds than Alternatives 2 and 5.

Alternative 6 reopens about 11 miles of ML 1 roads and Alternative 7 reopens about 1 mile. 

Alternative 6 has a higher risk of spreading weeds from weed infestations that may occur along these ML 

1 roads than Alternative 7. Alternatives 6 and 7 have a higher risk of spreading weeds from weed sites that 

may occur along ML 1 roads than Alternatives 2 but not as much risk as under Alternative 5.

The above contributions to cumulative impacts are not considered significant due to the assumption 

of frequent review of routes with rapid treatment of newly established weeds.

Alternative 4: Alternative 4 proposes the addition of about 12 miles of route known to have weed 

occurrences and proposes the addition of SV-P14. Alternative 4 proposes to reopen only .1 mile of ML 1
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648 – Tahoe National Forest

roads and does not propose “Open Areas.” Therefore, Alternative 4 has less risk of spreading weeds along 

routes known to have weeds than Alternatives 5, 2, 6, and 7. Alternative 4 contributions to cumulative 

impacts are not considered significant due to the assumption of frequent review of routes with rapid 

treatment of newly established weeds.

Alternative 3: Alternative 3 does not propose the addition of any route known to have weed 

occurrences, does not propose the addition of TKN-M2 or SV-P14, and does not propose to reopen any 

ML 1 roads. Therefore, Alternative 3 has the lowest weed risk of any of the alternatives and is the most 

beneficial to native plant communities and sensitive/watchlist species.

Native Plant Habitat Fragmentation

1. Prohibition of cross country travel

Indicator used to measure effects:

• Acres where cross country travel is prohibited (thereby reducing the mileage of routes available 

for motorized use within inventoried roadless areas (IRAs).

No action: Alternative 1 does not prohibit cross country motorized vehicle use of 98,304 acres of 

Inventoried Roadless Areas (IRAs). Under implementation of Alternative 1, 58 miles of unauthorized 

routes and closed NFTS roads still receiving some motorized use located within IRAs would be available 

for motorized vehicle use and accessible areas within those IRAs would be available for cross country 

travel. As discussed above, this increases the risk of weed introduction and spread within these areas –

increasing the risk of negative impacts to native plants and sensitive/watchlist species. These negative 

impacts include reductions in native plant biodiversity and fragmentation of the native plant communities.

Impacts could be significant over the long term.

Action alternatives: None of the action alternatives allow cross country travel within IRAs. 

Therefore there is less long term risk to native plant diversity from fragmentation of large blocks of native 

plant communities by weeds under implementation of the action alternatives (compared to the No Action 

Alternative). Of the action alternatives, Alternatives 2 and 5 prohibit public motorized use on the fewest 

miles of unauthorized routes and closed NFTS roads within IRAs and have the highest long term risk to 

native plant communities from fragmentation of large blocks of native plant communities via weeds. 

Alternatives 2 and 5 would prohibit public motorized use on about 4 miles of unauthorized routes and 

closed NFTS roads within these areas or about 33 percent. Alternative 7 would prohibit public motorized 

use on about 6 miles or about 46 percent. Alternative 6 would prohibit public motorized use on about 9

miles or about 69 percent. Alternatives 3 and 4 would prohibit public motorized use on all 13 miles of 

unauthorized routes and closed NFTS roads located within IRAs. 

2. Additions to the NFTS and Reopening ML 1 Roads

Indicator used to measure effects:

• Miles proposed for addition to the NFTS that are located within IRAs.

No action: Alternative 1 does not prohibit public motorized use of the 58 miles of unauthorized routes

and closed NFTS roads located in IRAs. It also allows cross country travel. Alternative 1 has the highest 
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Tahoe National Forest – 649

long term risk to native plant communities from fragmentation of large blocks of native plant 

communities, of all the alternatives. 

Action alternatives: Compared to Alternative 1, all of the action alternatives reduce the number of 

miles open for motorized vehicles in IRAs. Of the action alternatives, Alternatives 2 and 5 propose the 

addition of the most miles of unauthorized routes located in IRAs – about 8 and 10 miles respectively.

Therefore, Alternatives 2 and 5 have the greatest long term risk of negatively impacting native plant and 

plant community diversity (from fragmentation of large blocks of native plant communities via weed 

infestation). Refer to Table 3.06-14. Alternative 7 adds about 6 miles and Alternative 6 adds about 4 

miles. Alternatives 3 and 4 do not add miles within IRAs.

Table 3.06-14. Total miles of roads/trails/areas in inventoried roadless areas by alternative

Action type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

1. Cross country travel 

(miles located within IRAs)

(acres located within IRAs)

58

98,304

0 0 0 0 0 0

2. Additions 

to the NFTS

Miles added within inventoried 

roadless areas 

N/A 8 0 0 10 4 6

3. Establishment of Motorized “Open Areas”

(acres)

N/A 0 0 0 0 0 0

4. Changes 

to the NFTS

a. Change in Class of Vehicles 

resulting from approval of mixed 

use

No Effect

b. Change in Class of Vehicles 

resulting from changes in 

maintenance levels

No Effect

c. Change in Season of Use No Effect

d. Reopening Maintenance Level 1 

Roads 

N/A 0 0 0 2 0 0

5. Amendments to the Forest Plan No Effect

Total Miles

Total Acres

207

98,304

157

0

0

0

0

0

161

0

153

0

155

0

3. Cumulative effects including reasonably foreseeable

Indicator(s) used to measure effects: Past/present/reasonably foreseeable future actions that could 

potentially impact IRAs, as well as the benefits from prohibiting public motorized use of unauthorized 

routes and closed NFTS roads are discussed. As stated previously, it is assumed that all of the action 

alternatives avoid long term cumulative impacts by frequently evaluating routes, implementing 

mitigations to reduce impacts to sensitive/watchlist species and/or watchlist plant communities, and 

conducting early detection and treatment of weeds. Frequent route evaluation to detect weeds combined 

with rapid treatment of those weeds avoids significant impacts to native plants and plant communities 

from weed infestation.

Since IRAs have not been surveyed, possible impacts to native plant biodiversity from fragmentation 

of large blocks of native plant communities are analyzed. It is recognized that sensitive/watchlist species 
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650 – Tahoe National Forest

and/or watchlist plant communities add to native plant diversity and are considered important components 

of the native plant communities where they are located.

Past: Past actions that have impacted native plant communities in TNF IRAs include all of the past 

actions identified under the different plant communities in this report. IRAs were identified in the late 

1970’s during the Roadless Area Review and Evaluation (RARE I and RARE II). The character and 

amount of roads, private land, and motorized trails varies greatly by roadless area. Refer to Section 3.09.

However, during the SNEP analysis, the East and West Yuba IRAs were identified as having some of the 

best remaining/largest concentrations of old growth forest in the Sierra Nevada.

Current: Current management activities that occur within TNF IRAs include use of NFTS 

roads/trails, activities on private land that are adjacent to NFS lands, livestock grazing and minerals 

operations. The amount of use of NFTS roads/trails, the types of private land activities, the amount and 

location of livestock grazing, and the minerals operations also vary by IRA. For example, the following 

unauthorized routes occur in the West Yuba IRA: YRN-M3b, YRN-M3a, YRN-7, and YRN-M2. All of 

these routes except YRN-7 were pioneered by miners to access mining claims. The East Yuba IRA also 

has active mining operations. YRN-001, YRN-M1, YRN-11, YRN 5a and 5c, YRN-9, YRN-007, and 

YRN-4 are all unauthorized routes that exist within the East Yuba IRA. Of these routes, YRN-M1, YRN007, and YRN-4 were pioneered by miners. YRN-11, YRN 5a and 5c, YRN-9 and probably YRN-001 

were pioneered by users. Routes used by miners to access their mining claims will remain available for 

their use regardless of the alternative selected. Refer to Section 3.09 for more information about current 

management activities within each IRA.

Reasonably foreseeable: Implementation of those projects identified in Appendix H (Reasonably 

Foreseeable Projects and Cumulative Effects) would not impact IRAs. None of those projects are located 

within IRAs.

No action: Implementing Alternative 1 has a greater risk of negative impacts to native plant diversity 

and a greater risk of negative impacts to native plant communities (and therefore the sensitive/watchlist 

species dependent on them) located within IRAs than the action alternatives. Alternative 1 has a higher 

risk of these negative impacts to plant diversity and connectivity primarily due to allowing cross country 

travel and allowing motorized use on unauthorized routes and closed NFTS roads within IRAs.

Motorized vehicle disturbance within IRAs can reduce native plant biodiversity. Loss of native plant 

biodiversity is dependent on the intensity of motorized vehicle use, but even a single vehicle pass can 

destroy or disrupt many types of plant communities. Plants with shallow root systems may be especially 

vulnerable (Wilshire 1983, Lacey et al. 1997). This loss of native vegetation increases the risk of soil loss 

due to wind and water erosion. Soil loss increases the decomposition of organic matter, weakens soil 

aggregate stability and can result in the formation of inorganic surface crusts. Inorganic surface crusts 

increase water runoff, inhibit germination and emergence of seedlings, and reduce water penetration into 

the soil. Natural soil stabilizers such as organic (lichen, fungal and algal) soil crusts are highly vulnerable 

to cross country motorized vehicle use. All of these impacts contribute to native plant community 

degradation and fragmentation.
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Motorized vehicle use can fragment native plant communities and habitat for some sensitive/watchlist 

species. Those sensitive/watchlist plants with specific pollination and other habitat requirements are the 

most vulnerable to fragmentation impacts. For example, Cypripedium fasciculatum requires mycorrhizal 

connections underground and specific pollinators and is associated with older forests. Many of the TNF 

IRAs are considered older forest. During the SNEP analysis the East/West Yuba IRAs were identified as 

important older forest areas that provide connectivity across the crest of the Sierra Nevada. The East/West 

Yuba IRAs were also found to be important because they are located in a part of the Sierra Nevada that 

has less human presence. Cross country travel within these IRAs (and the others) would fragment the 

landscape and reduce ecological function within the older forest plant communities.

Motorized vehicle use, especially cross country use, is frequently identified as the cause of habitat 

fragmentation. Cross country motorized vehicle use has been shown to reduce perennial and annual plant 

cover, reduce plant density, and overall above-ground vegetative biomass (Hall 1989). In general terms, 

the degree of plant loss depends on the intensity of motorized vehicle use.

The density of NFTS motorized vehicle routes within the various IRAs is described in Section 3.09 

(IRAs and Special Areas). Under Alternative 1, cross country use in IRAs could create high road/trail 

density over the long term with negative cumulative impacts to native plant communities. Several areas 

on the TNF have a high density of motorized vehicle roads/trails/areas – however none of the watersheds 

within IRAs are considered high risk watersheds. Refer to Section 3.02 (Soil and Watershed Resources).

The IRAs on the TNF are considered relatively free of motorized vehicle routes and are assumed to 

provide quality habitat for native plants/fungi and plant communities. Over the long term severe cross 

country travel would reduce and/or eliminate habitat for some native plants/fungi.

Large blocks of unfragmented land play an important role in providing habitat for threatened, 

endangered, proposed (TEP), and sensitive plant species (USDA FS 2000). It is expected that TNF IRAs 

provide important biological strongholds for native plant species and communities just as they do across 

the nation. Native plant communities and sensitive/watchlist occurrences within TNF IRAs are less likely 

to be exposed to disruption by human activities such as collection, trampling, and other disturbance. 

Cross country travel increases the risk of collection, trampling and other disturbances to native 

plants/plant communities. This is especially true in the East/West Yuba IRAs. Within the Sierra Nevada, 

the East/West Yuba IRAs have been identified as having less human presence than any other old growth 

forests in the range. This lower level of human disruption increases the probability that the East/West 

IRAs are important references for understanding the natural composition and dynamics of native plant 

communities. Cross country travel within these IRAs increases the probability that native plant 

community composition and ecological function would be negatively impacted.

TNF IRAs are currently less likely to experience problems with nonnative invasive species (weeds) 

and are more likely to be able to maintain intact native plant communities. Native plants/plant 

communities are at increased risk of adverse cumulative effects from increased population growth and 

associated land uses, land conversions, and nonnative species invasions throughout the Sierra Nevada. 

Therefore, the value of relatively unfragmented blocks of land such as IRAs is likely to increase as native 

plant communities are degraded. Implementation of the No Action Alternative increases the risk of native 
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

652 – Tahoe National Forest

plant community loss and degradation. Native plant community loss and degradation from the invasion 

and/or encroachment of non-native plant species are increasing within the Sierra Nevada and 

implementation of the No Action Alternative could increase the rate of loss.

Action alternatives: All of the action alternatives reduce impacts to native plants/plant communities 

by reducing the number of unauthorized routes closed NFTS roads designated motorized vehicle use

within IRAs and prohibiting cross country travel. The action alternatives that propose the addition of the 

most miles to the NFTS within IRAs have the greatest risk of negatively impacting native plant 

communities. The risk to native plants/plant communities is closely tied to the high risk of introducing 

and spreading weeds and generally increasing human presence in areas of large intact native plant 

communities (IRAs).

Alternative 5: Compared to the No Action Alternative, Alternative 5 reduces overall impacts to 

native plants/plant communities by reducing the number of unauthorized routes and closed NFTS roads 

still receiving some motorized use available to motorized vehicles within IRAs and prohibiting cross 

country travel. Of the action alternatives, implementation of Alternative 5 has the greatest risk of negative 

impacts to native plants/plant communities because it proposes the addition of the most miles of

unauthorized routes located in IRAs (about 10 miles). These proposed additions are located primarily in 

the East/West Yuba IRAs; about 3 miles of unauthorized route within the East Yuba IRA, about 4 miles 

within the West Yuba IRA, about 1 mile in Castle Peak and about 1 mile in Grouse Lakes. In addition, 

Alternative 5 proposes to reopen about 2 miles of ML 1 within the West Yuba IRA. Therefore, of the 

action alternatives, implementation of Alternative 5 has the greatest risk of negatively impacting native 

plants/plant communities within the East/West Yuba IRAs. Refer to the discussion under the No Action 

Alternative. Over the long term these additions to cumulative impacts could be significant if native plant 

community composition and ecological function are severely impacted. Much is unknown regarding the 

amount of intact older forest plant community that is needed to maintain species composition and 

ecological function within the various types in the Sierra Nevada. However, as mentioned above, the 

East/West Yuba IRA areas have been identified as unique and important old forest areas (SNEP).

Alternatives 2 and 7: Compared to the No Action Alternative, Alternatives 2 and 7 reduces overall 

impacts to native plants/plant communities by reducing the number of unauthorized routes and closed 

NFTS roads available to motorized vehicles within IRAs and prohibiting cross country travel. 

Implementation of Alternatives 2 and 7 could also negatively impact native plants/plant communities 

within IRAs because they propose the addition of about 8 and 6 (respectively) miles of unauthorized 

routes in IRAs. These proposed additions are also located primarily in the East/West Yuba IRAs.

Alternative 2 proposes about 2 miles of unauthorized routes within the East Yuba IRA, about 4 miles 

within the West Yuba IRA, 1 mile within Castle Peak and about 1 mile within Grouse Lakes. Alternative 7

proposes about 1 mile of unauthorized route within the East Yuba IRA, about 3 miles within the West 

Yuba IRA, about 1 mile in Castle Peak, and about 1 mile in Grouse Lakes. Alternatives 2 and 7 do not 

propose to reopen any ML 1 roads with in the IRAs. Therefore, the risk of negatively impacting native 

plants/plant communities within the East/West Yuba IRAs is not as high as under Alternative 5. However 

the risk is higher in Alternative 2 than in Alternative 7. Over the long term Alternatives 2 and 7 additions 
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

Tahoe National Forest – 653

to cumulative impacts could change native plant community composition and ecological function within 

IRAs. As discussed above, the significance of these possible impacts are unknown at this time.

Alternative 6: Compared to the No Action Alternative, Alternative 6 reduces overall impacts to 

native plants/plant communities by reducing the number of unauthorized routes and closed NFTS roads 

available to motorized vehicles within IRAs and prohibiting cross country travel. Implementation of 

Alternative 6 could also negatively impact native plants/plant communities within IRAs because it 

proposes the addition of about 4 miles of unauthorized routes in IRAs. These proposed additions are 

located in the East Yuba (2 miles), Castle Peak (1 mile) and the Grouse Lakes IRAs (1 mile). Alternative 6 

does not reopen any ML 1 roads with in the IRAs. Implementation of Alternative 6 has less risk of 

negatively impacting native plants/plant communities within the East Yuba IRA than Alternatives 2, 5, 

and 7 and would not add to the cumulative impacts to the West Yuba IRA. The risk of negative impacts to 

native plants/plant communities within the Castle Peak and Grouse Lakes IRAs is about the same in 

Alternative 6 as it is in Alternatives 2, 5, and 7. The significance of these possible impacts is unknown.

Alternatives 3 and 4: Compared to the No Action Alternative, Alternatives 3 and 4 reduces overall 

impacts to native plants/plant communities by reducing the number of unauthorized routes and closed 

NFTS roads available to motorized vehicles within IRAs and prohibiting cross country travel. 

Implementation of Alternatives 3 and 4 have the least risk of negative impacts to native plants/plant 

communities within IRAs. Alternatives 3 and 4 do not propose additions to the NFTS or propose 

reopening ML 1 roads within IRAs. Implementation of Alternatives 3 and 4 would benefit 

sensitive/watchlist species (if they occur there)/native plants/plant communities by reducing the risk of 

weed introduction and spread by motorized vehicles. The value of large blocks of land such as IRAs in 

conserving sensitive/watchlist species and/or watchlist plant communities is likely to increase as native 

plant communities are lost and/or degraded throughout the Sierra Nevada region through development, 

climatic change, and weed infestation.

Summary of Effects Analysis across All Alternatives

Table 3.06-15 summarizes the effects analysis for botanical resources by ranking each alternative 

regarding how well it provides for each of the indicators. This summary is not meant to convey that the 

indicators are equal in importance. The following rankings were used: A score of 7 indicates the 

alternative has the least impact for native plants/plant communities to the indicator. A score of 1 indicates 

the alternative has the most impact for native plants/plant communities related to the indicator. 
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Chapter 3: Affected Environment and Environmental Consequences – 3.06. Plant Communities

654 – Tahoe National Forest

Table 3.06-15. Comparison of Effects to Plants/Plant Communities

Indicator Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Acres where cross country travel is prohibited 

thereby reducing the mileage of route available for 

motorized use within 100 feet of riparian vegetation

1 3 7 6 2 4 5

Number of perennial and intermittent water 

crossings 

1 3 7 6 2 4 5

Aquatic/riparian dependent sensitive/watchlist 

species and/or watchlist plant communities within

0-100 feet of roads

1 3 7 6 2 4 5

Acres where cross country travel is prohibited 

thereby reducing the mileage of route available for 

motorized use that pass through serpentine 

(ultramafic) soils

1 3 7 5 2 6 4

Serpentine dependent sensitive/watchlist species 

within 0-100 feet of route

1 3 7 5 2 6 4

Acres where cross country travel is prohibited 

thereby reducing the mileage of route available for 

motorized use within older forest plant communities

1 3 7 6 2 4 5

Acres where cross country travel is prohibited 

thereby reducing the mileage of route available for 

motorized use within oak woodland plant 

communities

1 3 7 6 2 4 5

Acres where cross country travel is prohibited 

thereby reducing the mileage of route available for 

motorized use within forest edges/openings

1 3 7 6 2 4 5

Acres where cross country travel is prohibited 

thereby reducing the mileage of route available for 

motorized use within high elevation openings and 

rocky areas

1 3 7 6 2 4 5

High elevation opening dependent sensitive/

watchlist species located 0-100 feet of route

1 3 7 6 2 4 5

Sensitive/watchlist species and/or watchlist plant 

communities located within 0-100 feet of routes with

weed occurrences within 0-100 feet of the route

1 3 7 6 2 4 5

Weed infestations within 0-100 feet of route 1 3 7 6 2 4 5

Acres where cross country travel is prohibited 

thereby reducing the mileage of route available for 

motorized use within IRAs

1 3 7 6 2 5 4

Average 1 3 7 5.8 2 4.4 4.8
Chapter 3.07 

Recreation and 

Visual Resources 

Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Tahoe National Forest – 655

3.07. Recreation and Visual Resources _____________________

Recreation

Introduction

Nearly all Tahoe National Forest (TNF) visitors use roads and trails that make up the National Forest 

Transportation System (NFTS) to reach their destination. Changing the NFTS alters the diversity of 

motorized and non-motorized opportunities on the Forest. Visitors may be participating in motorized 

recreation, or using motor vehicles to access trailheads, facilities, destinations, or geographic areas used 

for non-motorized recreational activities. This section of the EIS examines how recreation opportunities 

would be affected by the Proposed Action and alternatives and how alternatives are consistent with 

direction established in the Tahoe National Forest Land and Resource Management Plan (LRMP) as 

amended in 2007, the Sierra Nevada Forest Plan Amendment, and the Travel Management (TM) Rule.

Analysis Framework: Statute, Regulation, Forest Plan,

and Other Direction

Regulatory direction relevant and specific to the each of the alternatives as it affects recreation resources 

includes:

National Forest Management Act (NFMA)

The NFMA sets forth requirements for development of Forest Plans. The Tahoe National Forest LRMP

includes standards and guidelines for management of recreation including use of motor vehicles.

Sierra Nevada Forest Plan Amendment (SNFPA)

The SNFPA established the direction to prohibit motor vehicle travel off of designated routes, trails, and 

limited off-highway vehicle (OHV) use areas. Unless otherwise restricted by current forest plans or other 

specific area standards and guidelines or forest orders, cross country travel by over-snow vehicles would 

continue.

Travel Management Rule, Subpart B (36 CFR 212.50-57)

(Criteria that incorporated E.O. 11644 and E.O. 11989). 

1. The responsible official shall consider the effects of designated roads, trails and areas on the 

provision of recreational opportunities, access needs, and conflicts among uses of National 

Forest System lands. 36 CFR 212.55 (a)

2. The responsible official shall consider effects on the following, with the objective of minimizing:

conflicts between motor vehicle use and existing or proposed recreational uses of National 

Forest System lands or neighboring federal lands; conflicts among different classes of motor 

vehicle uses of National Forest System lands or neighboring federal lands; and the compatibility 

of motor vehicle uses with existing conditions in populated areas, taking into account sound, 

emissions, and other factors. 36 CFR 212.55 (b).
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Chapter 3: Affected Environment and Environmental Consequences – 3.07. Recreation and Visual Resources

656 – Tahoe National Forest

Tahoe National Forest LRMP

The LRMP provides goals for recreation management and requires a broad range of developed and 

dispersed recreation opportunities in balance with existing and future demand. For management purposes,

combinations of activities, settings, and probable experience opportunities have been arranged along a 

spectrum, or continuum; this continuum is called the Recreation Opportunity Spectrum (ROS). The ROS 

is divided into six classes: primitive, semi-primitive non-motorized, semi-primitive motorized, roaded 

natural, rural and urban. Each class is defined in terms of its combination of activity, setting, and 

experience opportunities (ROS Users Guide USDA Forest Service, 1982). The intent is to use the ROS 

and its associated settings to provide recreation input into LRMPs which in turn may be incorporated into 

LRMP management prescriptions or used in project level planning beyond the programmatic planning 

used to develop the LRMP. For the purposes of travel management actions, “off-highway vehicles” is 

applied to public motor vehicle use (highway-legal and non-highway-legal). How the ROS applies to the 

LRMP depends on how (or if) it was integrated into the management prescriptions and associated 

standards and guidelines in the Forest LRMP. On the Tahoe National Forest, the ROS is integrated into 

management prescriptions and associated standards and guidelines in the LRMP to guide decisions and 

resource management activities. 

The following Tahoe National Forest LRMP standards and guidelines are relevant to travel 

management:

• Wheeled Vehicles and OHV Motorized Use - Prohibit wheeled vehicle travel off of designated 

routes, trails, and limited off highway vehicle (OHV) use areas. Unless otherwise restricted by 

current forest plans or other specific area standards and guidelines, cross country travel by oversnow vehicles would continue.

• OHV Motorized Use - The final determination of designated routes will be made by a trail 

management plan to be completed within one year after the Forest Plan is approved.

 Consider the following factors when addressing identified conflicts between non-motorized 

trail uses and motorized trail users (OHV): (1) Feasibility and capability of area to accept OHV 

use (minimal conflict with other resources or users), (2) Separation of the users is preferable, 

offering both types of users a satisfying recreational experience, (3) Historic use of the trail 

facility or area, (4) Safety of the users, (5) Protection of resources and trail improvements, (6) 

Cooperate with the California Department of Parks and Recreation to implement the Statewide 

Off Highway Motor Vehicle Recreational Trails Plan.

• OHV - Trail Development - Favor trail development over indiscriminate cross country use. 

Consider the following factors when developing trails; (1) Type of user, (2) Protection of the 

resource, (3) Safe access to point of interest or experience, (4) Enforcement and manageability, (5) 

Protection of private land integrity, and (6) Monitoring and evaluation capabilities.

In addition to the standards and guidelines listed above, each management area is assigned a ROS 

class or range of ROS classes to guide decisions and resource management activities. The Forest ROS 

map displays the ROS class assigned to Forest lands in the LRMP. This map was used to determine if 
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Chapter 3: Affected Environment and Environmental Consequences – 3.07. Recreation and Visual Resources

Tahoe National Forest – 657

proposed additions to the NFTS, establishing “Open Areas,” and reopening of Maintenance Level 1 roads 

would meet the ROS class allocated to the management area. See the LRMP for standards and guidelines 

specific to each management area (USDA Forest Service, 2007, as amended).

Effects Analysis Methodology

Impacts Relevant to Recreation Include:

• The compatibility of proposed changes to the NFTS with LRMP recreation and OHV management 

prescriptions and ROS.

• The impact of proposed changes to the NFTS on non-motorized (i.e., quiet) recreation (dust, noise, 

use conflicts).

• The amount and diversity of motorized recreation opportunity by alternative.

• The amount of motorized access to dispersed recreation by alternative.

• The impact of proposed changes to the NFTS on neighboring private and federal lands and 

wilderness areas (dust, noise, use conflicts).

Assumptions Specific to Recreation Analysis:

• The prohibition of cross country travel is not a change to ROS (semi-primitive motorized for 

example); it is simply a prohibition within that ROS “zone” to travel off of designated routes. 

• The change from an open to cross country travel condition to a cross country travel prohibited 

condition will reduce the availability of acreage for both motorized recreation as well as motorized 

access to dispersed recreation activities.

• The change from an open to cross country travel condition to a cross country travel prohibited 

condition will increase the availability of acreage for non-motorized recreation as well as nonmotorized access to dispersed recreation activities. 

• Proposed additions to the NFTS will have a beneficial effect on motorized recreation opportunities 

by providing a variety of trail riding experiences and increasing the amount of developed 

motorized recreation opportunities (loops, connectors). 

• Proposed changes and additions to the NFTS will have a beneficial effect on the amount of 

motorized access to dispersed recreation opportunities.

• The Forest’s national visitor use monitoring (NVUM) report provides the best available 

information for both motorized and non-motorized recreation activities described in this analysis. 

• Overall changes in the NFTS that require non-significant plan amendment(s) will result in 

corresponding changes in the net semi-primitive non-motorized ROS class acres available on the 

Forest.

• The area of influence (dust, noise) of motorized use on populated areas or “quiet recreation”

opportunities is 1⁄2 mile from associated boundaries (e.g. wilderness, research natural area (RNA), 

property line, urban limit line).
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Chapter 3: Affected Environment and Environmental Consequences – 3.07. Recreation and Visual Resources

658 – Tahoe National Forest

• There has never been any use analysis of unauthorized routes and no data exists (traffic counts, 

etc). As a result it would be highly speculative to make assumptions of use levels on the 

unauthorized routes.

Data Sources:

• TNF LRMP for distribution of ROS classes as well as the ROS GIS data layer.

• The Forest’s National Visitor Use Monitoring (NVUM) report for most popular non-motorized and 

motorized recreation activities.

• Recreation Facility Analysis for the Forest’s recreation program niche.

• Recreation, law enforcement, and other resource staff observations.

Recreation Measurement Indicators

Measurement indicators are intended to address how each alternative as the sum total of its proposed 

actions conforms to the LRMP, addresses significant issues identified in scoping, and implements Subpart 

B of the TM Rule including: whether the motorized recreation opportunity has the potential to conflict 

with other recreation opportunities, specifically non-motorized opportunities; the proximity of motor 

vehicle use to populated areas or neighboring private and federal lands and wilderness areas; the quality 

of the motorized recreation experience; and the quality of motorized access to dispersed areas for both 

motorized and non-motorized uses. The indicators also respond to the amount of motorized access 

available on the unit. Conflicts with other resources (including air quality) are examined in other resource 

sections. Public safety is addressed in the transportation section. 

Measurement indicators were used for analyzing: the prohibition of cross country travel, the addition 

of unauthorized roads or trails to the NFTS; the establishment of “Open Areas”; the changes to the NFTS 

by vehicle class, season of use, and reopening Maintenance Level 1 (ML 1) roads; and amendments to the 

Forest Plan. Mileage available for each class of vehicle is useful in analyzing the ability of Forest users to 

not only travel around the Forest and enjoy motorized recreation opportunities; but also to access nonmotorized recreation opportunities such as trailheads and dispersed recreation sites for activities such as 

hunting, fishing and camping, which the forest has determined are important based on both NVUM data 

and public scoping for this project. Mileage for motorized recreation is an indicator of the number and 

types of experiences available for motorcycles, all-terrain vehicles (ATVs), and four-wheel drive vehicles 

(4WDs) in each alternative. The changes to motorized mileages can be used to interpret the level of 

change in opportunities for motorized and non-motorized users. The details of the proposed seasonal 

closure relate to both the months that motorized recreation will not be allowed to use designated roads, 

trails or areas and, conversely, the time of year that conflicts between motorized and non-motorized uses 

will be minimized. Also, the effect on non-motorized recreation activities that are accessed by native 

surface roads is considered. The number of acres located 1⁄2 mile away from roads, trails and boundaries is

used to analyze the opportunity for non-motorized and “quiet” recreation on the Forest. The tables listed 

under each measurement indicator use mileage, acreage, and percentage to quantify the recreation 

opportunities for the effects analysis and are referred to throughout the analysis.
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Measurement Indicator 1: Consistency with LRMP

Description: This measurement indicator looks at the impact of proposed changes to the NFTS. It uses 

the Tahoe National Forest LRMP in regard to the Recreation Opportunity Spectrum (ROS) and season of 

use.

Amendments to the LRMP: The number of required plan amendments by alternative in regard to 

both ROS and changes to the season of use is displayed in Table 3.07-1. No ROS plan amendments would 

be needed for any alternatives because all routes proposed for addition to the NFTS comply with the ROS 

class in the associated management area. No proposed route additions in the action alternatives would be 

located in primitive or semi-primitive non-motorized ROS classes. All proposed route additions would be 

located in semi-primitive motorized, roaded natural or rural ROS classes. The number of ROS acres in 

each class would remain the same in each alternative. However Alternatives 2, 5, and 6 would require a 

plan amendment because of a change in the season of use of Management Area 84 (Humbug Sailor) 

related to the lifting of the deer winter range seasonal restrictions (see Tables 3.07-1 and 6, and 

Measurement Indicator 3: Motorized recreation opportunity for more information).

ROS: The number of ROS acres are shown in each class by alternative in Table 3.07-2.

Table 3.07-1. Amendments to the Tahoe National Forest Land Resource Management Plan in regard to ROS, 

and Season of Use by alternative

Amendments to the Tahoe NF LRMP

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

ROS Amendments 0 0 0 0 0 0 0

Change in Season of Use Amendments 0 1 0 0 1 1 0

Table 3.07-2. ROS acres in each class for all alternatives

ROS Class All Alternatives - Acreage Percent of total Forest acres

Primitive 33,000 4%

Semi-Primitive Non-Motorized 48,975 6%

Semi-Primitive Motorized 89,994 11%

Roaded Natural/Rural a,b 664,122 79%

Total 836,041 100%

a Acres and percentage for both Roaded Natural and Rural ROS were combined into a single category.

b No Urban ROS designations have been made on the TNF.

Measurement Indicator 2: Non-motorized recreation opportunity 

Description: This measurement indicator looks at the impact of proposed changes to the NFTS on nonmotorized recreation (dust, noise, use conflicts). It also addresses the “quiet recreation” issue.

Method: The number of acres within 1⁄2 mile of an area where motorized use is allowed (designated 

roads, trails and areas in the NFTS in miles that would result under each alternative). This method was 

determined through a literature review of sound studies and reports (Martin, et al. 2005, Ouren, et al. 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

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660 – Tahoe National Forest

2007, and Turina, et al. 2006.) Areas where motorized use is allowed (proposed or designated roads, trails 

and areas) were buffered by a distance of 1⁄2 mile. Areas outside of this buffer would be considered 

available for quiet recreation and non-motorized activities without the potential for use conflicts with 

motorized vehicles. Table 3.07-3 displays the number of acres within the 1⁄2 mile buffer or the acres 

affected by motorized use.
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Table 3.07-3. Acreage within 1⁄2 mile of routes proposed for public use under each alternative as a measurement indicator of acreage affected by 

motorized use where quiet recreation and non-motorized activities may have potential use conflicts with motorized vehicles

Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5 Alternative 6 Alternative 7

Acres and % of 

Total Forest 

Acreage

Acres % Acres % Acres % Acres % Acres % Acres %

Route Additions only 38,869a 4.6a 2,840 0.3 0 0 801 0.1 3,083 0.4 1,658 0.2 2,553 0.3

Reopening ML 1 roads 0 0 0 0 0 0 0 0 3,626 0.4 97 0.0 90 0.0

All motorized routes 

traveling through the 

Forest b

733,316a 87.7 697,281 83.4 694,447 83.1 695,242 83.2 701,062 83.9 696,193 83.3 697,078 83.4

Percent of Forest more 

than 1⁄2 mile from any 

public motorized use

12.3 16.6 16.9 16.8 16.1 16.7 16.6

a Alternative 1 proposes no unauthorized route additions, however cross country motorized travel would continue. Attempting to quantify where cross country motorized travel occurs is 

speculative since it is impossible to predict exactly where, when, or how cross country motorized use would occur. For consistency in comparing alternatives, the inventoried 

unauthorized OHV routes were used to determine the area potentially affected by cross country motorized use. The inventoried unauthorized routes are not proposed as additions 

under Alternative 1, but were used to display the minimum acreage affected by cross country motorized travel. 

b Analysis of “All motorized routes traveling through the Forest” for Alternative 1 included the inventoried unauthorized OHV routes, existing NFTS, adjacent national forest roads, and 

state, county, and private roads. Analysis of “All motorized routes traveling through the Forest” for the remaining alternatives included proposed route and area additions, existing 

NFTS, adjacent national forest roads, and state, county, and private roads.

Totals may include slight errors due to rounding.
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Chapter 3: Affected Environment and Environmental Consequences – 3.07. Recreation and Visual Resources

662 – Tahoe National Forest

Measurement Indicator 3: Motorized recreation opportunity

Description: This measurement indicator looks at the impacts of proposed additions and changes to the 

NFTS to motorized recreation opportunities by alternative. 

Roads: The number of miles available by vehicle class and the season of use are shown in Table 3.07-

4. Table 3.07-5 shows road mileage by change of vehicle class resulting from a change in the maintenance 

level (ML) or mixed use. Table 3.07-6 shows the change in miles due to a change in the season of use on 

the existing NFTS.

Trails: The number of miles available by vehicle class and season of use is shown in Table 3.07-7.

Quality of Trail Experience: The number of miles by vehicle class and degree of difficulty is shown 

in Table 3.07-8.

Areas: The number of acres in “Open Areas” by vehicle class and season of use is shown in Table 

3.07-9.

Table 3.07-4. NFTS road mileage open to the public by alternative (class of vehicle and season of use)

Class of 

Vehicle

Season of Use Additional NFTS motorized opportunities (in miles)

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Roads Added 

to the NFTS 

Open to All 

Vehicles

Apr 1 to Dec. 31 0.0 0.2 0.0 0.0 0.0 5.5 0.0

May 1 to Dec 31 0.0 0.7 0.0 3.5 4.7 7.5 0.0

May 1 to Nov 1 0.0 0.2 0.0 0.2 0.3 0.0 0.0

May 1 to Sep 15 0.0 0.0 0.0 0.0 0.0 0.0 0.0

All Year 0.0 3.7 0.0 0.0 0.0 0.0 0.0

Subtotal Additions to NFTS 0.0 5.0 0.0 3.7 5.0 13.1 0.0

ML 1 Roads 

Reopened to 

All Vehicles

Apr 1 to Dec. 31 0.0 0.0 0.0 0.0 0.3 2.2 0.0

May 1 to Dec 31 0.0 0.0 0.0 0.0 70.3 0.6 0.0

May 1 to Nov 1 0.0 0.0 0.0 0.0 8.7 0.0 0.0

All Year 0.0 0.0 0.0 0.0 0.0 0.0 0.9

Subtotal ML 1 Reopened 0.0 0.0 0.0 0.0 79.3 2.7 0.9

Total Mileage – proposed route 

additions and closed NFTS roads 

proposed as open

0.0 5.0 0.0 3.7 84.3 15.8 0.9

Total Motorized Mileage in each 

Alternativea 2,067.6 2,072.6 2,067.6 2,071.3 2,152.0 2,083.4 2,068.5

a Total Motorized Mileage in each alternative includes proposed additions to the NFTS, ML 1 reopenings, and NFTS operational 

maintenance levels (ML) 2-5.

Totals may include slight errors due to rounding.
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Table 3.07-5. NFTS road mileage open to the public forestwide – total mileage of proposed mixed use by 

alternative (class of vehicle and season of use). Mixed use would occur on existing NFTS roads. Existing 

NFTS roads where mixed use is proposed or currently allowed would be available for use by all vehicle 

classes listed in Table 3.07-4

Class of Vehicle Season of Use NFTS Mileage Proposed for Mixed Use

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Change in Class 

of Vehicles 

resulting from 

approval of 

mixed use a

Apr 1 to Sep 15 0.0 5.2 0.0 0.0 5.2 0.0 0.0

Apr 1 to Dec 1 0.0 54.2 0.0 0.0 54.2 4.4 0.0

May 1 to Dec 31 0.0 45.2 0.0 0.0 45.2 1.2 0.0

May 1 to Nov 1 0.0 4.1 0.0 0.0 4.1 2.9 0.0

Open to All Vehicles Sep 22 to 

Nov 4, Highway legal vehicles 

only Nov 5 to Sep 21

0.0 0.0 0.0 0.0 0.0 74.2 0.0

Open to Highway legal vehicles 

only May 1 to Sep 21, All 

Vehicles Sep 22 to Nov 4,

Highway legal vehicles only Nov 

5 to Dec 31

0.0 0.0 0.0 0.0 0.0 43.3 0.0

All Year 0.0 132.8 0.0 0.0 132.8 4.8 0.0

Subtotal 0.0 241.5 0.0 0.0 241.5 130.8 0.0

Change in Class 

of Vehicles 

resulting from 

changes in 

maintenance 

levels

Apr 1 to Dec 1 0.0 2.5 0.0 0.0 2.5 39.7 0.0

Apr 1 to Sep 15 0.0 0.0 0.0 0.0 0.0 5.2 0.0

May 1 to Nov 1 0.0 1.4 0.0 0.0 1.4 1.4 0.0

May 1 to Dec 31 0.0 75.9 0.0 3.4 153.3 75.6 0.0

All Year 0.0 77.4 0.0 0.0 0.0 0.0 3.4

Subtotal 0.0 157.2 0.0 3.4 157.2 121.9 3.4

Total Motorized Mileage available for mixed use 

in Alternative b 0.0 398.7 0.0 3.4 398.7 252.7 3.4

a Mileage proposed for mixed use where such use is currently prohibited

b Determined by adding the proposed mixed use mileage and mileage currently available for mixed use (Operational ML 2 on 

existing NFTS). 

Totals may include slight errors due to rounding.

Table 3.07-6. Miles of NFTS routes with a proposed change in the season of use by alternative

Action type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Change in Season of Use a 0.0 10.5 0.0 1,312.1 1,396.7 1,369.5 0.0

a Change may be positive or negative, depending upon alternative
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Chapter 3: Affected Environment and Environmental Consequences – 3.07. Recreation and Visual Resources

664 – Tahoe National Forest

Table 3.07-7. NFTS Trail mileages open to the public forestwide by alternative 

Action type Class of 

Vehicle

Season of Use Mileage Proposed to be Added to NFTS

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Motorize Trail 

Additions to 

the NFTS

Trails Open 

to HighClearance 

4WD

Apr 1 to Dec 31 0.0 0.0 0.0 0.0 1.1 10.6 0.0

May 1 to Dec 31 0.0 8.4 0.0 5.5 43.5 12.0 7.5

May 1 to Sep 15 0.0 0.0 0.0 0.0 0.1 0.0 0.0

All Year 0.0 15.9 0.0 0.0 0.0 0.0 9.4

Trails Open 

to ATVs & 

Motorcycles

Apr 1 to Dec 31 0.0 0.0 0.0 0.0 0.0 3.8 0.0

May 1 to Dec 31 0.0 0.9 0.0 2.9 4.7 0.9 0.0

All Year 0.0 3.4 0.0 0.0 0.0 0.0 3.4

Trails Open 

to 

Motorcycles

Apr 1 to Dec 31 0.0 0.0 0.0 1.1 12.3 11.1 0.0

May 1 to Dec 31 0.0 9.9 0.0 13.0 13.7 9.9 6.5

All Year 0.0 16.0 0.0 0.0 0.0 0.0 9.8

Subtotal Additions to NFTS 0.0 54.5 0.0 22.5 75.4 48.3 36.6

Reopening 

ML 1 Roads 

to motorized

trail use

Trails Open 

to ATVs & 

Motorcycles

Apr 1 to Dec 31 0.0 0.0 0.0 0.0 0.0 8.5 0.0

May 1 to Dec 31 0.0 0.0 0.0 0.0 13.9 0.0 0.0

Trails Open 

to 

Motorcycles

Apr 1 to Dec 31 0.0 0.0 0.0 0.1 0.1 0.1 0.0

All Year 0.0 0.0 0.0 0.0 0.0 0.0 0.1

Subtotal ML 1 Reopened 0.0 0.0 0.0 0.1 14.0 8.6 0.1

Total Additions to the NFTS 0.0 54.5 0.0 22.6 89.4 56.9 36.7

Total Trail Mileage Available 328.2 382.7 328.2 350.9 417.6 385.1 365.0

Totals may include slight errors due to rounding.
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Chapter 3: Affected Environment and Environmental Consequences – 3.07. Recreation and Visual Resources

Tahoe National Forest – 665

Table 3.07-8. NFTS Trail mileages open for public use forestwide by alternative by degree of difficulty

Class of 

Vehicle

Action type Degree of 

Difficulty

Mileage Proposed to be Added to NFTS

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Trails Open to 

Highclearance 

4WD

Trail Additions 

to the NFTS

Easy 0.0 8.1 0.0 2.8 19.0 5.5 5.0

Moderate 13.3 2.3 22.2 14.4 9.6

Difficult 1.5 0.3 2.1 1.5 1.3

Ext. Difficult 1.3 0.1 1.3 1.2 0.9

High-clearance 4WD Additions to NFTS 0.0 24.3 0.0 5.6 44.7 22.5 16.9

Trails Open to 

ATVs & 

Motorcycles

Trail Additions 

to the NFTS

Easy 0.0 4.4 0.0 2.9 4.8 4.8 3.4

Moderate 0.0 0.0 0.0 0.0 0.0

Difficult 0.0 0.0 0.0 0.0 0.0

Ext. Difficult 0.0 0.0 0.0 0.0 0.0

Reopening 

ML 1 Roads 

to motorized

trail use

Easy 0.0 0.0 0.0 0.0 13.9 8.5 0.0

Moderate 0.0 0.0

Difficult 0.0 0.0

Ext. Difficult 0.0 0.0

ATV and Motorcycle Additions to NFTS 0.0 4.4 0.0 2.9 18.7 13.3 3.4

Trails Open to 

Motorcycles

Trail Additions 

to the NFTS

Easy 0.0 4.8 0.0 1.1 4.8 3.8 1.0

Moderate 18.8 13.0 18.8 17.1 13.0

Difficult 0.0 0.0 0.0 0.0 0.0

Ext. Difficult 2.4 0.0 2.4 0.0 2.4

Reopening 

ML1 Roads to 

motorized trail 

use

Easy 0.0 0.0 0.0 0.0 0.0 0.0 0.0

Moderate 0.1 0.1 0.1 0.1

Difficult 0.0 0.0 0.0 0.0

Ext. Difficult 0.0 0.0 0.0 0.0

Motorcycle Additions to NFTS 0.0 25.9 0.0 14.2 26.1 21.0 16.5

Total Additions to the NFTS 0.0 54.6 0.0 22.7 89.5 56.8 36.8

Totals may include slight errors due to rounding.

Table 3.07-9. “Open Area” acreage forestwide by alternative by vehicle class

Vehicle Class Season of 

Use

Acreage Proposed to be Added to NFTS

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Total Open to All 

Vehicles

All year 754,066 2,649 0 0 0 0 0

Total Open to 

Highway-legal 

Use

All year 754,066 2,649 0 0 0 0 0

May 1 –

December 31

0 0 0 0 0 244 0

Total Acreage in 

Alternative

754,066a 2,649 0 0 0 244 0

a “Open Area” acreage under Alternative 1 is open to both highway-legal and non-highway-legal use.
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Chapter 3: Affected Environment and Environmental Consequences – 3.07. Recreation and Visual Resources

666 – Tahoe National Forest

Measurement Indicator 4:

Type of motorized access to dispersed recreation

Description: This measurement indicator looks at the impact of proposed changes to the NFTS to 

motorized access to dispersed recreation opportunities by alternative. 

Quality of Road/Trail/Dispersed Recreation Experience: The number of proposed facilities (proposed 

road and trail additions and reopened ML 1 roads) that provide access to dispersed recreation sites were 

used for this indicator and is used to determine the number of dispersed sites accessed. One site per 

proposed road addition or reopened ML 1 road was used as a proxy. However, in some instances multiple 

sites are accessed via a single route addition. 

The Tahoe NF has identified proposed road and trail additions that provide access to dispersed 

camping sites in each alternative. The number of dispersed recreation sites shown in Table 3.07-10 below 

represents the minimum number of dispersed recreation sites potentially accessed in each alternative. 

Table 3.07-10. Number of dispersed recreation sites accessed by routes proposed for addition to the NFTS, 

or ML 1 roads reopened to motorized use under each alternative

Action type Class of Vehicle Number of Dispersed Sites Accessed

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Additions to the 

NFTS

Roads Open to All Vehicles N/Aa 114 0 85 112 346 0

Trails Open to High-Clearance 4WD N/Aa 62 0 18 64 80 23

Trails Open to ATVs & Motorcycles N/Aa 2 0 1 2 2 2

Trails Open to Motorcycles N/Aa 4 0 3 5 4 2

Reopening ML 1

roads to 

motorized use

as roads or 

trails

Roads Open to All Vehicles N/Aa 0 0 0 3 3 1

Trails Open to ATVs & Motorcycles N/Aa 0 0 0 1 1 0

Trails Open to Motorcycles N/Aa 0 0 0 1 1 1

Total Sites Accessed in Alternative N/Aa 182 0 107 188 437 29

a Under Alternative 1, access to dispersed recreation sites would continue. The number of sites accessed is difficult to determine. 

With continued cross country motorized travel under Alternative 1, access to dispersed recreation sites would be available on lands 

open to cross country motorized travel. See Table 3.07-7 for “Open Area” acreage available under Alternative 1.

Measurement Indicator 5: Impact of proposed changes to the NFTS on 

neighboring private and federal lands (dust, noise, use conflicts)

Description: This measurement indicator looks at the impact of proposed changes to the NFTS on 

neighboring private and federal lands (dust, noise, use conflicts) by alternative. 

Method: Table 3.07-11 shows the number of miles of routes proposed for addition to the NFTS and ML 1 

roads proposed for reopening within 1⁄2 mile of populated areas, neighboring federal land boundaries, 

wilderness boundaries, and private land boundaries. These miles act as a surrogate to indicate possible

conflict between NFTS users and other land owners may occur by alternative. This method was 

determined through a literature review of sound studies and reports (Martin, et al. 2005, Ouren, et al. 

2007, and Turina, et al. 2006).
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Chapter 3: Affected Environment and Environmental Consequences – 3.07. Recreation and Visual Resources

Tahoe National Forest – 667

Table 3.07-11. Number of miles of routes proposed for addition to the NFTS under each alternative within 1⁄2 

mile of neighboring private and federal lands (includes roads and trails)

Mileage Proposed to be Added to the NFTS

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Route Additions to the NFTS 0.0 33.7 0.0 13.8 43.6 36.8 19.1

Reopening ML 1 Roads to 

motorized use

0.0 0.0 0.0 0.0 19.7 1.7 0.0

Route Addition Subtotal 0.0 33.7 0.0 13.8 63.3 38.5 19.1

Total Mileage in Alternative –

including NFTS

2,317.0a 1,418.0 1,384.0 1,398.0 1,447.0 1,422.0 1,403.0

Percent Change 0% 2% 0% 1% 4% 3% 1%

a For Alternative 1, Total Mileage in alternative includes the existing NFTS and the inventoried unauthorized OHV routes within 1⁄2 

mile of neighboring private and federal lands and wilderness.

Totals may include slight errors due to rounding.

Recreation: Affected Environment

The Tahoe National Forest (TNF) is strategically located between the greater metropolitan areas of 

Sacramento and Reno linked by Interstate 80. The Forest is less than an hour drive from both cities and 

the San Francisco Bay Area is about a three-hour drive. The Forest offers high mountain scenery, 

attractive reservoirs and lakes, beautiful river canyons, and a wide range of campgrounds and trails for 

Forest visitors.

The combination of proximity to urban areas and attractive recreation opportunities results in high 

visitation levels. Over the years the TNF has ranked nationally in the top twenty of total Forest visitors. 

Based on the National Visitor Use Monitoring results, the TNF received an estimated 1,791,300 visits in 

2005. Based on this survey, approximately 40 percent of visitors are primarily focused on winter sports, 

another 25 percent come to hike/walk or fish, and the remaining 35 percent is split between motorized and 

non-motorized activities (see Tables 3.07-12 and 13).

Recreational Experiences 

The Forest offers a diverse range of motorized and non-motorized recreational experiences throughout the 

year. Motorized recreation involves the use of highway-licensed passenger cars, sport utility vehicles 

(SUVs), dual-sport motorcycles, off-highway vehicles (OHVs), four-wheel-drive-vehicles (4WDs), allterrain vehicles (ATVs), dirt bikes, snowmobiles, and motorized boats. Non-motorized recreational 

activities include hiking, fishing, bicycling, cross country skiing, camping, swimming, horseback riding, 

hunting, snowshoeing, and backpacking (USDA Forest Service, 2005). Motorized access is the primary 

form of access to non-motorized recreation activity destinations on the Forest.

The Tahoe NF consists of about 836,000 acres available for public use. Approximately 82,000 acres, 

or about 10 percent of the Forest, is currently closed to motor vehicle use. Areas closed to motor vehicle 

use include: research natural areas, Granite Chief Wilderness, the North Fork American River Canyon, an 

Experimental Forest, the Grouse Ridge Vehicle closure area, and portions of Inventoried Roadless Areas.
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Chapter 3: Affected Environment and Environmental Consequences – 3.07. Recreation and Visual Resources

668 – Tahoe National Forest

Available lands outside of the management areas listed above results in about 733,316 acres of land 

currently open for cross country motorized travel.

Developed recreation facilities attract a large number of the motorized recreation users. The Forest 

provides 77 family campgrounds, 12 group campgrounds, 20 picnic grounds, 35 trailheads (this includes 

OHV trailheads), 16 boating sites, 158 recreation residences, 8 organization camps, and 4 resorts. All of 

these facilities can support general motor vehicle use and are used as a base for both motorized and nonmotorized activities.

Dispersed recreation is outdoor recreation occurring over broad expanses of land or water and 

accounts for the majority of Forest recreation use. Dispersed recreation opportunities, especially dispersed 

camping opportunities, are highly valued by Forest visitors. Some dispersed sites have been used by 

several generations of visitors. Additionally, some dispersed recreation sites have a uniquely identifiable 

sense of place with vistas and scenery viewing opportunities. 

Trails

The existing Forest trail system provides both the trail experience and access to additional dispersed 

recreational activities. Overall, the Forest trail system is 763 miles in length. That includes 329 miles of 

motorized trail, broken down by 169 miles for motorcycles only, 26 miles for motorcycles and ATVs, and 

134 miles of high clearance 4WD trails for Class II vehicles, ATVs, and motorcycles. The non-motorized 

trail system includes 434 total miles, with 289 designated for pedestrians, equestrians, and mountain 

bikes, while an additional 145 has been designated for hikers and equestrians only.

The Forest trail system includes a number of notable segments and areas. For hikers and equestrians, 

the Pacific Crest Trail follows the Sierra Crest through the middle of the Forest. The non-motorized South 

Yuba National Recreation Trail follows the South Fork of the Yuba River. The Western States Trail is not 

only home to the famous Western States 100 run and the 100-mile Tevis Cup equestrian race, but portions 

provide for challenging motorcycle riding. The Fordyce 4WD trail provides some of the most challenging 

four-wheeling in the Sierra. Sugar Pine is the closest OHV opportunity for residents in the Sacramento 

metropolitan area on the TNF. Sugar Pine provides a substantial and diverse trail system for motorcycles

and a more limited, moderate opportunity for ATV riders. The Truckee area motorized trails provide a 

flatter, more open vegetation experience largely for motorcycles and 4WD operators. The Burlington 

Ridge motorcycle trail system provides a moderate amount of tight singletrack trails winding through the 

trees, especially popular with local riders. The northern portion of the Yuba River Ranger District 

provides a difficult/extremely difficult singletrack motorcycle riding network in a remote, high-elevation 

setting, a rare opportunity in northern California. The Gold Valley area provides some moderate difficulty 

4WD and motorcycle opportunities in a remote setting, and includes some excellent dispersed camping 

opportunities.
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Chapter 3: Affected Environment and Environmental Consequences – 3.07. Recreation and Visual Resources

Tahoe National Forest – 669

Table 3.07-12. Tahoe NF visitor activity participation as reported in NVUM result (2005)

Activity Percent Participating Percent as Main Activity

Viewing Natural Features 53.6 5.6

Relaxing 36.6 3.3

Hiking / Walking 32.4 14.6

Downhill Skiing 32.4 29.3

Viewing Wildlife 36.3 0.3

Driving for Pleasure 15.9 2.8

Other Non-motorized 11.1 3.9

Fishing 15.3 10.7

Developed Camping 5.6 1.1

OHV Use 3.9 1.5

Primitive Camping 1.6 0.6

Nature Study 3.7 0.1

Hunting 2.2 1.5

Gathering Forest Products 1.5 0.1

Non-motorized Water 3.1 1.6

Motorized Water Activities 6.2 1.8

Picnicking 9.3 0.6

Cross country Skiing 5.0 3.4

Bicycling 7.7 5.8

Visiting Historic Sites 4.9 0.2

Backpacking 0.7 0.4

Resort Use 1.6 0.2

Snowmobiling 7.6 6.7

Other Motorized Activity 3.3 1.5

Horseback Riding 0.2 0.1

Nature Center Activities 1.9 0.0

Sightseeing 0.0 0.0

No Activity Reported 2.5 2.3

Total 100.0

Totals may include slight errors due to rounding

Travelways

The Yuba Donner National Forest Scenic Byway (YDSB) is a 170-mile motorized loop through three 

TNF ranger districts. This byway includes California State Highways 49, 89, and 20, Interstate 80, and a 

portion of old Highway 40 over Donner Pass. On the American River District, the Mosquito 

Ridge/Foresthill Drive loop showcases the same rich diversity of geology, history, plants, wildlife and 

rural communities found along the travelways of the rest of the Forest.

Based on the NVUM, there were 1,791,300 visits to NFS lands on the TNF during fiscal year 2005. 

This would mean that 284,817 visitors spent some time driving for pleasure, 69,861 used off-highway 

vehicles during their visit, and the primary activity for 26,686 visitors was off-highway vehicle use. Based 

on the 2005 year visits, when primary motorized uses are combined (including OHV use, driving for 

pleasure and other motorized activities), approximate visitor numbers equal 103,772. When primary nonmotorized uses are combined, (including backpacking, fishing, hiking/walking, horseback riding, 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment and Environmental Consequences – 3.07. Recreation and Visual Resources

670 – Tahoe National Forest

bicycling and other non-motorized activities), approximate visitor numbers equal 635,462 (Table 3.07-

13). Visitors seeking a quiet, non-motorized experience often utilize motorized vehicles to access 

trailheads, facilities, destinations, or geographic areas for non-motorized recreational activities.

Table 3.07-13. Approximate Tahoe NF visitors by type of main activity as reported in NVUM results (2005)

Type of Use NVUM Categories Percent as Main Activity Approximate Visitors in 2005

Camping Developed Camping

Primitive Camping

1.7 30,022

Hunting Hunting 1.5 26,686

Motorized Uses OHV use

Driving for Pleasure

Other Motorized Activity

5.8 103,772

Non-motorized 

Uses

Backpacking

Fishing

Hiking/Walking

Horseback Riding

Bicycling

Other Non-Motorized Activities

35.5 635,462

Other Activities Resort Use

Picnicking

Viewing Natural Features

Visiting Historic Sites

Nature Center Activities

Nature Study

Relaxing

Gathering Forest Products

Viewing Wildlife

10.4 185,136

Water Sports Motorized Water Activities

Non-motorized Water

3.4 61,712

Winter Sports Downhill Skiing;

Cross country Skiing;

Snowmobiling

39.4 707,179

Totals may include slight errors due to rounding

Recreation: Environmental Consequences

Considerations for all alternatives

This section discloses the environmental effects of each of the alternatives on recreation on the Forest. 

This analysis is focused on the effects of five management actions: (1) the prohibition of cross country 

motorized travel, (2) additions of unauthorized routes to the National Forest Transportation System 

(NFTS), (3) Establishment of motorized “Open Areas,” (4) changes to the existing NFTS, and (5) 

Amendments to the Forest Plan. These 5 management actions have indicators used to compare 

alternatives. The indicators were previously listed in the Recreation Measurement Indicators section 

under the Effects Analysis Methodology. Nearly all forest visitors, regardless of the purpose for their visit, 

use the motorized transportation system to reach their destination. Changes to traditionally accepted 
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Forest uses, such as cross country motorized travel, alters the diversity of motorized and non-motorized 

opportunities on the Forest. 

Short-term timeframe: 1 year

Long-term timeframe: 20 years.

Spatial boundary: The Forest boundary of 836,000 acres is the unit of spatial analysis.

Rationale: The effects measurement indicators are based on NFMA and Travel Management Rule 

requirements as well as significant issues raised during internal and public scoping.

Direct and Indirect Effects

Alternative 1 – No Action

Under the No Action Alternative, the existing condition as described in the affected environment section 

would continue. The Travel Management Rule would not be implemented, and a motor vehicle use map 

would not be produced. Motor vehicle travel by the public would not be limited to designated routes.

Unauthorized routes would continue to proliferate and have no status or authorization as NFTS facilities. 

Prohibition of cross country wheeled motorized vehicle travel. Alternative 1 would not prohibit

cross country motorized vehicle travel. Most of the cross country travel occurs on open terrain or on nonsystem routes and may appear to be rough roads, old trails, or old singletrack trails. It is anticipated that 

cross country motorized travel would continue, and probably increase throughout the Forest. This would 

occur immediately adjacent to known popular motorized areas, especially in areas of gentler terrain.

Although consistent with LRMP guidance for ROS, cross country motorized travel may affect ROS class 

settings in the short and long term. Motorized use could inadvertently spread to non-motorized areas, 

changing areas with non-motorized ROS class settings, such as semi-primitive non-motorized, to ROS 

classes with motorized settings such as semi-primitive motorized, roaded natural, or rural (refer to Table 

3.07-2). 

The short-term and long-term effects of cross country motorized travel include the increased potential 

for conflicts with users seeking a “quiet” recreation experience, as well as increasing dust and noise on 

neighboring private and federal lands. Under Alternative 1, at least 4.6 percent of the Forest (area of 

potential effects) would be affected by the dust, odors, and noise typically associated with the motorized 

use of the inventoried unauthorized routes and cross country motorized travel (refer to Table 3.07-3). In 

the long term, visitors seeking a “quiet” recreation experience would likely be displaced to the Granite 

Chief Wilderness, other currently designated non-motorized areas (e.g. Grouse Ridge), or higher 

elevations of the Forest where steep topography naturally restricts cross country motorized travel. For the 

impacts of motorized use on Inventoried Roadless Area qualities, see the Inventoried Roadless Areas and 

Special Areas (Section 3.09) of the document. 

Dispersed recreation is defined as outdoor recreation occurring over broad expanses of land or water 

and accounts for the majority of Forest recreation use. Access to dispersed recreation sites occurs on both 

the existing NFTS and unauthorized motorized routes. In Alternative 1, in both the short and long term, 

no change in motorized access to dispersed recreation activities would occur. 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment and Environmental Consequences – 3.07. Recreation and Visual Resources

672 – Tahoe National Forest

Under the No Action Alternative, motorized recreation opportunities on about 1,698 miles of 

unauthorized and/or closed routes would continue, and about 733,316 acres would continue to allow for 

unrestricted cross country motorized travel. The “Open Area” acreage and unauthorized motorized routes 

would not experience any changes or use restrictions. No net change in motorized recreation opportunities 

would occur, and as a result there would be no short or long term direct or indirect effects from any 

proposed new actions to motorized recreation opportunities. 

