United States Department of Agriculture

Tahoe National Forest 

Over-snow Vehicle Use 

Designation

Draft Environmental Impact Statement

Volume I. Chapters 1 through 4 and References

Forest 

Service

Tahoe

National Forest

April 2018
In accordance with Federal civil rights law and U.S. Department of Agriculture (USDA) civil rights 

regulations and policies, the USDA, its Agencies, offices, and employees, and institutions participating 

in or administering USDA programs are prohibited from discriminating based on race, color, national 

origin, religion, sex, gender identity (including gender expression), sexual orientation, disability, age, 

marital status, family/parental status, income derived from a public assistance program, political beliefs, 

or reprisal or retaliation for prior civil rights activity, in any program or activity conducted or funded by 

USDA (not all bases apply to all programs). Remedies and complaint filing deadlines vary by program 

or incident. 

Persons with disabilities who require alternative means of communication for program information (e.g., 

Braille, large print, audiotape, American Sign Language, etc.) should contact the responsible Agency or 

USDA’s TARGET Center at (202) 720-2600 (voice and TTY) or contact USDA through the Federal 

Relay Service at (800) 877-8339. Additionally, program information may be made available in 

languages other than English. 

To file a program discrimination complaint, complete the USDA Program Discrimination Complaint 

Form, AD-3027, found online at http://www.ascr.usda.gov/complaint_filing_cust.html and at any USDA 

office or write a letter addressed to USDA and provide in the letter all of the information requested in the 

form. To request a copy of the complaint form, call (866) 632-9992. Submit your completed form or 

letter to USDA by: (1) mail: U.S. Department of Agriculture, Office of the Assistant Secretary for Civil 

Rights, 1400 Independence Avenue, SW, Washington, D.C. 20250-9410; (2) fax: (202) 690-7442; or (3) 

email: program.intake@usda.gov. 

USDA is an equal opportunity provider, employer and lender.
Draft Environmental Impact Statement 

Tahoe National Forest

iii

Over-snow Vehicle Use Designation

Draft Environmental Impact Statement

Tahoe National Forest

Lead Agency: USDA Forest Service

Responsible Official: Eli Ilano

Forest Supervisor

Tahoe National Forest

631 Coyote Street

Nevada City, CA 95959

For further information, contact:

Joe Chavez, 

Forest Trails and Recreation Specialist

631 Coyote Street

Nevada City, CA 95959

(530) 478-6158

Abstract: The Forest Service proposes to designate snow trails and areas for public over-snow 

vehicle (OSV) use on the Tahoe National Forest. These designations would occur on National Forest 

System snow trails and areas on National Forest System lands within the Tahoe National Forest. The 

Forest Service would also identify snow trails where grooming for public OSV use would occur 

within the Tahoe National Forest. An amendment to the Tahoe National Forest Land and Resource 

Management Plan (LRMP 1990) is needed contemporaneously with the approval of a decision 

regarding public OSV use to: (1) appropriately place planning, analysis, and decision-making for 

OSV use at the project level and (2) ensure this Project is consistent with the LRMP as amended (36 

CFR 219.15(c)(4)).

Consistent with the Forest Service’s Travel Management Regulations at 36 CFR Part 212 Subpart C, 

trails and areas designated for public over-snow vehicle use would be displayed on a publicly 

available over-snow vehicle use map (OSVUM). Public OSV use that is inconsistent with the 

OSVUM would be prohibited under Federal regulations at 36 CFR §261.14.

This draft environmental impact statement (DEIS) compares environmental effects of implementing 

five alternatives, including (1) no action-continuation of current management; (2) the Proposed 

Action, as modified; and three other action alternatives developed in response to issues, and discloses 

their environmental impacts.

A Notice of Intent to prepare an environmental impact statement (EIS) was published in the Federal 

Register on February 23, 2015. We prepared this draft EIS using public comments received during the 

scoping period, multiple interdisciplinary team discussions, and coordination with project 

stakeholders, literature review, and resource analyses.
Over-snow Vehicle Use Designation 

Tahoe National Forest

iv

We encourage your review of this document. It is important that reviewers provide their comments at 

such times and in such a way that they are useful to the Forest Service’s preparation of the final EIS. 

Therefore, comments should be provided prior to the close of the comment period and should clearly 

articulate the reviewer’s concerns and contentions. Comments must be received by the Forest Service 

or postmarked by the Postal Service within 45 days from the date of the Notice of Availability in the 

Federal Register. Failing to submit timely and specific comments can affect a reviewer’s ability to 

participate in subsequent administrative review or judicial review. Comments received in response to 

this solicitation, including names and addresses of those who comment, will be part of the public 

record for this proposed action. Comments submitted anonymously will be accepted and considered; 

however, anonymous comments will not provide the respondent with standing to participate in 

subsequent administrative review or judicial review.

Once the final EIS is prepared, it and the associated draft decision document (Record of Decision) are 

subject to the pre-decisional administrative review process (objection process) pursuant to 36 CFR 

218, subparts A and B. Objections will only be accepted from those who have previously submitted 

specific written comments regarding this proposed project during scoping or other designated 

opportunity for public comment in accordance with 36 CFR 218.5(a) and 219.53. Issues raised in 

objections must be based on previously submitted, timely, specific written comments regarding this 

proposed project unless based on new information arising after the designated comment opportunities.

Send comments to: Joe Chavez, on behalf of Eli Ilano, Forest Supervisor, Tahoe National Forest, 631 

Coyote Street, Nevada City, CA 95959; (530) 478-6158. Comments may also be sent via facsimile to 

530-478-6109, submitted on the project website at 

http://www.fs.fed.us/nepa/nepa_project_exp.php?project=45914, or sent via email to 

tahoe_nf_comments@fs.fed.us, with the email’s subject line, “Comments on Tahoe OSV 

Designation.” The publication date of the Notice of Availability in the Federal Register is the 

exclusive means for calculating the time to submit written comments on a proposed project or activity 

that is analyzed and documented in a draft EIS (36 CFR 218.24(c)(2)).
Draft Environmental Impact Statement – Volume I

Summary

Tahoe National Forest

v

Summary of the Draft Environmental Impact 

Statement 

Purpose and Need

One purpose of this Project is to establish designated areas and trails for OSV use on the Tahoe 

National Forest to: provide access, ensure that public OSV use occurs when there is adequate snow, 

promote the safety of all users, enhance public enjoyment, minimize impacts to natural and cultural 

resources, and minimize conflicts among the various uses of National Forest System lands.

There is a need to provide a manageable, designated OSV system of trails and areas within the Tahoe 

National Forest that is consistent with, and achieves the purposes of, the Forest Service Travel 

Management Rule at 36 CFR Part 212. This action responds to this need.

The Tahoe National Forest Land and Resource Management Plan (LRMP 1990) contains 

management area-specific standards and guidelines pertaining to public OSV use. The existing 

system of OSV trails and areas on the Tahoe National Forest is based on the LRMP’s standards and 

guidelines. Proposed changes to the existing system of OSV trails and areas have been identified, 

based on internal and public input and the Travel Management Rule’s criteria for designating roads, 

trails, and areas at 36 CFR 212.55. These changes would address needs for protecting natural 

resources, improving access for OSV users, improving quiet winter recreation opportunities, and 

ensuring consistency with LRMP management direction. Travel management decisions (including 

designating OSV areas and trails) under the 2012 Forest Service Planning Rule (36 CFR 219) are not 

forest plan decisions, but rather project-level decisions that require site-specific planning, public 

involvement, environmental analysis, and decision making (36 CFR 219.2(b)(1) and (2); Forest 

Service Handbook (FSH) 1909.12, Section 23.23a). An amendment to the Tahoe National Forest 

Land and Resource Management Plan (LRMP 1990) is needed contemporaneously with the approval 

of a decision regarding public OSV use to: (1) appropriately place planning, analysis, and decisionmaking for OSV use at the project level and (2) ensure this Project is consistent with the LRMP as 

amended (36 CFR 219.15(c)(4)).

A second purpose of this project is to comply with the Settlement Agreement between the Forest 

Service and Snowlands Network et al., by identifying those designated National Forest System snow 

trails where grooming for public OSV use would occur and analyzing the effects of the grooming 

program. Under the terms of the Settlement Agreement, the Forest Service is required to complete the 

appropriate NEPA analysis to identify snow trails available for grooming on the Tahoe National 

Forest. 

This action identifies snow trails available for grooming and addresses the need to provide a high 

quality OSV trail system on the Tahoe National Forest that is smooth and stable for the rider and 

designed so the novice rider can use these trails without difficulty.

Modified Proposed Action

The proposed action has been modified based on public comments received during the scoping 

period, and multiple interdisciplinary team discussions. These modifications are described in chapter 

2 of this analysis. Figure 3, located in the map package, displays a map of the proposed action.

The Forest Service proposes to designate areas and trails on National Forest System (NFS) land for 

public over-snow vehicle (OSV) use. These designations would be consistent with the requirements 

of Subpart C of the Forest Service’s Travel Management Regulation at 36 Code of Federal 
Over-snow Vehicle Use Designation 

Tahoe National Forest

vi

Regulations (CFR) Part 212. The Forest Service would also designate trails to be groomed for public 

OSV use under the Tahoe National Forest OSV trail grooming program.

The Forest Service proposes the following actions on the Tahoe National Forest: 

• Approximately 406,895 acres of National Forest System lands are designated for public crosscountry OSV use, generally above 5,000 feet elevation. OSV use designations for the affected 

management areas in the existing Forest Plan (Appendix B) would be amended to accommodate 

the proposed OSV use designation changes under alternative 2.

• Public OSV use would not be designated in a 1-acre area near Robinson Flat to protect historic 

structures.

• Individual parcels of National Forest System lands currently under long-term special use permits 

for Royal Gorge Cross Country Ski Area, Tahoe Donner Cross Country Ski Area, Boreal Ski 

Area, Donner Ski Ranch Ski Area, Sugar Bowl Ski Area, Alpine Meadows Ski Area and Squaw 

Valley Ski Area would not be designated for public OSV use.

• Implement forestwide snow depth requirements for public OSV use by:

♦ Allowing public, cross-country OSV use in designated OSV areas only when there is 

adequate snow depth to avoid damage to natural and cultural resources. To avoid damaging 

resources, a minimum of 12 inches of un-compacted snow is typically needed. On 

designated OSV trails with underlying roads, a minimum of 6 inches is typically needed to 

avoid damage to the underlying road surface; and

♦ Follow California State Parks’ Off-Highway Motor Vehicle Recreation Division snow 

depth standards for grooming, currently 12 to 18 inches of snow.

• Class 1 OSVs are allowed on all designated OSV trails and areas. Class 2 OSVs are only allowed 

on designated OSV trails available for grooming. Class of vehicle definitions can be found on 

page 2.

• Approximately 237 miles of designated OSV trails are available for grooming. Approximately 18 

miles of marked, ungroomed trails are located within areas designated for cross-country OSV use. 

Approximately 70 miles of designated OSV trails are not available for grooming. 

• There would be 22 designated OSV crossings of the Pacific Crest National Scenic Trail (PCT). 

In all cases, OSVs crossing the PCT would do so at 90 degrees to minimize the time and 

distance needed to cross the Trail. The 22 designated OSV crossings of the PCT would be as 

follows:

• Thirteen designated crossings would utilize roads identified on the Tahoe National 

Forest’s Motor Vehicle Use Map and would be the width of the road (approximately 

14 feet). In one instance, the current alignment of the PCT overlays the Pass Creek 

Loop OSV Trail on Forest Service Road 70 for approximately 700 feet.

• Nine proposed OSV crossings of the PCT would range in width up to 0.25 miles. 

These crossings are located in areas where OSV use is designated on either side of 

the PCT. OSV users would need a way to get across the Trail as OSV use along the 

PCT is prohibited by the National System Trails System Act, P.L 90-543, Section 

7(c). Some of these proposed OSV crossings are wider than the width of a road 

because they are located in areas where snow conditions are highly variable during 

the course of a winter, for example areas prone to wind loading of snow and 
Draft Environmental Impact Statement – Volume I

Summary

Tahoe National Forest

vii

formation of cornices. These wider crossings give OSV users options to select a safe 

crossing of the Trail under constantly changing, variable snow loading conditions.

Significant Issues

Internal and external scoping identified the following significant issues and these issues were used to 

develop the action alternatives. The significant issues include the following: 

Table S-1. Significant issues 

Issue Topic Cause and Effect 

Quality Recreational 

Experience

Public OSV use and grooming for public OSV use could impact the overall 

quality of the experience of recreationists seeking a quieter, non-motorized 

experience.

Designating areas and trails for OSV use has the potential to change recreation 

settings and opportunities by enhancing opportunities for motorized winter users 

in some areas and limiting those opportunities in other areas.

Noise OSV use and grooming OSV trails could generate anthropogenic noise and 

increase noise levels in the short term above ambient levels. This may adversely 

impact wildlife species that are sensitive to this sort of disturbance, as well as the 

experience of the recreational user who values solitude and quiet recreational 

opportunities.

Air Quality OSV use and grooming OSV trails may add exhaust and pollutants to the air. 

This could degrade the quality of the air and possibly impact recreational users, 

wildlife, and sensitive areas.

Water and Soil Resources OSV use may result in ground disturbance and snow compaction, and this could

directly, indirectly and/or cumulatively adversely impact soil and water resources 

through soil compaction, erosion, and displacement.

Terrestrial Wildlife OSV use and grooming trails for public OSV usemay directly, indirectly, and 

cumulatively impact terrestrial wildlife through injury, mortality, or disturbance to 

individuals (e.g., increased noise and human presence resulting in a loss of 

breeding and/or feeding) and indirect and/or cumulative impacts to wildlife 

habitats (e.g., snow compaction in or near denning sites).

OSVs, when operating cross-country instead of on designated trails, could affect 

wildlife species by compacting snow in areas of inadequate snow cover and 

disturbing subnivean (i.e., the zone in and under the snow) habitat for small 

mammals.

Aquatic Wildlife Public OSV use and grooming for public OSV use could impact fish and 

amphibian populations and habitat in the project area through: (1) direct 

disturbance to species when OSV use occurs in wet meadows, streams, lakes, 

and/or other sensitive habitats; (2) indirectly through generation of exhaust and 

associated pollutants in or near sensitive habitat, which can degrade water 

quality; (3) indirectly through release of fuel or other pollutants during refueling 

and proximity to sensitive habitats, which can degrade water quality; and 

(4) indirectly through increased soil erosion in marginal snow depth areas.

Alternatives Considered in Detail

The Tahoe National Forest developed five alternatives: No Action, the Modified Proposed Action, and 

three additional action alternatives generated in response to the significant issues listed above. The 

five alternatives considered in detail for this analysis are listed in table S-2. Complete details of the 

alternatives are found in chapter 2 of this document. Mitigations and monitoring procedures are in 

Appendix E (Mitigations for Designated Areas), F (Mitigations for Designated Trails), and G

(General Monitoring Procedures), respectively.
Over-snow Vehicle Use Designation 

Tahoe National Forest

viii

Table S-2. Summary of alternatives considered in detail 

Alternative Description of Alternative

1 Continue Current Management

• 636,002 acres of NFS lands are designated for cross-country OSV use

• 265 miles of trails for OSV use

o 217 miles of designated trails are available for grooming for OSV use

o 41 miles of trails marked, ungroomed for OSV use within OSV Use Areas

o 7 miles of designated OSV trails are not available for grooming

• 1,218 acres of NFS land designated for OSV use from January 1 through September 

14

• No designated crossings on the PCT

• No established minimum snow depth for public OSV cross-country or trail use

2 Modified Proposed Action

• 406,895 acres of NFS lands are designated for OSV use, generally above 5,000 feet 

elevation

• 325 miles of trails for OSV use

o 237 miles of designated trails are available for grooming for OSV use

o 14 miles of trails marked, ungroomed for OSV use within OSV Use Areas

o 70 miles of designated trails not available for grooming

• 22 designated crossings on the PCT

• Adequate snow depth to prevent impacts to surface and subsurface resources

(generally 12 inches for public OSV cross-country use and 6 inches for trail use)

• Follow OHMVR snow depth for grooming, currently 12 to 18 inches of snow

3 Addresses non-motorized quality recreational experience

• 275,972 acres of NFS lands are designated for cross-country OSV use

• 280 miles of trails for OSV use

o 217 miles of designated trails are available for grooming for OSV use

o 38 miles of trails marked, ungroomed for OSV use within OSV Use Areas

o 25 miles of designated trails not available for grooming

• 1,408 acres of NFS land designated for OSV use from January 1 through September 

14

• 3 designated crossings on the PCT

• Minimum snow depth of 18 inches for public OSV cross-country use and 18 inches for 

trail use

• Groom designated OSV trails when there are 18 inches or more of snow.

4 Addresses motorized quality recreational experience

• 641,105 acres of NFS lands are designated for cross-country OSV use

• 287 miles of trails for OSV use

o 260 miles of designated trails are available for grooming for OSV use

o 22 miles of trails marked, ungroomed for OSV use within OSV Use Areas

o 5 miles of designated trails not available for grooming

• 1,218 acres of NFS land designated for OSV use from January 1 through September 

14

• 21 designated crossings on the PCT

• Minimum snow depth of 12 inches for public OSV cross-country use and 6 inches for 

trail use

• Groom designated OSV trails when there are 12 inches or more of snow.
Draft Environmental Impact Statement – Volume I

Summary

Tahoe National Forest

ix

Alternative Description of Alternative

5 Emphasizes protections for wildlife/natural resources and non-motorized opportunities

• 300,146 acres of NFS land open to cross-country OSV use

• 257 miles of trails for OSV use

o 215 miles of designated trails are available for grooming for OSV use

o 25 miles of trails marked, ungroomed for OSV use within OSV Use Areas

o 17 miles of designated trails not available for grooming

• OSV use would be limited to designated OSV trails within 1 mile of existing OSV 

trailheads.

• OSV use would not be designated in areas within the USFS Scenery Management 

System definition of Foreground for the Pacific Crest Trail. 

• 10 designated crossings on the PCT

• Minimum snow depth of 24 inches for public OSV cross-country use and 24 inches for 

trail use

• Follow OHMVR snow depth for grooming, currently 12 to 18 inches of snow
Over-snow Vehicle Use Designation 

Tahoe National Forest

x

Summary of Environmental Impacts

Table S-3 Summary of environmental effects

Indicators by 

Resource Measures Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Recreation Motorized Opportunities – cross-country

Indicator: 

Opportunities for 

motorized winter 

uses

Size of areas 

(acres) designated 

for OSV use; 

percent change 

from current 

management

638,002 acres 

designated for OSV 

use

406,895 acres 

designated for OSV 

use, a 36 percent 

decrease from 

current 

management

275,972 acres 

designated for OSV 

use, a 57 percent 

decrease from 

current 

management

641,105 acres 

designated for OSV 

use, a 0.5 percent 

increase from 

current 

management

300,146 acres 

designated for OSV 

use, a 53 percent 

decrease from 

current 

management

Indicator: Quality of 

OSV opportunities

Percent of acres 

designated for OSV 

use in high to 

moderate 

assumption 

category

33 percent of acres 

designated for OSV 

use provide high 

quality OSV 

opportunities, 

approximately 

212,857 acres

47 percent of acres 

designated for OSV 

use provide high 

quality OSV 

opportunities, 

approximately 

191,311 acres

58 percent of acres 

designated for OSV 

use provide high 

quality OSV 

opportunities, 

approximately 

161,919 acres

33 percent of acres 

designated for OSV 

use provide high 

quality OSV 

opportunities, 

approximately 

212,873 acres

48 percent of acres 

designated for OSV 

use provide high 

quality OSV 

opportunities, 

approximately 

145,420 acres

Recreation Motorized Opportunities – designated snow trails available for grooming and ungroomed

Indicator: OSV trail 

designations

Length (miles) of 

designated OSV 

trails available for 

grooming/Length 

(miles) of marked 

snow trails 

(ungroomed)

217 miles available 

for grooming

41 miles marked, 

ungroomed

237 miles available 

for grooming

14 miles marked, 

ungroomed

217 miles available 

for grooming

38 miles marked, 

ungroomed

259 miles available 

for grooming

22 miles marked, 

ungroomed

215 miles available 

for grooming

25 miles marked, 

ungroomed
Draft Environmental Impact Statement – Volume I

Summary

Tahoe National Forest

xi

Indicators by 

Resource Measures Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Recreation Non- motorized Opportunities – displacements

Indicator: Access 

to desired nonmotorized 

recreation settings 

and opportunities

Designated area 

(acres) and trails 

(miles) within 5

miles of plowed 

trailheads

89,667 acres /28

miles of designated 

trails within 5 miles 

of trailheads.

20.5 miles of the 

PCT available for 

non-motorized 

recreation within 5 

miles of plowed 

trailheads

62,635 acres /28

miles of designated 

trails within 5 miles 

of trailheads

20.5 miles of the 

PCT available for 

non-motorized 

recreation 

enthusiasts within 5 

miles of plowed 

trailheads

78,258 acres/28

miles of designated 

trails within 5 miles 

of trailheads

20.5 miles of the 

PCT available for 

non-motorized 

recreation 

enthusiasts within 5 

miles of plowed 

trailheads

22,310 acres/28

miles of designated 

trails within 5 miles 

of trailheads

20.5 miles of the 

PCT available for 

non-motorized 

recreation 

enthusiasts within 5 

miles of plowed 

trailheads

89,667 acres/28

miles of designated 

trails within 5 miles 

of trailheads

Indicator: Quality of 

non-motorized 

opportunities

Percent of acres 

available for quiet, 

non-motorized use 

that are within within 

5 miles of plowed 

trailheads

45 percent of the 

acres available for 

quiet, non-motorized 

use provide high 

quality nonmotorized 

opportunities

14.6 percent of the 

acres available for 

quiet, nonmotorized use 

provide high quality 

non-motorized 

opportunities

13.9 percent of the 

acres available for 

quiet, nonmotorized use 

provide high quality 

non-motorized 

opportunities

11.4 percent of the 

acres available for 

quiet, nonmotorized use 

provide high quality 

non-motorized 

opportunities

16.7 percent of the 

acres available for 

quiet, nonmotorized use 

provide high quality 

non-motorized 

opportunities

Recreation Non- motorized conflicts

Public Safety 

Indicator: Areas 

available to nonmotorized 

recreation 

enthusiasts for 

quality nonmotorized 

recreation 

experiences

Size of areas 

(acres) not 

designated for OSV 

use/percent change 

from current 

management

198,271 acres not 

designated for OSV 

use

429,378 acres not 

designated for OSV 

use/116 percent 

increase from 

current 

management

560,301 acres not 

designated for OSV 

use/182 percent 

increase from 

current 

management. 

195,168 acres not 

designated for OSV 

use/a slight 

decrease from 

current 

management.

536,127 acres not 

designated for OSV 

use/53 percent 

decrease from 

current 

management.
Over-snow Vehicle Use Designation 

Tahoe National Forest

xii

Indicators by 

Resource Measures Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Solitude, Air 

quality, Scenery

Indicator: Proximity 

and frequency of 

OSV designations in 

relation to 

designated nonmotorized areas

Solitude: Distance 

of groomed public 

OSV snow trails 

from designated 

areas. Number of 

crossings of linear 

designated areas

The closest OSV 

trail to the Granite 

Chief Wilderness 

boundary is the 

Mosquito Ridge 

marked, not 

groomed OSV trail, 

more than two miles 

to the west.

PCT crossings not 

designated. High 

potential for 

motorized OSVs to 

impact nonmotorized PCT 

experience

Same as 

alternative 1. 

22 designated OSV 

crossings of the 

PCT. High potential 

for motorized OSVs 

to impact nonmotorized PCT 

experience

Same as alternative 

1. 

3 designated OSV 

crossings of the 

PCT. Low potential 

for motorized OSVs 

to impact nonmotorized PCT 

experience

Same as alternative 

1. 

21 designated OSV 

crossings of the 

PCT. High potential 

for motorized OSVs 

to impact nonmotorized PCT 

experience

Same as alternative 

1. 10 designated 

OSV crossings of 

the PCT. OSV use 

would not be 

designated within 

the Foreground of 

the PCT. Very Low 

potential for 

motorized OSVs to 

impact nonmotorized PCT 

experience

Air Quality: 

Qualitative/narrative 

description of 

potential impacts

Potential short-term 

impacts to the 

experience of 

recreational visitors 

in the vicinity of 

OSVs and grooming 

equipment due to 

the smell of exhaust 

emissions 

Potential short-term 

impacts to the 

experience of 

recreational visitors 

in the vicinity of 

OSVs and 

grooming 

equipment due to 

the smell of 

exhaust emissions. 

Fewer acres 

designated for OSV 

use than in existing 

conditions.

Possible short-term 

impacts to the 

experience of 

recreational visitors 

in the vicinity of 

OSV and grooming 

equipment due to 

the smell of exhaust 

emissions. Fewer 

acres designated for 

OSV use than in all 

other alternatives.

Possible short-term 

impacts to the 

experience of 

recreational visitors 

in the vicinity of 

OSV and grooming 

equipment due to 

the smell of exhaust 

emissions. Slightly 

more acres 

designated for OSV 

use than in existing 

conditions.

Possible short-term 

impacts to the 

experience of 

recreational visitors 

in the vicinity of 

OSV and grooming 

equipment due to 

the smell of exhaust 

emissions. Fewer 

acres designated for 

OSV use than in 

alternatives 1, 2 and 

4.

Scenery: 

Qualitative/narrative 

description of 

potential visual 

impacts

Cross-country OSV 

use creates 

temporary tracks 

that crisscross the 

landscape. The 

visual evidence of 

snowmobile use 

decreases as fresh 

snow covers tracks 

or when the snow 

melts.

Description same 

as alternative 1.

Fewer acres 

designated for 

cross-country OSV 

use compared to 

alternative 1, and 

associated visual 

impacts than in 

existing conditions.

Description same as 

alternative 1.

Fewer acres 

designated for 

cross-country OSV 

use compared to 

alternative 1, and 

less associated 

visual impacts than 

in all other 

alternatives.

Description same as 

alternative 1.

Slightly more acres 

designated for 

cross-country OSV 

use compared to 

alternative 1, and 

slightly greater 

associated visual 

impacts than in 

existing conditions.

Description same as 

alternative 1.

Fewer acres 

designated for 

cross-country OSV 

use compared to 

alternative 1, and 

less associated 

visual impacts than 

in alternatives 1, 2 

and 4.
Draft Environmental Impact Statement – Volume I

Summary

Tahoe National Forest

xiii

Indicators by 

Resource Measures Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Potential conflict 

with other 

resource values: 

Proximity of OSV 

use related to other 

resource values

No closure to historic 

structures at 

Robinson Flat.

One acre is 

designated for OSV 

use to protect 

historic buildings

Same as alternative 

2

Same as alternative 

2

Same as alternative 

2
Over-snow Vehicle Use Designation 

Tahoe National Forest

xiv

Indicators by 

Resource Measures Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Recreation Designated Areas

Indicator: 

Wilderness 

Attributes

Size of areas 

(acres) affected and 

duration of impact. 

Qualitative 

description for 

wilderness 

attributes.

4,404 acres 

designated for OSV 

use within 1/2 mile of 

wilderness 

boundaries. 

Potential impacts 

would be short-term 

when snow depth is 

adequate for OSVs 

to access the area.

2,305 acres 

designated for OSV 

use within 1/2 mile 

of designated 

wilderness 

boundaries. 

Potential impacts 

would be shortterm, when snow 

depth is adequate 

for OSVs to access 

the area.

No areas are 

designated for OSV 

use within 1/2 mile 

of designated 

wilderness 

boundaries. 

Potential impacts 

would be very 

unlikely.

5,235 acres 

designated for OSV 

use within 1/2 mile 

of designated 

wilderness 

boundaries. 

Potential impacts 

would be shortterm, during the 

winter while snow 

depth is adequate 

for OSVs to access 

the area.

2,125 acres 

designated for OSV 

use within 1/2 mile 

of designated 

wilderness 

boundaries. 

Potential impacts 

would be shortterm, during the 

winter while snow 

depth is adequate 

for OSVs to access 

the area. Potential 

impacts are less 

than in alternatives 

1, and 4 and slightly 

less than Alternative 

2.

Indicator: Roadless 

Characteristics: 1) 

undisturbed soil, 

water, and air 

(short-term impacts 

to air quality due to 

the presence of 

OSV exhaust), and 

(2) solitude (due to 

the sights and 

sounds of OSVs)

Size of area (acres) 

affected and 

duration of impact. 

Qualitative 

description for 

roadless 

characteristics

Approximately 

109,234 inventoried 

roadless area (IRA) 

acres are designated 

for OSV use.

Short term impacts 

to the roadless 

characteristics 

during the winter 

while snow depth is 

adequate for OSVs 

to access the area.

Approximately 

74,875 IRA acres 

are designated for

OSV use.

Not designating 

OSV use in the 

High Loch Leven 

vicinity within the 

North Fork 

American River IRA 

reduces potential 

impacts on 

roadless 

characteristics.

Approximately 

45,272 IRA acres 

are designated for

OSV use. 

Not designating 

OSV use in same 

areas as alternative 

2, plus PCT/Grubb, 

Devil’s Canyon, 

Coon Canyon, and 

Summit Lake areas 

within the Castle 

Peak IRA reduces

potential impacts on 

roadless 

characteristics more 

than alternatives 1, 

2 and 3.

Approximately 

112,388 IRA acres 

are designated for

OSV use, slightly 

more than in 

alternative 1. 

Potential impacts 

are the same as 

alternative 1.

Approximately 

5,161 IRA acres are 

designated for OSV 

use.

Alternative 5 

provides the most 

protection for 

roadless area 

characteristics when 

compared to all 

other alternatives.
Draft Environmental Impact Statement – Volume I

Summary

Tahoe National Forest

xv

Indicators by 

Resource Measures Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Noise

Indicator:

Opportunities for 

motorized winter 

uses

Size of areas 

(acres) open to 

public, crosscountry OSV use

636,002 acres 

designated for OSV 

use

406,895 acres 

designated for OSV 

use, a 36 percent 

decrease from 

existing conditions. 

275,972 acres 

designated for OSV 

use, a 57 percent 

decrease from 

existing conditions.

641,105 acres 

designated for OSV 

use, a.5 percent 

increase from 

existing conditions.

300,146 acres 

designated for OSV 

use; a 53 percent 

decrease from 

existing conditions. 

Acres and percent 

of designated acres 

that are anticipated 

to have high to 

moderate OSV use 

levels and the 

associated potential 

for noise impacts.

212,857 acres, 33 

percent of acres 

designated for use

are anticipated to 

have high to 

moderate OSV use

191,311 acres, 47 

percent of acres 

designated for use

are anticipated to 

have high to 

moderate OSV use.

161,919 acres, 

58 percent of acres 

designated for use

are anticipated to 

have high to 

moderate OSV use. 

212,873 acres, 

33 percent of acres 

designated for use

are anticipated to 

have high to 

moderate OSV use.

145,420 acres, 

48 percent of acres 

designated for use

are anticipated to 

have high to 

moderate OSV use

Air Quality

Indicator: Estimate 

of change 

(increase/decrease) 

in emissions and 

the potential to 

create adverse 

impacts to air 

quality

Miles of trail open to 

OSV visitor use

265 miles currently 

available for OSV 

use. No known 

violations of the 

Clean Air Act (CAA) 

as a result of OSV 

use 

Approximately 

321 miles would be 

available for OSV 

use. A 21 percent 

increase in miles. 

No violations of the 

CAA are 

anticipated.

Approximately 

280 miles would be 

available for OSV 

use. A 6 percent 

increase. No 

violations of the 

CAA are 

anticipated.

Approximately 

287 miles would be 

available for OSV 

use. An 8 percent 

increase.No 

violations of the 

CAA are 

anticipated.

Approximately 

257 miles would be 

available for OSV 

use. A 3 percent 

reduction. No 

violations of the 

CAA are anticipated

Acres designated 

for public crosscountry OSV use

636,002 acres 

designated for crosscountry OSV use. 

There are no known 

violations of the CAA 

as a result of OSV

use under the 

existing condition

406,895 acres 

designated for 

cross-country OSV 

use. A 36 percent 

reduction from 

existing conditions. 

No violations of the 

CAA are 

anticipated.

275,972 acres 

designated for OSV 

use. A 57 percent 

reduction from 

existing conditions. 

No violations of the 

CAA are 

anticipated.

641,105 acres 

designated for V 

use. Less than 1 

percent increase 

from existing 

condition. 

No violations of the 

CAA are 

anticipated.

300,146 acres 

designated for OSV 

use, a 53 percent 

reduction from 

existing conditions. 

No violations of the 

CAA are 

anticipated.
Over-snow Vehicle Use Designation 

Tahoe National Forest

xvi

Indicators by 

Resource Measures Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Indicator: Potential 

effects of OSV 

emissions to create 

adverse impacts to 

air quality

Shifts in OSV use in 

relation to Class I 

and Class II areas 

(Desolation and 

Granite Chief 

Wildernesses).

OSV areas 

designated for OSV 

use are within 1 mile 

of a Class I area. 

There are no known 

violations of the CAA 

or impacts to the 

Class I or II area as 

a result of OSV use 

under the existing 

condition.

OSV areas 

designated for OSV 

use are within 1 

mile of a Class I 

area and 2 miles to 

a Class II area. 

OSV designated 

crossings on the 

PCT would occur 

within 2 miles of 

Class I area. No 

known violations of 

the CAA under this 

alternative 

OSV areas 

designated for use 

are within 1 mile of 

a Class I area and 2 

miles to a Class II 

area. OSV 

designated 

crossings on the 

PCT would occur 

within 2 miles of 

Class I area. No 

known violations of 

the CAA under this 

alternative

OSV areas 

designated for use 

are within 1 mile of 

a Class I area and 

2 miles to a Class II 

area. OSV 

designated 

crossings 

established on the 

PCT would occur 

within 2 miles of 

Class I area. N o 

known violations of 

the CAA under this 

alternative

OSV areas 

designated for OSV 

use are within 1 

mile of a Class I 

area and 2 miles to 

a Class II area. 

OSV designated 

crossings 

established on the 

PCT would occur 

within 2 miles of 

Class I area. No 

known violations of 

the CAA under this 

alternative

Hydrology – Water Quality

Indicator: Number 

of snowmobiles per 

year using trails 

across the Forest

Total amount of use 

can be compared to 

use amounts in 

Yellowstone and 

other studies to 

gauge potential 

water quality effects

Higher Yellowstone 

OSV use levels than 

use levels on the 

TNF resulted in no 

impaired water 

quality Not likely to 

adversely affect 

water quality of 

snowmelt from OSV 

exhaust emissions. 