Indicators referenced:

• Measurement Indicator 1: Consistency with LRMP

• Measurement Indicator 2: Non-motorized recreation opportunity 

• Measurement Indicator 3: Motorized recreation opportunity

• Measurement Indicator 4: Type of motorized access to dispersed recreation

• Measurement Indicator 5: Impact of proposed changes to the NFTS on neighboring private and

federal lands (dust, noise, use conflicts).

Adding facilities (presently unauthorized roads and trails) to the NFTS. No additions to the 

existing NFTS would be made under Alternative 1. No direct or indirect effects would result, as no 

change would be made from the current management situation.

Indicators referenced:

• Measurement Indicator 3: Motorized recreation opportunity

Establish motorized “Open Areas.” No changes to the NFTS in regards to the establishment of 

motorized “Open Areas” would be made under this alternative. No direct or indirect effects would result, 

as no change would be made from the current management situation.

Indicators referenced: 

• Measurement Indicator 3: Motorized recreation opportunity

Changes to the existing NFTS [changing the vehicle class, season of use, and reopening ML 1 

roads]. No changes to the NFTS in regard to mixed use, maintenance level, or season of use would be 

made under this alternative. No Maintenance Level 1 (ML 1) roads are proposed to be reopened under 

Alternative 1, and no associated motorized access to dispersed recreation sites would be designated under 

this alternative (see Table 3.07-10). No direct or indirect effects would result, as no change would be 

made from the current management situation.

Indicators referenced: 

• Measurement Indicator 3: Motorized recreation opportunity

• Measurement Indicator 4: Type of motorized access to dispersed recreation

Amending the Forest Plan. No changes to the Forest Plan would be made under this alternative. No 

direct or indirect effects would result, as no change would be made from the current management 

situation.
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Chapter 3: Affected Environment and Environmental Consequences – 3.07. Recreation and Visual Resources

Tahoe National Forest – 673

Indicators referenced: 

• Measurement Indicator 1: Consistency with LRMP

Alternative 2 – Increased Motorized Recreation and Access Opportunities

Alternative 2 responds to the issue raised by the public during scoping of insufficient public motorized 

opportunities and motorized access for dispersed recreation in the Proposed Action. This alternative 

prohibits cross country travel, adds about 5 miles of road and 55 miles of motorized trail to the NFTS, 

establishes 2,649 acres (3 large reservoir areas and 1 play area) as motorized “Open Areas,” allows 399 

miles of mixed use, makes minor changes to route seasons of use, provides for motorized access to 182 

dispersed sites, and makes one amendment to the Forest Plan.

Prohibition of cross country wheeled motorized vehicle travel. Under Alternative 2, cross country 

motorized vehicle travel would be prohibited. The prohibition of wheeled motor vehicle use off the NFTS 

would have a beneficial effect on non-motorized recreation opportunities and would reduce negative 

impacts to populated areas and neighboring lands of various ownerships in the short and long terms by 

reducing noise, dust and physical presence of motorized vehicles. Prohibiting cross country motorized 

travel would also curtail on-going negative effects to visitors and NFS lands from motorized vehicles 

such as noise, dust and physical presence in the short and long terms. 

Compared to Alternative 1, prohibiting cross country motorized vehicle travel in Alternative 2 would 

result in a net loss of acreage available for motorized recreation. This prohibition of cross country travel 

will concentrate motorized use on designated roads and trails. The concentration of use resulting from 

prohibiting cross country travel in the action alternatives will outweigh any similar effects produced by 

differences between the action alternatives. This concentration of use is expected to increase the density 

of riders/drivers per mile of route, potentially changing the motorized experience on the Tahoe National 

Forest. Most OHV enthusiasts are expected to continue to return to the areas they currently visit, but will 

alter their expectations (and riding styles) to account for the increased density. Rider/driver adjustments 

may include changing the time or day of visit, adapting a more defensive riding style (slower speeds, 

more attentive to oncoming traffic), and improved riding etiquette (use of hand signals). A small 

percentage of users may be displaced to different areas on the TNF, or adjacent riding areas. The cross 

country prohibition would also reduce motorized access to dispersed recreation activities. However, this 

alternative establishes the greatest number of “Open Area” of any alternative (see “Open Area” effects 

below). Although motorized recreation opportunities on NFS lands would be greatly reduced, other 

motorized recreation opportunities would be available and the miles of NFTS would be increased.

Indicators referenced:

• Measurement Indicator 2: Non-motorized recreation opportunity 

• Measurement Indicator 3: Motorized recreation opportunity

• Measurement Indicator 4: Type of motorized access to dispersed recreation

• Measurement Indicator 5: Impact of proposed changes to the NFTS on neighboring private and 

federal lands (dust, noise, use conflicts).
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment and Environmental Consequences – 3.07. Recreation and Visual Resources

674 – Tahoe National Forest

Adding facilities (presently unauthorized roads and trails) to the NFTS. Adding unauthorized 

roads and trails may negatively affect (short and long term) non-motorized opportunities due to an 

increase in noise, dust, physical presence, possible use conflicts and displacement. Under Alternative 2, 

an additional 0.3 percent of the Forest would be affected by the dust, odors, and noise typically associated 

with the proposed route and area additions. Alternative 2 would also include two road additions that 

would cross the non-motorized Pacific Crest Trail, requiring the installation of vehicle barriers to prevent 

motorized use on the PCT. When compared to the other alternatives, the proposed route additions under 

this alternative would tie for the fourth highest impact on the Forest’s “quiet” recreation opportunities (see 

Table 3.07-3). Alternative 2 proposes 33.7 miles of road and trail additions within 1⁄2 mile of neighboring 

lands, potentially having the fourth greatest noise, dust, and physical presence impacts on neighboring 

private and federal lands when compared to the other alternatives (see Table 3.07-11). Motorized roads, 

trails, and areas would be administratively defined and published on a motor vehicle use map (MVUM). 

Recreationists would be able to better plan recreational pursuits based on an individual’s unique 

expectations. As a result, the frequency of user conflicts between non-motorized and motorized recreation 

users would likely decrease in the short and long terms.

Alternative 2 would provide the third highest amount of both road (5.0 miles) and motorized trail 

(54.6 miles) additions to the NFTS, presenting a beneficial effect on motorized recreation opportunities 

for a diversity of vehicle classes and access to dispersed recreation. Most (3.7 miles) of the road additions 

would be Open to All Vehicles year-round, or until snow prohibits access. The remaining 1.1 miles would 

be spread over three seasons varying from seven to nine months in length based on LRMP designations 

for the areas where these roads are added (see Table 3.07-4). A majority (35.3 miles) of the motorized trail 

additions would be open year-round, with 15.9 miles open to high-clearance 4WD, 3.4 miles open to 

ATVs and motorcycles, and 16.0 miles open to motorcycles. The remaining 19.2 miles would be open 

from May 1 to December 31 with 8.4 miles open to high-clearance 4WD, 0.9 miles open to ATVs and 

motorcycles, and 9.9 miles open to motorcycles (see Table 3.07-7).

Adding presently unauthorized roads and trails to the NFTS would have a beneficial effect on 

motorized opportunities by providing additional miles of recreation opportunities. The proposed trail 

additions in Alternative 2 contribute to a variety of experiences with easy-to-extremely difficult 

riding/driving experiences, especially for 4WD and motorcycle operators (see Table 3.07-8). The 

proposed route additions also contribute to the continuity of the motor-touring opportunities by reducing 

dead-end routes, increasing loop and connector opportunities, and providing access to a diversity of 

dispersed recreation activities, providing beneficial effects to motorized recreation opportunities. The 

season of use restrictions on proposed road and trail additions may have a negative effect in the short and 

long terms to motorized opportunities by reducing mileage of motorized opportunity during the closure 

and a beneficial effect to non-motorized opportunities by increasing the acreage available for nonmotorized activities during the closure. As shown in Table 3.07-10, Alternative 2 provides motorized 

access to a total of 182 dispersed recreation sites, providing a beneficial effect to motorized recreation 

opportunities. Alternative 2 provides the fourth most motorized access to dispersed recreation sites when 

compared to the other alternatives.
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Indicators referenced:

• Measurement Indicator 2: Non-motorized recreation opportunity 

• Measurement Indicator 3: Motorized recreation opportunity

• Measurement Indicator 4: Type of motorized access to dispersed recreation

• Measurement Indicator 5: Impact of proposed changes to the NFTS on neighboring private and 

federal lands (dust, noise, use conflicts).

Establish motorized “Open Areas.” Alternative 2 proposes 4 motorized “Open Areas” consisting of 

3 large reservoir areas at Stampede/ Prosser/Boca and 1 play area at Greenhorn, totaling 2,649 acres, for 

cross country motorized travel year-round (see Table 3.07-9). Establishment of presently unauthorized 

“Open Areas” may have a negative effect in both short and long term context for non-motorized 

opportunities due to an increase in noise, dust, physical presence, possible use conflicts and displacement. 

These “Open Areas” within 1⁄2 mile of neighboring private and federal lands, may also contribute to this 

alternative potentially having the fourth greatest noise, dust, and physical presence impacts on 

neighboring private and federal lands when compared to the other alternatives (see Table 3.07-3). This 

impact would be higher in the Greenhorn areas because of concerns from adjacent landowners, as 

opposed to the lands around the reservoirs that are largely managed by the Forest Service. In the reservoir 

areas, a likely indirect effect of the “Open Area” designation would be to spread the participation in 

numerous non-motorized sports including picnicking, swimming, and dog walking around the shoreline 

rather than concentrating those impacts at the terminus of routes leading to the water. 

This is the only alternative to establish “Open Area” opportunities for operators of non-highway legal 

vehicles, and the greater of two alternatives to include “Open Area” opportunities to Open to Highwaylegal use, providing a beneficial effect on motorized recreation opportunities for a diversity of vehicle 

classes and access to dispersed recreation beyond the existing Prosser Pits. Just north of Truckee, the 

Boca, Prosser, and Stampede reservoirs would provide 2,589 acres of motorized opportunity along the 

shoreline, below the high water mark, for access to camping, boating, and day-use activities. The 

Greenhorn area would provide 60 acres of “Open Area” opportunity in a hydraulically mined area just 

outside of Nevada City that is especially popular with local 4WD drivers.

Establishing “Open Areas” would have a beneficial effect on motorized opportunities and would 

contribute to a variety of motorized experiences found on the TNF. A possible indirect effect would be to 

decrease the density of users in the existing Prosser Pits OHV Open Area. In addition, these four “Open 

Areas” would serve as quasi-dispersed sites themselves accentuating the 182 dispersed sites proposed to 

be added in this alternative, contributing to Alternative 2 ranking as the fourth greatest alternative in 

regard to motorized access to dispersed recreation sites when compared to the other alternatives.

Compared to the other alternatives, Alternative 2 would establish more acres of “Open Area” 

opportunities than any alternative (except Alternative 1 which would allow cross country travel).

Indicators referenced:

• Measurement Indicator 2: Non-motorized recreation opportunity 

• Measurement Indicator 3: Motorized recreation opportunity
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Chapter 3: Affected Environment and Environmental Consequences – 3.07. Recreation and Visual Resources

676 – Tahoe National Forest

• Measurement Indicator 4: Type of motorized access to dispersed recreation

• Measurement Indicator 5: Impact of proposed changes to the NFTS on neighboring private and 

federal lands (dust, noise, use conflicts).

Changes to the existing NFTS [changing the vehicle class, season of use, and reopening

ML 1 roads]. Proposals to change the vehicle class of NFTS routes to provide more mixed use would 

benefit motorized recreation by increasing the diversity of motorized opportunities (and looping 

opportunities). Changes in vehicle class that restrict motor vehicle types on NFTS routes would 

negatively affect motorized recreation diversity. A change in maintenance level through downgrading 

would increase the diversity of motorized opportunities (and looping opportunities); upgrading the road 

class would decrease the diversity of the motorized opportunities. 

Alternative 2 proposes mixed use on about 398.7 miles of NFTS roads (refer to Table 3.07-5). 

Alternatives 2 and 5 are the alternatives that provide the most mixed use. Mixed use on NFTS roads 

would benefit motorized recreation by increasing the diversity of motorized opportunities. The proposed 

changes to the NFTS also contribute to the continuity of the motor-touring opportunities by reducing 

dead-end routes, increasing loop and connector opportunities, and providing access to a diversity of 

dispersed recreation activities for non-highway-legal vehicle operators, providing beneficial effects to 

motorized recreation opportunities. However, the authorization of mixed use on the NFTS could increase 

the likelihood that adjacent private lands would experience intrusion by and impacts from OHVs, an 

impact to the affected landowners who may currently experience high levels of trespass from 

unauthorized OHV use.

Season of use restrictions on proposed road and trail additions and changes in Maintenance Level 

may have a negative effect in the short and long terms to motorized opportunities by reducing mileage of 

motorized opportunity during the closure and a beneficial effect to non-motorized opportunities by 

increasing the acreage available for non-motorized activities during the closure. In Alternative 2, 10.5 

miles of deer winter range seasonal restrictions are lifted (see Table 3.07-6), providing beneficial effects 

to motorized recreation opportunities in the Management Area 84 (Humbug-Sailor), requiring a Forest 

Plan amendment. This lifting of these restrictions would be especially beneficial to Sacramento-area 

riders who could access the Sugar Pine area quickly, during the winter season when the supply of regional 

motorized opportunities is greatly reduced due to deep snow.

No Maintenance Level 1 roads are proposed to be reopened under this alternative (see Tables 3.07-4 

and 7). Dispersed recreation sites associated with reopening ML 1 roads would not be accessible to 

motorized use under Alternative 2 (refer to Table 3.07-10). No direct or indirect access effects would 

result, as no change would be made from the current management situation.

Indicators referenced:

• Measurement Indicator 2: Non-motorized recreation opportunity 

• Measurement Indicator 3: Motorized recreation opportunity

• Measurement Indicator 4: Type of motorized access to dispersed recreation
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• Measurement Indicator 5: Impact of proposed changes to the NFTS on neighboring private and 

federal lands (dust, noise, use conflicts).

Amending the Forest Plan. Adding unauthorized roads and trails to the NFTS would be consistent 

with the ROS as allocated in the LRMP. All routes proposed for addition to the NFTS comply with the 

ROS class in the associated management area. All proposed route additions under this alternative would 

be located in semi-primitive motorized, roaded natural, or rural ROS classes. However, in regard to a 

change in season of use (see previous section), the lifting of the deer winter range seasonal restrictions 

would require a Forest Plan amendment to remove the November 1 to May 1 seasonal closure in the 

Sugar Pine area (Management Area 84, Humbug Sailor)(see Table 3.07-1).

Indicators referenced:

• Measurement Indicator 1: Consistency with LRMP

Alternative 3 – Cross country Travel Prohibition Only – No Changes to the Existing NFTS

Alternative 3 would prohibit cross country motorized travel and proposes no new additions or changes to 

the existing NFTS roads and trails. This alternative also provides a baseline for comparing the impacts of 

other alternatives that propose changes to the NFTS. None of the unauthorized roads, trails, or areas 

would be added to the NFTS. Alternative 3 responds to the issues of quiet recreation, and potential 

adverse impacts associated with motorized roads and trails. This alternative does not change mixed use 

areas and does not provide motorized access to any additional dispersed sites beyond the areas accessed 

by the existing NFTS. This alternative makes no amendments to the Forest Plan.

Prohibition of cross country wheeled motorized vehicle travel. Alternative 3 would prohibit cross 

country motorized travel with motorized recreation restricted to existing NFTS roads and trails. The 

prohibition of wheeled motor vehicle use off the NFTS would have a beneficial effect on non-motorized 

recreation opportunities and would reduce negative impacts to populated areas and neighboring lands of 

various ownerships in the short and long terms by reducing noise, dust and physical presence of 

motorized vehicles. Prohibiting cross country motorized travel would also curtail on-going negative 

effects from motorized vehicles such as noise, dust, and physical presence in the short and long terms.

Compared to Alternative 1, prohibiting cross country motorized vehicle travel in Alternative 3 would 

result in a loss of acreage available for motorized recreation. Alternative 3 would provide no opportunities 

for cross country motorized travel, resulting in a negative impact on motorized recreation opportunities.

This prohibition of cross country travel will concentrate motorized use on designated roads and trails. The 

concentration of use resulting from prohibiting cross country travel in the action alternatives will 

outweigh any similar effects produced by differences between the action alternatives. This concentration 

of use is expected to increase the density of riders/drivers per mile of route, potentially changing the 

motorized experience on the Tahoe National Forest. Most OHV enthusiasts are expected to continue to 

return to the areas they currently visit, but will alter their expectations (and riding styles) to account for 

the increased density. Rider/driver adjustments may include changing the time or day of visit, adapting a 

more defensive riding style (slower speeds, more attentive to oncoming traffic), and improved riding 
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678 – Tahoe National Forest

etiquette (use of hand signals). A small percentage of users may be displaced to different areas on the 

TNF, or adjacent riding areas. The cross country prohibition would also reduce looping opportunities and 

motorized access to dispersed recreation activities. Alternative 3 represents the current condition except 

for prohibiting cross country motorized travel. Motorized use would no longer occur on unauthorized 

routes and all currently unauthorized routes would naturally rehabilitate. Although motorized recreation 

opportunities on open acreage would not be provided, other motorized recreation opportunities would be 

available.

Indicators referenced:

• Measurement Indicator 2: Non-motorized recreation opportunity 

• Measurement Indicator 3: Motorized recreation opportunity

• Measurement Indicator 4: Type of motorized access to dispersed recreation

• Measurement Indicator 5: Impact of proposed changes to the NFTS on neighboring private and 

federal lands (dust, noise, use conflicts).

Adding facilities (presently unauthorized roads and trails) to the NFTS. No additions to the 

NFTS would be made under Alternative 3. No direct effects would result, as no change would be made 

from the current management situation. When compared to the other alternatives, this alternative provides 

the most “quiet” recreation opportunities (see Table 3.07-3) and provides the least risk of possible impact 

to neighboring private and Federals lands and wilderness areas in the short and long terms (see Table 

3.07-11). Production of a motor vehicle use map (MVUM) would allow recreationists to better plan 

recreational pursuits. As a result, the frequency of user conflicts between non-motorized and motorized 

recreation users would likely decrease in the short and long terms.

Alternative 3 would provide an identical number of miles of designated motorized opportunity 

(existing NFTS) as the current condition (Alternative 1), and provides the least amount of motorized 

recreation opportunities when compared to the other action alternatives (see Tables 3.07-4 and 7). 

Dispersed recreation sites associated with additions to the NFTS would not be accessible to motorized use 

under Alternative 3 (refer to Table 3.07-10). Alternative 3 provides the least amount of motorized access 

to dispersed recreation sites of any alternative. Additionally, some dispersed sites with vistas and scenic 

viewing opportunities may no longer be easily accessible. An indirect effect would be a reduction in 

opportunities to combine roads and trails to make larger loops. Compared to all alternatives, Alternative 3 

provides the least opportunities for motorized use and looping opportunities.

Indicators referenced:

• Measurement Indicator 2: Non-motorized recreation opportunity

• Measurement Indicator 3: Motorized recreation opportunity

• Measurement Indicator 4: Type of motorized access to dispersed recreation

• Measurement Indicator 5: Impact of proposed changes to the NFTS on neighboring private and 

federal lands (dust, noise, use conflicts).
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Establish motorized “Open Areas.” Alternative 3 does not propose the establishment of new “Open 

Areas” (refer to Table 3.07-9). No direct effects would result, as no change would be made from the 

current management situation. However, a possible indirect effect would be to increase the density of 

users in the existing Prosser Pits OHV “Open Area.” Compared to the other alternatives, Alternative 3 

would provide fewer acres of designated “Open Area” opportunities than Alternatives 2 and 6, and an 

equal amount as Alternatives 1, 4, 5, and 7.

Indicators referenced:

• Measurement Indicator 3: Motorized recreation opportunity

Changes to the existing NFTS [changing the vehicle class, season of use, and reopening ML 1 

roads]. No changes to the NFTS in regard to mixed use, maintenance level, or season of use would be 

made under Alternative 3. No Maintenance Level 1 roads are proposed to be reopened under this 

alternative (see Tables 3.07-4 and 7). Dispersed recreation sites associated with reopening ML 1 roads 

would not be accessible to motorized use under Alternative 3 (refer to Table 3.07-10). No direct or 

indirect access effects would result, as no change would be made from the current management situation.

Indicators referenced: 

• Measurement Indicator 3: Motorized recreation opportunity

• Measurement Indicator 4: Type of motorized access to dispersed recreation

Amending the Forest Plan. No changes to the Forest Plan would be made under Alternative 3. No 

direct or indirect effect would result, as no change would be made from the current management situation.

Indicators referenced: 

• Measurement Indicator 1: Consistency with LRMP

Alternative 4 – Increased Resource Protection

Alternative 4 prohibits cross country motorized travel and adds fewer routes to the NFTS than the 

Proposed Action. This alternative responds to the concerns of quiet recreation use, and natural resource 

impacts. This alternative prohibits cross country travel, adds about 4 miles of road and 23 miles of 

motorized trail to the NFTS, establishes no new acres as motorized “Open Areas,” allows 3 miles of 

mixed use, makes 1,312 miles of changes in seasons of use, and provides for motorized access to 107 

dispersed sites. This alternative makes no amendments to the Forest Plan.

Prohibition of cross country wheeled motorized vehicle travel. Under Alternative 4, cross country 

motorized vehicle travel would be prohibited. The prohibition of wheeled motor vehicle use off the NFTS 

would have a beneficial effect on non-motorized recreation opportunities and would reduce negative 

impacts to populated areas and neighboring lands of various ownerships in the short and long terms by 

reducing noise, dust and physical presence of motorized vehicles. Prohibiting cross country motorized 

travel would also curtail on-going negative effects from motorized vehicles such as noise, dust and 

physical presence in the short and long terms. 
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Chapter 3: Affected Environment and Environmental Consequences – 3.07. Recreation and Visual Resources

680 – Tahoe National Forest

Compared to Alternative 1, prohibiting cross country motorized vehicle travel in Alternative 4 would 

result in a net loss of acreage available for motorized recreation. Alternative 4 would provide no 

opportunities for cross country motorized travel, resulting in a negative impact on motorized recreation 

opportunities. This prohibition of cross country travel will concentrate motorized use on designated roads 

and trails. The concentration of use resulting from prohibiting cross country travel in the action 

alternatives will outweigh any similar effects produced by differences between the action alternatives.

This concentration of use is expected to increase the density of riders/drivers per mile of route, potentially 

changing the motorized experience on the Tahoe National Forest. Most OHV enthusiasts are expected to 

continue to return to the areas they currently visit, but will alter their expectations (and riding styles) to 

account for the increased density. Rider/driver adjustments may include changing the time or day of visit, 

adapting a more defensive riding style (slower speeds, more attentive to oncoming traffic), and improved 

riding etiquette (use of hand signals). A small percentage of users may be displaced to different areas on 

the TNF, or adjacent riding areas. The cross country prohibition would also reduce motorized access to 

dispersed recreation activities. The loss of available open acreage is somewhat offset, however, by the 

proposed addition of motorized routes to the NFTS. Although motorized recreation opportunities on open 

acreage would not be provided, other motorized recreation opportunities would be available and the 

NFTS would be increased.

Indicators referenced:

• Measurement Indicator 2: Non-motorized recreation opportunity 

• Measurement Indicator 3: Motorized recreation opportunity

• Measurement Indicator 4: Type of motorized access to dispersed recreation

• Measurement Indicator 5: Impact of proposed changes to the NFTS on neighboring private and 

federal lands (dust, noise, use conflicts).

Adding facilities (presently unauthorized roads and trails) to the NFTS. Adding unauthorized 

roads and trails may have a negative effect on (short and long term) non-motorized opportunities due to 

increases in noise, dust, physical presence, possible use conflicts and displacement. Under Alternative 4, 

about 0.1 percent of the Forest would be affected by the dust, odors, and noise typically associated with 

the proposed route additions. When compared to the other alternatives, the proposed route additions under 

Alternative 4 would have less impact on the Forest’s “quiet” recreation opportunities than Alternatives 1,

2, 5, 6, and 7 and slightly more impact on the Forest’s “quiet” recreation opportunities than Alternative 3 

(see Table 3.07-3). Alternative 4 proposes 13.8 miles of road and trail route additions within 1⁄2 mile of 

neighboring private and federal lands, potentially increasing noise, dust, and physical presence impacts on 

neighboring private and federal lands. When compared to the other alternatives, Alternative 4 would have 

less impact on neighboring lands than Alternatives 1, 2, 5, 6 and 7 and more impact than Alternative 3 

(see Table 3.07-11). Production of a motor vehicle use map (MVUM) would allow recreationists to better 

plan recreational pursuits. As a result, the frequency of user conflicts between non-motorized and 

motorized recreation users would likely decrease in the short and long terms.
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Compared to the other alternatives, Alternative 4 would provide the fourth largest amount of road 

additions (3.7 miles) to the NFTS. Alternative 4 would add more miles of road than Alternative 7, but less 

than Alternatives 2, 5, and 6 (see Table 3.07-4). Alternative 4 would provide the third least amount of 

motorized trail (22.5 miles) additions to the NFTS. Alternatives 1 and 3 would not add any roads or trails 

to the system (see Table 3.07-7). These additions beneficially affect motorized recreation opportunities for 

a diversity of vehicle classes. All (3.7 miles) of the road additions would be Open to All Vehicles 

seasonally, with most of the mileage open May 1 to December 31, but 0.2 miles would be open May 1 to 

November 1. Most (21.4 miles) of the motorized trail additions would be open from May 1 to December 

31, with the remaining 1.2 miles open April 1 to December 31. Of the 22.6 miles of total trail additions, 

5.6 miles would be open to high-clearance 4WD, 2.9 miles would be open to ATVs and motorcycles, and 

14.1 miles would be open to motorcycles.

Adding unauthorized roads and trails to the NFTS would have a beneficial effect on motorized 

opportunities by providing additional miles of recreation opportunities. The proposed trail additions in 

Alternative 4 contribute to a variety of experiences with easy-to-extremely difficult riding/driving 

experiences, especially for 4WD operators (see Table 3.07-8). The proposed route additions also 

contribute to the continuity of the motor-touring opportunities by reducing dead-end routes, increasing 

loop and connector opportunities, and providing access to a diversity of dispersed recreation activities, 

providing beneficial effects to motorized recreation opportunities. The season of use restrictions on 

proposed road and trail additions may have a negative effect in the short and long terms to motorized 

opportunities by reducing mileage of motorized opportunity during the closure and a beneficial effect to 

non-motorized opportunities by increasing the acreage available for non-motorized activities during the 

closure. As shown in Table 3.07-10, Alternative 4 provides motorized access to a total of 107 dispersed 

recreation sites, providing a beneficial effect to motorized recreation opportunities. When compared to the 

other alternatives, Alternative 4 provides less motorized access to dispersed recreation than Alternatives 1, 

2, 5, and 6, but more motorized access than Alternatives 3 and 7.

Indicators referenced:

• Measurement Indicator 2: Non-motorized recreation opportunity 

• Measurement Indicator 3: Motorized recreation opportunity

• Measurement Indicator 4: Type of motorized access to dispersed recreation

• Measurement Indicator 5: Impact of proposed changes to the NFTS on neighboring private and 

federal lands (dust, noise, use conflicts).

Establish motorized “Open Areas.” Alternative 4 does not propose the establishment of any new 

“Open Areas” to the NFTS (refer to Table 3.07-9). No direct effects would result, as no change would be 

made from the current management situation. However, a possible indirect effect would be to increase the 

density of users in the existing Prosser Pits OHV “Open Area.” Compared to the other alternatives, 

Alternative 4 would provide fewer acres of “Open Area” motorized recreation opportunities than 

Alternatives 2 and 6, and an equal amount as Alternatives 1, 3, 5, and 7.
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682 – Tahoe National Forest

Indicators referenced: 

• Measurement Indicator 3: Motorized recreation opportunity

Changes to the existing NFTS [changing the vehicle class, season of use, and reopening ML 1 

roads]. Proposals to change the vehicle class of NFTS routes to provide more mixed use would benefit 

motorized recreation by increasing the diversity of motorized opportunities (and looping opportunities). 

Changes in vehicle class that restrict motor vehicle types on NFTS routes would negatively affect 

motorized recreation diversity. A change in maintenance level through downgrading would increase the 

diversity of motorized opportunities (and looping opportunities); upgrading the road class would decrease 

the diversity of the motorized opportunities.

Alternative 4 proposes mixed use on about 3.4 miles of NFTS roads (see Table 3.07-5). Alternatives 4 

and 7 are tied for the third largest amount of mixed use of any alternative. Mixed use on NFTS roads 

would benefit motorized recreation by increasing the diversity of motorized opportunities. The proposed 

changes to the NFTS also contribute to the continuity of the motor-touring opportunities by reducing 

dead-end routes, increasing loop and connector opportunities, and providing access to a diversity of 

dispersed recreation activities for non-highway-legal vehicle operators, providing beneficial effects to 

motorized recreation opportunities. However, the authorization of mixed use on the NFTS could increase 

the likelihood that adjacent private lands would experience intrusion by and impacts from OHVs, an 

impact to the affected landowners who may experience high levels of trespass from unauthorized OHV 

use. Although Alternative 4 would provide less motorized recreation opportunity through mixed use when 

compared to Alternatives 1, 2, 5, and 6, it provides more motorized recreation opportunity on existing 

NFTS roads through mixed use when compared to Alternative 3, and equal to Alternative 7.

Season of use restrictions on proposed road and trail additions and changes in Maintenance Level 

may have a negative effect in the short and long terms to motorized opportunities by reducing mileage of 

motorized opportunity during the closure and a beneficial effect to non-motorized opportunities by 

increasing the acreage available for non-motorized activities during the closure. In Alternative 4, 1,312.1 

miles of wet weather seasonal restrictions are added to minimize erosion and protect water quality (see 

Table 3.07-6), closing motorized opportunities from January 1 to May 31 in the Burlington area and 

January 1 to April 30 on the remainder of the Forest on native surface roads and motorized trails. In 

regard to season of use motorized opportunities, Alternative 4 has fewer miles of seasonal closure than 

Alternatives 5 and 6, but has more seasonal closures than Alternatives 1, 2, 3, and 7.

In Alternative 4, 0.1 miles of ML 1 road would be reopened as a motorcycle trail with a season of use 

of April 1 to December 31 (see Table 3.07-7). The season of use restriction on the proposed reopening of 

this ML 1 road to a motorized trail may have a minor negative effect in the short and long terms to

motorized opportunities by reducing mileage of motorized opportunity during the closure and a minor 

beneficial effect to non-motorized opportunities by increasing the acreage available for non-motorized 

activities during the closure. Alternative 4 would reopen a total of 0.1 miles of ML 1, slightly more than 

Alternatives 1, 2 and 3, and less than Alternatives 5, 6, and 7. No motorized access to associated dispersed 
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recreation would be designated under this alternative (see Table 3.07-10). No direct or indirect access 

effects would result, as no change would be made from the current management situation.

Indicators referenced:

• Measurement Indicator 2: Non-motorized recreation opportunity 

• Measurement Indicator 3: Motorized recreation opportunity

• Measurement Indicator 4: Type of motorized access to dispersed recreation

• Measurement Indicator 5: Impact of proposed changes to the NFTS on neighboring private and 

federal lands (dust, noise, use conflicts).

Amending the Forest Plan. No changes to the Forest Plan would be made under Alternative 4. No 

direct or indirect effect would result, as no change would be made from the current management situation.

Indicators referenced: 

• Measurement Indicator 1: Consistency with LRMP 

Alternative 5 – Increased Motorized Recreation Access plus Reopening Maintenance Level 1 and 

Temporary Roads

Alternative 5 was developed to address the issue of providing sufficient wheeled motorized public access 

to TNF lands as well as public concerns about reduced motorized recreation opportunities. This 

alternative prohibits cross country travel, adds about 5 miles of road and 75 miles of motorized trail to the 

NFTS, establishes no new acres as motorized “Open Areas,” allows 399 miles of mixed use, makes 1,397 

miles of changes in season of use, provides for motorized access to 188 dispersed sites, and makes one 

amendment to the Forest Plan.

Prohibition of cross country wheeled motorized vehicle travel. Under Alternative 5, cross country 

motorized vehicle travel would be prohibited. The prohibition of wheeled motor vehicle use off the NFTS 

would have a beneficial effect on non-motorized recreation opportunities and would reduce negative 

impacts to populated areas and neighboring lands of various ownerships in the short and long terms by 

reducing noise, dust and physical presence of motorized vehicles. Prohibiting cross country motorized 

travel would also curtail on-going negative effects from motorized vehicles such as noise, dust and 

physical presence in the short and long terms.

Compared to Alternative 1, prohibiting cross country motorized vehicle travel in Alternative 5 would 

result in a net loss of acreage available for motorized recreation. Alternative 5 would provide no 

opportunities for cross country motorized travel, resulting in a negative impact on motorized recreation 

opportunities. This prohibition of cross country travel will concentrate motorized use on designated roads 

and trails. The concentration of use resulting from prohibiting cross country travel in the action 

alternatives will outweigh any similar effects produced by differences between the action alternatives.

This concentration of use is expected to increase the density of riders/drivers per mile of route, potentially 

changing the motorized experience on the Tahoe National Forest. Most OHV enthusiasts are expected to 

continue to return to the areas they currently visit, but will alter their expectations (and riding styles) to 
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684 – Tahoe National Forest

account for the increased density. Rider/driver adjustments may include changing the time or day of visit, 

adapting a more defensive riding style (slower speeds, more attentive to oncoming traffic), and improved 

riding etiquette (use of hand signals). A small percentage of users may be displaced to different areas on 

the TNF, or adjacent riding areas. The cross country prohibition would also reduce motorized access to 

dispersed recreation activities. The loss of available open acreage is somewhat offset, however, by the 

proposed addition of motorized routes to the NFTS. Although motorized recreation opportunities on open 

acreage would not be provided, other motorized recreation opportunities would be available and the 

NFTS would be increased.

Indicators referenced:

• Measurement Indicator 2: Non-motorized recreation opportunity 

• Measurement Indicator 3: Motorized recreation opportunity

• Measurement Indicator 4: Type of motorized access to dispersed recreation

• Measurement Indicator 5: Impact of proposed changes to the NFTS on neighboring private and 

federal lands (dust, noise, use conflicts).

Adding facilities (presently unauthorized roads and trails) to the NFTS. Adding unauthorized 

roads and trails may have a negative effect (short and long term) on non-motorized opportunities due to 

an increase in noise, dust, physical presence, possible use conflicts and displacement. Under Alternative 

5, an additional 0.4 percent of the Forest acreage would be affected by the dust, odors, and noise 

associated with the proposed route additions. Alternative 5 would also include two road additions that 

would cross the non-motorized Pacific Crest Trail, requiring the installation of vehicle barriers to prevent 

motorized use on the PCT. When compared to the other alternatives, the proposed route additions under 

Alternative 5 would have the second most impact on the Forest’s “quiet” recreation opportunities of any 

alternative, behind Alternative 1 (see Table 3.07-3). Alternative 5 proposes 63.3 miles of road and trail 

route additions within 1⁄2 mile of neighboring lands, potentially having some noise, dust, and physical 

presence impacts on neighboring private and federal lands. When compared to the other alternatives, 

Alternative 5 would have the largest percent change of any alternative (see Table 3.07-11). Production of 

a motor vehicle use map (MVUM) would allow recreationists to better plan recreational pursuits. As a 

result, the frequency of user conflicts between non-motorized and motorized recreation users would likely 

decrease in the short and long terms.

Compared to the other action alternatives, Alternative 5 would provide the second-largest amount of 

road additions (5.0 miles) to the NFTS, tied with Alternative 2. Alternative 5 would add more miles of 

road than Alternatives 1, 3, 4, and 7, but less than Alternative 6 (see Table 3.07-4). Alternative 5 would 

provide the largest amount of motorized trail (75.4 miles) additions to the NFTS (see Table 3.07-7). These

additions beneficially affect motorized recreation opportunities for a diversity of vehicle classes. All of 

the road additions would be open to all vehicles seasonally, with most of the mileage open May 1 to

December 31 (4.7 miles), but 0.3 miles would be open May 1 to November 1. Most (61.9 miles) of the 

motorized trail additions would be open from May 1 to December 31, with the remaining 13.4 miles open 

April 1 to December 31 and 0.1 miles open May 1 to September 15. Of the total 75.5 miles of trail 
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additions, 44.7 miles would be open to high-clearance 4WD, 4.8 miles would be open to ATVs and 

motorcycles, and 26.0 miles would be open to motorcycles (see Table 3.07-8).

Adding presently unauthorized roads and trails to the NFTS would have a beneficial effect on 

motorized opportunities by providing additional miles of recreation opportunities. The proposed trail 

additions in Alternative 5 contribute to a variety of experiences with easy-to-extremely difficult 

riding/driving experiences, especially for 4WD operators and motorcycle operators (see Table 3.07-8).

The proposed route additions also contribute to the continuity of the motor-touring opportunities by 

reducing dead-end routes, increasing loop and connector opportunities, and providing access to a diversity 

of dispersed recreation activities, providing beneficial effects to motorized recreation opportunities. The 

season of use restrictions on proposed road and trail additions may have a negative effect in the short and 

long terms to motorized opportunities by reducing mileage of motorized opportunity during the closure 

and a beneficial effect to non-motorized opportunities by increasing the acreage available for nonmotorized activities during the closure. As shown in Table 3.07-10, Alternative 5 provides motorized 

access to a total of 188 dispersed recreation sites, of which 183 are associated with an addition to the 

NFTS (see changes to the NFTS, ML 1 additions for the remainder) providing a beneficial effect to 

motorized recreation opportunities. When compared to the other alternatives, Alternative 5 provides the 

third most motorized access to dispersed recreation behind Alternatives 1 and 6.

Indicators referenced:

• Measurement Indicator 2: Non-motorized recreation opportunity 

• Measurement Indicator 3: Motorized recreation opportunity

• Measurement Indicator 4: Type of motorized access to dispersed recreation

• Measurement Indicator 5: Impact of proposed changes to the NFTS on neighboring private and 

federal lands (dust, noise, use conflicts).

Establish motorized “Open Areas.” Alternative 5 does not propose the establishment of any new

“Open Areas” to the NFTS (refer to Table 3.07-9). No direct effects would result, as no change would be 

made from the current management situation. However, a possible indirect effect would be to increase the 

density of users in the existing Prosser Pits OHV “Open Area.” Compared to the other alternatives, 

Alternative 5 would provide fewer acres of “Open Area” opportunities than Alternatives 2 and 6, and an 

equal amount as Alternatives 1, 3, 4, and 7.

Indicators referenced: 

• Measurement Indicator 3: Motorized recreation opportunity

Changes to the existing NFTS [changing the vehicle class, season of use, and reopening ML 1 

roads]. Proposals to change the vehicle class of NFTS routes to provide more mixed use would benefit 

motorized recreation by increasing the diversity of motorized opportunities (and looping opportunities). 

Changes in vehicle class that restrict motor vehicle types on NFTS routes would negatively affect 

motorized recreation diversity. A change in maintenance level through downgrading would increase the 
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diversity of motorized opportunities (and looping opportunities); upgrading the road class would decrease 

the diversity of the motorized opportunities.

Alternative 5 proposes mixed use on about 398.7 miles of NFTS roads (see Table 3.07-5). 

Alternatives 5 and 2 are tied for the largest amount of mixed use. Mixed use on NFTS roads would 

benefit motorized recreation by increasing the diversity of motorized opportunities. The proposed changes 

to the NFTS also contribute to the continuity of the motor-touring opportunities by reducing dead-end 

routes, increasing loop and connector opportunities, and providing access to a diversity of dispersed 

recreation activities for non-highway-legal vehicle operators, providing beneficial effects to motorized 

recreation opportunities. However, the authorization of mixed use on the NFTS could increase the 

likelihood that adjacent private lands would experience increased levels of intrusion by and impacts from 

OHVs, an impact to the affected landowners who may experience high levels of trespass from 

unrestricted OHV use.

Season of use restrictions on existing USFS roads and trails may have a negative effect (short and 

long term) to motorized opportunities by reducing mileage of motorized opportunities during the closure 

and a beneficial effect to non-motorized opportunities by increasing the acreage available for nonmotorized activities during the closure. In Alternative 5, 1,396.7 total miles of route would have changes 

in seasonal restrictions (see Table 3.07-6). Wet weather seasonal restrictions are added to minimize 

erosion and protect water quality, closing motorized opportunities from January 1 to May 31 in the 

Burlington area and January 1 to April 30 on the remainder of the Forest on native surface roads and 

motorized trails. While Alternative 5 includes the most miles of seasonal closure of any alternative (see 

Table 3.07-6), it also includes the lifting of the deer winter range seasonal restrictions from November 1 

to May 1, providing beneficial effects to motorized recreation opportunities in the Management Area 84 

(Humbug-Sailor), through a Forest Plan amendment (see Table 3.07-1, and next section). This lifting of 

these restrictions would be especially beneficial to Sacramento-area riders who would enjoy the Sugar 

Pine area later into the year.

In Alternative 5, 79.3 miles of Maintenance Level 1 would be reopened as open to all vehicles road 

addition to the NFTS (see Table 3.07-4). About 70.3 miles would be reopened for a season of May 1 to 

December 31, 8.7 miles would be reopened from May 1 to November 1, and 0.3 miles would be reopened 

from April 1 to December 31. About 14.0 miles of ML 1 road would be reopened as ATV and motorcycle 

trails seasonally (see Table 3.07-7). In addition 13.9 miles of ATV and motorcycle trail would be reopened

May 1 to December 31, and an additional 0.1 miles of motorcycle trail would be reopened April 1 to 

December 31. The season of use restriction on the proposed reopening of these ML 1 roads to roads and 

motorized trails may have a negative effect in the short and long terms to motorized opportunities by 

reducing mileage of motorized opportunity during the closure and a beneficial effect to non-motorized 

opportunities by increasing the acreage available for non-motorized activities during the closure. 

Alternative 5 reopens a total of 93.4 miles of ML 1 roads (for roads open to all vehicles and for motorized 

trail use), substantially more than any other alternative. Alternative 5 would also provide motorized access 

to 5 additional dispersed sites accessed from reopened ML 1 roads, 3 of those roads would be reopened as 

Open to All Vehicles, another would be reopened as an ATV and motorcycle trail, and another would be 
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open to motorcycles only (see Table 3.07-10). Alternative 5 provides motorized access to the third highest 

number of dispersed sites behind Alternatives 1 and 6.

Indicators referenced:

• Measurement Indicator 2: Non-motorized recreation opportunity 

• Measurement Indicator 3: Motorized recreation opportunity

• Measurement Indicator 4: Type of motorized access to dispersed recreation

• Measurement Indicator 5: Impact of proposed changes to the NFTS on neighboring private and 

federal lands (dust, noise, use conflicts).

Amending the Forest Plan. Adding unauthorized roads and trails to the NFTS would be consistent 

with the ROS as allocated in the LRMP. All routes proposed for addition to the NFTS comply with the 

ROS class in the associated management area. All proposed route additions under this alternative would 

be located in semi-primitive motorized, roaded natural, or rural ROS classes. However, in regard to a 

change in season of use (see previous section), the lifting of the deer winter range seasonal restrictions 

would require a Forest Plan amendment to remove the November 1 to May 1 seasonal closure in the 

Sugar Pine area (Management Area 84, Humbug Sailor)(see Table 3.07-1).

Indicators referenced: 

• Measurement Indicator 1: Consistency with LRMP 

Alternative 6 – Preferred Alternative Motorized Access and Resource Protection

Alternative 6 is the Preferred Alternative. It responds to issues of providing motorized public access and 

recreation opportunities while minimizing impacts to natural resources. Alternative 6 would provide

motorized access to dispersed recreation opportunities (including camping, hunting, fishing, hiking, and 

horseback riding) and a diversity of motorized recreation opportunities (including 4WD Vehicles, 

motorcycles, ATVs, and passenger vehicles). This alternative prohibits cross country travel, adds about 13 

miles of road and 48 miles of motorized trail to the NFTS, establishes 244 acres as motorized “Open 

Areas,” allows 253 miles of mixed use, makes 1,370 miles of changes in season of use, provides for 

motorized access to 437 dispersed sites, and makes one amendment to the Forest Plan.

Prohibition of cross country wheeled motorized vehicle travel. Under Alternative 6, cross country 

motorized vehicle travel would be prohibited. The prohibition of wheeled motor vehicle use off the NFTS 

would have a beneficial effect on non-motorized recreation opportunities and would reduce negative 

impacts to populated areas and neighboring lands of various ownerships in the short and long terms by 

reducing noise, dust and physical presence of motorized vehicles. Prohibiting cross country motorized 

travel would also curtail on-going negative effects to visitors and NFS lands from motorized vehicles 

such as noise, dust and physical presence in the short and long terms. 

Compared to Alternative 1, prohibiting cross country motorized vehicle travel in Alternative 6 would 

result in a net loss of acreage available for cross country motorized recreation, negatively impacting

motorized recreation opportunities. This prohibition of cross country travel will concentrate motorized 
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use on designated roads and trails. The concentration of use resulting from prohibiting cross country 

travel in the action alternatives will outweigh any similar effects produced by differences between the 

action alternatives. This concentration of use is expected to increase the density of riders/drivers per mile 

of route, potentially changing the motorized experience on the Tahoe National Forest. Most OHV 

enthusiasts are expected to continue to return to the areas they currently visit, but will alter their 

expectations (and riding styles) to account for the increased density. Rider/driver adjustments may include 

changing the time or day of visit, adapting a more defensive riding style (slower speeds, more attentive to 

oncoming traffic), and improved riding etiquette (use of hand signals). A small percentage of users may 

be displaced to different areas on the TNF, or adjacent riding areas. The cross country prohibition would 

also reduce motorized access to dispersed recreation activities. However, this alternative has the most 

spur roads to dispersed recreation sites recommended by the public and it establishes three “Open Areas” 

(see “Open Area” effects below). Although motorized recreation opportunities on NFS lands would be 

greatly reduced, other motorized recreation opportunities would be available and the NFTS would be 

increased.

Indicators referenced:

• Measurement Indicator 2: Non-motorized recreation opportunity 

• Measurement Indicator 3: Motorized recreation opportunity

• Measurement Indicator 4: Type of motorized access to dispersed recreation

• Measurement Indicator 5: Impact of proposed changes to the NFTS on neighboring private and 

federal lands (dust, noise, use conflicts).

Adding facilities (presently unauthorized roads and trails) to the NFTS. Adding unauthorized 

roads and trails may have a negative effect (short and long term) on non-motorized opportunities due to 

an increase in noise, dust, physical presence, possible use conflicts and displacement. Under Alternative 6 

about 0.2 percent of the Forest would have additional impacts from the dust, odors, and noise typically 

associated with the proposed route additions. Alternative 6 would also include one road addition that 

would cross the non-motorized Pacific Crest Trail, requiring the installation of vehicle barriers to prevent 

motorized use on the PCT. When compared to the other alternatives, the proposed route additions under 

Alternative 6 would have more impact on the Forest’s “quiet” recreation opportunities than Alternatives 3 

and 4, but less impact than Alternatives 1, 2, 5, and 7 (see Table 3.07-3). Alternative 6 proposes 38.5 

miles of road and trail additions within 1⁄2 mile of neighboring private and federal lands, potentially 

having some noise, dust, and physical presence impacts on neighboring lands. When compared to the 

other alternatives, Alternative 6 would have the second largest percent change on neighboring private and 

federal lands of any alternative behind Alternative 5 (see Table 3.07-11). Production of a motor vehicle 

use map (MVUM) would allow recreationists to better plan recreational pursuits. As a result, the 

frequency of user conflicts between non-motorized and motorized recreation users would likely decrease 

in the short and long terms.

Compared to the other action alternatives, Alternative 6 would add the most miles (13.1 miles) to the 

NFTS of any alternative (see Table 3.07-4). Alternative 6 would provide the third most amount of 
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motorized trail (48.3 miles) additions to the NFTS (see Table 3.07-7). These additions beneficially affect 

motorized recreation opportunities for a diversity of vehicle classes. All of the road additions would be 

Open to All Vehicles seasonally, with a majority of the mileage open May 1 to December 31 (7.5 miles), 

but 5.5 miles would be open April 1 to December 31. More than half (25.5 miles) of the motorized trail 

additions would be open from open April 1 to December 31, with the remaining 22.8 miles open May 1 to 

December 31. Of the total 48.3 miles of trail additions, 22.5 miles would be open to high-clearance 4WD, 

4.8 miles would be open to ATVs and motorcycles, and 20.9 miles would be open to motorcycles (see 

Table 3.07-8).

Adding unauthorized roads and trails to the NFTS would have a beneficial effect on motorized 

opportunities by providing additional miles of recreation opportunities. The proposed trail additions in 

Alternative 6 contribute to a variety of experiences with easy-to-extremely difficult riding/driving 

experiences, especially for 4WD operators and motorcycle riders (see Table 3.07-8). The proposed route 

additions also contribute to the continuity of the motor-touring opportunities by reducing dead-end routes, 

increasing loop and connector opportunities, and providing access to a diversity of dispersed recreation 

activities, providing beneficial effects to motorized recreation opportunities. The season of use restrictions 

on proposed road and trail additions may have a negative effect in the short and long terms to motorized 

opportunities by reducing mileage of motorized opportunity during the closure and a beneficial effect to 

non-motorized opportunities by increasing the acreage available for non-motorized activities during the 

closure. As shown in Table 3.07-10, Alternative 6 provides motorized access to a total of 437 dispersed

recreation sites, of which 432 are associated with an addition to the NFTS (see changes to the NFTS, and 

ML 1 additions for the remainder) providing a beneficial effect to motorized recreation opportunities. 

When compared to the other alternatives, Alternative 6 provides the second most motorized access to 

dispersed recreation of any alternative, behind Alternative 1.

Indicators referenced:

• Measurement Indicator 2: Non-motorized recreation opportunity 

• Measurement Indicator 3: Motorized recreation opportunity

• Measurement Indicator 4: Type of motorized access to dispersed recreation

• Measurement Indicator 5: Impact of proposed changes to the NFTS on neighboring private and 

federal lands (dust, noise, use conflicts).

Establish motorized “Open Areas.” Alternative 6 proposes establishing 3 new motorized “Open 

Areas” totaling 244 acres, allowing cross country motorized travel in the Stampede/Prosser/Boca 

reservoir areas seasonally from May 1 to December 31 (see Table 3.07-9). The establishment of these 

previously unauthorized “Open Areas” may have a negative effect (short and long term) on nonmotorized opportunities due to an increase in noise, dust, physical presence, possible use conflicts and 

displacement. These “Open Areas” within 1⁄2 mile of neighboring private and federal lands, may also 

contribute to this alternative potentially having the fourth greatest noise, dust, and physical presence 

impacts on neighboring lands when compared to the other alternatives (see Table 3.07-3). Because lands 

around the reservoirs are largely managed by the Forest Service, this effect would be minimal. In the 
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690 – Tahoe National Forest

reservoir areas, a likely indirect effect of the “Open Area” establishment would concentrate the 

participation in, and the impact of, numerous non-motorized sports including picnicking, swimming, and 

dog walking around the shoreline adjacent to these established “Open Areas.”

Alternative 6 would limit the “Open Area” opportunities to operators of highway legal vehicles 

including pickups, jeeps, SUVs, and sedans. Compared to the other alternatives, only Alternatives 6 and 2 

provide for additional “Open Area” opportunities. However Alternative 6 is the only one with a seasonal 

“Open Area” to Highway-legal only addition, providing a beneficial effect on motorized recreation 

opportunities with a moderate diversity of vehicle classes and access to dispersed recreation. Just north of 

Truckee, the Boca, Prosser, and Stampede reservoirs would provide 244 acres of motorized opportunity 

along the shoreline, below the high water mark, for camping, boating, and other day-use activities. 

Establishing previously unauthorized “Open Areas” would have a beneficial effect on motorized 

opportunities and would contribute to the variety of motorized experiences found on the TNF. In addition, 

this “Open Area” would serve as a quasi-dispersed site itself, accentuating the 437 dispersed sites 

proposed to be added in this alternative, contributing to Alternative 6 ranking as the second best 

alternative in regard to motorized access to dispersed recreation sites when compared to the other 

alternatives (behind Alternative 1). Alternative 6 would provide the second-most acres of “Open Area” 

opportunities of the action alternatives (behind Alternative 2).

Indicators referenced: 

• Measurement Indicator 2: Non-motorized recreation opportunity 

• Measurement Indicator 3: Motorized recreation opportunity

• Measurement Indicator 4: Type of motorized access to dispersed recreation

• Measurement Indicator 5: Impact of proposed changes to the NFTS on neighboring private and 

federal lands (dust, noise, use conflicts).

Changes to the existing NFTS [changing the vehicle class, season of use, and reopening

ML 1 roads]. Proposals to change the vehicle class of NFTS routes to provide more mixed use would 

benefit motorized recreation by increasing the diversity of motorized opportunities (and looping 

opportunities). Changes in vehicle class that restrict motor vehicle types on NFTS routes would 

negatively affect motorized recreation diversity. A change in maintenance level through downgrading 

would increase the diversity of motorized opportunities (and looping opportunities); upgrading the road 

class would decrease the diversity of the motorized opportunities.

Alternative 6 proposes mixed use on about 252.7 miles of NFTS roads (see Table 3.07-5). 

Alternatives 6 would provide more mixed use than Alternatives 1, 3, 4, and 7, but less than Alternatives 2 

and 5. Mixed use on NFTS roads would benefit motorized recreation by increasing the diversity of 

motorized opportunities. The proposed changes to the NFTS also contribute to the continuity of the 

motor-touring opportunities by reducing dead-end routes, increasing loop and connector opportunities, 

and providing access to a diversity of dispersed recreation activities for non-highway-legal vehicle 

operators, providing beneficial effects to motorized recreation opportunities. However, the authorization 

of mixed use on the NFTS could increase the likelihood that adjacent private lands would experience 
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increased levels of intrusion by and impacts from OHVs, an impact to the affected landowners who may 

experience high levels of trespass from unrestricted OHV use.

Season of use restrictions on existing NFTS roads and trails may have a negative effect (short and 

long term) to motorized opportunities by reducing miles available for motorized opportunities during the 

closure and a beneficial effect to non-motorized opportunities by increasing the acreage available for nonmotorized activities during the closure. In Alternative 6, 1,369.5 total miles of route would have changes 

in seasonal restrictions (see Table 3.07-6). Wet weather seasonal restrictions are added to minimize 

erosion and protect water quality, closing motorized opportunities from January 1 to May 31 in the 

Burlington area and January 1 to April 30 on the remainder of the Forest on native surface roads and 

motorized trails. While Alternative 6 includes the second-largest amount of miles of seasonal closure of 

any alternative (behind Alternative 5), it also includes the lifting of the deer winter range seasonal 

restrictions from November 1 to May 1, providing beneficial effects to motorized recreation opportunities 

in the Management Area 84 (Humbug-Sailor), requiring a Forest Plan amendment (see Table 3.07-1, and 

next section). This lifting of these restrictions would be especially beneficial to Sacramento-area riders 

who would enjoy the Sugar Pine area later into the year. In addition, over the snow travel would be 

permitted on 3.6 miles of the Fordyce Jeep trail when 15 inches of snow is present on the ground.

In Alternative 6, 2.8 miles of Maintenance Level 1 roads would be reopened with an Open to All 

Vehicles status (see Table 3.07-4). About 2.2 miles would be reopened from April 1 to December 31, and 

0.6 miles would be reopened for a season of May 1 to December 31. About 8.6 miles of ML 1 roads

would be reopened as ATV and motorcycle trails seasonally (see Table 3.07-7) and 8.5 miles of ATV and 

motorcycle trail and 0.1 miles of motorcycle trail would be reopened April 1 to December 31. The season 

of use restriction on the proposed reopening of these ML 1 routes may have a negative effect (short and 

long term) to motorized opportunities by reducing mileage of motorized opportunity during the closure 

and a beneficial effect to non-motorized opportunities by increasing the acreage available for nonmotorized activities during the closure. Alternative 6 reopens a total of 11.3 miles of ML 1, substantially 

less than Alternative 5, but substantially more than any of the other alternatives. Alternative 6 would also 

provide motorized access to 5 additional dispersed sites accessed from reopened ML 1 roads, 3 of those 

roads would be reopened as Open to All Vehicles, while another would be reopened as a ATV and 

motorcycle trail, and another would be open to motorcycles only (see Table 3.07-10). When compared to 

the rest of the alternatives, Alternative 6 provides motorized access to the second most number of 

dispersed sites of any alternative, behind Alternative 1.

Indicators referenced:

• Measurement Indicator 2: Non-motorized recreation opportunity 

• Measurement Indicator 3: Motorized recreation opportunity

• Measurement Indicator 4: Type of motorized access to dispersed recreation

• Measurement Indicator 5: Impact of proposed changes to the NFTS on neighboring private and 

federal lands (dust, noise, use conflicts).
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692 – Tahoe National Forest

Amending the Forest Plan. Adding unauthorized roads and trails to the NFTS would be consistent 

with the ROS as allocated in the LRMP. All routes proposed for addition to the NFTS comply with the 

ROS class in the associated management area. All proposed route additions under this alternative would 

be located in semi-primitive motorized, roaded natural, or rural ROS classes. However, in regard to a 

change in season of use (see previous section), the lifting of the deer winter range seasonal restrictions 

would require a Forest Plan amendment to remove the November 1 to May 1 seasonal closure in the 

Sugar Pine area (Management Area 84, Humbug Sailor)(see Table 3.07-1).

Indicators referenced: 

• Measurement Indicator 1: Consistency with LRMP 

Alternative 7 – Proposed Action as identified in the Notice of Intent (NOI)

Alternative 7 is the Proposed Action as published in the Notice of Intent in the Federal Register. This 

alternative prohibits cross country travel, adds 37 miles of motorized trail to the NFTS (but no roads), 

establishes no new acres as motorized “Open Areas,” allows 3 miles of mixed use, makes no changes in 

season of use, and provides for motorized access to 29 dispersed sites. This alternative makes no 

amendments to the Forest Plan.

Prohibition of cross country wheeled motorized vehicle travel. Under Alternative 7, cross country 

motorized vehicle travel would be prohibited. The prohibition of wheeled motor vehicle use off the NFTS 

would have a beneficial effect on non-motorized recreation opportunities and would reduce negative 

impacts to populated areas and neighboring lands of various ownerships in the short and long terms by 

reducing noise, dust and physical presence of motorized vehicles. Prohibiting cross country motorized 

travel would also curtail on-going negative effects to visitors and NFS lands from motorized vehicles 

such as noise, dust and physical presence in the short and long terms.

Compared to Alternative 1, prohibiting cross country motorized vehicle travel in Alternative 7 would 

result in a net loss of acreage available for motorized recreation. Alternative 7 would provide no 

opportunities for cross country motorized travel, resulting in a negative impact on motorized recreation 

opportunities. This prohibition of cross country travel will concentrate motorized use on designated roads 

and trails. The concentration of use resulting from prohibiting cross country travel in the action 

alternatives will outweigh any similar effects produced by differences between the action alternatives.

This concentration of use is expected to increase the density of riders/drivers per mile of route, potentially 

changing the motorized experience on the Tahoe National Forest. Most OHV enthusiasts are expected to 

continue to return to the areas they currently visit, but will alter their expectations (and riding styles) to 

account for the increased density. Rider/driver adjustments may include changing the time or day of visit, 

adapting a more defensive riding style (slower speeds, more attentive to oncoming traffic), and improved 

riding etiquette (use of hand signals). A small percentage of users may be displaced to different areas on 

the TNF, or adjacent riding areas. The cross country prohibition would also reduce motorized access to 

dispersed recreation activities. The loss of available “Open Area” acreage is somewhat offset, however, by 

the proposed addition of motorized routes to the NFTS. Although motorized recreation opportunities on 
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“Open Areas” would not be provided, other motorized recreation opportunities would be available and the 

NFTS would be increased.

Indicators referenced:

• Measurement Indicator 2: Non-motorized recreation opportunity 

• Measurement Indicator 3: Motorized recreation opportunity

• Measurement Indicator 4: Type of motorized access to dispersed recreation

• Measurement Indicator 5: Impact of proposed changes to the NFTS on neighboring private and 

federal lands (dust, noise, use conflicts).

Adding facilities (presently unauthorized roads and trails) to the NFTS. Adding unauthorized 

roads and trails may have a negative effect (short and long term) on non-motorized opportunities due to 

an increase in noise, dust, physical presence, possible use conflicts and displacement. Under Alternative 7 

about 0.3 percent of the Forest would have additional impacts from the dust, odors, and noise associated 

with the proposed route additions. Alternative 7 also adds one road to the NFTS that crosses the nonmotorized Pacific Crest Trail, requiring the installation of vehicle barriers to prevent motorized use on the 

PCT. When compared to the other alternatives, the proposed route additions under Alternative 7 would 

have more impact on the Forest’s “quiet” recreation opportunities than Alternatives 3, 4, and 6, less 

impact than Alternatives 1 and 5, and the same amount of impact as Alternative 2 (see Table 3.07-3). 

Alternative 7 proposes 19.1 miles of trail route additions within 1⁄2 mile of neighboring private and federal

lands, potentially having some noise, dust, and physical presence impacts on neighboring private and 

federal lands. When compared to the other alternatives, Alternative 7 would have the fourth most impact 

on neighboring private and federal lands of any alternative behind Alternatives 1, 5 and 6 (see Table 3.07-

11). Production of a motor vehicle use map (MVUM) would allow recreationists to better plan 

recreational pursuits. As a result, the frequency of user conflicts between non-motorized and motorized 

recreation users would likely decrease in the short and long terms.

Compared to the other alternatives, Alternatives 7, 1, and 3 would provide the least amount of road 

additions (0.0 miles) to the NFTS (see Table 3.07-4). Alternative 7 would provide the fourth highest 

amount of motorized trail (36.6 miles) additions to the NFTS (see Table 3.07-7). These additions 

beneficially affect motorized recreation opportunities for a diversity of vehicle classes. More than half 

(22.6 miles) of the motorized trail additions would be open year-round, with the remaining 14.0 miles 

open May 1 to December 31. Of the total 36.6 miles of trail additions, 16.9 miles would be open to highclearance 4WD, 3.4 miles would be open to ATVs and motorcycles, and 16.4 miles would be open to 

motorcycles (see Table 3.07-8).

Adding unauthorized roads and trails to the NFTS would have a beneficial effect on motorized 

opportunities by providing additional miles of opportunities. The proposed trail additions in Alternative 7 

contribute to a variety of experiences with easy-to-extremely difficult riding/driving experiences, 

especially for 4WD operators and motorcycle riders (see Table 3.07-8). The proposed route additions also 

contribute to the continuity of the motor-touring opportunities by reducing dead-end routes, increasing 

loop and connector opportunities, and providing access to a diversity of dispersed recreation activities, 
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694 – Tahoe National Forest

providing beneficial effects to motorized recreation opportunities. The season of use restrictions on 

proposed trail additions may have a negative effect in the short and long terms to motorized opportunities 

by reducing mileage of motorized opportunity during the closure and a beneficial effect to non-motorized 

opportunities by increasing the acreage available for non-motorized activities during the closure. As 

shown in Table 3.07-10, Alternative 7 provides motorized access to a total of 29 dispersed recreation sites, 

of which 27 are associated with an addition to the NFTS and 2 are associated with reopening of ML 1

roads. These routes and associated dispersed recreation sites provide a beneficial effect to motorized 

recreation opportunities. When compared to the other alternatives, Alternative 7 provides the second 

smallest amount of motorized access to dispersed recreation of any alternative, behind Alternative 3.

Indicators referenced:

• Measurement Indicator 2: Non-motorized recreation opportunity 

• Measurement Indicator 3: Motorized recreation opportunity

• Measurement Indicator 4: Type of motorized access to dispersed recreation

• Measurement Indicator 5: Impact of proposed changes to the NFTS on neighboring private and 

federal lands (dust, noise, use conflicts).

Establish motorized “Open Areas.” Alternative 7 does not establish any new “Open Areas” (refer to 

Table 3.07-9). No direct effects would result, as no change would be made from the current management 

situation. However, a possible indirect effect would be to increase the density of users in the existing 

Prosser Pits OHV “Open Area.” Compared to the other alternatives, Alternative 7 would provide fewer 

acres of “Open Area” opportunities than Alternatives 2 and 6, and an equal amount as Alternatives 1, 3, 4, 

and 5.

Indicators referenced: 

• Measurement Indicator 3: Motorized recreation opportunity 

Changes to the existing NFTS [changing the vehicle class, season of use,

and reopening ML 1 roads]. Proposals to change the vehicle class of NFTS routes to provide more 

mixed use would benefit motorized recreation by increasing the diversity of motorized opportunities (and 

looping opportunities). Changes in vehicle class that restrict motor vehicle types on NFTS routes would 

negatively affect motorized recreation diversity. A change in maintenance level through downgrading 

would increase the diversity of motorized opportunities (and looping opportunities); upgrading the road 

class would decrease the diversity of the motorized opportunities.

Alternative 7 proposes mixed use on about 3.4 miles of NFTS roads (see Table 3.07-5). Alternatives 7 

and 4 are tied for the third most mixed use of any alternative. Mixed use on NFTS roads would benefit 

motorized recreation by increasing the diversity of motorized opportunities. The proposed changes to the 

NFTS also contribute to the continuity of the motor-touring opportunities by reducing dead-end routes, 

increasing loop and connector opportunities, and providing access to a diversity of dispersed recreation 

activities for non-highway-legal vehicle operators, providing beneficial effects to motorized recreation 
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opportunities. However, the authorization of mixed use on the NFTS could increase the likelihood that 

adjacent private lands would experience increased levels of intrusion by and impacts from OHVs, an 

impact to the affected landowners who may experience high levels of trespass from unrestricted OHV 

use. Although Alternative 7 provides less motorized recreation opportunity through mixed use when 

compared to Alternatives 2, 5, and 6, it provides more motorized recreation opportunity on existing NFTS 

roads through mixed use when compared to Alternatives 1 and 3, and equal to Alternative 4.

No changes to the NFTS in regard to season of use would be made under Alternative 7. No direct or 

indirect effects from changes to the season of use would result, as no change would be made from the 

current management situation.

In Alternative 7, 0.9 miles of Maintenance Level 1 would be reopened year-round as a road addition 

to the NFTS with an Open to All Vehicles status (see Table 3.07-4). About 0.1 miles of ML 1 road would 

be reopened year-round as a motorcycle trail (see Table 3.07-7). Alternative 7 reopens a total of 1.0 mile 

of ML 1 roads, which is less than Alternatives 5 and 6, but more than Alternatives 1, 2, 3 and 4. 

Alternative 7 would also provide motorized access to 2 additional dispersed sites accessed from reopened 

ML 1 roads, one of those roads would be reopened as Open to All Vehicles, and the other would be open 

to motorcycles only (see Table 3.07-10). When compared to the rest of the alternatives, Alternative 7 

provides motorized access to the second lowest number of dispersed sites of any alternative; only 

Alternative 3 would provide fewer.

Indicators referenced:

• Measurement Indicator 2: Non-motorized recreation opportunity 

• Measurement Indicator 3: Motorized recreation opportunity

• Measurement Indicator 4: Type of motorized access to dispersed recreation

• Measurement Indicator 5: Impact of proposed changes to the NFTS on neighboring private and 

federal lands (dust, noise, use conflicts).

Amending the Forest Plan. No changes to the Forest Plan would be made under Alternative 7. No 

direct or indirect effect would result, as no change would be made from the current management situation.

Indicators referenced: 

• Measurement Indicator 1: Consistency with LRMP

Cumulative Effects

The cumulative effects analysis for recreation considers the impact of the alternatives when combined 

with past, present, and foreseeable future actions and events. The spatial boundary (Forest-wide) of the 

cumulative effects analysis was selected because impacts to the recreation system in one area of the 

Forest can affect the continuity of the system and public access opportunities in other parts of the Forest. 

The temporal scope of 20 years was selected because impacts to recreation and public access from present 

and reasonably foreseeable future activities may occur over this timeframe. In analyzing cumulative 

effects of Motorized Travel Management, the TNF considered effects from all present and reasonably 
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foreseeable future actions that have the potential for affecting motorized and non-motorized recreation 

opportunities. The actions affecting the recreation resource include road and trail construction, rerouting 

trails, restoring unauthorized routes, reclaiming road spurs, and decommissioning roads. For a full list of 

the present and reasonably foreseeable future actions considered in this analysis, see Appendix H

(Reasonably Foreseeable Projects and Cumulative Effects). Projects with the most likely potential for 

affecting motorized and non-motorized opportunities are listed below in Table 3.07-14.

The changes associated with these projects have been incorporated into the recreation opportunity by 

alternative listed in Table 3.07-15. It is anticipated that the effects of the present and reasonably 

foreseeable future actions would meet ROS classifications for the management area in which they occur. 

The past activities, including the existing NFTS, have shaped the recreation opportunities and ROS 

settings available on the Forest. The effects of the present and reasonably foreseeable future activities 

listed in Table 3.07-14 would continue to shape the recreation opportunities and ROS settings available on 

the Forest.

Table 3.07-14. Reasonably foreseeable projects with possible cumulative effects to recreation

Project Description

Hawley and Fordyce Meadows Rehab 

Project

Reroute 3⁄4 mile of existing trail in Hawley Mdw, reroute 1⁄2 mile existing 

trail on Fordyce Jeep Trail.

Reclamation of Abandoned Mine 

Features at the Dredge and Eaglebird 

Mines

Remediate public safety hazards, reclaim degraded slopes and road 

spurs, and remove abandoned equipment.

Canyon Forest Health Reduce fuels, thin forest stands, decommission roads.

Stockrest Springs Restoration Restore floodplain function and reroute a trail in Stockrest Springs 

Watershed.

Little Truckee Wildlife Habitat 

Improvement project

Improve sensitive nesting, stream and riparian habitats and water 

quality by obliterating and restoring two illegal trails/hill climbs that run 

perpendicular to the Little Truckee River.

Legacy Trail Construct non-motorized multiple use trail from private land in the town 

of Truckee to Glenshire subdivision.

South Lincoln Creek Coop road 

segment Construct 1200’ of road to the Sierra Pacific property line.

Little Truckee River Trail Construct about 1 miles of multiple use trail between Highway 89 north 

and FS road #450-10-20 – connect to Upper Little Truckee River 

campground.

Brumby Mechanically thin 530 acres, group select 30 acres, remove conifers 

from 3 acres of aspen, construct 1.3 miles of new permanent road, and 

about 1 mile of temporary road. 

Decreased access to recreation opportunities and increased dust, noise and physical presence of 

motorized machinery may occur during road reconstruction activities (short term impacts). Road 

decommissioning would benefit non-motorized opportunities by eliminating noise, dust, and physical 

presence of motorized vehicles on neighboring private and federal lands and wilderness areas when 

located within 1⁄2 mile from these areas, but may negatively affect motorized recreation by decreasing the 

mileage available for motorized recreation opportunities. Road decommissioning may also increase the 
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amount of forest available for “quiet” recreation opportunities. In the present and reasonably foreseeable 

future, about 125.7 miles of currently open NFTS roads would be decommissioned.

Measurement indicators 1, 2, 3, 4, and 5 were used in the cumulative effects analysis. Measurement 

indicator 1 looked at the impact of proposed changes to the NFTS on the TNF Forest Plan in regard to the 

Recreation Opportunity Spectrum and season of use. No ROS plan amendments would be needed for any 

alternatives because all routes proposed for addition to the NFTS comply with the ROS class in the 

associated management area. No proposed route additions in the action alternatives would be located in 

primitive or semi-primitive non-motorized ROS classes. All proposed route additions would be located in 

semi-primitive motorized, roaded natural, or rural ROS classes. All action alternatives would be 

consistent with ROS. Therefore, no cumulative effects on ROS are anticipated for the action alternatives. 

For potential cumulative effects on ROS for the No Action Alternative, see the cumulative effects section 

for the No Action Alternative, Alternative 1, below. Season of use plan amendments would be required in 

Alternatives 2, 5, and 6 to lift the seasonal deer winter range restrictions in Management Area 84, 

Humbug Sailor (see Table 3.07-1). This removal of the existing November 1 to May 1 seasonal closure 

would extend the riding season in the Sugar Pine area, an increase in motorized opportunities. The 

cumulative effects of these proposed plan amendments may have impacts to both motorized or nonmotorized recreation opportunities, and are taken into account in summary Tables 3.07-15, 16, and 17 and 

the discussion of the four other recreation measurement indicators.

Measurement indicator 2 looks at the impact of proposed changes to the NFTS on non-motorized 

recreation (dust, noise, use conflicts). It also addresses the “quiet” recreation issue. Quiet recreation is 

defined by measurement indicator 2 as the acres outside 1⁄2 mile of an area where motorized use is 

allowed. For cumulative effects analysis, quiet recreation acreage for the No Action Alternative was 

determined using the existing NFTS, other state, county, or private roads traveling through the Forest, and 

the currently identified unauthorized routes. Quiet recreation acreage for the action alternatives was 

determined using the existing NFTS, other state, county, or private roads traveling through the Forest, and 

any proposed route and area additions. See Table 3.07-3 for a full comparison of alternatives regarding 

this indicator. 

Measurement indicator 3 looks at the impact of proposed changes to the NFTS to motorized 

recreation opportunities by alternative by analyzing roads, motorized trails, and “Open Areas” added to 

the NFTS. This indicator includes any effects associated with existing or proposed direction in regard to 

mixed use, maintenance levels, season of use, and reopening ML 1 roads to motorized use. The total 

motorized mileage in an alternative includes proposed route additions and motorized NFTS routes, 

including operational ML 2-5 and all motorized trails. See Tables 3.07-4 through 9 and Table 3.07-15 for 

a full comparison of alternatives regarding this indicator. 
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Table 3.07-15. Motorized Recreation Opportunities Cumulative Effects – Recreation Measurement Indicator 3

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

NFTS Roads Year round 1395.4 1409.6 1395.4 348.1 274.0 234.8 1396.3

Seasonally 672.2 662.9 672.9 1723.2 1878.0 1848.6 672.2

NFTS Trails Year round 265.7 301.0 265.7 0.0 0.0 0.0 288.5

Seasonally 62.5 81.7 62.5 350.9 417.6 385.1 76.5

State, County or other 

jurisdiction roads

Year round 868.2 868.2 868.2 868.2 868.2 868.2 868.2

Private Roads Year round 1,816.5 1,816.5 1,816.5 1,816.5 1,816.5 1,816.5 1,816.5

Unauthorized routes & 

closed NFTS roads 

receiving public 

motorized use

Year round 1698.3 0 0 0 0 0 0

Total Year round 6044.1 4395.3 4345.8 3032.8 2958.7 2919.5 4369.5

Seasonally 734.7 744.6 735.4 2074.1 2295.6 2233.7 748.7

Grand Total 6778.8 5139.9 5081.2 5106.9 5254.3 5153.2 5118.2

Measurement indicator 4 looked at the impact of proposed changes to the NFTS to motorized access 

to dispersed recreation opportunities by alternative by analyzing the type of access and the number of 

dispersed sites accessed as a result of the additions identified in Measurement indicator 3. See Table 3.07-

10 for a full comparison of alternatives regarding this indicator. 

Measurement indicator 5 looks at the impact of proposed changes to the NFTS on neighboring private 

and federal lands by alternative by analyzing the number of miles that occur within 1⁄2 mile of neighboring 

lands. For Alternative 1, routes considered were open roads on the existing NFTS and inventoried 

unauthorized routes. For the action alternatives routes considered were open roads on the existing NFTS 

and any proposed route and area additions. See Table 3.07-11 for a full comparison of alternatives 

regarding this indicator. 

The identified present and reasonably foreseeable future actions were used to determine the 

cumulative effect on NFTS roads open to motorized recreation opportunities. NFTS roads considered 

open to motorized travel include MLs 2 through 5. The cumulative effects analysis includes the direct and 

indirect effects of the five management actions discussed in the environmental consequences section: (1) 

the prohibition of cross country motorized travel, (2) additions of currently unauthorized routes to the 

NFTS, (3) establishment of motorized “Open Areas,” (4) changes to the existing NFTS, and (5) 

amendments to the Forest Plan.

Alternative 1 – No Action

Unrestricted cross country motorized travel under Alternative 1 has the potential to create resource issues 

in the future and a proliferation of user created dead-end routes that may reduce the quality of the 

motorized recreation experience. 

Although consistent with LRMP guidance for ROS, cross country motorized travel may affect ROS 

class settings. Motorized use could inadvertently spread to non-motorized areas, changing areas with non-
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motorized ROS class settings, such as semi-primitive non-motorized, to ROS classes with motorized 

settings such as semi-primitive motorized, roaded natural, or rural. 

Alternative 1 has the greatest potential to negatively alter non-motorized recreation settings, but it is 

difficult to predict where future cross country motorized use would occur. Dust, noise, and motorized 

vehicle presence may impact non-motorized recreationists seeking a “quiet” recreation experience. 

Cumulatively under this alternative, 87.7 percent of the TNF would be affected by motorized use and 

would not be available for “quiet” recreation, the greatest amount of all the alternatives (see Table 3.07-

3). This alternative also has the greatest impact on neighboring private and federal lands and wilderness 

areas, as determined using measurement indicator 5, with about 2,317 miles of NFTS open roads and 

unauthorized motorized routes occurring within 1⁄2 mile of neighboring private and federal lands (see 

Table 3.07-11), the highest amount when compared to all the alternatives. Overall, Alternative 1 has the 

highest potential cumulative impact on non-motorized recreation opportunities and neighboring Federal

and private lands and wilderness areas. 

With no proposed additions or changes to the use of existing NFTS roads or trails and no prohibition 

of cross country motorized travel, Alternative 1 results in no change to the existing motorized recreation 

opportunities. Under Alternative 1, at least 6,779 miles of motorized route (including the unauthorized 

routes) would be available to the public, the most of any alternative (see Table 3.07-15). Without 

prohibition of cross country motorized travel, Alternative 1 provides the greatest access to dispersed 

recreation of any alternative. Since there are no direct or indirect effects to motorized recreation and no 

change from the current management situation, no cumulative effects to motorized recreation would 

result. Overall, Alternative 1 would provide the greatest amount of motorized opportunity.

Alternative 2 – Increased Motorized Recreation and Access Opportunities 

Alternative 2 has the potential to negatively alter non-motorized recreation settings when considering the 

proposed route additions, the existing NFTS, and other roads traveling through the Forest. Dust, noise, 

and motorized vehicle presence may impact non-motorized recreationists seeking a “quiet” recreation 

experience. Cumulatively under this alternative, 83.4 percent of the TNF would be affected by motorized 

use and would not be available for “quiet” recreation, less than the No Action Alternative and Alternative 

5, but more than Alternatives 3, 4, and 6, and about equal to Alternative 7 (see Table 3.07-3). This 

alternative, combined with the past, present and reasonably foreseeable future actions, also has the 

potential to impact neighboring private and federal lands and wilderness areas. About 1,418 miles of 

NFTS open roads and proposed route additions would occur within 1⁄2 mile of neighboring private and 

federal lands and wilderness areas, more than Alternatives 3, 4, and 7, about equal to Alternative 6, but 

less than Alternatives 1 and 5 (see Table 3.07-11). The proposed route additions would add about two 

percent to the number of NFTS route miles occurring within 1⁄2 mile of neighboring private and federal 

lands. Overall, Alternative 2 would provide more beneficial cumulative effects to non-motorized 

recreation than the Alternatives 1 and 5, but less than the rest of the alternatives.

Alternative 2 would have beneficial cumulative effects to motorized recreation by increasing NFTS 

mileage available for motorized recreation. Proposed route additions contribute to a variety of riding 
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experiences as well as the continuity of the motor-touring opportunities. The route additions also provide 

loops, connectors, and access to a diversity of dispersed recreation activities which can benefit both 

motorized and non-motorized recreation opportunities by providing access to trailheads, dispersed 

campsites etc. As shown in Table 3.07-15, proposed road and trail additions and open NFTS roads would 

provide about 5,139.9 miles of motorized recreation opportunity. This alternative also establish 4 

additional motorized “Open Areas” totaling 2,649 acres, providing positive direct, indirect and cumulative 

impacts to motorized recreation opportunities (see Table 3.07-9). Compared to the other alternatives, 

Alternative 2 provides fewer miles of opportunity than Alternatives 1 and 5, more than Alternatives 3, 4,

and 7, and about the same as Alternative 6 (see Table 3.07-15). Alternative 2 would provide motorized 

access to a total of 182 dispersed recreation sites, providing a beneficial effect to motorized recreation 

opportunities. This alternative would provide the fourth most motorized access to dispersed recreation 

sites when compared to the other alternatives, behind Alternatives 1, 5 and 6 (see Table 3.07-10). Overall, 

compared to the other alternatives, Alternative 2 would provide more beneficial cumulative effects to 

motorized recreation than Alternatives 3, 4, and 7, and less than Alternatives 1, 5, and 6.

Alternative 3 – Cross Country Travel Prohibition Only –No Changes to the Existing NFTS

Alternative 3 has the potential to alter non-motorized recreation settings. Dust, noise, and motorized 

vehicle presence may impact non-motorized recreationists seeking a “quiet” recreation experience. 

Cumulatively under this alternative, 83.1 percent of the TNF would be affected by motorized use and 

would not be available for “quiet” recreation, less than any other alternative (see Table 3.07-3). This 

alternative, combined with the past, present and reasonably foreseeable future actions, also has the 

potential to impact neighboring private and federal lands and wilderness areas. About 1,384 miles of 

NFTS open roads occur within 1⁄2 mile of neighboring private and federal lands and wilderness areas, the 

fewest of any alternative (see Table 3.07-11). As this alternative proposes no new additions or changes to 

the existing NFTS, there is no increase from the current condition of open NFTS roads occurring within 

1⁄2 mile of neighboring private and federal lands and wilderness areas. Overall, Alternative 3 would 

provide more beneficial cumulative effects to non-motorized recreation opportunities than any alternative, 

although Alternative 4 is quite similar. 

Alternative 3 NFTS roads would provide about 5,081.2 miles of motorized recreation opportunity. No 

establishment of additional motorized “Open Areas” would be made under this alternative (see Table 

3.07-9). Since there are no new “Open Areas” established (no change from the current management 

situation), there would be no direct, indirect, or cumulative effects to motorized recreation. Compared to 

the other alternatives, Alternative 3 would provide fewer miles of opportunities than any alternative (see 

Table 3.07-15). Alternative 3 would provide motorized access to no additional dispersed recreation sites 

(the least of any alternative), providing no beneficial effect to motorized recreation opportunities (see 

Table 3.07-10). Overall, Alternative 3 would provide the fewest miles of motorized opportunity, and it 

would not provide for motorized access to any additional dispersed sites beyond the existing condition.
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Alternative 4 – Increased Resource Protection

Alternative 4 has the potential to alter non-motorized recreation settings when considering the proposed 

route additions, the existing NFTS, and other roads traveling through the Forest. Dust, noise, and 

motorized vehicle presence may impact non-motorized recreationists seeking a “quiet” recreation 

experience. Cumulatively under this alternative, 83.2 percent of the Tahoe NF would be affected by 

motorized use and would not be available for “quiet” recreation, less than any other alternative except 

Alternative 3 (see Table 3.07-3). Alternative 4, combined with the past, present and reasonably 

foreseeable future actions, also has the potential to impact neighboring private and federal lands and 

wilderness areas. About 1,398 miles of NFTS open roads and proposed route additions would occur 

within 1⁄2 mile of neighboring private and federal lands and wilderness areas, more than Alternative 3, 

about equal to Alternative 7, but less than rest of the alternatives (see Table 3.07-11). The proposed route 

additions would add about a one percent to the amount of open NFTS route miles occurring within 1⁄2 mile 

of neighboring private and federal lands. Overall, Alternative 4 would provide more beneficial cumulative 

effects to non-motorized recreation than any other alternative except Alternative 3, which has about the 

same amount.

Alternative 4 would have moderate beneficial cumulative effects to motorized recreation by 

increasing NFTS mileage available for motorized recreation. Proposed route additions contribute to a 

variety of riding experiences as well as the continuity of the motor-touring opportunities. The route 

additions also provide loops, connectors, and access to a diversity of dispersed recreation activities which 

can benefit both motorized and non-motorized recreation opportunities by providing access to trailheads, 

dispersed campsites etc. Proposed road additions and existing open NFTS roads would provide about 

5106.9 miles of motorized recreation opportunity. No changes to the NFTS in regards to the establishment

of motorized “Open Areas” would be made under this alternative (see Table 3.07-9). Since there are no 

new “Open Areas” established (no change from the current management situation), there would be no 

direct, indirect, or cumulative effects to motorized recreation. Compared to the other alternatives, 

Alternative 4 would provide the second least number of miles of any alternative (see Table 3.07-15), only 

Alternative 3 would provide fewer. Alternative 4 would provide motorized access to a total of 107 

dispersed recreation sites, providing a beneficial effect to motorized recreation opportunities. This 

alternative would provide the third most limited motorized access to dispersed recreation sites when 

compared to the other action alternatives, only Alternatives 3 and 7 would provide fewer (see Table 3.07-

10). Compared to the other alternatives, overall, Alternative 4 ties with Alternative 7 for the second-least 

potential beneficial cumulative impact on motorized users, only Alternative 3 provides less.

Alternative 5 – Increased Motorized Recreation Access

plus Reopening Maintenance Level 1 and Temporary Roads 

Alternative 5 has the potential to negatively alter non-motorized recreation settings when considering the 

proposed route additions, the existing NFTS, and other roads traveling through the Forest. Dust, noise, 

and motorized vehicle presence may impact non-motorized recreationists seeking a “quiet” recreation 

experience. Cumulatively under this alternative, 83.9 percent of the TNF would be affected by motorized 
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use and would not be available for “quiet” recreation, more than any other alternative, except the no

action (see Table 3.07-3). This alternative, combined with the past, present and reasonably foreseeable 

future actions, also has the potential to impact neighboring private and federal lands and wilderness areas. 

About 1,447 miles of NFTS open roads and proposed route additions would occur within 1⁄2 mile of 

neighboring private and federal lands and wilderness areas, more than any alternative except the no-action 

alternative (including unauthorized routes) (see Table 3.07-11). The proposed route additions would 

provide for a four percent increase in the number of open NFTS route miles occurring within 1⁄2 mile of 

neighboring private and federal lands. Overall, when compared to the other action alternatives, 

Alternative 5 would provide more beneficial cumulative effects to non-motorized recreation than 

Alternative 1, but less than any of the rest of the alternatives. 

Alternative 5 would have moderate beneficial cumulative effects to motorized recreation by 

increasing NFTS mileage available for motorized recreation. Proposed route additions contribute to a 

variety of riding experiences as well as the continuity of the motor-touring opportunities. The route 

additions also provide loops, connectors, and access to a diversity of dispersed recreation activities which 

can benefit both motorized and non-motorized recreation opportunities by providing access to trailheads, 

dispersed campsites etc. Proposed road additions and open NFTS roads would provide about 5,254.3 

miles of motorized recreation opportunity. No additional motorized “Open Areas” would be established 

under this alternative (see Table 3.07-9). Since there are no new “Open Areas” established (no change 

from the current management situation), there would be no direct, indirect, or cumulative effects to 

motorized recreation. Compared to the other action alternatives, Alternative 5 would provide the second 

most number of miles of any alternative; only Alternative 1 would provide more (see Table 3.07-15).

Alternative 5 would provide motorized access to a total of 188 dispersed recreation sites, providing a 

beneficial effect to motorized recreation opportunities. This alternative would provide the third most 

motorized access to dispersed recreation sites when compared to the other alternatives, only Alternatives 

1 and 6 would provide more (see Table 3.07-10). Overall, compared to the other alternatives, Alternative 

5 has more potential beneficial cumulative impact on motorized users than Alternatives 2, 3, 4, and 7, less 

than Alternative 1, and about equal potential as Alternative 6.

Alternative 6 – Preferred Alternative Motorized Access and Resource Protection 

Alternative 6 has the potential to negatively alter non-motorized recreation settings through the use of

proposed route additions, the existing NFTS, and other roads traveling through the Forest. Dust, noise, 

and motorized vehicle presence may impact non-motorized recreationists seeking a “quiet” recreation 

experience. Cumulatively under this alternative, 83.3 percent of the TNF would be affected by motorized 

use and would not be available for “quiet” recreation, more than Alternatives 3 and 4, but less than 

Alternatives 1, 2, 5, and 7 when compared to the other action alternatives (see Table 3.07-3). This 

alternative, combined with the past, present and reasonably foreseeable future actions, also has the 

potential to impact neighboring private and federal lands and wilderness areas. About 1,422 miles of 

NFTS open roads and proposed route additions would occur within 1⁄2 mile of neighboring private and 

federal lands and wilderness areas, which is more than Alternatives 3, 4, and 7, about equal to Alternative 
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2, but less than Alternatives 1 and 5 (see Table 3.07-11). The proposed route additions would provide for a 

three percent increase in the number of open NFTS route miles occurring within 1⁄2 mile of neighboring 

private and federal lands. Overall, Alternative 6 would provide more beneficial cumulative effects to nonmotorized recreation than Alternatives 1, 2, and 5, less than Alternatives 3 and 4, and about an equal 

amount of beneficial effect as Alternative 7.

Alternative 6 would have moderate beneficial cumulative effects to motorized recreation by 

increasing NFTS mileage available for motorized recreation. Proposed route additions contribute to a 

variety of riding experiences as well as the continuity of the motor-touring opportunities. The route 

additions also provide loops, connectors, and access to a diversity of dispersed recreation activities which 

can benefit both motorized and non-motorized recreation opportunities by providing access to trailheads, 

dispersed campsites etc. Proposed road additions and open NFTS roads would provide about 5,153.2 

miles of motorized recreation opportunity. This alternative also establishes 3 new motorized “Open 

Areas” totaling 244 acres, providing positive direct, indirect and cumulative impacts to motorized 

recreation opportunities (see Table 3.07-9). Compared to the other alternatives, Alternative 6 would 

provide the third most number of miles than any alternative, behind Alternatives 1 and 5 (see Table 3.07-

15). Alternative 6 would provide motorized access to a total of 437 dispersed recreation sites, providing a 

substantial beneficial effect to motorized recreation opportunities. This alternative would provide the most 

motorized access to dispersed recreation sites behind Alternative 1 (see Table 3.07-10). Overall, compared 

to the other alternatives, Alternative 6 provides more potential beneficial cumulative impacts to motorized 

users than Alternatives 2, 3, 4, and 7, less than Alternative 1, and about equal potential as Alternative 5.

Alternative 7 – Proposed Action as identified in the Notice of Intent (NOI)

Alternative 7 has the potential to negatively alter non-motorized recreation settings through the use of 

proposed route additions, the existing NFTS, and other roads traveling through the Forest. Dust, noise, 

and motorized vehicle presence may impact non-motorized recreationists seeking a “quiet” recreation 

experience. Cumulatively under this alternative, 83.4 percent of the TNF would be affected by motorized 

use and would not be available for “quiet” recreation, which is more than Alternatives 3 and 4, but less 

than Alternatives 1, 5, and 6, and about equal to Alternative 2 when compared to the other alternatives 

(see Table 3.07-3). This alternative, combined with the past, present and reasonably foreseeable future 

actions, also has the potential to impact neighboring private and federal lands and wilderness areas. About 

1,403 miles of NFTS open roads and proposed route additions would occur within 1⁄2 mile of neighboring 

private and federal lands and wilderness areas, more than Alternative 3, about equal to Alternative 4, but 

less than rest of the alternatives (see Table 3.07-11). The proposed route additions would provide for a one 

percent increase in the number of open NFTS route miles occurring within 1⁄2 mile of neighboring private 

and federal lands. Overall, Alternative 7 would provide more beneficial cumulative effects to nonmotorized recreation than Alternatives 1, 2, and 5, less than Alternatives 3 and 4, and about an equal 

amount of beneficial effect as Alternative 6.

Alternative 7 would have moderate beneficial cumulative effects to motorized recreation by 

increasing NFTS mileage available for motorized recreation. Proposed route additions contribute to a 
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variety of riding experiences as well as the continuity of the motor-touring opportunities. The route 

additions also provide loops, connectors, and access to a diversity of dispersed recreation activities which 

can benefit both motorized and non-motorized recreation opportunities by providing access to trailheads, 

dispersed campsites etc. Proposed road additions and open NFTS roads would provide about 5118.2 miles 

of motorized recreation opportunity. No additional “Open Areas” would be established under this 

alternative (see Table 3.07-9). Since there are no new “Open Areas” established (no change from the 

current management situation), there would be no direct, indirect, or cumulative effects to motorized 

recreation. Compared to the other action alternatives, Alternative 7 would provide the third least number 

of miles of any alternative, only Alternatives 3 and 4 would provide fewer (see Table 3.07-15). Alternative 

7 would provide motorized access to a total of 29 dispersed recreation sites, providing a beneficial effect 

to motorized recreation opportunities. Compared to the other alternatives, this alternative would provide 

the second least motorized access to dispersed recreation sites, only better than Alternative 3 (see Table 

3.07-10). Overall, compared to the other alternatives, Alternative 7 holds more potential beneficial 

cumulative impact on motorized users than Alternative 3, about equal potential as Alternative 4, and less 

than the rest of the alternatives.

Compliance with the Forest Plan and Other Direction

Tahoe NF Land and Resource Management Plan

Alternative 1 implements the TNF LRMP, which allows cross country motorized travel on most land 

allocations. However, the LRMP, as written, is not in compliance with the Travel Management Rule. No 

motor vehicle use map would be produced. 

No ROS plan amendments would be needed for any alternatives because all routes proposed for 

addition to the NFTS comply with the ROS class in the associated management area. No proposed route 

additions in the action alternatives would be located in primitive or semi-primitive non-motorized ROS 

classes. All proposed route additions would be located in semi-primitive motorized, roaded natural, or 

rural ROS classes. 

Alternatives 2, 5, and 6 would require a Forest Plan amendment to lift the seasonal deer winter range 

restrictions in Management Area 84, Humbug Sailor. Alternative 2 increases the duration of all motorized 

activity on ML 2 native surface roads and trails in MA 84 by seven months. Alternatives 5 and 6 increase 

the duration of use by two and three months respectively since these areas are also limited by wet weather 

restrictions. The action alternatives comply with all other Forest Plan standards and guidelines, as well as 

any state or Federal regulatory direction identified in the regulatory framework section.

Visual Resources _______________________________________

Introduction

This section of the Motorized Travel Management EIS examines the extent to which alternatives respond 

to visual resources management direction established in the TNF Land and Resource Management Plan 
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Tahoe National Forest – 705

(LRMP) and the Travel Management (TM) Rule. The LRMP visual resources direction was established 

under the implementing regulations of the National Forest Management Act (NFMA).

During development of the Tahoe National Forest’s LRMP, the Forest’s visual resources were 

inventoried to determine the landscape’s scenic attractiveness (variety class inventory) and the public’s 

visual expectations (sensitivity level inventory). Based upon these inventories, visual quality objectives 

(VQOs) were established for all Forest land areas. The VQOs establish minimum acceptable thresholds 

for landscape alterations from an otherwise natural-appearing forest landscape. For example, areas with a 

retention VQO are expected to retain a natural appearance; areas with a partial retention VQO may have 

some alterations, but they remain subordinate to the characteristic landscape; areas with a modification 

VQO can have alterations that do not look natural appearing.

Roads and trails create linear alterations in landscapes that can be mitigated through sound design. 

Unmitigated, they present uncharacteristic line qualities in forest landscapes. Landscapes with a dense 

canopy cover have the capability of masking these linear alterations; sparsely covered landscapes have 

less capability. The proliferation of unauthorized routes, particularly in sparsely covered landscapes, can 

adversely affect the Forest’s visual resources.

Analysis Framework: Statute, Regulation, Forest Plan,

and Other Direction

Direction relevant to the proposed action as it affects visual resources includes:

National Forest Management Act: The NFMA, and its implementing regulations, required the 

inventory and evaluation of the Forest’s visual resource, addressing the landscape’s visual attractiveness 

and the public’s visual expectations. Management prescriptions for definitive lands areas of the forest are 

to include visual quality objectives. 

Travel Management Rule: The TM Rule does not cite aesthetics specifically, but in the designation 

of trails or areas, the responsible official shall consider effects on forest resources, with the objective of 

minimizing effects of motor vehicle use. 

Tahoe NF LRMP: The LRMP contains direction for visual resource management. On page V-7 , the 

LRMP states: Maintain visual quality at the VQO level specified in each management area, as a 

minimum, but maintain higher visual quality wherever practical and compatible with other goals. The 

TNF LRMP also contains specific management area direction for visual resources. For the full list of 

Forestwide standards and guidelines for visual resource management, see the LRMP, page V-24 and V-25. 

In addition to the above forestwide standards and guidelines, each management area is assigned a 

VQO or a range of VQOs to guide decisions and resource management activities. The Forest VQO map, 

shown in the following figure, was used in the effects analysis for this project. See the LRMP for 

standards and guidelines specific to each management area. Refer to Figure 3.07-1 for a map of the VQOs 

of the area.
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706 – Tahoe National Forest

Figure 3.07-1. Tahoe National Forest Visual Quality Objectives
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Effects Analysis Methodology

This analysis was completed using the framework outlined in USDA Forest Service Handbook: The 

Visual Management System (USDA Forest Service, 1974). Non-characteristic line quality created by trail 

routes is the greatest impact to the visual resources from the proposed alternatives. Roads and trails can 

create changes to a naturally appearing landscape by introducing noticeable deviations to the 

characteristic form, line, color or texture of a landscape. The location and design of these routes can 

significantly reduce their visual impact.

The proposed alternatives have the potential to affect the visual resource. VQO compliance was based 

on map review and on-the-ground knowledge of topography and vegetation of the area. Representative 

route addition samples were also field checked to verify VQO compliance. VQO compliance of proposed 

unauthorized route additions is documented in the project record. The “Assumptions specific to visual 

resources analysis” section lists assumptions used to determine VQO compliance. To determine the visual 

effects of the alternatives overall, geographic information system (GIS) was used to analyze the 

alternatives in regards to key viewshed locations and VQOs assigned to the area. Effects to key viewsheds 

and compliance with retention and partial retention VQOs are measurement indicators for this analysis. 

VQOs provide direction for visual resources to determine the level of acceptable change for the 

landscape and are established in the TNF LRMP. This analysis uses VQOs to determine if the alternatives 

meet Forest Plan standards and guidelines by comparing the degree of alterations from an otherwise 

natural-appearing forest landscape. The TNF LRMP and Agriculture Handbook Number 462 provide 

definitions for the VQOs used for the visual management of lands administered by the TNF NF:

Preservation VQO – This VQO provides for ecological changes only. Management activities, except 

for very low visual impact recreation facilities, are prohibited.

Retention VQO – Activities are not evident to the casual forest visitor. This VQO provides for 

management activities that are not visually evident. Under retention, activities may only repeat form, line, 

color, and texture which are frequently found in the characteristic landscape. 

Partial Retention VQO – Activities may be evident but must remain subordinate to the characteristic 

landscape. Activities may also introduce form, line, color, or texture which are found infrequently or not 

at all in the characteristic landscape, but they should remain subordinate to the visual strength of the 

characteristic landscape. 

Modification VQO – Activities may dominate, but must utilize naturally-established form and 

texture. These areas should appear natural when viewed in foreground or middleground situations.

Maximum Modification VQO – Activities may dominate, but should appear as a natural occurrence 

when viewed in background situations.

Assumptions specific to visual resources analysis:

• Based upon the review of Tahoe LRMP, the basic measurement indicator for the visual resources 

is compliance with the retention and partial retention VQOs. 

• As stated in the LRMP EIS, the TNF exhibits diverse and distinctive landscape qualities suited to 

scenic appreciation. An indication of these scenic qualities is the inclusion by California of all four 
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708 – Tahoe National Forest

major roads that traverse the Forest – State Highways 20, 49, 89 and Interstate 80 – in the Master 

Plan of State Highways Eligible for Official Scenic Highway Designation. Currently, California 

has designated portions of Highway 20 and 49 as State Scenic Highways. These routes will be 

used as Key Viewsheds for this analysis.

• The preservation VQO occurs only in the designated (Granite Chief) Wilderness Area and along 

the North Fork of the American Wild and Scenic River; motorized access is not authorized in 

either area. 

• NFTS additions are generally low impact roads or trails, which easily meet the modification 

and/or maximum modification VQO. These VQOs allow for activities, such as roads and trails, 

which dominate the characteristic landscape but utilize naturally-established form and texture.

• The visual resource would benefit from the elimination of dead-end routes. 

• The prohibition of cross country travel would have a beneficial effect on scenery. Travel routes 

would naturally rehabilitate over time as uncharacteristic linear features and lighter colored soils 

would become less visible.

• Changing the road use, season of use, or vehicle class on existing NFTS roads would have no 

effect on scenery. The uncharacteristic linear feature or contrast is the potential visual impact, not 

the type or season of use.

Data Sources

• Tahoe National Forest LRMP for distribution of VQOs and identification of scenic viewsheds 

• Forest’s National Visitor Use Monitoring (NVUM) report to determine the popularity of viewing 

scenery or driving for pleasure.

• Recreation Facility Analysis for deriving recreation program niche

• Forest Service Handbook 462 – The Visual Management System

Visual Resources Indicators

Measurement Indicator 1: The extent to which the proposed NFTS additions fall within the retention 

and partial retention VQOs (number of miles traversing landscapes that are to remain natural to nearnatural appearing in character).

Measurement Indicator 2: Number of key viewsheds that are or have the potential to be affected by 

motorized vehicle travel. Retention and partial retention VQOs are generally assigned to key viewsheds. 

For each alternative determine if proposed NFTS additions are in compliance with VQOs assigned to the 

key viewsheds. 

Visual Resources Methodology by Management Action

1. Direct/indirect effects of the prohibition of cross country motorized vehicle 

travel. 

2. Direct/indirect effects of adding facilities (presently unauthorized roads, trails, 

and “Open Areas”) to the NFTS. 

Short-term timeframe: 1 year
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Long-term timeframe: 20 years, the approximate length of time for natural rehabilitation of 

unauthorized routes. 

Spatial boundary: The “viewshed” is the unit of spatial analysis when considering effects associated 

with changes in the NFTS or season of use. Viewsheds encompass lands generally seen from a travel 

route or use point such as a campground. The following travel routes and their associated viewsheds 

have been identified as key viewsheds for this analysis: State Highways 20, 49, 89 and Interstate 80. 

Indicator(s): The extent to which the proposed NFTS addition falls within the retention and partial 

retention VQOs (number of miles traversing landscapes that are to remain natural to near-natural 

appearing in character). 

Methodology: VQO compliance was based on map review and on-the-ground knowledge of 

topography and vegetation of the area. Representative samples were also field checked to verify VQO 

compliance. GIS analysis of added routes in relation to retention and partial retention VQOs was also 

completed.

Rationale: Compliance with the retention and partial retention visual quality objectives (VQOs).

3. Direct/indirect effects of changes to the existing NFTS [including vehicle class, 

season of use, or reopening Maintenance Level 1 (ML 1) roads, and amendments 

to the Forest Plan].

Short-term timeframe: 1 year

Long-term timeframe: 20 years, the approximate length of time for natural rehabilitation of 

unauthorized routes. 

Spatial boundary: The “viewshed” is the unit of spatial analysis when considering effects associated 

with changes in the NFTS or season of use. Viewsheds encompass lands generally seen from a travel 

route or use point such as a campground. The following travel routes and their associated viewsheds 

have been identified as key viewsheds for this analysis: State Highways 20, 49, 89 and Interstate 80. 

Indicator(s): The extent to which the proposed NFTS falls within the retention and partial retention 

VQOs (number of miles traversing landscapes that are to remain natural to near-natural appearing in 

character). Changing the road use, season of use, or vehicle class on existing NFTS roads would have 

no effect on scenery.

Methodology: VQO compliance was based on map review and on-the-ground knowledge of 

topography and vegetation of the area. Representative samples were also field checked to verify VQO 

compliance. GIS analysis of added routes in relation to retention and partial retention VQOs was also 

completed.

Rationale: Compliance with the retention and partial retention visual quality objectives (VQOs).

4. Cumulative Effects.

Short-term timeframe: Not applicable; cumulative effects analysis will be done only for the longterm time frame.

Long-term timeframe: 20 years, the approximate length of time for natural rehabilitation of 

unauthorized routes.
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Chapter 3: Affected Environment and Environmental Consequences – 3.07. Recreation and Visual Resources

710 – Tahoe National Forest

Spatial boundary: The “viewshed” is the unit of spatial analysis for determining cumulative effects. 

Viewsheds encompass lands generally seen from a travel route or use point such as a campground. 

Indicator(s): Number of key viewsheds that are or have the potential to be affected by motor vehicle 

travel. 

Methodology: Identify key forest viewsheds (scenic byway corridors, etc). The following travel 

routes and their associated viewsheds have been identified as key viewsheds for this analysis: State 

Highways 20, 49, 89 and Interstate 80. Identify whether any of these key viewsheds are or have the 

potential to be affected by motor vehicle travel. 

Rationale: Compliance with the retention and partial retention visual quality objectives (VQOs). 

Retention and partial retention VQOs are generally assigned to key forest viewsheds.

Visual Resources: Affected Environment

Americans highly value scenery, or visual quality, within the National Forests. Natural appearing forests 

offer scenes, which are valued as recreational settings and living environments. Such settings contribute 

to the well-being of many individuals in today’s complex and fast-paced society. Conservation of the 

naturally established scenic character of these settings is the primary goal of visual management on all 

National Forests. 

The Tahoe National Forest’s 836,000 acre expanses of winding river canyons include the 38.3-mile 

North Fork American Wild and Scenic River, and the Granite Chief Wilderness area. The Forest scenery 

is known for its diversity, ruggedness, and semi-primitive character. An abundance of scenic river 

canyons and mountain crests offer high-quality settings for a growing number of recreation pursuits. Such 

pursuits include camping, picnicking, sightseeing from motor vehicles, river running and hiking. 

Much of the Forest is visible from areas where users have a high concern for scenic values. Most of 

these areas have been assigned retention and partial retention VQOs but may have other VQOs also 

assigned. The Forest has a high portion of lands with steep to moderately steep slopes and soil colors that 

can sharply contrast with its green forests and other more subtle vegetative patterns. Thus, its overall 

capability to retain a natural appearance when altered is relatively low. Although roads and trails cause 

visual contrasts noticeable on the landscape, as described above, they often provide the platform for 

viewing scenery and other natural features. The top participating activity by Forest visitors based on 2005

National Visitor Use Monitoring Data (NVUM) was: viewing natural features with approximately 54 

percent participating. Viewing natural features was the main activity for approximately 6 percent of 

visitors. Other popular activities included: relaxing, hiking-walking, viewing wildlife, and driving for 

pleasure. Driving for pleasure was the sixth most popular activity with about 16 percent of Forest visitors 

reporting participation in this activity. Extensive motorized vehicle use occurs forestwide on the existing 

road system.

Visual impacts from motorized off-highway vehicle use include unimproved roads and trails, which 

often create linear alterations on the landscape that have the potential to be viewed by Forest visitors 

looking from other locations or by Forest visitors traveling on the route itself. Roads and trails, when 

viewed from another location, have the potential to create negative visual impacts by introducing non-
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Tahoe National Forest – 711

characteristic linear features on a non-linear landscape with color contrasts from exposed soils on the 

routes and high use areas. Due to topographic and vegetative screening, seen during field review, these 

deviations are not noticeable in key viewsheds from the travel routes identified in this analysis. In most 

cases, the visual impact is a short duration view of a low impact unimproved road or trail intersecting the 

road or highway. These low impact intersections are generally not evident to the casual Forest visitor, or, 

if they are evident, they remain subordinate to the characteristic landscape. The deviations from the 

characteristic landscape caused by motorized off-highway vehicle use are most noticeable to the person 

riding on the road or trail. No unauthorized inventoried routes are identified in key viewsheds and the 

routes will meet the allocated VQO when viewed from the unauthorized route itself. 

Key Viewsheds

Four highways traversing the Forest were identified by the State of California as eligible State Scenic 

Highways; namely Highways 20, 49, 89, and Interstate 80. As designated in the LRMP, the foreground 

distance zones of these routes are generally managed with a retention VQO in the foreground and partial 

retention for middle-ground viewing distances.

Visual Quality Objectives (VQOs)

Table 3.07-16 shows the acreage distribution of the retention and partial retention VQOs on the TNF. 

These objectives are used to define the amount of acceptable landscape alteration for a particular project.

Table 3.07-16. Forest acres and mileage of inventoried unauthorized routes and closed NFTS roads still

receiving motorized use by retention and partial retention visual quality objectives (National Forest System 

lands only)

Visual Quality Objective Acres Percent of total Forest 

acres 

Mileage of inventoried unauthorized

and closed NFTS motorized routes

still receiving motorized use 

Retention 142,587 17 236.5

Partial Retention 316,438 38 545.3

Totals +/-836,000 100 1698.3

Acreages may vary from Forest Plan totals due to National Forest land ownership changes 

Visual Resources: Environmental Consequences

See the effects methodology section above regarding how this analysis was conducted. Vehicle class, 

season of use, and the amendment to the TNF LRMP will not be addressed in the discussion of 

environmental consequences by alternative since they do not affect the visual quality of the Forest. The 

alternatives will discuss the affects on visual resources based on the methodology listed previously. Table 

3.07-17 compares the mileage of proposed unauthorized road and trail route additions in retention and 

partial retention VQOs by alternative. Also shown is the mileage of ML 1 roads proposed to be reopened 

in retention and partial retention VQOs by alternative. Mileage of roads with proposed mixed use is not 

included in this table. All other proposed unauthorized route additions are located in modification VQO.
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Table 3.07-17. Miles of route added to the NFTS in retention and partial retention VQO

Action type Indicator - Visual Resources Miles of Unauthorized Routes Added to the NFTS/

Re-opened ML1 Roads

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Additions to 

the NFTS

Retention VQO N/Aa 9.9 0.0 5.3 11.0 9.4 6.7

Partial Retention VQO N/Aa 35.7 0.0 14.2 43.0 37.8 21.5

Reopening ML 

1 Roads to 

motorized use

Retention VQO N/Aa 0.0 0.0 0.1 2.5 0.1 0.1

Partial Retention VQO N/Aa 0.0 0.0 0.0 16.0 0.8 0.0

Subtotal Mileage of routes added to the NFTS 

in Retention or Partial Retention VQO

N/Aa 45.6 0 19.6 72.5 48.0 28.3

a Under Alternative 1 no changes or additions to the NFTS would be made, but unauthorized routes would continue to be used and 

cross country motorized vehicle travel would continue.

Totals may include slight errors due to rounding.

Direct and indirect effects 

Alternative 1 – No Action

Under the No Action Alternative, the existing condition as described in the affected environment section 

would continue. It provides a baseline for comparing other alternatives while no changes would be made 

to the NFTS. Motor vehicle travel by the public would not be limited to designated routes.

Prohibition of cross country wheeled motorized vehicle travel. Under Alternative 1, cross country

motorized vehicle travel would not be prohibited. Approximately 1,698.3 miles of unauthorized routes 

and closed NFTS roads still receiving some motorized use (236.5 miles within Retention VQO and 545.3 

miles within Partial Retention VQO) would continue to be used and would not naturally rehabilitate over 

time. Attempting to quantify effects associated with potential future cross country travel is speculative 

because it is impossible to predict exactly where, when, or how cross country motorized use would occur. 

Cross country travel has the potential to impact retention and partial retention VQO areas, which are 

managed as natural to near-natural appearing in character. In the short-term, due to topographic and 

vegetative screening, the uncharacteristic linear and color effects typically associated with cross country

motorized travel would not be noticeable in the key viewsheds identified for this analysis. However visual 

impacts from cross country motorized use may be noticeable in areas outside of these viewsheds which 

are assigned retention or partial retention VQO. In the long term, the potential of new motorized cross 

country routes developing in key viewsheds would increase. Cross country motorized travel in areas with 

sparse vegetation would be more visible to Forest visitors and the uncharacteristic linear features and 

lighter colored exposed soils would have a negative effect on the visual resource. In most cases, 

uncharacteristic linear features seen on the landscape would not meet retention or partial retention VQO. 

In the long-term, the public would notice more impacts to visual resources from cross country motorized 

travel and anticipated development of additional unauthorized routes. User-created routes would continue 

to be used by all motorized vehicles. Cross country motor vehicle travel would continue, therefore 
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Alternative 1 has the greatest visual impact to the natural-appearing landscape when compared to the 

other alternatives.

Adding facilities (presently unauthorized roads, trails, and “Open Areas”) to the NFTS and 

changes to the NFTS. No additions or changes to the existing NFTS would be made under Alternative 1 

so there would be no direct or indirect effects to scenery from these actions. 

Alternative 2 – Increased Motorized Recreation and Access Opportunities

Alternative 2 adds 59.6 miles of unauthorized routes to the NFTS, establishes four new “Open Areas”

totaling 2,649 acres, and prohibits cross country motorized travel. In this alternative, no Maintenance 

Level 1 (ML 1) roads would be reopened to motorized use.

Prohibition of cross country wheeled motorized vehicle travel. The prohibition of cross country

motorized vehicles would not be noticeable in the short-term as the natural rehabilitation of unauthorized 

routes would take longer than one year. The visual impact from unauthorized routes may be noticeable 

until these areas naturally rehabilitate. Most unauthorized routes and their associated visual impacts are

not noticeable in key viewsheds due to topographic and vegetative screening. If unauthorized motorized 

routes intersect the road or highway, a short duration view of a low impact, unimproved road or trail may 

be noticeable until the route naturally rehabilitates. In the long term, unauthorized motorized vehicle 

routes and impact areas would naturally rehabilitate. 

The effects of this action on visual resources would result in a more natural-appearing landscape.

Compared to the No Action Alternative (Alternative 1), the landscape would, overall, have higher scenic 

integrity than currently exists with less evidence of human activity over time.

Adding facilities (presently unauthorized roads, trails, and “Open Areas”) to the NFTS.

Alternative 2 proposes about 9.9 miles of unauthorized route additions in retention VQO and about 35.7 

miles in the partial retention VQO. Where proposed route additions intersect the road or highway in key 

viewsheds, views of a low impact, unimproved road or trail may occur for short durations, but these 

intersections generally would not be noticeable to the casual Forest visitor. The visual effects from these 

proposed route additions meet the retention and partial retention VQOs. The key viewsheds identified for 

this analysis would not be affected by the proposed unauthorized route additions under this alternative.

Alternative 2 establishes 2,649 acres of new motorized “Open Areas” areas in the Greenhorn area (60 

acres) and Prosser, Boca, Stampede Reservoir areas (2,589 acres). The Greenhorn area is located in partial 

retention VQO area when seen in the middleground of Highway 20 and Interstate 80. Prosser, Boca and 

Stampede areas would be seen in the foreground of the reservoirs and fall within potential middleground 

views from Highway 89 and Interstate 80. The “Open Areas” at Boca, Prosser and Stampede Reservoirs 

would allow motorized travel below the high water mark resulting in temporary uncharacteristic linear 

effects which may be noticeable from within the reservoirs and nearby access roads; however, the OHV 

areas would not be visible in the identified key viewsheds because of topographic and vegetative 

screening. Since the trails and OHV use in these areas would not be noticeable in the key viewsheds 

identified for this analysis, the VQOs assigned to these proposed areas would be met.
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Changes to the NFTS. This action would cause no change in effects for visual resources as it is 

assumed that existing NFTS roads, with road template, are already in place. Changing the road use, 

season of use, or vehicle class allowed to access the route would have no effect on scenery. In Alternative 

2, no ML 1 roads (or road segments) would be reopened to motorized use.

Alternative 3 – Cross country Motorized Travel Prohibition Only – No Changes to the Current NFTS

Alternative 3 prohibits cross country motorized travel and proposes no additions to the existing system of 

roads and trails. 

Prohibition of cross country wheeled motorized vehicle travel. The prohibition of cross country

motorized vehicles would not be noticeable in the short-term as the natural rehabilitation of unauthorized 

routes would take longer than one year. The visual impact from unauthorized routes may be noticeable 

until these areas naturally rehabilitate. Most unauthorized routes and their associated visual impacts are

not noticeable in key viewsheds due to topographic and vegetative screening. If unauthorized motorized 

routes intersect the road or highway, a short duration view of a low impact, unimproved road or trail may 

be noticeable until the route naturally rehabilitates. In the long term, unauthorized motorized vehicle 

routes and impacted areas would naturally rehabilitate. Alternative 3, when compared to the other 

alternatives, would have the least impact to visual resources as most unauthorized motorized routes would 

naturally rehabilitate over time, resulting in a more natural-appearing landscape.

Adding facilities (presently unauthorized roads, trails, and “Open Areas”) to the NFTS and 

changes to the NFTS. Alternative 3 proposes no additions or changes to the existing NFTS. In the long 

term the landscape viewed from existing system roads and trails would be more natural-appearing.

Alternative 4 – Increased Resource Protection

Alternative 4 adds about 26.3 miles of unauthorized routes as roads or trails and reopens one ML 1 road 

(0.1 miles). No motorized “Open Areas” would be established. 

Prohibition of cross country wheeled motorized vehicle travel. The effects on visual resources 

from the prohibition of cross country motorized vehicles under Alternative 4 would be the same as those 

described for Alternative 2. See the direct and indirect effects of the prohibition of cross country 

motorized vehicle travel section under Alternative 2. The effects of this action on visual resources would 

result in a more natural-appearing landscape. Compared to the No Action Alternative (Alternative 1), the 

landscape would, overall, have higher scenic integrity than currently exists with less evidence of human 

activity over time.

Adding facilities (presently unauthorized roads, trails, and “Open Areas”) to the NFTS.

Alternative 4 proposes 5.3 miles of unauthorized route additions in the retention VQO and 14.2 miles in 

the partial retention VQO. The visual effects from these proposed unauthorized route additions would 

achieve the retention and partial retention VQOs. Where proposed route additions would intersect a road 

or highway, views of a low impact, unimproved road or trail may occur for short durations, but these 

intersections generally would not be noticeable to the casual Forest visitor. The key viewsheds identified 

for this analysis would not be affected by the proposed unauthorized route additions under this alternative.
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The addition of unauthorized roads and trails under this alternative would have similar effects as those 

described under Alternative 2, but to a more beneficial degree due to fewer miles of additions to the 

NFTS and no “Open Areas” would be established in retention and partial retention VQO.

Changes to the NFTS. The effects on visual resources from this action would be the same as those 

described for Alternative 2 except that 0.1 mile of ML 1 road would be reopened within the retention 

VQO. Where this ML 1 Road would intersect a road or highway, views of a low impact, unimproved road 

or trail may occur for short durations, but would not be noticeable to the casual Forest visitor. The key 

viewsheds identified for this analysis would not be affected by this proposed change to the existing 

NFTS. The changes to the existing NFTS under Alternative 4 would have similar effects as those 

described under Alternative 2, only slightly greater.

Alternative 5 – Increased Motorized Recreation Plus Reopening Maintenance Level 1 and Temporary 

Roads

Alternative 5 prohibits cross country motorized travel, adds 80.4 miles of unauthorized routes as roads or 

trails, and reopens portions of 113 ML 1 roads (93.4 total miles). No new motorized “Open Areas” would 

be established.

Prohibition of cross country wheeled motorized vehicle travel. The effects on visual resources 

from the prohibition of cross country motorized vehicles under Alternative 5 would be the same as those 

described for Alternative 2. See the direct and indirect effects of the prohibition of cross country

motorized vehicle travel section under Alternative 2. The effects of this action on visual resources would 

result in a more natural-appearing landscape.

Adding facilities (presently unauthorized roads, trails, and “Open Areas”) to the NFTS.

Alternative 5 proposes about 11 miles of unauthorized route additions in the retention VQO and about 43 

miles in the partial retention VQO. The addition of unauthorized roads and trails under Alternative 5 

would have similar impacts to the visual resource as those described under Alternative 2 but the negative 

impact to the visual resource would be slightly greater. See the direct and indirect effects of adding 

facilities to the NFTS section under Alternative 2. The visual effects from these proposed route additions 

would achieve the retention and partial retention VQOs. The key viewsheds identified for this analysis 

would not be affected by the proposed unauthorized route additions under this alternative.

Changes to the NFTS. The effects on visual resources from implementing Alternative 5 would be 

similar to those described for Alternative 2; however, Alternative 5 proposes to reopen 2.5 miles of ML 1 

roads within the retention VQO and 16 miles of ML 1 roads within the partial retention VQO. The visual 

effects from these proposed changes to the NFTS would achieve the retention and partial retention VQOs. 

The key viewsheds identified for this analysis would not be affected by the proposed unauthorized route 

additions under this alternative. The addition of reopening ML 1 roads and trails under this alternative 

would have similar effects as those described under Alternative 2, but the negative impact to the visual 

resource would be greater. 
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716 – Tahoe National Forest

Alternative 6 – Preferred Alternative – Motorized Access and Resource Protection

Alternative 6 prohibits cross country motorized travel, adds 61.4 miles of unauthorized routes to the 

NFTS, establishes 244 acres of new motorized “Open Areas” in the Boca, Prosser, and Stampede area, 

and reopens thirteen ML 1 roads totaling 11.4 miles.

Prohibition of cross country wheeled motorized vehicle travel. The effects on visual resources 

from the prohibition of cross country motorized vehicles under Alternative 6 would be the same as those 

described for Alternative 2. See the direct and indirect effects of the prohibition of cross country

motorized vehicle travel section under Alternative 2. The effects of this action on visual resources would 

result in a more natural-appearing landscape.

Adding facilities (presently unauthorized roads, trails, and “Open Areas”) to the NFTS. The 

addition of unauthorized roads, trails, and areas under Alternative 6 would have similar effects as those 

described under Alternative 2 but to a slightly greater degree. See the direct and indirect effects of adding 

facilities to the NFTS section under Alternative 2.

Alternative 6 proposes about 9.3 miles of unauthorized route additions in the retention VQO and 

about 37.8 miles in the partial retention VQO. The visual effects from these proposed route additions 

would achieve the retention and partial retention VQOs. The key viewsheds identified for this analysis 

would not be affected by the proposed unauthorized route additions under this alternative.

Alternative 6 also establishes about 244 acres of new off-highway vehicle (OHV) motorized “Open 

Areas” areas in the Prosser, Boca, Stampede Reservoir areas. Prosser, Boca and Stampede areas would be 

seen from the foreground of the reservoirs and fall in potential middleground views from Highway 89 and 

Interstate 80. These proposed “shoreline” “Open Areas” would allow motorized travel below the high 

water mark in the reservoir resulting in minor-temporary uncharacteristic linear and color effects which 

may be noticeable from within the reservoirs and nearby access roads; however, the OHV “Open Areas”

would not be visible in the identified key viewsheds because of topographic and vegetative screening. 