Provides the lowest 

level of protection.

Description same 

as alternative 1. 

Less acres 

designated for OSV 

use than alternative 

1 and established 

snow depths 

results in OSV 

exhaust emissions

negligible and not 

be expected to 

exceed water 

quality standards. 

Description same as 

alternative 1.

Approximately 

131,000 less acres 

designated for OSV 

use than alternative 

2 and higher 

minimum snow 

depths results in 

OSV exhaust 

emissions negligible 

and not be expected 

to exceed water 

quality standards. 

Provides more 

protection than 

alternatives 1, 2, 

and 4.

Description same as 

alternative 1.

Slightly higher 

number of acres 

designated for OSV 

use than alternative 

1, snow depths and 

effects same as 

alternative 2. 

Provides more 

protection than 

alternative 1, less 

than alternative 3.

Description same as 

alternative 1.

Provides the most 

protection of all 

alternatives due 

highest snow 

depths.
Draft Environmental Impact Statement – Volume I

Summary

Tahoe National Forest

xvii

Indicators by 

Resource Measures Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Soil Productivity and Stability

Indicator: 

Designated OSV 

use on sensitive 

soils

Size of areas 

(acres) designated 

for OSV use on 

sensitive soils

190,169 acres on

sensitive soil types 

141,205 acres 

acres on sensitive 

soil types.

This has less 

sensitive soils than 

alternatives 1 and 

4, but greater than 

alternative 3 and 5. 

89,037 acres acres 

on sensitive soil 

types.

This has the least 

amount of sensitive 

soils designated for

OSV use. 

193,213 acres acres 

on sensitive soil 

types.

This has the most 

acreage of sensitive 

soils designated for

OSV use.

92,429 acres acres 

acres on sensitive 

soil types.

This is less than 

alternatives 1, 2, 

and 4.

Indicator: Minimum 

snow depths on 

trails designated for 

OSV use

Depth of snow 

(inches)

No minimum snow 

depth. Soil resource 

damage could occur 

where snow levels 

are not sufficient to 

prevent contact 

directly with trail.

May lead to 

increases in erosion 

where bare soil is 

exposed.

6-inch minimum 

snow depth. May 

potentially create 

conditions in which 

the road surface is 

exposed to OSVs.

May lead to some 

soil erosion or 

rutting of the trail

surface. 

18-inch minimum 

snow depth. May be

sufficient to prevent 

contact of OSVs 

with bare soil.

6-inch minimum 

snow depth. May 

potentially create 

conditions in which 

the trail surface is 

exposed to OSVs. 

Potential for some 

soil erosion or 

rutting of trail

surface. 

24-inch minimum 

snow depth. 

Sufficient to prevent 

contact of OSVs 

with bare soil.

Indicator: Minimum 

snow depths in 

areas designated 

for OSV use

Depth of snow 

(inches)

No minimum snow 

depth. Soil resource 

damage could occur 

where snow levels 

are not sufficient to 

prevent contact with 

the trail. This could 

lead to long term 

decreases in soil 

productivity 

Potential effects to 

the soil is unlikely 

to be affected with 

at least 12 inches 

of snow covering 

the soil surface.

Potential effects to 

the soil is unlikely to 

be affected with at 

least 18 inches of 

snow covering the 

soil surface.

Potential effects to 

the soil is unlikely to 

be affected with at 

least 12 inches of 

snow covering the 

soil surface.

Potential effects to 

the soil is unlikely to 

to be affected with 

at least 24 inches of 

snow covering the 

soil surface.
Over-snow Vehicle Use Designation 

Tahoe National Forest

xviii

Indicators by 

Resource Measures Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Terrestrial Wildlife - Federally Listed, Proposed Species – North American wolverine

Indicator: Potential 

for disturbance to 

individuals from 

OSV use and 

increased human 

presence, or injury 

or mortality of 

individuals

Acres designated 

for OSV use and 

conducive to OSV 

use with potential to 

affect habitat 

142,139 142,139 145,484 155,302 132,499

Terrestrial Wildlife R5 Sensitive species – Pacific Marten

Indicator: Potential 

for injury or mortality 

of individuals from 

OSV use or related 

activities

Acres designated 

for OSV use and 

conducive to OSV 

use in winter habitat

19,612 19,612 19,588 25,607 17,846

Indicator: Potential 

for loss of habitat 

connectivity

Acres designated 

for OSV use and 

conducive to OSV 

within habitat 

connectivity 

corridors 

18,297 18,297 18,107 18,411 17,511

Terrestrial Wildlife R5 Sensitive species – California spotted owl

Indicator: Potential 

for disturbance to or 

displacement of 

individuals from 

noise and increased 

human presence, 

injury or mortality of 

individuals

Acres designated 

for OSV use and 

conducive to OSV 

use of important 

habitat with 

potential to be 

impacted by OSV 

use

6,262 2,388 6,262 8,453 5,411

Acres designated 

for OSV use and 

conducive to OSV 

use of buffered 

CSO activity centers 

with potential to be 

impacted by OSV 

use

1,605 2,388 1,605 2,093 1,344
Draft Environmental Impact Statement – Volume I

Summary

Tahoe National Forest

xix

Indicators by 

Resource Measures Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Terrestrial Wildlife R5 Sensitive species – Northern Goshawk

Indicator: Potential 

for disturbance to 

individuals from 

noise and increased 

human presence, or

injury or mortality of 

individuals

Acres designated 

for OSV use and 

conducive to OSV 

use of important 

habitat with 

potential to be 

impacted by OSV 

use

31,160 18,540 29,898 31,160 25,543

Acres of buffered 

NGO PACs with 

potential to be 

impacted by OSV 

use

700 420 700 778 632

Terrestrial Wildlife R5 Sensitive species – Bald Eagle

Indicator: Potential 

for disturbance to 

individuals from 

noise and increased 

human presence, 

injury or mortality of 

individuals

Acres designated 

for OSV use and 

conducive to OSV 

use of high value 

reproductive habitat 

potentially impacted 

by OSV use

4,124 1,375 4,748 4,259 4,124

Acres designated 

for OSV use and 

conducive to OSV 

use of buffered bald 

eagle nests 

potentially impacted 

by OSV use

18 18 18 18 18 

Terrestrial Wildlife R5 Sensitive species – Great Gray Owl

Indicator: Potential 

for disturbance to 

individuals from 

noise and increased 

human presence, 

injury or mortality of 

individuals, or 

habitat modification

Acres designated 

for OSV use and 

conducive to OSV 

use of highreproductive habitat 

potentially impacted 

by OSV use 

914 914 640 924 841
Over-snow Vehicle Use Designation 

Tahoe National Forest

xx

Indicators by 

Resource Measures Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Aquatic Resources Threatened and Endangered Species: California red-legged frog

Indicator: Aquatic 

habitat

Acres designated 

for cross-country 

OSV in critical and 

suitable habitat

Critical habitat: 930

Suitable habitat: 

48,212

Critical habitat: 0

Suitable habitat: 

2,065

Critical habitat: 0

Suitable habitat: 

4,908

Critical habitat: 930

Suitable habitat: 

48,212

Critical habitat: 0

Suitable habitat: 

2,082

Critical and suitable 

habitat (acres) 

within 100 feet of 

OSV trails

Critical habitat: 0

Suitable habitat: 40

Critical habitat: 0

Suitable habitat: 

330

Critical habitat: 0

Suitable habitat: 40

Critical habitat: 0

Suitable habitat: 91

Critical habitat: 0

Suitable habitat: 40

Aquatic Resources Threatened and Endangered Species: Sierra Nevada yellow-legged frog

Indicator: Aquatic 

habitat

Acres designated 

for cross-country 

OSV in critical and 

suitable habitat

Critical habitat: 

84,795

Suitable habitat: 

30,750

Critical habitat: 

76,241

Suitable habitat: 

23,212

Critical habitat: 

47,520

Suitable habitat: 

17,320

Critical habitat: 

84,846

Suitable habitat: 

30,949

Critical habitat: 

33,125

Suitable habitat: 

15,600

Critical and suitable 

habitat (acres) 

within 100 feet of 

OSV trails

Critical habitat: 657

Suitable habitat: 301

Critical habitat: 665

Suitable habitat: 

342

Critical habitat: 573

Suitable habitat: 

299

Critical habitat: 707

Suitable habitat: 

327

Critical habitat: 626

Suitable habitat: 

292

Botany Resources Threatened and Endangered Species

Indicator: Species

presence

Acres in designated 

high OSV use areas

0 0 0 0 0

Acres in areas

designated for OSV 

use

57 0 0 57 0

Botany Resources Sensitive Species

Indicator: Species

presence

Acres in designated 

high OSV use areas

308 253 102 354 237

Acres in areas 

designated for OSV 

use

2,051 1,294 902 2,062 986
Draft Environmental Impact Statement – Volume I

Summary

Tahoe National Forest

xxi

Indicators by 

Resource Measures Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Socioeconomics

Indicator:

Employment 

Number of jobs and 

amount of labor 

income

No change due to 

management; 

increased visitor use 

over time would 

increase number of 

jobs, labor income, 

and tax revenue

Increased OSV 

visitation would 

support additional 

employment, labor 

income, and tax 

revenue in the local 

area; potential for 

reduction in nonmotorized winter 

recreation visitation 

could offset 

increased 

economic activity

Potential for minor 

changes in 

motorized and nonmotorized winter 

recreation use are 

not expected to 

meaningfully affect 

recreation-related 

employment, labor 

income, or tax 

revenue in local 

area

Increased OSV 

visitation would 

support additional 

employment, labor 

income, and tax 

revenue in the local 

area; potential for 

reduction in nonmotorized winter 

recreation visitation 

could offset 

increased economic 

activity

OSV visitation 

would not 

measurably change 

relative to current 

conditions, 

therefore, 

recreation-related 

employment, labor 

income, and tax 

revenue in the local 

area would not 

change

Indicator: 

Recreation visitation

Number of 

recreation visits

No change; visitor 

use expected to 

increase over time

OSV visitation 

expected to 

increase due to 

more miles of trail 

available for 

grooming; 

increased OSV 

visitation may 

crowd out some 

non-motorized 

winter recreation 

users

No change. Visitor 

use expected to 

increase over time

OSV visitation 

expected to 

increase due to 

more miles of trail 

available for 

grooming; increased 

OSV visitation may 

crowd out some 

non-motorized 

winter recreation 

users

OSV visitation is not 

expected to change 

due to small change 

in miles of OSV 

trails available for 

grooming; nonmotorized winter 

recreation may 

increase due to 

fewer acres 

designated for 

cross-country OSV 

use

Indicator: Values, 

beliefs, and 

attitudes

Qualitative 

evaluation of public 

values, beliefs, and 

attitudes

User conflict may 

increase due to 

population growth 

and increased visitor 

use

Increased OSV 

visitation may affect 

non-motorized 

winter recreation 

users’ quality of life

No expected effects 

to motorized or nonmotorized winter 

recreation users’ 

quality of life

Increased OSV 

visitation may affect 

non-motorized 

winter recreation 

users’ quality of life

OSV users’ quality 

of life may decline if 

they travel farther or 

face site 

competition; nonmotorized 

recreation users 

would benefit from 

decreased 

likelihood of user 

conflict
Over-snow Vehicle Use Designation 

Tahoe National Forest

xxii

Indicators by 

Resource Measures Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Indicator: Lowincome and minority 

populations

Qualitative 

evaluation of 

disproportionate 

effects to lowincome and minority 

populations

No change; climate 

change may 

increase distances 

winter recreation 

users must travel for 

adequate snow 

depth

No change in cost; 

climate change 

may increase 

distances winter 

recreation users 

must travel for 

adequate snow 

depth

No change in cost 

due; climate change 

may increase 

distances winter 

recreation users 

must travel for 

adequate snow 

depth

No change in cost; 

climate change may 

increase distances 

winter recreation 

users must travel for 

adequate snow 

depth

OSV users would 

have to travel 

farther to access 

open areas or 

groomed trails; 

increased travel 

costs would 

disproportionately 

affect lower income 

individuals and 

families
Draft Environmental Impact Statement – Volume I

Contents

Tahoe National Forest

xxiii

Contents

Summary of the Draft Environmental Impact Statement .......................................................................v

Purpose and Need...............................................................................................................................v

Modified Proposed Action.................................................................................................................v

Significant Issues .............................................................................................................................vii

Alternatives Considered in Detail....................................................................................................vii

Summary of Environmental Impacts......................................................................................................x

Acronyms ..........................................................................................................................................xxix

Chapter 1. Purpose and Need for Action................................................................................................1

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

Definitions..........................................................................................................................................1

Background ........................................................................................................................................2

Purpose and Need.............................................................................................................................12

Modified Proposed Action...............................................................................................................12

Decision Framework........................................................................................................................12

Public Involvement ..........................................................................................................................13

Issues................................................................................................................................................14

Chapter 2. Alternatives.........................................................................................................................19

Introduction......................................................................................................................................19

How Alternatives were Developed ..................................................................................................21

Alternatives Considered in Detail....................................................................................................22

Comparison of Alternatives.............................................................................................................42

Suggested Alternatives or Alternative Components Considered .....................................................47

Chapter 3. Affected Environment and Environmental Consequences .................................................51

Introduction......................................................................................................................................51

Recreation Resources.......................................................................................................................52

Noise ..............................................................................................................................................107

Air Quality .....................................................................................................................................125

Hydrology ......................................................................................................................................145

Soils................................................................................................................................................179

Terrestrial Wildlife.........................................................................................................................189

Terrestrial Wildlife Species of Public Interest...............................................................................246

Management Indicator Wildlife Species........................................................................................249

Migratory Landbirds......................................................................................................................252

Aquatics .........................................................................................................................................253

Botany – Listed and Sensitive Species...........................................................................................277

Other Botanical Species.................................................................................................................306

Socioeconomic Conditions ............................................................................................................338

Cultural Resources.........................................................................................................................359

Engineering and Roads ..................................................................................................................363

Chapter 4. List of Preparers and Contributors....................................................................................377

List of Preparers.............................................................................................................................377

Interdisciplinary Team Consultants ...............................................................................................378

References..........................................................................................................................................385

Air Quality .....................................................................................................................................385

Botany............................................................................................................................................386

Other Botanical Species.................................................................................................................388

Aquatic Resources..........................................................................................................................390

Hydrology ......................................................................................................................................400
Over-Snow Vehicle Use Designation

Tahoe National Forest

xxiv

Noise ..............................................................................................................................................401

Recreation ......................................................................................................................................402

Socioeconomic...............................................................................................................................403

Soils................................................................................................................................................403

Transportation/Engineering............................................................................................................404

Terrestrial Wildlife.........................................................................................................................405

Management Indicator Species......................................................................................................414

Glossary..............................................................................................................................................415

List of Tables

Table S-1. Significant issues ................................................................................................................vii

Table S-2. Summary of alternatives considered in detail....................................................................viii

Table S-3 Summary of environmental effects........................................................................................x

Table 1. Road and trail terminology - definitions ..................................................................................2

Table 2. Specific (and minimization) criteria (areas and trails proposed for designation for OSV use) 7

Table 3. OSV use designations - alternative 1......................................................................................23

Table 4. OSV Trails – alternative 1......................................................................................................24

Table 5. OSV use designations under alternative 2..............................................................................27

Table 6. OSV Trails– alternative 2.......................................................................................................27

Table 7. Designated Pacific Crest Trail OSV crossings (displayed from south to north) – alternative 2

......................................................................................................................................................29

Table 8. OSV use designations - alternative 3......................................................................................31

Table 9. OSV Trails – alternative 3......................................................................................................32

Table 10. Designated Pacific Crest Trail OSV crossings (displayed from south to north) – alternative 

3....................................................................................................................................................33

Table 11. OSV use designations under alternative 4............................................................................34

Table 12. OSV Trails – alternative 4....................................................................................................35

Table 13. Designated Pacific Crest Trail OSV crossings (displayed from south to north) – alternative 

4....................................................................................................................................................37

Table 14. OSV use designations for alternative 5 ................................................................................39

Table 15. OSV Trails – alternative 5....................................................................................................40

Table 16. Designated Pacific Crest Trail OSV crossings (displayed from south to north) – alternative 

5....................................................................................................................................................41

Table 17. Comparison of areas to be designated for OSV use, by alternative (acres) .........................42

Table 18. Comparison of trails for OSV use, by alternative (miles)....................................................43

Table 19. Resource indicators and measures for assessing effects to recreation resources..................59

Table 20. Tahoe National Forest recreation opportunity spectrum classes..........................................65

Table 21. Overview of State of California OSV Grooming Program Activity on the Tahoe National 

Forest............................................................................................................................................67

Table 23. Tahoe National Forest inventoried roadless areas................................................................69

Table 24. National Visitor Use Management winter activities.............................................................72

Table 25. California OSV registration for counties in Tahoe National Forest, 2009 through 2014.....72

Table 26. California statewide OSV registration, 2009 through 2014 .................................................72

Table 27. Tahoe National Forest OSV visitor use................................................................................73

Table 28. Recreation resource indicators and measures for the existing condition, alternative 1........77

Table 29. Recreation resource indicators and measures for alternative 2 direct and indirect effects...84

Table 30. Recreation resource indicators and measures for alternative 3 direct and indirect effects...90

Table 31. Recreation resource indicators and measures for alternative 4 direct and indirect effects...95

Table 32. Recreation resource indicators and measures for alternative 5 direct and indirect effects.101

Table 33. Resource indicators and measures for alternative 2 direct and indirect effects..................110
Draft Environmental Impact Statement – Volume I

Contents

Tahoe National Forest

xxv

Table 34. Noise resource indicators and measures for alternative 1 ..................................................112

Table 35. Examples of Comparative Sound Levels* .........................................................................114

Table 36. Resource indicators and measures for alternative 2 direct and indirect effects..................115

Table 37. Resource indicators and measures for alternative 3 direct and indirect effects..................120

Table 38. Resource indicators and measures for alternative 4 direct and indirect effects..................121

Table 39. Resource indicators and measures for alternative 5 direct and indirect effects..................122

Table 40. Summary comparison of how the alternatives address the key issues for noise ................124

Table 41. State and National Ambient Air Quality Standards ...........................................................127

Table 42. Federal non-attainment areas for criteria pollutants...........................................................135

Table 43. State designated non-attainment areas for criteria pollutants.............................................136

Table 44. Number of required and existing sites by CBSA ...............................................................137

Table 45. Estimated annual average emissions (tons/year) by air district for area-wide, stationary and 

mobile sources............................................................................................................................138

Table 46. Exhaust emission standards for snowmobiles....................................................................139

Table 47. Tahoe National Forest OSV visitor use..............................................................................140

Table 48. Resource indicators and measures for air quality, existing condition ................................140

Table 49. Emission estimate (tons per year) for OSV use on the Tahoe National Forest ..................141

Table 50. Tahoe National Forest LRMP guidelines relevant to watershed resources........................145

Table 49. Resource indicators and measures used to determine impacts on soil and water resources

....................................................................................................................................................152

Table 50. Hydrologic characteristics of the OSV analysis area within Tahoe National Forest..........157

Table 51. Sediment yields from reservoir surveys, suspended sediment records, and other estimates 

(Kattelmann 1996)......................................................................................................................158

Table 52. Tahoe National Forest 2011 OHV/OSV Monitoring and Management Program: 2011 

Monitoring Results.....................................................................................................................159

Table 53. Modelled erosion risk rating by major river basin (USDA Forest Service 2012)..............161

Table 54. Impaired waterbodies on the Tahoe National Forest listed on the EPA 303(d) List..........162

Table 55. Riparian conservation areas (RCAs) adjacent to aquatic features as designated by the Sierra

Nevada Forest Plan Amendment Record of Decision (SNFP ROD 2004)..................................175

Table 56. Compliance with beneficial uses of water on the Tahoe National Forest ..........................177

Table 57. Water quality standards of concern for OSVs.....................................................................178

Table 58. Resource indicators and measures used to determine impacts on soil resources...............182

Table 59. Resource indicators and measures for alternative 1 ...........................................................185

Table 60. Resource indicators and measures for soil resources direct and indirect effects, alternatives 

2, 3, 4 and 5 ................................................................................................................................187

Table 61. Resource indicators and measures for assessing effects to terrestrial wildlife...................194

Table 62. Terrestrial threatened, endangered, proposed, and candidate (TEPC) species and designated 

or proposed critical habitat considered within this analysis.......................................................198

Table 63. Resource indicators and measures for assessing effects to wolverine................................202

Table 64. Acres of wolverine habitat with potential to be impacted by OSV use and related activities, 

by alternative ..............................................................................................................................203

Table 65. Terrestrial Forest Service Sensitive Species considered in this analysis............................204

Table 66. Resource indicators and measures for assessing effects to marten ....................................207

Table 67. Acres of marten winter habitat by alternative ....................................................................210

Table 68. Acres of marten habitat connectivity corridors, by alternative ..........................................211

Table 69. Resource indicators and measures for assessing effects to California spotted owl............214

Table 70. Acres of known California spotted owl activity centers, buffered by 0.70 mile, with 

potential to be impacted by OSV use and related activities, by alternative................................217

Table 71. Acres of important California spotted owl habitat with potential to be impacted by OSV use 

and related activities, by alternative ...........................................................................................217

Table 72. Resource indicators and measures for assessing effects to northern goshawk...................221
Over-Snow Vehicle Use Designation

Tahoe National Forest

xxvi

Table 73. Acres of goshawk activity centers, buffered by 0.25 mile, by alternative..........................223

Table 74. Acres of important goshawk habitat by alternative............................................................224

Table 75. Resource indicators and measures for assessing effects to bald eagles..............................236

Table 76. Acres of bald eagle nest sites, buffered by 660 feet by alternative ....................................237

Table 77. Acres of high-value bald eagle reproductive habitat, by alternative ..................................237

Table 78. Resource indicators and measures for assessing effects to great gray owl.........................239

Table 79. Acres of high-value great gray owl reproductive habitat with highest potential to be 

impacted by OSV use and related activities, by alternative .......................................................241

Table 80. Additional terrestrial species of interest identified during public scoping.........................246

Table 81. Resource indicators and measures for assessing effects to mule deer on winter range......246

Table 82. Acres of mule deer winter range with potential to be impacted by OSV use and related 

activities......................................................................................................................................247

Table 83. Resource indicators and measures for assessing effects to subnivean species...................248

Table 84. Selection of MIS for Project-Level Habitat Analysis for the Tahoe OSV Use Designation

....................................................................................................................................................251

Table 85. Aquatic indicators and measures for assessing effects.......................................................255

Table 86. Threatened, endangered, proposed, and sensitive (TEPS) aquatic species considered and 

designated or proposed critical habitat considered in this analysis............................................257

Table 87. Tahoe National Forest 2011 OHV/OSV Monitoring and Management Program: 2011 

Monitoring Results.....................................................................................................................266

Table 88. Alternatives comparison of possible effects to California red-legged frog critical habitat on 

the Tahoe National Forest ..........................................................................................................267

Table 89. Alternatives comparison of possible effects to California red-legged frog suitable habitat on 

the Tahoe National Forest ..........................................................................................................267

Table 90. Alternatives comparison of potential effects to Sierra Nevada Yellow-legged frog critical 

habitat on the Tahoe National Forest..........................................................................................270

Table 91. Alternatives comparison of possible effects to Sierra Nevada yellow-legged frog suitable 

habitat on the Tahoe National Forest..........................................................................................270

Table 92. Botanical resources indicators and measures for assessing effects....................................280

Table 93. Threatened, endangered or proposed plant species considered..........................................281

Table 94. TEPS plant indicators and measures for alternative 1........................................................296

Table 95. TEPS plant indicators and measures for alternative 2........................................................297

Table 96. TEPS plant indicators and measures for alternative 3........................................................299

Table 97. TEPS plant indicators and measures for alternative 4........................................................301

Table 98. TEPS plant indicators and measures for alternative 5........................................................302

Table 99. TEPS plant summary of measures for all alternatives........................................................304

Table 100. Botanical resources indicators and measures for assessing effects..................................310

Table 101. Special Interest plant species and communities considered .............................................312

Table 102. Botanical resources indicators and measures for alternative 1.........................................328

Table 103. Botanical resources indicators and measures for alternative 2.........................................329

Table 104. Botanical resources indicators and measures for alternative 3.........................................331

Table 105. Botanical resources indicators and measures for alternative 4.........................................332

Table 106. Botanical resources indicators and measures for alternative 5.........................................334

Table 107. Botanical resources summary of measures for all alternatives.........................................336

Table 108. Socioeconomic resource indicators and measures for assessing effects ..........................339

Table 109. Resource indicators and measures for socioeconomic resources, existing condition ......341

Table 110. Demographic characteristics by county............................................................................341

Table 111. Economic characteristics by county .................................................................................342

Table 112. Environmental justice characteristics by county ..............................................................346

Table 113. Socioeconomic resource indicators and measures for alternative 1 .................................348
Draft Environmental Impact Statement – Volume I

Contents

Tahoe National Forest

xxvii

Table 114. Socioeconomic resource indicators and measures for alternative 2 direct and indirect 

effects .........................................................................................................................................349

Table 115. Socioeconomic resource indicators and measures for alternative 2 cumulative effects...350

Economic Activity..............................................................................................................................351

Table 116. Socioeconomic resource indicators and measures for alternative 3 direct and indirect 

effects .........................................................................................................................................352

Table 117. Socioeconomic resource indicators and measures for alternative 4 direct and indirect 

effects .........................................................................................................................................353

Table 118. Socioeconomic resource indicators and measures for alternative 5 direct and indirect 

effects .........................................................................................................................................354

Table 119. Socioeconomic resource indicators and measures for alternative 5 cumulative effects...355

Table 120. Summary comparison of socioeconomic effects..............................................................357

Table 121. Engineering and roads resource indicators and measures for alternative 1......................366

Table 122. Engineering and roads resource indicators and measures for alternative 1......................367

Table 123. Resource indicators and measures for alternative 2 .........................................................368

Table 124. Engineering and roads resource indicators and measures for alternative 2 cumulative 

effects .........................................................................................................................................369

Table 125. Engineering and roads resource indicators and measures for alternative 3......................370

Table 126. Engineering and roads resource indicators and measures for alternative 3 cumulative 

effects .........................................................................................................................................370

Table 127. Engineering and roads resource indicators and measures for alternative 4......................371

Table 128. Engineering and roads resource indicators and measures for alternative 4 cumulative 

effects .........................................................................................................................................372

Table 129. Engineering and roads resource indicators and measures for alternative 5......................373

Table 130. Engineering and roads resource indicators and measures for alternative 5 cumulative 

effects .........................................................................................................................................373

List of Figures

Figure 1. Vicinity map..........................................................................................................................11

Figure 7. Noise analysis on the Andesite Ridge trail .........................................................................116

Figure 8. Noise analysis for the French Meadows Area.....................................................................117

Figure 9. Noise analysis for the Barker Pass Area .............................................................................118

Figure 10. Designated air basins in California ...................................................................................132

Figure 11. Class I areas in California .................................................................................................134

Figure 12. Modelled landscape erosion values by HUC6 watershed (USDA Forest Service 2012)..160

Draft Environmental Impact Statement – Volume I

Acronyms

Tahoe National Forest

xxix

Acronyms

BAT Best available technology

BMP Best management practice

CAA Clean Air Act

CAAQS California Ambient Air Quality Standards 

CARB California Air Resources Board

CVC California Vehicle Code

CWA Clean Water Act 

DEIS Draft Environmental Impact Statement

DEM Digital Elevation Model

GIS Geographic Information System

IRA Inventoried roadless area

LRMP Land and resource management plan (forest plan)

MVUM Motor vehicle use map

NAAQS National Ambient Air Quality Standards 

NEPA National Environmental Policy Act

NFMA National Forest Management Act

NFS National Forest System

NVUM National Visitor Use Monitoring 

OHMVR Off-Highway Motor Vehicle Recreation Division

OHV Off-highway Vehicle

OSV Over-snow Vehicle

PCT Pacific Crest National Scenic Trail

RCA Riparian conservation area

RNA Research natural area

RCO Riparian conservation objectives

RFA Recreation Facility Analysis

ROD Record of Decision

ROS Recreation Opportunity Spectrum

SDWA Safe Drinking Water Act

Revised Draft Environmental Impact Statement – Volume I

Chapter 1. Purpose and Need

Tahoe National Forest

1

Chapter 1. Purpose and Need for Action

Document Structure

The Forest Service has prepared this environmental impact statement (EIS) in compliance with the 

National Environmental Policy Act (NEPA) and other relevant Federal and State laws and regulations. 

This EIS discloses the direct, indirect, and cumulative environmental impacts that would result from 

the proposed action and alternatives. The document is organized into four chapters: 

• Chapter 1. Purpose and Need for Action: This chapter briefly describes the modified 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. 

• Chapter 2. Alternatives, including the Modified Proposed Action: This chapter provides a 

detailed description of the agency’s modified 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 a summary table comparing the Modified Proposed Action and alternatives with 

respect to their environmental impacts. Detailed maps for each alternatives can be found in 

figures 2 through 6 in the map package.

• Chapter 3. Affected Environment and Environmental Consequences: This chapter describes 

the environmental impacts of the modified proposed action and alternatives. 

• Chapter 4. Consultation and Coordination: This chapter provides a list of preparers and 

agencies consulted during the development of the environmental impact statement. 

• 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 Supervisor’s Office in Nevada 

City, California.

This document is tiered to the 1990 Tahoe National Forest Land and Resource Management Plan, as 

amended, 2010 Over Snow Vehicle Program Final Environmental Impact Report, Program Years 

2010 – 2020, by the State of California Department of Parks and Recreation, Off-Highway Motor 

Vehicle Recreation (OHMVR) Division (California Department of Parks and Recreation, Off 

Highway Motor Vehicle Recreation Division 2010).

Definitions

Route categories and travel planning definitions applicable to this project (table 1) are based on the 

definitions in 36 CFR 212 – Travel Management. For a complete list of terms, please refer to the 

glossary found at the end of this document.
Over-Snow Vehicle Use Designation

Tahoe National Forest

2

Table 1. Road and trail terminology - definitions 

Term Definition

Administrative Use Motorized vehicle use associated with management activities or projects 

on National Forest System land administered by the Forest Service or 

under authorization of the Forest Service. Management activities include 

but are not limited to: law enforcement, timber harvest, reforestation, 

cultural treatments, prescribed fire, watershed restoration, wildlife and fish 

habitat improvement, private land access, allotment management 

activities, and mineral exploration and development that occur on National 

Forest System land administered by the Forest Service or under 

authorization of the Forest Service. 

Area A discrete, specifically delineated space that is smaller, and, except for 

over-snow vehicle use, in most cases much smaller, than a Ranger 

District.

Cross-country Over-snow 

Vehicle Use

Public over-snow vehicle use that occurs off of snow trails designated for 

over-snow vehicle use, but within areas designated for public over-snow 

vehicle use. 

Designated Road or Trail or Area A National Forest System road, National Forest System trail, or an area 

on National Forest System lands that is designated for over-snow vehicle 

use pursuant to 36 CFR 212.51 on an over-snow vehicle use map (36 

CFR 212.1).

1

Designation of over-snow vehicle 

use 

Designation of a National Forest System road, a National Forest System 

trail, or an area on National Forest System lands where over-snow vehicle 

use is allowed pursuant to CFR 212.81.

Foreground Seen areas and distance zones are determine the relative sensitivity of 

scenes based on their distance from an observer. These zones are 

identified as Foreground (up to 1/2 mile from the viewer), Middleground 

(up to 4 miles from the foreground), and Background (4 miles from the 

viewer to the horizon). 

Forest road or trail A road or trail wholly or partially within or adjacent to and serving the 

[National Forest System (NFS)] that is determined to be necessary for the 

protection, administration, and utilization of the NFS and the use and 

development of its resources (36 CFR 212.1)

Non-motorized use A term used in this document to refer to travel other than that defined as 

motorized. For example, hiking, riding horses, or mountain biking. 

Over-snow vehicle (OSV) A motor vehicle that is designed for use over snow and that runs on a 

track or tracks and/or a ski or skis, while in use over snow (36 CFR 

212.1). Class 1 OSVs are over-snow vehicles 50 inches or less in width at 

the widest point on the vehicle; Class 2 OSVs are over-snow vehicles 

more than 50 inches in width at the widest point on the vehicle.

Over-snow vehicle use map A map reflecting roads, trails, and areas designated for over-snow vehicle 

use on an administrative unit or a Ranger District of the National Forest 

System.

Trail A route 50 inches wide or less or a route over 50 inches wide that is 

identified and managed as a trail (36 CFR 212.1). 

Background

This analysis responds to requirements in the Federal regulations for the management of OSV use on 

national forests (36 CFR Part 212, Subpart C), as well as a settlement agreement in the case of 

Snowlands Network et al. v. U.S. Forest Service (Case No. 2:11-cv-02921-MCE-DAD, E.D. Cal.) 

 1 The decision resulting from this analysis would not designate National Forest System roads for public OSV use. Public 

OSV trails that would overlay existing National Forest System roads would be designated as National Forest System trails 

where public OSV use is allowed.
Revised Draft Environmental Impact Statement – Volume I

Chapter 1. Purpose and Need

Tahoe National Forest

3

regarding the environmental impacts of the grooming of snow trails for OSV use on five national 

forests, including the Tahoe National Forest. The Forest Service will comply with the terms of the 

settlement agreement for the Tahoe National Forest by completing this analysis. 

Furthermore, additional terms of the Settlement Agreement require the Forest Service to:

• Analyze ancillary activities such as the plowing of related parking lots and trailheads as part of 

the effects analysis;

• Consider a range of alternative actions that would result in varying levels of OSV use; and

• Consider an alternative submitted by Plaintiffs and/or Interveners in the NEPA analysis, so long 

as the alternative meets the purpose and need, and is feasible and within the scope of the NEPA 

analysis, and Plaintiffs and/or Interveners provide the Forest Service with a detailed description 

of that alternative during the scoping period for the NEPA analysis.

Travel Management Regulations – Subpart C: “Use by Over-snow 

Vehicles”

The Forest Service published its final rule for Subpart C of the Forest Service’s Travel Management 

Regulations (36 CFR Part 212) in the Federal Register on January 27, 2015 (80 FR 4500). The rule 

became effective on February 27, 2015 and states, in part: 

“Over-snow vehicle use on National Forest System roads, on National Forest System trails, and 

in areas on National Forest System lands shall be designated by the Responsible Official on 

administrative units or Ranger Districts, or parts of administrative units or Ranger Districts, of 

the National Forest System where snowfall is adequate for that use to occur, and, if appropriate, 

shall be designated by class of vehicle and time of year...” (36 CFR §212.81(a)).