Since the motorized use in these areas would not be noticeable in the key viewsheds identified for this 

analysis, the VQOs assigned to these proposed areas would be met. 

Changes to the NFTS. The effects on visual resources from this action would be the similar as those 

described for Alternative 2. However, 0.1 miles of ML 1 roads are proposed to be reopened within the 

retention VQO and 0.8 miles within the partial retention VQO. The visual effects from these proposed 

changes to the NFTS would achieve the retention and partial retention VQOs. The key viewsheds 

identified for this analysis would not be affected by the proposed unauthorized route additions under this 

alternative. The addition of reopening ML 1 routes under this alternative would have similar effects as 

those described under Alternative 2 but the impacts to the visual resource would be slightly greater. 

Alternative 7 – Proposed Action as Identified in the Notice of Intent (NOI)

Alternative 7 prohibits cross country motorized travel, adds 36.7 miles of unauthorized routes as 

motorized trails, and reopens 1.1 miles of ML 1 road on two roads. No new motorized “Open Areas” 

would be established.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment and Environmental Consequences – 3.07. Recreation and Visual Resources

Tahoe National Forest – 717

Prohibition of cross country wheeled motorized vehicle travel. The effects on visual resources 

from the prohibition of cross country motorized vehicles under Alternative 7 would be the same as those 

described for Alternative 2. See the direct and indirect effects of the prohibition of cross country 

motorized vehicle travel section under Alternative 2. The effects of this action on visual resources would 

result in a more natural-appearing landscape than Alternative 1.

Adding facilities (presently unauthorized roads, trails, and “Open Areas”) to the NFTS.

Alternative 7 proposes approximately 6.7 miles of unauthorized route additions (motorized trails) in the 

retention VQO and about 21.5 miles in the partial retention VQO. The visual effects from these proposed 

additions would achieve the retention and partial retention VQOs. Where proposed route additions 

intersect a road or highway, views of a low impact, unimproved road or trail may occur for short 

durations, but these intersections generally would not be noticeable to the casual Forest visitor. The key 

viewsheds identified for this analysis would not be affected by the proposed additions under this 

alternative. The addition of unauthorized roads and trails and under this alternative would have similar 

effects as those described under Alternative 2. 

Changes to the NFTS. The effects on visual resources from this action would be similar to those 

described for Alternative 4 since both alternatives reopen 0.1 miles of ML 1 road within the retention 

VQO. The visual effects from these proposed changes to the NFTS would achieve the retention and 

partial retention VQOs. 

Cumulative Effects

Alternative 1 – No Action

The cumulative effects analysis for scenery considers the impact of the alternatives when combined with 

past, present, and reasonably foreseeable future actions and events. The following travel routes and their 

associated viewsheds have been identified as key viewsheds for this analysis: State Highways 20, 49, 89

and Interstate 80. Retention and partial retention VQOs are assigned to these key viewsheds. In analyzing 

cumulative effects of Motorized Travel Management, the TNF considered effects from all present and 

reasonably foreseeable future actions that have potential for changing road density within the analysis 

area. These actions affecting the visual resource include: new road construction, reconstruction, 

decommissioning and/or adding roads to the Forest transportation system. Impacts from human activities 

are primarily the result of past logging, road building, and, to a lesser extent, mining activity. Most of the 

Forest has a natural appearance, while the remainder appears altered. Most of the strong visual contrasts 

occur either in the background distance zone or out of sight of major highways, trails, or recreation areas.

Since cross country motorized travel would continue under Alternative 1, the unpredictable 

proliferation of user-created routes would continue. The present and reasonably foreseeable future

activities would continue to form the landscape aesthetics and recreation opportunities. Recreation 

activities and developments and travel management activities, including the NFTS, most often form the 

viewing platform and opportunities for viewing scenery. Any new road construction, reconstruction, 

decommissioning and/or adding roads to the Forest transportation system are expected to meet the VQOs 

assigned to the management area in which they occur. Abandoning, closing or decommissioning roads 
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Chapter 3: Affected Environment and Environmental Consequences – 3.07. Recreation and Visual Resources

718 – Tahoe National Forest

generally results in a more naturally appearing landscape. Most of the strong visual contrasts would 

continue to occur either in the background distance zone, in areas not assigned retention or partial 

retention VQO, or out of sight of major highways, trails, or recreation areas. Although the majority of the 

Forest would continue to have a natural appearance, it is anticipated that the No Action Alternative along 

with the past, present, and reasonably foreseeable future actions would result in an increase in Forest 

lands which appear altered.

Action Alternatives

See the cumulative effects section under Alternative 1 for the past, present, and reasonably foreseeable 

future actions considered and other information on how the cumulative effects analysis was conducted. 

Alternatives 2, 4, 5, 6, and 7. The present and reasonably foreseeable future activities would 

continue to form the landscape aesthetics and recreation opportunities. Recreation activities and 

developments and travel management activities, including the NFTS, most often form the viewing 

platform and opportunities for viewing scenery. Any new road construction, reconstruction, 

decommissioning and/or adding routes to the Forest transportation system are expected to meet the VQOs 

assigned to the management area in which they occur. Abandoning, closing or decommissioning roads 

generally results in a more naturally appearing landscape.

The majority of the Forest would continue to have a natural appearance. Areas visually impacted by 

unauthorized motorized routes would continue to rehabilitate over time resulting in a more naturalappearing landscape. It is anticipated that implementation of this alternative along with the past, present, 

and reasonably foreseeable future actions would result in no cumulative effects to visual resources. With 

cross country motorized travel prohibited, the unpredictable proliferation and concentration of 

unauthorized routes would end. The landscapes viewed in the key viewsheds identified for this analysis 

would have more natural-appearing characteristics. Overall, the landscape would have higher scenic 

integrity than currently exists with less evidence of human activity over time. The cumulative effects of 

Alternatives 2, 4, 5, 6, and 7 would be the same.

Alternative 3. The cumulative effects of Alternative 3 would be slightly less impacting to visual 

quality compared to the cumulative effects described for Alternatives 2, 4, 5, 6, and 7 due to the lack of 

additions to the NFTS.

Compliance with the Forest Plan and Other Direction

Alternative 1 allows cross country motorized travel, putting visual resources at risk and promotes changes 

to the landscape in key viewsheds that may not comply with Forest Plan prescribed retention and partial 

retention VQOs in the long term. All action alternatives would meet the visual resource standards and 

guidelines outlined in the Forest Plan. All action alternatives have been designed to meet the retention and 

partial retention VQOs as viewed from the travel routes identified as key viewsheds for this analysis.
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Chapter 3: Affected Environment and Environmental Consequences – 3.07. Recreation and Visual Resources

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Summary of Effects Analysis across All Alternatives for 

Recreation and Visual Resources

This section summarizes the effects analysis by discussing how well each alternative addresses the 

recreation and visual resources for each measurement indicator. The following ranks were used in Tables 

3.07-18, 19, and 20: A score of 7 indicates the alternative has the least impact for recreation or visual 

resource measurement indicators. A score of 1 indicates the alternative has the most impact for recreation 

and visual resource measurement indicator.

Table 3.07-18. Non-motorized Recreation Summary

Indicator Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Non-motorized recreation opportunity 1 3 7 6 2 5 4

Impact of proposed changes on the NFTS on 

neighboring private and federal lands

1 4 7 6 2 3 5

Non-motorized overall ranking 1 3 7 6 2 4 5

Table 3.07-19. Motorized Recreation Summary

Indicator Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Motorized recreation opportunity 7 5 1 2 6 4 3

Motorized access to dispersed recreation 7 4 1 3 5 6 2

Motorized overall ranking 7 4 1 2 6 5 3

Table 3.07-20 Visual Resources Summary

Indicator Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Relative benefit to visual resources 1 4 7 6 2 3 5

In Table 3.07-18, non-motorized recreation measurement indicators summarized include: nonmotorized recreation opportunity and impact of proposed changes to the NFTS on neighboring private 

and federal lands (dust, noise, use conflicts). Alternative 1 would have the most impact on non-motorized 

recreation opportunity and the most impact on neighboring private and federal lands and wilderness areas

(dust, noise, use conflicts) in that continued cross country motorized travel would have the most impacts 

on these measurement indicators in the long term. Alternatives 3 and 4 would have the least impact 

regarding these measurement indicators by providing the most non-motorized recreation opportunity and 

reducing the impact of proposed changes to the NFTS on neighboring private and federal lands (dust, 

noise, use conflicts). Alternatives 6 and 7 are about equal in providing the next least reduction in the 

beneficial effects to non-motorized recreation and impacts on neighboring private and federal lands. 

Alternatives 2 and 5 would also provide beneficial effects to non-motorized recreation and reduce impacts 

on neighboring private and federal lands and wilderness areas by prohibiting cross country motorized 

travel, but less beneficial effects regarding these measurement indicators when compared to the other 

alternatives
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Chapter 3: Affected Environment and Environmental Consequences – 3.07. Recreation and Visual Resources

720 – Tahoe National Forest

In Table 3.07-19, motorized recreation measurement indicators summarized include: motorized 

recreation opportunity and amount of motorized access to dispersed recreation. Alternative 1, which 

would continue to allow cross country motorized travel, would have the least impact regarding these 

measurement indicators by providing the most motorized recreation opportunity and the most motorized 

access to dispersed recreation of any alternative. With no route additions or mixed use roads proposed in 

Alternative 3, this alternative would have the most impacts on these measurement indicators. Alternatives 

4 and 7 are tied for second most impact to the motorized indicators, these alternatives would provide 

moderate additions and access to dispersed recreation. Alternative 2 would impact the motorized 

indicators less than Alternatives 4 and 7 with additional additions to the NFTS, establishing the greatest 

amount of “Open Areas,” and increased motorized access to dispersed recreation. Finally Alternatives 5 

and 6 are relatively equal in regard to motorized recreation and motorized access to dispersed recreation, 

behind Alternative 1. However Alternative 6 includes the second greatest establishment of “Open Area” 

acreage, providing this alternative a slight edge when compared to Alternative 5.

Alternative 1 is the worst for addressing compliance with the retention and partial retention VQOs 

and key viewsheds affected by the proposed NFTS in that continued cross country motorized travel would 

likely impact retention and partial retention VQOs and the key viewsheds identified for this analysis in 

the long term. All action alternatives would be beneficial to visual resources in varying degrees by 

prohibiting cross country motorized travel. All action alternatives would meet retention and partial 

retention VQOs. Key viewsheds identified for this analysis would not be affected by the proposed NFTS 

in any action alternative.
Chapter 3.08 

Transportation 

Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Tahoe National Forest – 721

3.08. Transportation _____________________________________

Affected Environment

Introduction

This section of the environmental analysis examines the extent to which alternatives respond to 

transportation facilities direction established in the Tahoe National Forest Land and Resource 

Management Plan (LRMP). The LRMP transportation facilities direction was established under the 

implementing regulations of the National Forest Management Act (NFMA) and the National Forest Roads 

and Trails Act (FRTA). The National Forest Transportation System (NFTS) consists of roads and trails. 

The NFTS provides for protection, development, management, and utilization of resources on the 

National Forests.

There are other roads and trails existing on the Forest that are not currently part of the NFTS. 

Transportation facilities considered in this analysis include roads and trails that are suitable for motor 

vehicle use. This analysis considers changes needed to the NFTS to meet the purpose and need of this 

analysis. Decisions regarding changes to the transportation facilities must consider: 1) providing for 

adequate public safety, and 2) providing adequate maintenance of the roads and trails that would be 

designated for public use. The analysis in this section primarily focuses on these two aspects of the NFTS.

Analysis Framework: Statute, Regulation, Forest Plan,

and Other Direction

Direction relevant and specific to the proposed action as it affects transportation facilities includes:

Transportation Rule (36 CFR 212, 251, 261 and 295): The alternatives in this EIS are designed 

specifically to implement the requirements of the November 9, 2005, rule for travel management; 

Designated Routes and Areas for Motor Vehicle Use. Title 36, Code of Federal Regulations, Part 212 (36 

CFR 212) is the implementing regulation for the National Forest Roads and Trails Act (FRTA), and it 

includes portions of the Travel Management Rule published in the Federal Register on November 9, 2005. 

Part 212 provides criteria for designation of roads and trails. Providing safe transportation facilities and 

considering the affordability of maintaining the transportation facilities are two of the criteria.

The Tahoe National Forest Land and Resource Management Plan (LRMP) goals call for 

providing a broad spectrum of recreational opportunities in accordance with need, demand, and type of 

use (LRMP page 97). Additionally, the Forest Plan calls for closures where obvious conflicts exist (LRMP 

page 97). Furthermore, the Forest Plan calls for providing safe recreational access (LRMP page 100).

Forest Service Manual Sections 2350 and 7700 contain agency policy for management of the 

National Forest Transportation System. The policy requires the development of trail management 

objectives (TMOs) and road management objectives (RMOs). The TMOs and RMOs document the 

purpose of each trail or road. The purpose for the trail or road sets the parameters for maintenance 

standards needed to meet user needs, resource protection, and public safety. Forest Service Handbook 

7709.59, Road System Operation and Maintenance Handbook, describes the maintenance management 
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Chapter 3: Affected Environment & Environmental Consequences – 3.08. Transportation

722 – Tahoe National Forest

system the Forest Service uses and the maintenance standards needed to meet RMOs for the road system 

and includes considerations for public safety.

Regional Forester’s Letters. Direction related to motorized mixed use is contained in Regional 

Forester’s letters, file code 7700/2350, dated 08/26/06, 06/20/07, and 1/13/09. These letters provide 

procedures National Forests in the Pacific Southwest Region will use to evaluate safety aspects of public 

travel on roads when proposed changes to the NFTS will allow both highway-legal and non-highwaylegal traffic on a road (motorized mixed use).

The California Vehicle Code (CVC). The CVC regulates the use of motor vehicles in California, 

including motor vehicles used on the national forests. The CVC sets safety standards for motor vehicles 

and vehicle operators. It defines the safety equipment needed for highway-legal and non-highway-legal 

vehicles. It also defines the roads and trails where non-highway-legal motor vehicles may be operated.

Background

A majority of Tahoe National Forest (TNF) visitors travel on NFTS roads. Roads have opened the TNF to 

millions of national and international visitors. Forest roads are also an integral part of the transportation 

system for rural counties. They provide access for research, fish and wildlife habitat management, 

grazing, timber harvesting, fire protection, mining, insect and disease control, and private land use in 

addition to recreation opportunities.

Roads in the NFTS are not public roads in the same sense as roads that are under the jurisdiction of 

State and county road agencies. NFTS roads are not intended to meet the transportation needs of the 

public at large. Instead, they are authorized only for the use and administration of National Forest System

lands. Although generally open and available for public use, that use is at the discretion of the Secretary 

of Agriculture. Through authorities delegated by the Secretary, the Forest Service may restrict or control 

traffic to meet specific management direction (USDA Forest Service, Forest Service Manual 7731).

The TNF has approximately 2,900 miles of NFTS roads. Roads are defined as motor vehicle 

travelways over 50 inches wide, except those designated and managed as a trail. Trails, including offhighway vehicle (OHV) trails, are covered further in the recreation section (Chapter 3.07) of this EIS.

Some roads and trails are present on the acres where the decision to prohibit cross country travel may

be made. These routes are not currently authorized for motor vehicle use by the public. There are also 

closed NFTS roads in these areas which are still receiving unauthorized motor vehicle use. These routes 

would continue experiencing use in the No Action Alternative, while some would be added to the NFTS 

in the action alternatives as roads or trails designated for motor vehicle use.

NFTS roads are each maintained in one of three categories: Maintenance Level 1 roads closed to 

motor vehicles in long term storage (closed roads), Maintenance Level 2 roads maintained for highclearance vehicles only (high clearance roads), and Maintenance Level 3 to 5 roads maintained for 

standard four-wheel passenger cars (passenger car roads). Those roads maintained for standard passenger 

cars are subject to the Highway Safety Act and are considered by the Forest Service to be highways for 

purposes of the California Vehicle Code (CVC).
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Chapter 3: Affected Environment & Environmental Consequences – 3.08. Transportation

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Costs and Funding for Road Maintenance

Need for Maintenance and Administration

NFTS roads must be maintained to avoid problems that can arise when they fall into disrepair. Each year, 

the TNF prepares a road maintenance plan, which lines out the road work for the year. Resource 

protection and public safety are the maintenance priorities. The Travel Management Rule (36 CFR 

212.55) requires consideration of the need for maintenance and administration of the designated NFTS. 

Costs associated with administration of NFTS facilities include costs for needed maintenance work that 

has not been completed for various reasons (deferred maintenance) and costs of maintenance that should 

be performed routinely to maintain the facility to its current standard (annual maintenance). Routine 

maintenance includes items like the repair of drainage features such as water bars and the repair and/or 

replacement of signage. Administration needs include database management as well as permit issuances.

In recent years, annual road maintenance budgets have not been sufficient to maintain the entire road 

system to standard. This has led to an increase in deferred maintenance. Deferred maintenance is work 

that can be deferred without loss of serviceability. In past decades, commercial users (typically timber 

purchasers) maintained a substantial portion of the NFTS roads on the TNF during timber sale activities.

With the decrease in timber sales, however, fewer roads are being fully maintained (meaning deferred 

maintenance needs increased). An estimated 28 percent of the TNF road system was fully maintained in 

2007. Table 3.08-1 presents average annual maintenance costs for the TNF.

Table 3.08-1. Average Costs for Annual Road and Trail Maintenance in the Tahoe National Forest

Maintenance Class Existing Miles Cost per Mile Annual Cost

Closed Roads, ML 1 567.1 $225 $127,597

High Clearance Roads, ML 2 1,492.8 $1,143 $1,706,270

Passenger Car, ML 3 522.4 $10,870 $5,678,488

Passenger Car, ML 4&5 196.0 $14,107 $2,764,972

Trail Open to All Trail Vehicles 133.9 $1,350 $180,765

Trail Open to ATVs 25.5 $1,275 $32,512

Trail Open to Motorcycles Only 168.8 $1,500 $253,200

Sources: National Road Maintenance Cost Guide adjusted for the Forest averages. Trails: Tahoe.

Availability of Resources

The Federal budget currently exceeds revenues. Revenues are expected to increase, but mandatory 

spending will increase at a faster rate. As a result, federal discretionary spending will decrease, likely 

leading the Forest Service to experience declining budgets through 2017. Figure 3.08-1 shows a graph of 

economic growth and mandatory program spending. The GDP is projected to increase, but 

Medicare/Medicaid and Social Security outlays are projected to increase at faster rates.
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Chapter 3: Affected Environment & Environmental Consequences – 3.08. Transportation

724 – Tahoe National Forest

Figure 3.08-1. Congressional Budget Office’s Projected Growth of the U.S. Economy and Federal Spending 

for Major Mandatory Programs, 2007-2017

Source: Congressional Budget Office. The Budget and Economic Outlook: Fiscal Years 2008-2017. January 2007.

Forest Service funding for road maintenance and administration has generally decreased over the last

five years. Collections from commercial users can only be spent on roads where collections were made. 

Maintenance performed by non-Forest Service funds varies greatly from year to year and tends to be work 

associated with timber haul. For example, the purchaser may blade a road before hauling timber on it.

Refer to Table 3.08-2.

Table 3.08-2. Tahoe National Forest’s Past Years’ Road Budgets (in nominal dollars)

Source:

Fiscal Year

2003 2004 2005 2006 2007

Base Allocation 1,075,644 903,000 751,000 719,000 924,300

Collections from Cooperative Agreements 1,006,629 535,324 187,728 226,260 310,373

Maintenance Performed by Non-Forest Service Funds 642,000 223,204 25,000 129,500 *

*Fiscal Year 2007 data was not required to be submitted.

Public Safety

Public safety affects the selection of geometric elements and design speed of roads, requires the 

examination of possible hazards and corrective actions needed, and identifies the needs for traffic control 

and maintenance activities (USDA Forest Service Handbook 7709.56).

Conflicts among Different Classes of Motor Vehicle Uses - Motorized Mixed Use

NFTS roads are designed primarily for use by highway-legal vehicles (motor vehicles that are licensed or 

certified for general operation on public roads within the State), such as passenger cars or log trucks.

Some NFTS roads also provide recreational access for all-terrain vehicles and other non-highway-legal 
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Tahoe National Forest – 725

motor vehicles. Motorized mixed use (MMU) is defined as designation of an NFS road for use by both 

highway-legal and non-highway-legal motor vehicles (USDA Forest Service, Engineering Publication 

EM-7700-30). Designating NFTS roads for motorized mixed use involves safety and engineering 

considerations.

The California Vehicle Code (CVC) requires motor vehicles operated on highways be highway-legal 

and be operated by licensed drivers. The CVC allows the operation of non-highway-legal vehicles 

operated by unlicensed drivers on roughly graded roads. The Forest Service considers roads maintained 

for high clearance vehicles (Maintenance Level 2) as roughly graded and considers operation of OHVs on 

these roads as consistent with state law.

The policy of Region 5 is to conduct a motorized mixed use analysis on all roads maintained for 

passenger cars where mixed use is proposed and on any high clearance roads that have a crash history or 

where mixed use was not allowed in the past. The baseline for the analysis will be Forest Service 

regulations and directives and applicable State and local laws. The qualified engineer determines how 

detailed the analysis is to be and may choose to do an evaluation based on factors in EM-7700-30 or other 

factors. Qualified Engineer is defined as “An engineer who by experience, certification, education, or 

license is technically trained and experienced to perform the engineering tasks specified and is designated 

by the Director of Engineering, Regional Office” (FSM 7705). The qualified engineer determines the 

factors to be considered for the specific road, road segment, or road system being analyzed. Based on the 

analysis conducted, the qualified engineer will determine the probability of a crash occurring and the 

severity of the crash. He or she may also provide mitigation measures that would tend to reduce the 

probability or severity of a crash. Under certain conditions, the qualified engineer may document 

engineering judgment without preparing a full engineering report. Otherwise, when issues are more 

complex, the qualified engineer will prepare a detailed engineering report.

Speed, Volume, Composition, and Distribution of Traffic

Roads on the TNF are used by a variety of vehicles, including logging trucks, wood chip vans, passenger 

cars, pick-up trucks, recreation vehicles and OHV’s. Traffic volumes change depending on the time of 

year and activities occurring along the road. Forest roads experience the highest vehicle use when 

recreationists, logging trucks, wood chip vans, and agency personnel all need the same road at the same 

time, often in the summer.

Compatibility of Vehicle Class with Road Geometry and Road Surfacing

Roads are designed based on design vehicles (vehicles with representative weight, physical dimensions, 

and operating characteristics). Design vehicles are selected based on the largest vehicle likely to use the 

facility or facilities accessed by the proposed road. For example, if a new road is planned for a fuels 

project on the TNF, the design vehicle would be a wood chip van or logging truck.

Additionally, the volume, composition, distribution, and whether the road is subject to the Highway 

Safety Act are elements of traffic criteria used in the design of turnouts, road widths, surfacing, safety 

features, and traffic control. Roads designed and maintained for high clearance vehicles are not subject to 
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Chapter 3: Affected Environment & Environmental Consequences – 3.08. Transportation

726 – Tahoe National Forest

the Highway Safety Act. The applicability of the Highway Safety Act is determined during transportation 

system planning.

As stated, forest roads were designed primarily for highway-legal vehicles. Since some non-highwaylegal vehicle classes differ from highway-legal vehicles, the qualified engineer considered how those 

different classes can be expected to function depending on the road characteristics.

Effects Analysis Methodology

Transportation Specific Assumptions

• Any motor vehicle use authorized by state law is occurring on the NFTS unless there are Forest 

specific prohibitions.

• Motor vehicle use by special use permit or other permitted activities are outside the scope of this 

decision (for example, fuelwood gathering, motorized SUP events, recreation residences, etc.)

• Eligible motorized trail vehicle classes are high clearance trail vehicles (4WD, etc.), ATVs, and 

motorcycles. Low clearance highway legal vehicles are not prohibited on trails but would not be 

found using trails.

• There is some cost for maintenance that will have to be borne by the Forest Service for any route 

open to motor vehicle use by the public.

• State law regulating motor vehicle drivers sets the standard of care for the safety of drivers 

themselves and other users of the NFTS.

Transportation Sources of Information

Information on individual roads and trails can be found in Appendix A (Site Specific Road, Trail and 

Open Area Information) and Appendix J (Roads Analyzed for Motorized Mixed Use). Additional 

information including the INFRA Database and previous NEPA decisions is part of the project record.

Measurement Indicators

Measurement Indicators are intended to address how each action individually (via direct and indirect 

effects) and each alternative as the sum total of its proposed actions (via cumulative effects) respond to 

the need for a safe and affordable NFTS. Direct effects of this decision are due to additions to the NFTS 

and changes in class of vehicle allowed on NFTS roads and trails. Conflicts with other resources are 

examined in other sections.

The measurement indicators used to display differences between the effects of the alternatives on 

NFTS roads and trails are: 1) Public Safety, and 2) Affordability.

Public Safety

36 CFR 212.55 requires public safety be considered when designating roads, trails, and areas for motor 

vehicle use. The proposed additions and changes to the NFTS have been evaluated for their effects on 

public safety. Refer to Appendix A (Site Specific Road, Trail and Open Area Information) for specific 

information on each road or trail considered to be added to the NFTS.
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Affordability

36 CFR 212.55 requires consideration of the need for maintenance and administration of the designated 

NFTS. NFTS expenses include needed maintenance work that has not been completed (deferred 

maintenance) and costs of routine maintenance to maintain the facility at its current standard (annual 

maintenance). Proposed changes to the NFTS may have additional implementation costs such as sign 

installation and resource improvements.

A current estimate of road deferred maintenance on the TNF is $115,000,000. This value is based on a 

random sample of deferred maintenance needs taken nationally in 2007; it is not statistically valid at the 

national forest level, however, it can be used as an indicator of maintenance needs for the existing road 

system.

Environmental Consequences

Forest Plan and Other Regulatory Direction

All the action alternatives comply with the Forest Plan and the Transportation Rule. Additionally, roads 

analyzed for motorized mixed use were assessed for compliance with the California Vehicle Code (see 

Appendix J – Roads Analyzed for Motorized Mixed Use).

Public Safety

Direct and Indirect Effects

Prohibiting Cross Country Travel. Alternative 1 would continue to have unauthorized cross country 

travel on 754,066 acres. This would affect public safety of the off road traveler in that those risks and 

hazards of unknown situations continue to exist. All of the action alternatives prohibit cross country 

travel on 833,392 to 836,000 acres. Motorized travel would occur only on designated routes, NFTS roads 

and trails, receiving periodic maintenance. The periodic maintenance includes the identification and 

remediation of known hazards. It is common for the users of the designated routes to identify or remove

hazards such a fallen trees and rocks from the traveled way. Designated routes also have either been 

engineered and constructed utilizing safety standards or, at a minimum, have been reviewed for safety 

before having been added to the transportation system.

Additions to the NFTS. The new roads and trails proposed in Alternatives 2, 4, 5, 6, and 7 were 

evaluated for safety and compliance with design standards (see Appendix A, “Site Specific Road, Trail 

and Open Area Information,” for specific routes). None of the roads or trails was found to present an 

unacceptable safety risk. Likewise, none of the Maintenance Level 1 Roads reopened for motorized 

mixed use present an unacceptable safety risk, or does changing the season of use on roads or the 

prohibition on cross country travel. All roads proposed for additions would be managed as Maintenance 

Level 2 and as such not subject to the Highway Safety Act. Refer to Table 3.08-3 for a summary 

comparison of alternatives with respect to safety.
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Chapter 3: Affected Environment & Environmental Consequences – 3.08. Transportation

728 – Tahoe National Forest

Table 3.08-3. Summary comparison of alternatives with respect to public safety

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Miles of passenger car roads (Maintenance Level 3-5) 

changed to high clearance roads (Maintenance Level 2)

0 157.2 0 3.4 157.2 122.0 3.4

Additions to the NFTS 0 54.6 0 22.6 75.4 48.3 36.7

Maintenance Level 1 Roads Reopened to Motor Vehicles 0 0 0 0.1 93.4 11.4 1.1

Miles of Passenger Car Road with Change in Allowed 

Classes of Vehicles from “Highway Legal Only” to “All 

Vehicles” - By Approving Motorized Mixed Use (MMU)

0 241.5 0 3.4 241.5 130.8 3.4

Miles of passenger car roads with high crash severity 

Motorized Mixed Use (MMU)

0 174.1 0 0 174.1 4.1 0

Miles of passenger car roads with high crash probability 

Motorized Mixed Use (MMU)

0 32.0 0 0 32.0 0 0

Number of MMU roads consistent with California Vehicle 

Code Division 16.5, Combined Use

0 56 0 1 56 53 1

Number of MMU roads not consistent with California 

Vehicle Code Division 16.5, Combined Use

0 28 0 0 28 10 0

Establishment of motorized “Open Areas”: The establishment of 2,649 or 2,589 acres of “Open 

Areas” in Alternative 2 or 6 respectively would affect public safety in that the areas have been reviewed 

for safe use by motorized traffic. These “Open Areas” are not known to have health risks or unusual 

circumstances that pose safety concerns for prudent users. The other action alternatives would not 

establish “Open Areas” and do not affect public safety.

Change in Class of Vehicle from Approval of Mixed Use. Alternatives 2 and 5 present the greatest 

risks to public safety from mixed use crashes, as they contain the most miles where motorized mixed use 

would occur on the roads with higher crash severities, higher crash probabilities or both. Alternative 6 

follows with fewer roads proposed for motorized mixed use evaluated as having higher crash severities 

and probabilities. It also has fewer roads that are inconsistent with Combined Use of Division 16.5 OFFHIGHWAY VEHICLES of California Vehicle Code (CVC) than Alternatives 2 and 5. The remaining 

Alternatives, 1, 3, 4, and 7, all have less than 3.4 miles of road with a change in class from “Open to 

Highway Legal Vehicles Only” to “Open to All Vehicles.” (See Appendix J: Roads Analyzed for 

Motorized Mixed Use).

Change in Class of Vehicles from Reclassifying the Maintenance Level. Reclassifying passenger 

car roads to high clearance roads does not present a motorized mixed use safety risk in and of itself. By 

changing these roads, motorized mixed use would be allowed on roads where use previously was not 

designated. These roads were also analyzed for motorized mixed use. A road that is reclassified from 

passenger car (ML 3) to high clearance (ML 2) is no longer subject to the Highway Safety Act. (See 

Appendix J: Roads Analyzed for Motorized Mixed Use)

Changes in Season of Use: The proposed changes to the seasons of allowed use in Alternatives 4, 5, 

and 6 were not intended to serve as a safety measure designed to reduce accidents rates. The Forest does 

not have figures on accident rates related to weather conditions. It is likely that fewer accidents,

attributable to winter weather conditions would occur compared to Alternatives 1, 2, 3 and 7.
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Amendment to the Forest Plan. An amendment to the Forest Plan would not affect public safety in a 

meaningful or measurable way.

Cumulative Effects

The cumulative effects on public safety of all the reasonably foreseeable actions in Appendix H and 

the actions proposed in this EIS would maintain and improve public safety.

Affordability

Direct and Indirect Effects

All of the alternatives require approximately $10 million annually to fully maintain the designated 

motorized routes. See Table 3.08-4. Alternatives 1, 3, 4, and 7 cost the most to maintain at over $10.7

million. These alternatives have higher costs since fewer roads would be reclassified from Maintenance 

Level 3-5 to Maintenance Level 2 compared to Alternative 2, 5 and 6. Maintenance Level 3-5 roads

account for the major amount of the expense in these alternatives. Alternatives 2, 5, and 6 each cost 

approximately $9.5 million annually to maintain, or about $1.2 million less than the other alternatives due 

primarily from changing Maintenance Level 3-5 roads to Maintenance Level 2.

Changes in class of vehicles allowed on passenger car roads by permitting motorized mixed use could 

increase annual maintenance slightly on some roads. It is difficult to determine what user related 

maintenance is attributable to motorcycles and four-wheel drive vehicles by whether they are licensed for 

highway use or not.

Prohibiting Cross Country Travel. Alternative 1 would continue to have unauthorized cross country 

travel on 754,066 acres. This would not affect affordability/cost of maintenance of the existing NFTS 

roads and trails. However, costs are incurred by the Forest Service for the repair and prevention of 

unacceptable resource damage on unauthorized routes and cross country travel. The action alternatives 

would prohibit cross country travel on 833,392 to 836,000 acres, reducing use on 869 miles of known 

unauthorized routes and future user created routes. Prohibiting motorized cross country travel would 

increase traffic on the designated routes only slightly since that same traffic is already using the 

designated system, to large extent, to gain access to cross country locations. Prohibiting cross country 

travel in all the action alternatives would likely affect the affordability of the designated system slightly 

by increased user related maintenance costs. Cost incurred restoring and rehabilitating damage caused by

cross country travel, motorized use of unauthorized routes, and preventing additional damages would be 

reduced by a similar or greater amount.

Additions to the NFTS. Table 3.08-4 compares the cost maintaining the NFTS by alternative. The 

costs reflect changes to the system resulting from changes to maintenance levels, reopening Maintenance 

Level 1 roads, implementation costs and the mitigation costs listed in Appendix A, “Site Specific Road, 

Trail and Open Area Information,” for specific routes by each alternative.
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Table 3.08-4. Summary comparison of alternatives with respect to affordability of annual maintenance, 

implementation, and mitigations

Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Maintenance Costs by Miles of Roads

Closed, ML 1 567.1 567.1 567.1 567.0 473.7 555.7 566.0

High Clearance, ML 2 1492.8 1655.0 1492.8 1499.9 1748.4 1639.3 1497.3

Passenger Car, ML 3 522.4 365.2 522.4 519.0 365.2 400.4 519.0

Passenger Car, ML 4&5 196.0 196.0 196.0 196.0 196.0 196.0 196.0

NFTS roads

(total miles) 2778.3 2783.3 2778.3 2781.9 2783.2 2791.4.3 2778.3

Annual Road Cost $10,277,760 $8,754,444 $10,277,760 $10,248,897 $8,840,217 $9,116,553 $10,245,699

Maintenance Costs by Miles of Trails

High Clearance 4x4 133.9 158.1 133.9 139.4 178.5 156.4 150.8

ATV’s < 48” 25.5 29.9 25.5 28.4 44.2 38.8 28.9

Single Track Motorcycle 168.8 194.8 168.8 183.0 194.9 189.9 185.3

Motorized Trails 328.2 382.8 328.2 350.8 417.6 385.1 365.0

Annual Trail Cost $466,343 $543,623 $466,343 $497,130 $589,410 $540,735 $518,243

Annual Road and

Trail Cost Total

$10,744,103 $9,298,067 $10,744,103 $10,746,027 $9,429,627 $9,657,288 $10,763,942

Implementation Costs

Passenger car roads 

reclassified to ML 2

$0 $82,500 $0 $2,500 $82,500 $77,500 $2,500

MVUM Publication $0 $100,000 $100,000 $100,000 $100,000 $100,000 $100,000

MMU Implementation $0 $100,000 $0 $0 $100,000 $54,000 $0

Total Implementation 

Cost

$0 $282,500 $100,000 $102,500 $282,500 $231,500 $102,500

Mitigation Costs

Mitigations Costs from 

“Appendix A”

$0 $220,150 $0 $42,950 $219,500 $145,750 $145,700

Total Implementation

and Mitigation Costs

$0 $491,150 $100,000 $135,450 $510,500 $355,750 $238,200

Total estimated cost to 

implement and maintain 

annually (millions)

$10.74 $9.80 $10.84 $10.89 $9.93 $10.03 $11.01

Establishment of motorized “Open Areas”: The establishment of 2,649 or 2,589 acres of “Open 

Areas” in Alternative 2 or 6 respectively would not affect affordability of the transportation system. Open 

areas are not considered an element of NFTS roads or trails. The Forest Service would incur cost to 

delineate, administer, and maintain these areas. The other action alternatives would not establish “Open 

Areas” and do not affect affordability.

Change in Class of Vehicle from Approval of Mixed Use. Most of the costs for designating 

passenger car roads for motorized mixed use on roads (changing class of vehicles allowed) would be 

associated with signing, clearing sight distance in curves and surface grading. The typical signs used to 

alert drivers to “Share the Road,” would be placed at sufficient intervals to keep drivers aware and the 
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signs to delineate the extent of allowed motorized mix use. The estimated average cost to implement the

motorized mixed use on passenger car roads is $2,000 per road designated. Alternatives 2 and 5 would 

change the class of vehicles allowed on 50 passenger car roads. Alternative 6 would change the class of 

vehicles on 27 roads to allow mixed use. No roads would be changed with Alternatives 1, 3, 4, or 7.

Costs associated with producing the Motor Vehicle Use Map (MVUM) are primarily from labor, as 

the INFRA database would need to be updated and draft maps produced and edited. The Regional Office 

would pay for printing. 

Change in Class of Vehicles from Reclassifying the Maintenance Level. The key costs associated 

with reclassifying passenger car roads to high clearance roads are the signing, equipment and 

administrative costs to change the entrance strategy from accepting to discouraging passenger car travel. 

For this estimate, two signs were assumed to need replacing for every road; each sign costs about $300 to 

install and about $1,800 equipment and operator time to alter the road to high clearance. Also about $100 

administrative and data steward’s time would be needed to update the INFRA database. In total, 

approximately $2,500 would be needed to make the change from passenger car to high clearance road for 

each road. Alternatives 2 and 5 would reclassify 33 ML 3 roads to ML 2. Alternative 6 would reclassify 

31 roads. Only one road would be reclassified in Alternatives 4 and 7, and none in Alternatives 1and 3.

See Appendix J: Roads Analyzed for Motorized Mixed Use.

All of the roads proposed for reclassification from suitable for passenger cars to high clearance 

vehicles are Objective Maintenance Level 3 roads. Except for several staging area and campground roads 

these are forest collector routes or primary forest roads. These roads are not only maintained to provide 

passenger car access to destinations but are maintained at these higher levels for efficiency of use for 

activities such as commercial haul and fire suppression access. These roads have higher levels of capital 

investments in construction of the road prism and surfacing compared to the typical high clearance forest 

road. Some degree of loss in this capital investment is likely over time resulting from lower maintenance 

effort expended to maintain the roads at the ML 2 standard. The trend would be corresponding losses in 

efficiency in these roads resulting in higher user costs and higher cost to return the roads to original 

condition for safe use during scheduled activities.

Eighteen of these same primary roads in Alternatives 2, 5 and 6 that would be reclassified to a lower 

maintenance level have cost share easements. This where a private company holds a title easement, has 

shared in the construction costs and participates in the maintenance costs of these roads. These roads

would experience the same trends in loss of capital investment and increased user costs.

Changes in Season of Use. Wet weather seasonal restrictions on roads and trails in Alternatives 4, 5 

and 6 have potential to decrease road maintenance costs compared to Alternatives 1, 2, 3, and 7. The 

amount potential cost reduction is difficult to quantify. User generated maintenance costs could be 

reduced by increasing the interval of scheduled maintenance items such as grading the surface and 

repairing waterbars when roads and trails receive less damaged caused by wet weather use. Traffic drops 

off considerably once winter snow blankets the forest and vehicles no longer have access to most of the 

road and trail system. The season of allowed use in Alternatives 4, 5, and 6 coincides with the winter slow 
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732 – Tahoe National Forest

down in traffic. Ill-timed traffic on a saturated road can cause damage that is costly to repair and increase 

the frequency of maintenance required whether or not it occurs during a wet weather restriction.

Amendment to the Forest Plan. An amendment to the Forest Plan to lift seasonal traffic restrictions 

would potentially result in a very slight increase in cost of maintenance on 8.6 miles of NFTS roads. The 

increase in cost would be the result of an increase in time motorized traffic is allowed to use these 8.6 

miles of roads in Alternatives 2, 5, and 6. Motorized traffic would be allowed on 8.6 miles of 

Maintenance Level 2 for two additional months each year in Alternatives 5 and 6, and for three additional 

months each year in Alternative 2. The potential increase in maintenance cost would be the result of an 

increased maintenance interval of scheduled traffic generated maintenance of items such as waterbars, 

ditches, or drainage dips.

Cumulative Effects

The cumulative effects on affordability of all the reasonably foreseeable actions in Appendix H and the 

actions proposed in this EIS would have only minor affect to the overall affordability of the forest 

transportation system. 

Lower overall maintenance costs are seen in the alternatives that reclassify the maintenance of 

passenger car roads to lower standards for high clearance vehicles and by imposing a season of use. The 

more miles of road reclassified to a lower standard, the lower the overall maintenance cost. Where there 

are savings in the projected overall annual maintenance cost in Alternatives 2, 5 and 6 compared to 

Alternatives 1, 3, 4 and 7, those saving would likely be offset by: the increased costs to return these roads 

to the higher maintenance standards during scheduled activities, increased user costs due to decreased 

efficiency (slower travel and higher vehicle repair cost), the increased mileages added to the system in 

those alternatives, cost of mitigations and implementation, and potential loss of capital investment in road 

surfacing. 

Summary of Effects Analysis across All Alternatives

Table 3.08-5 summarizes the effects analysis for the transportation environment by ranking each 

alternative regarding how well it provides for each of the indicators. This summary is not meant to convey 

that the indicators are equal in importance. The following rankings were used: A score of 7 indicates the 

alternative has the least impact for the transportation environment to the indicator. A score of 1 indicates 

the alternative has the most impact for the transportation environment related to the indicator. A score of 0 

indicates the indictor does not apply.

Table 3.08-5. Comparison of Effects to Transportation

Indicator Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Affordability – Annual Maintenance 4 7 3 2 6 5 1

Affordability – Implementation 7 1 6 5 2 3 4

Safety 6 2 7 5 1 3 4

Average 5.7 3.3 5.3 4.0 3.0 3.7 3.0
Chapter 3.09 

Inventoried 

Roadless Areas & 

Special Areas 

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Tahoe National Forest – 733

3.09. Inventoried Roadless Areas & Special Areas ____________

This chapter describes the affected environment and environmental consequences for Inventoried 

Roadless Areas (IRAs) and Special Areas on Tahoe National Forest. IRAs are roadless areas identified in 

the second Roadless Area Review and Evaluation (RARE II). Special Areas are Forest Plan management 

area land allocations that include Wilderness, Experimental Forests, Wild and Scenic Rivers, Research 

Natural Areas (RNA), and Special Interest Areas (SIA). In addition, this section will review the effects of 

the alternatives on Citizen Inventoried Roadless Areas (CIRAs) identified by the California Wilderness 

Coalition.

Analysis Framework: Statute, Regulation, Forest Plan

and Other Direction

The Forest Service conducted RARE II from 1977 to 1979 studying 11 roadless areas (171,328 acres) on 

the Tahoe National Forest for their wilderness values. The California Wilderness Act of 1984 designated

25,680 of those acres as the Granite Chief Wilderness. The Forest addressed management direction for

IRAs in the 1990 Forest Plan. Information about IRAs on the Tahoe NF can be found in Volume 2 of the 

Final Environmental Impact Statement for the Forest Service Roadless Area Conservation Project, 

November 2000. That information can be accessed at the following website:

In 2001, the California Wilderness Coalition (CWC) completed its own inventory of potential 

wilderness areas on California public lands. For the purpose of this analysis, these areas will be referred 

to as citizen inventoried roadless areas (CIRAs). Restrictions on road construction and reconstruction 

specified in the 2001 Roadless Area Conservation Rule apply only to those areas within agency-identified 

IRAs. A separate analysis has been conducted to compare the effects of the alternatives on CIRAs. CIRAs 

located within agency-identified IRAs will not be analyzed separately.

http://fs.usda.gov/Internet/FSE_DOCUMENTS?fsmrs_072591.pdf

There are three RNAs located on Tahoe National Forest. Research Natural Areas are managed to 

maintain select vegetative, aquatic, and/or geologic elements in natural conditions. Forest Service Manual 

(FSM) 4063.3 provides protection against any activities that directly or indirectly modify ecological 

processes (USDA 2005b). RNAs, established for research and study purposes, are a discrete land area 

large enough to represent a specific natural ecosystem. RNAs are important because they provide 

benchmarks for comparison of present and future management of the National Forests and will prove to 

be an invaluable asset in the future.

The general provisions of the Organic Administration Act of 1897 and the Forest and Rangeland 

Renewable Resource Research Act of 1978 authorize the designation of Experimental Forests.

Experimental Forests provide lands for conducting research and development that serves as a basis for the 

management of forests and grasslands. There are two Experimental Forests located within the Tahoe 

National Forest.

Forest Plan direction for the North Fork American Wild River is to manage the designated river 

corridor in accordance with Public Law 95-625, which documents the Congressional designation of the 
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734 – Tahoe National Forest

river. Forest Service direction for proposed Wild and Scenic rivers is to maintain and enhance the Wild 

and Scenic River characteristics and manage the same as designated Wild and Scenic Rivers. Four river 

corridors within the Tahoe NF have been recommended for designation as Wild and Scenic Rivers (W&S 

Study Report, May 1999). Proposed Wild and Scenic River corridors include sections of Sagehen Creek, 

Canyon Creek, North Yuba River, and the Lower South Yuba River. Management policy for the four 

proposed Wild and Scenic rivers is guided by FSM 2354.21, which directs the Forest Service to “manage 

wild and scenic river study areas to protect existing characteristics through the study period and until 

designated or released from consideration.”

There are seven Special Interest Areas (SIAs) on the Tahoe National Forest. Special Interest Areas are 

established to protect , and where appropriate, foster public use, study, and enjoyment of areas with 

scientific, scenic, historical, geological, botanical, zoological, paleontological, or other special 

characteristics. Management direction for each SIA is contained in the 1990 Tahoe National Forest Land 

and Resource Management Plan (Forest Plan).

Effects Analysis Methodology

Assumptions Specific to Inventoried Roadless Areas and Special Areas

• All of the unauthorized routes and Maintenance Level 1 roads being considered for motorized use 

are currently available for motorized use because nothing prohibits such use. The effect of this 

motorized use is part of the existing situation.

• Granite Chief Wilderness is not affected by the proposed action or any alternative as motorized

activity is prohibited in that area under all alternatives.

• No unauthorized motor vehicle routes within RNAs would be added to the NFTS in any 

alternative.

• No unauthorized motor vehicle routes in designated Wild and Scenic River corridors would be 

added to the NFTS in any alternative

• No vehicle class changes are proposed in designated Wild and Scenic Rivers in any alternative.

Data Sources

• Tahoe National Forest Land and Resources Management Plan (Forest Plan)

• Tahoe National Forest Geographic Information Systems layers (GIS)

• Appendix G of the Forest Plan FEIS

• Two Westside Rivers Wild and Scenic River Study Report, FEIS, 1999

Roadless and Special Area Indicators

The following indicators are used to identify effects that may occur in IRAs and/or Special Areas as a 

result of implementing the No Action Alternative and action alternatives: 

Roadless Area Characteristics: the following values or features often characterize Inventoried 

Roadless Areas (66 Federal Register 9, January 12, 2001; p. 3245):

• High quality or undisturbed soil, water, and air: These three key resources are the foundation 

upon which other resource values and outputs depend. Healthy watersheds catch, store, and safely 
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Tahoe National Forest – 735

release water over time, protecting downstream communities from flooding; providing clean water 

for domestic, agricultural, and industrial uses; helping maintain abundant and healthy fish and 

wildlife populations; and are the basis for many forms of outdoor recreation.

• Sources of public drinking water: National Forest System lands contain watersheds that are 

important sources of public drinking water. Maintaining these areas in a relatively undisturbed 

condition saves downstream communities millions of dollars in water filtration costs.

• Diversity of plant and animal communities: Roadless areas are more likely than roaded areas to 

support greater ecosystem health, including the diversity of native and desired non-native plant 

and animal communities due to the absence of disturbances caused by roads and accompanying 

activities. Inventoried Roadless Areas also conserve native biodiversity by serving as a bulwark 

against the spread of non-native invasive species.

• Habitat for threatened, endangered, proposed, candidate, and sensitive species and for those 

species dependent on large, undisturbed areas of land: Roadless areas function as biological 

strongholds and refuges for many species.

• Primitive, Semi-Primitive Non- Motorized, and Semi-Primitive Motorized recreation 

opportunities: Roadless areas often provide outstanding dispersed recreation opportunities such 

as hiking, camping, hunting, fishing, Nordic skiing and canoeing. While they may have many 

wilderness-like attributes, unlike Wilderness, mountain bikes and other mechanized uses are often 

allowed.

• Reference landscapes: Knowledge about the effects of management activities over long periods 

of time and on large landscapes is very limited. Reference landscapes of relatively undisturbed 

areas serve as a barometer to measure the effects of development on other parts of the landscape. 

• Natural appearing landscapes with high scenic quality: High quality scenery, especially 

scenery with natural-appearing landscapes, is a primary reason that people choose to recreate.

• Traditional cultural properties and sacred sites: Traditional cultural properties are places, sites, 

structures, art or objects that played an important role in the cultural history of a group. Sacred 

sites are places with special religious significance to a group. Traditional cultural properties and 

sacred sites may be eligible for protection under the National Historic Preservation Act. However, 

many of them have not yet been inventoried, especially those that occur in IRAs. 

• Other locally identified unique characteristics: IRAs areas may offer other locally identified 

unique characteristics and values. Examples include uncommon geological formations, valued for 

their scientific and scenic qualities, or unique wetland complexes.

CIRA Values: Citizen Inventoried Roadless Areas (CIRAs) were identified by the California 

Wilderness Coalition for their values as potential additions to the National Wilderness Preservation 

System. The effects on CIRAs will be disclosed in the alternatives by using the roadless and wilderness 

characteristics identified above.
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736 – Tahoe National Forest

Wilderness Characteristics: The principal wilderness characteristics as described in Forest Service 

Handbook (FSH) 1909.12 that follow are generally, but not necessarily, listed in order of importance or 

desirability (USDA, 2007).

• Natural: ecological systems are substantially free from the effects of modern civilization and 

generally appear affected primarily by forces of nature. Effects of modern civilization include:

§ The presence of non-native species that alter the composition of natural plant and animal 

communities (such as non-native plants, animals, fish, livestock, invertebrates, and pathogens).

§ Developments that degrade the free-flowing condition or rivers and streams (such as dams or 

other water diversions and impoundments).

§ The presence of light pollution that degrades night sky quality and night sky quality related 

values.

§ The presence of pollutants that degrade water quality and the health of ecosystems, plant 

communities, and plant species that are rare or at risk.

• Undeveloped: The degree to which the area is without permanent human improvements or human 

habitation. A measure of undeveloped is the level of human occupation and modification including 

evidence of structures, construction, habitations, or other forms of human presence, use and 

occupation.

• Outstanding opportunities for solitude or primitive and unconfined recreation: The area 

provides solitude or primitive and unconfined types of recreation including a wide range of 

experiential opportunities such as: physical and mental challenge, adventure and self-reliance, 

feelings of solitude, isolation, self-awareness and inspiration. Solitude is the opportunity to 

experience isolation from sights, sounds, and the presence of others from the developments and 

evidence of humans. The opportunity to experience isolation from the evidence of humans, to feel a 

part of nature, to have a vastness of scale, and a degree of challenge and risk while using outdoor 

skills are measures of primitive and unconfined recreation.

• Special features and values: The area provides other values such as those with ecologic, geologic, 

scientific, educational, scenic, historical, or cultural significance. Examples include unique fish and 

wildlife species, unique plants or animal communities, connectivity, potential or existing research 

natural areas, outstanding landscape features and significant cultural resource sites.

Experimental Forest Values: Experimental Forest values on the Tahoe National Forest (TNF) are 

related to their suitability as areas for research on the effects of forest management on wildlife and 

impacts to water quality, timing, and yield.

Wild and Scenic River Values: For a river to be eligible for Wild and Scenic River designation it 

must be free-flowing and, with its adjacent land area, must possess one or more outstandingly remarkable 

values (Federal Register 1982). Outstandingly remarkable values are specific to each river segment and

may include cultural, ecologic, fish, geologic, historic, scenic, recreation, wildlife or other special and 

unique features (USDA 1991b).
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Research Natural Area Values: RNA values are specific to individual RNAs and may include 

selected aquatic, geologic or vegetation elements.

Special Interest Area Values: SIA values are specific to each SIA and may include unique botanic, 

cultural, geologic, scenic, historic and memorial features.

Roadless and Special Areas Methodology by Action

The effects of each alternative are described below according to five actions common to all 

alternatives:

1. Cross-country Travel: Prohibition of cross country motor vehicle travel is included in all 

alternatives except Alternative 1 (no action).

2. Additions to the NFTS: The amount unauthorized routes proposed as additions to the NFTS 

within IRAs vary by alternative. 

3. Establishment of Motorized “Open Areas”: No “Open Areas” are being proposed for 

establishment within IRAs or special areas in any alternative 

4. Changes to the Existing NFTS: includes changes to vehicle class and season of use on the 

existing NFTS. Impacts caused by changes to vehicle class and season of use on the existing 

NFTS are described generally by alternative.

5. Amendments to Forest Plan: Not applicable to IRAs or special areas.

Inventoried Roadless Areas: Affected Environment

Tahoe National Forest has eleven IRAs totaling 171,328 acres (Tahoe NF, GIS data), excluding private 

lands located within the IRA boundaries. The names and acres of each IRA are listed in Table 3.09-1.

Table 3.09-1. Inventoried Roadless Areas – Tahoe National Forest

Bald Mountain (extends onto the Humboldt-Toiyabe NF) 5,834

Castle Peak 15,738

Duncan Canyon 9,253

East Yuba 10,805

Granite Chief (Granite Chief Wilderness acreage included) 31,297

Grouse Lakes (Grouse Lake vehicular closure included) 19,271

Lakes (Basin) (extends onto the Plumas NF) 557

Middle Yuba 7,884

North Fork American River (NFAR Wild River included) 43,374

North Fork of the Middle Fork American River 11,257

West Yuba (extends onto the Plumas NF) 16,058

The character and amount of roads, private land and motorized trails varies greatly between the listed 

IRAs. Castle Peak and Duncan Canyon IRAs both inherited roads through land purchase or exchange that 

were built while those lands were in private ownership. Middle Yuba IRA contains extensive private land 
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738 – Tahoe National Forest

parcels that are accessed by roads. East and West Yuba IRAs contain some primitive 4WD routes, as well 

as several NFTS and unauthorized motorcycle trails. The North Fork American River IRA has one road 

accessing private land and two minor unauthorized routes within the IRA boundary. Each of the 

Inventoried Roadless Areas is described in more detail below.

Bald Mountain IRA

The Bald Mountain IRA is located east of the Sierra Nevada Range on Sierraville Ranger District.

Approximately 1,061 acres of this IRA has been established as a Research Natural Area (RNA). A small 

portion of the IRA is in private ownership near the northern boundary of the area.

Recreation use is low and consists mostly of hunting, hiking, and OHV use. There are a number of 

unimproved roads, trails, and dispersed recreation locations within the area. The primary attraction of the 

area is the good hunting which may be found there.

In the Forest Plan, the Bald Mountain IRA was allocated to the following Management Prescriptions; 

#5 Research and Botanical (15%) and #13 Timber an Range (85%). Table 3.09-2 shows the mileage of 

roads and trails in the Bald Mountain IRA by category.

Table 3.09-2. Roads and Trails in the Bald Mountain Inventoried Roadless Area

Road and Trail Category Season of Use Miles

Cross country travel (acreage open to motorized use: 4,490)

Unauthorized routes

Closed NFTS roads receiving some motorized use

Not Applicable 3.6

1.2

NFTS Roads open to all vehicles All Year 4.6

State, County or other jurisdiction roads All Year 0.8

NFTS Trails open only to non-motorized users All Year 1.8

Total Motorized Open to Public 10.2

*Numbers may not add up due to rounding.

Castle Peak IRA

The Castle Peak IRA is located along the crest of the Sierra Nevada between Castle Peak on the south and 

Mt. Lola on the north. The area is characterized by sparse vegetation, high elevations, steep, rocky terrain, 

and shallow soils. Nearly one-half of the area is in private ownership. The primary private landowner 

conducts timber management activities on their property. Logging has occurred on private lands in the 

White Rock area. No major mining activity has occurred in the area and there is little mineral potential. 

Several timber sales have been completed in the area.

Castle Peak and its surroundings are among the most scenic areas on the Tahoe National Forest. This 

is due to the rugged topography, presence of vistas of lakes, rock outcrops, etc. The IRA is popular for 

hiking in the summer and sees heavy cross-country skiing and snowmobile use in the winter.

Most of the IRA is open to OHV use on designated routes only. The general lack of OHV routes, 

however, contributes to low use except for snowmobiling in winter. There are several non-motorized trails 

through the area, including a portion of the Pacific Crest Trail, but few roads. 
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In the Forest Plan, this IRA was allocated to the following Management Prescriptions; #3 Dispersed 

Motorized Recreation (93%) and #11 Winter Recreation (7%). Table 3.09-3 shows the amount of roads 

and trails in the Castle Peak IRA by category.

Table 3.09-3. Roads and Trails in the Castle Peak Inventoried Roadless Area

Road and Trail Category Season of Use Miles

Cross country travel (acreage open to motorized use: 15,738)

Unauthorized routes 

Closed NFTS roads receiving some motorized use

Not Applicable 9.3

.8

NFTS Roads open to all vehicles Open Year Around 3.4

NFTS Roads open to all vehicles Seasonal Closure 0.5

NFTS Trails open to high clearance trail vehicles Open Year Around 1.1

Roads/trails on private land Open Year Around 3.6

NFTS Trails open only to non-motorized users Open Year Around 14.8

NFTS Trails open only to hikers and equestrians (No mountain bikes allowed) Open Year Around 6.9

Total Motorized Open to Public 18.7

*Numbers may not add up due to rounding.

Duncan Canyon IRA

Duncan Canyon IRA is situated in eastern Placer County on the American River Ranger District. It 

includes portions of the State Game Refuge that encompasses recreation facilities located at French 

Meadows Reservoir.

The major feature of the area is the rugged Duncan Canyon. Red Star Ridge forms the eastern and 

southern boundary of the area while Little Bald Mountain and Sunflower Hill mark the western boundary. 

The northern boundary is the French Meadows – Soda Springs Road. One section (640 acres) near 

Sunflower Hill is in private ownership. In 1979, the Erickson Lumber Company constructed a road under

special-use permit to access their lands. The company plans to conduct timber management activities on 

their lands. 

Hunting, fishing and hiking are the principal recreation uses of this area. The Tevis Cup Loop passes 

through the area along Red Star Ridge. This trail is used for an annual endurance ride and run. The main 

attraction is Little Robinson Valley located in the western portion of the IRA. 

In the Forest Plan, this IRA was allocated to the following Management Prescriptions; #2 Dispersed 

Non-Motorized Recreation (7%) and #15 Visual and Timber and (93%). Table 3.09-4 shows the amount 

of roads and trails in the Duncan Canyon IRA by category.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

740 – Tahoe National Forest

Table 3.09-4. Roads and Trails in the Duncan Canyon Inventoried Roadless Area

Road and Trail Category Season of Use Miles

Cross country travel (acreage open to motorized use: 8,641)

Unauthorized routes 

Closed NFTS roads receiving some motorized use

Not Applicable 4.1

4.8

NFTS Roads open to all vehicles All Year 0.1

NFTS Roads open to all vehicles Seasonal Closure 0.2

NFTS Trails open to motorcycles Seasonal Closure 0.5

NFTS Trails open to motorcycles All Year 11.2

State, County or other jurisdiction roads All Year 0.0

NFTS Trails open only to non-motorized users All Year 2.5

Motorized Open to Public 20.9

*Numbers may not add up due to rounding.

East Yuba IRA

The East Yuba IRA is located on Yuba River Ranger District, bordering Plumas National Forest in the 

Lavezzola Creek drainage. The western boundary is roaded from the “A” Tree Road through Cowell Mine 

into Empire and Lavezzola drainages. The eastern portion of the area is accessed by OHV routes that 

receive heavy use.

The Pacific Crest National Scenic Trail crosses the northern portion of the area. There are numerous 

routes constructed for mining during the past 100 years. Active prospecting and exploration occurs within 

the IRA, such as at the Four Hills Mine located in the northeast portion.

In the Forest Plan, this IRA was allocated to the following Management Prescriptions; #3 Dispersed 

Motorized Recreation (48%), #13 Timber and Range (20%), and #15 Visual and Timber (32%). Table 

3.09-5 shows the mileage of roads and trails in the East Yuba IRA by category.

Table 3.09-5. Roads and Trails in the East Yuba Inventoried Roadless Area

Road and Trail Category Season of Use Miles

Cross country travel (acreage open to motorized use: 10,193)

Unauthorized routes Not Applicable 9.4

NFTS Roads open to highway legal vehicles only All Year 0.0

NFTS Trails open to high clearance vehicles Seasonal Closure 3.4

NFTS Trails open to high clearance vehicles All Year 14.5

NFTS Trails only open to motorcycles All year 14.5

Roads/trails on private land Not Applicable 1.0

NFTS Trails open only to non-motorized users All Year 0.9

NFTS Trails open only to hikers and equestrians (No mountain bikes allowed) All Year 1.6

Total Motorized Open to the Public 42.9

*Numbers may not add up due to rounding.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

Tahoe National Forest – 741

Granite Chief IRA

The Granite Chief IRA is located adjacent to the western watershed boundary of Lake Tahoe on the 

Truckee and American River Ranger Districts. The total acreage of Granite Chief IRA within Tahoe NF is 

31,297 acres. The California Wilderness Act of 1984 designated 25,680 acres of this IRA as the Granite 

Chief Wilderness.

The area is used primarily by hikers, fishermen, and hunters. The major attractions of this area are 

high, rugged granitic cliffs and broad glaciated valleys found in the northern portion of the IRA. The 

numerous streams distributed throughout the area provide opportunities for hiking, camping, and 

sightseeing. The abundance of game and non-game animals also attracts a large number of visitors. 