Designations of trails and areas for over-snow vehicle use made as a result of the analysis in this EIS 

would conform to Subpart C of the Travel Management Regulations. 

Consistent with the Travel Management Regulations at 36 CFR Part 212 Subpart C, designated public 

OSV areas and trails would be displayed on a publicly available over-snow vehicle use map 

(OSVUM). Once issued, these designations would be made enforceable with the provisions of 

36 CFR §261.14, which prohibits the possession or operation of an OSV on National Forest System 

lands other than in accordance with the Subpart C designations. 

Designation Criteria

Background

The Travel Management Regulations set forth designation criteria that are to guide the responsible 

official’s designation of areas and trails for OSV use (see 36 CFR §212.55(a)-(e)).2 These criteria 

delineate certain elements and resources, the effects on which the responsible official must consider. 

The Travel Management Regulations at 36 CFR §212.55(a) and (b) require consideration of 

 2 Subpart C of the Travel Management Regulations incorporates the designation criteria found at 36 CFR §212.55 along with 

certain other requirements found in Subpart B. Specifically, 36 CFR §212.81(d) provides that: “the requirements governing 

designation of National Forest System roads, National Forest System trails, and areas on National Forest System lands in 

§§212.52 (public involvement), 212.53 (coordination), 212.54 (revision), 212.55 (designation criteria (including 

minimization)), and 212.57 (monitoring), shall apply to decisions made under [Subpart C].”
Over-Snow Vehicle Use Designation

Tahoe National Forest

4

enumerated “general” and “specific” designation criteria,3 whereas 36 CFR §212.55(d) and (e) 

require the responsible official to consider rights of access and wilderness areas and primitive areas in 

designating areas and trails for OSV use.

The Travel Management Regulations describe the general designation criteria (36 CFR §212.55(a)) as 

follows:

In designating National Forest System roads, National Forest System areas and trails on 

National Forest System lands for motor vehicle use, the responsible official shall consider 

effects on National Forest System natural and cultural resources, public safety, provision of 

recreational opportunities, access needs, conflicts among uses of National Forest System 

lands, the need for maintenance and administration of roads, trails, and areas that would arise 

if the uses under consideration are designated; and the availability of resources for that 

maintenance and administration.

The Travel Management Regulations describe the specific designation criteria (36 CFR §212.55(b)) 

as follows:

In addition to the criteria in paragraph (a) of this section, in designating National Forest 

System areas and trails on National Forest System lands, the responsible official shall 

consider effects on the following, with the objective of minimizing:

1) Damage to soil, watershed, vegetation, and other forest resources;

2) Harassment of wildlife and significant disruption of wildlife habitats;

3) Conflicts between motor vehicle use and existing or proposed recreational uses of 

National Forest System lands or neighboring Federal lands; and

4) Conflicts among different classes of motor vehicle uses of National Forest System 

lands or neighboring Federal lands.

In addition, the responsible official shall consider:

5) Compatibility of motor vehicle use with existing conditions in populated areas, 

taking into account sound, emissions, and other factors.

Additionally, 36 CFR §212.55(d) requires the responsible official to recognize valid existing rights of 

access in designating areas and trails for OSV use and 36 CFR §212.55(e) provides that OSV areas 

and trails shall not be designated in wilderness areas or primitive areas, “unless, in the case of 

wilderness areas, motor vehicle use is authorized by the applicable enabling legislation for those 

areas.”

Minimization Criteria

The term “minimization criteria,” refers to the subset of the specific criteria which the responsible 

official is to consider “with the objective of minimizing” the four categories of impacts set forth in 36 

CFR §212.55(b)(1)-(4) when designating areas and trails for motorized use.

 3 36 CFR §212.55(c) sets forth specific criteria for designation of roads, but because roads are not being designated as part 

of the OSV planning process, the §212.55(c) factors will not be addressed in detail in the EIS.
Revised Draft Environmental Impact Statement – Volume I

Chapter 1. Purpose and Need

Tahoe National Forest

5

The term “granular”4 refers to the degree of specificity with which the minimization criteria are 

applied. The Travel Management Regulations implement Executive Order 11644 (E.O. 11644), as 

amended by Executive Order 11989, from which the minimization criteria originate. E.O. 11644 

states that “each respective agency head shall develop and issue regulations and administrative 

instructions... to provide for administrative designation of the specific areas and trails on public 

lands on which the use of off-road vehicles may be permitted....” (emphasis added). This supports the 

application of the minimization criteria to each specific area and trail. The Ninth Circuit Court of 

Appeals has further clarified this point:

[T]he TMR requires the Forest Service to apply the minimization criteria to each area it 

designated for snowmobile use.... The TMR is concerned with the effects of each 

particularized area and trail designation. The minimization criteria must be applied 

accordingly.” WildEarth Guardians v. USFS, No. 12-35434, D.C. No. 9:10-cv-00104-DWM, 

9th Circuit Court of Appeals, 6/22/15, pp. 23 and 27 (emphasis in original).

However, it is important to note that applying the minimization criteria should not be interpreted as 

strictly requiring the prevention of all impacts. Instead, in applying the minimization criteria, the 

Forest Service maintains the flexibility to manage for a reasonable reduction of impacts while still 

addressing the need to provide areas and trails for public OSV experiences. This point is clarified in 

the preamble to the Travel Management Regulations Final Rule published on November 9, 2005:

An extreme interpretation of “minimize” would preclude any use at all, since impacts 

always can be reduced further by preventing them altogether. Such an interpretation 

would not reflect the full context of E.O. 11644 or other laws and policies related to 

multiple use of NFS lands. Neither E.O. 11644, nor these other laws and policies, 

establish the primacy of any particular use of areas and trails over any other. The 

Department believes ‘‘shall consider * * * with the objective of minimizing * * *’’ 

will assure that environmental impacts are properly taken into account, without 

categorically precluding motor vehicle use” (70 FR 68281).

Applying the General Designation Criteria

The general designation criteria were applied in the development of the proposed action are discussed 

within the effects analysis. The analysis contained in Chapter 3 analyzes the effects on natural and 

cultural resources, public safety, provision of recreation opportunities, access needs, conflicts among 

uses of National Forest System lands, the need for maintenance and administration of areas and trails 

that would arise if the uses under consideration are designated, and the availability of resources for 

maintenance and administration of OSV designations.

Applying the Minimization Criteria and Other Specific Designation Criteria

Although the Ninth Circuit Court of Appeals has referred only to the minimization criteria when 

specifying the granular application requirement, the Travel Management Regulations introduce the 

four minimization criteria together with the fifth specific criteria, which requires the responsible 

official to consider the “[c]ompatibility of motor vehicle use with existing conditions in populated 

areas, taking into account sound emissions, and other factors” 36 CFR §212.55(b)(5). Accordingly, 

this analysis treats all five specific criteria the same, considering each specific area and trail proposed 

for designation against each of the five specific criteria.

 4 Granular is used by plaintiffs to define use of minimization criteria. See United States Court of Appeals, Ninth Circuit 

Court, Wild Earth Guardians v. U.S. Forest Service, 2015, page 3 of 30.
Over-Snow Vehicle Use Designation

Tahoe National Forest

6

To apply the specific criteria in developing the proposed action and alternative actions, the forest used 

a filter system. The filter system consists of a table that crosswalks each proposed area and trail 

against each of the five specific criteria in granular fashion (see Volume II of this DEIS, Appendices 

E and F). For all specific criteria, forest resource specialists developed potential effect indicators, 

which are triggers for determining when effects to the given resources and uses set forth in 36 CFR 

§212.55(b)(1)-(5) may warrant mitigation.

In developing the proposed action, the Forest Service applied the minimization criteria (indeed, all the 

specific criteria) with full granularity. The forest developed nineteen discrete, specifically delineated 

areas on the forest for which the minimization criteria were be applied by screening the areas against 

the specific criteria (Table 2) developed with the objective of minimizing the impacts to resources. 

That is, each specific area and trail proposed for designation was considered in light of each specific 

criteria. 

The Forest was subdivided into areas to address the relationship between OSV use, resource 

protection and socio-economic factors at a smaller scale. Generally, most of these areas encompass 

major components of the groomed trail system and affected communities that rely on the activity for 

economic benefit. Other areas occur in regions of the forest that, while located adjacent to 

communities, historically exhibit adequate snowfall and opportunities for OSV recreation. 

Minimization criteria were applied individually to each area to determine the need for designating or 

not designating OSV recreation trails and areas. These criteria allowed the Responsible Official to 

weigh socio-economic concerns against resource protection issues for each area and trail

independently, and develop areas and trails for designations. 

If the resource specialists found that the potential effect indicators were not triggered for a particular 

area or trail designation, then the designation could proceed without additional mitigation. However, 

if the specialists found that a designation would trigger one or more potential effect indicators, then 

the specialists worked with the Responsible Official to identify specific mitigations that would 

address the concern. Designations of these areas and trails could proceed provided the mitigations

could be implemented. Based on application of the specific criteria, portions of the nineteen OSV use 

areas were removed from further consideration if it triggered one or more potential effect indicators 

and mitigation that would not effectively address the minimization criteria.

Table 2 captures the potential effects indicators developed to assess the areas and trails relative to 

minimization criteria. Appendices E and F document how the minimization criteria were applied on 

the Tahoe National Forest.
Revised Draft Environmental Impact Statement – Volume I

Chapter 1. Purpose and Need

Tahoe National Forest

7

Table 2. Specific (and minimization) criteria (areas and trails proposed for designation for OSV use)

1

Minimize Damage to Soil, 

Watershed, Vegetation and 

Other Forest Resources

2

Minimize Harassment of 

Wildlife and Significant 

Disruption of Wildlife 

Habitats

3

Minimize conflicts between 

motor vehicle use and existing 

or proposed recreational uses 

of NFS lands or neighboring 

Federal lands

4

Minimize conflicts among 

different classes of motor 

vehicle uses on NFS 

lands or neighboring 

Federal lands

5

Consider compatibility 

of motor vehicle use 

with existing 

conditions in 

populated areas*

• Are there potential impacts to 

soil and water from OSV use? 

Could soil be exposed during 

the times OSV use could 

occur? Is there potential for soil 

disturbance associated with 

OSV use?

• Would the area (or trail) 

contain sensitive riparian 

areas, for example wet 

meadows, bogs, fens, etc.?

• Would the area (or trail) drain 

into a 303(d)-listed waterbody?

• Does the area have a hydraulic 

mine site or sites?

• Could OSV use affect a 

municipal water system 

comprised of a small reservoir 

that goes directly into a local 

community water supply?

• Are TES plants known to occur 

in or around the trail or area 

under consideration that could 

be affected by OSV use?

• Would the area (or trail) 

include designated botanical 

areas (SIA, RNA)?

• Would the area (or 

trail) encompass 

California spotted owl, 

and/or goshawk nest 

sites? 

• Would the area (or 

trail) encompass 

sandhill crane nest 

sites?

• Would the area (or 

trail) encompass 

known bald eagle nest 

sites?

• Does the trail or area 

contain key deer winter 

range?

• Does the trail or area 

contain TES aquatic 

habitat and/or 

designated critical 

habitat?

• Would the area contain 

habitat for marten, 

wolverine, or other 

sensitive forest 

carnivores?

• Would OSV use in this area 

cause conflicts with nonmotorized visitors’ desire 

for solitude and quiet 

recreation (for example, 

PCT, Wilderness, wild & 

scenic rivers, ski areas 

(cross-country, downhill)?

• Would the area abut a 

wilderness area or National 

Park managed by other 

agencies?

• Does the area abut a nonmotorized area on adjacent 

national forest or other 

Federal lands?

• Does the area abut a 

developed recreation site 

on neighboring Federal 

lands?

• Does this area allow 

wheeled motor vehicle 

use over snow? If so, 

does this affect safety 

and winter 

management of this 

area?

• Does this area cross 

or contain plowed 

roads allowing vehicle 

use? Are road 

crossings allowed by 

OSVs?

• Does this area receive 

use by both tracked 

over-snow vehicles 

under 50 inches wide 

and over 50 inches

wide? Is this creating 

conflicts?

• Is the area adjacent 

to neighborhoods 

and communities?

• Is the area adjacent 

to recreation 

residences used 

during the winter?

If so, is OSV use of this 

area compatible with 

distinct characteristics of 

the community?

Note: Column 5 is not a minimization criteria but is required to be specifically considered by the Travel Management Regulations.

Revised Draft Environmental Impact Statement – Volume I

Chapter 1. Purpose and Need

Tahoe National Forest

9

Scope of this Action

The Tahoe National Forest Over-snow Vehicle Use Designation is not intended to be a 

comprehensive, holistic winter recreation planning effort. The decision resulting from this analysis 

would not designate National Forest System roads for public OSV use. Public OSV trails that would 

exist on snow overlaying existing National Forest System roads would be designated as National 

Forest System trails where public OSV use is allowed.

Regulating the use of wheeled, motorized vehicles or bicycles is not within the scope of this action. 

Other types of motor vehicles that may operate over snow, but do not meet the definition of an OSV, 

are regulated under Subpart B of the Travel Management Regulations. Routes and areas for these 

types of vehicles were previously designated and published on a motor vehicle use map as the result 

of a separate environmental analysis and decision.

The following uses of OSVs would be exempt from these designations and the prohibition in 36 CFR 

§261.14:

a. Limited administrative use by the Forest Service;

b. Use of any fire, military, emergency, or law enforcement vehicle for emergency purposes;

c. Authorized use of any combat or combat support vehicle for national defense purposes;

d. Law enforcement response to violations of law, including pursuit;

e. Over-snow vehicle use that is specifically authorized under a written authorization issued 

under Federal law or regulations [such as for managing permitted livestock or for access 

under a special use permit (36 CFR §212.81(a)]; and

f. Use of a road or trail that is authorized by a legally documented right-of-way held by a 

State, county, or other local public road authority (36 CFR §261.14).

Not all existing National Forest System OSV areas and trails on National Forest System lands would 

be designated for public OSV use. The agency recognizes no need to designate OSV trails, only 

identify them, in areas that would be designated as open to cross-country OSV use. It would not be 

necessary to designate an OSV trail where OSV use would not be confined to the trail. However, to 

address requirements in the Settlement Agreement with Snowlands Network et al., groomed OSV 

trails located in areas designated for OSV use will be identified.

Further, with respect to the grooming action, there are financial limitations on the miles and 

frequency of trail grooming within the forest’s snow trail grooming program. The forest’s current 

grooming program is primarily funded by the State of California Department of Parks and Recreation, 

Off-Highway Motor Vehicle Recreation (OHMVR) Division. These funds are not likely to 

substantially increase in future years.

Subpart C of the Travel Management Regulations also specifies that certain requirements of Subpart 

B of the Travel Management Regulations will continue to apply to the decision designating National 

Forest System OSV areas and trails (36 CFR 212.81(d)), including:

1. Public involvement as required by the National Environmental Policy Act (36 CFR 212.52);

2. Coordination with Federal, State, county, and other local governmental entities and tribal 

governments (36 CFR 212.53);

3. Consideration of the criteria for designation of roads, trails, and areas (36 CFR 212.55);
Over-snow Vehicle Use Designation 

Tahoe National Forest

10

4. Identification of designated uses on a publicly available use map of roads, trails, and areas (36 

CFR 212.56); and

5. Monitoring of effects (36 CFR 212.57).

The trail and area designations made as a result of this analysis would be effective immediately upon 

the issuance of the record of decision, which is expected in July, 2018. To enforce these designations, 

the Forest Service would produce an OSV use map (OSVUM) that would look similar to the existing 

motor vehicle use map (MVUM) for the Tahoe National Forest. Such a map would allow OSV 

enthusiasts to identify the routes and areas where OSV use would be allowed on the Tahoe National 

Forest.

Project Location

This proposal would be implemented on all of the National Forest System lands within the Tahoe

National Forest in northeastern California (figure 1). However, not all National Forest System trails 

and areas on these National Forest System lands would be designated for public OSV use.

Land status is correct as of April 25, 2016. Subsequently, land may be acquired or exchanged. Any 

acquired lands will be managed in accordance with Forest Plan management direction for the area 

within which they occur. Designations do not apply to private lands.
Revised Draft Environmental Impact Statement – Volume I

Chapter 1. Purpose and Need

Tahoe National Forest

11

Figure 1. Vicinity map
Over-snow Vehicle Use Designation 

Tahoe National Forest

12

Purpose and Need

One purpose of this Project is to establish designated areas and trails for OSV use on the Tahoe 

National Forest to: provide access, ensure that public OSV use occurs when there is adequate snow, 

promote the safety of all users, enhance public enjoyment, minimize impacts to natural and cultural 

resources, and minimize conflicts among the various uses of National Forest System lands.

There is a need to provide a manageable, designated OSV system of trails and areas within the Tahoe 

National Forest that is consistent with, and achieves the purposes of, the Forest Service Travel 

Management Rule at 36 CFR Part 212. This action responds to this need.

The Tahoe National Forest Land and Resource Management Plan (LRMP 1990) contains 

management area-specific standards and guidelines pertaining to public OSV use. The existing 

system of OSV trails and areas on the Tahoe National Forest is based on the LRMP’s standards and 

guidelines. Proposed changes to the existing system of OSV trails and areas have been identified, 

based on internal and public input and the Travel Management Rule’s criteria for designating roads, 

trails, and areas at 36 CFR 212.55. These changes would address needs for protecting natural 

resources, improving access for OSV users, improving quiet winter recreation opportunities, and 

ensuring consistency with LRMP management direction. Travel management decisions (including 

designating OSV areas and trails) under the 2012 Forest Service Planning Rule (36 CFR 219) are not 

forest plan decisions, but rather project-level decisions that require site-specific planning, public 

involvement, environmental analysis, and decision making (36 CFR 219.2(b)(1) and (2); Forest 

Service Handbook (FSH) 1909.12, Section 23.23a). An amendment to the Tahoe National Forest 

Land and Resource Management Plan (LRMP 1990) is needed contemporaneously with the approval 

of a decision regarding public OSV use to: (1) appropriately place planning, analysis, and decisionmaking for OSV use at the project level and (2) ensure this Project is consistent with the LRMP as 

amended (36 CFR 219.15(c)(4)).

A second purpose of this project is to comply with the Settlement Agreement between the Forest 

Service and Snowlands Network et al., by identifying those designated National Forest System snow 

trails where grooming for public OSV use would occur and analyzing the effects of the grooming 

program. Under the terms of the Settlement Agreement, the Forest Service is required to complete the 

appropriate NEPA analysis to identify snow trails available for grooming on the Tahoe National 

Forest. 

This action identifies snow trails available for grooming and addresses the need to provide a high 

quality OSV trail system on the Tahoe National Forest that is smooth and stable for the rider and 

designed so the novice rider can use these trails without difficulty.

Modified Proposed Action

Based on internal review and public comments received during the scoping period, the Forest Service 

modified its original proposed action. Mitigations to address minimization criteria for designated 

OSV areas and trails were used to modify the proposed action (appendix E and F, respectively). 

Specific actions of the modified proposed action, minimization criteria, mitigations and recommended 

monitoring are discusses in detail in chapter 2 and the appendices of this DEIS.

Decision Framework

This decision will designate snow trails and areas on National Forest System lands for OSV use on 

the Tahoe National Forest where snowfall is adequate for that use to occur. It will also identify the 

National Forest System and non-system trails where grooming for public OSV use would occur. The 
Revised Draft Environmental Impact Statement – Volume I

Chapter 1. Purpose and Need

Tahoe National Forest

13

decision would only apply to public use of OSVs as defined in the Forest Service’s Travel 

Management Regulations (36 CFR 212.1). 

Responsible Official

The Tahoe National Forest Supervisor is the deciding official who would issue the decision. The 

Forest Supervisor will consider all reasonable alternatives and decide whether to continue current 

management of public OSV uses on the Tahoe National Forest, implement the modified proposed 

action, or select an alternative for the management of public OSV uses.

Public Involvement

The interdisciplinary team relied on public involvement to ensure that a reasonable range of 

alternatives, representing a broad array of perspectives, would be analyzed in this draft environmental 

impact statement.

Scoping is a valuable step in the analysis process and is designed to share the proposed action, gather 

new information, define the overall scope of the analysis, and ultimately identify issues used to 

develop alternatives and otherwise refine the analysis. 

A scoping letter describing the proposed action and seeking public comments was sent via regular 

mail or email to approximately 812 interested groups, individuals, tribes, and agencies on 

February 20, 2015, with comments requested to be returned by March 25, 2015. A press release was 

also sent to local news media outlets on February 20, 2015. A notice of intent to prepare an 

environmental impact statement was published in the Federal Register on February 23, 2015. All 

notices included a web address for the project’s website where comments could be submitted, plus 

information on additional ways to provide comments. The project’s website could also be accessed 

from the homepage of the Tahoe National Forest’s public website, where information on the project is 

available.

Scoping letters were sent to the plaintiffs on February 20, 2015. The Forest Service discovered that it 

had inadvertently omitted some of the intervenors from its address list for the February 20, 2015, 

mailing, so scoping letters were sent to those intervenors on March 19, 2015, and they were given 

30 days to respond.

The public was invited to comment on the proposed action, identify potential conflicts or benefits, 

and provide any relevant information that would be useful in the subsequent environmental analysis. 

The Forest Service received and considered responses from 230 interested groups, individuals, and 

agencies in the form of letters, emails, and website submissions. All comments were thoughtful 

narratives reacting to the proposed action with support, opposition, concerns, or requests for revision 

and new alternatives. The Forest Service appreciates the time and perspectives shared by each 

commenter, and the willingness of all to engage in the environmental analysis process.

Public scoping meetings were held on March 2, 3, 4, 5, and 9, 2015, and were attended by interested 

and affected stakeholders and members of the public. The meetings’ objectives were to share 

information about the project’s proposed action and the NEPA process, as well as collect public input 

on the purpose and need for action. Approximately 215 people attended the five meetings. The project 

first appeared on the Tahoe National Forest’s Schedule of Proposed Actions on January 1, 2015.
Over-snow Vehicle Use Designation 

Tahoe National Forest

14

Future Administrative Review Opportunities

The Tahoe National Forest Over-snow Vehicle Use Designation is an activity implementing a land 

management plan. In addition, the action alternatives propose changes to the Tahoe National Forest 

Land and Resource Management Plan (USDA Forest Service 1990), as amended. It is not an activity 

authorized under the Healthy Forests Restoration Act of 2003 (Pub. L. 108-148). Therefore, this 

activity is subject to pre-decisional administrative review consistent with the Consolidated 

Appropriations Act of 2012 (Pub. L. 112-74) as implemented by subparts A and B of 36 CFR part 

218. The forest plan amendment portion of this project is subject to the objection regulations at 36 

CFR 219 Subpart B.

Issues

Comments that express concerns about cause-effect relationships between the proposed action and its 

effects are called “issues.” Issues serve to highlight effects or unintended consequences that may 

result from the proposed action, giving opportunities to reduce adverse effects through design 

features, mitigations, or alternatives. They are the cause-effect relationships that we identified to 

consider and analyze in depth to determine the likely impacts of each alternative. They are not the 

results of the analysis. Not all comments are issues.

Significant issues generally concern resources that may be significantly impacted by implementation 

of the proposed action and cannot be resolved through routine or standard project design features or 

mitigation measures. A significant issue is most often addressed by development and analysis of an 

alternative to the proposed action. 

An issue may be deemed a non-significant issue for any of the following reasons: (1) the issue is 

already decided by law, regulation, Forest Plan, or other higher level decision; (2) the issue is outside 

the scope of the proposed action (the issue is not part of the proposal or is not affected by it); (3) the 

issue is irrelevant to the decision to be made; and (4) the issue is conjectural and not supported by 

scientific or factual evidence. The Council on Environmental Quality 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)....”

Significant Issues

Based on the content analysis process described above, six significant issues were identified for the 

Tahoe National Forest Over-snow Vehicle Use Designation analysis. 

Quality Recreational Experiences

Non-motorized recreation.

OSV use and grooming for OSV use have the potential to impact the overall quality of the experience 

of recreationists seeking a more quiet, non-motorized experience through (1) displacing visitors who 

prefer non-motorized recreation opportunities; (2) posing safety concerns for non-motorized users due 

to the high speed of vehicles on shared trails; (3) creation of noise and air quality impacts that lead to 

the displacement of non-motorized users; (4) quickly consuming untracked powder snow, which 

reduces a desired backcountry skiing experience; (5) disrupting ski tracks, making the snow surface 

unsuitable for cross-country skiing; and (6) grooming trails, which the State of California’s Over 

Snow Vehicle Program Draft EIR estimates triples the OSV use on trails to the detriment of nonmotorized users.
Revised Draft Environmental Impact Statement – Volume I

Chapter 1. Purpose and Need

Tahoe National Forest

15

Motorized recreation experience.

Designating areas and trails for OSV use could change recreation settings and opportunities by 

enhancing opportunities for motorized winter users in some areas and limiting those opportunities in 

other areas. In the same way, OSV designations could enhance opportunities for non-motorized 

winter users in some areas, while limiting or displacing those users in other areas. 

Conflicts

Conflicts between motorized and non-motorized winter users may arise due to differing desired 

recreation experiences, public safety concerns, noise, air quality, and access issues. OSV use has the 

potential to impact designated areas that are managed for non-motorized recreation opportunities (for 

example, the Granite Chief Wilderness, North Fork American Wild and Scenic River, and Pacific 

Crest National Scenic Trail) through noise, and increased human presence. Of particular concern for 

conflicts between motorized and non-motorized winter recreationists are areas that can be accessed in 

the winter from the Forest’s six winter trailheads: Yuba Gap, Donner Summit, Yuba Pass, Little 

Truckee Summit, Bassett’s, and China Wall. Most winter recreationists (both motorized and nonmotorized) launch their winter recreation activities from these six designated winter trailheads.

For this analysis, quality recreation experiences are defined as the forest’s most popular winter 

recreation activities, according to the National Visitor Use Monitoring Report (USDA Forest Service 

2005, 2010, 2015) along with the importance of motorized and non-motorized winter recreation 

opportunities as described in the Recreation Facility Analysis Niche Statements (USDA Forest 

Service 2007).

Measurement indicators for determining effects to motorized and non-motorized recreation settings, 

recreation opportunities, quality experiences, and conflicts between motorized and non-motorized 

winter users are described in Chapter 3, Recreation Resource section in table 19.

Noise

OSVs traveling in designated areas and on designated trails and machines e grooming OSV trails 

could generate anthropogenic (human-caused) noise and increase noise levels in the short term above 

ambient levels. This has the potential to adversely impact wildlife species that are sensitive to this sort 

of disturbance as well as the experience of the recreational user who values solitude and quiet 

recreational opportunities. 

The noise model inputs will consider the proximity of predicted noise increases above ambient levels 

in sensitive areas to include:

♦ Points on the Pacific Crest Trail;

♦ Trails near wilderness areas;

♦ Trails near communities;

♦ Trails brought forward by the public as concern areas during scoping;

♦ Wildlife concern areas.

Measurement indicators for determining effects of noise are described in Chapter 3, Noise Resource 

section in table 34.
Over-snow Vehicle Use Designation 

Tahoe National Forest

16

Air Quality

OSVs traveling on designated trails and in designated areas and machines grooming OSV trails could

generate exhaust and emit pollutants into the air, and possibly degrade the quality of the air. This 

potential degradation of air quality could impact recreational users, wildlife, and sensitive areas. 

There are no measurement indicators for determining effects to air quality. Only a qualitative 

discussion of the potential contribution of OSV emissions from the estimated number of visitors to 

the Tahoe National Forest each year will be described.

Water and Soil Resources

OSV use may result in ground disturbance and snow compaction, and this could directly, indirectly 

and/or cumulatively adversely impact soil and water resources through soil compaction, erosion, and 

displacement. These possible impacts to soils could then indirectly result in adverse impacts to plants 

due to changes in soil temperature and productivity. In addition, changes in snowmelt patterns could 

affect hydrologic regimes in localized areas. It is also possible that public OSV use could directly 

damage riparian and wetland vegetation. Public OSV use could also release burned and unburned fuel 

and lubricants into the environment. These potential impacts can then indirectly result in adverse 

impacts to water quality and alter snowmelt patterns. 

OSVs, when operating cross country instead of on trails, can disturb the ground, if snow depth and 

density are insufficient, and create widespread impacts. These possible effects are highly dependent 

on location, particularly in areas of thin snow cover, and the amount and timing of use. 

OSVs, when operating on trails without adequate snow depth have the potential to also result in soil 

compaction, erosion, and displacement, and decreased water quality, as described above.

Measurement indicators for determining effects to soil and water resources are described in Chapter 

3, Hydrology and Soils Resource sections in table 51 and table 60.

Terrestrial Wildlife

OSV use and grooming of OSV trails could impact terrestrial wildlife through direct injury, mortality, 

or disturbance to individuals (e.g., increased noise and human presence resulting in a loss of breeding 

and/or feeding) and modifications of wildlife habitats (e.g., alteration of competitor/predator 

communities).

OSVs, when operating cross country instead of on trails, can impact wildlife species as snow is 

compacted in areas of inadequate snow cover, in addition to subnivean (i.e., the zone in and under the 

snow) habitat for small mammals. These potential effects are highly dependent on location, 

particularly areas of inadequate snow cover, and the amount and timing of use.

Resource indicators and measures for this issue are shown in Chapter 3, Terrestrial Wildlife in table 

63.

Aquatic Wildlife

OSV use and grooming for OSV use have the potential to impact aquatic wildlife species (fish and 

amphibians) and their habitats in the project area through: (1) direct disturbance to species when OSV 

use occurs in wet meadows, streams, and/or other sensitive habitats; (2) indirectly through generation 

of exhaust and associated pollutants in or near aquatic species habitat, which can degrade water 

quality; (3) indirectly through release of fuel or other pollutants during refueling and proximity to 
Revised Draft Environmental Impact Statement – Volume I

Chapter 1. Purpose and Need

Tahoe National Forest

17

aquatic species habitats, which can degrade water quality; and (4) indirectly through increased soil 

erosion in marginal snow depth areas.

Over-snow vehicles, when operated cross country instead of on designated trails, may create more 

widespread impacts due to the potential for soil compaction and soil erosion. These possible effects 

are highly dependent on location, amount of snow cover, and amount and timing of use.

Over-snow vehicles, when operated on designated National Forest System roads and designated 

National Forest System trails without adequate snow cover, could also result in soil compaction, 

erosion, and displacement, and decreased water quality, as described above. These potential impacts 

to soil and water resources can indirectly affect riparian habitats and aquatic habitats, if in close 

proximity to these trails.

Resource indicators and measures for this issue are shown in Chapter 3, Aquatic Resource section in

table 87.

Other Relevant Resources Topics (Non-significant Issues)

Other relevant resources are not significant issues, and therefore, not necessarily critical to the 

analysis, but are helpful in understanding the full extent of the alternatives. Other relevant resources 

provide additional information for the analysis, but do not necessarily drive the formulation of 

alternatives. They are of interest in terms of minimizing impacts. It is anticipated that when project 

design features and mitigating measures are implemented, the resulting effects to each of the 

following resources would be imperceptible, or if perceptible (meaning, “if it occurs in some 

perceptible intensity”), meaningless when considered in the appropriate context. Analysis was

conducted to identify and disclose how the minimization criteria were considered and evaluated for 

effectiveness (36 CFR 212.55(b)).The responsible official and interdisciplinary team reviewed public 

and internal scoping to date and law, regulation, and policy to determine other relevant resources. We 

identified the following relevant resources for the Tahoe National Forest OSV use designation 

analysis.

Botany

Designating areas and trails for public OSV use and grooming trails for public OSV use has the 

potential to (1) impact woody species that extend above the snow cover; (2) impact plant composition 

and habitat suitability; (3) impact plants under the snow when there is less than adequate snow cover; 

and (4) transport non-native invasive plant seeds into new areas.

The potential for impacts to botanical resources are influenced by snow depth, season of use, and 

proximity to groomed and ungroomed trails where public OSV use would occur.

Resource indicators and measures for this issue are shown in Chapter 3, Botany Resource section in

table 94.

Socioeconomics

Designating areas and trails for public OSV use and changes in areas available for public OSV use 

and non-motorized use may impact the local economy (economic contributions of winter recreation 

on National Forest System lands) and could result in social consequences (including quality of life 

and local lifestyles). In addition to economic impacts, management actions affecting over-snow 

vehicle use on National Forest System lands may also have social consequences. Social impacts will 

be considered qualitatively, including how management actions may affect traditional and cultural ties 

to Federal lands within the area of influence.
Over-snow Vehicle Use Designation 

Tahoe National Forest

18

Minority and low-income populations within the area of influence that qualify as Environmental 

Justice populations will also be identified to determine if disproportionately high adverse human 

health or environmental effects would result from proposed actions.

Resource indicators and measures for this issue are shown in Chapter 3, Socioeconomic Resource 

section in table 110.

Cultural Resources

In all of the alternatives, the types of management activities proposed could directly, indirectly, or 

cumulatively affect cultural resources and are subject to the regulations outlined in Section 106 of the 

National Historic Preservation Act , as amended and as promulgated by 36 CFR Part 800, to address 

those effects to cultural resources. A qualitative discussion of the effects to cultural resources in areas 

designated for OSV use will be described.

Transportation and Engineering

This analysis evaluates possible effects to engineering and roads, including safety, traffic, 

affordability, jurisdiction, and the underlying forest transportation system. 

Effects on public safety and traffic will be evaluated by considering the interface between motor 

vehicle operators and other users of the trail systems. Cost and affordability will be evaluated in terms 

of changes to the total cost of maintaining the Tahoe National Forest transportation system that would 

be open to motor vehicle use. This analysis would not involve standard (wheeled motor vehicle) road 

maintenance costs. The effects to the underlying National Forest System roads and trails, including 

wear and tear that may affect wheeled motor vehicle use would also be evaluated. Mitigations and 

monitoring procedures have been identified for all of the action alternatives to minimize these 

possible impacts. 

Climate Change

OSV use and grooming of OSV trails could contribute to greenhouse gas emissions via OSV exhaust 

and release of these pollutants into the air. The air quality analysis will consider these emissions and 

provide information for the EIS related to the differences between the alternatives regarding overall 

air quality. 

However, preliminary analysis indicates that while localized air quality may be degraded in some 

site-specific locations based on concentrated OSV use in specific popular motorized recreation areas, 

it is unlikely to contribute in any measureable way to regional levels. For this reason, the impact of 

the project on climate change will not be considered further in the analysis. 
Draft Environmental Impact Statement – Volume I

Chapter 2. Alternatives

Tahoe National Forest

19

Chapter 2. Alternatives

Introduction

This chapter describes and compares the no-action alternative and four action alternatives for the 

Tahoe National Forest Over-snow Vehicle Use Designation. It includes a detailed description and 

maps (located in the map package) of each alternative and alternatives considered, but eliminated 

from detailed study; and presents the alternatives in comparative form, sharply defining the 

differences between alternatives and providing a clear basis for choice among options by the decision 

maker and the public. Numbers such as acres and miles are approximate due to the use of GIS data 

and rounding.

Areas Considered for OSV Use Designation

The Tahoe National Forest Land and Resource Management Plan, as amended, uses standards and 

guidelines to establish OSV use designations on 109 management areas across the forest. However, 

for this planning effort, the Tahoe National Forest has delineated 21 discrete specific areas considered 

for OSV use designation, within the administrative boundaries of the Tahoe National Forest. Each 

area considered for OSV use is smaller than a ranger district, consistent with 36 CFR 212.1. Two of 

these areas will not be considered for OSV designation under any of the alternatives. Granite Chief 

Wilderness which was designated by Congress as non-motorized, and North Fork American Wild and 

Scenic River which is not for motorized use as stated in the Forest Plan (LRMP, pg. V-429 and 452). 

The remaining 19 areas considered for OSV use designation (see table 3 for a list of all areas, and 

figure 2 in the map package) have been reviewed for consistency with the Travel Management Rule’s 

designation criteria (36 CFR 212.55). Each alternative proposes designating varying portions of these 

19 areas for public cross-country OSV use. These areas are primarily bounded by ridge tops, roads, or 

other geographic features that allow each area to be readily distinguished. They are also defined by 

their proximity to access points and communities that are socially and economically tied to OSV use 

and other types of winter recreation.

Designated Trails

Each alternative proposes specific National Forest System roads and trails to be designated as OSV 

trails (see table 4 for a full list of trails) for public OSV use. Designated OSV trails have been 

reviewed for consistency with the Travel Management Rule’s designation criteria (36 CFR 212.55). 

OSV trail segments and mileages vary by alternative.

Three types of OSV trails are discussed in this document.

Designated OSV Trails Available for Grooming

The grooming season generally begins in mid-December and continues through March. Start 

and stop times vary per trail location and are dependent upon the presence and depth of snow. 

Trails are prioritized for grooming based on visitor use. Grooming has historically occurred 

several times per week on priority trails and after major storms. 

Trails would be groomed for public OSV use to a minimum width of 10 feet and typically 

14 feet wide. Groomed trail width is determined by a variety of factors such as width of the 

underlying road bed, width of grooming tractor, level of use, and to minimize use conflicts. 

Snow trails would not be groomed beyond the width of the underlying roadbed, where one 
Over-snow Vehicle Use Designation 

Tahoe National Forest

20

exists. Where the terrain allows, main ingress and egress snow trails that connect to the 

trailhead would be groomed to 18 feet wide or greater to facilitate the added traffic.

Snow trail grooming for public OSV use would be conducted in accordance with the 1997 

Snowmobile Trail Grooming Standards set by the California Off-Highway Motor Vehicle 

Recreation (OHMVR) Division. The California OHMVR Division’s snowcat fleet is subject 

to emission regulation by the California Air Resources Board (CARB) as off-road equipment. 

The CARB sets an emission limit for the vehicle fleet as a whole rather than for individual 

pieces of equipment.

• Marked, Ungroomed OSV Trails

These trails are identified, not designated, in areas designated for OSV cross-country use, 

where OSV use is not confined to the trail. 

• Designated OSV Trails Not Available for Grooming

These trails are designated for OSV use and not available for grooming. Often, they are 

linkages between parking areas and trailheads to designated OSV cross-country use areas.

Vehicle Class

An OSV is defined as a motor vehicle that is designed for use over snow and that runs on a track or 

tracks and/or a ski or skis, while in use over snow (36 CFR 212.1). This broad definition includes a 

wide range of vehicles, from snow bikes to highway-legal vehicles equipped with tracks. Subpart C of 

the Forest Service’s Travel Management Regulation at 36 CFR Part 212 allows for designation by 

class of vehicle. To provide a safe and enjoyable recreation experience, as well as to protect 

resources, two different OSV classes are discussed in the action alternatives: 

• Class 1: over-snow vehicles 50 inches or less in width at the widest point on the vehicle; and 

• Class 2: over-snow vehicles more than 50 inches in width at the widest point on the vehicle.

Forest Plan Amendment 

A forest plan amendment would be needed under all of the action alternatives (Alternatives 2, 3, 4, 

and 5). The proposed amendment to the forest plan, common to all of the action alternatives, would 

remove Tahoe National Forest Land and Resource Management Plan (LRMP 1990) OSV use 

standards and guidelines for each management area, and replace them with the following forest-wide 

standard: “Manage over the snow vehicle (OSV) use through designation of routes and trails 

consistent with travel management regulations.”

Designating OSV areas and trails under the Travel Management Rule is not a land management plan 

decision, but rather a project-level decision that requires site-specific planning and analysis (36 CFR 

219.2(b)(1) and (2); FSH 1909.12, Section 23.23a). Under this amendment, specific trail and area 

designations for public OSV use would be appropriately proposed and analyzed, with decisions made,

at the project level. Any and all OSV use designations would require project-level environmental 

analysis and decision-making with public involvement as required by the National Environmental 

Policy Act (NEPA). The proposed change to the LRMP would be consistent with the 2012 Planning 

Rule’s stated levels of planning at 36 CFR 219.2 in which forest plans do not authorize activities or 

projects, nor do they make commitments for taking site-specific actions. Rather, forest plans provide 

the sideboards for future site-specific actions (36 CFR 219.2(b)(1) and (2)). 

In accordance with 36 CFR Part 219.13(b)(5), the responsible official must determine: (1) which specific 

substantive requirement(s) within 36 CFR 219.8 through 219.11 are directly related to the plan 

direction being added, modified, or removed by the amendment and (2) apply such requirement(s) 
Draft Environmental Impact Statement – Volume I

Chapter 2. Alternatives

Tahoe National Forest

21

within the scope and scale of the amendment. The substantive requirements address sustainability (36 

CFR 219.8), diversity of plant and animal communities (36 CFR 219.9), multiple use (36 CFR 

219.10), and timber requirements based on the NFMA (36 CFR 219.11). The responsible official is 

not required to apply any substantive requirements that are not directly related to the amendment. The 

Responsible Official has determined the proposed plan amendment is directly related to 36 CFR 219.10 

Multiple Use, (a)(1) recreation settings and opportunities. 

Monitoring

Recreation staff and law enforcement and investigations officers regularly monitor winter trailheads, 

trails and other areas during the OSV season. Recreation staff and law enforcement officers use trail 

patrols (via snowmobiles, skis or snowshoes) and communication with visitors and other staff (such 

as the groomers) to gain an understanding of the changing conditions on the Forest throughout the 

winter. 

Wilderness boundaries and other areas not designated for OSV use near designated OSV trails and 

areas would be visited by Forest Service staff throughout the OSV season to determine if OSV 

incursions have occurred. Trailheads and groomed trail areas would be visited and assessed for user 

conflicts and public safety concerns. Designated OSV trails would be visited to ensure public OSV 

use is not encroaching outside the trail corridor in areas where such use was not designated. If 

concerns related to these issues arose, site-specific controls (such as speed limits, segregated access 

points for motorized and non-motorized use, increased visitor information, or increased on-site 

management presence) would be coordinated and implemented as necessary. 

Compacted snow on road surfaces resulting from OSV use and grooming may increase road drainage 

needs. Impacts to watershed resources would be minimized by periodically visually monitoring native 

surface roads used as OSV trails during spring runoff to determine if additional road drainage is 

needed. Visual Monitoring of wet meadow areas, trail stream crossings, hill climb areas and other 

areas with sensitive resources and/or concentrated use would occur when snow depth is less than 24 

inches periodically to determine if resource damage was occurring, which could prompt corrective 

actions. 

How Alternatives were Developed

Five alternatives were developed to address the significant isssues raised during scoping and detailed 

in Chapter 1 of this DEIS.

The no-action alternative (alternative 1) represents the current management of the OSV program on 

the Tahoe National Forest as described in the Tahoe National Forest Land and Resource Management 

Plan (LRMP, 1990), as amended. 

The proposed action (alternative 2), as originally described in the February 23, 2015 Notice of Intent, 

responds primarily to the quality recreational experience by balancing motorized and non-motorized 

opportunities. The Forest Service modified the original proposed action based on scoping input 

received from the public, taking into account where most visitors need to drive and park to access 

winter recreation opportunities on the Forest, as well as elevations where snowfall is adequate for 

OSV use to occur (36 CFR 212.81(a)). Further, scoping input was combined with the Travel 

Management Rule’s designation criteria (36 CFR 212.55) to propose and evaluate the proposed 

action’s OSV trail and area designations. The Forest Service applied the Travel Management Rule’s 

specific criteria at 36 CFR 212.55(b) using a route-by-route and area-by-area approach, which is 

documented in Volume 2 of this DEIS, Appendices E and F.
Over-snow Vehicle Use Designation 

Tahoe National Forest

22

After reviewing scoping comments the original proposed action was modified with the following 

changes:

• The original proposed action described National Forest System areas and trails as open, 

closed, or prohibited. The Final Rule for Subpart C of the Forest Service’s Travel 

Management Regulations (36 CFR Part 212) became effective on February 27, 2015. Due to 

the timing of the release of the Final Rule and the NOI, the NOI proposed action used the 

Proposed Rule, dated June 18, 2014, which stated: “Designation of a National Forest System 

road, National Forest System trail, or area on National Forest System lands where over-snow 

vehicle use is allowed, restricted, or prohibited pursuant to § 212.81 on an over-snow vehicle 

use map.” The final rule, states: “Designation of a National Forest System road, a National 

Forest System trail, or an area on National Forest System lands where over-snow vehicle use 

is allowed pursuant to § 212.81.” The modified proposed action in this DEIS (Alternative 2) 

uses the Final Rule’s approach of designating areas and trails for OSV use.

• The Forest Service has authority from Placer County to control and maintain the seasonally 

closed portion of Foresthill Road (G0088) and its right-of-way for snow recreation purposes 

starting at China Wall. This was not reflected in the Proposed Action/Notice of Intent, but is

incorporated in this process going forward.

• Generally, areas below 5,000 feet elevation would not be designated for public OSV use. No 

key deer winter range would be designated for OSV use, except for the lower section of the 

Mosquito Ridge Trail.

• OSVs would be classified into two classes of vehicle, with restrictions on Class 2 vehicles.

• Snow depth requirements were clarified to reflect resource damage concerns.

• A rerouted section of the PCT in the Packer Lake area was completed after the original 

proposed action was released. The modified proposed action reflects the new PCT alignment.

Alternative 3 was submitted by Snowlands Network and others during scoping to respond to issues

surrounding (1) the quality and quantity of non-motorized winter recreational opportunities available 

on the Forest; (2) the potential for OSV trail grooming and OSV noise to adversely impact quiet 

recreation experiences and disturb wildlife; and (3) air quality impacts, particularly localized impacts 

to those desiring a non-motorized winter recreation experience. This alternative would designate less 

acreage for OSV use across the Forest, with an emphasis on providing greater non-motorized winter 

recreation opportunities compared to current management. This alternative would designate existing 

popular OSV cross-country areas and trails on the Forest for public OSV use. 

Alternative 4 was developed with input from the Blue Ribbon Coalition and other OSV enthusiasts. 

This alternative emphasizes providing opportunities for winter motorized recreationand provides

slightly more opportunities for public OSV user compared to current management (Alternative 1).

Alternative 5 responds to public comments concerning potential impacts on wildlife and natural 

resources from OSV use. It would provide less designated acreage for OSV use, and therefore, fewer 

opportunities for motorized winter recreation experiences on the Forest to emphasize protection of 

wildlife and other forest resources. In addition, Alternative 5 would provide greater opportunities for

non-motorized winter recreation activities compared to Alternatives 1, 2, and 4.

Alternatives Considered in Detail

The Forest Service explored and evaluated five alternatives (all are summarized and compared in the 

“Comparison of Alternatives” section at the end of this chapter).
Draft Environmental Impact Statement – Volume I

Chapter 2. Alternatives

Tahoe National Forest

23

Alternative 1: No Action (Continue Current Management)

The no-action alternative is required under NEPA regulations [40 CFR §1502.14(d)]. This alternative 

represents the existing baseline condition or trends by which the action alternatives are compared. 

Under this alternative, the Forest Service would follow the OSV use designations for each 

management area in the Tahoe National Forest Land and Resource Management Plan (LRMP 1990), 

as amended (Volume II of this DEIS, Appendix B). No changes would be made to the Forest Plan’s

OSV use designations within the Tahoe National Forest except as prohibited by Forest Order.

Under alternative 1, public OSV use designations on the approximately 836,273-acre Tahoe National 

Forest would be managed in accordance with existing Forest Plan direction as follows:

• Approximately 636,002 acres of National Forest System lands are designated for public 

cross-country OSV use (table 3).

• Approximately 1,218 acres of National Forest System lands are designated for public crosscountry OSV use in deer holding areas from January 1 through September 14 (LRMP, pg. V30). 

• The Forest Plan does not establish a minimum snow depth for trail or cross-country public 

OSV use.

• The Tahoe National Forest has a total of approximately 265 miles of designated OSV trails. 

Approximately 217 miles of designated OSV trails are available for grooming and 41 miles 

of marked, ungroomed trails for OSV use are located within areas designated for OSV use. 

Approximately 7 miles of designated OSV trails are not available for grooming (table 4,

figure 2 located in the map package).

• The Forest Plan does not provide specific management direction for OSV trail grooming 

activities; however, the forest follows the California State Parks’ Off-Highway Motor Vehicle 

Recreation Division snow depth standards for grooming, currently 12 to 18 inches of snow.

• Approximately 99 miles of the PCT traverse the Tahoe National Forest. Of that, 76 miles of 

the PCT is on National Forest System lands. OSV use on the PCT is prohibited by the 

National Scenic Trails Act, P.L 90-543, Section 7(c).

• There are no designated OSV crossings of the PCT.

Alternative 1 is summarized in table 3 and table 4 and displayed in figure 2 located in the map

package.

Table 3. OSV use designations - alternative 1

Areas Considered for OSV Use 

Designation

Area Size

(Total Acres)

OSV Designated Use

(Acres)

Barker 9,847 9,783

Black Buttes 41,252 39,592

Bowman 19,604 18,033

Donner Summit 11,634 9,052

Foresthill East 90,992 90,391*

Foresthill North 36,151 34,026

Foresthill West 32,957 26,482
Over-snow Vehicle Use Designation 

Tahoe National Forest

24

Areas Considered for OSV Use 

Designation

Area Size

(Total Acres)

OSV Designated Use

(Acres)

Lafayette 46,807 41,210

Reservoirs 40,883 40,883

Sierraville East 75,557 55,375

Sierraville North 17,564 17,564

Sierraville West 96,311 95,214

South of 20 17,346 10,078

Summit West 15,560 4,466

Truckee 34,446 21,356

Yuba NE 83,273 72,566

Yuba NW 43,255 37,717

Yuba South 20,657 14,140

Yuba West 40,708 76

* Public OSV use is allowed between January 1 and September 14 for 1,218 acres.

Table 4. OSV Trails – alternative 1

Designated OSV Trails Available for Grooming Trail Length

(Miles) Areas

American Hill Trail 9.51 Foresthill East

Bald Ridge Loop Trail 14.40 Sierraville West

Bowman Trail 13.60 Bowman

Duncan “Y” Trail 5.14 Foresthill East

Fifty-Four Road Trail 12.54 Sierraville West

Yuba NE

Ford Point Trail 1.68 Foresthill East

Foresthill Divide Trail 14.21 Foresthill East

Haskell Peak Trail 15.55 Yuba NE

Howard Trail 5.40 Yuba NE

Humbug Tie Trail 0.82 Foresthill East

Humbug Trail 4.66 Foresthill East

Independence Lake Loop Trail 1.98 Sierraville West

Truckee

Jackson Meadow Little Truckee Trail 14.61 Sierraville West

Lower Ford Point Trail 1.30 Foresthill East

Meadow Lake Loop Trail 6.18 Sierraville West

Mosquito Ridge Trail 6.78 Foresthill East

Pass Creek Loop Trail 7.58 Sierraville West

Prosser Creek CNNTR Trail 13.35 Sierraville West

Prosser Hill Winter Trail 1.05 Sierraville West

Rattlesnake Trail 10.10 Black Buttes

Ridge Loop Trail 6.05 Sierraville West

Rim Loop Trail 2.84 Sierraville West

Robinson Flat Trail 1.27 Foresthill East

Sawtooth Trail 1.21 Truckee
Draft Environmental Impact Statement – Volume I

Chapter 2. Alternatives

Tahoe National Forest

25

Designated OSV Trails Available for Grooming Trail Length

(Miles) Areas

Soda Springs Trail 6.36 Foresthill East

Sterling Trail 2.30 Black Buttes

Tadpole Trail 3.01 Foresthill East

Treasure Mtn Loop Trail 16.17 Sierraville West

Yuba Webber Trail 17.00 Sierraville West

Yuba NE

Total 216.65

Marked, Ungroomed Trails for OSV Use

Andesite West OSV Trail 2.47 Donner Summit

Summit West

Gold Valley Trail 11.46 Yuba NE

Mosquito Ridge Trail 21.11 Foresthill East

Sawtooth Trail 6.22 Truckee

Total 41.25

Designated OSV trails not Available for Grooming

Andesite West OSV Trail 1.00 Donner Summit

Gold Valley Trail 1.18 Yuba NE

Martis Peak Trail 1.81 Truckee

Mosquito Ridge Trail 0.27 Foresthill East

Sawtooth Trail 2.81 Truckee

Total 7.06
Over-snow Vehicle Use Designation 

Tahoe National Forest

26

Alternative 2: Modified Proposed Action (Preferred Alternative)

The following, along with mitigations in Appendices E, and F, respectively describes how the Forest 

Service would manage public OSV use on the Tahoe National Forest under the modified proposed 

action:

• Approximately 406,895 acres of National Forest System lands would be designated for public 

cross-country OSV use, generally above 5,000 feet elevation (table 5, figure 3 in the map 

package). 

• Public OSV use would not be designated in a 1-acre area near Robinson Flat to protect historic 

structures.

• Individual parcels of National Forest System lands currently under long-term special use permits 

for Royal Gorge Cross Country Ski Area, Tahoe Donner Cross Country Ski Area, Boreal Ski 

Area, Donner Ski Ranch Ski Area, Sugar Bowl Ski Area, Alpine Meadows Ski Area and Squaw 

Valley Ski Area would not be designated for public OSV use.

• Implement forestwide snow depth requirements for public OSV use by:

• Allowing public, cross-country OSV use in designated OSV areas only when there is 

adequate snow depth to avoid damage to natural and cultural resources. To avoid 

damaging resources, a minimum of 12 inches of uncompacted snow is typically needed. 

On designated OSV trails with underlying roads, a minimum of 6 inches is typically 

needed to avoid damage to the underlying road surface; and

• Following California State Parks’ Off-Highway Motor Vehicle Recreation Division snow 

depth standards for grooming, currently 12 to 18 inches of snow.

• Class 1 OSVs are allowed on all designated OSV trails and areas. Class 2 OSVs are only allowed 

on designated OSV trails available for grooming. Class of vehicle definitions can be found on 

page 2.

• Approximately 237 miles of designated OSV trails are available for grooming. Approximately 14 

miles of marked, ungroomed trails are located within areas designated for cross-country OSV use. 

Approximately 70 miles of designated OSV trails are not available for grooming (table 6, figure 3 

in the map package).

• There would be 22 designated OSV crossings of the PCT (table 7, figure 3 in the map package). 

• Thirteen designated crossings would utilize roads identified on the Tahoe National 

Forest’s Motor Vehicle Use Map and would be the width of the road (approximately 14 

feet). 

• Nine proposed OSV crossings of the PCT would not utilize roads and would range in 

width up to 0.25 miles. These crossings are located in areas where OSV use is designated 

on either side of the PCT. OSV users would need a way to get across the Trail as OSV use 

along the PCT is prohibited by the National System Trails System Act, P.L 90-543, Section 

7(c). Some of these proposed OSV crossings are wider than the width of a road because 

they are located in areas where snow conditions are highly variable during the course of a 

winter, for example areas prone to wind loading of snow and formation of cornices. These 

wider crossings give OSV users options to select a safe crossing of the Trail under 

constantly changing, variable snow loading conditions. In all cases, OSVs crossing the 

PCT would do so at 90 degrees to minimize the time and distance needed to cross the 

Trail. There is one exception, where the current alignment of the PCT overlays the Pass 
Draft Environmental Impact Statement – Volume I

Chapter 2. Alternatives

Tahoe National Forest

27

Creek Loop OSV Trail on Forest Service Road 70 for approximately 700 feet. In this 

place, OSVs are not required to cross the PCT at 90 degrees because the PCT and the 

Road alignment currently share the same footprint.

Alternative 2 is summarized in table 5, table 6, and table 7 and displayed in figure 3 located in the 

map package.

.

Table 5. OSV use designations under alternative 2

Areas Considered for OSV Use 

Designation

Area size

(Total Acres)

OSV Designated Use

(Acres)

Barker 9,847 9,783

Black Buttes 41,252 37,816

Bowman 19,604 10,966

Donner Summit 11,634 8,034

Foresthill East 90,992 54,585

Foresthill North 36,151 22,987

Foresthill West 32,957 0

Lafayette 46,807 14,183

Reservoirs 40,883 36,998

Sierraville East 75,557 29,004

Sierraville North 17,564 4,111

Sierraville West 96,311 93,050

South of 20 17,346 4,246

Summit West 15,560 0

Truckee 34,446 9,259

Yuba NE 83,273 54,588

Yuba NW 43,255 15,268

Yuba South 20,657 1,750

Yuba West 40,708 267

Table 6. OSV Trails– alternative 2

Designated OSV Trails Available for Grooming Trail Length

(Miles) Areas

American Hill Trail 9.51 Foresthill East

Bald Ridge Loop Trail 14.40 Sierraville West

Bowman Trail 13.60 Bowman

Duncan “Y” Trail 5.14 Foresthill East

Fifty-Four Road Trail 12.54 Sierraville West

Yuba NE

Ford Point Trail 1.68 Foresthill East

Foresthill Divide Trail 14.21 Foresthill East

Haskell Peak Trail 15.55 Yuba NE

Howard Trail 5.40 Yuba NE
Over-snow Vehicle Use Designation 

Tahoe National Forest

28

Designated OSV Trails Available for Grooming Trail Length

(Miles) Areas

Humbug Tie Trail 0.82 Foresthill East

Humbug Trail 4.66 Foresthill East

Independence Lake Loop Trail 1.98 Sierraville West

Truckee

Jackson Meadow Little Truckee Trail 14.61 Sierraville West

Lower Ford Point Trail 1.30 Foresthill East

Meadow Lake Loop Trail 6.18 Sierraville West

Mosquito Ridge Trail 28.16 Foresthill East

Pass Creek Loop Trail 7.58 Sierraville West

Prosser Creek Trail 13.35 Sierraville West

Prosser Hill Winter Trail 1.05 Sierraville West

Rattlesnake Trail 10.10 Black Buttes

Ridge Loop Trail 6.05 Sierraville West

Rim Loop Trail 2.84 Sierraville West

Robinson Flat Trail 1.27 Foresthill East

Soda Springs Trail 6.36 Foresthill East

Sterling Trail 2.30 Black Buttes

Tadpole Trail 3.01 Foresthill East

Treasure Mtn Loop Trail 16.17 Sierraville West

Yuba Webber Trail 17.00 Sierraville West

Yuba NE

Total 237.04

Marked, Ungroomed Trails for OSV Use

Andesite West OSV Trail 1.68 Donner Summit

Summit West

Gold Valley Trail 12.64 Yuba NE

Total 14.32

Designated OSV trails not Available for Grooming

Andesite West OSV Trail 1.79 Donner Summit

Summit West

Bear Valley 6.52 Sierraville East

CAL IDA Scales 14.86 Yuba NW

Carmen Valley 8.06 Sierraville North

Carmen Valley Spurs 1.7 Sierraville North

Eureka 6.49 Yuba NW

Frosty East 5.01 Sierraville North

Martis Peak Trail 1.81 Truckee

Mosquito Ridge 18.72 Foresthill East

Foresthill West

North Tie 0.05 Sierraville North

Sawtooth OSV Trail 1.40 Truckee

Texas Hill/Mears 3.83 Foresthill North

Un-named (Boy Scout Camp to Yuba River) 0.56 Yuba NE
Draft Environmental Impact Statement – Volume I

Chapter 2. Alternatives

Tahoe National Forest

29

Designated OSV Trails Available for Grooming Trail Length

(Miles) Areas

Total 70.24

Table 7. Designated Pacific Crest Trail OSV crossings (displayed from south to north) – alternative 2

Designated Pacific Crest Trail OSV Crossing Area

• 16E75 (Rubicon Jeep) Barker

• 0003-004 (Niehaus) Barker

• 0003 (Barker Pass) Barker

• T.18N., R.14E.,22 Sierraville West

• 0086 (Meadow Lake) Sierraville West

• 0070-040-20 (Moscove Spur) Sierraville West

• 0070-040 (Moscove) Sierraville West

• 0070-065 (Jackson Overlook) Sierraville West

• 0070 (Pass Creek Loop) Sierraville West

• 0007 (Fibreboard) Sierraville West

• 0093-002-03 (Monarch Spur) Yuba NE

• T.20N., R.12E.,08 Yuba NE

• T.20N., R.12E.,05 Yuba NE

• T.21N., R.12E.,29, 30 Yuba NE

• T.21N., R.12E.,19 Yuba NE

• T.21N., R.12E.,19 Yuba NE

• T.21N., R.12E.,18 Yuba NE

• T.21N., R.11E.,13 Yuba NE

• T.21N., R.11E.,11 Yuba NE

• T.21N., R.11E.,02 Yuba NE

• 11E68 (Lavezzola Creek OHV Trail) Yuba NE

• 2308-001 (Cowell Mine Rd.) Yuba NE

.

Alternative 3

This alternative addresses issues related to quality and quantity of non-motorized winter recreational 

opportunities, noise impacts from OSV use, and air quality impacts from OSV use by emphasizing 

providing opportunities for non-motorized winter recreation across the Forest. The following 

summarizes how the Forest Service would manage public OSV use on the Tahoe National Forest 

under this alternative:

• Approximately 275,972 acres of National Forest System lands would be designated for public 

cross-country OSV use (table 8 and figure 4 in the map package).

• Approximately 1,408 acres of National Forest System lands are designated for public 

cross-country OSV use in deer holding areas from January 1 through September 14 (LRMP, page 

V-30).
Over-snow Vehicle Use Designation 

Tahoe National Forest

30

• Public OSV use would not be designated in a 1-acre area near Robinson Flat to protect historic 

structures.

• Individual parcels of National Forest System lands currently under long-term special use permits 

for Royal Gorge Cross Country Ski Area, Tahoe Donner Cross Country Ski Area, Boreal Ski 

Area, Donner Ski Ranch Ski Area, Sugar Bowl Ski Area, Alpine Meadows Ski Area and Squaw 

Valley Ski Area would not be designated for public OSV use.

• Cross-country OSV use would be designated during specific dates in aquatic and terrestrial 

wildlife species’ habitats as follows:

♦ Within all Sierra Nevada and mountain yellow-legged frog habitat April 15 or later

(dependent on sufficient snow to buffer vegetative habitat).

♦ Bald Eagle nesting habitat – September 1 to December 31

♦ California spotted owl/great gray owl nesting habitat – August 16 to April 30 

♦ Northern goshawk nesting – September 16 to February 14 

♦ Pacific marten denning habitat– August 1 to April 30

• Public OSV use would not be designated within 150 feet of waterways that support Lahontan 

cutthroat trout.

• Public OSV use would not be designated within 300 feet of lakes and 150 feet of rivers and 

streams.

• Both Class 1 and 2 OSVs are allowed on all designated OSV trails and areas. Class of vehicle 

definitions can be found on page 2.

• Approximately 217 miles of designated OSV trails are available for grooming. Approximately 38 

miles of marked, ungroomed trails are located within areas designated for cross-country OSV use. 

Approximately 25 miles of designated OSV trails are not available for grooming (table 9, figure 4 

in the map package).

• Implement forestwide snow depth requirements for public OSV use by:

a. Allowing public, cross-country OSV use in designated OSV use areas when there are 18 

or more inches of snow or ice covering the landscape, to prevent impacts to surface and 

subsurface resources including, but not limited to, archaeological deposits, historic 

features, and historic properties. Public OSV use on designated trails would be allowed 

when there are 18 or more inches of snow covering the trail.

b. Groom designated OSV snow trails when there are 18 inches or more of snow.

• There would be 3 designated OSV crossings of the PCT (table 10, figure 4 in the map package). 

In all cases, OSVs crossing the PCT would do so at 90 degrees to minimize the time and distance 

needed to cross the Trail. The 20 designated OSV crossings of the PCT would be as follows:

 Two designated crossings would utilize roads identified on the Tahoe National 

Forest’s Motor Vehicle Use Map and would be the width of the road (approximately 

14 feet). 

 One proposed OSV crossing of the PCT would range in width up to 0.13 miles. This

crossing is located in areas where OSV use is designated on either side of the PCT. 

OSV users would need a way to get across the Trail as OSV use along the PCT is 

prohibited by the National System Trails System Act, P.L 90-543, Section 7(c). This 
Draft Environmental Impact Statement – Volume I

Chapter 2. Alternatives

Tahoe National Forest

31

proposed OSV crossing is wider than the width of a road because they are located in 

areas where snow conditions are highly variable during the course of a winter, for 

example areas prone to wind loading of snow and formation of cornices. This wider

crossing give OSV users options to select a safe crossing of the Trail under 

constantly changing, variable snow loading conditions. 

Alternative 3 is summarized in table 8, table 9, and table 10 and displayed in figure 4 located in the 

map package.

Table 8. OSV use designations - alternative 3

Areas Considered for OSV Use 

Designation

Area size

(Total Acres)

OSV Designated Use

(Acres)

Barker 9,847 0

Black Buttes 41,252 29,589

Bowman 19,604 11,697

Donner Summit 11,634 1,765

Foresthill East 90,992 49,523*

Foresthill North 36,151 14,123

Foresthill West 32,957 0

Lafayette 46,807 301

Reservoirs 40,883 15,707

Sierraville East 75,557 32,460

Sierraville North 17,564 95

Sierraville West 96,311 77,290

South of 20 17,346 0

Summit West 15,560 0

Truckee 34,446 15,200

Yuba NE 83,273 27,679

Yuba NW 43,255 0

Yuba South 20,657 543

Yuba West 40,708 0

* Public OSV use is allowed between January 1 and September 14 for 1,408 acres.
Over-snow Vehicle Use Designation 

Tahoe National Forest

32

Table 9. OSV Trails – alternative 3

Designated OSV Trails Available for Grooming Trail Length

(Miles) OSV use Area

American Hill Trail 9.51 Foresthill East

Bald Ridge Loop Trail 14.40 Sierraville West

Bowman Trail 13.60 Bowman

Duncan “Y” Trail 5.14 Foresthill East

Fifty-Four Road Trail 12.54 Sierraville West

Yuba NE

Ford Point Trail 1.68 Foresthill East

Foresthill Divide Trail 14.21 Foresthill East

Haskell Peak Trail 15.55 Yuba NE

Howard Trail 5.40 Yuba NE

Humbug Tie Trail 0.82 Foresthill East

Humbug Trail 4.66 Foresthill East

Independence Lake Loop Trail 1.98 Sierraville West

Truckee 

Jackson Meadow Little Truckee Trail 14.61 Sierraville West

Lower Ford Point Trail 1.30 Foresthill East

Meadow Lake Loop Trail 6.18 Sierraville West

Mosquito Ridge Trail 6.78 Foresthill East

Pass Creek Loop Trail 7.58 Sierraville West

Prosser Creek CNNTR Trail 13.35 Sierraville West

Prosser Hill Winter Trail 1.05 Sierraville West

Rattlesnake Trail 10.10 Black Buttes

Ridge Loop Trail 6.05 Sierraville West

Rim Loop Trail 2.84 Sierraville West

Robinson Flat Trail 1.27 Foresthill East

Sawtooth Trail 1.21 Truckee

Soda Springs Trail 6.36 Foresthill East

Sterling Trail 2.30 Black Buttes

Tadpole Trail 3.01 Foresthill East

Treasure Mtn Loop Trail 16.17 Sierraville West

Yuba Webber Trail 17.00 Sierraville West

Yuba NE

Total 216.65

Marked, Ungroomed Trails for OSV Use

Gold Valley Trail 10.98 Yuba NE

Mosquito Ridge Trail 18.31 Foresthill East

Sawtooth Trail 9.02 Truckee

Total 38.31
Draft Environmental Impact Statement – Volume I

Chapter 2. Alternatives

Tahoe National Forest

33

Designated OSV trails Not available for grooming Trail Length

(Miles) OSV use Area

0787-004-05 (In the Boca Hill/Prosser Ranch Area) 0.51 Reservoirs

0787-004-10 (In the Boca Hill/Prosser Ranch Area) 0.12 Reservoirs

0787-004-15 (In the Boca Hill/Prosser Ranch Area) 0.21 Reservoirs

0787-010 (In the Boca Hill/Prosser Ranch Area) 2.00 Reservoirs

0787-010-20 (In the Boca Hill/Prosser Ranch Area) 0.69 Reservoirs

0890-010-10 (In the Boca Hill/Prosser Ranch Area) 1.11 Reservoirs

0890-014 (In the Boca Hill/Prosser Ranch Area) 0.58 Reservoirs

Boca 2.59 Reservoirs

Boca Boat Ramp 0.50 Reservoirs

Boca CCC 0.21 Reservoirs

Gold Valley Marked Snowmobile Trail 1.66 Yuba NE

Humps 2.68 Reservoirs

Humps Spur 0.74 Reservoirs

Martis Peak Trail 1.59 Truckee

Mosquito Ridge 4.47 Foresthill East

Old Reno Spur 3.68 Reservoirs

South Powerline Road 0.76 Reservoirs

U18171905 (In the Boca Hill/Prosser Ranch Area) 0.13 Reservoirs

U18171906 (In the Boca Hill/Prosser Ranch Area) 0.07 Reservoirs

U18172802 (In the Boca Hill/Prosser Ranch Area) 0.10 Reservoirs

Total 24.83

Table 10. Designated Pacific Crest Trail OSV crossings (displayed from south to north) – alternative 3

OSV/Pacific Crest National Scenic Trail Crossing Area

• 0086 (Meadow lake) Sierraville West

• 0070 (Pass Creek Loop) Sierraville West

• 0007 (Fibreboard) Sierraville West
Over-snow Vehicle Use Designation 

Tahoe National Forest

34

Alternative 4

This alternative addresses the quality recreational experience significant issue by emphasizing 

motorized use. The following summarizes how the Forest Service would manage public OSV use on 

the Tahoe National Forest under this alternative.