Portion of a State Game Refuge extend into the area and consists of all of Picayune Valley, Little 

American Valley, and the west slope of Mt. Mildred.

In the Forest Plan this roadless area was allocated to the following Management Prescriptions; #1 

Wilderness (74%), #2 Dispersed Non-Motorized Recreation (18%), #5 Research and Botanical (2%) and 

#13 Timber an Range (6%). Table 3.09-6 shows the amount of roads and trails in the Granite Chief IRA 

by category.

Table 3.09-6. Roads and Trails in the Granite Chief Inventoried Roadless Area

Road and Trail Category Season of Use Miles

Cross Country Travel (acreage open to motorized use: 1,930) 

Unauthorized routes Not Applicable 0.3

Roads/trails on private land Not Applicable 0.7

Trails open only to hikers and equestrians (No mountain bikes allowed) All year 51.7

Total Motorized Open to Public 1.1

*Numbers may not add up due to rounding.

Grouse Lakes IRA

Grouse Lakes IRA is located in western Nevada County on the Yuba River Ranger District. The area 

includes numerous lakes and streams that are the focus of public recreation use. Over one-half of the 

Grouse Lakes is in private ownership. The primary owner is Sierra Pacific Industries. The company 

conducts timber management activities on their lands.

Dispersed recreation (hunting, fishing and hiking) is the primary use of the area. The majority of the 

area prohibits motor vehicle use, with a few exceptions. One exception is a small segment of the Meadow 

Lake jeep road which passes through a portion of the motor vehicle closure area. The area south of 

Fordyce Creek is open to OHV use with moderate to heavy use of Red Mountain and Signal Peak jeep 

trails.

In the Forest Plan this roadless area was allocated to the following Management Prescriptions; #2 

Dispersed Non-Motorized Recreation (90%), #3 Dispersed Motorized Recreation (7%) and #13 Timber 

an Range (3%). Table 3.09-7 shows the mileage of roads and trails in the Grouse Lakes IRA by category.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

742 – Tahoe National Forest

Table 3.09-7. Roads and Trails in the Grouse Lakes Inventoried Roadless Area

Road and Trail Category Season of Use Miles

Cross country travel (acreage open to this motorized use: 6,081)

Unauthorized routes 

Closed NFTS roads receiving some motorized use

Not Applicable 3.3

.2

NFTS Roads open to highway vehicles only All Year 0.0

NFTS Roads open to all vehicles All Year 5.3

NFTS Trails open to high clearance trail vehicles All Year 9.1

Roads/trails on private land Not Applicable 2.7

NFTS Trails open only to non-motorized users All Year 27.2

Total Motorized Open to Public 20.5

*Numbers may not add up due to rounding.

Lakes Basin IRA

The Lakes Basin IRA is situated on both the Plumas and Tahoe National Forests. The portion of the IRA

on the TNF is very rocky and sparsely vegetated. The southern boundary follows a jeep road from the 

vicinity of Oakland Pond to Snake Lake then extends westerly to the private lands near Hawley Lake. 

These private lands form the western boundary.

The Pacific Crest Trail (PCT) passes through the area near the administrative boundary between the 

Plumas NF and Tahoe NF. OHV use occurs on several jeep roads adjacent to the area, but overall the 

steep terrain of the TNF portion limits recreation use.

In the Forest Plan, this IRA was allocated to Management Prescription #3 Dispersed Motorized 

Recreation (100%). Table 3.09-8 shows the amount of roads and trails in the Lakes Basin IRA by 

category.

Table 3.09-8. Roads and Trails in the Lakes Basin Inventoried Roadless Area

Road and Trail Category Season of Use Miles

Cross country travel (acreage open to motorized use: 557)

Unauthorized routes Not Applicable 0.1

NFTS Trails open to high clearance trail vehicles Open Year Around 0.4

NFTS Trails open only to hikers and equestrians (No mountain bikes allowed) Open Year Around 2.0

Previously decommissioned roads Closed 1.8

Total Motorized Open to Public 0.5

*Numbers may not add up due to rounding.

Middle Yuba IRA

The Middle Yuba IRA is situated on the Middle Yuba River, primarily on the Yuba River Ranger District.

There is a small portion on the eastern edge in the Sierraville Ranger District. The entire IRA is located 

within an area of alternate land ownership pattern. Over 40 percent of this area is privately owned. Most 

of the private land would be receive intensive timber management activities. The area is also included in 

cost-share supplements.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

Tahoe National Forest – 743

There are some active mining claims in this area. There is abundant evidence of historic mining 

throughout the area, such as mineshafts, buildings, primitive roads, and tailings. Mining activity continues 

today, particularly placer mining. Recreation use of the IRA includes fishing and river use associated with 

suction dredging, sluicing, and panning for gold.

In the Forest Plan, this IRA was allocated to the following Management Prescriptions; #3 Dispersed 

Motorized Recreation (76%) and #13 Timber and Range (24%). Table 3.09-9 shows the mileage of roads 

and trails in the Middle Yuba IRA by category.

Table 3.09-9. Roads and Trails in the Middle Yuba Inventoried Roadless Area

Road and Trail Category Season of Use Miles

Cross country travel (acreage open to motorized use: 7,884)

Unauthorized routes

Closed NFTS roads receiving some motorized use

Not Applicable 4.8

1.2

NFTS Roads open to highway legal vehicles only All Year 0.6

NFTS Roads open to all vehicles All Year 6.6

NFTS Trails open to high clearance trail vehicles All Year 0.7

State, County or other jurisdiction roads All Year 0.1

Roads/trails on private land Not Applicable 15.4

Total Motorized Open to Public 29.4

*Numbers may not add up due to rounding.

North Fork American River IRA

The North Fork American River IRA is situated on both sides of the North Fork of the American River. 

The North Fork of the American Wild River corridor is included within the IRA. The area extends from 

the western forest boundary near Giant Gap to approximately 11⁄2 miles east of Heath Springs, and is 

located with the American River, Truckee, and Yuba River Ranger Districts.

Hiking, fishing, and hunting are the primary recreation uses for the area. The main attractiveness of 

this area is the North Fork American Wild River, which is protected under the Wild River Act. Other areas 

include the high-elevation lakes in the Loch Leven area, which are sensitive to heavy, extended use by 

man. National Forest System lands surrounding the area are primarily managed for vegetation

management.

In the Forest Plan, this IRA was allocated to the following Management Prescriptions; #2 Dispersed 

Non-Motorized Recreation (48%), #3 Dispersed Motorized Recreation (17%), #5 Research and Botanical 

(2%), #6 Wild River (17%) and #13 Timber and Range (16%). Table 3.09-10 shows the mileage of roads 

and trails in the North Fork American River IRA by category.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

744 – Tahoe National Forest

Table 3.09-10. Roads and Trails in the North Fork American River Inventoried Roadless Area

Road and Trail Category Season of Use Miles

Cross country travel (acreage open to motorized use: 15,562)

Unauthorized routes and 

Closed NFTS roads receiving some motorized use

Not Applicable 1.2

1.1

NFTS Roads open to highway legal vehicles only All Year 0.1

NFTS Roads open to all vehicles Seasonal Closure 0.1

NFTS Roads open to all vehicles All Year 1.1

NFTS Trails open to motorcycles All Year 2.3

NFTS Trails open only to hikers and equestrians (No mountain bikes allowed) All Year 0.0

Roads and trails on private land All Year 3.1

Total Motorized Open to Public 9.0

*Numbers may not add up due to rounding.

North Fork of the Middle Fork of the American River IRA

The North Fork of the Middle Fork of the American River IRA is located in Placer County on the American 

River Ranger District between Mosquito Ridge and the Foresthill Divide. The area is characterized by steep

and rugged canyons and the major attraction is the North Fork of the Middle Fork of the American River. 

Only 500 acres are in private ownership. Mining has been an important activity in the area since the 

early days of the Gold Rush and numerous active mines are located in the area. Recreation use is low and

primarily involves hunting, fishing, and hiking. Virtually all of the area is open to OHV use, but the steep 

topography and lack of many roads limits use.

In the Forest Plan, this IRA was allocated to the following Management Prescriptions; #3 Dispersed 

Motorized Recreation (90%) #5 Research and Botanical (2%), #7 Wildlife (5%) and #8 Visual (3%).

Table 3.09-11 shows the amount of roads and trails in the North Fork of the Middle Fork American River 

IRA by category.

Table 3.09-11. Roads and Trails in the North Fork of the Middle Fork American River IRA

Road and Trail Category Season of Use Miles

Cross country travel (acreage open to motorized use: 11,175)

Unauthorized routes 

Closed NFTS roads receiving some motorized use

Not Applicable 1.2

.1

NFTS Roads open to highway legal vehicles only Open Year Around 0.0

NFTS Roads open to all vehicles Seasonal Closure 0.3

NFTS Roads open to all vehicles Open Year Around 1.1

NFTS Trails open to motorcycles Seasonal Closure 2.3

NFTS Trails open to high clearance trail vehicles Open Year Around 0.6

NFTS Trails open to motorcycles Open Year Around 12.5

NFTS Trails open only to hikers and equestrians (No mountain bikes allowed) Open Year Around 0.0

Total Motorized Open to Public 18.2

*Numbers may not add up due to rounding.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

Tahoe National Forest – 745

West Yuba IRA

The West Yuba IRA is situated north of Downieville and west of Craycroft Ridge in the Rattlesnake Creek 

drainage; portions of this IRA are located within Plumas National Forest.

The main attractions to the area are the stream bottoms and mountain peaks that create a variety of 

scenery. Hunting, hiking, and fishing are the primary recreation uses of the area. OHV use is also a very 

popular recreation activity on the existing network of roads and trails located within the IRA. National 

Forest Systems lands surrounding the West Yuba area are primarily managed for timber production, and 

heavily prospected and mined for valuable minerals.

In the Forest Plan this roadless area was allocated to the following Management Prescriptions; #3 

Dispersed Motorized Recreation (30%), #13 Timber and Range (30%) and #15 Visual & Timber (40%).

Table 3.09-12 shows the amount of roads and trails in the West Yuba IRA by category.

Table 3.09-12. Roads and Trails in the West Yuba Inventoried Roadless Area

Road and Trail Category Season of Use Miles

Cross Country Travel (acreage open to motorized use: 16,058)

Unauthorized routes 

Closed NFTS roads receiving some motorized use

Not Applicable 9.4

1.8

NFTS Roads open to all vehicles All Year 6.0

NFTS Trails open to high clearance trail vehicles All Year 8.2

NFTS Trails open to motorcycles All Year 9.7

Roads/trails on private land Not Applicable 0.6

Total Motorized Open to Public 35.7

*Numbers may not add up due to rounding.

Inventoried Roadless Areas: Environmental Consequences

In the following section, each IRA will be listed and environmental consequences described for the action

alternatives. Tables showing differences between the action alternatives are only included for those IRAs 

with substantial changes between alternatives. The effects of the No Action Alternative will be described 

first for all IRAs.

Alternative 1 (No Action)

Direct and Indirect Effects

Cross Country Travel: The No Action Alternative could reduce roadless character in each IRA because

cross country travel by motor vehicles would be allowed to continue on 98,309 acres of IRAs currently 

open to motorized use on Tahoe NF. Motor vehicle travel is already prohibited on 73,019 acres of lands 

being managed for primitive and semi-primitive non-motorized recreation use within the affected IRAs. 

Under Alternative 1, 46.7 miles of unauthorized routes and 11.3 miles of closed NFTS roads would 

continue to have some motor vehicle use in Inventoried Roadless Areas.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

746 – Tahoe National Forest

Increased noise generated by motor vehicles and more evidence of human activity due to crosscountry travel with continued route proliferation would alter the following roadless and wilderness 

characteristics:

• High quality or undisturbed soil, water and air would be degraded.

• Sources of public drinking water would be at higher risk.

• Diversity of plant and animal communities would be diminished.

• Habitat for threatened, endangered, proposed, candidate and sensitive species and for those species 

dependent on large, undisturbed areas of land would be degraded.

• Primitive and Semi-Primitive Non-Motorized recreation opportunities would be adversely 

impacted. 

• Natural appearing landscapes with high scenic quality would be adversely impacted.

• Natural ecological systems would be adversely impacted.

• The degree of undeveloped characteristics as measured by the level of human modification would 

be adversely impacted.

• Outstanding opportunities for solitude as measured by the opportunity to experience isolation from 

the evidence of humans would be adversely affected.

Additions to the NFTS: No direct or indirect effects would occur in IRAs because no unauthorized 

routes would be added to the NFTS under Alternative 1.

Establishment of Motorized “Open Areas”: No direct or indirect effects would occur in IRAs 

because no motorized “Open Areas” would be established under Alternative 1.

Changes to the NFTS: No direct or indirect effects would occur in IRAs because no changes would 

be made to the NFTS or to the existing closures under Alternative 1.

Amendments to the Forest Plan: No direct or indirect effects would occur in IRAs because there 

would be no Amendment to the Forest Plan under Alternative 1

Cumulative Effects

This alternative would contribute towards negative cumulative effects in IRAs because additional future 

route proliferation would adversely affect the roadless and wilderness characteristics within those areas.

Action Alternatives - Proposed Management Actions

Direct and Indirect Effects

The following section describes how proposed motor vehicle route additions and changes to the NFTS 

identified in the action alternatives could affect roadless and wilderness character within IRAs. Generally, 

motor vehicle use has an adverse effect on overall roadless and wilderness character. Conversely, 

reducing the amount of motorized use within an IRA would have a positive effect on roadless and 

wilderness characteristics. All routes under consideration for motorized use in IRAs are currently 

available to motorized use. The effect of this motorized use is already part of the existing situation.

Prohibiting motorized use on these routes would improve overall roadless and wilderness character within
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

Tahoe National Forest – 747

IRAs. Each action alternative analyzed in this FEIS would improve roadless and wilderness character of 

IRAs by reducing the amount of roads and trails available for motor vehicle use.

The statements listed below summarize the overall effects each action alternative would have on the 

roadless and wilderness character of IRAs located on Tahoe National Forest.

Cross Country Travel: Cross country travel would be prohibited on a total of 171,328 IRA acres 

(98,309 acres of proposed prohibition) in all the action alternatives. This prohibition would serve to stop

proliferation of unauthorized routes and would prohibit use on all unauthorized routes not proposed for 

addition as motor vehicle routes to the NFTS. It would also prohibit use on all closed NFTS roads not 

being re-opened that are currently receiving some motorized use. The mileage of routes open for motor 

vehicle use (NFTS and unauthorized) would be reduced considerably from the existing situation. 

Alternatives 3 and 4 would add zero miles of unauthorized routes, while Alternatives 2, 5, 6 and 7 would 

prohibit use on 36.9 (79%) to 43.1 (92%) miles of available unauthorized routes. Roadless and wilderness

characteristics would improve over time as unauthorized routes passively restore to natural conditions.

Additions to the NFTS: Within IRAs, there are only a few road segments being proposed for 

addition to the NFTS in the alternatives to provide access to dispersed recreation sites from existing 

NFTS roads. Four action alternatives would increase the mileage of NFTS motorized trails within 

affected IRAs. The majority of routes proposed for addition are existing short spurs accessing dispersed 

recreation sites adjacent to existing NFTS routes. The impact these additions would have on roadless and 

wilderness characteristics are explained in the effects analysis for each IRA.

Establish Motorized “Open Areas”: No motor vehicle “Open Areas” are being proposed for 

establishment within IRAs in any of the action alternatives; therefore, there is no effect on the IRAs and 

this will not be addressed under each IRA.

Changes to the NFTS: Alternatives 2, 5 and 6 would change the class of vehicles allowed on short 

sections of a few NFTS roads in IRAs from highway legal vehicles only to open to all vehicles. Those 

changes would be implemented through a combination of motorized mixed use and changes in vehicle 

class allowed. These proposed changes would not impact roadless and wilderness characteristics of the 

IRAs.

Alternatives 4, 5 and 6 would impose wet weather seasonal restrictions on all native surface roads and 

motorized trails. Seasonal restrictions would improve the following roadless and wilderness

characteristics: 1) High quality and undisturbed soil, water, and air resources; 2) Quality of water 

resources in the upper watersheds that become sources of public drinking water; 3) Opportunities for 

semi-primitive non-motorized and primitive recreation opportunities during the closure period; and 4)

Outstanding opportunities for solitude.

Reopening of Maintenance Level 1 (ML 1) roads will not be addressed in the individual IRAs since 

there are no ML 1 roads being opened in any IRA except the West Yuba IRA, where it will be addressed 

in more detail. Alternative 5 is the only alternative that would reopen a ML 1 road within an IRA 

Amendments to Forest Plan: Not applicable to the individual IRAs; therefore, this will not be 

addressed under each IRA.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

748 – Tahoe National Forest

Cumulative Effects

Each of the action alternatives would improve the roadless characteristics of IRAs by allowing 

motorized use on fewer miles of roads and trails and by prohibiting cross country travel. There are 

currently 206.9 miles (NFTS and unauthorized routes) available for public motorized use in the No Action 

Alternative. The action alternatives would all reduce the total number of miles available to public 

motorized use. The action alternatives range from 160.3 miles (23% reduction) of routes open for 

motorized use in Alternative 5, to 149.0 miles (28 % reduction) in Alternatives 3 and 4. The reduction of 

available roads and eventual natural restoration routes prohibited to use would slowly improve overall 

roadless characteristics over time.

Table 3.09-13 compares total differences between action alternatives within Inventoried Roadless 

Areas on Tahoe NF.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

Tahoe National Forest – 749

Table 3.09-13. Total Roads/Trails/Areas in Inventoried Roadless Areas by Alternative

Action type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

1. Cross-country travel (Acres) Prohibited on 

73,019 acres

Continues on 

98,309 acres

Prohibited 

on all 

171,328 

acres

Prohibited 

on all 

171,328 

acres

Prohibited 

on all 

171,328 

acres

Prohibited 

on all 

171,328 

acres

Prohibited 

on all 

171,328 

acres

Prohibited 

on all 

171,328 

acres

Unauthorized routes 46.7 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles

Closed NFTS roads receiving some motorized 

use

11.3 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles

2. Additions 

to the NFTS

a. Roads added to the NFTS 0.0 miles 0.1 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles

b. Motorized Trails added to the 

NFTS

0.0 miles 7.6 miles 0.0 miles 0.0 miles 9.8 miles 3.6 miles 6.2 miles

3. Establishment of Motorized “Open Areas” None None None None None None None

4. Changes 

to the NFTS

a. Change in Class of Vehicles 

resulting from approval of mixed 

use

0.0 miles 0.2 miles 0.0 miles 0.0 miles 0.2 miles 0.6 miles 0.0 miles

b. Change in Class of Vehicles 

resulting from changes in 

maintenance levels

0.0 miles 0.5 miles 0.0 miles 0.0 miles 0.5 miles 0.1 miles 0.0 miles

c. Change in Season of Use 0.0 miles 0.0 miles 0.0 miles 113.0 mi. 113.5 mi. 113.0 mi. 0.0 miles

d. Reopening Maintenance Level 

1 Roads

0.0 miles 0.0 miles 0.0 miles 0.0 miles 1.6 mi. 0.0 miles 0.0 miles

5. Amendments to the Forest Plan None None None None None None None

Total Mileage Open to Motorized Use 206.9 mi. 156.6 mi. 149.0 mi. 149.0 mi. 160.3 mi. 152.6 mi. 155.2 mi.

Percentage of Existing Routes Open for

Motor Vehicle Use

100% 76% 72% 72% 77% 74% 75%
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

750 – Tahoe National Forest

Bald Mountain IRA

Cross Country Travel: Cross country travel by motor vehicles within the Bald Mountain IRA would be 

prohibited on an additional 4,490 acres (5,834 total acres) in each action alternative. This prohibition 

would stop the proliferation of new unauthorized routes within the IRA. The prohibition of motorized 

cross country travel on existing unauthorized routes and NFTS routes that are still receiving some 

motorized use would reduce the total mileage of roads and trails available for motorized use. Each action 

alternative would reduce the amount of roads and trails available for motorized use from 10.2 miles to 5.3

miles. The prohibition of cross country travel would benefit the roadless area and wilderness 

characteristics of Bald Mountain IRA by stopping the proliferation of unauthorized routes and reducing 

the amount of roads and trails available for motorized use. Opportunities for semi-primitive motorized 

recreation opportunities would be reduced in all action alternatives.

Additions to the NFTS: There would be no roads or trails added to the NFTS within the Bald 

Mountain IRA in Alternatives 2, 3, 4, 5 or 7. Alternative 6 would add two very short spur trails (D_560-

20a, D_560-20b) accessing dispersed recreation sites. These NFTS trail additions total 114 feet in length. 

The addition of these trails to the NFTS would have little effect on the naturalness of the immediate area 

or the overall roadless characteristics due to their short length and pre-existence. Overall roadless 

characteristics would improve under all action alternatives as motor vehicle use would be prohibited on 

3.6 miles of unauthorized routes and 1.2 miles of closed NFTS roads still receiving motorized use.

Changes to the Existing NFTS: There are no changes proposed for the class of vehicles allowed on 

existing NFTS roads in any of the action alternatives. Alternatives 4, 5 and 6 would impose wet weather 

seasonal restrictions on all NFTS routes in the IRA. These seasonal restrictions would serve to improve

the following roadless area and wilderness characteristics: 1) High quality and undisturbed soil, water, 

and air resources; 2) Quality of water resources in the watershed that are sources of public drinking water;

3) Opportunities for semi-primitive non-motorized and primitive recreation opportunities during the 

closure period; and 4) Outstanding opportunities for solitude. Seasonal vehicle closures would negatively 

affect Semi-Primitive Motorized opportunities because motor vehicle access would be limited to open 

periods. 

Cumulative Effects: All of the action alternatives would improve the roadless characteristics within

Bald Mountain IRA by prohibiting motorized cross country travel on all 5,834 acres and reducing the 

amount of motorized access on the existing network of motorized routes. All of the action alternative 

would reduce the miles available for motorized use from 10.2 miles to 5.3 miles. Overall, roadless area 

characteristics would improve over time as unauthorized routes passively restore to natural conditions.

Castle Peak IRA

Cross Country Travel: Cross country travel by motor vehicles within the Castle Peak IRA would be 

prohibited on 15,738 acres in each action alternative. The prohibition of motorized cross country travel on 

existing unauthorized routes and NFTS routes that are still receiving some motorized use would reduce 

the total mileage of roads and trails available for motorized use. Alternatives 3 and 4 reduce the amount of 

roads and trails available for motorized use from 18.7 to 8.6 miles. Alternatives 2, 5, 6 and 7 reduce the 

amount of motorized roads and trails from 18.7 to 9.6 miles. The prohibition of cross country travel 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

Tahoe National Forest – 751

would benefit roadless area and wilderness characteristics of Castle Peak IRA by stopping the 

proliferation of unauthorized routes and reducing the amount of roads and trails available for motorized 

use. The prohibition of motorized travel on all unauthorized routes would have a negative effect on 

opportunities for dispersed motorized recreation.

Additions to the NFTS: There are no roads proposed for addition to the NFTS in any of the action 

alternatives within the Castle Peak IRA. Alternatives 3 and 4 would not designate any new routes for the 

NFTS. Alternatives 2, 5, 6 and 7 would add three motorized trails (TKN-J4, TKN-J5 and TKN-J6) to the 

NFTS totaling approximately one mile within the boundary of the IRA.

TKN-J5 (0.3 mi.) is a trail located in Castle Valley that terminates at “Slab Rock.” TKN-J4 is located 

west of Andesite Peak with approximately 0.6 miles located in the IRA. The third trail, TKN-J6 enters the 

eastern side of the IRA for approximately 0.1 miles, and provides access to the eastside of Summit Lake. 

Each of these routes access existing dispersed recreation sites. All of three trails enter the edges of Castle 

Peak IRA, and are close enough to Interstate 80 that traffic noise from the freeway is still noticeable. If 

designated, these routes would have a minor impact on solitude because the noise of motorized vehicles 

would not be louder than the background noise from the freeway in the immediate vicinity. Additionally, 

in Alternative 6, two short spur trails (D_14E08, D_TKN-004) totaling .02 mile in length would be 

designated to provide motor vehicle access to dispersed recreation sites.

By designating those preexisting routes, there would continue to be minor effects to the high scenic 

quality landscape of the IRA due to vegetative disturbance and compaction at turnaround points. The 

majority of the Castle Peak IRA would remain a good candidate as a reference landscape because 

proposed changes to the NFTS are on the periphery of the IRA. 

Changes to the NFTS: There are no changes to the class of vehicles allowed on existing National 

Forest System roads in any of the alternatives. However, Alternatives 4, 5 and 6 would impose wet 

weather seasonal restrictions on all native surface roads and motorized trails. These seasonal restrictions 

would improve roadless and wilderness characteristics values for: 1) High quality and undisturbed soil, 

water, and air resources; 2) Quality of water resources in the upper watersheds that become sources of 

public drinking water; 3) Opportunities for semi-primitive non-motorized and primitive recreation 

opportunities during the closure period; and 4) Outstanding opportunities for solitude. The seasonal 

closure of NFTS routes would have negative effects on opportunities for semi-primitive motorized 

experiences.

Cumulative Effects: All of the action alternatives would improve the overall roadless character of the 

Castle Peak IRA by prohibiting cross country motorized travel on 15,738 acres and thereby reducing the 

mileage of routes available for motorized use by approximately 60 percent. Alternatives 2, 5, 6, and 7 

reduce the miles open for motorized vehicles from 18.7 to 9.6. Alternatives 3 and 4 would prohibit use on 

all of the trails unauthorized for motorized use in this IRA. Overall, roadless area characteristics would 

improve over time as unauthorized routes passively restore to natural conditions.

Duncan Canyon IRA

Cross Country Travel: Each action alternative would prohibit cross country travel by motor vehicles on 

all 9,253 acres within the Duncan Canyon IRA. Prohibition of cross country travel, in each of the action 
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752 – Tahoe National Forest

alternatives, would reduce the total amount of roads and trails available for motorized use from 20.9 to 

12.0 miles. The prohibition of cross country travel would benefit the roadless area and wilderness

characteristics of this IRA by stopping the proliferation of unauthorized routes and reducing the amount 

of roads and trails available for motorized use.

Additions to the NFTS: There would be no additional roads designated within the Duncan Canyon 

IRA in any of the action alternatives. Alternatives 2, 4 and 5 would add one short motorized trail segment

(D_88) to the NFTS, and Alternative 6 would add two motorized trails (D_88, D16E10). Those trails

would be added to provide access to dispersed recreation sites. The addition of a few hundred feet of 

routes to the NFTS would have little effect on the overall roadless characteristics of the IRA due to their 

short length and pre-existence.

Changes to the NFTS: There are no changes to the class of vehicles allowed on existing NFTS

roads in the Duncan Canyon IRA in any of the alternatives. Alternatives 4, 5 and 6 would impose wet 

weather seasonal restrictions on all native surface roads and motorized trails (11.3 miles). Those seasonal 

restrictions would improve the following roadless areas characteristics: 1) High quality and undisturbed 

soil, water, and air resources; 2) Quality of water resources in the upper watersheds that all become 

sources of public drinking water; 3) Opportunities for semi-primitive non-motorized and primitive 

recreation opportunities during the seasonal closure period and 4) Outstanding opportunities for solitude.

The seasonal closure of NFTS routes would have negative effects on opportunities for semi-primitive 

motorized experiences.

Cumulative Effects: All of the action alternatives would improve the roadless character of the 

Duncan Canyon IRA by prohibiting cross country motorized travel on 9,253 acres and thereby reducing 

the mileage of routes available for motorized use by approximately 40 percent. Each action alternative 

would reduce the number miles open for motorized vehicles from 20.9 to 12.0 miles. Alternatives 3 and 4 

would eliminate use on all of the trails unauthorized for motorized use in this IRA. Overall, roadless area 

characteristics would improve over time as unauthorized routes passively restore to natural conditions.

East Yuba IRA

Cross Country Travel: Cross country travel by motor vehicles would be prohibited on 10,805 acres in 

each action alternative within the East Yuba IRA. This prohibition would also reduce the total amount of 

roads and trails available for motorized use. Alternatives 3 and 4 would reduce the amount of roads and 

trails available for motorized use from 42.9 to 33.5 miles. Alternatives 2, 5, 6 and 7 would reduce the 

amount of motorized roads and trails from 41.8 to 35.4, 36.8, 35.0 and 34.6 miles respectively. The 

prohibition of cross country travel would benefit the overall roadless area and wilderness characteristics 

of the IRA by stopping the proliferation of unauthorized routes and reducing the amount of roads and 

trails available for motorized use. The prohibition of cross country travel would eliminate use of all 

unauthorized routes in this IRA and would have a negative effect on opportunities for dispersed motorized 

recreation.

Additions to the NFTS: Alternatives 3 and 4 would not make any additions to the NFTS within the 

East Yuba IRA. Alternative 2 would add 18 motorized trails (1.8 miles) and one road (124 feet) to the 

NFTS. Alternative 5 would add 20 motorized trails (3.3 miles) to the NFTS. Alternative 6 would add 18 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

Tahoe National Forest – 753

motorized trails (1.5 miles) to the NFTS. Alternative 7 would add 4 motorized trails (1.1 miles) to the 

NFTS. Alternatives 5, 6, and 7 would not add any roads to the NFTS. Out of the 20 motorized routes, six 

of the longer routes are discussed below.

Route YRN-11 would be added as a motorized trail open to high clearance trail vehicles in 

Alternatives 2, 5, 6 and 7. This trail provides access to a dispersed recreation site near Spencer Lake. This 

trail would have a slight effect on roadless character within the IRA because it is a short segment (0.2 mi.) 

that closely parallels an existing NFTS route. 

Routes YRN-5a and YRN-5c would be added as motorized trails open to high clearance trail vehicles 

in Alternatives 2, 5, 6 and 7. These routes provide access to a remote, well-defined dispersed recreation

site off the Gold Valley four-wheel drive trail. Vehicle access tends to be by motorcycles and jeeps used 

by anglers, jeepers, and hunters. Eliminating motor vehicle access to this dispersed site would force 

individuals to utilize less desirable locations along the trail in the event they want to camp. The addition 

of these routes to the NFTS would have slight effects on roadless character because they are relatively 

short segments which access dispersed recreation sites. 

Route YRN-4 would be added as a motorized trail open to high clearance trail vehicles in Alternatives 

2, 5, 6 and 7. This trail, which is accessed from the Big Boulder four-wheel drive trail, is a historic mining 

route. The trail provides access to a scenic vista and has historically received heavy motorcycle use. 

Addition of this route would have a slight effect on roadless character because it is a short segment that 

stays relatively close to an existing NFTS route.

Route YRN-007 would be added as a motorized trail open to high clearance trail vehicles in 

Alternatives 2 and 5. This trail provides access to an old mine used for dispersed recreation. Only a short 

segment of YRN-007 enters the IRA along its eastern boundary. Since only the very end of the route is 

located within the IRA boundary there would be minimal effects to roadless area characteristics.

Route YRN-9 would be added as a motorized trail open to high clearance trail vehicles in Alternatives 

2 and 5. This trail is very faint on the ground. This trail is longer and affects the roadless character more 

because it is in the heart of the IRA and ventures farther from existing motorized system routes. It reduces 

the opportunities for solitude in a band along the trail because of the noise from the motorized vehicles. It 

would also retain a band of semi-primitive motorized character in that part of the IRA. 

Alternatives 2, 5 and 6 would add 14 trail segments that provide motor vehicle access to dispersed 

recreation sites within the IRA. The other action alternatives would have a negative impact on 

opportunities for semi-primitive motorized recreation by prohibiting motor vehicle access to identified 

dispersed recreation sites.

Changes to the NFTS: There are no changes in the class of vehicles allowed on existing NFS roads 

in any of the alternatives. Alternatives 4, 5 and 6 would impose wet weather seasonal restrictions on all 

native surface roads and motorized trails. These seasonal restrictions would improve the following 

roadless areas and wilderness characteristics: 1) High quality and undisturbed soil, water, and air 

resources; 2) Quality of water resources in the upper watersheds that are sources of public drinking water; 

3) Opportunities for semi-primitive non-motorized and primitive types of recreation; and 4) Outstanding 

opportunities for solitude during the closure period. Seasonal closures would have a negative effect on 

opportunities for semi-primitive motor vehicle experiences.
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Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

754 – Tahoe National Forest

Cumulative Effects: All of the action alternatives would improve the overall roadless character of the 

East Yuba IRA by prohibiting cross country motorized travel on 10,805 acres and reducing the number of 

trails with motorized use. The addition of motorized trails to the NFTS would continue to have minimal 

effects on roadless character because they are short segments of motorized trails that stay relatively close 

to an existing NFTS route. None of the motorized trails added to the NFTS in Alternative 2, 5, 6 and 7 

would have substantial effects, but in a cumulative fashion they would contribute to a reduction in 

roadless character in the IRA. Alternatives 3 and 4 would provide for the greatest improvement in overall 

roadless character because no motorized trails are proposed to be added to the NFTS in those alternatives.

Overall, roadless area characteristics within this IRA would improve over time as unauthorized routes 

passively restore to natural conditions

Table 3.09-14 displays the acres available for cross country travel and miles of roads and trails 

available for motorized use in the East Yuba IRA for the range of action alternatives.
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Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

Tahoe National Forest – 755

Table 3.09-14. Miles of Roads/Trails/Areas in East Yuba Inventoried Roadless Area by Alternative

Action type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

1. Cross-country travel (Acres) Prohibited on 612

acres

Continues on 

10,193 acres

Prohibited 

on all 

10,805

acres

Prohibited 

on all 

10,805

acres

Prohibited 

on all 

10,805

acres

Prohibited 

on all 

10,805

acres

Prohibited 

on all 

10,805

acres

Prohibited 

on all 

10,805

acres

Miles of unauthorized routes open to motor 

vehicle use

9.4 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles

2. Additions 

to the NFTS

a. Roads added to the NFTS 0.0 miles 124 feet 0.0 miles 0.0 miles 0.0 miles 0.0 miles. 0.0 miles

b. Motorized Trails added to 

the NFTS

0.0 miles 1.8 miles 0.0 miles 0.0 miles 3.3 miles 1.5 miles 1.1 miles

3. Establishment of Motorized “Open Areas” None None None None None None None

4. Changes 

to the NFTS

a. Change in Class of Vehicles 

resulting from approval of mixed 

use

0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.01 mi. 0.01 mi. 0.0 miles

b. Change in Class of Vehicles 

resulting from changes in 

maintenance levels

0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles

c. Change in Season of Use 0.0 miles 0.0 miles 0.0 miles 29.0 mi. 29.0 mi. 29.0 mi. 0.0 miles

d. Reopening Maintenance Level 

1 Roads

0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles

5. Amendments to the Forest Plan None None None None None None None

Total Miles Open to Motorized Use* 42.8 miles 35.3 mi. 33.5 mi. 33.5 mi. 36.8 mi. 35.0 mi. 34.6 mi.

*Includes State, County and private jurisdiction roads in all alternatives. Alternative 1 includes unauthorized routes and closed NFTS roads still receiving motorized use.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

756 – Tahoe National Forest

Granite Chief IRA

Cross Country Travel: Cross country travel would be prohibited on the entire 31,297 acres of the 

Granite Chief IRA in all action alternatives. Most of this acreage is within Wilderness or management 

areas that already preclude the use of motor vehicles. The remaining 1,930 acres of this IRA would be

prohibited for cross country travel in the action alternatives. On NFS land, only 0.3 miles of unauthorized 

routes exist within the IRA. These routes would no longer be available for motorized use in the action 

alternatives. The prohibition of cross country travel would benefit the roadless and wilderness 

characteristics of the Granite Chief IRA by preventing the proliferation of unauthorized routes and by 

eliminating motorized use on the only existing motor vehicle route in the IRA.

Additions to the NFTS: There are no roads or trails proposed for addition to the NFTS in any of the 

action alternatives. 

Changes to the NFTS: There are no proposed changes in class of vehicle or season of use on NFTS 

roads or trails in any of the action alternatives.

Cumulative Effects: Each action alternative would improve the roadless and wilderness character of 

the Granite Chief IRA. The heart of Granite Chief IRA is a congressionally designated wilderness that 

precludes motorized use. The only possible negative impacts to roadless characteristics would be if cross 

country travel were allowed in parts of the IRA that are not wilderness or that currently prohibit motor 

vehicle use.

Grouse Lakes IRA

Cross Country Travel: Cross country travel would be prohibited on all 19,271 acres of this IRA in each

of the action alternatives. The prohibition of cross country would reduce the total amount of roads and 

trails available for motorized use. Alternatives 3 and 4 reduce the amount of roads and trails available for 

motorized use from 20.5 to 17.1 miles. Alternatives 2 and 5 reduce the amount of motorized roads and 

trails from 20.5 to 18.3 miles. Alternatives 6 and 7 reduce the amount of motorized roads and trails from 

20.5 to 18.1 miles. The prohibition of cross country travel would benefit roadless and wilderness 

characteristics within Grouse Lakes IRA by stopping the proliferation of unauthorized routes and 

reducing the amount of roads and trails available for motorized use. The prohibition of motorized cross 

country travel in this IRA would have a positive effect on opportunities for dispersed non-motorized 

recreation.

Additions to the NFTS: Alternatives 3 and 4 would not make any additions to the NFTS. Alternative 

2 would add 4 motorized trails (1.2 miles) and 2 roads (199 feet) to the NFTS. Alternative 5 would add 6 

motorized trails (1.2 miles) to the NFTS. Alternative 6 would add 6 motorized trails (1.0 miles) to the 

NFTS. Alternative 7 would add 3 motorized trails (1.1 miles) to the NFTS. Refer to Table 3.09-15. Two of 

the longer routes that are in Alternatives 2, 5, 6, and 7 are discussed below.

Trail YRS-F1 consists of several short spurs accessing dispersed recreation sites along the Fordyce 

Jeep Trail within Grouse Lakes IRA. The effects to roadless character would be limited due to the short 

length of the routes and their close proximity to the existing motorized trail. The routes do extend the 

motorized influence into a wider band along the Fordyce Jeep trail. This would result in slightly more 
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Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

Tahoe National Forest – 757

impact on opportunities for solitude and other experiences related to semi-primitive non-motorized 

recreation.

Another motorized trail (YRS-G3), approximately one-mile in length would also be added to the 

NFTS north and east of Baltimore Lake, in Alternatives 2, 5, 6, and 7. Adding this motorized trail would 

have negative effects to roadless character because it is separate from, and beyond, the Fordyce Jeep 

Trail. Adding this route to the NFTS would affect opportunities for solitude because of noise from motor 

vehicle use. Likewise there is a band of influence along the motorized trail where the ROS opportunities 

would be semi-primitive motorized rather than semi-primitive non-motorized. The natural appearing 

landscape and high scenic quality is only slightly affected due to the continuing existence of the 

motorized trail. 

Changes to the NFTS: There would be no changes to the class of vehicles allowed on all existing 

NFTS routes in any of the action alternatives. Alternatives 4, 5 and 6 would impose wet weather seasonal 

restrictions on all native surface roads and motorized trails. These seasonal restrictions would improve the 

following roadless area characteristics: 1) High quality and undisturbed soil, water, and air resources; 2) 

Quality of water resources in the upper watersheds that are sources of public drinking water; 3) 

Opportunities for semi-primitive non-motorized and primitive recreation opportunities and 4) Outstanding 

opportunities during the closure period. Seasonal restrictions would negatively affect opportunities for 

semi-primitive motorized experiences.

Cumulative Effects: Each of the action alternatives would improve roadless characteristics within 

Grouse Lakes IRA through the prohibition of cross country travel across 19,271 acres and reducing the 

mileage of roads and trails available for motorized use. Overall, roadless area characteristics within this 

IRA would improve over time as unauthorized routes passively restore to natural conditions.
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758 – Tahoe National Forest

Table 3.09-15. Miles of Roads/Trails/Areas in Grouse lakes Inventoried Roadless Area by Alternative

Action type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

1. Cross-country travel (Acres) Prohibited on 

13,190 acres

Continues on 

6,081 acres

Prohibited 

on all 

19,271 

acres

Prohibited 

on all 

19,271 

acres

Prohibited 

on all 

19,271 

acres

Prohibited 

on all 

19,271 

acres

Prohibited 

on all 

19,271 

acres

Prohibited 

on all 

19,271 

acres

Miles of unauthorized routes open to motor 

vehicle use

3.3 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles

Closed NFTS roads still receiving some 

motorized use

.2 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles

2. Additions 

to the NFTS

a. Roads added to the NFTS 0.0 miles 199 feet 0.0 miles 0.0 mile 0.0 mile 0.0 miles. 0.0 miles

b. Motorized Trails added to the 

NFTS

0.0 miles 1.2 miles 0.0 miles 0.0 miles 1.2 miles 1.0 miles. 1.1 miles

3. Establishment of Motorized “Open Areas” None None None None None None None

4. Changes 

to the NFTS

a. Change in Class of Vehicles 

resulting from approval of mixed 

use

0.0 miles 0.01 mi. 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles

b. Change in Class of Vehicles 

resulting from changes in 

maintenance levels

0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles

c. Change in Season of Use 0.0 miles 0.0 miles 0.0 miles 14.4 mi. 14.4 mi. 14.4 mi. 0.0 miles

d. Reopening Maintenance Level 

1 Roads 

0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles

5. Amendments to the Forest Plan None None None None None None None

Total Miles Open to Motorized use* 20.5 miles 18.3 mi. 17.1 mi. 17.1 mi. 18.3 mi. 18.1 mi. 18.1 mi.

*Includes State, County and private jurisdiction roads in all alternatives. Alternative 1 includes unauthorized routes and closed NFTS roads still receiving motorized use.
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Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

Tahoe National Forest – 759

Lakes Basin IRA

Cross Country Travel: Each action alternative would prohibit cross country travel by motor vehicles on 

557 acres within the Lakes Basin IRA. The prohibition of cross country travel would benefit roadless area 

and wilderness characteristics of the Lakes Basin IRA by stopping the proliferation of unauthorized routes 

and reducing the amount of roads and trails available for motorized use. The prohibition of motorized 

travel on all unauthorized routes would have a negative effect on opportunities for dispersed motorized 

recreation.

Additions to the NFTS: There are no roads or motorized trails proposed for addition to the NFTS in 

any of the action alternatives in this IRA.

Changes to the NFTS: There are no proposed vehicle class changes on NFTS roads in any of the 

action alternatives. Alternatives 4, 5 and 6 would impose wet weather seasonal restrictions on all native 

surface roads and motorized trails. These seasonal restrictions would improve the following roadless area 

characteristics: 1) High quality and undisturbed soil, water, and air resources; 2) Quality of water 

resources in the upper watersheds that are sources of public drinking water; 3) Opportunities for semiprimitive non-motorized and primitive recreation opportunities and 4) Outstanding opportunities for 

solitude during the seasonal closure period.

Cumulative Effects: All action alternatives would serve to improve the roadless characteristics of the 

Lakes Basin IRA by prohibiting cross country travel on 557 acres and reducing the amount of roads and 

trails available for motorized use. No unauthorized routes are proposed for addition to the NFTS within 

this IRA in any of the action alternatives. Overall, roadless area characteristics within the Lakes Basin

IRA would improve over time as unauthorized routes passively restore to natural conditions.

Middle Yuba IRA

Cross Country Travel: Cross country travel would be prohibited on all 7,884 acres of this IRA in each of 

the action alternatives. The prohibition of cross country motor vehicle travel would reduce the total 

amount of roads and trails available for motorized use from 29.4 to 23.4 miles for each alternative. The 

prohibition of cross country travel would benefit overall roadless area and wilderness characteristics of 

the Middle Yuba IRA by stopping the proliferation of unauthorized routes and reducing the amount of 

roads and trails available for motorized use. The prohibition of motorized use on all unauthorized routes 

in this IRA would have a negative effect on opportunities for semi-primitive motorized recreation. 

Additions to the NFTS: There are no roads or motorized trails being proposed for addition to the 

NFTS in any of the action alternatives for this IRA.

Changes to the NFTS: Alternatives 2, 5 and 6 would change the class of vehicles allowed on all

NFTS roads within this IRA from highway legal vehicles only to open to all vehicles (total .6 mi.).The 

change in vehicle class allowed would not have an effect on roadless area characteristics of this IRA.

Alternatives 4, 5 and 6 would impose wet weather seasonal restrictions on all native surface roads and 

motorized trails. These seasonal restrictions would improve the roadless areas characteristics for: 1) High 

quality and undisturbed soil, water, and air resources; 2) Quality of water resources in the upper 

watersheds that are sources of public drinking water; 3) Opportunities for semi-primitive non-motorized 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

760 – Tahoe National Forest

and primitive recreation opportunities and 4) Outstanding opportunities for solitude during the closure 

period.

Cumulative Effects: Each of the action alternatives would improve the roadless character of the 

Middle Yuba IRA by prohibiting cross country travel and reducing the amount of roads and trails 

available for motorized use within the IRA. No motorized trails would be added to the NFTS within this

IRA. Overall, roadless area characteristics within this IRA would improve over time as unauthorized 

routes passively restore to natural conditions.

North Fork American River IRA

Cross Country Travel: Each action alternative would prohibit cross country travel on 43,374 acres 

within the North Fork American River IRA. This prohibition would reduce the total amount of roads and 

trails available for motorized use from 9.0 to 6.6 miles in each action alternative. The prohibition of cross 

country travel would benefit overall roadless area and wilderness characteristics within the IRA by 

stopping the proliferation of unauthorized routes and reducing the amount of roads and trails available for 

motorized use. The prohibition of motorized use of all unauthorized routes in this IRA would have a 

negative effect on opportunities for dispersed motorized recreation.

Additions to the NFTS: There are no roads or motorized trails added to the NFTS in this IRA in any 

of the action alternatives. 

Changes to the NFTS: Alternatives 2, 5 and 6 would change the class of vehicles allowed on all

NFTS roads within the North Fork American River IRA from highway legal vehicles only to open to all 

vehicles (total .1 mi.).The change in vehicle class allowed would not have an effect on roadless area 

characteristics of this IRA. Alternatives 4, 5 and 6 would impose wet weather seasonal restrictions on all 

native surface roads and motorized trails. These seasonal restrictions would improve the roadless areas 

characteristics for: 1) High quality and undisturbed soil, water, and air resources; 2) Quality of water 

resources in the upper watersheds that are sources of public drinking water; 3) Opportunities for semiprimitive non-motorized and primitive recreation opportunities and 4) Outstanding opportunities for 

solitude during the closure period.

Cumulative Effects: Each of the action alternatives would improve the roadless character of the 

North Fork American River IRA by prohibiting cross country travel on 43,374 acres and reducing the 

amount of roads and trails available for motorized use. The IRA remains intact with high levels of 

primitive to semi-primitive non-motorized recreation opportunities that maintain the high quality roadless 

characteristics in each action alternative. Overall, roadless area characteristics within this IRA would 

improve over time as unauthorized routes passively restore to natural conditions.

North Fork of the Middle Fork of the American River IRA

Cross Country Travel: Each action alternative would prohibit cross country travel on 11,257 acres 

within the North Fork of the Middle Fork American River IRA. This prohibition would reduce the total 

amount of roads and trails available for motorized use from 18.2 to 16.9 miles in each action alternative.

The prohibition of cross country travel would benefit roadless area and wilderness characteristics within 

the IRA by stopping the proliferation of unauthorized routes and reducing the amount of roads and trails 
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Tahoe National Forest – 761

available for motorized use. The prohibition of motorized use on all unauthorized routes in this IRA 

would have a negative effect on opportunities for dispersed motorized recreation.

Additions to the NFTS: There are no roads or motorized trails proposed for addition to the NFTS in 

any of the action alternatives.

Changes to the NFTS: None of the action alternatives proposes changes to the vehicle class allowed 

on NFTS routes within the North Fork of the Middle Fork American River IRA. Alternatives 4, 5 and 6 

would impose wet weather seasonal restrictions on all NFTS routes. These seasonal restrictions would 

improve the following roadless area characteristics: 1) High quality and undisturbed soil, water, and air 

resources; 2) Quality of water resources in the upper watersheds that are sources of public drinking water;

3) Opportunities for semi-primitive non-motorized and primitive recreation opportunities; and 4) 

Outstanding opportunities for solitude during the closure period.

Cumulative Effects: Due to the very steep topography of the area, only 1.2 miles of unauthorized 

routes and .1 miles of closed NFTS roads are currently receiving some motor vehicle use. Those routes 

would be prohibited to motor vehicle use in each of the action alternatives. Overall, roadless area 

characteristics within the North Fork of the Middle Fork American River IRA would improve over time 

as unauthorized routes passively restore to natural conditions.

West Yuba IRA

Cross Country Travel: Each of the action alternatives would prohibit cross country travel by motor 

vehicles on the entire 16,058 acres within the West Yuba IRA. Alternatives 3 and 4 would reduce the 

amount of roads and trails available for motorized use from 35.7 to 24.4 miles. Alternatives 2, 5, 6 and 7 

would reduce the amount of motorized roads and trails from 35.7 to 28.0, 30.2, 24.5 and 27.4 miles 

respectively through the prohibition of motorized use on several miles of unauthorized routes. The 

prohibition of cross country travel would benefit overall roadless area and wilderness characteristics of 

this IRA by stopping the proliferation of unauthorized routes and reducing the amount of roads and trails 

available for motorized use. The prohibition of motorized use of all unauthorized routes in this IRA would 

have a negative effect on opportunities for dispersed motorized recreation.

Additions to the NFTS: Alternatives 3 and 4 would not make any additions to the NFTS. Alternative 

2 would add 5 motorized trails (3.6 miles) to the NFTS. Alternative 5 would add 6 motorized trails (4.2 

miles) to the NFTS. Alternative 6 would add 4 motorized trails (300 feet total) to the NFTS. Alternative 7 

would add 2 motorized trails (2.9 miles) to the NFTS. Refer to Table 3.09-16. Three of the longer routes 

that are in the action alternatives are discussed below.

Route YRN-M2 would be added to the NFTS as a motorized trail open to motorcycles in Alternatives 

2 and 5. Use of the motorized trail would be seasonally prohibited for wet weather in Alternative 5. This 

motorized trail connects the Downieville single track trail to a difficult four-wheel drive trail. This 

motorized trail creates a loop to Chimney Rock and Poker Flat. It provides very challenging double black 

diamond riding (limited opportunities), requiring slower travel (less noise). The motorized trail parallels 

the Downie River for a short distance and connects challenging four-wheel drive and motorcycle trails 

along the river. Opening this trail to motorcycle use would have a negative effect on solitude because of
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

762 – Tahoe National Forest

motorcycle noise. Due to the low numbers of users this effect would occur primarily on weekends. The 

motorized use of this trail is consistent with semi-primitive motorized standards in the Forest Plan. The 

addition of this existing trail to the NFTS would have a minor negative effect on the overall natural 

appearing landscape and high scenic quality of the area.

Route YRN-M3b would be added to the NFTS as a motorized motorcycle trail in Alternatives 2, 5 

and 7. Use of this motorized trail would be seasonally prohibited for wet weather in Alternatives 5 and 6. 

The route is an old historic mining trail that requires a high skill level to navigate. It provides loop 

connection from Downie River to the Castle Rock trails system. Opening this trail to motorcycle use 

would have a negative effect on solitude because of motorcycle noise. Due to the low numbers of users, 

this effect would occur primarily on weekends. The motorized use of this trail is consistent with semiprimitive motorized standards in the Forest Plan. The addition of this route would have an effect on the 

overall natural appearing landscape and high scenic quality of the area.

Route YRN-7 would be added to the NFTS as a motorized trail open to high clearance trail vehicles 

in Alternatives 2, 5 and 7. Use of this motorized trail would be seasonally prohibited for wet weather in 

Alternatives 5. This route is a short 1⁄4-mile spur located adjacent to two system routes: the Poker Flat and 

Texas Flat four-wheel drive routes. Poker Flat is a high value recreation destination associated with this 

motorized trail. This route continues to a popular vista point. Current use is low. This motorized trail is in 

the north east corner of the IRA. It has similar effects as described above with other proposed motorcycle 

trails with there being a slightly higher impact because the width of the trail is greater.

Changes to the NFTS: There are no changes to the class of vehicles allowed on existing NFTS roads 

in any of the alternatives. Alternatives 4, 5 and 6 would impose wet weather seasonal restrictions on all 

native surface roads and motorized trails. Seasonal restrictions would improve the following roadless area 

characteristics: 1) High quality and undisturbed soil, water, and air resources; 2) Quality of water 

resources in the upper watersheds that all become sources of public drinking water; 3) Opportunities for 

semi-primitive non-motorized and primitive recreation opportunities; and 4) Outstanding opportunities 

for solitude during the seasonal closure period. Opportunities for semi-primitive motorized activity would 

be reduced with implementation of seasonal restrictions. One Maintenance Level 1 road would re-opened 

in Alternative 5 totaling 1.6 miles. This route is located on the western edge of the West Yuba IRA west of 

Poker Flat in the Canyon Creek drainage. Opening this route to motorized use would have a negative 

effect on solitude because of noise. The re-opening of this existing route would have a minor negative 

effect on the overall natural appearing landscape and high scenic quality of the area.

Cumulative Effects: Each action alternative would improve the roadless character of the West Yuba 

IRA by prohibiting cross country travel on 16,058 acres and reducing the amount of roads and trails 

available for motorized use. If added to the NFTS, YRN-M3b and YRN-M2 would affect roadless 

characteristics, especially opportunities for recreation in a semi-primitive non-motorized setting. The 

main effect these motorized trails have is the negative effects on solitude from motorcycle noise. Due to 

the low numbers of users, this effect would occur primarily on weekends. The motorized use of these 

trails is consistent with semi-primitive motorized standards in the Forest Plan. These motorized trails 

affect the naturalness for a reference landscape in a very slight way. YRN 7 is a jeep route in the north 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

Tahoe National Forest – 763

east corner of West Yuba which would be added to the NFTS in Alternatives 2, 5 and 7. It has similar

effects as described above for the motorcycle trails with there being a slightly higher impact because the 

width of the trail is greater. Alternative 5 would result in the least improvement in roadless character 

because four motorized trails would be added to the NFTS and one ML 1 road would be reopened. While 

the effects to roadless character from adding these routes are not great, the cumulative effects are greater

particularly because the proposed motorized trails (not the ML 1 road) are within the heart of the IRA.

Alternatives 2 and 7 have greater benefits to roadless character than Alternative 5 because the designated 

system would have less mileage of motorized routes in the area. Alternatives 3 and 4 would not add 

motorized trails to the NFTS in the West Yuba IRA and would have the most positive effect for 

maintaining roadless characteristics in the area. Alternative 6 is similar to Alternatives 3 and 4, except that 

it would provide opportunities for motorized access to four dispersed recreation sites.
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Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

764 – Tahoe National Forest

Table 3.09-16. Miles of Roads/Trails/Areas in West Yuba Inventoried Roadless Area by Alternative

Action type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

1. Cross-country travel (Acres) Prohibited on zero 

acres

Continues on 

16,058 acres

Prohibited 

on all 

16,058 

acres

Prohibited 

on all 

16,058 

acres

Prohibited 

on all 

16,058 

acres

Prohibited 

on all 

16,058 

acres

Prohibited 

on all 

16,058 

acres

Prohibited 

on all 

16,058 

acres

Miles of unauthorized routes open to motor 

vehicle use

1.8 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles

Closed NFTS roads still receiving some 

motorized use

9.4 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles

2. Additions 

to the NFTS

a. Roads added to the NFTS 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles

b. Motorized Trails added to the 

NFTS

0.0 miles 3.6 miles 0.0 miles 0.0 miles 4.2 miles 300 feet 2.9 miles

3. Establishment of Motorized “Open Areas” None None None None None None None

4. Changes 

to the NFTS

a. Change in Class of Vehicles 

resulting from approval of mixed 

use

0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles

b. Change in Class of Vehicles 

resulting from changes in 

maintenance levels

0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles

c. Change in Season of Use 0.0 miles 0.0 miles 0.0 miles 23.9 mi. 29.7 mi. 24.0 mi. 0.0 miles

d. Reopening Maintenance Level 

1 Roads 

0.0 miles 0.0 miles 0.0 miles 0.0 miles 1.6 miles 0.0 miles 0.0 miles

5. Amendments to the Forest Plan None None None None None None None

Total Miles Open to Motorized use* 35.7 miles 28.0 mi. 24.4 mi. 24.4 mi. 30.2 mi. 24.5 mi. 27.4 mi.

*Includes State, County and private jurisdiction roads in all alternatives. Alternative 1 includes unauthorized routes and closed NFTS roads still receiving motorized use.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

Tahoe National Forest – 765

Citizen Inventoried Roadless Areas (CIRAs): Affected Environment

The California Wilderness Coalition (CWC) inventory identified approximately 113,474 acres of land on 

the Tahoe NF as potential wilderness (CIRAs). Approximately 83% of those acres are already located 

within agency-identified IRAs and are included in the IRA analysis. The additional 17,964 acres 

(excluding 1,185 acres of private inholdings) of CIRAs being analyzed include dispersed recreation sites, 

trailheads, and NFTS roads. Approximately 56% of this acreage is included within the Roaded Natural 

ROS Class, while 30% is identified as Primitive Motorized, and 14% as Primitive Non-motorized. Table 

3.09-17 shows the amount of roads and trails in the CIRA’s by category.

Large tracts of CIRA acreage outside agency-identified IRAs include approximately 4,400 acres in the 

Castle Peak vicinity (Castle Peak CIRA); 3,000 acres south of Granite Chief Wilderness (Granite Chief 

Additions CIRA); 4,500 acres in the Grouse Lakes (Grouse Lakes CIRA) vicinity; 1,100 acres adjacent to 

the North Fork American River IRA (N.F. American River CIRA); and 5,800 acres adjacent to North Fork 

of the Middle Fork of the American River IRA (Black Oak CIRA).

Table 3.09-17. Roads and Trails in Citizen Inventoried Roadless Areas (total TNF acreage outside IRAs)

Road and Trail Category Season of Use Miles

Cross Country Travel (acreage open to motorized use: 15,472)

Unauthorized routes 

Closed NFTS roads receiving some motorized use

Not Applicable 19.6

6.1 

NFTS Roads open to all vehicles All Year/Seasonal 12.2

NFTS Trails open to high clearance trail vehicles All Year 2.1

NFTS Trails open to motorcycles All Year 3.7

Roads/trails on private land Not Applicable 4.1

Total Motorized Open to Public 47.8

Citizen Inventoried Roadless Areas: Environmental Consequences

Alternative 1 (No Action)

Direct and Indirect Effects

Cross Country Travel: The No Action Alternative could reduce roadless and wilderness character in 

CIRAs because cross country travel by motor vehicles would be allowed to continue on 15,472 acres of 

CIRAs currently open to motorized use on Tahoe NF. Motor vehicle travel is already prohibited on 2,492

acres of lands being managed for semi-primitive non-motorized recreation use within the affected CIRAs. 

Under Alternative 1, 19.6 miles of unauthorized routes and 6.1 miles of closed NFTS roads would 

continue to have some motor vehicle use in CIRAs.

Increased noise generated by motor vehicles and more evidence of human activity due to crosscountry travel with continued route proliferation would alter the following roadless and wilderness 

characteristics:

• High quality or undisturbed soil, water and air would be degraded. 

• Sources of public drinking water would be at higher risk.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

766 – Tahoe National Forest

• Diversity of plant and animal communities would be diminished.

• Habitat for threatened, endangered, proposed, candidate and sensitive species and for those species 

dependent on large, undisturbed areas of land would be degraded.

• Primitive and Semi-Primitive Non-Motorized recreation opportunities would be adversely 

impacted. 

• Natural appearing landscapes with high scenic quality would be adversely impacted.

• Natural ecological systems would be adversely impacted.

• The degree of undeveloped characteristics as measured by the level of human modification would 

be adversely impacted.

• Outstanding opportunities for solitude as measured by the opportunity to experience isolation from 

the evidence of humans would be adversely affected.

Additions to the NFTS: No direct or indirect effects would occur in CIRAs because no unauthorized 

routes would be added to the NFTS under Alternative 1.

Establishment of Motorized “Open Areas”: No direct or indirect effects would occur in CIRAs 

because no motorized “Open Areas” would be established under Alternative 1.

Changes to the NFTS: No direct or indirect effects would occur in CIRAs because no changes would 

be made to the NFTS or to the existing closures under Alternative 1.

Amendments to the Forest Plan: No direct or indirect effects would occur in CIRAs because there 

would be no Amendment to the Forest Plan under Alternative 1.

Cumulative Effects

This alternative would contribute towards negative cumulative effects in CIRAs because additional future 

route proliferation would adversely affect roadless and wilderness characteristics within those areas.

Action Alternatives - Proposed Management Actions

Direct and Indirect Effects

The following section describes how proposed motor vehicle route additions and changes to the NFTS 

identified in the action alternatives could affect roadless and wilderness character within CIRAs. 

Generally, motor vehicle use has an adverse effect on overall roadless and wilderness character. 

Conversely, reducing the amount of motorized use within a CIRA would have a positive effect on roadless 

and wilderness characteristics. All routes under consideration for motorized use in CIRAs are currently 

available to motorized use. The effect of this motorized use is already part of the existing situation. 

Prohibiting motorized use on these routes would improve overall roadless and wilderness character within 

CIRAs. Each action alternative analyzed in this FEIS would improve roadless and wilderness character of 

CIRAs by reducing the amount of roads and trails available for motor vehicle use. 

The statements listed below summarize the overall effects each action alternative would have on the 

roadless and wilderness character of CIRAs located on Tahoe National Forest. 