• Approximately 641,105 acres of National Forest System lands are designated for public OSV use

(table 11, figure 5 located in the map package). 

• Approximately 1,218 acres of National Forest System lands are designated for public crosscountry OSV use in deer holding areas from January 1 through September 14 (LRMP, page V30).

• Public OSV use would not be designated in a 1-acre area near Robinson Flat to protect historic 

structures.

• Implement forestwide snow depth requirements for public OSV use by:

a. Allowing public, cross-country OSV use in designated areas only when there are 12 or 

more inches of snow or ice covering the landscape, to prevent impacts to surface and 

subsurface resources including, but not limited to, archaeological deposits, historic features, 

and historic properties. On designated snow trails with underlying roads, a minimum of 6 

or more inches of snow covering is typically needed to avoid damage to the underlying 

road surface. 

b. Groom designated OSV snow trails when there are 12 inches or more of snow.

• Both Class 1 and 2 OSVs are allowed on all designated trails and areas. Class of vehicle 

definitions can be found on page 2.

• Approximately 260 miles of designated OSV trails are available for grooming. Approximately 22 

miles of marked, ungroomed trails are located within areas designated for cross-country OSV use.

Approximately 5 miles of designated OSV trails are not available for grooming (table 12, figure 5 

located in the map package).

• There would be 21 designated OSV crossings of the PCT (table 13, figure 5 located in the map 

package). In all cases, OSVs crossing the PCT would do so at 90 degrees to minimize the time 

and distance needed to cross the Trail.

 Thirteen crossings would utilize roads identified on the Tahoe National Forest’s Motor 

Vehicle Use Map and would be the width of the road (approximately 14 feet). 

 Eight proposed OSV crossings of the PCT would not utilize roads and would range in length 

from 0.13 miles to 1.31 miles.

Alternative 4 is summarized in table 11, table 12, and table 13, and figure 5 located in the map 

package.

Table 11. OSV use designations under alternative 4

Areas Considered for OSV Use 

Designation

Area Size

(Total Acres)

OSV Designated Use

(Acres)

Barker 9,847 9,783

Black Buttes 41,252 39,592

Bowman 19,604 18,033

Donner Summit 11,634 9,069
Draft Environmental Impact Statement – Volume I

Chapter 2. Alternatives

Tahoe National Forest

35

Areas Considered for OSV Use 

Designation

Area Size

(Total Acres)

OSV Designated Use

(Acres)

Foresthill East 90,992 89,198*

Foresthill North 36,151 34,026

Foresthill West 32,957 26,482

Lafayette 46,807 41,210

Reservoirs 40,883 40,883

Sierraville East 75,557 55,375

Sierraville North 17,564 17,564

Sierraville West 96,311 95,214

South of 20 17,346 10,078

Summit West 15,560 8,707

Truckee 34,446 21,393

Yuba NE 83,273 72,566

Yuba NW 43,255 37,717

Yuba South 20,657 14,140

Yuba West 40,708 76

* Public OSV use is allowed between January 1 and September 14 for 1,218 acres.

Table 12. OSV Trails – alternative 4

Designated OSV Trails Available for Grooming Trail Length

(Miles) Areas

American Hill Trail 9.51 Foresthill East

Bald Ridge Loop Trail 14.40 Sierraville West

Bowman Trail 13.60 Bowman

Black Buttes

Duncan “Y” Trail 5.14 Foresthill East

Fifty-Four Road Trail 12.54 Sierraville West

Yuba NE

Ford Point Trail 1.68 Foresthill East

Foresthill Divide Trail 14.21 Foresthill East

Haskell Peak Trail 15.55 Yuba NE

Howard Trail 5.40 Yuba NE

Humbug Tie Trail 0.82 Foresthill East

Humbug Trail 4.66 Foresthill East

Independence Lake Loop Trail 1.98 Sierraville West

Truckee

Jackson Meadow Little Truckee Trail 14.61 Sierraville West

Lower Ford Point Trail 1.30 Foresthill East

Meadow Lake Loop Trail 6.18 Sierraville West

Mosquito Ridge Trail 28.16 Foresthill East

Pass Creek Loop Trail 7.58 Sierraville West

Prosser Creek CNNTR Trail 13.35 Sierraville West

Prosser Hill Winter Trail 1.05 Sierraville West
Over-snow Vehicle Use Designation 

Tahoe National Forest

36

Designated OSV Trails Available for Grooming Trail Length

(Miles) Areas

Rattlesnake Trail 10.10 Black Buttes

Ridge Loop Trail 6.05 Sierraville West

Rim Loop Trail 2.84 Sierraville West

Robinson Flat Trail 1.27 Foresthill East

Sawtooth Trail 1.21 Truckee

Soda Springs Trail 6.36 Foresthill East

Sterling Trail 2.30 Black Buttes

Tadpole Trail 3.01 Foresthill East

Texas Hill/Mears 21.38 Foresthill North

Treasure Mtn Loop Trail 16.17 Sierraville West

Yuba Webber Trail 16.95 Sierraville West

Yuba NE

Total 259.36

Marked, Ungroomed Trails for OSV Use

Andesite West OSV Trail 2.88 Donner Summit

Summit West

Gold Valley Trail 11.46 Yube NE

Sawtooth Trail 7.69 Truckee

Total 22.03

Designated OSV trails Not Available for Grooming

Andesite West OSV Trail 0.59 Donner Summit

Gold Valley Trail 1.18 Yuba NE

Martis Peak Trail 1.81 Truckee

Sawtooth OSV Trail 1.33 Truckee

Total 4.91
Draft Environmental Impact Statement – Volume I

Chapter 2. Alternatives

Tahoe National Forest

37

Table 13. Designated Pacific Crest Trail OSV crossings (displayed from south to north) – alternative 4

OSV/Pacific Crest National Scenic Trail Crossing Area

16E75 (Rubicon Jeep) Barker

0003-004 (Niehaus) Barker

0003 (Barker Pass) Barker

T.18N., R.14E.,22 Sierraville West

0086 (Meadow Lake) Sierraville West

0070-040-20 (Moscove Spur) Sierraville West

0070-040 (Moscove) Sierraville West

0070-065 (Jackson Overlook) Sierraville West

0070 (Pass Creek Loop) Sierraville West

0007 (Fibreboard) Sierraville West

0093-002-03 (Monarch Spur) Yuba NE

T.20N., R.12E.,08 Yuba NE

T.20N., R.12E.,05 T.21N., R.12E.,32 Yuba NE

T.21N., R.12E.,29, 30 Yuba NE

T.21N., R.12E.,19, 30 Yuba NE

12E66 (Lots A Lakes OHV) Yuba NE

T.21N., R.11E.,13 T.21N., R.12E.,18, 19 Yuba NE

11E67 (Gold Valley OHV Trail) Yuba NE

T.21N., R.11E.,02 Yuba NE

11E68 (Lavezzola Creek OHV Trail) Yuba NE

2308-001 (Cowell Mine Rd.) Yuba NE
Over-snow Vehicle Use Designation 

Tahoe National Forest

38

Alternative 5

Alternative 5 emphasizes protections for wildlife and natural resources as well as quality recreational 

experiences for non-motorized recreation. The following summarizes how the Forest Service would 

manage public OSV use on the Tahoe National Forest under this alternative.

The following summarizes how the Forest Service would manage public OSV use on the Tahoe 

National Forest under this alternative:

• Approximately 300,146 acres of National Forest System lands are designated for public crosscountry OSV use (table 14, figure 6 in the map package).

• OSV use would be limited to designated OSV trails within 1 mile of existing OSV trailheads.

• Public cross-country OSV use would not be designated within a 1-acre area near Robinson Flat to 

protect historic structures.

• Individual parcels of National Forest System lands currently under long-term special use permits 

for Royal Gorge Cross Country Ski Area, Tahoe Donner Cross Country Ski Area, Boreal Ski 

Area, Donner Ski Ranch Ski Area, Sugar Bowl Ski Area, Alpine Meadows Ski Area and Squaw 

Valley Ski Area would not be designated for public OSV use.

• Implement forestwide snow depth requirements for public OSV use by:

a. Allowing public, cross-country OSV use in designated OSV use areas when there are 24 or 

more inches of snow or ice covering the landscape, to prevent impacts to surface and 

subsurface resources including, but not limited to, subnivean habitat, archaeological 

deposits, historic features, and historic properties. Public OSV use on designated trails 

would be allowed when there are 24 or more inches of snow covering the trail. All 

designated trails for public OSV use (including those identified for OSV grooming) would 

overlay an existing paved, gravel, or native surface travel route.

b. Groom designated OSV snow trails when there are 12 inches or more of snow.

• Class 1 OSVs are allowed on all designated OSV trails and areas. Class 2 OSVs are only allowed 

on designated OSV trails available for grooming. Class of vehicle definitions can be found on 

page 2.

• Approximately 215 miles of designated OSV trails are available for grooming. Groomed OSV 

trails would be the same as alternative 1, plus changing Howard’s Loop to an out and back ride 

by removing the section of trail that is not on an underlying roadbed from the trail system. 

Approximately 25 miles of marked, ungroomed trails are located within areas designated for 

cross-country OSV use. Approximately 17 miles of designated OSV trails are not available for 

grooming (table 15, figure 6 in the map package)

• OSV use would not be designated in areas within the Forest Service Scenery Management 

System definition of Foreground for the Pacific Crest Trail. This area would be up to one-half 

mile in the visible lands on each side of the Pacific Crest National Scenic Trail or smaller as the 

visible landscape along the Trail will be less than one-half mile on each side of the trail due to 

topography. Users could cross this non-motorized corridor on designated OSV trails. 

• Ten designated crossings would utilize roads identified on the Tahoe National Forest’s Motor 

Vehicle Use Map and would be the width of the road (approximately 14 feet). In one instance, 

the current alignment of the PCT overlays the Pass Creek Loop OSV Trail on Forest Service 

Road 70 for approximately 700 feet.
Draft Environmental Impact Statement – Volume I

Chapter 2. Alternatives

Tahoe National Forest

39

Alternative 5 is summarized in table 14, table 15, and table 16, and displayed in figure 6 located in 

the map package.

Table 14. OSV use designations for alternative 5

Areas Considered for OSV Use 

Designation

Area size

(Total Acres)

OSV Designated Use

(Acres)

Barker 9,847 7,111

Black Buttes 41,252 15,709

Bowman 19,604 10,147

Donner Summit 11,634 724

Foresthill East 90,992 39,783

Foresthill North 36,151 16,148

Foresthill West 32,957 0

Lafayette 46,807 13,593

North Fork Wild/Scenic River 31,146 0

Reservoirs 40,883 34,968

Sierraville East 75,557 28,788

Sierraville North 17,564 4,111

Sierraville West 96,311 74,596

South of 20 17,346 4,246

Summit West 15,560 0

Truckee 34,446 8,023

Yuba NE 83,273 24,480

Yuba NW 43,255 15,969

Yuba South 20,657 1,750

Yuba West 40,708 0

.
Over-snow Vehicle Use Designation 

Tahoe National Forest

40

Table 15. OSV Trails – alternative 5

Designated OSV Trails Available for Grooming Trail Length

(Miles) Areas

American Hill Trail 9.51 Foresthill East

Bald Ridge Loop Trail 14.40 Sierraville West

Bowman Trail 13.60 Bowman

Black Buttes

Duncan “Y” Trail 5.14 Foresthill East

Fifty-Four Road Trail 12.54 Sierraville West

Yuba NE

Ford Point Trail 1.68 Foresthill East

Foresthill Divide Trail 14.21 Foresthill East

Haskell Peak Trail 15.55 Yuba NE

Howard Trail 4.90 Yuba NE

Humbug Tie Trail 0.82 Foresthill East

Humbug Trail 4.66 Foresthill East

Independence Lake Loop Trail 1.98 Sierraville West

Truckee 

Jackson Meadow Little Truckee Trail 14.61 Sierraville West

Lower Ford Point Trail 1.30 Foresthill East

Meadow Lake Loop Trail 6.18 Sierraville West

Mosquito Ridge Trail 6.78 Foresthill East

Pass Creek Loop Trail 7.58 Sierraville West

Prosser Creek CNNTR Trail 13.35 Sierraville West

Prosser Hill Winter Trail 1.05 Sierraville West

Rattlesnake Trail 10.10 Black Buttes

Ridge Loop Trail 6.05 Sierraville West

Rim Loop Trail 2.84 Sierraville West

Robinson Flat Trail 1.27 Foresthill East

Soda Springs Trail 6.36 Foresthill East

Sterling Trail 2.30 Black Buttes

Tadpole Trail 3.01 Foresthill East

Treasure Mtn Loop Trail 16.17 Sierraville West

Yuba Webber Trail 17.00 Sierraville West

Yuba NE

Total 215.16

Marked, Ungroomed Trails for OSV Use

Gold Valley Trail 5.28 Yuba NE

Martis Peak Trail 0 .06 Truckee

Mosquito Ridge Trail 19.50 Foresthill East

White Rock Lake 0.21 Sierraville West

Total 25.05
Draft Environmental Impact Statement – Volume I

Chapter 2. Alternatives

Tahoe National Forest

41

Designated OSV trails not Available for Grooming Trail Length

(Miles) OSV use Area

Barker Pass 1.51 Barker

Cowell Mine Rd 1.93 Yuba NE

Gold Valley Marked Snowmobile Trail 2.12 Yuba NE

Martis Peak Trail 1.53 Truckee

Moscove 2.46 Sierraville West

Mosquito Ridge Trail 1.87 Foresthill East

Niehaus 0.86 Barker

Niehaus SP 0.45 Barker

North Miller OHV 0.20 Barker

Rubicon Jeep 1.66 Barker

Sawtooth OSV Trail 1.41 Truckee

Sierra Buttes OSV 0.95 Yuba NE

White Rock Lake 0.53 Sierraville West

Total 17.48

Table 16. Designated Pacific Crest Trail OSV crossings (displayed from south to north) – alternative 5

OSV/Pacific Crest National Scenic Trail Crossing Area

• 16E75 (Rubicon Jeep) Barker

• 0003-004 (Niehaus) Barker

• 0003 (Barker Pass) Barker

• 0086-070 (White Rock Lake) Sierraville West

• 0086 (Meadow Lake) Sierraville West

• 0070-040 (Moscove) Sierraville West

• 0070 (Pass Creek Loop) Sierraville West

• 0007 (Fibreboard) Sierraville West

• 12E07 (Sierra Buttes OHV) Yuba NE

• 2308-001 (Cowell Mine Rd.) Yuba NE
Over-snow Vehicle Use Designation 

Tahoe National Forest

42

Comparison of Alternatives

Table 17. Comparison of areas to be designated for OSV use, by alternative (acres)

Areas Considered for Designated OSV Use Area size

(Total Acres) Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Barker 9,847 9,783 9,783 0 9,783 7,111

Black Buttes 41,252 39,592 37,816 29,589 39,592 15,709

Bowman 19,604 18,033 10,966 11,697 18,033 10,147

Donner Summit 11,634 9,052 8,034 1,765 9,069 724

Foresthill East 90,992* 90,391* 54,585 49,523* 89,198* 39,783

Foresthill North 36,151 34,026 22,987 14,123 34,026 16,148

Foresthill West 32,957 26,482 0 0 26,482 0

Lafayette 46,807 41,209 14,183 301 41,210 13,593

Reservoirs 40,883 40,883 36,998 15,707 40,883 34,968

Sierraville East 75,557 55,375 29,004 32,460 55,375 28,788

Sierraville North 17,564 17,564 4,111 95 17,564 4,111

Sierraville West 96,311 95,214 93,050 77,290 95,214 74,596

South of 20 17,346 10,078 4,246 0 10,078 4,246

Summit West 15,560 4,466 0 0 8,707 0

Truckee 34,446 21,356 9,259 15,200 21,393 8,023

Yuba NE 83,273 72,566 54,588 27,679 72,566 24,480

Yuba NW 43,255 37,717 15,268 0 37,717 15,969

Yuba South 20,657 14,139 1,750 543 14,139 1,750

Yuba West 40,708 76 267 0 76 0

Total** 774,804 638,002 406,895 275,972 641,105 300,146

*Public OSV use is allowed between January 1 and September 14 for 1,218 acres in alternatives 1, and 4, alternative 3 is 1,408 acres.

**Totals do not include the OSV Areas of Granite Chief Wilderness and North Fork American Wild and Scenic River

All area size estimates are approximate and are rounded to the nearest whole number.
Draft Environmental Impact Statement – Volume I

Chapter 2. Alternatives

Tahoe National Forest

43

Table 18. Comparison of trails for OSV use, by alternative (miles)

Trail Areas Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5 

Designated OSV Trails Available for Grooming

American Hill Trail Foresthill East 9.51 9.51 9.51 9.51 9.51

Bald Ridge Loop Trail Sierraville West 14.40 14.40 14.40 14.40 14.40

Bowman Trail Bowman 13.60 13.60 13.60 13.60 13.60

Duncan “Y” Trail Foresthill East 5.14 5.14 5.14 5.14 5.14

Fifty-Four Road Trail Sierraville West

Yuba NE

12.54 12.54 12.54 12.54 12.54

Ford Point Trail Foresthill East 1.68 1.68 1.68 1.68 1.68

Foresthill Divide Trail Foresthill East 14.21 14.21 14.21 14.21 14.21

Haskell Peak Trail Yuba NE 15.55 15.55 15.55 15.55 15.55

Howard Trail Yuba NE 5.40 5.40 5.40 5.40 4.90

Humbug Tie Trail Foresthill East 0.82 0.82 0.82 0.82 0.82

Humbug Trail Foresthill East 4.66 4.66 4.66 4.66 4.66

Independence Lake Loop Trail Sierraville West

Truckee 

1.98 1.98 1.98 1.98 1.98

Jackson Meadow Little Truckee Trail Sierraville West 14.61 14.61 14.61 14.61 14.61

Lower Ford Point Trail Foresthill East 1.30 1.30 1.30 1.30 1.30

Meadow Lake Loop Trail Sierraville West 6.18 6.18 6.18 6.18 6.18

Mosquito Ridge Trail Foresthill East 6.78 28.16 6.78 28.16 6.78

Pass Creek Loop Trail Sierraville West 7.58 7.58 7.58 7.58 7.58

Prosser Creek CNNTR Trail Sierraville West 13.35 13.35 13.35 13.35 13.35

Prosser Hill Winter Trail Sierraville West 1.05 1.05 1.05 1.05 1.05

Rattlesnake Trail Black Buttes 10.10 10.10 10.10 10.10 10.10

Ridge Loop Trail Sierraville West 6.05 6.05 6.05 6.05 6.05

Rim Loop Trail Sierraville West 2.84 2.84 2.84 2.84 2.84

Robinson Flat Trail Foresthill East 1.27 1.27 1.27 1.27 1.27

Sawtooth Trail Truckee 1.21 0 1.21 1.21 0

Soda Springs Trail Foresthill East 6.36 6.36 6.36 6.36 6.36
Over-snow Vehicle Use Designation 

Tahoe National Forest

44

Trail Areas Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5 

Sterling Trail Black Buttes 2.30 2.30 2.30 2.30 2.30

Tadpole Trail Foresthill East 3.01 3.01 3.01 3.01 3.01

Texas Hill/Mears Foresthill North 0 0 0 21.38 0

Treasure Mtn Loop Trail Sierraville West 16.17 16.17 16.17 16.17 16.17

Yuba Webber Trail Sierraville West

Yuba NE

17.00 17.00 17.00 16.95 17.00

Total 216.65 237.04 216.65 259.36 214.94

Marked, Ungroomed Trails for OSV Use

Andesite West OSV Trail Donner Summit

Summit West 

2.47 1.68 0 2.88 0

Gold Valley Trail Yuba NE 11.46 12.64 10.98 11.46 5.28

Martis Peak Trail Truckee 0 0 0 0 0.06

Mosquito Ridge Trail Foresthill East 21.11 0 18.31 0 19.50

Sawtooth Trail Truckee 6.22 0 9.02 7.69 0

White Rock Lake 0 0 0 0 0.21

Total 41.25 14.32 38.31 22.03 25.05

Designated OSV Trails Not Available for Grooming

Andesite West OSV Trail Donner Summit

Summit West

1.00 1.79 0 0.59 0

Barker Pass Barker 0 0 0 0 1.51

Bear Valley Sierraville East 0 6.52 0 0 0

Boca Reservoirs 0 0 2.59 0 0

Boca Boat Ramp Reservoirs 0 0 0.50 0 0

Boca CCC Reservoirs 0 0 0.21 0 0

CAL IDA Scales Yuba NW 0 14.86 0 0 0

Carmen Valley Sierraville North 0 8.06 0 0 0

Carmen Valley Spur Sierraville North 0 1.7 0 0 0

Cowell Mine Rd Yuba NE 0 0 0 0 1.93

Eureka Yuba NW 0 6.49 0 0 0

Frosty East Sierraville North 0 5.01 0 0 0
Draft Environmental Impact Statement – Volume I

Chapter 2. Alternatives

Tahoe National Forest

45

Trail Areas Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5 

Gold Valley Trail Sierraville North 1.18 0 1.66 1.18 2.12

Humps Reservoirs 0 0 2.68 0 0

Humps Spur Reservoirs 0 0 0.74 0 0

Martis Peak Trail Truckee 1.81 1.81 1.59 1.81 1.53

Moscove Sierraville West 0 0 0 0 2.46

Mosquito Ridge Foresthill East

Foresthill West

0.27 18.72 4.47 0 1.87

Niehaus Barker 0 0 0 0 0.86

Niehaus SP Barker 0 0 0 0 0.45

North Miller OHV Barker 0 0 0 0 0.20

North Tie Sierraville North 0 0.05 0 0 0

Rubicon Jeep Barker 0 0 0 0 1.66

Sawtooth OSV Trail Truckee 2.81 1.40 0 1.33 1.41

Sierra Buttes OSV Yuba NE 0 0 0 0 0.95

Texas Hill/Mears Foresthill North 0 3.83 0 0 0

Un-named (Boy Scout Camp to Yuba River) Yuba NE 0 0.56 0 0 0

Old Reno Spur Reservoirs 0 0 3.68 0 0

South Powerline Road Reservoirs 0 0 0.76 0 0

White Rock Lake Sierraville West 0 0 0 0 0.53

0787-004-05 (In the Boca Hill/Prosser Ranch Area) Reservoirs 0 0 0.51 0 0

0787-004-10 (In the Boca Hill/Prosser Ranch Area) Reservoirs 0 0 0.12 0 0

0787-004-15 (In the Boca Hill/Prosser Ranch Area) Reservoirs 0 0 0.21 0 0

0787-010 (In the Boca Hill/Prosser Ranch Area) Reservoirs 0 0 2.00 0 0

0787-010-20 (In the Boca Hill/Prosser Ranch Area) Reservoirs 0 0 0.69 0 0

0890-010-10 (In the Boca Hill/Prosser Ranch Area) Reservoirs 0 0 1.11 0 0

0890-014 (In the Boca Hill/Prosser Ranch Area) Reservoirs 0 0 0.58 0 0

U18171905 (In the Boca Hill/Prosser Ranch Area) Reservoirs 0 0 0.13 0 0

U18171906 (In the Boca Hill/Prosser Ranch Area) Reservoirs 0 0 0.07 0 0

U18172802 (In the Boca Hill/Prosser Ranch Area) Reservoirs 0 0 0.10 0 0
Over-snow Vehicle Use Designation 

Tahoe National Forest

46

Trail Areas Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5 

Total 7.06 70.24 24.83 4.91 17.48
Draft Environmental Impact Statement – Volume I

Chapter 2. Alternatives

Tahoe National Forest

47

Suggested Alternatives or Alternative Components Considered 

The Responsible Official carefully considered each of the public suggestions below to determine 

whether the suggestion should be carried forward into detailed analysis in the EIS or dismissed from 

further consideration. Suggestions carried forward into detailed analysis could become a new 

alternative or part of a revision to the proposed action.

For an alternative to be analyzed in detail in the EIS, it must meet the purpose and need for action, 

must address one or more significant issues, and address unresolved conflicts related to the proposed 

action. Alternatives should be considered, even if outside the jurisdiction of the agency (40 CFR 

1502.14(c)). Reasonable alternatives include those that are practical or feasible from a technical and 

economic standpoint and use common sense. Alternatives not considered in detail in the EIS may 

include, but are not limited to, those that fail to meet the purpose and need, are technologically 

infeasible or illegal, or would result in unreasonable environmental harm.

The suggested alternatives are summarized below.

Ensure OSV use designations avoid municipal watersheds.

There are no Forest Service designated municipal watersheds in the project area; however, the 

majority of water that flows off of National Forest System lands contribute to drinking water supplies 

for the States of California and Nevada.

Modify the minimum snow depth for cross-country OSV use to more or less than 

12 inches. Also, lower the 6-inch snow depth to 2 inches or a range of 2-6 inches to 

accommodate access to areas with greater snow depths.

We heard a range of snow depth suggestions from commenters during the scoping process. Snow 

depth varies by the alternatives analyzed in detail in the EIS.

Ensure monitoring and enforcement are part of the proposal.

Monitoring and enforcement are critical to the success of implementation. A monitoring discussion 

can be found on page 20 of this DEIS.

Include, in any action, a prohibition of recreational OSV travel on or across open or 

flowing water.

This planning effort addresses OSV use on National Forest System lands. Therefore, OSV use on 

open water, such as lakes and ponds is not addressed.

Consider a suggestion for an alternative to the proposed action with an emphasis on 

providing additional opportunities for non-motorized users.

Alternatives 3 and 5 have been developed to address this suggestion and are included for detailed 

analysis in the EIS. However, not all aspects of the suggested alternative 3 are within the scope of the 

analysis, as described below, and these specific components have been dismissed from further 

detailed analysis: 

• Designation of non-motorized trailheads to access non-motorized areas.

♦ The designation of non-motorized trailheads is outside the scope of the purpose and need 

for action which is to provide a manageable, designated OSV system of areas and trails for 
Over-snow Vehicle Use Designation 

Tahoe National Forest

48

public use within the Tahoe National Forest, that is consistent with and achieves the 

purposes of the Forest Service Travel Management Rule at 36 CFR Part 212, subpart C. 

Therefore this feature would not be included in Alternative 3 to be analyzed in detail.

• Monitoring of ambient air quality and noise near trails, in trailheads, and in OSV areas with 

heavy over-snow vehicle traffic.

♦ The monitoring of ambient air quality and noise is outside the scope of the purpose and 

need for action, which is to provide a manageable, designated OSV system of areas and 

trails for public use within the Tahoe National Forest that is consistent with and achieves 

the purposes of the Forest Service Travel Management Rule at 36 CFR Part 212, subpart C. 

The Forest Service has no regulatory jurisdiction over air quality or noise. There are no 

standards which would allow the Forest Service to identify or enforce prohibitions against 

unacceptable noise or air quality levels. These levels are set by state law. The OSV Program 

Monitoring Checklist for the California Department of Parks and Recreation, OHMVR 

Division, and U.S. Forest Service does not include ambient air quality monitoring 

(California OSV Program EIR, Program Years 2010-2020, appendix C). Therefore this 

feature will not be included in Alternative 3 to be analyzed in detail. The EIS, however, will 

examine effects on air quality and noise from the proposed action and alternatives to the 

proposed action, including the indirect effects of changes in air quality and noise levels on 

forest resources.

• Transition to cleaner and quieter OSVs through encouragement of best available technology 

(BAT) forestwide to reduce air and noise pollution. Exception is in the “Managed Shared Use”

area where air quality and noise monitoring every five years will determine whether mandatory 

BAT would be needed.

♦ The imposition of best available technology requirements is outside the scope of the 

purpose and need for action, which is to provide a manageable, designated OSV system of 

areas and trails for public use within the Tahoe National Forest that is consistent with and 

achieves the purposes of the Forest Service Travel Management Rule at 36 CFR Part 212, 

subpart C. The regulation of best available technology, whether only encouraged or 

mandated, is outside the scope of this analysis. The Forest Service has no regulatory 

jurisdiction over air quality or noise and there are no Forest Service directives requiring the 

establishment of standards. Therefore this feature will not be included in alternative 3 to be 

analyzed in detail.

• Nordic trail grooming.

♦ Grooming of trails for non-motorized use would not address the purpose and need for 

action which is to provide a manageable, designated OSV system of areas and trails for 

public use within the Tahoe National Forest, that is consistent with and achieves the 

purposes of the Forest Service Travel Management Rule at 36 CFR Part 212, subpart C. 

The purpose and need for action calls for identifying those designated National Forest 

System OSV trails where grooming for OSV use could occur. Therefore, this feature would 

not be included in alternative 3 to be analyzed in detail.

• Granting of access rights to private lands.

♦ Over-snow vehicle use that is specifically authorized under a written authorization issued 

under Federal law or regulations is exempt from subpart C designations (36 CFR Part 

261.14(e)). The granting or maintenance of such access is outside the scope of the purpose 

and need for action, which is to provide a designated system of areas and trails for 

motorized over-snow vehicle use within the Tahoe National Forest that is consistent with 
Draft Environmental Impact Statement – Volume I

Chapter 2. Alternatives

Tahoe National Forest

49

and achieves the purposes of the Forest Service Travel Management Rule at 36 CFR Part 

212, subpart C. Therefore this feature will not be included in alternative 3 to be analyzed in 

detail. Under the scope of this project, the Forest Service would only designate routes under 

subpart C of the Travel Management Rule that are available for public use. Therefore, 

designating routes specifically for access to private lands, and not for public use, would not 

fall within the scope of this analysis or subpart C of the Travel Management Rule. 

• Tahoe National Forest should designate appropriate areas for snow play. Designation of snow 

play areas allows for concentration of use in areas that are appropriate for snow play and that 

have adequate parking. Such areas and their primary access routes should be closed to OSV

traffic for safety and other reasons.

♦ The designation of snow play areas is outside the scope of the purpose and need for action, 

which is to provide a designated system of areas and trails for motorized over-snow vehicle 

use within the Tahoe National Forest that is consistent with and achieves the purposes of 

the Forest Service Travel Management Rule at 36 CFR Part 212, subpart C. Therefore, this 

feature will not be included in alternative 3 to be analyzed in detail. 

Designate OSV crossings of the Pacific Crest Trail, using the same crossings as 

designated by wheeled motorized vehicles shown on the subpart B Motor Vehicle Use 

Map.

The Responsible Official has included this concept in all alternatives except alternative 1 (no action).

Segregate motorized and non-motorized user groups by designating separate 

trailheads, separate trails and/or separate areas. Designate specific areas as 

snowplay areas.

Motorized and non-motorized recreational experiences are important concerns to be considered for 

this analysis (see Significant Issues). However, the development of new facilities such as new 

trailheads, new trails, or new snowplay areas are outside the scope of this project. This analysis is 

focused on the designation of OSV use and grooming of OSV trails. For this reason, this suggestion 

has been dismissed from further detailed analysis. However, we agree that facility improvements or 

changes may be valuable and/or necessary in the future.

Ensure OSV use is restricted in riparian areas, in streams and on frozen lakes

We considered this suggestion and have developed alternatives that does not designate OSV use when 

there is not adequate snow to prevent resource damage. This planning project only addresses OSV use 

on National Forest System lands. Water bodies (lakes), frozen or not, are not within the scope of this 

analysis.

Consider an alternative with an emphasis on providing additional opportunities for 

motorized users 

Alternative 4, which emphasizes providing additional opportunities for winter motorized recreational 

use, is included for detailed analysis in the EIS. However, not all aspects of this suggested alternative 

are within the scope of the analysis, and these elements have been dismissed from further detailed 

analysis, as described below: 

This suggested alternative recommends designating several OSV trails that are ungroomed but 

located within areas where cross-country OSV use would be designated under the proposed action. 
Over-snow Vehicle Use Designation 

Tahoe National Forest

50

Since these trails would be unmarked, ungroomed, and located in areas where cross-country OSV use 

would be designated, the Agency sees no need to designate them in the proposed action. 

• This suggested alternative recommends designating several OSV trails that are ungroomed but 

located within areas where cross-country OSV use would be allowed by the proposed action. 

Where trails would be unmarked, ungroomed, and located in areas where cross-country OSV use 

would be allowed, the agency sees no need to designate them in the applicable lternatives.

♦ Many of these ungroomed trails pass through lands not under Forest Service jurisdiction. 

Establishment of Forest Service jurisdiction would be required for these trails to be 

designated for OSV use under subpart C.

• This suggested alternative recommends a sound standard for OSVs. The Forest Service has no 

regulatory jurisdiction over noise. These levels are set by state law. The OSV Program 

Monitoring Checklist for the California Department of Parks and Recreation, OHMVR Division, 

and Forest Service does not include ambient noise monitoring. Therefore this feature will not be 

included. The DEIS, however, will examine effects on noise from the proposed action and 

alternatives to the proposed action, including the indirect effects of changes in noise levels on 

forest resources.

• This suggested alternative recommends adding narrow groomed trails (using equipment with 

8 feet or narrower width) to allow for utilizing more OHV trails where a larger groomer cannot 

fit. As part of the OSV trail grooming program, the Forest Service follows California State Parks 

Off-Highway Motor Vehicle (OHMVR) Division grooming standards, including state trail-width 

standards and existing equipment abilities. Standards state, “Trails should be groomed at a 

minimum of 10 feet wide, with wider trails when necessary due to traffic and other conditions. 

Where the terrain allows, main ingress and egress trails that connect to the trailhead should be 

groomed to 14 feet wide or greater to facilitate the added traffic.” Deviation of groomed trail 

width down to 8 feet wide is not feasible at this time, given the type and size of grooming 

equipment currently in use and will not be analyzed in this document.

• This suggested alternative recommends a review and update of parking and staging facilities. The 

purpose and need for action is to provide a manageable, designated OSV system of areas and 

trails that is consistent with and achieves the purposes of the Forest Service Travel Management 

Rule at 36 CFR part 212. The creation or addition of new parking areas at trailheads does not fall 

within the scope of these designations, and therefore, this recommendation will not be included.

• This suggested alternative recommends that designating non-motorized companion trails along 

motorized routes or designating/grooming non-motorized only trails to Wilderness or nonmotorized land classification to reduce conflict of uses. The creation of non-motorized 

companion trails that do not currently exist along designated motorized routes and the 

designation/grooming of non-motorized only trails to Wilderness or non-motorized land 

classification would not address the purpose and need and are beyond the scope of this project.

• This suggested alternative recommends that the Forest Service consider a special user-fee 

pass/permit system “Fee- Demo” that is specific to an area, Forest, or Ranger District, specifically 

on-site self-service stations where a pass can be purchased to support on-the-ground services at 

said unit. Fees would be collected from both motorized and non-motorized users benefitted by 

any necessary management activities. Imposing user fees at additional winter recreation areas 

would not address the purpose and need for action and this action is outside the scope of this 

analysis.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

51

Chapter 3. Affected Environment and Environmental 

Consequences

Introduction

This chapter presents the relevant resource components of the existing environment-the baseline 

environment. It describes the resources of the area that would be affected by the alternatives. This 

chapter also discloses the environmental effects of implementing the alternatives. These form the 

scientific and analytical basis for comparing the alternatives described in chapter 2.

The effects of the modified proposed action were aggregated rather than describing the site-specific 

effect at each road or trail, unless necessary for a particular sensitive resource or concern area. For 

instance, specialists’ reports describe the overall effects of designating places people could ride OSVs 

instead of listing every route and predicting the effects at a particular site.

OSV Use Assumptions

Assumptions regarding areas of high, moderate, low and potential public OSV use were identified on 

an assumptions map (Appendix H). This OSV use assumptions map was utilized by all resource 

specialists when conducting their analyses. In addition to observed use, the following criteria were 

used to spatially delineate areas of the forest with different levels of potential public OSV use:

High use: Areas within 0.5 mile of staging areas and of groomed trails; meadows within 

0.5 mile of a groomed trail.

Moderate use: Areas within 0.5 mile of marked (not groomed) trails; areas between 0.5 mile 

and 1.5 miles of groomed routes; meadows 10 acres or greater in size or 0.5 to 1.5 miles from 

OSV trails.

Low or no use: Areas where OSV use is prohibited or restricted under current management; 

areas below 5,000 feet elevation; California wildlife habitat relationships (CWHR) Vegetation 

2D, 3D, 4D, 4M; vegetation types 5 and 6 with a slope greater than 20 percent; meadows 30 

acres or greater, 1.5 miles or greater from OSV trail; areas more than 1.5 miles from groomed 

OSV trail; areas more than 0.5 mile from marked (not groomed) OSV trail.

Potential use: CWHR Vegetation Open Areas (annual grass, barren, lacustrine, mixed 

chaparral, montane chaparral, perennial grass, sagebrush, wet meadow, and urban)

Additional resource specific assumptions utilized during effects analysis are disclosed in the 

applicable sections of this chapter.

Past, Present, and Reasonably Foreseeable Actions

The interdisciplinary team considered the effects of past actions as part of the existing condition. The 

current conditions are the sum total of past actions. The Council on Environmental Quality recognizes 

“agencies can conduct an adequate cumulative effects analysis by focusing on current aggregate 

effects of past actions without delving into the historical details of individual past actions” (Council 

on Environmental Quality 2005). Innumerable actions over the last century and beyond have shaped 

the Tahoe National Forest’s current designated road system within the planning area. Attempting to 

isolate and catalog these individual actions and their effects would be nearly impossible. By looking 
Over-snow Vehicle Use Designation 

Tahoe National Forest

52

at current conditions, the effects of past human actions and natural events, regardless of which event 

contributed to those effects are captured. 

Courts have interpreted a “reasonably foreseeable future action” as one that has been proposed and is 

in the planning stages. To analyze the cumulative effects of present and reasonably foreseeable future 

actions, each resource specialist looked at the list of projects in Volume II of this DEIS, Appendix C. 

They identified the ones expected to cause effects to their resource, at the same time and in the same 

place as effects from the proposed action or alternatives. 

Recreation Resources

Relevant Laws, Regulations, and Policy

Regulatory Framework

National Forest Management Act

Specifically for off-highway vehicle management, the National Forest Management Act (NFMA) 

requires that this use be planned and implemented to protect land and other resources, promote public 

safety, and minimize conflicts with other uses of the National Forest System lands. NFMA also 

requires that a broad spectrum of forest and rangeland-related outdoor recreation opportunities be 

provided that respond to current and anticipated user demands. 

Sierra Nevada Forest Plan Amendment

The Sierra Nevada Forest Plan Amendment established standards and guidelines specific to wheeled 

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 OSVs would continue (forestwide standard and guideline 

number 69 (USDA Forest Service 2009)).

Land and Resource Management Plan

The 1990 Tahoe National Forest Land and Resource Management Plan provides forestwide and 

management area-specific goals and strategies, desired future conditions, land allocation, and 

standards and guidelines relevant to winter recreation as follows:

Management Goals and Strategies:

Recreation:

Provide a broad spectrum of dispersed and developed recreation opportunities in accordance with 

identified needs and demands.

Recreation management will be in concert and cooperation with appropriate City, County, State, and 

other Federal agencies.

Manage the North Fork American Wild River in accordance with Public Law 95-625, which 

documents the Congressional designation of the River. Implement the management and development 

plan, the Wild Trout Plan, and the habitat management plans for the North Fork.

Develop several National Recreation Trail proposals for consideration during the trail implementation 

planning process. Emphasize developing a variety of trails that would provide for a wide range of 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

53

recreation uses including hiking, equestrian, snowmobile, cross-country skiing, motorcycle, 

jeep/OHV, handicapped, and historical activities. Develop proposals for National Recreation Trail

designation that would include needed facilities such as new or augmented trailheads and additional 

trails to create loops for improved recreational experiences. Identify and evaluate opportunities for 

trailheads and trails with easy access from urban areas along main routes to the forest.

Recognize the value of semi-primitive motorized (SPM) and non-motorized (SPNM) areas in the 

forest because of their scarcity and the demand for the few acres remaining. Closely monitor the loss 

of inventoried SPNM and SPM land that is not allocated in the Tahoe National Forest Land and 

Resource Management Plan for these ROS classes. Where possible, avoid losing SPM and SPNM 

areas during the planning period by considering options that would not road the areas significantly.

Visual Management:

Maintain visual quality at the visual quality objective (VQO) level specified in each management 

area, as a minimum, but maintain higher visual quality wherever practical and compatible with other 

goals.

Wilderness

Manage the Granite Chief Wilderness area to preserve the wilderness character of its living and 

nonliving components and to provide for compatible human use and enjoyment.

Provide quality wilderness experiences for the public.

Pacific Crest National Scenic Trail

The Pacific Crest National Scenic Trail (PCNST) crosses the Tahoe National Forest. As required by 

public law 95-625, the Secretary of Agriculture was to prepare a comprehensive plan for the 

development, use, and protection of the PCNST. The Secretary assigned planning responsibilities to 

the Forest Service, which has overall responsibility for administration and coordination for the Trail. 

On April 15, 1982, Associate Chief Douglas Leisz signed the 'Notice of Decision and Finding of No 

Significant Impact--Comprehensive Management Plan for the Pacific Crest National Scenic Trail.' 

This plan states the following direction:

Viewing and understanding resource management are considered to be part of the normal 

character of the trail. The management of the various resources will give due consideration to 

the existence of the trail and trail users within the multiple-use concept. Prescription for 

management of the visual resources associated with the trail will be part of agency planning 

process.'

Recommended Wild and Scenic Rivers:

• Sagehen Creek

To the extent the Forest Service is authorized under law to control stream impoundments and 

diversions, the free-flowing characteristics of Sagehen Creek will not be modified.

Outstandingly remarkable values for Sagehen Creek shall be protected, and or enhanced, to the extent 

practicable.
Over-snow Vehicle Use Designation 

Tahoe National Forest

54

Control management and development of public lands on Sagehen Creek within a 1⁄2 mile corridor. 

Protect this corridor from modification to the degree that eligibility and classification would be 

affected based on the inventory classification.

• North Yuba River, Canyon Creek, and lower South Yuba River

To the extent the Forest Service and Bureau are authorized under law to control stream impoundments 

and diversions, the free-flowing characteristics of the North Yuba River, Canyon Creek, and lower 

South Yuba River cannot be modified

Outstandingly remarkable values for the North Yuba River, Canyon Creek, and lower South Yuba 

River shall be protected, and/or enhanced, to the extent practicable.

Control management and development of Public lands on the North Yuba River, Canyon Creek, and 

lower South Yuba River and its 1⁄2 mile corridor. Protect these corridors from modification to the 

degree that eligibility and classification would be affected based on the inventory classification.

Forestwide Desired Future Conditions

Management Standards and Guidelines

OSV Use

The Tahoe National Forest LRMP uses management area-specific standards and guidelines to 

establish OSV use designations across the Tahoe National Forest. Each of the Forest’s 109 

management areas has a standard and guideline that specifies if: (1) the management area is open to 

OSV travel (for example, the Lavezzola Management Area, LRMP, pg. V-95) or (2) closed to OSV 

travel (for example, the Coolbrith Management Area, LRMP, pg. V-85) or (3) OSVs are restricted to 

designated routes (for example, the Queens Management Area, LRMP, pg. V-339). Some of the 

Forest’s management areas have a standard and guideline that closes a portion of the management 

area to OSVs, sometimes during a particular season (for example, the Pendola Management Area, 

LRMP, pg. V-174). Appendix B displays the Tahoe National Forest LRMP OSV use standards and 

guidelines for each of the Forest Plan’s 109 management area.

Recreation Opportunity Spectrum

The Tahoe National Forest LRMP uses forestwide standards and guidelines to define the following 

Recreation Opportunity Spectrum classes: Primitive (P), Semi Primitive Non-Motorized (SPNM), 

Semi Primitive Motorized (SPM), Roaded Natural (RN), Rural (R), and Modern Urban (MU) 

(LRMP, Forestwide Standards and Guidelines #8 through #13, pp. V-20 through V-22). Descriptions 

of each ROS class from the Forest Plan are in the Existing Conditions section, below. Each of the 

Forest Plan’s 109 management areas is assigned an ROS class (TNF LRMP, pp. V-69 through V544).

Visual Quality Ojectives

The Tahoe National Forest LRMP uses standards and guidelines to establish visual quality objectives 

across the Forest. Each of the Forest Plan’s 109 management areas has a standard and guideline 

specifying visual quality objectives for the management area (TNF LRMP, pp. V-69 through V-544). 

Visual quality objective standards and guidelines define the following visual quality objectives 

(VQOs): Preservation (P), Retention (R), Partial Retention (PR), Modification (M), and Maximum 

Modification (MM) (LRMP, Forestwide Standards and Guidelines #16 through #20, pp. V-24 

through V-25). 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

55

Pacific Crest National Scenic Trail Management

The Tahoe National Forest LRMP provides the following direction for managing the Pacific Crest 

National Scenic Trail (PCT): The standards and guidelines for location, design, signing, user 

facilities, and management of the PCT will be in accordance with the criteria established in the PCT 

Comprehensive Plan, 1/18/82.

The 1982 Comprehensive Plan provides the following direction for winter use along the PCT:

Winter use (cross-country skiing and snowshoeing) should be accommodated where practical 

and feasible. Each agency should follow its own procedures for marking and signing the trail 

for winter use purposes. As a guideline, all trail markers should be at eye level 

(approximately 40” above average maximum snow depth). Sanitation facilities and snow 

removal for parking may be necessary. Any improvements, or alterations of the vegetation, 

should not detract from the quality of the recreation opportunities for other trail activities 

such as hiking and horseback riding.

Snowmobiling along the Trail is prohibited by the National Trails System Act, P.L. 90-543, 

Section 7(c). Winter sports plans for areas through which the trail passes should consider this 

prohibition in determining areas appropriate for snowmobile use. Winter sports brochures 

should indicate designated snowmobile crossings on the Pacific Crest Trail where it is signed 

and marked for winter use. If cross-country skiing and/or snowshoeing is planned for the 

trail, any motorized use of adjacent land should be zoned to mitigate the noise of conflict.

Special Area Designations

• North Fork American Wild River – congressional designation, Public Law 95-625

• Granite Chief Wilderness – congressional designation 

• Onion Creek Experimental Forest, designated by the Chief of the Forest Service on 

December 29, 1958, will continue to be managed for watershed research under an agreement 

with the Pacific Southwest Forest and Range Experiment Station

• Sagehen Experimtental Forest, designated by the Chief of the Forest Service on November 

28, 2005

• Pacific Crest National Scenic Trail (PCNST) – congressional designation

Federal Law

Laws, regulations and policies applicable to OSV use designations include the following:

• Wilderness Act of 1964, California Wilderness Act of 1984, and applicable Wilderness 

Implementation Plans

• Wild and Scenic Rivers Act of 1968 and applicable Wild and Scenic River Plans

• National Trails System Act of 1968 (P.L. 90-543) and the Pacific Crest National Scenic Trail 

Comprehensive Plan

• 2005 Travel Management Rule – Subpart C (36 CFR Parts 212 and 261) as amended in 2015 

- Use by Over-snow Vehicles (Travel Management Rule)
Over-snow Vehicle Use Designation 

Tahoe National Forest

56

Executive Orders

Executive Order 11644 of February 8, 1972, as amended by Executive Order 11989 of May 24, 1977, 

and by Executive Order 12608 of September 9, 1987, requires certain Federal agencies, including the 

Forest Service, to “ensure that the use of off-road vehicles on public lands [is] 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.”

Other Guidance or Recommendations

National Best Management Practices for Water Quality Management on National Forest System 

Lands - Rec - 7 Over Snow Vehicle Use. 

The California Off-Highway Motor Vehicle Recreation Division of the California Department of 

Parks and Recreation provides funding for operating, maintaining, and grooming of winter recreation 

trails and trailheads in mountainous regions throughout California. OSV trail grooming and ancillary 

activities, such as trailhead plowing and maintenance are described in detail in the OSV Program 

Draft and Final Environmental Impact Report (EIR), Program Years 2010−2020. The EIR includes 

annual monitoring and reporting requirements for Forest Service participation in the grooming 

program (California Department of Parks and Recreation 2010). 

Methodology 

This analysis used ArcMap and relevant GIS data layers from the Tahoe National Forest, wilderness 

areas, inventoried roadless areas, national trails, wild and scenic rivers, research natural areas, etc. 

The GIS layer of proposed OSV designations and groomed trails was used as an overlay with the 

recreation settings and opportunities, scenery, access and designated area layers listed above to 

determine any potential conflicts. 

Forest Plan direction was considered to ensure compliance with management direction. A review of 

existing law, regulation, and policy relevant to recreation settings and opportunities, access, scenery, 

and designated area resources within the project area was completed and referenced where 

appropriate.

The requirements of the Travel Management Rule, Subpart C, including the general criteria for 

designation of roads, trails and areas (36 CFR 212.55(a)):

• Natural and cultural resources

• Public safety

• Provision of recreational opportunities

• Access needs

• Conflicts among uses of National Forest System lands 

• Need for maintenance and administration of roads, trails and areas that would arise if uses under 

consideration are designated and availability of resources for that maintenance and 

administration. 

And the specific criteria to consider effects on the following with the objective of minimizing (36 

CFR 212.55 (b)): 

1. Damage to soil, watershed, vegetation, and other forest resources;
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

57

2. Harassment of wildlife and significant disruption of wildlife habitats;

3. Conflicts between motor vehicle use and existing or proposed recreational uses of 

National Forest System lands or neighboring Federal lands; and

4. Conflicts among different classes of motor vehicle uses of National Forest System lands 

or neighboring Federal lands. 

In addition:

5. Compatibility of motor vehicle use with existing conditions in populated areas, taking 

into account sound, emissions, and other factors.

The Forest Service evaluated 21 discrete areas for OSV use designation, within the administrative 

boundaries of the Tahoe National Forest. Two of the areas will not be considered for potential OSV 

designation under any of the alternatives, including the Granite Chief Wilderness (designated by 

Congress as non-motorized) and the North Fork American Wild and Scenic River (not designated for

motorized use in the Tahoe Forest Plan). 

The remaining 19 areas considered for OSV use designation have been reviewed for consistency with 

the Travel Management Rule’s designation criteria (36 CFR 212.55), see Appendix D. The OSV trails 

proposed for designation were also reviewed for consistency with the same criteria, see Appendix E. 

The National Visitor Use Monitoring (NVUM) results, California State Parks, California Outdoor 

Recreation Plan, National Recreation Survey and the Environment information and online visitor 

information sources provided by the Tahoe National Forest and other local organizations and industry 

was used as an overview of the recreation opportunities, visitor use, and trends within the analysis 

area. The Recreation Facility Assessment niche statement was used to depict the importance of winter 

use (motorized or non-motorized) on the national forest; and secondly, consideration was given to 

how important the National Forest System lands are for this use (motorized or non-motorized) 

compared to other non-National Forest System lands. 

The NVUM visitor use information from 2005, 2010, and 2015 was considered. The best available 

site-specific visitor use information for Tahoe National Forest OSV use was from the 2009 OSV 

Winter Trailhead Survey conducted in support of the 2010 State OSV Program EIR for Program Years 

2010−2020. OSV registration information for the State of California and for counties within the 

Tahoe National Forest was also used to depict OSV use trends. 

A case study and literature review of current information regarding motorized and non-motorized 

winter recreation trends and preferences; and coordination with local Forest Service resource 

specialists regarding on-the-ground conditions and use patterns were used to summarize existing 

conditions and potential impacts.

To evaluate potential impacts to recreation settings and opportunities, access, scenery, and designated 

area resources, each alternative will be compared using issues, indicators and measures defined 

below.

Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

59

Resource Indicators and Measures 

Resource indicators and measures shown in table 19 will be used to measure and disclose effects to recreation resources related to OSV use 

designations and grooming trails for OSV use.

Table 19. Resource indicators and measures for assessing effects to recreation resources

Resource Element Resource Indicator Measure

(Quantify if possible)

Source 

(LRMP S&G,5 law or policy, BMPs,6 etc.)?

Motorized Recreation 

Opportunities – cross-country

Opportunities for 

motorized winter uses

Quality of OSV 

opportunities7

Acreage of designated public OSV 

cross-country use; percent change as 

compared to current management

Percent of designated acres that are 

considered high quality OSV 

opportunities based on the high to 

moderate OSV use assumption 

categories

The Tahoe LRMP has a standard and guideline 

pertaining to OSV use for each of its 109 

management areas (MAs), specifying whether all 

or portions of the MA are open to OSV use, closed 

to OSV use, or OSVs are restricted to designated 

rotues only. (TNF LRMP, pp. V-69 through V-544)

Travel Management Rule (36 CFR 212), subpart C.

OSV use assumptions for analysis

Motorized Recreation 

Opportunities – designated 

snow trails

OSV trail designations Length of designated OSV trails (miles), 

percent change from current 

management

Travel Management Rule (36 CFR 212), subpart C.

Motorized Recreation 

Opportunities – groomed snow 

trails

OSV trail grooming Length of groomed OSV trails (miles), 

percent change from current 

management

Travel Management Rule (36 CFR 212), subpart C.

 5 Standard and guideline

6 Best management practices

7 The areas mapped in the high to moderate OSV use assumption categories, shown on Map X, were also assumed to be areas that would provide high quality OSV opportunities. 

The mapped OSV use assumptions were used to compare high-quality OSV opportunities across each alternative. 
Over-snow Vehicle Use Designation 

Tahoe National Forest

60

Resource Element Resource Indicator Measure

(Quantify if possible)

Source 

(LRMP S&G,5 law or policy, BMPs,6 etc.)?

Non-motorized Recreation 

Opportunities - displacement

Access to desired nonmotorized recreation 

settings and opportunities

Quality of non-motorized 

opportunities

Acreage and length of trails (miles) 

designated for non-motorized recreation 

enthusiasts within 5 miles of plowed 

trailheads

Percent of acres available for quiet, 

non-motorized use that are considered 

high quality non-motorized opportunities 

based on proximity to plowed trailheads 

(areas within 5 miles of plowed 

trailheads) and absence of motorized 

use

Public comment

Non-motorized Recreation 

Conflicts – Public Safety

Areas and trails available 

to non-motorized 

recreation enthusiasts for 

quality non-motorized 

recreation experiences

Acreage not designated for public 

cross-country OSV use; percent change 

compared to current management

Minimization Criteria: 36 CFR 212.55(b)(3): 

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; and (4) Conflicts among different 

classes of motor vehicle uses of National Forest 

System lands or neighboring Federal lands. In 

addition, the responsible official shall consider: (5) 

Compatibility of motor vehicle use with existing 

conditions in populated areas, taking into account 

sound, emissions, and other factors

Non-motorized Recreation 

Conflicts – Solitude, Air 

Quality, Scenery, Designated 

non-motorized areas

Solitude Distance of groomed public OSV trails 

from non-motorized areas, number of 

crossings of linear non-motorized 

features.

Wilderness Act of 1964

Wild and Scenic Rivers Act of 1968

National Trails System Act of 1968

Pacific Crest National Scenic Trail Comprehensive 

Plan

Values or features that often characterize 

Inventoried Roadless Areas (66 FR 3245, January 

12, 2001)

Air Quality Qualitative/narrative description of 

potential impacts 

Minimization Criteria: 36 CFR 212.55(b)(3)
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

61

Resource Element Resource Indicator Measure

(Quantify if possible)

Source 

(LRMP S&G,5 law or policy, BMPs,6 etc.)?

Non-motorized Recreation 

Conflicts – Solitude, Air 

Quality, Scenery, Designated 

non-motorized areas

(continued)

Scenery Qualitative/narrative description of 

potential visual impacts

LRMP Management Area Standards and 

Guidelines

Specific Visual Quality Objectives standards and 

guidelines pertain to each management 

area.Visual quality objectives (VQO) include:

Preservation (P), Retention (R), Partial Retention 

(PR), Modification (M), and Maximum Modification 

(MM).

Potential conflict with 

other resource values

Proximity of OSV use related to other 

resource values (such as tribal/ spiritual 

sites, sensitive wildlife areas, popular 

non-motorized winter recreation areas, 

populated areas, neighboring Federal 

lands, etc.).

Minimization Criteria: 36 CFR 212.55(b)(3)

Designated Areas Wilderness Attributes Size of areas (acres) affected and 

duration of impact. Qualitative 

description for wilderness attributes

FSH 1909.12 (72.1)

Roadless Characteristics Size of area (acres) affected and 

duration of impact. Qualitative 

description for roadless characteristics

36 CFR 294.11
Over-snow Vehicle Use Designation 

Tahoe National Forest

62

OSV Use Assumptions for Analysis

The following OSV use assumptions were developed based on information in the California Over-Snow 

Vehicle Program Final State Environmental Impact Report (EIR) for Program Years 2010-2020 and 2009 

Trailhead Survey (conducted in support of the 2010 State OSV Program EIR for Program Years 

2010−2020),, and based on local knowledge and observations of resource specialists from the Tahoe

National Forest. The assumptions were mapped and used in this analysis to consider potential impacts 

from OSV designations and OSV trail grooming activities on recreation and designated areas, and to 

identify areas with high quality, desirable OSV opportunites where OSV use is expected to be in the high 

to moderate range.

The OSV use assumptions include:

• Limited OSV use on steep slopes with heavy forest cover/high tree density (assume no use on 

slopes 35 percent or greater). In open terrain, with no trees, there is no slope-limiting factor for 

high-marking.

• OSV’s avoid open areas with many shrubsuntil snow depth is adequate to cover the schrubs. 

• OSV use patterns: 

♦ Primarily day use (generally 10:00 am to 3:00 pm; grooming occurs at night).

♦ OSV use is at the highest on weekends and holidays. 

♦ Highest concentrations of OSV use occur along groomed trails (this is supported by research 

documented in State EIR).

♦ Concentrated use occurs at trailheads.

♦ Higher OSV use in open meadows (concentrated on meadows with groomed trail access) and 

flatter areas. 

♦ OSV “high marking” occurs primarily on slopes with open vegetation, near groomed trails.

♦ Lower elevations generally have less OSV use – snow occurs at lower elevations less 

frequently and does not persist for long periods of time (2 to 5 days), 5,000 feet and below for 

the Tahoe.

• Ungroomed routes receive 50 percent less OSV use than groomed routes (only 25,000 registered 

OSVs in California per State EIR, most use on groomed trails; if OSV trail grooming were 

discontinued, assume that use would decline by 50 percent). 

• Groomed trails are suitable for OSVs other than snowmobiles (side-by-sides and quads on tracks, 

snowcats, etc.) 

• Groomed trails provide a higher degree of potential receipt of educational messages including 

messages encouraging trail sharing to reduce potential use conflicts. 

Spatial and Temporal Context for Effects Analysis

Spatial Context:

The spatial boundaries for analyzing the direct, indirect, and cumulative effects to recreation are within 

the Tahoe National Forest boundary, because the proposed OSV designation decision would apply to OSV 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

63

trails and areas within the forest boundary and have the potential to cumulatively impact OSV recreation 

experiences and opportunities across the forest.

Effects Timeframe:

The temporal boundaries for analyzing the direct and indirect effects to recreation are, in the short term, 

one year, and in the long term up to 20 years. Short-term effects such as changes in the acres available to 

motorized or non-motorized winter uses would occur upon implementation of the OSV designation 

decision. Long-term effects such as decreases in use conflicts and protection of resources due to effective 

management of OSV use through a designated OSV system of trails and areas would occur over the life 

of the decision

The temporal boundaries for analyzing cumulative effects to recreation are up to 20 years, because the 

OSV designations would remain in effect over the long term, and would therefore overlap in time with 

other forest management activities that could cumulatively impact OSV recreation experiences and 

opportunities.

Affected Environment 

Existing Condition 

Recreation Settings and Opportunities

The Tahoe National Forest is one of the most popular recreation forests in the United States with yearround recreation opportunities. In winter, there are outstanding winter sports opportunities including 

world-renowned downhill ski areas and extensive snowmobile and cross-country ski trails to experience. 

(USDA Forest Service 2016).

The main travel corridors are: Interstate 80, Highway 49, Highway 20, Highway 89 (North and South), 

Foresthill Divide Road, Mosquito Ridge Road, Bowman Road, Marysville Road, and Gold Lake 

Highway. The Tahoe National Forest is bordered on the north by the Plumas National Forest, on the south 

by the Eldorado National Forest, on the east by the Humboldt-Toiyabe National Forests and Lake Tahoe 

Basin Management Unit. On the western border are the foothills above the Sacramento Valley.

Recreation Niche

The recreation niche is a characterization of the distinct role the national forest has in providing outdoor 

recreation opportunities to the public. The niche allows the Forest Service to focus management efforts on 

providing recreation opportunities related to what is unique and valuable about the Tahoe. The recreation 

niche statement of Tahoe National Forest is:

Within a one-hour drive of Reno and Sacramento, the Tahoe National Forest provides visitors the 

opportunity for individual challenge and renewal in a rugged Sierra Nevada setting. Winter and 

summer activities abound; emerging outdoor recreation sports are tested here. World-class 

downhill ski areas can be found nestled in the Tahoe high country; cross-country ski areas 

provide visitors with backcountry winter excursions in fir and pine-canopied landscapes. Other 

popular winter activities include snowplay, snowmobiling and backcountry skiing. With over 

1000 miles of trails, the Tahoe provides California’s most extensive motorized touring and nonmotorized-trekking opportunities in mountainous landscapes. The Tahoe also provides a variety 

of rivers and lakes offering opportunities for waterbased recreation such as fishing, rafting, 

boating and swimming. Campgrounds and other facilities provide visitors lodging and simply a 
Over-snow Vehicle Use Designation 

Tahoe National Forest

64

place to rest after a long day of arduous outdoor-recreation adventure. All of these activities are 

packaged in a scenic setting, surrounded by historic towns and locations that add to the visitor’s 

overall quality experience. It’s Tuesday, take the day off – and come up and enjoy a day on the 

Tahoe! (USDA Forest Service 2007).

Recreation Opportunity Spectrum

The Forest Service uses the recreation opportunity spectrum (ROS) to inventory and describe the range of 

recreation opportunities available based on the following characteristics of an area: physical 

(characteristics of the land and facilities), social (interactions and contact with others), and managerial 

(services and controls provided). The recreational settings are described on a continuum ranging from 

Primitive to Urban. The ROS classes within the Tahoe National Forest include Primitive (P), SemiPrimitive Non-Motorized (SPNM), Semi-Primitive Motorized (SPM), Roaded Natural (RN), and Rural 

(R). OSV designations consistent with the ROS classes provide for a diversity of opportunities for both 

motorized and non-motorized winter activities and the associated desired experiences. The descriptions 

below are from the Tahoe Forest Plan Standards and Guidelines for ROS.

Primitive: Area is characterized by an essentially unmodified natural environment of fairly large size. 

Interaction among users is very low and evidence of other users is minimal. The area is managed to be 

essentially free from evidence of human-induced restrictions and controls. Motorized use within the area 

is not permitted.

Users should have an extremely high probability of experiencing the area as it is described above.

Semi-Primitive Non–Motorized: Area is characterized by a predominantly natural or natural-appearing 

environment of moderate to large size. Interaction among users is low, but there is often evidence of other 

users. The area is managed in such a way that minimum on-site controls and restrictions may be present, 

but are subtle. Public motorized use is not permitted.

Users should have a high, but not extremely high probability of experiencing the area as it is described 

above.

Temporary vehicle use may be authorized based on special needs, but only for the duration of the project, 

roads would then be obliterated. Examples of special needs are insect or fire salvage, vehicle and 

equipment access (supported by an escaped fire situation analysis), and placement or removal of facilities 

under special-use permit.

Semi-Primitive Motorized: Area is characterized by a predominantly natural or natural-appearing 

environment of moderate to large size. Concentration of users is low, but there is often evidence of other 

users. The area is managed in such a way that minimum on-site controls and restrictions may be present,

but are subtle. Public motorized use is permitted. Roads constructed and projects planned for resource 

utilization will strive to maintain the character of the ROS class. Following resource utilization, roads will 

be closed to public use or put-to-bed unless the road meets a specific recreation use in keeping with the 

ROS class.

Users should have a moderate probability of experiencing the area as it is described above, except that 

there is a high degree of interaction with the natural environment. Opportunity is available to use 

motorized equipment while in the area.

Roaded Natural: Area is characterized by a predominantly natural-appearing environment with moderate 

evidences of the sights and sounds of humans. Such evidences usually harmonize with the natural 

environment. Interaction among users may be low to moderate, but evidence of other users is prevalent. 

Resource modification and utilization practices are evident, but harmonize with the natural environment. 

Conventional motorized use is provided for in construction standards and design of facilities.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

65

Users should have about equal probability to either experience affiliation with other user groups or be 

isolated from sights and sounds of people.

Opportunity exist to have a high degree of interaction with the natural environment. Challenge and risk 

opportunities associated with more primitive type of recreation are not very important. Practice and 

testing of outdoor skills might be important. Opportunities for both motorized and non-motorized forms 

of recreation are possible.

Rural: Areas characterized by substantially modified natural environment. Resource modification and 

utilization practices are primarily to enhance specific recreation activities and to maintain vegetative 

cover and soil. Sights and sounds of humans are readily evident, and the interaction between users is often 

moderate to high. A considerable number of facilities are designed for use by large numbers of people. 

Facilities are often provided for special activities. Moderate densities are provided far away from 

developed sites. Facilities for intensive motorized use and parking are available.

Users should be able to experience affiliation with individuals and groups, sites and opportunities are 

convenient. Human Interaction and convenience are generally more important than the setting of the 

physical environment. Opportunities for wildland challenges, risk taking, and testing of outdoor skills are 

generally unimportant except for specific activities like downhill skiing, for which challenge and risk 

taking are important elements.

Modern Urban8

: Areas characterized by a substantially urbanized environment, although the background 

may have natural-appearing elements. Renewable resource modification and utilization practices are 

designed to enhance specific recreation activities. Vegetative cover is often exotic and manicured. Sights 

and sounds of humans, on site, are predominant. Large numbers of users can be expected, both on site and 

in nearby areas. Facilities for highly intensive motor use and parking are available with forms of mass 

transit often available to carry people throughout the site.

Users should be able to experience affiliation with individuals and groups. Sites and opportunities are 

convenient. Experiencing natural environments, having challenges and risks afforded by the natural 

environment, and the use of outdoor skills is relatively unimportant. Opportunities for competitive and 

spectator sports and for passive uses of highly human-influenced parks and open spaces are common.

A majority of Tahoe National Forest acres are in the Roaded Natural and Rural classes.

Table 20. Tahoe National Forest recreation opportunity spectrum classes

Recreation Opportunity Spectrum ROS Class Acres 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 664,122 79%

Total 836,041 100%

Travel Management Plan FEIS Table 3.07-2. ROS acres in each class for all alternatives

Acres and percentage for both Roaded Natural and Rural ROS were combined into a single category.

No Urban ROS designations have been made on the Tahoe National Forest.

 8 Although there is no Modern-Urban ROS Class identified on the Tahoe NF, this Class is presented for comparative purposes.
Over-snow Vehicle Use Designation 

Tahoe National Forest

66

The Granite Chief Wilderness and the North Fork American Wild River, the only Primitive ROS areas,

are closed to public OSV use. The ROS classes are incorporated into the Tahoe Forest Plan management 

areas. 

Motorized Winter Recreation

The Tahoe National Forest receives adequate snowfall for OSV trail grooming in all four Ranger 

Districts, however the east side of the forest (Truckee and Sierraville districts) receives the most snow and 

has a longer grooming season. Snowmobile use is managed under the Tahoe Off-Highway Vehicle Travel 

Plan and the Transportation Management Program.

OSV use is prohibited in the Granite Chief Wilderness, Research Natural Areas, North Fork American 

River Wild and Scenic River and the Onion Creek Experimental Forest. Forest Plan standards and 

guidelines for each of the Forest’s 109 management areas specify OSV use designations (open to OSV 

use, closed to OSV use, or restricted to designated routes) for each management area. (Refer to Appendix 

B. Forest Plan Direction.)

There are four Snowmobile Outfitter/Guides currently permitted to operate on the Tahoe National Forest, 

including Eagle Ridge Snowmobile Outfitters (Little Truckee Summit), Coldstream Adventures (Cabin 

Creek and Coldstream), Lake Tahoe Snowmobiling (Brockway Summit and Hwy 267), and Full Throttle 

(Martis Peak Road and Highway 267) (USDA Forest Service 2010).