Cross Country Travel: Each of the action alternatives would prohibit cross country travel by motor 

vehicles on the entire 17,964 acres within CIRAs resulting in several miles of unauthorized routes. 
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Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

Tahoe National Forest – 767

Alternatives 3, 4, and 7 would reduce the amount of roads and trails available for motorized use from 47.8

to 22.1 miles. Alternatives 2, 5, and 6 would reduce the amount of motorized roads and trails from 47.8 to 

23.2, 23.4, and 23.9 miles respectively. The prohibition of cross country travel would benefit overall 

roadless area and wilderness characteristics of this CIRA by stopping the proliferation of unauthorized 

routes and reducing the amount of roads and trails available for motorized use. The prohibition of 

motorized use of all unauthorized routes in this CIRA would have a negative effect on opportunities for 

dispersed motorized recreation.

Additions to the NFTS: Alternative 3 would not make any additions to the NFTS. Alternative 2

would add two road segments (0.2 miles total) and two motorized trail segments (0.9 miles) to the NFTS. 

Alternative 4 would add one road segment (0.02 miles total) to the NFTS. Alternative 5 would add two 

road segments (0.2 miles total) and three motorized trail segments (0.9 miles total) to the NFTS. 

Alternative 6 would add six road segments (0.6 miles total) and three motorized trails (1.2 miles total) to 

the NFTS. Alternative 7 would add one trail segment (0.6 miles total) to the NFTS (Refer to Table 3.09-

18). Four of the routes proposed for addition in the action alternatives are discussed below.

Route YRS-003B (0.34 miles) would be added to the NFTS as a motorized trail open to high 

clearance vehicles in Alternatives 2, 5, and 6. Use of this route would be seasonally prohibited for wet 

weather in Alternatives 5 and 6. The motorized use of this trail is consistent with semi-primitive 

motorized standards in the Forest Plan. The addition of this existing trail to the NFTS would have a minor 

negative effect on the overall natural appearing landscape and high scenic quality of the area.

Route TKS-11 would be added to the NFTS as a motorized trail open to high clearance vehicles in 

Alternatives 2, 5, 6, and 7. The route accesses a well-developed dispersed recreation site located near the 

Rubicon River. Use of this motorized trail would be seasonally prohibited for wet weather in Alternatives 

5, 6, and 7. The motorized use of this trail is consistent with semi-primitive motorized standards in the 

Forest Plan. The addition of this route would have a minor effect on the overall natural appearing 

landscape and high scenic quality of the area.

Route ARM-90 (0.3 miles) would be added in Alternative 6 as a motorized trail in order to access an 

isolated NFTS motorized trail. No resource concerns have been noted for addition of this route which is 

located in a Roaded Natural ROS class

Route D_16TH19-1 (0.4 miles) would be added as an ML2 road in order to access a popular 

dispersed recreation site. No resource concerns were noted for addition of this route which is located in a 

Roaded Natural ROS class.

Establishment of Motorized “Open Areas”: Not applicable to these areas.

Changes to the NFTS: There is one proposed change to the class of vehicles allowed on existing 

NFTS Roads 3 and 3-4. A total of .35 mile of these roads within the Granite Chief Additions CIRA would 

be downgraded from an ML-3 road to an ML-2 to provide OHV users with a connection between road 

systems open to travel by non-highway legal vehicles. This change would have no affect on overall 

roadless characteristics.

Alternatives 4, 5 and 6 would impose wet weather seasonal restrictions on the majority of native 

surface NFTS roads and motorized trails. Seasonal restrictions would improve the following roadless area 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

768 – Tahoe National Forest

and wilderness characteristics: 1) High quality and undisturbed soil, water, and air resources; 2) Quality 

of water resources in the upper watersheds that all become sources of public drinking water; 3) 

Opportunities for semi-primitive non-motorized and primitive recreation opportunities; and 4) 

Outstanding opportunities for solitude during the seasonal closure period. Opportunities for semiprimitive motorized activity would be reduced with implementation of seasonal restrictions. 

Cumulative Effects

Each action alternative would improve the overall roadless character of the affected CIRAs by prohibiting 

cross country travel on 17,964 acres and reducing the amount of roads and trails available for motorized 

use.

Each of the action alternatives would reduce the mileage of routes available to motorized use by at 

least 50%. Alternative 4 would protect the most roadless and wilderness characteristics of the affected 

CIRAs because it would only add one short road segment (0.02 miles) to the NFTS and would implement 

seasonal use restrictions on 18.0 miles of existing NFTS roads and trails. Alternative 2 would protect the 

least overall roadless and wilderness characteristics as it would add 1.1 miles of motor vehicle routes to 

the NFTS and not implement any seasonal use restrictions on motor vehicle use.

Overall, each of the action alternatives would gradually improve roadless area and wilderness 

characteristics within the affected CIRA acreage over time as unauthorized routes passively restore to 

natural conditions.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

Tahoe National Forest – 769

Table 3.09-18. Total Roads/Trails/Areas in Citizen Inventoried Roadless Areas by Alternative

Action type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

1. Cross-country travel (Acres) Prohibited on 

2,492 acres

Continues on 

15,472 acres

Prohibited 

on all 

17,964 

acres

Prohibited 

on all 

17,964

acres

Prohibited 

on all 

17,964

acres

Prohibited 

on all 

17,964

acres

Prohibited 

on all 

17,964

acres

Prohibited 

on all 

17,964

acres

Unauthorized routes 19.6 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles

Closed NFTS roads receiving some motorized 

use

6.1 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles

2. Additions 

to the NFTS

a. Roads added to the NFTS 0.0 miles 0.2 miles 0.0 miles 0.02 miles 0.2 miles 0.6 miles 0.0 miles

b. Motorized Trails added to the 

NFTS

0.0 miles 0.9 miles 0.0 miles 0.0 miles 1.1 miles 1.2 miles 0.0 miles

3. Establishment of Motorized “Open Areas” None None None None None None None

4. Changes 

to the NFTS

a. Change in Class of Vehicles 

resulting from approval of mixed 

use

0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 miles

b. Change in Class of Vehicles 

resulting from changes in 

maintenance levels

0.0 miles 0.4 miles 0.0 miles 0.0 miles 0.4 miles 0.4 miles 0.0 miles

c. Change in Season of Use 0.0 miles 0.0 miles 3.5 miles 18.0 mi. 18.0 mi. 18.0 mi. 0.0 miles

d. Reopening Maintenance Level 

1 Roads

0.0 miles 0.0 miles 0.0 miles 0.0 miles 0.0 mi. 0.0 miles 0.0 miles

5. Amendments to the Forest Plan None None None None None None None

Total Mileage Open to Motorized Use 47.8 mi. 23.2 mi. 22.1 mi. 22.1 mi. 23.4 mi. 23.9 mi. 22.1 mi.

Percentage of Existing Routes Open for

Motor Vehicle Use

100% 49% 46% 46% 49% 50% 46%
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

770 – Tahoe National Forest

Wilderness: Affected Environment & Environmental Consequences

The Granite Chief Wilderness is the only federally designated wilderness within the Tahoe NF. The 

wilderness is 24,864 acres, and was part of Granite Chief IRA. The area is managed for primitive ROS 

recreation opportunities. Motorized vehicle use is prohibited within all federally designated wilderness 

areas. No motor vehicle routes are being proposed for addition within Granite Chief Wilderness. Three

very short road segments accessing dispersed recreation sites (0.1 miles total) within a half-mile of the 

wilderness boundary are proposed for addition to the NFTS in Alternative 6. The addition of these routes 

to the NFTS would not have a negative effect on wilderness characteristics (specifically, effects to 

solitude from vehicle noise) because of their extremely short length and very close proximity to existing 

NFTS roads. No road or trail segments are being proposed for addition within a half-mile of the Granite 

Chief Wilderness in any of the other action alternatives.

Experimental Forests: Affected Environment

There are two Experimental Forests located within the Tahoe National Forest: Onion Creek and Sagehen.

Onion Creek Experimental Forest is 2,846 acres in size and located south of Mt. Disney and the Sugar 

Bowl Ski Area. The management emphasis for this area is to continue promoting the tasks of studying the 

interrelationships between water, plants, soils and climate, as related to water quality, yield, and flow 

timing. Several roads are located within this Experimental Forest, but recreation and OHV use is not 

encouraged.

Sagehen Experimental Forest is 7,552 acres in size and located is west of State Highway 89, about six 

miles north of the town of Truckee. The management emphasis for this area ias to provide two alternative 

types of stand structure typified by even-age openings and stands managed to produce and maintain 

mature forest structure. This area includes one small campground and some designated four-wheel-drive 

trails. These recreation uses will be monitored for compatibility with the research purposes for this area.

Experimental Forests: Environmental Consequences

Onion Creek Experimental Forest

Cross Country Travel: Cross country travel is currently prohibited within the Onion Creek Experimental

Forest and would continue to be prohibited in each action alternative.

Additions to the NFTS: One motorized trail providing access to a dispersed site would be added to 

the NFTS in Alternatives 2, 5 and 6. This route is less than 0.2 mile in length and use of the route would 

be consistent with Experimental Forest management objectives. The other action alternatives do not 

propose this route and therefore would not have any effects on the Onion Creek Experimental Forest.

Establishment of Motorized “Open Areas”: Not applicable to this area; therefore, there is no effect.

Changes to the NFTS: No changes in class of vehicles are proposed in any alternative. Seasonal

restrictions would be implemented on all native surface roads and motorized trails during the wet periods 

of the year in Alternatives 4, 5 and 6. Those seasonal restrictions would be consistent with Experimental 
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Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

Tahoe National Forest – 771

Forest management objectives. No Maintenance Level 1 roads are being proposed for re-opening within 

this experimental forest in any of the action alternatives; therefore, there is no effect.

Forest Plan Amendment: Not applicable to this area; therefore, there is no effect.

Sagehen Experimental Forest

Cross Country Travel: Cross country travel is currently prohibited within the Sagehen Experimental 

Forest and would continue to be prohibited in each action alternative.

Additions to the NFTS: Within the Sagehen Experimental Forest there is one motorized trail being 

considered for addition to the NFTS. Route TKN 001 is included in Alternatives 2 and 5. This motorized 

trail is about a quarter mile in length and would connect an existing OHV trail to a system road. Without 

this connection the OHV route ends up being an out and back route which is a less preferable recreation 

opportunity. The effects from this route on the Experimental Forest are likely to be slight due to the length 

of the route. Alternatives 3, 4, 6 and 7 would have no effects because no motorized trails are proposed for 

addition to the NFTS within Sagehen Experimental Forest.

Establishment of Motorized “Open Areas”: Not applicable to this area; therefore, there is no effect.

Changes to the NFTS: No changes in class of vehicles are proposed in any alternative. Seasonal

restrictions would be implemented on all native surface roads and motorized trails during the wet periods 

of the year in Alternatives 4, 5 and 6. Those seasonal restrictions would be consistent with Experimental 

Forest management objectives. No Maintenance Level 1 roads are being proposed for re-opening within 

this experimental forest in any of the action alternatives; therefore, there is no effect.

Forest Plan Amendment: Not applicable to this area; therefore, there is no effect.

Designated and Proposed Wild and Scenic Rivers: 

Affected Environment

Designated and Proposed Wild and Scenic Rivers are managed to preserve their notable values or features

(identified as “outstandingly remarkable values”), as part of, or for eventual inclusion into the National 

Wild and Scenic River System. On the Tahoe National Forest, this management direction applies to those 

NFS lands within 1⁄4 mile on either side of the North Fork of the American River, which has a “Wild 

River” designation; and proposed sections of Sagehen Creek, Lower South Yuba River, North Yuba River 

and Canyon Creek.

There are no proposed additions to the NFTS within the North Fork of the American Wild River 

corridor, or the proposed corridors along the North Fork Yuba River and Canyon Creek. A total of less 

than one-mile of unauthorized routes is being proposed for addition to the NFTS along Sagehen Creek 

and the South Yuba River. Each of the proposed additions (12 spur routes) would provide motor vehicle 

access to dispersed recreation sites adjacent to existing NFTS routes.

Several of the action alternatives have identified seasonal restrictions during wet-weather periods for 

motor vehicle routes located within the four proposed Wild and Scenic River corridors.
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Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

772 – Tahoe National Forest

North Fork of the American River

The North Fork of the American is a federally designated Wild and Scenic River partially located on the 

Tahoe National Forest. Motor vehicle use is prohibited within the entire “Wild River” corridor (9,455 

acres). There are currently no NFTS motor vehicle routes within the river corridor and no proposed 

additions in any of the alternatives. Management of the Wild River corridor would remain unchanged as a 

result of this planning effort.

The North Fork American River was designated as a “Wild River” because it is free of impoundments 

and generally inaccessible by motor vehicles, with watersheds and shorelines essentially primitive, and 

waters unpolluted. It represents a vestige of primitive America.

Canyon Creek

A thirty-mile section of Canyon Creek was proposed for designation as a Wild and Scenic River. Within 

this corridor, 28-miles were recommended as a “Wild River” and two-miles as a “Scenic River.” The 

Canyon Creek Wild and Scenic corridor (4,565 acres) was found eligible for its “outstandingly 

remarkable” primitive and semi-primitive recreation and scenic values. The proposed Wild and Scenic 

River corridor includes 5.3 miles of NFTS roads and trails and 2.4 miles of unauthorized motor vehicle 

routes.

Canyon Creek was recommended as an addition into the National Wild and Scenic River System 

because of its identified semi-primitive/primitive recreation and scenic values as well as the historic 

mining values of the area. 

North Yuba River 

The North Yuba Proposed Wild and Scenic River includes 45 miles of river corridor (14,228 acres) that is 

eligible for its “outstandingly remarkable” fisheries, heritage resources, vegetation, scenic and recreation 

values. The river is managed as a “Recreational River” from Yuba Pass downstream to Shenanigan Flats, 

and as a “Scenic River” from Shenanigan Flats to Wambo Bar. Within this corridor there are currently 

13.3 miles of NFTS, and 10.3 miles of unauthorized motor vehicle routes included in the proposed Wild 

and Scenic River corridor. The river is easily accessible from motor vehicles, as State Highway 49 closely 

parallels 90 percent of this river segment.

The North Yuba River was recommended as an addition to the National Wild and Scenic River 

System because of the National significance of the gold mining history and State level significance of the 

fishery. In addition, the river provides a broad range of recreation opportunities, high scenic quality, and 

plant values.

Sagehen Creek

The eight-mile corridor (2,451 acres) of proposed Sagehen Creek Wild and Scenic River was found to be 

eligible for “Scenic River” designation because of its “outstandingly remarkable” ecosystem, geologic, 

fisheries, unique wildlife, and historic values. The proposed Wild and Scenic river corridor is paralleled 

by US 89 and NFTS roads. There are numerous dispersed recreation sites located adjacent to Sagehen 

Creek. Included within the proposed Wild and Scenic River corridor are 9.9 miles of NFTS roads and 

trails and 4.8 miles of unauthorized motor vehicle routes. 
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Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

Tahoe National Forest – 773

Sagehen Creek was recommended to as an addition into the National Wild and Scenic River System 

because of its outstandingly remarkable ecosystem values in the form of fens, unique plants, special 

geologic formations that support the fens, unique water chemistry that supports rare caddis flies, an 

excellent assemblage of native fisheries, unique wildlife values, and historical logging values eligible to 

the National Register of Historic Places. 

South Yuba River

Nineteen-miles of the proposed South Yuba Wild and Scenic River are located on the Tahoe NF. The river 

corridor was found to be eligible for designation because of its “outstandingly remarkable” scenic, 

recreational and cultural values. The river segment from Jordan Creek to 0.3 miles below Lang’s Crossing 

is managed as a “Recreational River”; the next segment to approximately 0.5 miles below the confluence 

of Fall Creek is managed as a “Scenic River”; and the final segment to the forest boundary is managed as 

a “Recreational River”. Included within the proposed Wild and Scenic river corridor (3,161 acres) are 5.9 

miles of NFTS motor vehicle routes and 2.4 miles of unauthorized motor vehicle routes.

The South Yuba River below Spaulding was recommended as an addition into the National Wild and 

Scenic River System because of its outstanding broad recreation opportunities and high scenic qualities, 

water associated recreation activities, and historic values.

Wild and Scenic Rivers: Environmental Consequences

The following section describes how the alternatives affect designated and proposed Wild and Scenic 

rivers using the following indicator: Outstandingly Remarkable Values as identified in the affected 

environment.

Alternative 1 (No Action)

Direct and Indirect Effects

Cross Country Travel: The No Action Alternative could degrade outstandingly remarkable values in all 

proposed Wild and Scenic river corridors because it allows the potential for cross country travel across all 

24,405 affected acres. Cross country travel with continued route proliferation could reduce scenic, 

recreational, historic, ecosystem, wildlife, plant and other values across all proposed Wild and Scenic 

River corridors. The prohibition of motor vehicle use within the 9,445 acres of the North Fork American 

Wild River would continue.

Additions to the NFTS: There would be no direct or indirect effects on proposed Wild and Scenic 

River corridors because no unauthorized routes are being proposed for addition as NFTS roads or trails in 

the No Action Alternative.

Establishment of Motorized “Open Areas”: Not applicable to designated or proposed Wild and 

Scenic Rivers.

Changes to the NFTS: There would be no direct or indirect effects on proposed Wild and Scenic 

River corridors because no changes to the NFTS regarding class of vehicle, season of use or reopening of 

ML 1 roads is proposed in this alternative.

Forest Plan Amendment: Not applicable to designated or proposed Wild and Scenic Rivers.
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774 – Tahoe National Forest

Cumulative Effects

Alternative 1 would contribute towards negative cumulative effects on designated and proposed Wild and 

Scenic Rivers because additional future route proliferation would adversely affect the identified 

outstandingly remarkable values as mentioned in the affected environment. 

Action Alternatives 

Direct and Indirect Effects

Cross Country Travel: The Action Alternatives could improve the outstandingly remarkable values in all 

proposed Wild and Scenic river corridors because it prohibits cross country travel across all 24,405 

affected acres. 

Additions to the NFTS: This is addressed for each proposed Wild and Scenic River corridors.

Establishment of Motorized “Open Areas”: Not applicable to designated or proposed Wild and 

Scenic River corridors.

Changes to the NFTS: This is addressed for each proposed Wild and Scenic River corridor if there 

are changes to the NFTS regarding class of vehicle or season of use. There will be no re-opening of ML 1 

roads in any alternative.

Forest Plan Amendment: Not applicable to designated or proposed Wild and Scenic Rivers; 

therefore, there are no effects and it will not be discussed further.

Cumulative Effects

The action alternatives would contribute towards positive cumulative effects on designated and proposed 

Wild and Scenic Rivers because decreased route proliferation would benefit the identified outstandingly 

remarkable values. 

North Fork of the American River

Cross Country Travel: Cross country travel is already prohibited within the North Fork American Wild 

and Scenic River. There is no change in any of the alternatives. Continuing the prohibition on cross 

country travel will maintain or enhance the outstandingly remarkable values of the North Fork American 

River.

Additions to the NFTS: There are no proposed additions to the NFTS in any of the alternatives.

Adding no additional roads or trails to the NFTS in North Fork American Wild River corridor would

maintain or enhance the outstandingly remarkable values of the area.

Changes in the NFTS: There is 0.1 mile of native surface road along the edge of the Wild & Scenic 

River corridor. This road is currently managed as open to all vehicles all year. Alternatives 4, 5 and 6 

impose wet weather seasonal restrictions on this road. These seasonal restrictions would be consistent 

with maintaining the outstandingly remarkable values of the North Fork American River. There are no 

changes in the class of vehicle and ML1 roads would not be re-opened in this corridor; therefore, there is 

no additional effect.

Cumulative Effects: Each of the action alternatives would enhance the outstandingly remarkable 

values associated with North Fork American River by prohibiting cross country travel within the river 
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Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

Tahoe National Forest – 775

corridor. Alternatives 4, 5 and 6 would further enhance those values by restricting use of designated motor 

vehicle routes during the wet weather season.

Canyon Creek

Cross Country Travel: Cross country travel would be prohibited on 4,565 acres within the Canyon 

Creek river corridor. The prohibition of cross country travel would prevent proliferation of unauthorized 

routes and would serve to maintain or enhance the outstandingly remarkable values of Canyon Creek. The 

prohibition of cross country travel would result in a reduction of the total amount of roads and trails 

available for motorized use 

Additions to the NFTS: There are no proposed additions to the NFTS in any of the alternatives.

Adding no new roads or trails to the NFTS would maintain or enhance the remarkably outstanding values 

associated with Canyon Creek.

Changes to the NFTS: There are no changes proposed to the class of vehicles allowed on existing 

NFTS roads in any of the alternatives. Wet weather seasonal restrictions on all native surface roads and 

trails would be imposed in Alternatives 4, 5 and 6 which would improve the current water quality 

conditions. These seasonal restrictions would enhance the outstandingly remarkable values associated 

with Canyon Creek. There are no ML1 roads being re-opened in this corridor; therefore, there is no 

additional effect. 

Cumulative Effects: Each of the action alternatives would enhance the outstandingly remarkable 

values associated with Canyon Creek by prohibiting cross country travel and reducing the amount of 

roads and trails available for motorized use within the river corridor. Alternatives 4, 5 and 6 would further 

enhance those values by restricting use of designated motor vehicle routes during the wet weather season.

North Yuba River

Cross Country Travel: Cross country travel would be prohibited on 10,634 acres within the river 

corridor in each of the action alternatives. The prohibition of cross country travel would prevent 

proliferation of additional unauthorized routes and serve to maintain or enhance the outstandingly 

remarkable values of the North Yuba River.

Additions to the NFTS: There are no proposed additions to the NFTS in any of the alternatives.

Changes to the NFTS: Wet weather seasonal restrictions on all native surface roads and trails are 

proposed in Alternatives 4, 5 and 6 which would serve to improve the current water quality conditions.

The class of vehicles allowed would be changed from “Roads open to highway legal vehicles only” to 

“Roads open to all vehicles” on 3.9 miles in Alternatives 2 and 5 and on 1.9 miles in Alternative 6. The

changes in class of vehicles that would be allowed are the result of a mixed use safety analysis. Allowing

mixed use would have no impact on identified outstandingly remarkable values. There are no ML1 roads 

being re-opened in this corridor; therefore, there is no additional effect. 

Cumulative Effects: Each of the action alternatives would serve to maintain or enhance the 

outstandingly remarkable values associated with North Yuba River by prohibiting cross country travel and 

reducing the amount of roads and trails available for motorized use within the river corridor. Alternatives 
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Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

776 – Tahoe National Forest

4, 5 and 6 would further enhance those values by restricting use of designated motor vehicle routes during 

the wet weather season.

Sagehen Creek

Cross Country Travel: Cross country travel would be prohibited on 2,165 acres within the river corridor 

in each action alternative. The prohibition of cross country travel would prevent the proliferation of 

unauthorized routes and serve to maintain or enhance the outstandingly remarkable values identified for 

Sagehen Creek. The prohibition of cross country travel would result in a reduction of the total amount of 

roads and trails available for motorized use in each action alternative. Reducing the total miles of routes 

available for motor vehicle use would enhance the outstandingly remarkable values associated with 

Sagehen Creek.

Additions to the NFTS: Alternatives 3, 4 and 7 would not include any additions to the NFTS. 

Alternatives 2 and 5 propose the addition of 3 spur roads to the NFTS totaling 300 feet. The average 

length of these roads is 100 feet. These roads all come off existing NFTS roads to provide access to 

dispersed recreation sites. Alternative 6 proposes the addition of 4 roads to the NFTS totaling .1miles. The 

average length of these roads is 160 feet. These roads also come off existing NFTS roads to provide 

access to dispersed recreation sites. No substantial resource concerns were identified for these proposed 

additions to the NFTS. The designation of these short spur roads accessing dispersed recreation sites 

would have minor negative effects to the outstandingly remarkable values associated with Sagehen Creek.

Changes to the NFTS: Wet weather seasonal restrictions on all native surface roads and trails would

be imposed in Alternatives 4, 5 and 6. Those restrictions would serve to improve the current water quality 

conditions and therefore enhance the outstandingly remarkable values associated with Sagehen Creek.

The class of vehicles allowed would be changed from “Roads open to highway legal vehicles only” to 

“Roads open to all vehicles” on 2.1 miles in Alternatives 2, 5 and 6. The proposed changes in vehicle 

class allowed is the result of a mixed use analysis as described in Appendix J. Allowing mixed use 

identified NFTS roads would have no impact of the rivers outstandingly remarkable values. There are no

ML1 roads being re-opened in this corridor; therefore, there is no additional effect. 

Cumulative Effects: Each of the action alternatives would maintain or enhance the outstandingly 

remarkable values associated with Sagehen Creek by prohibiting cross country travel and reducing the 

amount of roads and trails available for motorized use within the river corridor. Alternatives 4, 5 and 6 

would further enhance those values by restricting use of designated motor vehicle routes during the wet 

weather season.

South Yuba River

Cross Country Travel: Cross country travel would be prohibited on 3,161 acres within the river corridor 

in all of the action alternatives. Each action alternatives would reduce the number of miles of roads and 

trails available for motorized use. The reduction in mileage of routes available for motor vehicle use 

would enhance the high scenic quality associated with the South Yuba River. 

Additions to the NFTS: Alternatives 3, 4 and 7 would not include any additions to the NFTS. 

Alternatives 2, 5 and 6 propose the addition of 8 spur roads to the NFTS totaling .5 miles. The average 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

Tahoe National Forest – 777

length of these roads is 322 feet. These roads all come off existing NFTS roads to provide access to 

dispersed recreation sites within the “Recreational River” corridor. These short spur roads accessing 

dispersed recreation sites would serve to maintain or enhance the outstandingly remarkable values 

associated with South Yuba River by providing opportunities for motorized access to visitors for 

enjoyment of the recreation and scenic values associated with the South Yuba River.

Changes to the NFTS: The class of vehicles allowed would be changed from “Roads open to 

highway legal vehicles only” to “Roads open to all vehicles” on three tenths of a mile in Alternatives 2, 5 

and 6. These changes in class of vehicles allowed are the result of a mixed use analysis as described in 

Appendix J. Allowing mixed use on these existing NFTS roads would have no impact of the rivers 

outstandingly remarkable values. Wet weather seasonal restrictions on all native surface roads and trails 

would be imposed in Alternatives 4, 5 and 6 which would improve the current water associated recreation 

activities values of the South Yuba River. There are no ML1 roads being re-opened in this corridor; 

therefore, there is no additional effect. 

Cumulative Effects: Each of the action alternatives would serve to maintain or enhance the 

outstandingly remarkable values associated with South Yuba River by prohibiting cross country travel and 

reducing the amount of roads and trails available for motorized use within the river corridor. Alternatives 

4, 5 and 6 would further enhance those values by restricting use of designated motor vehicle routes during 

the wet weather season.

Research Natural Areas: 

Affected Environment and Environmental Consequences

The Forest has three areas: Lyon Peak/Needle Lake (700acres) located on the northern boundary of 

Granite Chief Wilderness, Sugar Pine Point (625 acres) located about 4 miles due south of Cisco Grove 

just north of the North Fork American River; and Babbitt Peak (1061 acres) located north and west of 

Babbitt Peak on the Sierraville District. Babbitt Peak was designated for the distinctive and unusual 

occurrence of Washoe pine and mature stands of mountain mahogany and their significant potential for 

research and ecological study. Sugar Pine Point was designated for the good examples of the various 

stages of succession in a mixed conifer forest and the area represents a zone of overlap of ponderosa pine 

and Jeffrey pine. Lyon Peak was designated for the Mountain Hemlock and several other uncommon

plants that provide high potential for research and ecological study. Motor vehicles are excluded from all 

three of these areas. No changes in management of these RNAs will occur under any alternative. There 

are no environmental consequences associated with RNAs in any of the alternatives. 

Special Interest Areas: 

Affected Environment and Environmental Consequences

The 1990 Forest Land and Resource Management Plan designated 7 Special Interest Areas (SIA). Each 

area has specific language that may or may not permit some level of OHV use. In general due to the 

special nature of each of these areas, OHV trails would either be excluded or not encouraged. The Special 

Interest Areas are: Placer County Big Tree Grove Botanical Area (346 acres), Devils Postpile Geologic 
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Chapter 3: Affected Environment & Environmental Consequences – 3.09. Inventoried Roadless Areas & Special Areas

778 – Tahoe National Forest

Area (69 acres), Glacier Meadow Geologic Area (84 acres), Grouse Falls Scenic Area (220), Meadow 

Lake Cultural Area (58 acres), Sagehen Headwaters (79 acres), and Mason Fen (30) acres. If an OHV trail 

is proposed within a SIA the land management plan direction and land allocation would have to be 

considered to determine if a trail was allowable and or appropriate. No changes in management of these 

SIAs will occur under any alternative. There are no environmental consequences associated with SIAs in 

any of the alternatives.

Summary of Effects Analysis across All Alternatives

This section summarizes the effects analysis for roadless and special areas for each measurement 

indicator. Table 3.09-19 summarizes the effects analysis for special areas by ranking each alternative 

based on negative or positive impacts that could occur from proposed management actions. A score of one 

indicates that the alternative would have the most negative impact to Special Area resources; while a 

score of seven identifies the alternative that would be most beneficial to those resources.

Table 3.09-19 Summary Table – Special Areas – Tahoe NF

Impact to Special Area Resources Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

All IRAs, Experimental Forest, W & S Rivers 1 3 5 7 2 6 4
Chapter 3.10 

Adjacent Ownerships 

Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010 

3.10. Adjacent Ownerships _______________________________ 

Affected Environment 

Adjacent Lands of Other Ownerships 

Compatibility between the management of National Forests and the management of adjacent private land 

is important in reducing conflicts. Within the established boundaries of the Tahoe National Forest (TNF) 

are approximately 381,000 acres of privately owned land, with parcels varying in size from about 5 acres 

to over 12,000 acres. Additional private land adjoins the Forest’s exterior boundary and along interior 

inclusions (i.e., areas of private land excluded when the TNF was established). More than 2,700 miles of 

property boundary interface between the National Forest System (NFS) and private land. 

The checkerboard pattern of ownership in this area results from the railroad land grants of the 1860’s, 

which were intended to encourage the construction of railroads and schools by granting alternate sections 

of land to the railroads and the States. The majority of this land is currently owned by Sierra Pacific 

Industries and other timber land managing companies, resulting in about 2,000 miles of property 

boundaries between them and the TNF. Many cooperative agreements for road construction and 

maintenance have been entered into with adjacent land owners; many of which allow for public access 

across private land. Sierra Pacific Industries (SPI) manages more than 250,000 acres in the Sierra Nevada. 

They are the largest corporate land owner in the TNF. SPI has stated that they are opposed to public offhighway vehicle (OHV) use on their lands. The assumption has been made in estimating environmental 

effects in this EIS that SPI corporate forest roads would not be available for use by the public. 

Scattered throughout the TNF are smaller parcels and tracts of privately owned land. These parcels 

are mostly the result of homesteads, Native American Allotments, mineral patents, and State School land 

sales. These small parcels are typically 5 to 100 acres with irregular shapes. 

Different land ownerships, by themselves, do not create conflict in regards to public access by 

wheeled motor vehicles. Different land ownership objectives often do create conflict, even on lands in the 

same ownership. Opportunities to coordinate with intermingled and adjacent land owners will continue, 

underlining the importance of developing compatible road and trail management objectives between 

private and NFS lands. 

Recently, more encroachment and trespassing have occurred along the National Forest/private 

property boundaries, resulting in user-created routes existing on private land. Several of the unauthorized 

routes under consideration for addition to the NFTS and closed NFTS roads proposed for reopening are 

on the other side of private lands through which the Forest Service does not have a valid right of way. 

None of the alternatives add roads or motorized trails to the NFTS on private land without a valid right of 

way. All additions to the NFTS lie wholly on NFS lands. However, providing additional NFTS motorized 

recreation opportunities on the other side of private land could have an impact on the private landowners 

whose land would need to be crossed to get to those opportunities. Prior to making any additions to the 

NFTS on NFS lands on the other side of these private lands, mitigation measures are specified in 

Appendix A (Site Specific Road, Trail and Open Area Information) that permission must first be obtained 

from the private land owner to grant public access. Once this permission is obtained, the portion of the 

Tahoe National Forest – 779 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010 

Chapter 3: Affected Environment and Environmental Consequences – 3.10. Adjacent Ownerships 

roads and/or trail on NFS lands would be added to the NFTS and then made available for public access. 

Prior to the permission being obtained, public use of these roads and trails would be prohibited. If the 

land owner is unwilling to give permission for public access, the portion of those routes on NFS lands 

would not be added to the NFTS and public use would be prohibited on them. Routes on the other side of 

lands owned by SPI were excluded from this consideration unless the Forest Service already has a rightof-way or easement. Table 3.10-1 lists those roads and trails on NFS lands which could be added to the 

NFTS once permission from the private land owner is obtained for public access through their lands. 

Table 3.10-1. Routes Potentially Affecting Private Land under Consideration for Addition to the NFTS 

Route ID Description of Need as Part of the NFTS 

ARM-5 Trail connecting two routes near Eliot Meadow which connects two National Forest System Roads. 

H29-11 Former NFTS road coming off of the 29 Road to the north near Omega going into and dead ending 

on private land. The majority of the route is on private land. 

H293 Former NFTS road on Sleighville Ridge northeast of Camptonville parallel to County Road Road 115 

accessing private land at Sleighville House. 

H293-19 Former NFTS road 293-19 coming off of County road 293 north of Miller Ranch. First part of road 

crosses private land. 

H293-4-18 Former NFTS road south of Henness Pass road accessing private land at Gates Orchard. 

H34-4 Former NFTS road number 34-4. Makes a small loop to the north off of the Jouberts Road just south 

of Indian Hill and Highway 49 near Indian Valley. Short segment crosses private land immediately 

adjacent to the Jouberts Road. 

H34-8-3 Former NFTS road accessing dispersed recreation site on private land in Indian Valley just south of 

Highway 49. 

H36-3-1 Former NFTS road east of Malakoff Diggings in Missouri Canyon which makes a loop between two 

National Forest System roads. One small segment crosses private land near Humbug Creek. 

H38 Former NFTS road north of the Sugar Pine Flat Research Natural Area coming off National Forest 

System road number 38 accessing private land at Pelliam Flat. 

H823-1-1 Former NFTS road west of Gold Lake coming of National Forest System road number 9 to the north 

accessing private land at Howard Creek Meadows. 

H833 Former NFTS road west of Malakoff Diggings near Bloody Run. Short segment near intersection with 

County Road 522 crosses private land. 

H88-13 Former NFTS road just south of China Flat OHV staging area connecting a NFTS motorcycle trail 

with Placer County road 88. Majority of route is on private land. 

N25-1-1 Former NFTS road number 25-1-1 connecting NFTS road number 25 just north of Cal-Ida to NFTS 

road number 25-1. Short segment near junction with the NFTS road 25-1 crosses private land. 

N96-12c Former NFTS road coming north off of the Mosquito Ridge Road near Mosquito Narrows. One 

segment dead ends at Cedar Springs and the other segment dead ends at Big Oak Flat. 

TKN-J4 This trail accesses Andesite Peak and has views along the way. 

TKN-J9 This trail follows a powerline and provides an alternative route to other nearby routes with safety 

concerns. 

780 – Tahoe National Forest 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010 

Chapter 3: Affected Environment and Environmental Consequences – 3.10. Adjacent Ownerships 

Route ID Description of Need as Part of the NFTS 

TKN-Q1 This trail is located on top of a buried phone line. It parallels an existing trail that was meant to reroute users; however, some users prefer to follow the buried line rather than the alternative system 

trail. 

YRM-M4 Comes off of Sierra County road number 201 south of the town of Alleghany. Accesses private land 

at Minnesota Flat. 

YRN-M3b Motorcycle trail connecting the Downie River Trail to Castle Rock Trail. Crosses small segment of 

private land near Castle Rock Trail. 

YRS-AF South of Fordyce Lake. Comes off of NFTS motorcycle trail and provides access to a small lake. 

Short segment near intersection with existing trail crosses private land. 

YRS-SF5 Comes off of Highway 20 to the north near Bear Valley. One curve in trail touches a parcel of private 

land. 

Adjacent National Forest System Land 

The TNF adjoins three other National Forests: Plumas, Eldorado, Humboldt-Toiyabe, as well as the Lake 

Tahoe Basin Management Unit (LTBMU). Shared administrative duties often occur along the Forest 

boundaries. The TNF, for example, currently administers a small portion of the Plumas National Forest 

northeast of Bullards Bar Reservoir. This shared administration is intended primarily to facilitate 

efficient, economical management of NFS land. Adjacent National Forests currently have coordinated 

travel management planning to ensure the amount of contrast between respective National Forests is 

minimized. 

Private Land Interface 

Private land interface situations may occur when NFS lands are adjacent to private lands that have been, 

or may be, developing for recreation, rural, residential, urban or commercial uses. When National Forest 

road and trail management objectives differ from our neighbors, the potential for mutual conflicts exist. 

Generally these private land interface conflicts arise adjacent to private lands where the land owners have 

conflicting road and trail management objectives and different perceptions about how NFS roads and 

trails adjacent or near their property should be managed. Typically these lands range from small 

communities, towns, and subdivisions to scattered rural residences. Some of these private land owners are 

concerned that the effects of Forest Service road and trail management will have negative effects on water 

quality, noise, dust, and recreation opportunities. As a result of these concerns, often private land owners 

are opposed to motor vehicle use, trespassing by recreationists, and road maintenance. Many people feel 

the Forest should provide buffers on NFS lands. To add to this complexity, land owners may have 

conflicting needs and attitudes about management of roads and trails next to them. One land owner may 

be completely supportive of adjoining motorized recreation opportunities while another resident may be 

totally opposed due aesthetic concerns, noise, or dust drifting onto their property. 

Residential and community development of private lands adjacent to National Forest boundaries is 

expanding. The Sierra Nevada foothill counties are the fastest growing in the State. It is predicted that, 

through the subdivision of private lands, the number of land owners within and adjacent to National 

Forest boundaries will significantly increase. The number of land owners with different road and trail 

management objectives and perceptions about how NFS roads and trails should be managed will also 

Tahoe National Forest – 781 
 

 

 

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Chapter 3: Affected Environment and Environmental Consequences – 3.10. Adjacent Ownerships 

increase dramatically. Table 3.10-2 displays the current miles of roads and trails within the Urban/Rural/ 

Wildland Interface (1⁄4 mile of private land, 1990 LRMP) by class of vehicle and season of use. 

Table 3.10-2. Motorized Roads and Trails within Urban/Rural/Wildland Interface 

Road/Trail Category Season of Use Length (miles) 

Cross Country Travel 

Acres 

Unauthorized routes and closed NFTS roads still receiving some motorized 

use (miles) 

N/A 268,400 

596.2 

NFTS Roads open to highway legal vehicles only (miles) Open Seasonally 72.9 

Open Year Around 79.8 

NFTS Roads open to all vehicles (miles) 

Seasonal Closure 106.0 

Open Year Around 329.7 

NFTS Trails open to high clearance trail vehicles (miles) 

Seasonal Closure 4.8 

Open Year Around 19.5 

NFTS Trails open to ATVs and motorcycles only (miles) 

Seasonal Closure .5 

Open Year Around 3.6 

NFTS Trails open to motorcycles only (miles) 

Seasonal Closure 3.9 

Open Year Around 22.3 

Subtotal NFTS Motorized Roads & Trails 642.9 

State, County or other jurisdiction roads Open Year Around 209.0 

Private Roads Open Year Around 6.2 

Total Motorized 1,454.3 

Local Plans and Initiatives 

County plans, zoning plans: All county plans in the State of California affect all of the private roads 

within county boundaries. In the counties in the TNF, private lands adjacent to National Forests are 

generally zoned for very low housing densities (one dwelling per 160 or 640 acres). The regulations for 

these zones keep roads available for use by the public consistent with the California Vehicle Code. 

There will be little effect on county planning from the decisions made from this project. County 

zoning and regulations are only peripherally affected by TNF management. County plans and zoning are 

primarily based on locations of existing infrastructure, distance to schools, services, utilities, and land 

capabilities. There are no direct ties between these plans and route designations on the TNF, so the effects 

from the decisions made by this project on county plans and the effect of county plans on this decision are 

minimal. 

Other Federal Lands 

The Bureau of Land Management has a multiple-use management mission, similar to that of the Forest 

Service, and the agency’s management plans reflect stewardship commitments comparable to those that 

apply to the National Forests. The Forest Service coordinates management activities and planning at 

various geographic scales with the Bureau of Land Management, including travel management. 

782 – Tahoe National Forest 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010 

Chapter 3: Affected Environment and Environmental Consequences – 3.10. Adjacent Ownerships 

State Parks 

Units of the California State Park system, that are in the Sierra Nevada, protect all their wildlife and 

plants and give special care to sensitive species. State Parks have regulations that prohibit any disturbance 

or destruction of natural resources. The Forest Service coordinates management activities and planning at 

various geographic scales with the State Parks, including travel management. 

Environmental Consequences 

Measures or Factors Used to Assess Environmental Consequences 

Management activities proposed in all of the alternatives could directly, indirectly, or cumulatively affect 

adjacent ownerships. National Forest travel management decisions have the potential to affect adjacent 

ownerships. The following factors indicate potential effects on adjacent ownerships: 

1. Adding motorized roads and trails to the NFTS on the other side of private land, 

2. Management of wheeled motorized vehicle activities adjacent to private 

1. Motorized Roads and Trails on the Other Side of Private Land 

Several of the unauthorized routes under consideration for addition to the NFTS are on the other side of 

private land. In addition, some of the Maintenance Level 1 roads proposed for reopening are also on the 

other side private lands. Allowing public motorized use on these routes on the other side of private land 

could have an impact on the private landowners. Before these routes, on the other side of private land, are 

designated for public motorized use, permission must first be obtained from the private land owner to 

grant public access. Prior to the permission being obtained, public use of these routes on the other side of 

private land would be prohibited. If the land owner is unwilling to give permission for public access, 

these routes would not be available for public use. Routes on the other side of lands owned by Sierra 

Pacific Industries (SPI) were excluded from this consideration unless the Forest Service already has a 

right-of-way or easement since they have indicated they are unwilling to encourage use by public 

motorized vehicles on their land. Table 3.10-3 lists those NFTS roads and trails on the other side of 

private land which would be made available for public motorized use once permission from the private 

land owner is obtained for public access. 

Tahoe National Forest – 783 
 

 

 

 

 

 

 

 

 

 

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Chapter 3: Affected Environment and Environmental Consequences – 3.10. Adjacent Ownerships 

Table 3.10-3. Additions to the NFTS and Reopening of Maintenance Level 1 roads on the other side of Private 

Land by Alternative 

Action 

Proposed 

Route ID Description Alt 11 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7 

Additions 

to the 

NFTS 

ARM-5 Trail connecting two routes near Eliot Meadow 

which connects two NFTS roads. X X X X X 

H29-11 Former NFTS road coming off of the 29 Road to the 

north near Omega going into and dead ending on 

private land. The majority of the route is on private 

land. 

X X 

H293 Former NFTS road on Sleighville Ridge northeast of 

Camptonville parallel to County Road Road 115 

accessing private land at Sleighville House. 

X X 

H293-4-18 Former NFTS road south of Henness Pass road 

accessing private land at Gates Orchard. X X 

H34-8-3 Former NFTS road accessing dispersed recreation 

site on private land in Indian Valley just south of 

Highway 49. 

X X 

H36-3-1 Former NFTS roads east of Malakoff Diggings in 

Missouri Canyon which makes a loop between two 

NFTS roads. One small segment crosses private 

land near Humbug Creek. 

X X 

H833 Former NFTS road west of Malakoff Diggings near 

Bloody Run. Short segment near intersection with 

County road 522 crosses private land. 

X X 

H88-13 Former NFTS road just south of China Flat OHV 

staging area connecting a National Forest System 

motorcycle trail with Placer County road 88. Majority 

of route is on private land. 

X X 

TKN-J4 This trail accesses Andesite Peak and has views 

along the way. X X X X X 

TKN-J9 This trail follows a powerline and provides an 

alternative route to other nearby routes with safety 

concerns. 

X X X X X X 

TKN-Q1 This trail is located on top of a buried phone line. It 

parallels an existing trail that was meant to re-route 

users; however, some users prefer to follow the 

buried line rather than the alternative system trail. 

X X X X 

YRM-M4 Comes off of Sierra County road number 201 south 

of the town of Alleghany. Accesses private land at 

Minnesota Flat 

X X X X X 

YRN-M3b Motorcycle trail connecting the Downie River Trail to 

Castle Rock Trail. Crosses small segment of private 

land near Castle Rock Trail. 

X X X X 

YRS-AF South of Fordyce Lake. Comes off of National 

Forest System motorcycle trail and provides access 

to a small lake. Short segment near intersection with 

existing trail crosses private land. 

X X X X X X 

YRS-SF5 Comes off of Highway 20 to the north near Bear 

Valley. One curve in trail touches a parcel of private 

land. 

X X X X X X 

Subtotal Number of Road/Trail Additions to the NFTS 15 8 0 4 15 6 7 

1

 Alternative 1 does not propose any additions to the NFTS or reopening of maintenance level 1 roads, the numbers 

shown indicate the continued use of routes unauthorized for public motorized access 

784 – Tahoe National Forest 
 

 

 

 

 

 

 

 

 

Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010 

Chapter 3: Affected Environment and Environmental Consequences – 3.10. Adjacent Ownerships 

Action 

Proposed 

Route ID Description Alt 11 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7 

Reopening 

ML 1 

Roads 

N96-12c Maintenance Level 1 NFTS road coming north off of 

the Mosquito Ridge Road near Mosquito Narrows. 

One segment dead ends at Cedar Springs and the 

other segment dead ends at Big Oak Flat. 

X X 

N25-1-1 Maintenance Level 1 NFTS road number 25-1-1 

connecting NFTS road number 25 just north of CalIda to National Forest System road number 25-1. 

Short segment near junction with the 25-1 Road 

crosses private land. 

X X 

H823-1-1 Maintenance Level 1 NFTS road west of Gold Lake 

coming of National Forest System road number 9 to 

the north accessing private land at Howard Creek 

Meadows. 

X X 

H38 Maintenance Level 1 NFTS road north of the Sugar 

Pine Flat Research Natural Area coming off NFTS 

road number 38 accessing private land at Pelliam 

Flat. 

X X 

H34-4 Maintenance Level 1 NFTS road number 34-4. 

Makes a small loop to the north off of the Jouberts 

Road just south of Indian Hill and Highway 49 near 

Indian Valley. Shorth segment crosses private land 

immediately adjacent to the Jouberts Road. 

X X 

H293-19 Maintenance Level 1 NFTS road 293-19 coming off 

of County Road 293 north of Miller Ranch. First part 

of road crosses private land. 

X X 

Subtotal Reopening ML 1 Roads 6 6 

Number of Routes Requiring Access Through Private Land 21 8 0 4 21 6 7 

Under the No Action Alternative, unauthorized use by wheeled motorized vehicles on all of the roads 

and trails listed in Table 3.10-3 would be expected to continue unless action was taken by the private land 

owner to stop public access. Alternative 3 would prohibit use by wheeled motorized vehicles on all routes 

unauthorized for motor vehicles on NFS lands which are on the other side of private land. Alternatives 2, 

4, 6 and 7 have a minor amount of unauthorized roads and trails on the other side of private land where 

use by wheeled motorized vehicles would be allowed to continue. Alternative 5 has 21 routes on the other 

side of private land where use by wheeled motorized vehicles would be allowed to continue. This use, 

however, would only be allowed once the private land owner has given permission for public access. 

Prior to such permission being given, public use by wheeled motorized vehicles would be prohibited. 

Alternative 1 

Cross Country Travel: Cross country travel is not prohibited in Alternative 1. This cross country travel 

could result in additional unauthorized trespass onto private land by wheeled motor vehicles. This 

trespass could create conflicts with the private land owners. 

Additions to the NFTS: There are no additions of any roads, trails, or areas to the NFTS in 

Alternative 1. 

Establishment of Motorized “Open Areas”: “Open Areas” would not be established in Alternative 

1. There would be no potential adverse impacts on adjacent private land owners from this element. 

Tahoe National Forest – 785 
 

 

Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010 

Chapter 3: Affected Environment and Environmental Consequences – 3.10. Adjacent Ownerships 

Changes to the NFTS: There are no changes to the NFTS in this alternative. 

Amendments to the Forest Plan: There are no amendments to the Forest Plan in this alternative. 

Cumulative Effects: Alternative 1 would have the greatest cumulative effect on adjacent private 

lands. Wheeled public motorized use on all 21 routes on the other side of private land would not be 

prohibited. In addition, not prohibiting cross country travel could result in the proliferation of more 

trespass onto private land. 

Alternative 2 

Cross Country Travel: Cross country travel would be prohibited in Alternative 2. This would limit the 

proliferation of new unauthorized routes onto private lands. This prohibition would have a positive effect 

on adjacent land owners. 

Additions to the NFTS: Alternative 2 proposes to add 8 unauthorized routes to the NFTS on the 

other side of private land. The mitigation measures specified in Appendix A (Site Specific Road, Trail and 

Open Area Information) require that permission from the private land owner granting public access first 

be obtained prior to designating these routes on the motor vehicle use map. 

Establishment of Motorized “Open Areas”: None of the “Open Areas” being established in this 

alternative are on the other side of private land. There would be no potential adverse impacts on adjacent 

private land owners from this element. 

Changes to the NFTS: Alternative 2 would not reopen any Maintenance Level 1 (ML 1) roads on the 

other side of private land. Changing the season of use or class of vehicles on NFTS roads and motorized 

trails crossing private land are not anticipated to effect adjacent ownerships. 

Amendments to the Forest Plan: The Forest Plan Amendment would not impact private land. 

Cumulative Effects: Alternative 2 would reduce the impacts on private land by prohibiting cross 

country travel and reducing the number of routes on the other side of private land requiring permission 

from the land owner from 21 to 8. 

Alternative 3 

Cross Country Travel: Cross country travel would be prohibited in Alternative 3. This would limit the 

proliferation of new unauthorized routes onto private lands. This prohibition would have a positive effect 

on adjacent land owners. 

Additions to the NFTS: There would be no proposed additions of any roads trails or areas to the 

NFTS in Alternative 3. 

Establishment of Motorized “Open Areas”: “Open Areas” would not be established in Alternative 

3. There would be no potential adverse impacts on adjacent private land owners from this element. 

Changes to the NFTS: There would be no changes to the NFTS in this alternative. Changing the 

season of use or class of vehicles on NFTS roads and motorized trails crossing private land are not 

anticipated to effect adjacent ownerships. 

Amendments to the Forest Plan: There would be no amendments to the Forest Plan in this 

alternative. 

786 – Tahoe National Forest 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010 

Chapter 3: Affected Environment and Environmental Consequences – 3.10. Adjacent Ownerships 

Cumulative Effects: Alternative 3 would reduce the impacts on access across private land by 

prohibiting cross country travel and reducing the number of routes on the other side of private land 

requiring permission from the land owner from 21 to zero. 

Alternative 4 

Cross Country Travel: Cross country travel would be prohibited in Alternative 4. This would limit the 

proliferation of new unauthorized routes onto private lands. This prohibition would have a positive effect 

on adjacent land owners. 

Additions to the NFTS: Alternative 4 proposes to add 4 unauthorized routes to the NFTS on the 

other side of private land. The mitigation measures specified in Appendix A (Site Specific Road, Trail and 

Open Area Information) require that permission from the private land owner granting public access first 

be obtained prior to designating these routes on the motor vehicle use map. 

Establishment of Motorized “Open Areas”: “Open Areas” would not be established in Alternative 

4. There would be no potential adverse impacts on adjacent private land owners from this element. 

Changes to the NFTS: Alternative 4 would not reopen any ML 1 roads on the other side of private 

land. Changing the season of use or class of vehicles on NFTS roads and motorized trails crossing private 

land are not anticipated to effect adjacent ownerships. 

Amendments to the Forest Plan: There would be no amendments to the Forest Plan in this 

alternative. 

Cumulative Effects: Alternative 4 would reduce the impacts on access across private land by 

prohibiting cross country travel and reducing the number of routes on the other side of private land 

requiring permission from the land owner from 21 to 4. 

Alternative 5 

Cross Country Travel: Cross country travel would be prohibited in Alternative 5. This would limit the 

proliferation of new unauthorized routes onto private lands. This prohibition would have a positive effect 

on adjacent land owners. 

Additions to the NFTS: Alternative 5 proposes to add 15 unauthorized routes to the NFTS on the 

other side of private land. The mitigation measures specified in Appendix A (Site Specific Road, Trail and 

Open Area Information) require that permission from the private land owner granting public access first 

be obtained prior to designating these routes on the motor vehicle use map. 

Establishment of Motorized “Open Areas”: “Open Areas” would not be established in Alternative 

5. There would be no potential adverse impacts on adjacent private land owners from this element. 

Changes to the NFTS: Alternative 5 would reopen 6 ML 1 roads on the other side of private land. 

The mitigation measures specified in Appendix A (Site Specific Road, Trail and Open Area Information) 

require that permission from the private land owner granting public access first be obtained prior to 

designating these routes on the motor vehicle use map. Changing the season of use or class of vehicles on 

NFTS roads and motorized trails crossing private land are not anticipated to effect adjacent ownerships. 

Amendments to the Forest Plan: The Forest Plan Amendment would not impact private land. 

Tahoe National Forest – 787 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010 

Chapter 3: Affected Environment and Environmental Consequences – 3.10. Adjacent Ownerships 

Cumulative Effects: Alternative 5 would reduce the impacts on access across private land by 

prohibiting cross country travel and requiring permission from the private land owners for the 21 routes 

on the other side of private land prior to their being designated on the motor vehicle use map. 

Alternative 6 

Cross Country Travel: Cross country travel would be prohibited in Alternative 6. This would limit the 

proliferation of new unauthorized routes onto private lands. This prohibition would have a positive effect 

on adjacent land owners. 

Additions to the NFTS: Alternative 6 proposes to add 6 unauthorized routes to the NFTS on the 

other side of private land. The mitigation measures specified in Appendix A (Site Specific Road, Trail and 

Open Area Information) require that permission from the private land owner granting public access first 

be obtained prior to designating these routes on the motor vehicle use map. 

Establishment of Motorized “Open Areas”: None of the “Open Areas” being established in this 

alternative are on the other side of private land. There would be no potential adverse impacts on adjacent 

private land owners from this element. 

Changes to the NFTS: Alternative 6 would not reopen any ML 1 roads on the other side of private 

land. Changing the season of use or class of vehicles on NFTS roads and motorized trails crossing private 

land are not anticipated to effect adjacent ownerships. 

Amendments to the Forest Plan: The Forest Plan Amendment would not impact private land. 

Cumulative Effects: Alternative 6 would reduce the impacts on access across private land by 

prohibiting cross country travel and reducing the number of routes on the other side of private land 

requiring permission from the land owner from 21 to 6. 

Alternative 7 

Cross Country Travel: Cross country travel would be prohibited in Alternative 7. This would limit the 

proliferation of new unauthorized routes onto private lands. This prohibition would have a positive effect 

on adjacent land owners. 

Additions to the NFTS: Alternative 7 proposes to add 7 unauthorized routes to the NFTS on the 

other side of private land. The mitigation measures specified in Appendix A (Site Specific Road, Trail and 

Open Area Information) require that permission from the private land owner granting public access first 

be obtained prior to designating these routes on the motor vehicle use map. 

Establishment of Motorized “Open Areas”: “Open Areas” would not be established in Alternative 

7. There would be no potential adverse impacts on adjacent private land owners from this element. 

Changes to the NFTS: Alternative 7 would not reopen any ML 1 roads on the other side of private 

land. Changing the season of use or class of vehicles on NFTS roads and motorized trails crossing private 

land are not anticipated to effect adjacent ownerships. 

Amendments to the Forest Plan: There would be no amendments to the Forest Plan in this 

alternative. 

788 – Tahoe National Forest 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010 

Chapter 3: Affected Environment and Environmental Consequences – 3.10. Adjacent Ownerships 

Cumulative Effects: Alternative 2 would reduce the impacts on access across private land by 

prohibiting cross country travel and reducing the number of routes on the other side of private land 

requiring permission from the land owner from 21 to 7. 

2. Management of wheeled motorized vehicle activities adjacent to private land 

Private land interface situations may occur when NFS lands are adjacent to private lands that have been, 

or may be, developed for recreation, rural, residential, urban or commercial uses. When National Forest 

road and trail management objectives differ from our neighbors, the potential for mutual conflicts exist. 

Generally these private land interface situations arise adjacent to private lands where the land owners 

have conflicting road and trail management objectives and different perceptions about how NFS roads 

and trails adjacent or near their property should be managed. 

All of the action alternatives reduce the number of miles of roads and trails open to wheeled 

motorized vehicles within 1⁄4 mile of private land (Urban/Rural/Wildland Interface, 1990 LRMP). The 

largest decrease is Alternative 3. The smallest decrease is in Alternative 5. In addition, all of the action 

alternatives prohibit cross country travel within 1⁄4 mile of private land which will reduce the proliferation 

of additional unauthorized routes. Alternatives 4, 5 and 6 impose wet weather restrictions on all native 

surface roads and trails which limit their use to the summer months. 

Alternative 1 

Cross Country Travel: Cross country travel would not be prohibited in Alternative 1 on 268,400 acres 

within 1⁄4 mile of private land. Cross country travel would also result in the continued use of 

approximately 596.2 miles of unauthorized routes within 1⁄4 mile of private land. This use would create 

conflicts with the private land owners. 

Additions to the NFTS: There would be no addition of any roads trails or areas to the NFTS in 

Alternative 1. Since there would be no additions, there would be no potential adverse impacts on adjacent 

land owners from this element. 

Establishment of Motorized “Open Areas”: “Open Areas” would not be established within 1⁄4 mile 

of private land in Alternative 1. There would be no potential adverse impacts on adjacent private land 

owners from this element. 

Changes to the NFTS: There would be no changes to the NFTS in this alternative. 

Amendments to the Forest Plan: There would be no amendments to the Forest Plan in this 

alternative. 

Cumulative Effects: Alternative 1 would have the greatest cumulative effect on lands within 1⁄4 mile 

of adjacent private land. The amount of mileage available for wheeled motorized use remains at 1,454.3 

miles. It would not prohibit cross country travel on 268,400 acres within 1⁄4 mile of private land. 

Alternative 2 

Cross Country Travel: Cross country travel would be prohibited in Alternative 2. This would limit the 

proliferation of new unauthorized routes adjacent to private lands. The prohibition of cross country travel 

Tahoe National Forest – 789 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010 

Chapter 3: Affected Environment and Environmental Consequences – 3.10. Adjacent Ownerships 

would also result in reducing use on all unauthorized roads, trails and areas not added to the NFTS. These 

changes would have a positive effect on adjacent land owners. 

Additions to the NFTS: Alternative 2 would add an additional 16.3 miles of motorized trails within 

1⁄4 mile of private land to the NFTS. These additional roads and motorized trails would have the potential 

to have adverse effects to the adjacent land owners. 

Establishment of Motorized “Open Areas”: Two areas totaling 35.3 acres would be established as 

“Open Areas” within 1⁄4 mile of private land. These additional established “Open Areas” would increase 

the potential for adverse effects to the adjacent land owners. 

Changes to the NFTS: Alternative 2 would approve mixed use on 63.7 miles of NFTS within 1⁄4 mile 

of private land. Due to increased motor vehicle use this would have an adverse impact on adjacent land 

owners. It would also change the class of vehicle on 38.6 miles of NFTS within 1⁄4 mile of private land as 

a result of changed maintenance levels. This would result in additional noise and dust impacts as a result 

of OHV use. The season of use would be shortened on 1 mile of NFTS roads and motorized trails within 

1⁄4 mile of private land which would lessen the impact on the same private land owners. No ML 1 roads 

would be reopened. 

Amendments to Forest Plan: The Forest Plan Amendment would not have any impacts to adjacent 

land owners. 

Cumulative Effects: Alternative 2 would reduce the impacts within 1⁄4 mile of adjacent private land 

by lowering the amount of mileage available for wheeled motorized use from 1,454.3 miles to 876.6. It 

would also reduce the acreage of cross country use from 268,434.8 acres to 35.3 within 1⁄4 mile of private 

land. The cumulative effect would be a reduction in the impacts to adjacent land owners. 

Alternative 3 

Cross Country Travel: Cross country travel would be prohibited in Alternative 3. This would limit the 

proliferation of new unauthorized routes adjacent to private lands. The prohibition of cross country travel 

would also result in reducing use on all unauthorized roads, trails and areas not added to the NFTS. These 

changes would have a positive effect on adjacent land owners. 

Additions to the NFTS: There would be no additions of any roads trails or areas to the NFTS in 

Alternative 3. Since there would be no additions, there would be no potential adverse impacts on adjacent 

land owners from this element. 

Establishment of Motorized “Open Areas”: “Open Areas” would not be established within 1⁄4 mile 

of private land in Alternative 3. There would be no potential adverse impacts on adjacent private land 

owners from this element. 

Changes to the NFTS: There would be no changes to the NFTS in this alternative. 

Amendments to the Forest Plan: There would be no amendments to the Forest Plan in this 

alternative. 

Cumulative Effects: Alternative 3 would reduce the impacts within 1⁄4 mile of adjacent private land 

by lowering the amount of mileage available for wheeled motorized use from 1,454.3 miles to 858.2. It 

790 – Tahoe National Forest 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010 

Chapter 3: Affected Environment and Environmental Consequences – 3.10. Adjacent Ownerships 

would also reduce the acreage of cross country use from 268,434.8 acres to zero within 1⁄4 mile of private 

land. The cumulative effect would be a reduction in the impacts to adjacent land owners. 