For over 30 years, the Forest Service, Pacific Southwest Region, in cooperation with the California 

Department of Parks and Recreation (California State Parks) Off-highway Motor Vehicle Division has 

enhanced winter recreation, and more specifically, snowmobiling recreation by maintaining National 

Forest System trails by grooming snow for snowmobile use. Plowing of local access roads and trailhead 

parking lots, grooming trails for snowmobile use, and light maintenance of facilities (e.g., restroom 

cleaning, garbage collection) are the essential elements of the OSV program that keep the national forests 

open for winter recreation use. 

There are approximately 265 miles of National Forest System OSV trails on the Tahoe National Forest, 

with approximately 217 miles of these available for grooming. There are six designated winter trailheads 

that include three SnoParks (Yuba Gap, Donner Summit, and Yuba Pass), restroom facilities, three Snow 

Tractor/Groomer storage sheds (Little Truckee Summit on the Sierraville Ranger District, Bassett’s on the 

Yuba River Ranger District, and China Wall on the American River Ranger District). All grooming is 

done on top of the designated road system. The groomed OSV trail system that is included in the 

California Department of Parks and Recreation, OSV Program funded activities on the American River, 

Yuba River, Truckee, and Sierraville Ranger Districts is described below. 

Bassetts Trail System. The Bassetts trail system and trailhead parking are located off State Route 49 

roughly 15 miles west of Sierraville in the Yuba River Ranger District. Trailhead parking is provided off 

Gold Lake Road. Some of the Bassett area trails extend north to the Gold Lake area in the Plumas 

National Forest. Bassetts provides 82 miles of groomed trail (including county roads). Trails connect to 

the Little Truckee Summit trailhead. Trail elevations range from 5,700 feet to 7,800 feet. The Bassetts 

trail system is located within the Yuba Northeast and Sierraville West OSV areas on the Tahoe National 

Forest. Detailed OSV route mileage on Tahoe National Forest lands is shown in table 22.

China Wall Trail System. The China Wall trail system and trailhead parking are located 12 miles 

northeast of Foresthill on Foresthill Road off of Interstate 80 near Auburn. Trailhead parking is provided 

via a parking lot accessed from Foresthill Road. The China Wall trail system provides 50 miles of 

groomed trail (including County roads), a plowed trailhead, and a restroom maintained by the Forest 

Service (American River Ranger District). Trail elevations range from 5,000 feet to 7,200 feet. Unmarked 

routes follow Foresthill Road from which riders can take side trips to Humbug, Deadwood, and American 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

67

Hill ridges. The groomed trails include the China Wall Staging Area to Road 66, Humbug Loop, 

Foresthill Divide Road, American Hill Loop (Road 13), Ford Point Trail and Tadpole Loop, Soda Springs 

Trail, and Duncan Y trail (Road 43). The China Wall trail system is located within the Foresthill East 

OSV area on the Tahoe National Forest. Detailed OSV route mileage on Tahoe National Forest lands is 

shown in table 22.

Placer County plows 3 miles of Foresthill Road and the trailhead parking.

Little Truckee Summit Trail System. The Little Truckee Summit trail system is accessed from three 

different trailhead parking areas: Yuba Pass Sno-Park on State Route 49 eight miles west of Sierraville; 

Little Truckee Summit on State Route 89 at Jackson Meadow Road roughly 16 miles north of Truckee; 

and Prosser Hill five miles north of Truckee. 

Little Truckee Summit offers 138 miles of groomed trail (including County roads) with elevations 

ranging from 5,700 feet to 7,800 feet. Snowmobile trail grooming is done by a private contractor through 

the Sierra County Public Works and Transportation Department. Some snowmobile trail grooming is 

done under Forest Service volunteer agreements by private landowners living year-round off the groomed 

trail system. Plowed trailhead access is provided by Caltrans at all three trailheads; however only the 

Little Truckee Summit trailhead is plowed by State of California OSV Program funds under contract to 

Sierra County. 

In the spring, temporary trailheads are set-up along the main groomed snowmobile route by plowing 

Jackson Meadow Road (Forest Route 07) out of Little Truckee Summit, to help provide better access for 

OSV riders and decrease damage to the Jackson Meadow Road. Plowing of Jackson Meadow Road has 

historically been done by private contractor through Sierra County, however, in 2010, plowing was done 

by Sierra County. Winter restroom cleaning and maintenance at all three locations is done with a 

combination of Forest Service (Tahoe National Forest) OHV Ground Operations funds (Prosser Hill), 

sno-park funds (Yuba Pass Sno-Park), and State of California OSV Program funds through Sierra County 

(Little Truckee Summit). The Little Truckee Summit trail system is located within the Sierraville West 

OSV areas on the Tahoe National Forest. Detailed OSV route mileage on Tahoe National Forest lands is 

shown in table 22.

Table 21. Overview of State of California OSV Grooming Program Activity on the Tahoe National Forest

Project Location

National Forest (NF), Ranger 

District, and County

Recreation Facility State of California OSV Program Funded 

Activity

Tahoe NF, Yuba River Ranger 

District, Sierra County, near 

Bassetts

Bassetts and Little 

Truckee Summit Trail 

Systems

Groom 82 miles of trail, plow 13 miles of road 

and 2 trailheads, and service restrooms.

Tahoe NF, American River Ranger 

District, Placer County, near Auburn

China Wall Trail System Groom 50 miles of trail, plow 3 miles of road 

and 1 trailhead, service 1 restroom, and 

refuse collection.

Tahoe NF, Sierraville and Truckee 

Ranger Districts (East Zone), Sierra 

and Nevada counties

Little Truckee Summit, 

Prosser, and Yuba Pass 

groomed trail systems

Groom 138 miles of trail (connects to 

Bassetts/Gold Lakes), plow 8 miles of road 

and 1 trailhead (2 plowed by Caltrans), 

service 3 restrooms
Over-snow Vehicle Use Designation 

Tahoe National Forest

68

Table 22. Overview of OSV Trails on Tahoe National Forest Lands

Tahoe National 

Forest OSV 

Area

Groomed OSV 

Trail Systems

Designated 

OSV Trails 

Available for 

Grooming 

(miles)

Marked, 

Ungroomed 

Trails for OSV 

Use (miles)

Designated 

OSV trails not 

Available for 

Grooming 

(miles)

Total OSV Trail 

miles on Tahoe 

National Forest 

Lands

Black Buttes 12 12

Bowman 14 14

Donner Summit 2 1 3

Foresthill East China Wall 55 21 0.5 76.5

Sierraville West Little Truckee 

Summit and 

Bassets

114 114

Truckee 1 6 5 12

Yuba Northeast Bassets 21 11 1 33

Tahoe National 

Forest OSV 

Area

Groomed OSV 

Trail Systems

Designated OSV 

Trails Available 

for Grooming 

(miles)

Marked, 

Ungroomed 

Trails for OSV 

Use (miles)

Designated OSV 

trails not 

Available for 

Grooming 

(miles)

Total OSV Trail 

miles on Tahoe 

National Forest 

Lands

Non-motorized Winter Recreation

The Tahoe National Forest contains one designated wilderness (28,475 acres), 11 inventoried roadless 

areas (171,328 acres), one designated and four recommended Wild and Scenic Rivers, three research 

natural areas, and two experimental forests. 

The non-motorized Pacific Crest National Scenic Trail follows the Sierra Crest through the middle of the 

Tahoe National Forest, and the non-motorized South Yuba National Recreation Trail follows the South 

Fork of the Yuba River.

There are five cross-country ski areas including Lunch Creek, Castle Peak, Kyburz, Cabin Creek and Pole 

Creek.

Designated Areas 

Wilderness

The California Wilderness Act of 1984 designated the Granite Chief Wilderness on the Tahoe National 

Forest. The Wilderness is adjacent to the western watershed boundary of Lake Tahoe and includes Five 

Lakes Creek and the headwaters of the North Fork and Middle Fork of the American River. The major 

attractions of this area are its high, rugged granite cliffs and broad glaciated valleys. (USDA Forest 

Service 2007, p 36).

The Wilderness Act of 1964 prohibits OSV use in designated wilderness areas. The nearest marked OSV 

route to the Granite Chief Wilderness is the Mosquito Ridge trail, located more than two air miles to the 

west of the Wilderness boundary.

Inventoried Roadless Areas:

Inventoried roadless areas (IRA) provide clean drinking water and function as biological strongholds for 

populations of threatened and endangered species. They provide large, relatively undisturbed landscapes 

that are important to biological diversity and the long-term survival of many at-risk species. Inventoried 

roadless areas provide opportunities for dispersed outdoor recreation, opportunities that diminish as open 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

69

space and natural settings are developed elsewhere. They also serve as bulwarks against the spread of 

non-native invasive plant species and provide reference areas for study and research (USDA Forest 

Service 2009).

Tahoe National Forest has 11 inventoried roadless areas totaling 171,328 acres (Tahoe National Forest, 

GIS data), excluding private lands located within the IRA boundaries. The names and acres of each IRA 

are listed in table 23. Detailed descriptions of the roadless area characteristics can be found in the 1990 

Forest Plan FEIS appendix G, and in the 2010 Tahoe Motorized Travel Management FEIS. 

Table 23. Tahoe National Forest inventoried roadless areas

Inventoried Roadless Area Acres OSV Status

Bald Mountain (extends onto 

the Humboldt-Toiyabe NF)

5,834 Approximately 1,061 acres of this IRA has been established as a 

Research Natural Area. OSV use prohibited within the SPNM and 

RNA portion, OSV use allowed or restricted in remaining acreage. No 

OSV trails in this area. 

Castle Peak 15,738 The Andesite West OSV trail passes through the western side of the 

Castle Peak IRA. OSV use is prohibited in the Independence 

Zoological SIA in the northeast portion of the IRA.. OSV use is 

allowed or restricted on the remaining acreage. This area receives

heavy cross-country skiing and snowmobile use in the winter. There 

are areas of high to moderate OSV use in this IRA.

Duncan Canyon 9,253 The Mosquito Ridge, Robson Flat, Duncan Y and Soda Springs OSV 

trails form a loop around the Duncan Canyon IRA, but are not within 

the IRA acreage. OSV use is allowed within this IRA. There are areas 

of high to moderate OSV use in this IRA.

East Yuba 10,805 The Gold Valley Marked snowmobile trail is located in the SW portion 

of the East Yuba IRA. OSV use is allowed within this IRA. There are 

areas of high to moderate OSV use in this IRA.

Granite Chief (Granite Chief 

Wilderness acreage included)

31,297 The California Wilderness Act of 1984 designated 25,680 acres of 

this IRA as the Granite Chief Wilderness. OSV use is prohibited in 

the designated Wilderness, and in the SPNM areas of the IRA 

adjacent to the Wilderness. No OSV trails in this area. 

Grouse Lakes (Grouse Lake 

vehicular closure included)

19,271 OSV use is allowed within this IRA. No OSV trails in this area. There 

are areas of high to moderate OSV use in this IRA.

Lakes (Basin) (extends onto 

the Plumas NF)

557 The Gold Valley Marked snowmobile trail is located just outside of 

this IRA, within the East Yuba IRA. OSV use is allowed in this area.

Middle Yuba 7,884 Over 40 percent of this IRA is in private ownership. OSV use is 

allowed in a majority of this IRA. No OSV trails in this area. 

North Fork American River 

(NFAR Wild River included)

43,374 The Soda Springs, Foresthill Divide, American Hill, Tadpole, Ford 

Point, Humbug, and Humbug Tie OSV trails run near the southern 

boundary of the North Fork American River IRA, but are not within 

the IRA or WSR acreage. OSV use is prohibited in a majority of this 

IRA. OSV use is low in this IRA.

North Fork of the Middle Fork 

American River

11,257 OSV use is allowed in a majority of this IRA. No OSV trails in this 

area. 

West Yuba (extends onto the 

Plumas NF)

1,605 OSV use is allowed in a majority of this IRA. No OSV trails in this 

area. 

Wild and Scenic Rivers:

The North Fork American Wild River is classified by Congress and administered according to the North 

Fork American Wild River Management and Development Plan. Visual quality is managed according to
Over-snow Vehicle Use Designation 

Tahoe National Forest

70

standards and guidelines in the Tahoe National Forest Land and Resource Management Plan (LRMP 

1990)

Four river corridors on the Tahoe National Forest have been recommended for designation as Wild and 

Scenic Rivers. The proposed corridors include sections of Sagehen Creek, Canyon Creek, North Yuba 

River, and the Lower South Yuba River. The proposed segments are managed to protect their wild and 

scenic characteristics through the study period and until designated or released from consideration. 

The Bowman OSV trail passes through a recommeneded scenic segment of the South Yuba River. The 

Fifty Four Road trail crosses a recommended recreational segment of the North Yuba River. The Prosser 

Creek Connector trail crosses a recommended scenic segment of Sagehen Creek.

Research Natural Areas

There are three research natural areas (RNAs) on the Tahoe National Forest that are managed to maintain 

select vegetative, aquatic, and/or geologic elements in natural conditions. Babbit Peak RNA (within the 

Bald Mountain IRA), Sugar Pine RNA (a portion of the RNA is in the North Fork American River IRA), 

and Lyon Peak Needle Lake RNA (within the Granite Chief IRA) are not designated for OSV use under 

existing Forest Plan standards and guidelines.

Experimental Forests

There are two experimental forests within the Tahoe National Forest. Experimental forests provide lands 

for conducting research and development that serves as a basis for the management of forests and 

grasslands. 

Special Interest Areas

There are eight special interest areas 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. OSV use is 

not designated in a majority of the special interest areas, with the exception of Sagehen Headwaters and 

Meadow Lake Special Interest Areas.

Pacific Crest National Scenic Trail

Approximately 99 miles of the PCT traverse the Tahoe National Forest. Of that, 76 miles of the PCT is on 

National Forest System lands. OSV use along the PCT is prohibited by the National Trails System Act, 

P.L 90-543, Section 7(c). The PCT is managed for non-motorized trail uses.

The PCT was designated in 1968 as one of the first national scenic trails. The PCT (extending from 

Mexico to Canada) was established to provide for maximum outdoor recreation potential and for the 

conservation and enjoyment of the nationally significant scenic, historic, natural, or cultural qualities of 

the areas which such trails may pass (USDA Forest Service 192).

The Pacific Crest National Scenic Trail Comprehensive Management Plan (1982) contains the following 

direction:

Viewing and understanding resource management are considered to be part of the normal 

character of the trail. The management of the various resources will give due consideration to the 

existence of the trail and trail users within the multiple use concept. Prescription for management 

of the visual resources associated with the trail will be part of agency planning processes.

The Comprehensive Management Plan reinforces that snowmobiling along the trail is prohibited and has 

the following direction for implementation of the Plan:
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

71

Winter Use: Winter use (cross country skiing and snowshoeing) should be accommodated where 

practical and feasible. Each agency should follow its own procedures for marking and signing 

the trial for winter use purposes. As a guideline, all trail markers should be at eye level 

(approximately 40” above average maximum snow depth). Sanitation facilities and snow 

removal for parking may be necessary. Any improvement or alterations of the vegetation should 

not detract from the quality of the recreation opportunities for other trail activities such as hiking 

and horseback riding.

Snowmobiling along the trail is prohibited by the national Trail System Act, P.L. 90-543, Sec 

7(c). Winter sports plans for areas through which the trail passes should consider this 

prohibition in determining areas appropriate for snowmobile use. Winter sports brochures 

should indicate designated snowmobile crossing of the Pacific Crest Trail where it is signed and 

marked for winter use. If cross-country skiing and/or snowshoeing are planned for the trail, any 

motorized use of adjacent land should be zoned to mitigate the noise of conflict.

Management areas that are crossed by the PCT have this specific direction referenced as part of their 

prescription in the Forest Plan. 

The Tahoe Forest Plan includes the following under Management Goals and Strategies for Facilities

(transportation system):

3. Manage Tahoe National Forest lands next to the Pacific Crest National Scenic Trail under the 

multiple use concept, giving due consideration to the existence of the trail and users of the trail

(LRMP, pg. V-11).

Approximately one-quarter of the PCT mileage on the Tahoe passes through wilderness and other areas 

where OSV use is not designated for OSV use. The remaining mileage passes through areas that are 

designated for OSV use, however OSV use is not allowed on the Trail itself. Existing groomed and 

marked OSV trails cross the PCT in four locations, however no designated crossings have been identified.

Visitor use

To determine possible effects of management alternatives, it is important to understand the characteristics 

of people who visit and recreate on the Tahoe National Forest. Responding to the need for improved 

information about visitors to National Forest System lands, the Forest Service developed a nationwide, 

systematic monitoring process for estimating annual recreation use: the National Visitor Use Monitoring 

(NVUM) program.

The NVUM program was designed to provide statistically reliable estimations of recreation visitation to 

national forests and grasslands. Through collection and dissemination of information about recreational 

visitors and their preferred activities, resource managers can make informed, strategic decisions about the 

types and amount of recreation opportunities provided on the national forest.

NVUM surveys were conducted on the Tahoe National Forest during fiscal years 2005, 2010, and 2015. 

Surveys collected information about participation in recreation activities, visitor demographics, and 

spending patterns. Summaries from these surveys are useful to describe recreation use patterns on the 

national forest. As displayed, these data are only valid at the forest level and cannot be disaggregated to 

specific sites or locations.

Local visitors are common to the Tahoe National Forest. Over 40 percent of visits came from people 

living within 25 miles of the national forest; and less than 10 percent have traveled over 200 miles. About 

half of all visits to the Tahoe National Forest last less than 4 hours. Frequent visitors are relatively 

common with over 35 percent of all visits made by people who visit more than 50 times per year.
Over-snow Vehicle Use Designation 

Tahoe National Forest

72

In 2015, the three most reported main activities were downhill skiing (23 percent), hiking/walking 

(20 percent), and viewing natural features (8 percent). In 2010, the three most reported main activities 

were downhill skiing (18 percent), hiking (13 percent), and cross-country skiing (13 percent). In 2005, the 

three most reported main activities were downhill skiing (31 percent), hiking (15 percent), and fishing 

(11 percent). In 2015, snowmobiling was reported as a main activity for 0.2 percent, in 2010, 

snowmobiling was reported as a main activity for 1.7 percent, and in 2005 snowmobiling was reported as 

a main activity for 7 percent.

Table 24 shows the estimated visitor use based on the percentage of visitors reporting snowmobiling and 

cross-country skiing as their main activity. 

Table 24. National Visitor Use Management winter activities 

Year Activity

Total Annual 

National 

Forest Visits

% Main 

Activity

Estimated Annual National 

Forests Visits based on the 

% main activity

Average hours 

participating in 

main activity

2015 Snowmobiling 1,660,000 0.2% 3,320 3.5

2015 Cross-country Skiing 1,660,000 5.7% 94,620 3.0

2010 Snowmobiling 1,847,000 1.7% 31,399 3.1

2010 Cross-country Skiing 1,847,000 12.6% 232,722 3.5

2005 Snowmobiling 1,696,000 7.0% 118,720 3.9

2005 Cross-country Skiing 1,696,000 12.6% 213,696 3.5

*A National forest visit is defined as the entry of one person upon a national forest to participate in recreation activities for an 

unspecified period of time. A national forest visit can be composed of multiple site visits. The visit ends when the person leaves the 

national forest to spend the night somewhere else.

The California Department of Motor Vehicles records OSV registration by county each year. The Tahoe

National Forest falls within the five counties shown in table 25.

Table 25. California OSV registration for counties in Tahoe National Forest, 2009 through 2014

County 2009 2010 2011 2012 2013 2014

Nevada 1,037 1,066 1,023 1,020 1,041 1,030

Placer 1,407 1,291 1,252 1,199 1,165 1,127

Plumas 1,236 1,180 1,111 1,025 1,022 920

Sierra 223 220 205 208 207 192

Yuba 340 351 325 300 310 303

TOTAL 4,243 4,108 3,916 3,752 3,745 3,572

*Data from CA State Parks, not official DMV records

Table 26 shows total statewide OSV registrations and out-of-state registrations.

Table 26. California statewide OSV registration, 2009 through 2014

2009 2010 2011 2012 2013 2014

Subtotal 18,542 17,982 17,776 16,956 16,929 16,189

Out of State 260 242 235 244 215 197

Total 18,802 18,224 18,011 17,200 17,144 16,386

*Data from CA State Parks, not official DMV records
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

73

Snowmobile registrations in the Tahoe National Forest counties and statewide have declined slightly over 

the past six years. The State EIR estimated that OSV use would continue to increase at a rate of 

approximately 4 percent per year, as it had between 1997 and 2009 (California Department of Park and 

Recreation 2010); however, that has not been the case in recent years. 

Because the Tahoe National Forest is near several large metropolitan areas in northern California and 

Nevada, and high-use areas around Lake Tahoe, demand for a variety of year-long recreation 

opportunities is high. It is projected that recreation on the forest would, at a minimum, increase at the 

same rate as the projected population in the surrounding counties (USDA Forest Service 2007). OSV 

visitor use varies based on the amount of snowfall and the length of the season. 

Table 27 is derived from the OSV trailhead survey conducted for the State EIR, and based on data 

summarized in the State EIR (California Department of Park and Recreation 2010). The table shows the 

average number of vehicles at winter trailheads, and the average number of OSVs that would be expected 

on weekends and holidays versus weekdays. Based on this information, estimated use per winter season 

would be 22,410 OSV users forestwide. 

Table 27. Tahoe National Forest OSV visitor use

Location Day description Number of vehicles Number of OSVs*

Forestwide

Weekend or holiday 

(approx. 33 per 

season)**

202 404

Forestwide Weekday

(approx. 65 per 

season)**

40 80

Forestwide (other non-program 

parking)

Weekend or holiday 43 86

Forestwide (other non-program 

parking)***

Weekday 8 16

Visitor Use information split out by trailhead:

Bassetts Trailhead Weekend or holiday 30 30

Bassetts Trailhead Weekday 8 7

Little Truckee Summit Trailhead Weekend or holiday 140 280

Little Truckee Summit Trailhead Weekday 17 34

China Wall Trailhead Weekend or holiday 32 64

China Wall Trailhead Weekday 16 32

Based on 2009 data from California State Draft EIR

*assumes an average of 2 OSVs per vehicle parked at a trailhead

**seasonal total assumes 33 weekends/holidays of observed maximum total and 65 weekdays at 20 percent capacity.

*** Non-program parking is parking used by winter OSV visitors that is not one of the California State OSV Program-funded 

trailheads

Conflicts between Motorized and Non-motorized Winter Experiences

The 2015 NVUM report indicates that 80.6 percent of visitors to the Tahoe National Forest are very 

satisfied, and 14.5 percent are somewhat satisfied. The satisfaction survey questions did not directly 

address winter use, however, the NVUM Importance-Performance ratings for Undeveloped General 

Forest Areas that could be relevant to winter recreation include conditions of developed facilities, access, 

service, and feeling of safety, all were rated “keep up the good work” (USDA Forest Service 2015).
Over-snow Vehicle Use Designation 

Tahoe National Forest

74

Both motorized and non-motorized winter recreation activities can be described in three general 

categories including trail touring, backcountry exploring, and alpine adventure (Snowlands 2015). Trail 

touring is typically focused on the use of groomed trail systems, where the quality of the groomed trail 

with moderate climbs and descents is often the most important factor for the recreation experience. 

Backcountry exploring is focused on cross-country travel away from the groomed trail system with 

emphasis on travelling and exploring. Alpine adventure is characterized by the challenge of riding or 

skiing through powder snow on steeper slopes. In alpine adventure, backcountry skiers seek the downhill 

experience, while snowmobilers enjoy the challenge of climbing up (Snowlands 2015). Of particular 

concern for conflicts between motorized and non-motorized winter uses are areas that can be accessed in 

the winter from the Forest’s six winter trailheads: Yuba Gap, Donner Summit, Yuba Pass, Little Truckee 

Summit, Bassett’s, and China Wall. Most winter recreationists (both motorized and non-motorized) 

launch their winter recreation activities from these six designated winter trailheads.

Opportunities for quality recreation experiences depend on both the settings (physical, social, and 

managerial aspects), and on the desired experience of the recreationist. Conflicts occur when one 

recreationist effects or degrades the experience of another. Many non-motorized recreationists experience 

conflict with motorized recreationists (Adams and McCool 2010). Conflict can result in displacement or 

the abandonment of the use of a particular trail or area, or a change in time of use (Adams and McCool 

2010).

Conflict between motorized and non-motorized winter uses arise due to differing desired recreation 

experiences, public safety concerns, noise, air quality, and access issues. Public comments received 

during the scoping period for this project describe conflicts related to (1) displacing visitors who prefer 

non-motorized recreation opportunities; (2) posing safety concerns for non-motorized users due to the 

high speed of vehicles on shared trails; (3) creating noise and air quality impacts that lead to the 

displacement of non-motorized users; (4) quickly consuming untracked powder snow, which reduces a 

desired backcountry skiing experience; (5) disrupting ski tracks, making the snow surface unsuitable for 

cross-country skiing; and (6) grooming trails which the State of California’s Over Snow Vehicle Program 

Draft EIR estimates triples public OSV use on trails to the detriment of non-motorized users.

In public comments received during the scoping period for this project, motorized winter enthusiasts 

expressed concerns regarding additional limitations on use; however, they generally did not describe 

conflicts with non-motorized uses. Snowmobile trails are typically available for multiple uses, and in 

some areas provide opportunities for non-motorized uses such as cross country skiing, snowshoeing, and 

winter mountain biking. There are also those who use snowmobiles as a means to access backcountry 

areas to participate in non-motorized activities (American Council of Snowmobile Associations 2014). 

There are approximately 25,000 annual OSV registrations in the state of California, and according to the 

2009 State DEIR trailhead survey, approximately 22,410 OSV visits forestwide per winter season, 

typically mid-December through March. OSV use would be spread across the available areas and trails 

designated for OSV use. Based on 22,410 visits, if use were spread evenly across each day of the season, 

there would be approximately 213 OSVs on the forest per day. Daily use may be higher during weekends 

and holidays and lower during the week. For the existing conditions, this equates to 2,995 acres and 1 

mile of trail per OSV. The level of OSV use is relatively low in comparison to other winter activities and 

there is adequate acreage available for the OSV use to disperse and avoid conflict.

Quality non-motorized winter recreation experiences are typically characterized by quiet activities such as 

cross-country skiing or snow-shoeing in a natural environment that is not influenced by the sound, smell 

of exhaust, or sight of snowmobiles. Areas must be accessible from plowed trailheads, as non-motorized 

recreationists typically do not travel long distances. Most non-motorized over snow recreation takes place 

within three to five miles of trailheads (American Council of Snowmobile Associations 2014). Nonmotorized visitors spend an average of 2.3 hours on the snow per visit (Rolloff et al. 2009).
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

75

Quality motorized winter recreation opportunities are typically characterized by groomed trail systems 

and open hills for high marking. For this analysis, OSV opportunites across the Tahoe NF were mapped 

based on the OSV use assumptions criteria (listed in the Methodology section above). The areas that fall 

within the high to moderate OSV use areas are considered to provide high quality OSV opportunities 

based on the proximity to groomed trails and plowed trailheads, open meadows with trail access, and

slopes with open vegetation near groomed trails. Snowmobilers typically have a maximum 80-mile 

round-trip travel range (California Department of Parks and Recreation 2010). Approximately half of 

motorized visitors indicated that they would not snowmobile or would snowmobile less if the trails were 

not groomed (Rolloff et al. 2009). OSV visitors spend an average of 6 hours on the snow per visit. 

Motorized recreationists are also interested in travelling through and experiencing a natural environment.

Environmental Consequences

Alternative 1

Direct and Indirect Effects

Recreation Settings and Opportunities

OSV use would continue to be managed according to the Tahoe Forest Plan. No changes to the OSV 

designations would be made, the existing winter motorized and non-motorized recreation opportunities 

would continue to be available. Grooming would continue as described in the 2010 State EIR, based on 

availability of funding, and adequate snowfall. There would be no reduction of opportunities or change in 

location for winter motorized OSV use.

The 2005 Travel Management Rule, subpart C, would not be implemented, and no OSV use map would 

be produced.

Opportunities for winter non-motorized recreation would also remain the same as described in the 

existing conditions. OSV use would remain consistent with existing ROS classes, with motorized use 

prohibited in Primitive and Semi-Primitive Non-motorized ROS classes (with the exception of the Grouse 

Management Area (041) and a small portion of the Sunflower Management Area (091)where OSV use is 

allowed in the winter) and allowed in Semi-Primitive Motorized, Roaded Natural and Rural ROS classes. 

OSV use is not allowed on the PCT and there are no designated OSV.

Conflicts between Motorized and Non-motorized Winter Experiences

Existing areas of conflict between motorized and non-motorized winter uses would continue. Most crosscountry skiing occurs in the Snow Belt above 5,300 feet in elevation, and most use would occur within 

five miles of an all-weather road that is cleared of snow during the winter (USDA Forest Service 2007). 

These areas are most likely to see conflict between motorized and non-motorized winter uses. There are 

approximately 25,000 annual OSV registrations in the state of California, and according to the 2009 State 

DEIR trailhead survey, approximately 22,410 OSV visits forestwide per winter season, typically midDecember through March. OSV use would be spread across the available areas and trails that are 

designated for OSV use. 

Non-motorized winter recreation enthusiasts may continue to be displaced in some areas by motorized 

OSV use. Displacement or conflict may occur where non-motoirzed enthusiasts are unable to access areas 

for desired quiet, non-motorized experiences away from the sights, sounds, and smells of motorized use, 

without traveling long distances through motorized routes and areas, or traveling further than they are 

physically able to traverse in a typical day. There are approximately 89,667 acres available for high 
Over-snow Vehicle Use Designation 

Tahoe National Forest

76

quality, quiet, non-motorized winter activities and approximately 28 miles of cross-country ski trails and 

20.5 miles of the PCT within 5 miles of plowed trailheads. These areas are free from motorized use and 

are easily accessible by non-motorized visitors in a typical day trip. There are approximately 198,271 

acres across the Forest available for quiet, non-motorized experiences, where OSV use is not designated. 

There are also 1,218 acres designated for public cross-country OSV use in deer holding areas from 

January 1 through September 14, allowing opportunities for quiet, non-motorized recreation in these areas 

when OSVs are not present.

Other potential conflicts would continue to occur in some areas, as motorized OSVs consume untracked 

powder snow that is desired by backcountry skiers, create tracks across the snow surface making skiing 

difficult, and creating safety concerns in areas where motorized and non-motorized use is occurring at 

shared trailheads and on shared trails.

Designated Areas

OSV use within the Granite Chief Wilderness is prohibited by the Wilderness Act. The closest OSV trail 

to the wilderness boundary is the Mosquito Ridge OSV trail, located more than two miles to the west. 

OSV incursions have not been an issue in this area. 

OSV use is allowed on approximately 109,234 acres within inventoried roadless areas. Portions of the 

East Yuba, Lakes Basin, Grouse Lakes, Castle Peak, and Duncan Canyon Inventoried Roadless Areas are 

open to OSV use and are in areas where moderate to high OSV use occurs near the groomed trail system. 

Portions of five other inventoried roadless areas also fall in areas open to OSV use; however, low to no 

OSV use is expected in these areas. OSV use is prohibited in the Granite Chief IRA, including the 

designated Wilderness acreage. The roadless characteristics of high quality or undisturbed soil, water, 

and air, and solitude may be temporarily impacted when OSVs are present. 

The Pacific Crest National Scenic Trail (PCT) would continue to be managed as a non-motorized trail, 

however OSV use adjacent to the trail could impact the winter non-motorized trail experience due to 

noise and the presence of OSVs near the trail, or crossing the trail. OSV trails across the PCT would not 

be designated and OSVs would continue to cross the trail along existing OSV routes, and could cross the 

PCT at any location where the trail passes through an area where OSVuse is allowed. The portion of the 

PCT on the Tahoe National Forest that passes through the Granite Chief Wilderness and other areas where 

OSV use is currently prohibited would continue to provide opportunities for quite non-motorized trail 

experiences.

Ongoing motorized use in close proximity to areas managed as non-motorized and inventoried roadless 

areas temporarily degrades opportunities for solitude when OSVs are present. Similarly, there may be 

temporary impacts to air quality from exhaust in the vicinity of OSVs, and short-term impacts to scenery 

when OSV tracks through the snow crisscross the landscape, leaving visual evidence of motorized use. 

The tracks only remain on the landscape until they are covered by additional snowfall or until the snow 

melts, and do not cause long-term impacts to scenery or the underlying soils and vegetation.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

77

Table 28. Recreation resource indicators and measures for the existing condition, alternative 1

Resource Element Resource Indicator Measure

(Quantify if possible)

Existing Conditions

Motorized Recreation 

Opportunities –

cross-country

Opportunities for motorized 

winter uses

Quality of OSV 

opportunities

Size of areas (acres) designated 

for to public OSV use

Percent of designated acres that 

are considered high quality OSV 

opportunities based on the high to 

moderate OSV use assumption 

categories

638,002 acres open for OSV use

33 percent of the acres open for OSV use provide high quality 

OSV opportunities. This totals to approximately 212,857 acres.

No minimum snow depth for OSV use cross-country

Motorized Recreation 

Opportunities –

designated snow 

trails and snow trails 

available for 

grooming

OSV trail designations Length (miles) of designated OSV 

trails available for 

grooming/Length (miles) of 

marked snow trails (ungroomed)

217 miles designated OSV trails available for grooming; 

41 marked, ungroomed trails designated for OSV use

No minimum snow depth for OSV use on trails

Follow OHMVR snow depth standards (for snow trail grooming to 

occur using OHMVR division funds/equipment) 

Non-motorized 

Recreation 

Opportunities -

displacement

Access to desired nonmotorized recreation 

settings and opportunities

Quality of non-motorized 

opportunities

Size of area (acres) and length of 

trails (miles) available to nonmotorized recreation enthusiasts 

within 5 miles of plowed trailheads

Percent of acres available for 

quiet, non-motorized use that are 

within desired areas (defined as 

areas within 5 miles of plowed 

trailheads)

89,667 acres and 28 miles of cross-country ski trails and 20.5 

miles of the PCT available for non-motorized recreation within 5 

miles of plowed trailheads

45 percent of the acres not designated for OSV use (available for 

quiet, non-motorized use) provide high quality non-motorized 

opportunities, within 5 miles of plowed trailheads. 