Alternative 4 

Cross Country Travel: Cross country travel would be prohibited in Alternative 4. This would limit the 

proliferation of new unauthorized routes adjacent to private lands. The prohibition of cross country travel 

would also result in reducing use on all unauthorized roads, trails and areas not added to the NFTS. These 

changes would have a positive effect on adjacent land owners. 

Additions to the NFTS: Alternative 4 would add an additional 7.5 miles of motorized trails within 1⁄4 

mile of private land to the NFTS. These additional roads and motorized trails would have the potential to 

have adverse effects to the adjacent land owners. 

Establishment of Motorized “Open Areas”: “Open Areas” would not be established within 1⁄4 mile 

of private land in Alternative 4.There would be no potential adverse impacts on adjacent private land 

owners from this element. 

Changes to the NFTS: Alternative 4 would not approve mixed use on any NFTS within 1⁄4 mile of 

private land. It would however change the class of vehicle on 1.5 miles of NFTS within 1⁄4 mile of private 

land as a result of changed maintenance levels. This would result in additional noise and dust impacts as a 

result of OHV use. The season of use would be shortened on 376.5 miles of NFTS roads and motorized 

trails within 1⁄4 mile of private land which would lessen the impact on the same private land owners. No 

ML 1 roads would be reopened. 

Amendments to the Forest Plan: There would be no amendments to the Forest Plan in this 

alternative. 

Cumulative Effects: Alternative 4 would reduce the impacts within 1⁄4 mile of adjacent private land 

by lowering the amount of mileage available for wheeled motorized use from 1,454.3 miles to 867.1. It 

would also reduce the acreage of cross country use from 268,400 acres to zero within 1⁄4 mile of private 

land. The cumulative effect would be a reduction in the impacts to adjacent land owners. 

Alternative 5 

Cross Country Travel: Cross country travel would be prohibited in Alternative 5. This would limit the 

proliferation of new unauthorized routes adjacent to private lands. The prohibition of cross country travel 

would also result in reducing use on all unauthorized roads, trails and areas not added to the NFTS. These 

changes would have a positive effect on adjacent land owners. 

Additions to the NFTS: Alternative 5 would add an additional 21.3 miles of motorized trails within 

1⁄4 mile of private land to the NFTS. These additional roads and motorized trails would have the potential 

to have adverse effects to the adjacent land owners. 

Establishment of Motorized “Open Areas”: “Open Areas” would not be established within 1⁄4 mile 

of private land in Alternative 5. There would be no potential adverse impacts on adjacent private land 

owners from this element. 

Tahoe National Forest – 791 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010 

Chapter 3: Affected Environment and Environmental Consequences – 3.10. Adjacent Ownerships 

Changes to the NFTS: Alternative 5 would approve mixed use on 63.7 miles of NFTS roads within 

1⁄4 mile of private land. It would also change the class of vehicle on 38.6 miles of NFTS within 1⁄4 mile of 

private land as a result of changed maintenance levels. These changes in the class of vehicles would allow 

OHV use on these roads presently restricted to highway legal vehicles only. This would result in 

additional noise and dust impacts to adjacent land owners as a result of OHV use. 10.5 miles of ML 1 

roads would be reopened within 1⁄4 mile of private land. This would increase the amount of motor vehicle 

use near private land and would potentially have an adverse impact on the land owners. These adverse 

impacts would be mitigated by shortening the season of use on 394.4 miles of NFTS roads and motorized 

trails within 1⁄4 mile of private land. 

Amendments to the Forest Plan: The Forest Plan Amendment would not have any impacts to 

adjacent land owners. 

Cumulative Effects: Alternative 5 would reduce the impacts within 1⁄4 mile of adjacent private land 

by lowering the amount of mileage available for wheeled motorized use from 1,454.3 miles to 892.2. It 

would also reduce the acreage of cross country use from 268,434.8 acres to zero within 1⁄4 mile of private 

land. The cumulative effect would be a reduction in the impacts to adjacent land owners. 

Alternative 6 

Cross Country Travel: Cross country travel would be prohibited in Alternative 6. This would limit the 

proliferation of new unauthorized routes adjacent to private lands. The prohibition of cross country travel 

would also result in reducing use on all unauthorized roads, trails and areas not added to the NFTS. These 

changes would have a positive effect on adjacent land owners. 

Additions to the NFTS: Alternative 6 would add an additional 16.0 miles of motorized trails within 

1⁄4 mile of private land to the NFTS. These additional roads and motorized trails would have the potential 

to have adverse effects to the adjacent land owners. 

Establishment of Motorized “Open Areas”: One new area totaling 3.9 acres would be established 

as an “Open Area” within 1⁄4 mile of private land. This additional established “Open Area” would increase 

the potential for adverse effects to the adjacent land owners. 

Changes to the NFTS: Alternative 6 would approve mixed use on 4.1 miles of NFTS roads within 1⁄4 

mile of private land. It would also change the class of vehicle on 27.5 miles of NFTS within 1⁄4 mile of 

private land as a result of changed maintenance levels. These changes in the class of vehicles would allow 

OHV use on these roads presently restricted to highway legal vehicles only. This would result in 

additional noise and dust impacts to adjacent land owners as a result of OHV use. Only .4 miles of 

Maintenance Level 1 roads would be reopened within 1⁄4 mile of private land. This would increase the 

amount of motor vehicle use near private land and potentially have an adverse impact on the land owners. 

These adverse impacts would be mitigated by shortening the season of use on 387.5 miles of NFTS roads 

and motorized trails within 1⁄4 mile of private land. 

Amendments to the Forest Plan: The Forest Plan Amendment would not have any impacts to 

adjacent land owners. 

792 – Tahoe National Forest 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010 

Chapter 3: Affected Environment and Environmental Consequences – 3.10. Adjacent Ownerships 

Cumulative Effects: Alternative 6 would reduce the impacts within 1⁄4 mile of adjacent private land 

by lowering the amount of mileage available for wheeled motorized use from 1,454.3 miles to 879.7. It 

would also reduce the acreage of cross country use from 268,434.8 acres to 3.9 within 1⁄4 mile of private 

land. The cumulative effect would be a reduction in the impacts to adjacent land owners. 

Alternative 7 

Cross Country Travel: Cross country travel would be prohibited in Alternative 7. This would limit the 

proliferation of new unauthorized routes adjacent to private lands. The prohibition of cross country travel 

would also result in reducing use on all unauthorized roads, trails and areas not added to the NFTS. These 

changes would have a positive effect on adjacent land owners. 

Additions to the NFTS: Alternative 2 would add an additional 10.8 miles of motorized trails within 

1⁄4 mile of private land to the NFTS. These additional roads and motorized trails would have the potential 

to have adverse effects to the adjacent land owners. 

Establishment of Motorized “Open Areas”: “Open Areas” would not be established within 1⁄4 mile 

of private land in Alternative 7.There would be no potential adverse impacts on adjacent private land 

owners from this element. 

Changes to the NFTS: The only changes to the NFTS within 1⁄4 mile of private land in Alternative 7 

would be changing the class of vehicle on 1.5 miles of NFTS as a result of changed maintenance levels. 

This change in the class of vehicles would allow OHV use on these roads presently restricted to highway 

legal vehicles only. This would result in additional noise and dust impacts to adjacent land owners as a 

result of OHV use. 

Amendments to the Forest Plan: There would be no amendments to the Forest Plan in this 

alternative. 

Cumulative Effects: Alternative 7 would reduce the impacts within 1⁄4 mile of adjacent private land 

by lowering the amount of mileage available for wheeled motorized use from 1,454.3 miles to 869. It 

would also reduce the acreage of cross country use from 268,400 acres to zero within 1⁄4 mile of private 

land. The cumulative effect would be a reduction in the impacts to adjacent land owners. 

Tahoe National Forest – 793 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010 

Chapter 3: Affected Environment and Environmental Consequences – 3.10. Adjacent Ownerships Table 3.10-4. Miles of roads and trails for each alternative within 1⁄4 mile of private land by class of vehicle and season of use 

Action type Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 

1. Cross country travel (miles) (acres) 

596.2 

268,400 

0 0 

0 0 

0 0 

0 0 

2. Additions to the NFTS 

a. Roads added to the NFTS 0.0 0.0 0.0 0.0 0.0 

b. Motorized Trails added to the NFTS 0 16.3 0.0 7.5 21.3 

3. Establishment of Motorized “Open Areas” (acres) 0 35.3 0 0 0 

4. Changes to the NFTS 

a. Change in Class of Vehicles resulting from approval of mixed use 

0 63.7 0.0 0.0 63.7 

b. Change in Class of Vehicles resulting from changes in maintenance levels 

0 38.6 0.0 1.5 38.6 

c. Change in Season of Use 0 1.0 0.0 376.5 394.4 

d. Reopening Maintenance Level 1 Roads 0 0.0 0.0 0.0 10.5 

5. Amendments to the Forest Plan No Effect 

Total Miles* 

Total Acres 

1454.3 

268,434.8 

876.6 

35.3 

858.2 

0 

867.1 

0 

892.2 

0 

*Includes State, County and private roads. Alternative 1 also includes unauthorized routes and closed NFTS roads still receiving some motorized use. 794 – Tahoe National Forest 
 

 

 

Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010 

Chapter 3: Affected Environment and Environmental Consequences – 3.10. Adjacent Ownerships 

Summary of Effects Analysis across All Alternatives 

The following table summarizes the effects analysis for adjacent ownerships by ranking each alternative 

regarding how well it provides for each of the indicators. The following rankings were used: A score of 7 

indicates the alternative has the least impact for adjacent ownerships related to the indicator. A score of 1 

indicates the alternative has the greatest adverse impact for adjacent ownerships. 

Table 3.10-5. Comparison of Effects to Adjacent Ownerships 

Indicator Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7 

Number of additions to the NFTS and 

reopening of Maintenance Level 1 Roads 

crossing private requiring prior approval from 

the private land owner 

1 3 7 6 2 5 4 

Management of wheeled motorized activities 

within 1⁄4 mile of private land. 

1 4 7 6 2 3 5 

Average 1 3.5 7 6 2 4 4.5 

Tahoe National Forest – 795 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010 

Chapter 3: Affected Environment and Environmental Consequences – 3.10. Adjacent Ownerships 

796 – Tahoe National Forest 
Chapter 3.11 

Society, Culture 

& Economy 

Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Tahoe National Forest – 797

3.11. Society, Culture & Economy __________________________

The Tahoe National Forest Region (TNF Region) encompasses more area than the TNF itself. For the 

purposes of this EIS, the TNF Region consists of all or part of Five California counties. These counties 

are Nevada, Placer, Plumas, Yuba and Sierra. Information on TNF Region’s society, culture, and 

economy is organized using these five counties.

In the western portion of the TNF Region, people orient themselves to the Sacramento area for work 

and to the TNF for recreation activities. In the eastern portion of the TNF Region, residents focus on 

Reno, Sparks, and Carson City in Nevada for work and the nearby Tahoe National Forest for recreation.

Population and Demographics

Historical Background

People have lived in the TNF Region for thousands of years. Americans of European ancestry came to the 

TNF Region during the latter half of the nineteenth century. They introduced a different culture and 

outlook toward the Forest. The area attracted settlers who transformed the foothills with European 

agricultural practices and intense, but localized, resource extraction. Gold discovery in 1848 brought 

thousands of miners to the TNF Region. When gold supplies diminished, many people left the region.

Economic activity shifted to extensive renewable resource extraction, principally timber, and agriculture.

People in the TNF Region today derive their livelihood and well-being in diverse ways. The Forest is 

used for traditional cultural subsistence, scientific and educational exploration, logging, mining, and 

recreating on the weekends, and telecommuting from a home in the woods during the work week. People 

in the TNF Region are as diverse as their activities and their reasons for living in the region.

Current Population and Growth Trends

The Sierra Nevada Region counties contain an estimated 400,000 people (Table 3.11-1). The population 

of the Sierra Nevada Region is changing in terms of numbers of people, age and ethnic composition, 

incomes, occupations, and leisure activities.

Table 3.11-1. Historic Population of Counties in the TNF Region (thousands of people)

County 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 Percent 

change,1989-1999

Plumas 19.3 19.7 19.9 20.2 20.6 20.6 20.5 20.4 20.4 20.6 20.5 6.0

Sierra 3.2 3.3 3.3 3.3 3.3 3.4 3.4 3.4 3.4 3.4 3.2 -0.4

Nevada 74.1 78.5 80.4 82.2 83.6 84.9 85.9 86.8 87.7 88.8 89.6 21.0

Placer 161.0 172.8 178.4 184.1 189.4 194.1 199.6 206.3 212.4 217.9 225.9 40.3

Yuba 56.3 58.8 59.5 60.6 61.4 61.8 62.1 61.4 60.8 61.4 60.4 7.3

Total 313.9 341.5 350.5 358.3 364.7 371.5 378.3 384.7 392.1 399.6 399.6 27.3

City/County Population and Housing Estimates, 1990-1999. Sacramento, CA: State of California, Department of Finance

Approximately 57 percent of the TNF Region’s population lives in Placer County. Placer County has 

also seen the largest population growth in recent years with more than a 40 percent increase. The smallest 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

798 – Tahoe National Forest

proportion of the TNF Region’s population lives in Sierra County with less than one percent of the 

population. The population of Sierra County has actually been declining in recent years.

California State agencies have projected population growth for the TNF Region’s counties. In the next 

decade, most counties are expected to grow at a faster rate than they did between 1989 and 1998.

Population increases may affect how communities develop.

Ethnicity

The distribution of ethnic groups in the Sierra Nevada Region differs significantly from the State of 

California averages. The White, not Hispanic population in the TNF Region ranges from 69.7 to 93.2 

percent compared to the State average of 51.5 percent. See Table 3.11-2. Yuba County has a Hispanic 

population of 13.3 percent, the other counties range from 4.9 to 8.7 percent compared to the State average 

of 29.9 percent. Yuba County matches the State average of Asian/Pacific Islander population of 11.1 

percent while the other counties range .3 to 2.5 percent. The State average of Black Americans is 6.9 

percent compared to the TNF Region’s range of .2 percent to 3.8 percent. The population of American 

Indians in the TNF Region is greater than the State Average ranging .8 to 3.0 percent compared to .6 for 

the State.

Table 3.11-2. Percent of TNF Region county populations by ethnicity, 1998

County White, not 

Hispanic

(percent)

Hispanic

(percent)

Asian/ Pacific 

Islander (percent)

Black 

American

(percent)

American 

Indian

(percent)

Plumas 89.9 5.7 0.6 0.8 3.0

Sierra 92.0 5.8 0.3 0.2 1.8

Nevada 93.2 4.9 0.8 0.2 0.9

Placer 87.3 8.7 2.5 0.7 0.8

Yuba 69.7 13.3 11.1 3.8 2.1

State Average 51.5 29.9 11.1 6.9 0.6

As the population of the Sierra Nevada Region grows, the ethnic composition of its residents will 

change. The population of the TNF Region is expected to more than double over the next 50 years. At the 

same time, the number of Hispanic residents is projected to grow at a greater rate than the number of 

white residents. Proportions of other ethnic groups, except whites, are expected to remain essentially the 

same as in 1998 (Sierra Nevada Forest Plan Amendment FEIS 2001). See Table 3.11-3
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Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

Tahoe National Forest – 799

Table 3.11-3. Projected populations of the TNF Region counties by ethnicity, 2040

County White, not 

Hispanic

(percent)

Hispanic

(percent)

Asian/Pacific 

Islander

(percent)

Black 

American

(percent)

American 

Indian

(percent)

Total 

Population

(thousands)

Plumas 79.0 15.6 0.7 0.7 4.0 24.6

Sierra 90.3 8.5 0.2 0.1 0.9 3.5

Nevada 94.1 4.9 0.5 0.8 0.6 249.3

Placer 80.4 13.5 4.3 0.8 0.9 522.2

Yuba 45.4 22.0 28.2 3.0 1.4 109.8

State Average 44.4 34.9 13.3 6.4 0.6

Total 909.4

Age Distribution of the Population

The largest percentages of elderly people (more than 65 years old) live in Plumas, Sierra and Nevada 

Counties. The largest percentages of young people (17 years old or younger) live in Placer and Yuba 

Counties as shown in Table 3.11-4 below (Sierra Nevada Forest Plan Amendment FEIS 2001).

Table 3.11-4. Percent of Population of TNF Region counties by age group, 1998

County Age Groups

0-4 5-17 18-30 31-45 46-65 >65

Plumas 4.4 17.0 15.6 19.2 24.5 19.4

Sierra 3.0 17.6 14.3 19.5 26.7 19.0

Nevada 4.9 17.0 14.4 19.8 24.9 19.0

Placer 6.9 19.5 15.3 23.4 23.4 11.0

Yuba 9.1 24.5 17.5 22.5 16.6 9.8

Projections for 2010 indicate that absolute numbers of elderly people will rise, but the proportion of 

elderly people will remain constant or drop in all Counties. At the same time, the share of the population 

less than 17 years old is also projected to drop.

Table 3.11-5 shows that by 2040, the share of the population that is less than 17 years old will have 

increased. Elderly people will be a lower percentage of the population than they are currently. High birth 

rates and in-migration is expected to double populations between 1998 and 2040 in Placer County.

Table 3.11-5. Projected percent of population of TNF Region Counties by age group, 2040

County 0-4 5-17 18-30 31-45 46-65 >65 Percent Population Growth 

1998-2040

Plumas 5.5 13.5 15.2 17.4 27.6 20.8 19.4

Sierra 4.3 10.6 13.4 15.7 31.3 24.7 2.1

Nevada 5.8 14.9 15.3 17.9 24.9 21.2 82.3

Placer 6.8 17.6 16.7 18.7 22.5 17.7 132.6

Yuba 9.3 21.7 19.2 17.4 18.9 13.4 76.7
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800 – Tahoe National Forest

Per Capita Income

Table 3.11-6 shows historical per capita incomes for residents of the Sierra Nevada Region, with 

adjustment for inflation, for the period 1972 to 1997 (Sierra Nevada Forest Plan Amendment FEIS 2001).

In 1972, the Counties with the three highest per capita incomes were Sierra and Placer. The lowest 

income was in Yuba County. All Counties, however, have shown net gains for real income over the 

period, but the rate of gains has differed markedly. Incomes have grown fastest in Plumas and Nevada 

Counties over the last 25 years. Slowest income growth has been in Yuba County.

Table 3.11-6. Inflation-adjusted per capita incomes - Residents of TNF Region counties, 1972-1997

County Thousands of 1995 Dollars

1972 1977 1982 1987 1994 1997 Percent Change

1972-1997

Plumas 15.1 16.1 15.4 18.2 19.3 21.2 40.5%

Sierra 15.7 15.9 14.7 18.2 18.5 19.8 26.5%

Nevada 14.9 16.9 15.9 19.6 20.8 21.8 46.0%

Placer 15.5 18.5 19.4 23.9 25.2 27.9 79.5%

Yuba 12.5 13.4 13.3 14.4 14.7 15.1 20.4%

Employment and Income: Affected Environment

Labor Force Trends

During the 1990s, the TNF Region experienced different trends in labor force development. The Gold 

Country and Carson Range subregions had the greatest growth in labor force, with a 15 percent increase 

in nine years. This growth occurred despite a statewide recession in California. These two subregions 

share parts of the Interstate 80 corridor, and lie in or near the Sacramento and Reno metropolitan areas.

Trends in workforce numbers have been negative in counties where the timber industry, ranching, or 

both have historically played a significant economic role. Of all counties in the Sierra Nevada Region, 

Sierra County has experienced the greatest reduction in workforce, down by 19 percent between 1990 and 

1998.

Unemployment

In most Sierra Nevada counties and communities, unemployment rates between 1990 and 1998 were 

higher than average statewide unemployment rates. Exceptions to this trend were foothill communities in 

Nevada, and Placer counties (all of which are within commuting distance of Sacramento).

Unemployment data aggregated by county or by subregion do not show differences in unemployment 

between communities. In general, more remote communities at high elevations have higher 

unemployment rates than lower elevation communities in the same county.

Seasonal Employment

Many jobs related to recreation are seasonal. Rural residents often take several part-time jobs during a 

year. Peak employment months in the summer indicate the importance of summer recreational 
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Tahoe National Forest – 801

employment. For most counties in the TNF Region, January and February are the lowest employment 

months of the year.

The ratio of employment in the lowest employment month to the highest employment month is an 

index of the relative magnitude of employment swings in a county. A ratio close to 1 indicates 

comparatively smaller fluctuations in employment than lower ratios. Table 3.11-7 provides information 

about the seasonality of employment in the counties in TNF Region. Nevada and Placer Counties

experience slight changes in total employment over the course of a year. Plumas and Sierra Counties, 

where recreation and tourism are important to county economies, have the lowest ratios, and therefore the 

greatest swings in employment during a year.

Table 3.11-7 displays trends in the share of temporary jobs among all jobs between the period from 

1989 through 1993 and the period from 1994 through 1998. A negative value in the change in share of 

employment indicates a relative increase in seasonal jobs between the two periods, and a positive value a 

decrease in the proportion of seasonal jobs. Sierra County, which lost the largest proportion of workforce 

in the 1990s, shows the highest change toward more permanent jobs. This trend may indicate that the jobs 

lost in Sierra County were seasonal jobs.

Table 3.11-7. Patterns and Trends in Seasonality of Employment in TNF Region Counties, 1989-1998

County Average Lowest 

Employment

Month, 1994-1998

Average Peak 

Employment

Month, 1994-1998

Ratio Peak Month 

Employment to Low Month 

Employment, 1994-1998

Change in Share of 

Permanent Employment, 

1989-1993 vs. 1994-1998

Plumas January September 0.80 +2.8

Sierra January August 0.82 +11.3

Nevada April August 0.96 -8.4

Placer January November 0.97 -15.7

Yuba February August 0.86 +4.8

Total - All 

California

January August 0.96 -4.1

Sources: State of California Employment Development Department, Labor Market Information Division

Employment and Income: Environmental Consequences

Economic Impacts

The assessment of economic impacts attempts to identify potential effects that Forest Service 

management may have on local, county, and regional economic systems and on people using the natural 

resources that the TNF provides. In particular, would changes in the use of the National Forest for 

recreation and the amount of change in the designation of forest roads and trails be large enough or 

significant enough to cause measurable economic changes? Is the economy of the local area diverse 

enough and robust enough that the proposed changes would be insignificant or would they be felt in very 

specific segments of the local economy?
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Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

802 – Tahoe National Forest

National Visitor Use Monitoring (NVUM)

The National Visitor Use Monitoring (NVUM) program provides reliable information about recreation 

visitors to National Forest System managed lands at the National, Regional, and Forest level. Information 

about the quantity and quality of recreation visits is required for LRMPs, Executive Order 12862 (Setting 

Customer Service Standards), and implementation of the National Recreation Agenda. To improve public 

service, the agency’s Strategic and Annual Performance Plans require measuring trends in user 

satisfaction and use levels. NVUM information assists Congress, Forest Service leaders, and program 

managers in making sound decisions that best serve the public and protect valuable natural resources by 

providing science based, reliable information about the type, quantity, quality and location of recreation 

use on public lands. The information collected is also important to external customers including state 

agencies and private industry. NVUM methodology and analysis is explained in detail in the research 

paper entitled Forest Service National Visitor Use Monitoring Process: Research Method Documentation

(2002). (www.fs.fed.us/recreation/programs/nvum).

The TNF participated in the NVUM project from October 2004 through September 2005. There were 

approximately 3,930,000 TNF visits during fiscal year 2005. The full TNF NVUM report is available on 

the web through the Natural Resource Information System (NRIS) Human Dimensions Module. 

Table 3.11-8 presents participation rates by activity for the Tahoe National Forest during the NVUM 

survey period. The “Total Activity Participation (%)” column of the table presents the participation rates 

by activity. Participation rates will exceed 100% since visitors can participate in multiple activities. The 

“Percent as Main Activity” column presents the participation rates in terms of primary activity.

http://fsweb.nris.fs.fed.us/products/Human_Dimensions_NVUM/HD-NVUM_12/index.shtml

Table 3.11-8. Activity Participation on Tahoe National Forest (NVUM FY2005 data)

Activity Activity Emphasis for 

Road & Trail Use

Total Activity 

Participation (%)

Percent as Main 

Activity (%)

Snowmobiling Motorized 7.6 7.2

Driving for Pleasure Motorized 15.9 3.0

OHV Use Motorized 3.9 1.6

Other Motorized Activity Motorized 3.3 1.6

Motorized Subtotal 13.4

Hiking / Walking Non-motorized 32.4 15.7

Bicycling Non-motorized 7.7 6.2

Other Non-motorized Non-motorized 11.1 4.2

Cross country Skiing Non-motorized 5.0 3.7

Backpacking Non-motorized 0.7 0.4

Horseback Riding Non-motorized 0.2 0.1

Non-motorized Subtotal 20.5
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Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

Tahoe National Forest – 803

Activity Activity Emphasis for 

Road & Trail Use

Total Activity 

Participation (%)

Percent as Main 

Activity (%)

Downhill Skiing Other 32.4 31.5

Fishing Other 15.3 11.5

Viewing Natural Features Other 53.6 6.0

Relaxing Other 36.6 3.6

Motorized Water Activities Other 6.2 2.0

Hunting Other 2.2 1.6

Non-motorized Water Other 3.1 1.7

Developed Camping Other 5.6 1.2

Primitive Camping Other 1.6 0.6

Picnicking Other 9.3 0.6

Viewing Wildlife Other 36.3 0.3

Sightseeing Other 0.0 0.0

No Activity Reported Other 2.5 2.5

Resort Use Other 1.6 0.2

Visiting Historic Sites Other 4.9 0.2

Nature Study Other 3.7 0.1

Gathering Forest Products Other 1.5 0.1

Nature Center Activities Other 1.9 0.0

Other Subtotal 63.7

Total 104.5

The primary activity participation rates obtained from the NVUM 2005-2005 (Percent as Main 

Activity) displayed in Table 3.11-8 were used to estimate use by activity emphasis. The emphasis areas 

were grouped into those emphasizing non-motorized, motorized and other activities. Motorized activities 

were those that used motor vehicles on Forest Service roads and trails. Non-motorized activities still used 

the Forest’s roads and trails, but on foot or by non-motorized transportation such as cross country skis or 

bicycles. All other activities are all the other Forest based activities measured by the NVUM survey that 

didn’t utilize roads or trails to pursue their primary activity. Examples of “other” are downhill skiing, 

motorized water activities, etc. Motor vehicles may have been used to reach a destination or participate in 

the activity, but it was not the primary emphasis of the visit.

Table 3.11-8a displays the number of visits for these activities. The number of visits is based on the 

primary purpose for the visit (Percent as Main Activity) and the total number of visits of 3,931,709 

reported in the TNF NVUM report. Users were determined to be either local or non-local based on the 

miles from the user’s residence to the Forest boundary. If the user reported living within 50 miles of the 

Forest boundary, they are considered local; if over 50 miles, they are considered non-local. It is critically 

important to distinguish between local and non-local spending as only non-locals bring new money and 

new economic stimulus into the local community. Local spending is already accounted for in the study 

area base data. It is impossible to predict how locals would have spent money if they didn’t have local 

recreation opportunities on the National Forest, but it’s a safe guess that much of that money would not 

have been lost to the local economy. People tend to substitute other local recreation activities or change 

the time or place for continuing the same activity rather than traveling long distances and incurring high 
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Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

804 – Tahoe National Forest

costs to do the same activity. Table 3.11-8a indicates that the most popular non-motorized use is 

hiking/walking, followed by bicycling. The most popular motorized use is snowmobiling, followed by

driving for pleasure. Table 3.11-9 indicates that non-local visitors spend more per visit than local visitors 

primarily because of overnight lodging expenditures. Motorized day use expenditures are generally higher 

than for non-motorized activities, but non-local overnight visitors engaged in non-motorized activities 

generally expend more than non-local motorized users (except for snowmobiling). Snowmobilers spend 

the most per visit, especially non-local visitors.

Table 3.11-8a. Number of Party Trips by Activity

Use (Party Trips)

Non-local Day 

Use

Non-local 

Overnight

Local Day 

use

Local 

Overnight

Non-Primary

Non-motorized

Hiking/Walking 9,975 19,650 91,650 7,142 5,819

Bicycling 9,939 7,643 36,193 2,820 2,298

Other Non-motorized 2,669 5,178 24,518 1,910 1,557

Cross country Skiing 2,204 6,832 14,489 1,073 247

Backpacking 0 1,206 0 1,309 58

Horseback Riding 64 123 584 45 37

Motorized

Snowmobiling 3,821 6,245 29,761 5,575 5,004

Driving for Pleasure 1,430 1,732 19,737 682 2,293

OHV Use 1,398 2,455 6,405 1,868 411

Other Motorized Activity 1,398 2,455 6,405 1,868 411
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Tahoe National Forest – 805

Use (Party Trips)

Non-local Day 

Use

Non-local 

Overnight

Local Day 

use

Local 

Overnight

Non-Primary

Other

Fishing 10,549 20,015 45,668 8,439 3,653

Hunting 635 2,809 7,849 3,090 400

Viewing Wildlife 200 463 841 146 297

Motorized Water Activities 1,747 3,069 8,006 2,335 513

Non-motorized Water 1,080 2,096 9,924 773 630

Downhill Skiing 17,513 41,280 105,076 33,624 9,058

Developed Camping 667 1,573 4,003 1,281 345

Primitive Camping 0 1,809 0 1,963 87

Resort Use 111 262 667 213 58

Picnicking 334 786 2,001 640 173

Viewing Natural Features 4,003 9,226 16,812 2,919 5,930

Visiting Historic Sites 111 262 667 213 58

Nature Center Activities 0 0 0 0 0

Nature Study 67 154 280 49 99

Relaxing 2,001 4,718 12,009 3,843 1,035

Gathering Forest Products 56 131 334 107 29

Sightseeing 0 0 0 0 0

No Activity Reported 1,390 3,276 8,339 2,669 719

Subtotal 59,710 140,745 358,260 114,643 30.643

Table 3.11-9. Expenditures ($ per visit) by Activity

Expenditures ($ per visit)

Non-local 

Day Use

Non-local 

Overnight

Local Day 

use

Local 

Overnight

Non-Primary

Non-motorized

Hiking/Walking 17.62 106.96 11.11 39.55 7.41

Bicycling 17.62 106.96 11.11 39.55 7.41

Other Non-motorized 17.62 106.96 11.11 39.55 7.41

Cross country Skiing 18.93 119.64 14.78 87.39 13.60

Backpacking 0.00 19.09 0.00 24.10 0.00

Horseback Riding 17.62 106.96 11.11 39.55 7.41

Motorized

Snowmobiling 49.09 128.80 29.57 68.93 28.33

Driving for Pleasure 17.62 66.54 13.33 42.73 10.00

OHV Use 28.57 64.80 19.00 48.50 14.62

Other Motorized Activity 28.57 64.80 19.00 48.50 14.62
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806 – Tahoe National Forest

Expenditures ($ per visit)

Non-local 

Day Use

Non-local 

Overnight

Local Day 

use

Local 

Overnight

Non-Primary

Other

Fishing 21.00 95.65 20.00 48.00 20.00

Hunting 38.10 116.32 30.00 79.47 25.50

Viewing Wildlife 20.80 82.59 10.80 53.75 10.00

Motorized Water Activities 18.52 70.36 15.00 49.20 12.41

Non-motorized Water 18.52 70.36 15.00 49.20 12.41

Downhill Skiing 36.36 117.93 25.24 89.13 27.89

Developed Camping 0.00 50.36 0.00 41.29 0.00

Primitive Camping 0.00 19.09 0.00 24.10 0.00

Resort Use 18.52 70.36 15.00 49.20 12.41

Picnicking 18.52 70.36 15.00 49.20 12.41

Viewing Natural Features 18.52 70.36 15.00 49.20 12.41

Visiting Historic Sites 18.52 70.36 15.00 49.20 12.41

Nature Center Activities 18.52 70.36 15.00 49.20 12.41

Nature Study 18.52 70.36 15.00 49.20 12.41

Relaxing 18.52 70.36 15.00 49.20 12.41

Gathering Forest Products 18.52 70.36 15.00 49.20 12.41

Sightseeing 18.52 70.36 15.00 49.20 12.41

No Activity Reported 18.52 70.36 15.00 49.20 12.41

Economic Effects

The employment and labor income effects stemming from current motorized and non-motorized activities 

occurring on the TNF were estimated. The economic effects of all other types of recreation combined on 

the TNF have also been reported for comparison purposes. Economic effects tied to motorized and nonmotorized activities were estimated to address the economic impact issue tied directly to Travel 

Management. Also, the marginal economic effects (employment and labor income effects per 1,000 

visits) of motorized and non-motorized use are provided. The marginal effects (also called “response 

coefficients”) are useful for performing sensitivity analyses of various management alternatives.

Economic Effects Analysis Procedures

Economic effects can be categorized as direct, indirect and induced. Direct effects are changes directly 

associated with spending by a recreation visitor. Indirect and induced effects are the multiplier effects 

resulting from subsequent rounds of spending in the local economy.

Input-output analysis was used to estimate the direct, indirect and induced employment and labor 

income effects stemming from motorized and non-motorized use. Input-output analysis (Hewings 1985) 

is a means of examining relationships within an economy both between businesses as well as between 

businesses and final consumers. It captures all monetary market transactions for consumption in a given 
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Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

Tahoe National Forest – 807

time period. The resulting mathematical representation allows one to examine the effect of a change in 

one or several economic activities on an entire economy. This examination is called impact analysis. 

Input-output analysis requires the identification of an economic impact area. The economic area, used for 

this jobs and income analysis, was five counties in Northern California and one in Nevada surrounding 

the TNF. The counties included in California are Nevada, Placer, Plumas, Sierra and Yuba, and Washoe 

County, Nevada.

The IMPLAN Pro input-output modeling system and 2006 IMPLAN data (the most recent data 

available) were used to develop the input-output model for this analysis (IMPLAN Professional 2004). 

IMPLAN translates changes in final demand for goods and services into resulting changes in economic 

effects, such as labor income and employment of the affected area’s economy. For the economic impact 

area, employment and labor income estimates that were attributable to all current recreation use (wildlife 

and non-wildlife activities), motorized, non-motorized and other activities for the TNF were generated.

The expenditure and use information collected by the NVUM survey are crucial elements in the 

economic analysis. As reported earlier, the NVUM survey collects use and expenditure information for 

various activity types. The expenditure information is collected by twelve activity groups within four trip 

segments (non-local overnight trips, non-local day trips, local day trips and local overnight trips) (Stynes 

and White 2005; Stynes and White 2006). The reported spending for each of the spending categories is 

allocated to the appropriate industry within the IMPLAN model (the allocation process, also referred to as 

“bridging,” was conducted by the USDA Forest Service, Planning Analysis Group in Fort Collins, CO). 

The bridged IMPLAN files were used to estimate economic effects (e.g., employment and labor income) 

related to changes in spending (i.e., changes in spending – technically referred to as changes in final 

demand - are caused by changes in use).

Estimated Economic Effects

Estimated economic effects (full and part-time jobs and labor income) are displayed in the following 

ways:

1. Direct, and indirect and induced employment and labor income response coefficients by activity 

type (jobs and labor income per 1,000 visits); and

2. Estimated employment and labor income by motorized and non-motorized activity types.

Response Coefficients by Activity Type

Table 3.11-10 displays the estimated employment and labor income response coefficients (employment 

and labor income per 1,000 visits) by local and non-local activity types. The response coefficients 

indicate the number of full and part-time jobs and dollars of labor income per thousand visits by activity 

type. The response coefficients are useful in: 1) understanding the economic effects tied to a given use 

level; 2) understanding projected employment effects for various use scenarios (sensitivity analysis); and 

3) understanding the differences in employment effects by activity type. The response coefficients 

displayed in Table 3.11-10 along with the number of visits were used to estimate the economic effects for 

local and non-local use by activity type.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

808 – Tahoe National Forest

Analysis of information displayed in Table 3.11-10 indicates that economic effects tied to local 

visitation generate lower employment and labor income effects. This is a result of local visitors spending 

less per visit in comparison to non-local visitors (see Table 3.11-9). In addition, economic effects vary 

widely by motorized and non-motorized activity types. The lowest employment effect is tied to local 

hiking/walking, bicycling, other non-motorized and horseback riding activities (Note: the economic 

effects are identical for these categories since they share the same spending profile). The largest economic 

effect is associated with non-local cross country skiing, but is followed fairly closely by non-local 

snowmobiling. In general, economic effects vary by the amount of spending and by the type of activity, 

but it cannot be generalized that motorized or non-motorized activities contribute more or less to the local 

economy on a per visit basis. It is also important to be careful with the use of response coefficients. They 

reflect an economic structure that is a snapshot in time, that is, they are not applicable to visitation 

numbers that are dramatically different from current recreation levels. If recreation activities and/or visits 

were to change radically, there would be a structural shift in the economy as spending patterns changed 

and these response coefficients would no longer reflect underlying economic processes.

Table 3.11-10. Employment and Labor Income Response Coefficients by Activity Type

Employment

(Jobs per 1,000 Party-Trips)

Labor Income (2006 dollars)

($ per 1,000 Party-Trips)

Direct 

Effects

Indirect & Induced 

Effects

Direct 

Effects

Indirect & 

Induced Effects

Non-motorized Use

Hiking/ Walking, 

Bicycling, Horseback 

Riding, Other Nonmotorized

Local Day 0 0 $4,497 $2,832

Local Overnight 1 0 $20,858 $13,610

Non-Local Day 0 0 $9,840 $5,375

Non-Local Overnight 2 1 $65,265 $40,393

NP 0 0 $4,497 $2,832

Backpacking Local Day 0 0 $0 $0

Local Overnight 1 0 $18,864 $14,050

Non-Local Day 0 0 $0 $0

Non-Local Overnight 1 0 $25,717 $15,671

NP 1 0 $19,864 $14,050
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Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

Tahoe National Forest – 809

Employment

(Jobs per 1,000 Party-Trips)

Labor Income (2006 dollars)

($ per 1,000 Party-Trips)

Direct 

Effects

Indirect & Induced 

Effects

Direct 

Effects

Indirect & 

Induced Effects

Motorized Use

OHV Use Local Day 0 0 $7,971 $5,133

Local Overnight 1 0 $21,248 $14,331

Non-Local Day 0 0 $12,531 $8,069

Non-Local Overnight 1 1 $35,416 $23,885

NP 0 0 $7,971 $5,133

Driving Local Day 0 0 $4,960 $3,036

Local Overnight 1 0 $27,264 $16,878

Non-Local Day 0 0 $7,801 $4,774

Non-Local Overnight 2 1 $45,447 $28,134

NP 0 0 $4,960 $3,036

Snowmobile Local Day 1 0 $14,256 $9,080

Local Overnight 2 1 $50,348 $31,460

Non-Local Day 1 0 $24,227 $14,834

Non-Local Overnight 3 1 83,919 $52,436

NP 1 0 $14,256 $9,080

Cross Country Ski Local Day 0 0 $8,287 $5,318

Local Overnight 2 1 $54,525 $34,350

Non-Local Day 1 0 $13,018 $8,354

Non-Local Overnight 4 1 $90,881 $57,253

NP 0 0 $8,287 $5,318

All Other Use

All Other Activities

Local Day 0 0 $8,647 $4,845

Local Overnight 1 0 $34,829 $18,284

Non-Local Day 0 0 $14,606 $7,711

Non-Local Overnight 2 1 $67,234 $32,411

NP 0 0 $8,647 $4,845

All Other Activities includes Developed Camping, Primitive Camping, Resort Use, Picnicking, Viewing Natural Features, Visiting 

Historic Sites, Nature Center Activities, Nature Study, Relaxing, Fishing, Hunting, Motorized Water Activities, Non-motorized Water, 

Downhill Skiing, Gathering Forest Products, Viewing Wildlife, Sightseeing, and No Activity Reported.

Motorized and Non-motorized Use

Table 3.11-11 displays the estimated employment and labor income effects for current use levels reported 

by NVUM for local and non-local non-motorized and motorized activities. Table 3.11-12 expresses these 

employment and labor income effects as a percent of total employment and income for each activity. In 

general, the estimated economic effects are a function of the number of visits and the dollars spent locally 

by the visitors. For example, non-local users typically spend more money per visit than local users. Also, 

activities that draw more users will be responsible for more economic activity in comparison to activities 

that draw fewer users, holding constant spending per visit. Given that the analysis is dependent on 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

810 – Tahoe National Forest

visitation and expenditure estimates, any changes to these estimates affect the estimated jobs and labor 

income.

Table 3.11-11 indicates that approximately 217 total average annual jobs in the 5 county area (direct, 

indirect and induced, full-time, temporary, and part-time) and $6.9 million total labor income (direct, 

indirect and induced) are attributable to non-motorized visitation on the TNF. The two largest activities 

are hiking/walking and cross country skiing. Together these activities account for about 12% of the jobs 

and 11% of the income generated from all of the activities analyzed. These activities account for about 

147 jobs and provided $4.6 million in labor income to the 5 county area.

Motorized activities were responsible for approximately 103 total jobs (direct, indirect and induced) 

and $3.2 million total labor income (direct, indirect and induced). The two largest motorized uses are 

snowmobiling and driving for pleasure. These two activities contribute about 6.4% of the jobs from the 

activities in the table, and provide about 5.7% of the labor income. Together these two activities 

contribute 84 jobs and provide about $2.6 million in labor income to the 5 county area.

“All Other Activities” (see Table 3.11-8 for a list) are significant economic contributors for the 

activities studied. They provide 952 jobs, or 75% of the jobs from the activities analyzed. Labor income is 

about $34 million, or 77% of the income generated by these activities.

Table 3.11-12 shows that about 17% of the jobs provided from these activities are from nonmotorized use, 8% from motorized use and 75% from “Other Activities.” The contributions to labor 

income are 16% non-motorized use, 7% motorized use and 77% from “Other Activities.”

Table 3.11-11. Employment and Labor Income Effects by Activity Type

Employment

(full & part-time jobs)

Labor Income

(2008 dollars)

Direct Indirect & Induced Direct Indirect & Induced

Non-Motorized Use

Backpacking - Local 1 0 $26,909 $19,033

Non-local 1 0 $32,105 $19,564

Hiking/Walking - Local 21 9 $581,556 $369,257

Non-local 52 20 $1,409,203 $864,779

Horseback Riding - Local 0 0 3,704 $2,352

Non-local 0 0 $8,976 $5,508

Bicycling - Local 8 3 $229,659 $145,821

Non-local 20 8 $556,500 $341,505

Cross country Skiing - Local 7 3 $184,869 $117,924

Non-local 25 10 $672,460 $423,983

Other Non-motorized - Local 6 2 $155,575 $98,782

Non-local 14 5 $376,984 $231,342

Total Non-motorized 155 61 $4,238,500 $2,639,849

Subtotal 217 $6,878,349
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

Tahoe National Forest – 811

Employment

(full & part-time jobs)

Labor Income

(2008 dollars)

Direct Indirect & Induced Direct Indirect & Induced

Motorized Use

OHV Use - Local 3 1 $93.937 $61,744

Non-local 4 2 $108,139 $72,378

Driving for Pleasure - Local 5 2 $120,601 $73,949

Non-local 4 1 $93,027 $57,508

Snowmobiling - Local 27 11 $729,783 $461,315

Non-local 25 9 $638,280 $397,622

Other Motorized Activity - Local 3 1 $93,937 $61,744

Non-local 4 2 108,139 $72,378

Total Motorized 74 29 $1,985,843 $1,258,638

Subtotal 103 $3,244,481

All Other Use

All Other Activities - Local 254 118 $8,762,334 $4,884,906

Non-local 403 176 $13,557,831 $6,960,639

Total Other 658 295 $22,320,165 $11,845,545

Subtotal 952 $34,165,710

Grand Total 887 385 $28,544,508 $15,744,032

Table 3.11-12. Percent of Total Employment and Labor Income Effects by Activity Type

Employment

(% of full & part-time jobs)

Labor Income (2008 dollars)

(% of Total Income)

Direct Indirect & 

Induced

Direct Indirect & 

Induced

Non-Motorized Use

Backpacking - Local 0.1% 0.0% 0.1% 0.0%

Non-local 0.1% 0.0% 0.1% 0.0%

Hiking/Walking - Local 1.6% 0.7% 1.3% 0.8%

Non-local 4.1% 1.6% 3.2% 2.0%

Horseback Riding - Local 0.0% 0.0% 0.0% 0.0%

Non-local 0.0% 0.0% 0.0% 0.0%

Bicycling - Local 0.6% 0.3% 0.5% 0.3%

Non-local 1.6% 0.6% 1.3% 0.8%

Cross country Skiing - Local 0.6% 0.2% 0.4% 0.3%

Non-local 2.0% 0.8% 1.5% 1.0%

Other Non-motorized - Local 0.4% 0.2% 0.4% 0.2%

Non-local 1.1% 0.4% 0.9% 0.5%

Total Non-motorized 12.2% 4.8% 9.6% 6.0%
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

812 – Tahoe National Forest

Employment

(% of full & part-time jobs)

Labor Income (2008 dollars)

(% of Total Income)

Direct Indirect & 

Induced

Direct Indirect & 

Induced

Motorized Use

OHV Use - Local 0.3% 0.1% 0.2% 0.1%

Non-local 0.3% 0.1% 0.2% 0.2%

Driving for Pleasure - Local 0.4% 0.1% 0.3% 0.2%

Non-local 0.3% 0.1% 0.2% 0.1%

Snowmobiling - Local 2.1% 0.8% 1.6% 1.0%

Non-local 1.9% 0.7% 1.4% 0.9%

Other Motorized Activity - Local 0.3% 0.1% 0.2% 0.1%

Non-local 0.3% 0.1% 0.2% 0.2%

Total Motorized 5.8% 2.3% 4.5% 2.8%

All Other Use

All Other Activities - Local 20.2% 9.4% 19.8% 11.0%

Non-local 31.7% 13.8% 30.6% 15.7%

Total Other 51.7% 23.2% 50.4% 26.7%

Totals 69.7% 30.3% 64.5% 35.5%

100.0% 100.0%

Table 3.11-13a. Total Employment and Labor Income Effects

Employment Effects

(full and part time jobs)

Labor Income

(2008 dollars)

Total Non-Motorized Use Local 60 1,935,441

Non-Local 157 4,942,909

Total Motorized Use Local 53 1,697,010

Non-Local 50 1,547,471

Total All Other Use Local 373 13,647,240

Non-Local 579 20,418,470

Total Local 487 17,279,691

Non-Local 786 27,008,850

Total for Area 1,272 44,288,540
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

Tahoe National Forest – 813

Table 3.11-13b. Percent of Total Area Employment and Total Area Labor Income Effects

Employment Effects

(full and part time jobs)

Labor Income

(2008 dollars)

Total Non-Motorized Use Local 0.018% 0.012%

Non-Local 0.049% 0.033%

Total Motorized Use Local 0.009% 0.006%

Non-Local 0.009% 0.006%

Fishing Local 0.006% 0.004%

Non-Local 0.011% 0.008%

Hunting Local 0.002% 0.001%

Non-Local 0.001% 0.001%

Nature Related Local 0.004% 0.002%

Non-Local 0.011% 0.008%

Total All Other Use Local 0.074% 0.060%

Non-Local 0.107% 0.085%

Total Use 0.138% 0.088%

Study Area Total 545,090 25,277,393,000

Table 3.11-13a and 3.11-13b show the relationship of jobs and income generated from all recreation 

activities studied compared to total jobs and income in the 5 county area. All of the recreation jobs 

together only account for about 0.14% of the total jobs in the area, and the income generated is about 

0.09% of the total labor income in the area studied.

Predictions about changes in the amount of recreational use that may occur on the Forest are difficult 

to make and would be highly speculative. The Forest Service believes that under all action alternatives, 

levels of use would increase in the future by the same amount, although the use patterns may change. For 

example, even though the overall number of available roads and trails is reduced in all of the action 

alternatives, the same levels of use would simply become more concentrated in those available areas. 

However, motor vehicle use is already concentrated in some areas of the Forest, so this effect may not be 

realized either during implementation. However, at some point some users may not attain the experience 

they desire and would likely seek other areas off-forest. The point at which this would occur is 

speculative.

Seasonal closures on NFTS native surface (dirt) roads and motorized trails in Alternatives 4, 5 and 6 

are likely to have some level of impact to the local economy. Yet, this effect, again, is nearly 

immeasurable in relationship to the overall economy in the area. Any potential effects would likely impact 

gas stations, convenience stores, and other retail stores in local communities.

Environmental Justice

Community clusters are used to display how implementation of could affect people across the Region.

Community clusters are groups of communities that share a common economic history and environmental 

setting. The following factors form the basis for community clusters: watershed and basin boundaries; 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

814 – Tahoe National Forest

courses of highways, and proximity to the TNF. Table 3.11-14 displays those community clusters used in 

this analysis.

Table 3.11-14. Community clusters used to analyze economic and social impacts on communities

Community Cluster ZIP Code Community Community

Population

Eastern Sierra & Plumas Cos. 96015 Chilcoot 470

96118 Loyalton 1500

96124 Calpine 286

96126 Sierraville 355

96135 Vinton Not Available

Grass Valley/Nevada City 95945 Grass Valley 21,263

95946 Penn Valley 7603

95949 Grass Valley 20,973

95959 Nevada City 16,670

95960 North San Juan 228

95975 Rough and Ready 1811

96977 Smartville 807

West I-80 Corridor/Auburn 95603 Auburn 32,535

95631 Foresthill 4626

95658 Newcastle 5998

95701 Alta 751

95703 Applegate 1898

95713 Colfax 7344

95714 Dutch Flat 533

95715 Emigrant Gap 36

95717 Gold Run 79

95722 Meadow Vista 3314

Yuba River 95910 Alleghany Not Available

95918 Browns Valley 1297

95919 Brownsville 1013

95922 Camptonville 1090

95935 Dobbins 1502

95936 Downieville 46

95941 Forbsetown 517

95944 Goodyears Bar 377

95962 Oregon House Not Available

95972 Rackerby 260

95981 Strawberry Valley 242

96125 Sierra City 311
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

Tahoe National Forest – 815

Community Cluster ZIP Code Community Community

Population

East I-80 Corridor 89511 Reno (Rural Washoe) 16,421

95724 Norden 316

95728 Soda Springs 96

9611 Floriston 169

96161 Truckee 9544

96162 Truckee 199

Assumptions and Limitations

Diverse data sources were used to analyze impacts related to social issues. One particularly important 

source is data from the U.S. Census Bureau. These data provide details about economic and social 

characteristics of individual communities or community clusters in the TNF at a finer scale than the 

county level. Unfortunately, the data are 9 to 10 years old. This limitation may mean that economic and 

social conditions have changed in the intervening time. However, collecting new information is not 

essential to discern differences among alternatives or required for a reasoned choice among options.

Environmental Justice: Affected Environment 

Race, Cultural Heritage, Employment, and Income

The Tahoe National Forest community clusters have larger white populations than communities located 

just outside the Region. Table 3.11-15 shows percentages of people by racial composition and by 

Hispanic cultural heritage in the community clusters. None of the racial and cultural minorities when

combined comprise more than 10 percent of a cluster’s population in the TNF Region.

Table 3.11-15. Percentages of residents by race and Hispanic cultural heritage for Tahoe National Forest 

community clusters, 1990

Subregion and Community Cluster White Black American 

Indian

Asian Pacific 

Islander

Other Hispanic,

All Races

Eastern Sierra & Plumas Cos. 96.0 0.0 2.8 0.0 1.2 4.7

Grass Valley / Nevada City 97.1 0.3 1.2 0.7 0.6 3.9

West I-80 Corridor / Auburn 95.7 0.4 1.5 1.4 1.0 4.7

Yuba River 91.8 1.1 4.1 1.4 1.6 5.9

East I-80 Corridor 96.0 0.3 1.2 1.4 1.1 5.3

Source: US Census Bureau, 1990 Census Data

Per capita income figures show that in general racial and cultural minority groups in the TNF Region 

earn less than their white neighbors. Table 3.11-16 displays per capita incomes of racial and cultural 

groups in each community cluster. Figures are in bold where race or heritage based per capita incomes fall 

below half the per capita incomes of whites. Per capita incomes of all minority groups combined (Black, 

American Indian, Asian and Pacific Islander, and others) are less than half the per capita incomes for 

whites in the Yuba River community cluster. 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

816 – Tahoe National Forest

Table 3.11-16. Per capita incomes of residents in Tahoe National Forest community clusters by ethnicity and 

cultural heritage, 1989

Subregion and

Community Cluster

White Black American 

Indian

Asian and 

Pacific 

Islander

Other Combined 

Racial

Minorities

Hispanic, 

All 

Races

Percent 

Jobs in 

Services 

Sector in 1989 dollars

Eastern Sierra & 

Plumas Cos.

11,714 NA 8,683 NA 5,006 7,580 11,601 10.1

Grass Valley/

Nevada City

15,561 4,426 8,858 13,784 10,814 10,034 10,081 3.6

West I-80 Corridor/ 

Auburn

15,938 19,117 11,109 24,163 11,127 16,108 14,317 2.5

Yuba River 12,917 8,894 5,532 3,848 9,360 6,442 15,893 14.1

East I-80 Corridor 20,700 20,378 14,801 12,549 15,552 14,638 12,033 2.1

Source: US Census Bureau, 1990 Census

Community Clusters at Risk: Community clusters at risk from consequences stemming from the 

alternatives proposed in this EIS have certain characteristics related to poverty; poverty in relation to race 

or cultural heritage, historical unemployment, and types of employment. Community clusters of greatest 

socioeconomic concern meet at least one of the following four criteria:

1. More than 10 percent of the cluster’s population is comprised of minority racial groups that 

combined have per capita incomes that are no more than half of whites’ per capita income;

2. More than 10 percent of the cluster’s population is comprised of Hispanics and Hispanic per 

capita income is no more than half of whites’ per capita income;

3. Per capita income for whites in a community cluster is less than $10,350; (This figure is half of 

the per capita income of the community cluster (East I-80 Corridor) with the highest white per 

capita income ($20,700) in the TNF Region.)

4. More than 10 percent of the jobs in the cluster are in the services sector (as a surrogate for 

recreation).

These criteria identify elements of concern for social impacts in rural communities in several ways.

Criteria 1 and 2 identify minority populations, comprising at least 10 percent of the total population that

live under marked economic inequalities. Criterion 3 speaks to relative unevenness of wealth distributed 

across the Sierra Nevada Region for all people. Unemployment differs considerably among Sierra Nevada 

Region communities. Communities that currently have the highest unemployment have consistently had 

high unemployment (from 1990 to 1998) despite economic turnarounds in other parts of California.

Forest Service opportunities for motorized wheeled vehicle recreation may influence employment in the 

services sectors in the community clusters. Criterion 4 identifies communities with a high dependence 

upon the services sector. The community clusters at risk based on these criteria are displayed in Table 

3.11-17.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

Tahoe National Forest – 817

Table 3.11-17. Community clusters of concern based on income by ethnic or cultural heritage group, sources 

of employment, and percent unemployment

Community Cluster Qualifying Criteria

Eastern Sierra and Plumas Cos. 1

Yuba River 2

Children in Poverty

Children are one population group that is disproportionately represented within low-income families. 

Table 3.11-20 shows U.S. Census Bureau estimates for all people living in poverty and for children living 

in poverty in counties of the TNF Region. Children are all people less than 18 years old. The U.S. Census 

Bureau defines poverty based on threshold incomes for families of different sizes. Thresholds change 

yearly and do not vary geographically.

The percentages of children living in poverty in the TNF Region are all below State averages with the 

exception of Yuba County. More than one-third of the children in Yuba County live in poverty. None of 

the counties in the TNF Region that have adults living in poverty comprise more than one-third of the 

total adult population. 

The California Department of Education monitors the number of enrolled school children receiving 

supplemental benefits through Aid to Families with Dependent Children and through free or reducedprice meals. Table 3.11-20 summarizes data for school-age children at schools in the Tahoe National 

Forest Region.

Table 3.11-18. All people and all children living in poverty in the TNF Region counties, 1996

County Number of All People 

Living in Poverty

Percent of People 

Living in Poverty

Number of Children 

Living in Poverty

Percent of Children 

Living in Poverty

Plumas 2,552 12.2 1,094 19.3 

Sierra 326 9.4 102 10.6 

Nevada 8,456 9.4 3,145 13.6 

Placer 16,376 7.6 6,268 10.3 

Yuba 13,964 22.8 7,279 34.0 

All CA 5,215,575 16.5 2,214,535 24.3 

Note: Children are considered to be all people less than eighteen years old.

Source: US Census Bureau (1999) based on a 1995 demographic model and 1996 populations.

Childhood Education

Table 3.11-19 presents the most recent available figures for primary and secondary public schools 

attended by pupils living in the Tahoe National Forest region. The table shows that, between the 1992-93 

and 1997-98 school years, schools in the Region stabilized or reduced pupil-to-teacher ratios and also 

provided 2.3 percent more school meals to pupils for free or at a reduced price. These accomplishments 

occurred at the same time that many counties were seeing increases in their enrollments. For example, 

Placer County saw increases of 10 percent or more.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

818 – Tahoe National Forest

Table 3.11-19. Enrollment, poverty status, pupil-teacher ratios, and expenditures per pupil for schools 

attended by pupils living in Sierra Nevada Region

County Enrolled Students Children 

in 

Poverty*

Percent of Pupils in 

Families Receiving AFDC 

Payments

Pupil-to-Teacher Ratio Per Pupil

Spending

1992-93 1997-98 Percent 

Change

1996 1992-93 1997-98 Percent 

Change

1992-93 1997-98 Percent 

Change

1996-97

Plumas 3,875 3,617 -6.7 18.2 13.0 10.4 -2.6 22.4 20.0 -2.4 5,500

Sierra 829 1,592 92.0 10.6 6.4 4.1 -2.3 18.1 16.8 -1.3 7,950

Nevada 12,644 13,378 5.8 12.4 9.2 7.6 -1.7 22.9 20.5 -2.3 5,330

Placer 17,607 20,098 14.1 9.8 7.7 6.0 -1.8 24.2 20.8 -3.4 5,108

Yuba 125 82 -34.4 20.2 23.2 28.0 4.8 23.0 17.1 -5.9 6,950

Source: US Census Bureau and California State Department of Education

* Pupils from parts of counties outside of the Sierra Nevada Region are not included in these totals. Some high schools attended by 

Sierra Nevada Region pupils, however, lie outside the Sierra Nevada Region. High schools attended by Sierra Nevada Region 

pupils are included in totals, except in Yuba County.

AFDC: Aid to Families with Dependent Children

Payments to the TNF Region counties from Forest Service timber sales, expressed in constant year 

dollars, have declined. Counties with declines of more than 70 percent between 1992 and 1997 include 

Plumas and Yuba. With growing enrollments and reduced funds from Forest Service revenues, these 

counties, in particular, may experience greater fiscal constraints to meet mandates and societal 

expectations for public school performance. Children, especially poor children, in these counties may 

receive diminished educational benefits.

To meet the shortfall in Forest Service receipts, President Clinton signed into law the Secure Rural 

Schools and Community Self-Determination Act of 2000 on 30 October 2000. This law gives counties the 

option, instead of 25 percent of current year receipts, of receiving annual payments from the U.S. Forest 

Service and other federal agencies based on the average of the three highest annual payments for the 

period 1986 to 1999. See Table 3.11-20. An annual increase above the three-year average adds value up to 

50 percent of the annual increase in the National Consumer Price Index in each successive year.

Table 3.11-20. Changes in Forest Service payments (in 1995 dollars) to Sierra Nevada Region counties, 1992 

and 1997

Subregion and County Total Forest Service Payments

1992 1997 Percent Change

Plumas 9,521,606 1,659,323 -82.6

Sierra 1,723,426 874,447 -49.3

Nevada 664,716 405,126 -39.1

Placer 1,486,525 739,943 -50.2

Yuba 283,674 75,090 -73.5

USDA Forest Service Records of Payments to California and Nevada counties.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

Tahoe National Forest – 819

Results from Scholastic Aptitude Tests (SATs) provide one measure of how well public education 

prepares its students for higher education at colleges and universities. Many people are concerned about 

how reduced receipts to counties related to National Forest timber sales may have affected counties’ 

spending on educational services for students and ultimately student performance. Table 3.11-21 ranks 

high schools attended by Sierra Nevada Region students attend based on each school’s combined average 

scores in reading comprehension and mathematical skills.

Table 3.11-21. Combined Average Scholastic Aptitude Test (SAT) scores for High Schools Attended by Sierra 

Nevada Region Students

High School 

Name

High School 

Location

(CA Unless

otherwise noted)

Percent 

taking

SAT 

1989

Aver.

Combined

SAT 

Score 

1989

Percentile 

Rank

1989

Percent 

taking

SAT 

1998

Aver. 

Combined

SAT Score 

1998

Percentile 

Rank

1998

All CA & 

NV

Change 

in

Ranking

Nevada Union 

High

Grass Valley 33.3 1054 76 44.9 1094 82 6

Colfax High Colfax 28.1 1067 80 46.2 1062 73 -6

Placer High 

(Char)

Auburn 24.7 1048 74 39.5 1059 72 -1

Tahoe Truckee 

High

Truckee 35.3 1020 64 51.9 1058 72 8

Del Oro High Auburn 26.7 1070 81 40.7 1048 69 -11

Bear River 

High

Grass Valley 33.1 1012 61 46.2 1030 64 3

Loyalton High Loyalton 32 969 47 51.6 1006 58 11

North Tahoe 

High

Truckee 44.8 1020 64 73 1003 57 -7

Downieville 

Junior-Senior 

High

Downieville 54.5 1086 86 75 936 39 -47

Community Needs for Fuel Wood

Fuel wood supplies are critical to rural people in California with low incomes. Data about fuel wood 

demand and supply in TNF Region counties are not available at present. Just outside the Region, in 

Trinity County, California, however, more than 70 percent of households rely on wood heating for their 

home (Celia Danks, Hayfork GIS Center, Hayfork, CA, personal communication April 1999). Smoke 

from domestic wood stoves may worsen local air quality during the winter and early spring that in turn 

may damage the health of children and elderly people nearby.

Environmental Justice: Environmental Consequences

Predictions about changes in the amount of recreational use that may occur on the Forest are difficult to 

make and would be highly speculative. The Forest Service believes that under all action alternatives, 

levels of use would increase by the same amount in all alternatives although the use patterns may change. 

For example, even though the overall number of available roads and trails is reduced in all of the action 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

820 – Tahoe National Forest

alternatives, the same levels of use would simply become more concentrated in those available areas. 

However, motor vehicle use is already concentrated in some areas of the Forest, so this effect may not be 

realized either during implementation. However, at some point some users may not attain the experience 

they desire and would likely seek other areas off-forest. The point at which this would occur is 

speculative.

Seasonal closures on NFTS native surface (dirt) roads and motorized trails in Alternatives 4, 5 and 6 

are likely to have some level of impact to the local economy. Yet, this effect, again, is nearly 

immeasurable in relationship to the overall economy in the area. Any potential effects would likely impact 

gas stations, convenience stores, and other retail stores in local communities.

Race, Cultural Heritage, Employment, and Income

The potential impacts from changes in recreation use levels to minority and poor communities are likely 

to be greater in the Eastern Sierra and Yuba River clusters. These community clusters would be 

particularly sensitive to potential economic changes associated with the alternatives. These clusters are 

either the poorest community clusters in the Sierra Nevada Region and have traditionally had significant 

employment tied to the services industry or sizable minority populations.

Children in Poverty

Children may disproportionately suffer from economic decisions of the Forest Service if their parents lose 

jobs or must take lower paying jobs.

Childhood Education

The Secure Rural Schools and Community Self-Determination Act of 2000 gives the counties the option 

to receive payments based in the highest five years receipts from 1986 to 1999. This program is for five 

years, so during that period, county education budgets will not be impacted.

Other social and economic factors in communities or other Federal and State funding may have more 

influence more the ability of public education systems in the Region to prepare their students for higher 

education than the Forest Service.

Community Needs for Fuel Wood

Most individuals use wheeled motorized vehicles to gather personal use fire wood. Those alternatives 

which provide the largest miles of roads open to wheeled motor vehicles for the longest period would

provide the greatest opportunity for fuel wood gathering. Table 3.11-22 shows the miles of roads 

available by vehicle class and season.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

Tahoe National Forest – 821

Table 3.11-22. Miles of roads available for fuel wood gathering opportunities by time of year

Access for Fuel wood Gathering Opportunities (miles)

Class of Vehicle Season of Use Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Roads Open to Highway Legal 

Vehicles Only

All Year

351.4 141.4 351.4 348.1 141.4 230.2 348.1

Roads Open to Highway Legal 

Vehicles Only

Seasonal 

Restriction 265.3 76.9 265.3 265.3 76.9 251.5 265.3

Roads Open to All Vehicles All Year 1044.0 1268.2 1044.0 0.0 132.6 4.6 1048.3

Roads Open to All Vehicles Seasonal 

Restriction 406.9 586.0 406.9 1457.9 1801.1 1597.1 406.9

Summary of Environmental Justice in the Sierra Nevada Region

Table 3.11-23 summarizes Forest Service concerns for social impacts and environmental justice in Sierra 

Nevada community clusters analyzed in this EIS. Eastern Sierra and Plumas Counties are at risk for 

disproportional effects from the alternatives based on two criteria; 1) Race, cultural heritage and income 

and 2) Community Needs for Fuel Wood. The Yuba River community cluster is at risk for disproportional 

effects from the alternatives based on three criteria; 1) race, cultural heritage and income, 2) Children in 

Poverty and 3) Community Needs for Fuel Wood. There is no risk for disproportional effects from the 

alternatives based on any of criteria of any of the other community clusters.

Table 3.11-23. Summary of Forest Service Civil Rights Impact Analysis and environmental justice by 

community clusters in the Sierra Nevada Region

Subregion and 

Community Clusters

Race, Cultural Heritage, 

Employment, and 

Income

Children 

in 

Poverty

Childhood 

Education

Community 

Needs for

Fuel Wood

Barriers to 

Communication

Eastern Sierra & Plumas 

Counties

Yes No No Yes No

Grass Valley/Nevada City No No No No No

West I-80 Corridor/Auburn No No No No No

Yuba River Yes Yes Yes Yes No

East I-80 Corridor No No No No No

Social Impact Analysis: Affected Environment

For the TNF, two social groups have been identified as likely to be affected by the Travel Management 

alternatives. These groups generally place different demands and have different values regarding 

management of motor vehicle use in the TNF. These groups were identified through a variety of sources

including: The Public Collaboration Meetings held prior to the Notice of Intent (NOI), scoping comments 

received on the proposed action in the NOI, public meetings held during the scoping period, public 

comments received on the Draft EIS, public meetings held during the comment period on the Draft EIS, 

as well as various other meetings held with individuals or organizations. The identified groups are not 

mutually exclusive. They are, however, useful for analysis. The different social groups would be affected 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

822 – Tahoe National Forest

differently by the various alternatives. Although grouping may produce some incorrect stereotyping, 

generally the following characteristics apply to these groups.

Motorized Use Advocates

One group perceived this action as restrictive in nature. They viewed the proposed action as unreasonably 

restricting motorized recreation use by prohibiting cross country travel and only adding 70.3 miles of 

additional NFTS motorized recreation opportunities. Concerns were raised that restricting cross country 

travel across the entire Forest severely impacts motorized recreation opportunities and unfairly restricts 

access for hunting, fishing, camping and a host of other outdoor activities. Several individuals commented 

on specific roads that they use and have used historically which they would like to have added to the 

NFTS.

Non-motorized Use Advocates

Another group of commenters expressed the desire to see the Forest be more restrictive and protective of 

the resources and that many of the motorized trails proposed for addition to the NFTS are poorly located 

and would cause adverse impacts to plants, wildlife, water quality, soils and other natural resources.

Many commenters expressed concerns about impacts to a variety of natural resources, citing stream 

crossings, habitat fragmentation, wildlife disturbance, sedimentation, cultural resources, invasive weeds 

and other resources that would be impacted by motorized use or roads and trails. A group also expressed 

concerns that the proposed addition of motorized trails to Inventoried Roadless Areas would adversely 

affect roadless characteristics of these areas including opportunities for solitude, undisturbed landscapes 

and primitive, non-motorized recreation.

Social Impact Indicators

Lifestyles

This variable includes the ways people live; patterns of work and leisure, customs and traditions, and 

relationships with family and friends. Aesthetic amenities (e.g., open space, scenery, quiet) and recreation 

opportunities both motorized and non-motorized are affected by the Travel Management alternatives.

Attitudes, beliefs and values

This variable refers to the feelings, preferences, and expectations people have for the TNF and the 

management and use of certain areas. It may include the group’s sense of freedom or self-sufficiency and 

their feeling of certainty or uncertainty about the future. The former includes changes in perceived control 

by outside interests, perceived capability of local government to meet their needs, and the group’s sense 

of whether they can meet their recreation needs from the Forest. Feelings about the future may be affected 

by rates of change caused by Forest Service management and the predictability of consequences of the 

change.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

Tahoe National Forest – 823

Social Impact Analysis: Environmental Consequences

Social and economic consequences are closely related. (Income and employment effects are discussed 

earlier in this chapter) Social effects are expressed through the evaluation of lifestyles; attitudes, beliefs 

and values. The affected groups include motorized and non-motorized use advocates.

Implementing the alternatives would have social consequences. When the groups within the Forest 

sphere of influence differ significantly in their expectations for Forest recreation use and when the 

alternatives have different effects on the social groups, potential conflict exists. Generally, the smaller the 

range of alternative choices, the less the conflict between social groups.

For example alternatives which prohibit cross country travel are most beneficial to non-motorized use 

advocates. On the other hand, alternatives which emphasize motorized recreation opportunities are most 

acceptable to motorized use advocates.

The two social groups are the focus of the discussion that follows. Table 3.11-24 displays the social 

effects for each group by indicator measure and alternative.

Table 3.11-24. Summary of impacts to social groups by alternative

Indicator Measure Social Group Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Lifestyles Motorized Use Advocates SS GS LS LS GS GS GS

Non-motorized Use Advocates LS LS GS GS LS GS GS

Attitudes, Beliefs 

and Values

Motorized Use Advocates SC GC LC LC GC GC GC

Non-motorized Use Advocates LC LC GC GC LC GC GC

Legend

LS – Alternative provides “Little Support” for the lifestyle of the group

GS – Alternative “Generally Supports” the lifestyle of the group

SS – Alternative “Substantially Supports” the lifestyle of the group

LC – “Least Coincides” with the group’s attitudes beliefs and values

GC – Generally Coincides with the group’s attitudes beliefs and values

SC – “Substantially Coincides” with the group’s attitudes beliefs and values

Direct and Indirect Effects

If the prohibition of cross country travel is implemented it may negatively impact motor vehicle users on 

the TNF. This action may affect the very young and the very old by preventing them from participating in 

activities that require strenuous walking for access. This same action may enhance the recreation 

opportunity for non-motorized users. This may cause resentment between user groups. The addition of 

roads and trails to the NFTS may appeal to users who recreate by driving or riding for pleasure. However, 

this may negatively affect the non-motorized users because of concerns of impacts to plants, wildlife, 

water quality, soils and other natural resources.

Cumulative Effects

Based on historic data and our best estimates, the Forest assumes that use would not change dramatically 

in the future because of this project; however, use could increase as population increases. It is also
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

824 – Tahoe National Forest

assumed, that under all action alternatives, levels of use would increase by the same amount; although the 

use patterns may change. For example, even though cross country travel is prohibited in all of the action 

alternatives, the same levels of use would simply become more concentrated on roads.

Based on the current numbers and these assumptions, the possibility of conflict between user groups 

is probably the most constant cumulative effect socially and may be present regardless of which 

alternative is chosen.

Civil Rights Impact Analysis

USDA civil rights policy requires each agency to analyze the civil rights impact(s) of policies, actions, or 

decisions that will affect federally conducted and federally assisted programs and activities. A civil rights 

impact analysis (CRIA) facilitates the identification of the effects of eligibility criteria, methods of 

administration, or other agency-imposed requirements that may adversely and disproportionately impact 

employees or program beneficiaries based on their membership in a protected group. Protected groups 

include multiples of similarly situated persons who may be distinguished by their common race, color, 

national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, 

religion, sexual orientation, genetics, political beliefs, or receipt of income from any public assistance 

program.

Restrictions on motor vehicle use that are applied consistently to everyone are not discriminatory.

However, some groups could be impacted more than others. This assessment addresses such concerns.

Public Involvement and Scoping

Public involvement concerning this proposal began with travel analysis that focused on the identification 

of unauthorized routes and assessing the effects of prohibiting cross country motorized travel on Forest 

users. This initial phase of public involvement began on October 19, 2006 and included six workshops to 

identify which routes and areas should become part of the “Proposed Action.” On October 19 (Nevada 

City), October 23 (Truckee), and October 26 (Foresthill), the public broke into three groups to review 

three different geographical areas and to discuss which of the routes should or should not become part of 

the proposal. Some of the groups continued to meet and/or to make field visits to review conditions on the 

ground. On November 15 (Grass Valley), December 5 (Truckee) and December 7 (Foresthill), the groups 

shared their ideas and their various concerns to the general public. Roughly 300 people participated in 

these workshops. In 2007, an e-mail update was issued sharing information on the meetings and outcome.

These workshops were open to the general public including minorities, woman, and people with 

disabilities. The facilities where the workshops were held were ADA compliant.

Public scoping for this EIS began with a NOI published in the Federal Register on April 11, 2007.

Scoping for the proposal was conducted through May 14, 2007. Scoping efforts included presentations to 

a variety of groups, phone calls, news releases, website postings and emails to alert the public of the 

opportunity to comment on the Proposed Action. Public meetings were held in Truckee (April 18, 2007), 

Foresthill (April 24, 2007) and Grass Valley (April 26, 2007) to explain the Proposed Action. Over 3,500 

comments were received via e-mail and regular mail, most being e-mail form letters.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

Tahoe National Forest – 825

An 88-day comment period on the DEIS was completed on December 29, 2008. During the comment 

period public meetings were held in Nevada City (Oct. 1, 2008), Sierraville (Oct. 3), Olympic Valley 

(Oct. 7, 2008), and Auburn (Oct. 9, 2008) to discuss the DEIS. Over 7,000 comments were received via email and regular mail, most being e-mail form letters.

Concerns and Mitigations Related to Potential Civil Rights Impacts

Through these public involvement efforts and interdisciplinary discussions, several concerns were raised 

and are addressed below.

Gathering Special Forest Products

It is known that many people, including members of protected groups, use motor vehicles to gather 

Special Forest Products including mushrooms, greenery, firewood, posts, poles, etc. Such products are 

gathered for both personal and commercial use. Some protected groups are known to be very active in 

gathering certain Special Forest Products. Concerns have been raised that the prohibition on cross country 

travel will restrict such activities to designated roads or trails, limit people’s ability to gather such 

products and disproportionately impact protected groups.

Currently, under 36 CFR 261.6, removing any timber, tree or other forest product, except as 

authorized by a special-use authorization, timber sale contract, or Federal law or regulation is prohibited.

Gathering special forest products requires written authorization by the Forest Service. Such permitted 

activities are exempt from the prohibition on cross country travel in accordance with provisions of the 

permit (36 CFR 212.51 (8)). Such activities have been, and will continue to be, subject to separate, sitespecific National Environmental Policy Act analysis, before permits are issued. This proposal does not 

change that policy. Permits will continue to be issued in accordance with law, regulation and policy 

regardless of this proposal. Therefore, it is not expected that gathering special forest products will be 

affected by this proposal or that any protected groups will be disproportionately affected.

Impacts on People with Disabilities and the Elderly

Throughout scoping, concerns have been raised about the impact of this project on people with disabilities 

and the elderly. Commenters have asserted that the proposal unfairly discriminates against these groups 

because they are more dependent on motor vehicles to access and enjoy our National Forests.

Comments from people with disabilities and the elderly, including references to specific sites or 

locations, were considered in the development of alternatives. Recreation opportunities and access needs 

for all users are some of the criteria used in the process of developing the selected alternative.

Implementation of the Travel Management Rule, Subpart B, including the prohibition of cross 

country travel, would be Forest-wide and applies to all Forest users equally. Changes to the NFTS would 

be largely limited to changes in vehicle class and season of use. Motorized access on NFTS routes is 

expected to be enhanced by the addition of unauthorized routes and the addition of vehicle classes on 

routes where such use has been prohibited.

There is no legal requirement to allow people with disabilities to use motor vehicles on roads, on 

trails, and in areas that are closed to motor vehicle use. Restrictions on motor vehicle use that are applied 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

826 – Tahoe National Forest

consistently to everyone are not discriminatory. Generally, granting an exemption from designations for 

people with disabilities would not be consistent with the resource protection and other management 

objectives of travel management and would fundamentally alter the nature of the Forest Service's travel 

management program (29 U.S.C. 794; 7 CFR 15e.103).

Under section 504 of the Rehabilitation Act of 1973, no person with a disability can be denied 

participation in a Federal program that is available to all other people solely because of his or her 

disability. Consistent with 36 CFR 212.1, FSM 2353.05, and Title V, Section 507(c), of the Americans 

With Disabilities Act, wheelchairs and mobility devices, including those that are battery-powered, that are 

designed solely for use by a mobility-impaired person for locomotion and that are suitable for use in an 

indoor pedestrian area are allowed on all NFS lands that are open to foot travel.

Further, the Selected Alternative includes those additions to the NFTS that were identified as being of 

special importance to the elderly and disabled. These additions include ARM-3r (family oriented 

ATV/motorcycle), YRS-B5 (low difficulty motorcycle), TKN-J5 (4wd access to views along Sierra crest), 

access to the shoreline at Boca, Prosser and Stampede Reservoirs, and numerous routes accessing 

dispersed recreation sites.

Access by American Indians

Concerns were raised by American Indians and tribal representatives that this proposal would unduly 

restrict access to sacred sites or traditional gathering areas that are accessed via motorized cross country

travel, including unauthorized routes. Elderly or infirm tribal members may be prevented from 

participating in tribal activities if motor vehicle access is denied. Such access has been traditionally 

granted as long as resource damage can be prevented.

Motor vehicle use that is specifically authorized under a written authorization issued under Federal 

law or regulations is exempt from route designations (36 CFR 212.51 (8)). Therefore, motor vehicle 

access to sacred sites or gathering areas may be authorized by the Forest Service and will not be affected 

by this proposal. 

Further, throughout the Travel Management Project, comments were solicited but not received from 

federally recognized and unacknowledged tribes, intertribal organizations, and individuals. The following 

Table 3.11-25 is a summary of the communications to date with American Indian Tribes.

Table 3.11-25. American Indian Tribes Communications

Tribe When

T’si-Akim Maidu, Donald Ryberg; Washoe Tribal Council, Brian Wallace; 

United Auburn Indian Community, Jessica Taverrs; Colfax-Todd Valley 

Consolidated Tribe, Richard Prout; Todd Valley Miwok-Maidu Cultural Foundation, 

Brigette Zellner; Greenville Rancheria, Lorie Jaimes; California Indian 

Basketweavers Association, Sara Greensfelder, and Wadatkuht Band of the 

Northern Paiutes of the Honey Lake Valley, Harold Dixon.

March 15, 2005 (letters, 

e-mails, and phone calls)

United Auburn Indian Community, Yolanda Chavez of Environmental Services April 26, 2007 (phone call)

Ms. Shannon Brawley, Executive Director, California Indian Basket Makers 

Association

April 13, 2007 (letter)
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

Tahoe National Forest – 827

Tribe When

United Auburn Indian Community (UAIC), Yolanda Chavez of Analytical 

Environmental Services

July 5, 2007 (phone call)

United Auburn Indian Community (UAIC) July 10, 2007 (meeting)

Mike DeSpain, Greenville Rancheria Environmental Coordinator May 4, 2007 (phone call)

Waldo Walker, Washoe Tribe of Nevada and California March 18, 2008 (letter)

Jessica Tavares, United Auburn Indian Community March 18, 2008 (letter)

Lavina Suehead, Colfax Todd Valley Consolidated Tribe March 20, 2008 (letter)

Don Ryberg, T’si-Akim Maidu March 20, 2008 (letter)

Bridget Zellner, Todd Valley Miwok-Maidu Cultural Foundation March 20, 2008 (letter)

Darrel Cruz, Washoe Tribe of Nevada and California May 27, 2008 (phone call)

Darrel Cruz, Washoe Tribe of Nevada and California July 3, 2008 (meeting)

Lorie James and Mike DeSpain, Greenville Rancheria; Don Ryberg, T’si Akim 

Maidu; Waldo Walker, Washoe Tribal Council; United Auburn Indian Community; 

Levina Suehead, Colfax-Todd Valley Consolidated Tribe; Brigette Zellner, Todd 

Valley Miwok-Maidu Cultural Foundation; Harold Dixon, Wadatkauht Band of the 

Northern Paiutes of the Honey Lake Valley.

February 12 , 2009 (letter)

Impacts on People with Limited English Proficiency

In California, people of Hispanic origin comprise a large part of the population and enjoy access to the 

National Forests for a variety of recreation and business pursuits. Many of these users speak English as a 

second language and therefore may have limited ability to read maps or other publications pertaining to 

travel management. In particular, the Forest Motor Vehicle Use Map (MVUM) is a concern since the 

MVUM will be the basis for enforcing vehicle restrictions. NFTS routes that are open for public use will 

be designated on the MVUM and users that leave designated routes will be subject to fines. There is a 

concern that people with limited English proficiency will be more vulnerable to citation if they are unable 

to read or understand the MVUM.

As the population of the Sierra Nevada Region grows, the ethnic composition of its residents will 

change as well. The population of the TNF Region is expected to more than double over the next 50 

years. At the same time, the number of Hispanic residents is projected to grow at a greater rate than the 

number of white residents. Proportions of other ethnic groups, except whites, are expected to remain 

essentially the same. In order to lessen potential negative impacts to Spanish speaking people, the Tahoe 

National Forest will publish the MVUM in both Spanish and English.

Summary of Effects Analysis across All Alternatives

Table 3.11-26 summarizes the effects analysis for the social and economic environment by ranking each 

alternative regarding how well it provides for each of the indicators. This summary is not meant to convey 

that the indicators are equal in importance. The following rankings were used: A score of 7 indicates the 

alternative has the least impact for the social economic environment to the indicator. A score of 1 

indicates the alternative has the most impact for the social economic environment related to the indicator. 

A score of 0 indicates the indictor does not apply.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 3: Affected Environment & Environmental Consequences – 3.11. Society, Culture & Economy

828 – Tahoe National Forest

Table 3.11-26. Comparison of Effects to the Social Economic Environment

Indicator Alt 1 Alt 2 Alt 3 Alt 4 Alt 5 Alt 6 Alt 7

Employment and Income 0 0 0 0 0 0 0

Environmental Justice 0 0 0 0 0 0 0

Motorized Use Advocate Lifestyles 7 5 1 2 6 4 3

Non-motorized Use Advocate Lifestyles 1 3 7 6 2 4 5

Motorized Use Advocate Attitudes, Beliefs and 

Values

7 5 1 2 6 4 3

Non-motorized Use Advocate Attitudes, Beliefs 

and Values

1 3 7 6 2 4 5

Civil Rights Impacts 0 0 0 0 0 0 0

Average 4.0 4.0 4.0 4.0 4.0 4.0 4.0
Chapter 4 

Consultation and Coordination 

Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Tahoe National Forest – 829

Chapter 4: Consultation and Coordination

The public involvement process for the travel management process was designed to be open, inclusive, 

and interactive and to involve many diverse interest groups, individuals, agencies, and Native American 

Tribes. The public involvement process began in 2004 and continues through 2010. Public and group 

meetings, open houses, presentations, newsletters, web updates, news releases/interviews with media and 

personal discussions were all used to maintain regular communication with those interested/affected by 

this project. In addition, throughout this multi-year process, hundreds upon hundreds of public questions 

and concerns were answered and discussed with the public by the ID Team and other employees via the 

phone, in face-to-face meetings, field reviews, and through electronic or hard mail. Over 5,000 individual 

email addresses have been included in TNF/RO travel management mailing lists to receive updates on 

this process.

Truckee Pilot Project_____________________________________

Initially titled the Route Designation process, the Forest Service began travel management with a 95,000 

acre area near Truckee as a pilot. In the summer of 2004, the Forest Service began public involvement 

regarding the project. Public meetings were held in Nevada City (November 8, 2004) and Truckee 

(November 10, 2004) to share maps of the inventoried trails, routes, and roads and answer questions. The 

public was requested to review the maps of the inventoried trails or routes and to identify any missing or 

incorrectly identified routes. Approximately 80 people attended the two public meetings and many 

requested additional time to review the maps. Presentations were also made to a variety of interest groups 

in the Truckee and Nevada City areas including motorcycle, four-wheel drive, mountain bike, and 

environmental groups. A poster explaining the process and map for review were distributed to a variety of 

bicycle, motorcycle, and sporting goods stores in the Truckee, Reno, Nevada City and Grass Valley areas 

for display. An e-mail list was initiated to share progress and information about this project.

Public Involvement Expanded to the Entire Forest ____________

Due to an early snowfall and public requests for more time to review the maps, the pilot project was 

delayed. The schedule for the Truckee pilot was subsequently combined with the rest of the Forest for a 

forest-wide travel management planning effort.

In 2005, maps of the existing roads, trails, areas, and routes were placed on the Forest website. Five 

additional public meetings were held during the summer to provide an overview of the planning process 

and to obtain public review of maps. Meetings were held in Downieville (August 24, 2005), Sierraville 

(August 30, 2005), Truckee (August 29, 2005), Nevada City (August 31, 2005) and Foresthill (August 26, 

2005). Approximately 115 people attended these meetings. Seventeen individuals commented in writing 

on errors or omissions of ninety routes. Another newsletter was issued and sent out electronically to 

explain the process and encourage review of the on-line maps.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 4: Consultation and Coordination

830 – Tahoe National Forest

Identifying Important Trail Criteria _________________________

In 2006, an on-line survey was initiated to identify trail users preference for trails – both motorized and 

non-motorized. Over 800 people participated in this survey. The information obtained from this survey 

helped the Forest Service better understand what trail criteria was most important for motorized and nonmotorized trail users.

Designing Public Involvement for

Helping Develop Proposed Action _________________________

During the summer, 2006, a variety of motorized and non-motorized trail users provided suggestions on 

designing a public participation process that would be meaningful to the public in helping identify a 

starting point from which to build the “Proposed Action.” Approximately 20 individuals provided 

suggestions for this part of the public involvement process.

Workshops to Obtain Public Ideas on Proposed Action________

In the fall, 2006, using the suggestions from the public on how to structure the public involvement, a 

series of six workshops were initiated to identify the routes and areas the public desired to be included in 

the “Proposed Action.” The topic of “mixed use” was also introduced during these meetings. At the first 

session of the 2-part series, workshops were held in Nevada City (Oct 19, 2006), Truckee (Oct 2, 2006) 

and Foresthill (Oct 26, 2006). At these meetings, participants broke into three groups to review three

different geographical areas and to discuss which of the unauthorized routes should or should not become 

part of the proposal. Some of the groups continued to meet and/or to make field visits to review 

conditions on the ground. Later in the fall, at the second set of workshops, the sub-groups presented their 

information back to the entire group at sessions in Grass Valley (Nov 15, 2006), Truckee (Dec 5, 2006) 

and Foresthill (Dec 7, 2006). Groups shared their ideas and their various concerns with other group 

proposals. Roughly 300 people participated in these workshops. In early 2007, an e-mail update was 

issued sharing information from the workshops and the outcome. Slides showing the groups 

recommended trails were posted on the website.

Proposed Action and Notice of Intent to Prepare an

Environmental Impact Statement __________________________

In April, 2007, the Forest Service completed the “Proposed Action and Notice of Intent to Prepare an 

Environmental Impact Statement” based on comments from the meetings held in the fall. Public Scoping

began on April 11, 2007. Presentations to a variety of groups, phone calls, news releases, website postings 

and email updates were used to alert the public of the opportunity to comment on the Proposed Action.

Public meetings were held in Truckee (April 18, 2007), in Foresthill (April 24, 2007) and in Grass Valley 

(April 26, 2007) to explain the Proposed Action. Over 3,500 comments were received during April and 

May.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 4: Consultation and Coordination

Tahoe National Forest – 831

Additional newsletters were e-mailed to the individuals on the mailing list explaining the process 

used for reviewing the public scoping comments and requesting feedback as to how the public would like 

to review the Draft Environmental Impact Statement (hard copy, on line, or via CD). In May 2008, a 

meeting with motorized and non-motorized participants was held to listen to their suggestions as to the 

design of public meetings during the release of the Draft EIS. Additionally, small business cards were 

developed for field going personnel to give to OHV riders and other recreationists encountered in the field 

which described this process and invited their participation.

Draft Environmental Impact Statement __________________________ 

In the fall, 2008, the public was notified that the Draft EIS would be available for review and that open 

houses/meetings would be held. On September 26, news releases and email updates were mailed along 

with hard-copies of the DEIS to those that requested them. The document and maps were available as a 

hard copy, a CD, or on the web.

Four open houses along with corresponding public meetings were held in: Nevada City (Oct 1, 2008), 

Sierraville (Oct 3, 2008), Truckee/Olympic Valley (Oct 7, 2008), and Auburn (Oct 9, 2008). Open houses 

were held in the afternoon with the public meeting in the evenings. The open houses allowed for one-onone discussions and questions while the public meetings were designed to provide an overview of the 

DEIS and the process used in developing and assessing the alternatives. A question-and-answer session 

was held at the end of each presentation. Approximately 600 - 700 people attended the various public 

meetings and open houses. In addition, presentations were made to the Nevada, Placer, and Sierra County 

Boards of Supervisors and several interest groups as requested.

Although a two-month comment period was initially announced, it was expanded for an additional 

month based on public and elected official requests for a total of three months. The comment period 

ended December 26, 2008, but comments were accepted through December 29 due to a Presidential 

Proclamation to close the office on Friday, December 26.

Over 7,000 letters, emails, map packets and other supporting material were received. The Forest 

Service then began the process of reviewing submitted comments and suggestions. This process involved 

sorting and grouping similar comments. Several of the comments questioned some of the data in the 

DEIS. The ID Team then went back to older NEPA documents to verify road and trail status decisions. A 

review of these earlier decisions caused the Forest Service to revise the numbers in the analysis in regard 

to National Forest System roads and trails and unauthorized roads and trails. The IDTeam also reviewed 

the current status of roads and trails across private land and found that some of these did not have valid 

rights-of-ways which was also corrected in the analysis and will be displayed in the Supplemental Draft 

Environmental Impact Statement.

Supplemental Draft Environmental Impact Statement _________

A 45-day comment period will be provided after the release of the Supplemental Draft Environmental 

Impact Statement (SDEIS) in 2010.
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 4: Consultation and Coordination

832 – Tahoe National Forest

Relations with American Indian Tribes ______________________

Throughout the Travel Management Project, comments were solicited from federally recognized and 

unacknowledged tribes, intertribal organizations, and individuals. The following is a summary of the 

communications to date with American Indian Tribes. The communications displayed in Table 4-1 are in 

addition to the regular letters/meetings/email updates for the general public.

Table 4-1. American Indian Tribes summary of communications

Who When

T’si-Akim Maidu, Donald Ryberg; Washoe Tribal Council, Brian Wallace; 

United Auburn Indian Community, Jessica Taverrs; Colfax-Todd Valley Consolidated 

Tribe, Richard Prout; Todd Valley Miwok-Maidu Cultural Foundation, Brigette 

Zellner; Greenville Rancheria, Lorie Jaimes; California Indian Basketweavers 

Association, Sara Greensfelder, and Wadatkuht Band of the Northern Paiutes of the 

Honey Lake Valley, Harold Dixon.

March 15, 2005 (letters, 

e-mails, and phone calls)

United Auburn Indian Community, Yolanda Chavez of Environmental Services April 26, 2007 (phone call)

Ms. Shannon Brawley, Executive Director, California Indian Basketmakers 

Association

April 13, 2007 (letter)

United Auburn Indian Community (UAIC), Yolanda Chavez of Analytical 

Environmental Services 

July 5, 2007 (phone call)

United Auburn Indian Community (UAIC) July 10, 2007 (meeting)

Mike DeSpain, Greenville Rancheria Environmental Coordinator May 4, 2007 (phone call)

Waldo Walker, Washoe Tribe of Nevada and California March 18, 2008 (letter)

Jessica Tavares, United Auburn Indian Community March 18, 2008 (letter)

Lavina Suehead, Colfax Todd Valley Consolidated Tribe March 20, 2008 (letter)

Don Ryberg, T'si-Akim Maidu March 20, 2008 (letter)

Bridget Zellner, Todd Valley Miwok-Maidu Cultural Foundation March 20, 2008 (letter)

Darrel Cruz, Washoe Tribe of Nevada and California May 27, 2008 (phone call)

Darrel Cruz, Washoe Tribe of Nevada and California July 3, 2008

Lorie James and Mike DeSpain, Greenville Rancheria; Don Ryberg, T’si Akim 

Maidu; Waldo Walker, Washoe Tribal Council; United Auburn Indian Community; 

Levina Suehead, Colfax-Todd Valley Consolidated Tribe; Brigette Zellner, Todd 

Valley Miwok-Maidu Cultural Foundation; Harold Dixon, Wadatkauht Band of the 

Northern Paiutes of the Honey Lake Valley.

February 12 , 2009 (letter)
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 4: Consultation and Coordination

Tahoe National Forest – 833

List of Preparers _______________________________________

The following is a list of contributors to this final environmental impact statement. Numerous other 

people have also contributed in many ways to this document.

David Arrasmith: Forest Planner, BS Agricultural Economics & Management, 29 Years with Forest 

Service or other land management agency

John Babin: GIS Coordinator, BS Forest Management, 32 years

Terry Brennan: Professional Engineer, Public Services Staff Officer, BS Civil Engineering, 32 years

Keith Brown: Forest Recreation Planner, BS Natural Resource Econ, MS Recreation Planning, 12 years

Gary Chase: EIS Layout and Publication, AA Forest Technology, 36 years

Joe Chavez: Yuba River Ranger District Public Service Officer, BS Forestry Resources Management, 21 

years 

Jan Cutts: American River District Ranger, BS Anthropology, 18 years

Donna Day: Assistant Forest Archaeologist, BA Anthropology, 38 years 

Alan Doerr: GIS Analyst, BS Forest Science & Ecology, 32 years

Gary Fildes: Forest Fuels Specialist, BS Natural Resources, 44 years

Chris Fischer: American River District Ranger, MS Forest Management, 10 years

Jonathan George: American River Recreation Officer, BS Recreation, Park, and Natural Resource

Management, 6 years.

Kevin McComb: Forest Recreation Officer; BS Earth Science, 20 years

Melissa Hallas: Civil Engineer, BS Biological Systems Engineering, 7 years

Phil Horning: Forest Landscape Architect and Recreation Planner, BLA (Landscape Architecture), 37 

years

Scott Husmann: Forest Road Manager, AS Forestry, 33 years

Susanne Jensen: Truckee Ranger District OHV Specialist, BS Environmental Conservation, 22 years

Vivian Kee: Natural Resources Staff Officer, BS and MS Biological Sciences, 30 years 

Carol Kennedy: Soil Scientist, BS Soil Science, 22 years

Walter Levings: Natural Resource Staff Officer, BS Natural Resource Management, 34 years

Dean Lutz: Truckee Ranger District Asst. Recreation Officer, BS Park Resource Management, 10 years

Rick Maddalena: Truckee District Recreation Officer, BS Forest Management, 37 years 

Jean Masquelier: Yuba River District Ranger, BA Sociology, 31 years

Tina Mark: Forest Biologist, BA Zoology, 27 years

David Michael: Forest Trails and OHV Program Manager, Associate of Science (Forestry), 40 years 

Laurie Perrot: Environmental Coordinator, BS Forestry, 25 years

Bonnie Petitt: Forest Recreation Program Manager, BA Physical Education, BS Forestry, 32 years

Joanne Roubique: Truckee District Ranger, BLA (Landscape Architecture), 35 years

Carrie E. Smith: Archaeologist, BA Anthropology, MA Anthropology, 18 years

Marilyn Tierney: Yuba River District Biologist, BS and MS Biology, 36 years

Jeanne-Pincha-Tulley: Forest Fire Chief, BS Forestry, 30 years
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Chapter 4: Consultation and Coordination

834 – Tahoe National Forest

Kathy Van Zuuk: Ecologist, BS Biology/Chemistry, MS Plant Ecology, 26 years

Karen Walden: NEPA Planner, BS Forest Resources Management, 9 years

Ann Westling: Public Affairs Officer, BA Liberal Arts/Education, MS Environmental Studies, 31 years 

Sam J. Wilbanks: Sierraville District Ranger, BS Natural Resource Management, MF Forest 

Engineering, 31 years

Jeff Wiley: Sierraville Ranger District OHV Program Manager, BS Forest Science, 17 years

Quentin L. Youngblood: Sierraville District Ranger, BS Forest Management, 21 Years
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Index

Tahoe National Forest – 835

Volume 1 Index

Animals

American Marten, 153, 157, 158, 162, 168, 

260, 264, 274, 306, 334, 335, 336, 337, 

338, 339, 340, 341, 342, 344, 345, 346, 

349, 350, 351, 352, 353, 354, 355

Bald Eagle, 158, 168, 365, 366, 369, 371, 

373, 374, 375

Band-tailed pigeon, 162

Black Bear, 156, 157, 162, 173, 175, 176, 

177, 179, 181

Blue Grouse, 253, 254, 257, 260

Brown-headed Cowbirds, 264, 269, 376

California Floater, 159, 162, 508, 517

California Mule Deer, 156, 160, 162, 167, 

168, 171, 198, 199, 200, 201, 202, 203, 

205, 216, 217, 218, 219, 229, 230, 231, 

232, 233, 234, 235, 236, 239

California Red-legged Frog, 159, 162, 

453, 454, 455, 456, 457, 458

California Spotted Owl, 42, 44, 157, 159, 

162, 165, 166, 168, 171, 260, 262, 263, 

268, 273, 274, 275, 276, 277, 278, 279, 

281, 282, 284, 287, 288, 289, 290, 292, 

293, 294, 295, 296, 297, 298, 299, 300, 

301, 302, 303, 304, 305, 306, 307, 308, 

310, 311, 320, 329, 353, 397

California Wolverine, 159, 185, 186, 187, 

188, 189, 190, 191, 192, 193, 195, 197, 

198, 199, 334

Foothill Yellow-legged Frog, 458, 459, 

460, 461, 462, 463, 464, 465, 466, 467, 

468, 470, 471, 472, 473, 475, 476

Golden Eagle, 151, 365

Great Basin Ramshorn Snail, 160, 162, 

508, 509, 510, 511, 512, 513, 515, 517

Great Gray Owl, 159, 162, 260, 363, 364, 

388, 389, 390, 391, 393, 395, 396, 397, 

398, 399

Greater Sandhill Crane, 159, 162, 169, 

363, 399, 400, 401, 402, 403, 405, 406, 

407

Hardhead, 160, 162

Lahontan Cutthroat Trout, 42, 160, 162, 

427, 428, 429, 430, 431, 432, 433, 434, 

435, 436, 437, 438, 439, 440, 441, 442

Lahontan Lake Tui Chub, 160, 162, 442, 

443, 444, 445, 446, 447, 448, 449, 450, 

451, 452, 509

Mountain Quail, 160, 162, 244, 245, 246, 

247, 248, 249, 250, 252

Mountain Yellow-legged Frog, 478, 479, 

480, 481, 482, 483, 484, 485, 486, 487, 

488, 489, 490, 492, 494

Northern Goshawk, 42, 152, 160, 162, 

166, 168, 171, 260, 262, 274, 310, 311, 

312, 313, 315, 316, 318, 321, 322, 323, 

325, 326, 327, 328, 329, 331, 332, 333, 

334

Northwestern Pond Turtle, 161, 162, 495, 

496, 497, 498, 499, 500, 501, 502, 503, 

504, 506

Pacific Fisher, 153, 161, 162, 168, 260, 

264, 274, 334, 335, 336, 337, 338, 339, 

340, 341, 342, 344, 345, 346, 351, 352, 

354, 355, 596

Pallid Bat, 161, 236, 239

Sierra Nevada Red Fox, 161, 162, 168, 

173, 174, 175, 185, 186, 187, 188, 190, 

191, 193, 194, 195, 197, 198, 199, 334

Western Gray Squirrel, 161

Western Red Bat, 161, 162

Wild Turkey, 161, 162, 235, 236, 239

Willow Flycatcher, 161, 162, 363, 364, 

375, 376, 377, 378, 379, 380, 381, 383, 

384, 385, 386, 387, 388, 389, 397

Aquatic Dependent Species, 1, 157, 171

Backpacking, 672, 673, 805, 807, 808, 811, 

813, 814

Best Management Practices, 92, 102, 

114, 115, 122, 441

Bicycling, 672, 673, 805, 807, 808, 811, 

813, 814

Blue Ribbon Coalition, 28, 34, 35, 564

California Air Resources Board, 57, 58, 

59, 62, 67
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Index

836 – Tahoe National Forest

California Wildlife Habitat Relationships, 

168, 175, 186, 187, 188, 192, 193, 239, 

260, 261, 262, 263, 264, 265, 266, 267, 

268, 274, 277, 300, 310, 328, 329, 338, 

339, 340, 342, 344, 345, 346, 349, 351, 

355, 375, 397, 407, 408, 586, 623, 624, 

627

Climate Change, 51, 52

Counties

Nevada, 68, 577, 744, 802, 803

Placer, 64, 68, 354, 532, 595, 742, 747, 

781, 783, 787, 800, 802, 804, 820

Plumas, 354, 824

Sierra, 68, 784, 787, 801, 803, 804

Yuba, 454, 801, 802, 803, 820, 821

Critical Aquatic Refuges, 91, 115, 153, 

354, 388, 399, 406, 416, 427, 456, 457, 

517

Cross-country Skiing, 672, 673, 741, 805, 

807, 808, 813, 814

Cultural Resource Sites, 20

Cumulative Effects, 49, 70, 71, 72, 73, 74, 

76, 77, 78, 79, 90, 99, 107, 108, 109, 110, 

111, 112, 113, 121, 142, 143, 145, 146, 

147, 148, 169, 175, 178, 181, 183, 184, 

193, 196, 197, 219, 224, 227, 229, 239, 

242, 243, 250, 251, 257, 258, 262, 263, 

267, 268, 272, 273, 293, 294, 296, 297, 

299, 301, 302, 303, 304, 305, 325, 326, 

328, 330, 331, 332, 344, 346, 347, 348, 

349, 350, 351, 361, 362, 373, 374, 375, 

383, 384, 385, 386, 387, 395, 396, 397, 

405, 413, 414, 423, 424, 425, 426, 435, 

437, 441, 449, 450, 457, 471, 473, 487, 

488, 490, 503, 511, 512, 517, 530, 531, 

571, 598, 611, 620, 627, 628, 632, 637, 

643, 649, 653, 698, 699, 701, 712, 720, 

732, 735, 749, 751, 753, 754, 755, 757, 

759, 760, 762, 763, 764, 765, 769, 771, 

777, 778, 779, 780, 789, 790, 791, 792, 

793, 794, 795, 796, 826

Cumulative Watershed Effects, 44, 96, 

97, 117, 122, 130

Deer Herds

Blue Canyon Deer Herd, 205, 206, 207, 

208, 210, 211, 212, 213, 214, 215, 216, 

219, 220, 221, 222, 223, 234, 235

Downieville Deer Herd, 205, 206, 208, 

210, 211, 220, 221, 224, 225, 234

Doyle Deer Herd, 200

Loyalton-Truckee Deer Herd, 206, 207, 

208, 209, 210, 211, 220, 221, 222, 227, 

228, 229, 234

Nevada City Deer Herd, 206, 207, 208, 

209, 210, 211, 220, 221, 222, 225, 226, 

227, 234

Donner Lake, 81, 125, 132, 133, 159, 365, 

517

Environmental Justice, 54, 816, 818, 822, 

824, 831

Ethnicity

American Indian, 801, 802, 818, 819, 829

Asian/Pacific Islander, 801, 802, 818, 819

Black Americans, 801

Hispanic, 801, 802, 818, 819, 830

Miwok-Maidu (Native Americans), 829, 

830

Native Americans, 801, 829

Nisenan Maidu (Native Americans), 531

Wadatkuht Band (Native Americans), 

829

Washoe (Native Americans), 830

White, not Hispanic, 801, 802

Granite Chief Wilderness, 595, 670, 674, 

713, 736, 737, 740, 744, 768, 773, 780

Home Range Core Areas, 166, 168, 274, 

275, 277, 289, 290, 292, 294, 297, 298, 

299, 300, 302, 303, 304, 305, 308, 309

Horseback Riding, 672, 673, 805, 807, 

808, 811, 813, 814

Humbug Creek, 125, 132, 133, 419, 466, 

783, 787

Hydrologic Unit Code 7, 81, 82, 99, 122, 

130, 431, 432, 434, 435, 436, 437, 441, 

443, 444, 445, 446, 447, 448, 449, 450, 

460, 461, 462, 463, 464, 465, 468, 469, 

470, 471, 472, 473, 479, 480, 481, 482, 
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Index

Tahoe National Forest – 837

483, 485, 486, 489, 496, 497, 498, 500, 

501, 502, 503, 509, 510, 511, 512

INFRA Database, 4, 5, 729, 734

Inventoried Roadless Areas, 13, 16, 42, 

45, 123, 345, 352, 562, 594, 595, 597, 

651, 652, 653, 654, 655, 656, 657, 670, 

674, 736, 737, 738, 740, 741, 742, 743, 

744, 745, 746, 747, 748, 749, 750, 751, 

752, 753, 754, 755, 756, 757, 758, 759, 

760, 761, 762, 763, 764, 765, 767, 768, 

772, 773, 781, 825

Bald Mountain, 740, 741, 742, 753

Castle Peak, 188, 189, 655, 656, 740, 741, 

742, 753, 754, 768

Duncan Canyon, 740, 742, 743, 754, 755

East Yuba, 653, 655, 656, 740, 743, 755, 

757, 758

Granite Chief, 595, 670, 674, 711, 713, 

736, 737, 740, 744, 759, 768, 770, 773, 

780

Grouse Lakes, 655, 656, 740, 744, 745, 

759, 760, 768

Lakes Basin, 745, 762

Middle Yuba, 125, 126, 129, 130, 137, 138, 

139, 141, 428, 431, 432, 433, 441, 465, 

472, 499, 500, 740, 745, 746, 762, 763

North Fork American River, 130, 137, 

138, 139, 141, 465, 483, 498, 499, 500, 

670, 740, 746, 747, 763, 768, 775, 777, 

778, 780

West Yuba, 16, 653, 654, 655, 656, 740, 

748, 750, 764, 765, 767

Kanaka Creek, 125, 132, 133, 465

Lake Tahoe, 6, 123, 160, 259, 337, 442, 

443, 508, 509, 511, 517, 744, 784

Management Indicator Species, 151, 

153, 158, 160, 161, 168, 175, 199, 232, 

233, 235, 239, 241, 243, 244, 246, 247, 

248, 252, 253, 255, 258, 259, 274, 306, 

334, 352, 353, 355, 358, 362, 363, 407, 

409, 410, 415, 418, 425

Mitigations, 19

Mixed use, 8, 9, 11, 15, 16, 17, 18, 23, 24, 

26, 28, 30, 32, 39, 69, 71, 72, 73, 75, 92, 

108, 109, 110, 111, 112, 116, 142, 144, 

145, 147, 148, 557, 599, 608, 619, 625, 

631, 634, 641, 652, 665, 666, 675, 676, 

679, 680, 682, 685, 686, 688, 689, 690, 

693, 695, 697, 700, 714, 723, 725, 728, 

730, 731, 732, 733, 750, 752, 758, 761, 

767, 772, 778, 779, 780, 793, 794, 795, 

797

Monitoring, 19

Motor Vehicle Use Map, 2, 3, 8, 9, 19, 20, 

21, 22, 24, 27, 28, 30, 32, 48, 50, 150, 

552, 677, 681, 683, 687, 691, 696, 733, 

734, 830

Motorized Mixed Use, 16

National Visitor Use Monitoring Report, 

660, 661, 670, 672, 673, 711, 713, 805, 

806, 810, 812

National Wild and Scenic River

Canyon Creek, 483, 488, 737, 765, 774, 

775, 778

North Fork of the American River, 746, 

774, 775, 777

North Yuba River, 127, 137, 138, 139, 141, 

454, 464, 466, 483, 484, 737, 774, 775, 

778

Sagehen Creek, 428, 431, 432, 434, 484, 

509, 737, 774, 775, 776, 779

South Yuba River, 137, 138, 139, 141, 

467, 483, 484, 498, 499, 737, 774, 776, 

779, 780

Naturally Occurring Asbestos, 44, 58, 65, 

66, 67, 74, 75, 76, 77, 78, 79

Notice of Intent, 9, 10, 11, 26, 28, 31, 35, 

42, 112, 148, 562, 564, 570, 695, 706, 

719, 824, 827

Old Forest Emphasis Areas, 44, 187, 193, 

260, 262, 269, 270, 271, 272, 273, 274, 

300, 328, 338, 339, 340, 342, 344, 345, 

346, 348, 355

Onion Creek Experimental Forest, 773

Ozone, 61, 64, 68

Pacific Crest National Scenic Trail, 325, 

671, 677, 687, 691, 696, 741, 743, 745

Preferred Alternative (Alternative 6), 16, 

29, 37, 53, 111, 146, 198, 352, 398, 567, 

690, 705, 719
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Index

838 – Tahoe National Forest

Proposed Action (Alternative 7), 1, 2, 8, 

9, 10, 11, 12, 13, 15, 23, 26, 28, 31, 35, 

38, 42, 112, 148, 151, 169, 170, 178, 179, 

218, 238, 242, 249, 256, 266, 271, 324, 

343, 360, 372, 382, 383, 388, 394, 397, 

399, 404, 407, 412, 416, 425, 437, 438, 

440, 450, 451, 473, 474, 475, 476, 

477,490, 491, 492, 493, 494, 503, 504, 

505, 506, 507, 512, 513, 514, 515, 516, 

557, 562, 564, 570, 574, 658, 676, 682, 

695, 706, 719, 827

Protected Activity Centers, 42, 44, 166, 

168, 262, 274, 275, 276, 277, 278, 279, 

281, 282, 283, 284, 285, 286, 287, 288, 

293, 294, 295, 296, 297, 299, 300, 301, 

302, 305, 308, 309, 310, 311, 312, 313, 

314, 315, 316, 318, 320, 321, 322, 323, 

324, 325, 326, 327, 328, 329, 330, 331, 

332, 333, 334, 389, 398, 519

Purpose and Need, 15

Rare Plants, 20

Regulations

California Vehicle Code, 16, 33, 725, 728, 

730, 731, 785

California Water Code, 114

Clean Air Act, 10, 54, 57

Clean Water Act, 10, 54, 83, 114, 124, 125

Comprehensive Environmental

Response, Compensation, and 

Liability Act, 85

Endangered Species Act, 10, 54, 84, 151, 

574, 628, 629

Federal Highway Safety Act, 725, 728, 

730, 731

Forest and Rangeland Renewable 

Resources Planning Act, 10, 55, 84, 530

Herger-Feinstein Quincy Library Group 

Forest Recovery Act, 257

Multiple Use and Sustained Yield Act, 10

National Environmental Policy Act, 1, 4, 

5, 10, 12, 19, 21, 33, 35, 36, 42, 49, 52, 53,

84, 91, 92, 94, 105, 130, 152, 178, 326, 

328, 331, 347, 348, 349, 387, 396, 420, 

421, 425, 460, 461, 464, 474, 476, 480, 

481, 491, 492, 493, 497, 504, 506, 581, 

597, 729, 828

National Forest Management Act, 10, 55, 

84, 90, 91, 151, 574, 658, 674, 708, 724

National Historic Preservation Act, 10, 

53, 526, 527, 528, 529, 530, 531, 541, 543,

553, 738

Porter-Cologne Water-Quality Act, 114

Safe Drinking Water Act, 85

Secure Rural Schools and Community 

Self-Determination Act, 821, 823

Research Natural Areas, 594, 595, 598, 

660, 670, 736, 737, 739, 741, 780

Babbitt Peak, 595, 780

Lyon Peak/Needle Lake, 595, 780

Sugar Pine Point, 211, 595, 780

Reservoirs

Boca, 16, 25, 31, 38, 42, 134, 142, 143, 

145, 146, 147, 148, 160, 172, 173, 174, 

191, 195, 217, 339, 366, 367, 368, 369, 

373, 378, 389, 400, 406, 417, 418, 434, 

442, 443, 444, 445, 446, 449, 450, 451, 

462, 478, 483, 508, 509, 515, 535, 540, 

545, 553, 557, 558,559, 568, 600, 607, 

615, 648, 650, 678, 692, 693, 716, 719, 

829

Bullards Bar, 366, 454, 455, 463, 499, 500, 

784

French Meadows, 650, 742

Prosser, 16, 25, 31, 38, 42, 134, 142, 143, 

145, 146, 147, 148, 160, 172, 173, 174, 

191, 195, 217, 339, 366, 367, 368, 369, 

373, 378, 389, 400, 417, 418, 427, 431, 

432, 433, 434, 442, 443, 444, 445, 446, 

449, 450, 451, 462, 478, 484, 508, 509, 

515, 536, 540, 546,鿜547, 554, 557, 558, 

559, 568, 600, 607, 615, 650, 678, 682, 

684, 688, 692, 693, 697, 716, 719, 829

Stampede, 16, 25, 31, 38, 42, 125, 133, 

134, 142, 143, 145, 146, 147, 148, 160, 

172, 173, 174, 191, 195, 217, 339, 366, 

367, 368, 369, 373, 378, 400, 401, 403, 

404, 405, 417, 418, 431, 432, 434, 442, 

443, 444, 445, 446, 449, 450, 451, 462, 

478, 508, 509, 515, 536,鿜537, 540, 547, 

548, 554, 555, 557, 558, 559, 560, 563, 

568, 600, 607, 615, 650, 678, 692, 693, 

716, 719, 829
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Index

Tahoe National Forest – 839

Riparian, 1, 91, 114, 115, 118, 125, 130, 

136, 153, 161, 163, 164, 171, 363, 364, 

387, 388, 398, 406, 409, 410, 411, 416, 

417, 419, 421, 422, 424, 427, 429, 430, 

431, 432, 434, 435, 441, 443, 444, 446, 

450, 456, 457, 459, 460, 468, 469, 471, 

472, 478, 479, 480, 485, 486, 495, 496, 

501, 508, 509, 512, 518, 519, 575, 577, 

581, 583, 584, 603

Riparian Conservation Areas, 44, 91, 

115, 117, 118, 119, 121, 125, 126, 130, 

135, 136, 137, 138, 141, 142, 143, 144, 

145, 146, 147, 148, 149, 153, 166, 171, 

274, 275, 277, 289, 302, 303, 304, 305, 

354, 363, 387, 388, 398, 399, 406, 409, 

416, 417, 418, 419, 420, 421, 422, 423, 

424, 425, 426, 427, 429, 430, 431, 432, 

434, 435, 436, 438, 439, 440, 441, 442, 

443, 444, 445, 446, 447, 448, 450, 451, 

452, 456, 457, 459, 460, 461, 462, 463, 

465, 466, 467, 468, 469, 471, 472, 473, 

474, 475, 476, 477, 478, 479, 480, 481, 

485, 486, 489, 491, 492, 493, 494, 495, 

496, 497, 498, 500, 501, 503, 505, 506, 

507, 508, 509, 510, 511, 512, 513, 514, 

515, 516, 517, 519, 610

Riparian Conservation Objectives, 91, 

114, 115, 125, 130, 153, 354, 388, 399, 

406, 407, 416, 441, 517, 518, 575

River Basins

American, 126, 130, 139

Bear, 126, 129, 139, 142

Truckee, 123, 127, 129, 135, 136, 139, 142, 

427, 441

Yuba, 126, 130, 139

Rivers

American, 124, 126, 130, 137, 138, 139, 

141, 159, 169, 243, 466, 495, 498, 500, 

532, 636, 672, 740, 742, 744, 746, 747, 

763, 764, 768

Bear, 123, 126, 129, 137, 138, 139, 141, 

142, 637, 822

Feather, 122, 123, 126, 129, 137, 138, 139, 

141, 389, 454, 532

Truckee, 123, 124, 125, 126, 127, 129, 133, 

134, 135, 136, 137, 138, 139, 141, 142, 

160, 383, 419, 427, 428, 431, 432, 433, 

435, 441, 442, 450, 481, 483, 484, 508, 

509, 511, 517, 648, 699

Yuba, 122, 126, 130, 137, 139, 141, 159, 

161, 169, 243, 304, 427, 433, 454, 467, 

495, 500, 503, 671, 743, 744, 745, 746, 

774, 780, 817, 818, 819, 820, 823, 824

Roadless Area Review and Evaluation, 

653, 736

Sagehen Experimental Forest, 773, 774

Sensitive Species, 19

Sierra Nevada Forest Plan Amendment, 

64, 68, 91, 115, 116, 118, 152, 158, 187, 

188, 197, 199, 229, 243, 250, 257, 260, 

274, 277, 301, 310, 311, 329, 333, 337, 

340, 349, 352, 353, 354, 355, 364, 376, 

387, 389, 397, 398, 405, 406, 413, 416, 

424, 428, 441, 455, 472, 488, 517, 575, 

576, 578, 581, 586, 587, 626, 627, 632, 

658, 801, 802, 803

Sierra Pacific Industries, 4, 185, 187, 188, 

744, 782, 783, 786

Significant Issues, 15

Snags, 17, 160, 161, 162, 163, 164, 168, 

174, 175, 186, 187, 188, 190, 194, 260, 

262, 263, 269, 275, 276, 301, 334, 335, 

337, 338, 352, 355, 356, 357, 358, 361, 

362, 363, 373, 389

Special Aquatic Features

Aspen Clones, 613

Bogs, 478, 575

Fens, 117, 575, 577, 582, 584, 604, 609, 

611, 612, 776

Marshes, 117, 161, 456, 457

Seeps, 86, 88, 581, 582, 583, 584, 585, 

593, 594, 605, 609, 611, 616

Vernal Pools, 583, 605

Wet Meadows, 159

Wetlands, 54, 86, 115, 119, 125, 152, 153, 

155, 157, 159, 354, 364, 376, 387, 388, 

398, 399, 400, 406, 407, 416, 443, 454, 

456, 457, 503, 518, 575, 581, 582, 584, 

592, 605, 611, 612, 637, 738

Special Interest Areas, 82, 86, 87, 594, 

595, 598, 736, 737, 740, 780
Motorized Travel Management Supplemental Draft Environmental Impact Statement – February 2010

Index

840 – Tahoe National Forest

Glacier Meadow Geologic area, 595

Grouse Falls Scenic area, 595

Meadow Lake Cultural area, 595

Placer County Big Tree Grove Botanical 

area, 595

Sagehen Headwaters, 595, 781

Squaw Creek, 124, 125, 133, 134, 419, 

484

Tahoe National Forest Land and 

Resource Management Plan, 22, 24, 

28, 30, 33, 35, 48, 91, 92, 98, 108, 111, 

112, 115, 151, 154, 175, 197, 199, 200, 

204, 205, 229, 233, 234, 235, 240, 243, 

244, 250, 252, 257, 259, 274, 306, 310, 

333, 345, 353, 354, 355, 361, 362, 364, 

387, 388, 389, 398, 399, 406, 415, 416, 

424,425, 517, 518, 574, 608, 645, 658, 

659, 660, 661, 662, 674, 675, 676, 677, 

680, 682, 686, 690, 695, 698, 701, 707, 

708, 710, 711, 714, 724, 785, 792

Threatened, Endangered, Sensitive, and 

Proposed, 168, 575, 576, 595

Threshold of Concern, 130

Travel Management Project, 58, 86, 152, 

154, 199, 233, 234, 235, 244, 251, 252, 

259, 260, 274, 306, 307, 352, 353, 354, 

357, 362, 363, 375, 387, 388, 389, 398, 

399, 407, 415, 416, 426, 428, 455, 517, 

518, 519, 829

Travel Management Rule, 2, 6, 7, 10, 22, 

33, 50, 51, 552, 658, 674, 707, 708, 724, 

726, 828

Truckee River Basin Recovery 

Implementation Team, 427

Upper Truckee River, 427

Vegetation Treatments

Clearcutting, 119, 294, 332, 397, 626

Hazard Tree Removal, 231, 251, 258, 

337, 356, 357, 361, 414, 455

Shelterwood, 294, 332, 397

Thinning, 99, 184, 230, 231, 243, 250, 251, 

257, 258, 294, 332, 361, 373, 397, 414, 

520

Vehicles

4-wheel Drive, 7, 12, 17, 29, 33, 41, 155, 

181, 184, 197, 229, 243, 250, 257, 424, 

667, 668, 669, 671, 677, 678, 684, 688, 

690, 692, 696, 729, 740

All Terrain Vehicle, 1, 5, 7, 12, 25, 27, 29, 

31, 32, 33, 41, 58, 62, 118, 155, 181, 184, 

197, 229, 243, 250, 257, 284, 424, 661, 

667, 668, 669, 670, 671, 677, 684, 688, 

689, 690, 692, 694, 696, 726, 729, 733, 

785, 829

Motorcycles, 1, 5, 7, 12, 22, 25, 27, 29, 31, 

32, 33, 41, 48, 58, 62, 121, 155, 167, 172, 

181, 184, 197, 229, 243, 250, 257, 275, 

276, 284, 285, 300, 424, 433, 528, 543, 

590, 598, 601, 627, 661, 667, 668, 669, 

670, 671, 677, 684, 685, 688, 689, 690, 

692, 694, 696, 698, 726, 729, 732, 733, 

740, 743, 747, 748, 756, 764, 765, 768, 

783, 784, 785, 787, 829

Off Highway Vehicle, 1, 2, 4, 20, 33, 34, 

35, 36, 50, 54, 58, 94, 100, 102, 114, 117, 

119, 121, 131, 133, 134, 153, 176, 184, 

201, 204, 230, 234, 250, 257, 296, 298, 

299, 337, 395, 405, 413, 518, 531, 637, 

658, 659, 660, 664, 670, 671, 672, 673, 

676, 678, 679, 680, 682, 683,鿜684, 685, 

686, 688, 689, 691, 694, 695, 697, 698, 

716, 719, 725, 728, 741, 743, 744, 745, 

747, 748, 770, 773, 774, 780, 782, 783, 

787, 793, 794, 795, 796, 805, 807, 808, 

812, 814, 815

Over Snow Vehicle, 336, 337, 406, 672, 

673, 741, 805, 807, 808, 812, 814, 815

Sports Utility Vehicle, 1, 7, 670, 693

Visual Quality Objectives, 708, 709, 710, 

711, 712, 713, 714, 716, 717, 718, 719, 

720, 721, 723

Wildland/Urban Interface, 522, 524, 785, 

792