Recreation Opportunity 

Spectrum

Consistency of OSV designations 

and grooming with existing ROS 

classes

Motorized OSV use prohibited in Primitive and Semi-Primitive 

Non-Motorized ROS classes9. Motorized OSV use allowed in 

Semi-Primitive Motorized, Roaded Natural and Rural ROS 

classes

 9 With the exception of the Grouse Management Area (041) and a small portion of the Sunflower Management Area (091).
Over-snow Vehicle Use Designation 

Tahoe National Forest

78

Resource Element Resource Indicator Measure

(Quantify if possible)

Existing Conditions

Non-motorized 

Recreation Conflicts 

– Public Safety

Areas and trails available to 

non-motorized recreation 

enthusiasts for quality nonmotorized recreation 

experiences

Size of areas (acres) OSV use not 

designated 198,271 acres not designated for OSV use

1,218 acres OSV use allowed between January 1 and September 

14

Non-motorized 

Recreation Conflicts 

– Solitude, Air 

Quality, Scenery, 

Designated nonmotorized areas

Proximity and frequency of 

OSV designations in 

relation to designated nonmotorized areas

Distance of groomed public OSV 

snow trails from designated areas, 

number of OSV trails across linear 

designated areas

The closest OSV trail to the Granite Chief Wilderness boundary is 

the Mosquito Ridge marked, not groomed OSV trail, more than 

two miles to the west. 

OSV use is not allowed on the PCT. Groomed and marked OSV 

trails cross the PCT in four locations. OSV trails across the PCT 

in areas where OSV use is allowed are not designated.

Noise Size of areas (acres) potentially 

affected by noise;size of areas 

(acres) not designated for winter 

motorized use

638,002 acres designated for OSV use and potentially affected 

by noise.

198,271 acres not designated for OSV use and available for quiet 

recreation.

1,218 acres OSV use designated between January 1 and 

September 14. This area is available for quiet recreation from 

September through January

Air Quality Qualitative/narrative description of 

potential impacts (with reference 

to air quality analysis

Potential short-term impacts to the experience of recreational 

visitors in the vicinity of OSVs and grooming equipment due to 

the smell of exhaust emissions (see air quality report).

Scenery Qualitative/narrative description of 

potential visual impacts

Cross-country OSV use creates temporary tracks in the snow that 

crisscross the landscape. The visual evidence of snowmobile use 

decreases as fresh snow covers the tracks and/or when the snow 

melts at the end of the season.

Potential conflict with other 

resource values

Proximity of OSV use related to 

other resource values (such as 

tribal/ spiritual sites, sensitive 

wildlife areas, popular nonmotorized winter recreation areas, 

populated areas, neighboring 

Federal lands, etc.).

Existing conflict with historic structures at Robinson Flat.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

79

Resource Element Resource Indicator Measure

(Quantify if possible)

Existing Conditions

Designated Areas Wilderness Attributes Size of areas (acres) affected and 

duration of impact. Qualitative 

description for wilderness 

attributes

Opportunities for solitude may be temporarily affected due to the 

sights and sounds of OSVs near the wilderness boundaries. 

There are approximately 4,404 acres open to OSV use within 1/2 

mile of designated wilderness boundaries. The duration of the 

potential impacts would be short-term, during the winter while 

snow depth is adequate for OSVs to access the area.

Roadless Characteristics Size of area (acres) affected and 

duration of impact. Qualitative 

description for roadless 

characteristics

Approximately 109,234 IRA acres open to OSV use. Short term 

impacts to the roadless characteristics of: (1) undisturbed soil, 

water, and air (short-term impacts to air quality due to the 

presence of OSV exhaust), and (2) solitude (due to the sights 

and sounds of OSVs) during the winter while snow depth is 

adequate for OSVs to access the area.
Over-snow Vehicle Use Designation 

Tahoe National Forest

80

Cumulative Effects 

In alternative 1 both motorized and non-motorized winter use would continue to occur on trails and in 

areas across the forest, existing conflicts between these uses and desired experiences would continue in 

some popular areas. Cumulative impacts to the recreation experience are unlikely, since no changes 

would be made to the allowed uses or areas, and other ongoing or reasonably foresseable projects are not 

expected to impact winter recreation uses or create additional conflict between these uses. Short-term and 

temporary impacts to air quality (from OSV exhaust) and opportunities for solitude (due to OSV noise, 

and the presence of people) may occur when OSVs are present adjacent to Wilderness areas, within 

Inventoried Roadless Areas, or adjacent to the PCT. Noise from OSVs in areas and on trails across the 

forest would add to other sound sources, such as OSV grooming equipment, vehicles on highways, 

vehicles on Forest roads, equipment being used for forest management projects, etc.

Alternative 2 – Modified Proposed Action

Direct and Indirect Effects

Recreation Settings and Opportunities 

Alternative 2 would provide a range of winter motorized and non-motorized recreation opportunities 

across the Tahoe National Forest. Having a clearly designated system of trails and areas where OSV use 

is designated and the subsequent production of the OSV use map would improve information available to 

the public about opportunities for OSV use. This would assist both motorized and non-motorized 

recreationists in selecting areas that meet their setting and experience preferences, and therefore, would 

minimize the potential for conflict. 

Alternative 2 increases the total miles of OSV trail available for grooming and includes additional miles 

of OSV trail available for grooming on the Mosquito Ridge Trail in the Foresthill East OSV area. Actual 

groomed mileage varies and is based on snowfall and funding availability. 

The proposed crossing at the creek on the Howards Meadow loop would provide a connection to enhance 

loop-riding opportunities for OSVs in this area.

Alternative 2 designates fewer acres for OSV use compared to alternative 1 and 4, however, alternative 2 

focuses on providing motorized winter recreation opportunities in areas that receive high to moderate 

OSV use due to their access from parking and staging areas and groomed trails, elevation, and terrain 

while mitigating potential conflicts (particulary due to OSV noise and exhaust) in areas on the Forest that 

are also popular for non-motorized winter recreation activities. Alternative 2 provides a higher proportion 

of high-quality OSV use areas (defined by the high to moderate OSV use categories) relative to the acres 

designated for OSV use than alternatives 1 and 4, and about the same proportion as in alternative 5. Some 

popular areas for both backcountry skiiers and snowmobilers (e.g., Coon Canyon and the north and east 

bowls of Castle Peak) would remain designated for OSV use and therefore provide opportunities for both 

non-motorized and motorized winter recreation. These areas provide opportunites for winter visitors who 

enjoy using OSVs to reach backcountry areas to participate in non-motorized winter activities.

Alternative 2 reduces the total acres proposed to be designated for OSV use from the existing condition, 

and the designated OSV areas would be located generally above 5,000 feet elevation. This increases the 

acreage not designated for OSV use (compared to existing management (alternative 1), which would 

enhance quiet, non-motorized winter recreation opportunities, particularly in the lower elevations of the 

Forest. The specific areas that would not be designated for OSV use are included in portions of 18 of the 

19 OSV areas analyzed, and specifically a 1-acre area near Robinson Flat to protect historic structures, the 

High Loch Leven, Independence Lake, and Steephollow areas, and individual parcels of National Forest 

System lands currently under long-term special use permits for Royal Gorge Cross Country Ski Area, 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

81

Tahoe Donner Cross Country Ski Area, Boreal Ski Area, Donner Ski Ranch Ski Area, Sugar Bowl Ski 

Area, Alpine Meadows Ski Area and Squaw Valley Ski Area.

The proposed OSV use designations would be in compliance with existing ROS classes, maintaining a 

variety of both motorized and non-motorized recreation opportunities available across the national forest. 

Primitive and Semi-Primitive Non-Motorized areas would not be designated for OSV use (with the 

exception of the Grouse Management Area (041) and a small portion of the Sunflower Management Area 

(091) where public OSV use is allowed in the winter), while motorized opportunities would be available 

in Semi-Primitive Motorized, Roaded Natural and Rural settings. 

The forestwide requirement that cross-country travel is only allowed when there is adequate snow depth 

to avoid damage to resources, typically 12 inches, may impose additional limitations on OSV use, 

although it is likely that most OSV owners would not ride with less than adequate snow depths to prevent 

damage to their OSVs. Establishing the forestwide snow depth requirement for cross-country OSV use 

would minimize impacts to soil, water, vegetation, and wildlife resources, as described in the relevant 

sections of this analysis. The requirement that public OSV use on snow trails is only allowed when there 

is adequate snow depth to avoid damage to resources, typically 6 inches would allow access to higher 

elevations and deeper snow conditions on and off trails.

Conflicts between Motorized and Non-motorized Winter Experiences 

Based on 22,410 OSV visits per winter season, if use were spread evenly across each day of the season, 

there would be approximately 213 OSVs on the forest per day. Daily use may be higher during weekends 

and holidays and lower during the week. For the alternative 2, this equates to 1,910 acres and 1.1 miles of 

groomed trail per OSV. Based on the OSV use assumption that most OSV use would be concentrated 

along groomed trails, the trail opportunites in alternative 2 would be essentially the same as in existing 

conditions. The change from the existing 2,995 acres per OSV to 1,910 acres per OSV would not be 

likely to create use conflict, and there is still likely adequate acreage to disperse the use and avoid use 

conflict.

Motorized use has inherent conflicts with non-motorized recreationists who are typically seeking a quiet 

recreation setting that is not influenced by the sight, sound, or exhaust smell of motorized vehicles. There 

are also inherent conflicts in that motorized OSVs travel much faster and farther than non-motorized 

recreationists. Public OSV use may impact the setting for non-motorized experiences by making tracks 

through the snow that often crisscross across the landscape, leaving visual evidence of motorized use. The 

tracks only remain on the landscape until they are covered by additional snowfall or until the snow melts, 

and do not cause long-term impacts to scenery or the underlying soils and vegetation (see additional 

analysis in the applicable resource sections of this analysis). OSV tracks can interfere with cross-country 

skiing by causing ruts in the trails, and since OSVs travel faster and farther than non-motorized 

recreationists, they often “consume” the fresh powder slopes, limiting opportunities for backcountry 

skiers who are seeking similar opportunities on snow covered slopes (Snowlands 2015). 

Non-motorized winter recreation enthusiasts may continue to be displaced in some areas by motorized 

OSV use. Displacement or conflict may occur where non-motoirzed recreationists are unable to access 

areas for desired quiet, non-motorized experiences away from the sights, sounds, and smells of motorized 

use withouttraveling long distances through motorized routes and areas, or traveling further than they are

physically able to traverse in a typical day. There are approximately 62,635 acres available for high 

quality, quiet, non-motorized winter activities and 28 miles of cross-country ski trails and 20.5 miles of 

the PCT within 5 miles of plowed trailheads. These areas are free from motorized use and are easily 

accessible by non-motorized visitors in a typical day trip. This is a 27,032-acre decrease from alternative 

1. There are a total of approximately 429,378 acres across the Tahoe National Forest available for quiet, 

non-motorized experiences, where OSV use is not designated. Alternative 2 provides more quiet non-
Over-snow Vehicle Use Designation 

Tahoe National Forest

82

motorized opportunities than alternatives 1 and 4, resulting in fewer conflicts between motorized and nonmotorized uses, compared to the existing conditions, but fewer quiet non-motorized opportunities than in 

alternatives 3 and 5.

An approximate 10 percent increase in the miles of OSV trail available for grooming provides additional 

opportunities for motorized OSVs, and has the potential to increase OSV use and the associated possible 

conflicts as compared to the existing conditions. 

Two classes of OSV have been identified, including Class 1: over-snow vehicles 50 inches or less in 

width at the widest point on the vehicle, and Class 2: over-snow vehicles more than 50 inches in width at 

the widest point on the vehicle. There are currently no known conflicts occurring between different 

classes of OSV use. Snowcats are used for grooming OSV trails. The grooming operations are conducted 

during the night or during low-use timeframes, if possible, to avoid conflicts with day use. Since snowcats 

groom the OSV trails, the trails would be wide enough to accommodate larger tracked OSVs in addition 

to snowmobiles; however, there is currently very little use by larger tracked OSVs on the Tahoe National 

Forest. Class 1 OSVs are allowed on all designated OSV trails and areas. Class 2 OSVs are only allowed 

on designated OSV trails available for grooming. Only allowing the larger, class 2 OSVs on designated 

OSV trails available for grooming reduces the potential for conflict between different classes of OSVs. 

Monitoring of trailheads and groomed trail areas for user conflicts and public safety concerns would be 

implemented. If monitoring indicates that conflicts are occurring, the Tahoe National Forest would 

consider implementing site-specific controls as necessary (such as speed limits, segregated access points 

for motorized and non-motorized use, increased visitor information or increased on-site management 

presence). 

Designated Areas 

In alternative 2, the Mosquito Ridge OSV trail (along a section of Road 96 in the Foresthill East OSV 

area) would be groomed, rather than just a marked OSV trail. This would provide a groomed loop-riding

opportunity from the Robinson Flat area around French Meadows Reservoir. Grooming this section of 

trail could increase use as compared to existing conditions, however this use would not be expected to 

impact the Granite Chief Wilderness area, since the trail is located more than 2 miles to the west.

OSV use is designated on 74,875 acres within inventoried roadless areas, slightly fewer than in alternative 

1. Not designating OSV use in the High Loch Leven vicinity within the North Fork American River IRA 

reduces potential impacts on roadless characteristics, which include: (1) undisturbed or high quality soil, 

water and air and (2) opportunities for solitude in this area. Portions of the East Yuba, Lakes Basin, 

Grouse Lakes, Castle Peak, and Duncan Canyon Inventoried Roadless Areas would be designated for 

OSV use and are in areas where moderate to high OSV use occurs near the groomed trail system. 

Portions of five other inventoried roadless areas also fall in areas that would be designated for OSV use; 

however, low to no OSV use is expected in these areas. OSV use is prohibited in the Granite Chief IRA, 

including the designated Wilderness acreage. 

Alternative 2 designates OSV use in areas adjacent to the PCT segments within the Northeast Yuba, 

Sierraville West, Truckee, and Barker OSV analysis areas. Alternative 2 does not designate any areas for 

OSV use adjacent to the PCT segments within the Donner Summit, Summit West, and Granite Chief 

Wilderness OSV analysis areas. Alternative 2 designates 20 OSV trails across the PCT located in the 

Barker, Sierraville West and Yuba Northeast OSV analysis areas. Designating OSV trails acrossthe PCT 

would minimize the potential for motorized use to impact the trail experience and is consistent with the 

PCT comprehensive management plan. Limiting the locations where OSVs cross the trail would enhance 

the quiet, non-motorized experience while accommodating motorized access to OSV areas and 

maintaining OSV loop riding opportunities. Since most OSV trails acrossthe PCT would utilize roads 

identified on the Tahoe National Forest’s Motor Vehicle Use Map, motorized disturbance to the trail 

would be at a similar level as could be experienced in the summer months. Identifying designated trails on 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

83

the OSV use map would allow PCT visitors to know in advance where they may encounter OSVs 

crossing the trail, and alerts OSV riders to locations of potential non-motorized recreationists along the 

trail. This knowledge enhances both public safety and the experience expectations of visitors in these 

areas. Alternative 2 would minimize potential motorized OSV impacts to the non-motorized PCT 

experience to a greater extent than alternatives 1 and 4, but does not provide as much protection of the 

non-motorized PCT experience as in alternatives 3 and 5. The proposed areas to be designated, and not 

designated for OSV use along the PCT provide for multiple uses along the trail, while also giving 

consideration to the existence of the trail and users of the trail, consistent with the management direction 

for the PCT in the Tahoe Forest Plan. 

.
Over-snow Vehicle Use Designation 

Tahoe National Forest

84

Table 29. Recreation resource indicators and measures for alternative 2 direct and indirect effects

Resource Element Resource Indicator Measure

(Quantify if possible) Alternative 2, Modified Proposed Action

Motorized Recreation 

Opportunities – crosscountry

Opportunities for 

motorized winter uses

Quality of OSV 

opportunities

Size of areas (acres) 

designated for public OSV use, 

percent change from current 

management

Percent of designated acres 

that are considered high quality 

OSV opportunities based on the 

high to moderate OSV use 

assumption categories

406,895 acres designated for OSV use, 49 percent of the Tahoe 

NF. This is a 36 percent decrease from current management.

47 percent of acres designated for OSV use provide high quality 

OSV opportunities. This totals to approximately 191,311 acres.

OSV use is allowed when there is adequate snow depth to avoid 

damage to resources, typically a minimum of 12 inches

Motorized Recreation 

Opportunities –

designated snow 

trails and snow trails 

available for grooming

OSV trail designations Length (miles) of designated 

OSV trails available for 

grooming/Length (miles) of 

marked snow trails 

(ungroomed)

237 miles of designated National Forest System (NFS) OSV trails 

available for grooming

14 miles marked, ungroomed trails for OSV use

70 miles of designated OSV trails not available for grooming

OSV use on trails allowed when there is adequate snow depth to 

avoid damage to resources, typically a minimum of 6 inches

Non-motorized 

Recreation 

Opportunities -

displacement

Access to desired nonmotorized recreation 

settings and opportunities

Quality of non-motorized 

opportunities

Size of area (acres) and length 

of trails (miles) available to nonmotorized recreation 

enthusiasts within 5 miles of 

plowed trailheads

Percent of acres available for 

quiet, non-motorized use that 

are within desired areas 

(defined as areas within 5 miles 

of plowed trailheads)

62,635 acres and 28 miles of cross-country ski trails and 20.5 miles

of the PCT available for non-motorized recreation enthusiasts within 

5 miles of plowed trailheads

14.6 percent of the acres not designated for OSV use (available for 

quiet, non-motorized use) provide high quality non-motorized 

opportunities, within 5 miles of plowed trailheads. 

Non-motorized 

Recreation Conflicts –

Public Safety

Areas and trails available 

to non-motorized 

recreation enthusiasts for 

quality non-motorized 

recreation experiences

Size of areas (acres) not 

designated for OSV use, 

percent change from current 

management

429,378 acres not designated for OSV use

This is a 116 percent increase from current management

(alternative 1)
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

85

Resource Element Resource Indicator Measure

(Quantify if possible) Alternative 2, Modified Proposed Action

Non-motorized 

Recreation Conflicts –

Solitude, Air Quality, 

Scenery, Designated 

non-motorized areas

Proximity and frequency of 

OSV designations in 

relation to designated nonmotorized areas

Distance of groomed public 

OSV snow trails from 

designated areas, number of 

OSV trails across linear 

designated areas

The closest OSV trail to the Granite Chief Wilderness boundary is 

the. Mosquito Ridge marked (not groomed) OSV trail, more than 

two miles to the west.

OSV use is not allowed on the PCT. 

22 PCT crossings would be designated. 13 of which are on roads

(approximately 14 feet in width) and the other 9 are crossings of 

various widths (up to 0.25 miles wide), not on NFTS roads

Non-motorized 

Recreation Conflicts –

Solitude, Air Quality, 

Scenery, Designated 

non-motorized areas

(continued)

Soltude Size of areas (acres) that could 

be affected by noise/size of 

areas (acres) not designated for

winter motorized use

406,895 acres designated for OSV use and possibly affected by 

noise

429,378 acres not designated for OSV use and available for quiet 

recreation

Air Quality Qualitative/narrative description 

of possible impacts (with 

reference to air quality analysis)

Possible short-term impacts to the experience of recreational 

visitors in the vicinity of OSVs and grooming equipment due to the 

smell of exhaust emissions (see air quality report).

Scenery Qualitative/narrative description 

of possible visual impacts

Cross-country OSV use creates temporary tracks in the snow that 

crisscross the landscape. The visual evidence of snowmobile use 

decreases as fresh snow covers the tracks and/or when the snow 

melts at the end of the season.

OSV use areas are designated adjacent to the PCT in the 

Northeast Yuba, Sierraville West, Truckee, and Barker OSV areas, 

OSV use is not designated adjacent to the PCT in the Donner 

Summit, Summit West, and Granite Chief Wilderness areas.

Potential conflict with other 

resource values

Proximity of OSV use related to 

other resource values (such as 

tribal/ spiritual sites, sensitive 

wildlife areas, popular nonmotorized winter recreation 

areas, populated areas, 

neighboring Federal lands, 

etc.).

One acre is not designated for OSV use to protect historic 

structures.
Over-snow Vehicle Use Designation 

Tahoe National Forest

86

Resource Element Resource Indicator Measure

(Quantify if possible) Alternative 2, Modified Proposed Action

Designated Areas Wilderness Attributes Size of areas (acres) affected 

and duration of impact.

Qualitative description for 

wilderness attributes

Opportunities for solitude may be temporarily affected due to the 

sights and sounds of OSVs near the wilderness boundaries. There 

are approximately 2,305 acres designated for OSV use within 1/2 

mile of designated wilderness boundaries. The impacts would be 

short-term during the winter while snow depth is adequate for OSVs 

to access the area.

Roadless Characteristics Size of area (acres) affected 

and duration of impact. 

Qualitative description for 

roadless characteristics

Approximately 74,875 IRA acres designated for OSV use. Shortterm impacts to the roadless characteristics of (1) undisturbed soil, 

water, and (2) solitude during the winter while snow depth is 

adequate for OSVs to access the area. Fewer IRA acres that could 

be impacted by OSV use than in alternative 1.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

87

Cumulative Effects 

Recreation Settings and Opportunities 

The OSV route designations and restrictions increase the management presence across the Forest through 

additional signs, maps, and motorized route designations that visitors must understand and comply with, 

slightly impacting the managerial component of the forest setting. This could result in cumulative impacts 

when added to other ongoing and future national forest projects that place limitations or temporary 

restrictions on the recreating public, or that provide additional signs, maps, and motorized route 

designations that visitors must understand and comply with, such as the 2017 MVUM update. 

The trailhead and parking lot plowing activities associated with the OSV trail grooming program would 

also increase the presence of management personnel in the area; however, this would not be a change 

from existing conditions.

The foreseeable project, the Little Truckee Summit Parking Improvement project could cumulatively 

enhance winter recreational activities in this area.

Conflicts between Motorized and Non-motorized Winter Experiences 

Indirect impacts of noise from alternative 2 would be less than in alternative 1, based on the number of 

acres designated for OSV use, therefore the potential cumulative impacts to quiet recreation experiences 

when added to other forest management projects that could also generate noise, is less than in alternative 

1. One present action that could lead to cumulative noise impacts is the Placer County Water Agency 

(PCWA) gate and associated authorization to plow 15 miles of the Mosquito Ridge road, since OSVs, 

snow plows could be operating in the same area at the same time.

A general assumption can be made that as an area’s population increases over time, visitor use would also 

increase, along with the potential for use conflicts on the limited public recreation resources. However, 

OSV use is also dependent on weather conditions and snowpack. OSV use has not increased at the rate 

that was anticipated in the 2009 State EIR. Due to the fluctuations in OSV use levels and winter 

conditions, it is difficult to accurately predict whether use conflicts would continue to increase over time. 

As the climate changes and snow levels rise, the area on the Thaoe National Forest with sufficient snow 

for OSV use would be reduced. This would potentially lead to a loss of motorized recreation 

opportunities, or increased use conflicts as both motorized and non-motorized winter visitors are spread 

across an area with less snow and shorter winter seasons.

Designated Areas

OSV use is prohibited in designated areas on the Tahoe National Forest, such as Wilderness. There are no 

known potential cumulative impacts associated with the OSV prohibitions, which are in compliance with 

the relevant management direction for specific designated areas. Illegal encroachment by OSVs into nondesignated areas could occur, but would be monitored and dealt with as a law enforcement issue. The 

proposed Squaw Valley to Alpine Meadows Base-to-Base Gondola Project along a portion of the eastern 

Wilderness boundary, in addition to the OSV use designations in the Barker OSV area south of the 

Wilderness may add to the presence of people and OSVs that could be seen and heard from within the 

Wilderness during the winter months, temporaryily having a cumulative impact to opportunites for 

solitude within the Granite Chief Wilderness area, primarily near the eastern and southern Wilderness 

boundaries.
Over-snow Vehicle Use Designation 

Tahoe National Forest

88

Alternative 3

Direct and Indirect Effects

Recreation Settings and Opportunities

Alternative 3 would designate OSV use on fewer acres than any of the alternatives. With additional areas 

not designated for OSVs, the opportunities for winter non-motorized use (in areas not influenced by the 

sights, sounds and exhaust smells of OSV use) are enhanced, and opportunities for winter motorized use 

are reduced. Alternative 3 emphasizes providing greater non-motorized winter recreation opportunities 

compared to current management, however alternative 3 also designates existing popular OSV crosscountry areas and trails on the Forest for public OSV use. Alternative 3 provides the highest proportion of 

high-quality OSV use areas (defined by the high to moderate OSV use categories) relative to the acres 

designated for OSV of all Alternatives.

Groomed trail opportunities would be the same as under existing conditions.

Proposed OSV designations would be consistent with existing ROS classes, maintaining a variety of both 

motorized and non-motorized recreation opportunities available across the forest. Primitive and SemiPrimitive Non-Motorized areas would not to be designated for OSV use. In addition, the Grouse 

Management Area (041) would largely not be designated for OSV use. Winter motorized opportunities 

would be available in Semi-Primitive Motorized, Roaded Natural, and Rural settings. The additional areas 

not designated for OSV use, which are located primarily within the Semi-Primitive Motorized ROS class, 

would not require a change the existing ROS class, but would reduce the influence of motorized OSV use 

within these areas and help minimize impacts from motorized use on non-motorized winter visitors.

The forestwide snow depth requirement of 18 inches for both trail and cross-country travel would impose 

additional limitations on OSV use. Although it is likely that most OSV owners would not ride with less 

than adequate snow depths to prevent damage to their OSVs, the required depth of 18 inches may 

preclude access to some areas with lower snowfall, and may shorten the riding season due to lower snow 

depths both early and late in the season.

Conflicts between Motorized and Non-motorized Winter Experiences 

Alternative 3 would reduce acreage of areas designated for OSV use thereby enhancing opportunities for 

non-motorized experiences, and reducing the potential for conflict by providing greater separation of 

motorized and non-motorized uses compared to atlernatives 1, 2, and 4. 

Based on 22,410 OSV visits per winter season, if use were spread evenly across each day of the season, 

there would be approximately 213 OSVs on the forest per day. Daily use may be higher during weekends 

and holidays and lower during the week. For alternative 3, this equates to 1,296 acres and 1.3 miles of 

groomed trail per OSV. Based on the OSV use assumption that most OSV use would be concentrated 

along groomed trails, the trail opportunites in alternative 3 would be essentially the same as in existing 

conditions. The change from the existing 2,995 acres per OSV to 1,296 acres per OSV, although 

potentially noticeable to OSV visitors, would not be likely to create use conflict, and there is still likely 

adequate acreage to disperse the use and avoid use conflict.

Non-motorized winter recreation enthusiasts may continue to be displaced in some areas by motorized 

OSV use. Displacement or conflict may occur where non-motorized enthusiasts are unable to access areas 

for desired quiet, non-motorized experiences away from the sights, sounds, and smells of motorized use 

without traveling long distances through motorized routes and areas, or traveling further than they are 

physically able to traverse in a typical day. There are approximately 78,258 acres available for high 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

89

quality, quiet, non-motorized winter activities and 28 miles of cross-country ski trails and 20.5 miles of 

the PCT within 5 miles of plowed trailheads. These areas are free from motorized use and are easily 

accessible by non-motorized visitors in a typical day trip. This is an 11,409 acre decrease from alternative 

1. There are a total of approximately 560,301 acres across the Tahoe National Forest available for quiet, 

non-motorized experiences, where OSV use is not designated. There are also 1,408 acres designated for 

public cross-country OSV use in deer holding areas from January 1 through September 14, that are 

available for quiet recreation when OSVs are not present. Alternative 3 provides more quiet nonmotorized opportunities than any other alternative, resulting in fewer conflicts between motorized and 

non-motorized uses.

Class1 and class 2 OSVs would be allowed in all areas and on trails designated for OSV use, there are no 

known conflicts between classes of OSVs. Allowing the larger, class 2 OSVs on all designated OSV trails 

and areas poses a potential for conflict between different classes of OSVs, if the use of the larger Class 2 

OSV increases in the future. Based on current use levels, conflicts are not anticipated. Alternative 3 

effects on potential conflicts related to snow trails available for grooming and monitoring would be the 

same as described for alternative 2. 

Designated Areas 

The closest designated OSV trail to the wilderness boundary is the Mosquito Ridge. This marked (not 

groomed) OSV trail follows a portion of FS road 96 and is located more than two miles from the western 

boundary of the Granite Chief Wilderness Wilderness. This is the same as in the existing conditions, and 

no known wilderness incursions associated with this trail are anticipated. 

OSV use is designated on 45,272 acres within inventoried roadless areas, fewer than in alternatives 1, 2, 

or 4. The addition of areas not designated for OSV use, including the High Loch Leven area within the 

North Fork American River IRA and the PCT/Grubb, Devil’s Canyon, Coon Canyon, and Summit Lake 

areas within the Castle Peak IRA reduce potential impacts on roadless characteristics, which include 

undisturbed or high quality soil, water, and air, and opportunities for solitude in these areas. 

Alternative 3 generally does not designate any OSV use in areas directly adjacent to the PCT. In the 

Northeast Yuba and Sierraville West OSV analysis areas, the closest designated OSV areas are 

approximately 1⁄4 to 1⁄2 mile away from the PCT, the closest designated area to the PCT in the Donner 

Summit OSV area is approximately 1.5 miles away, and the closest designated area in the Truckee OSV 

area is approximately 3 miles away. No OSV use is designated in the Summit West, Granite Chief, or 

Barker OSV areas in alternative 3. Three OSV trails across the PCT would be designated over roads that 

are on the Tahoe National Forest Motor Vehicle Use Map, in the Sierraville West OSV analysis area. 

Fewer OSV trails across the PCT would be designated than in all other alternatives, further minimizing 

the potential for OSVs to impact the non-motorized trail experience and.wouldreduce OSV connectivity 

between designated areas on either side of the PCT. Alternative 3 minimizes impacts to the non-motorized 

PCT experience to a greater extent than alternatives 1, 2, and 4, and is similar to alternative 5.
Over-snow Vehicle Use Designation 

Tahoe National Forest

90

Table 30. Recreation resource indicators and measures for alternative 3 direct and indirect effects

Resource Element Resource Indicator Measure

(Quantify if possible) Alternative 3

Motorized Recreation 

Opportunities – crosscountry

Opportunities for 

motorized winter uses

Quality of OSV 

opportunities

Size of areas (acres) designated for 

public OSV use, percent change 

from current management

Percent of designated acres that are 

considered high quality OSV 

opportunities based on the high to 

moderate OSV use assumption 

categories

275,972 acres designated for OSV use, a 57 percent decrease 

from current management

58 percent of acres designated for OSV use provide high 

quality OSV opportunities. This totals to approximately 161,919

acres.

18-inch minimum snow depth for OSV use cross-country

Motorized Recreation 

Opportunities –

designated snow trails 

and snow trails 

available for grooming

OSV trail designations Length (miles) of designated OSV 

trails available for grooming/Length 

(miles) of marked snow trails 

(ungroomed)

217 miles of designated OSV trails available for grooming

38miles of marked, ungroomed trails for OSV use

25 miles of designated OSV trails not available for grooming

18-inch minimum snow depth for OSV use on trails

18-inch minimum snow depth for grooming 

Non-motorized 

Recreation 

Opportunities -

displacement

Access to desired nonmotorized recreation 

settings and 

opportunities

Quality of non-motorized 

opportunities

Size of area (acres) and length of 

trails (miles) available to nonmotorized recreation enthusiasts 

within 5 miles of plowed trailheads

Percent of acres available for quiet, 

non-motorized use that are within 

desired areas (defined as areas 

within 5 miles of plowed trailheads)

78,258 acres and 28 miles of cross-country ski trails and 20.5 

miles of the PCT available for non-motorized recreation 

enthusiasts within 5 miles of plowed trailheads

13.9 percent of the acres not designated for OSV use (available 

for quiet, non-motorized use) provide high quality nonmotorized opportunities, within 5 miles of plowed trailheads. 

Non-motorized 

Recreation Conflicts –

Public Safety

Areas and trails 

available to nonmotorized recreation 

enthusiasts for quality 

non-motorized 

recreation experiences

Size of areas (acres) not designate 

for OSV use

560,301 acres OSV use not designated, this is a 182 percent 

increase from current management

1,408 acres designated for public cross-country OSV use in 

deer holding areas from January 1 through September 14, 

available for quiet recreation when OSVs are not present)

Non-motorized 

Recreation Conflicts –

Solitude, Air Quality, 

Scenery, Designated 

non-motorized areas

Proximity and frequency 

of OSV designations in 

relation to designated 

non-motorized areas

Distance of groomed public OSV 

snow trails from designated areas, 

number of OSV trails across linear 

designated areas.

The closest OSV trail to the Granite Chief Wilderness boundary 

is the Mosquito Ridge marked (not groomed) OSV trail, more 

than two miles to the west.

OSV use is not allowed on the PCT and the Andesite Trail (3 

miles)

Three PCT crossings would be designated on NFTS roads.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

91

Resource Element Resource Indicator Measure

(Quantify if possible) Alternative 3

Non-motorized 

Recreation Conflicts –

Solitude, Air Quality, 

Scenery, Designated 

non-motorized areas

(continued)

Solitude Size of areas (acres) that could be

affected by noise/size of areas 

(acres) closed to winter motorized 

use

275,972 acres designated for OSV use and possibly affected by 

noise/560,301 acres not designated for OSV use and available 

for quiet recreation/1,408 acres designated for public crosscountry OSV use in deer holding areas from January 1 through 

September 14, available for quiet recreation when OSVs are 

not present

Air Quality Qualitative/narrative description of 

possible impacts (with reference to 

air quality analysis)

Short-term impacts that could affect the experience of 

recreational visitors in the vicinity of OSVs and grooming 

equipment due to the smell of exhaust emissions (see air 

quality report).

Scenery Qualitative/narrative description of 

possible visual impacts

Cross-country OSV use creates temporary tracks in the snow 

that crisscross the landscape. The visual evidence of 

snowmobile use decreases as fresh snow covers the tracks 

and/or when the snow melts at the end of the season.

OSV use is generally not designated adjacent to the PCT in 

Alternatives 3. In the Northeast Yuba and Sierraville West OSV 

analysis areas, the closest designated OSV areas are 

approximately 1⁄4 to 1⁄2 mile away from the PCT, the closest 

desingated area to the PCT in the Donner Summit OSV area is 

approximately 1.5 miles away, and the closest designated area 

in the Truckee OSV area is approximately 3 miles away. No 

OSV use is designated in the Summit West, Granite Chief, or 

Barker OSV areas

Potential conflict with 

other resource values

Proximity of OSV use related to 

other resource values (such as 

tribal/ spiritual sites, sensitive wildlife 

areas, popular non-motorized winter 

recreation areas, populated areas, 

neighboring Federal lands, etc.).

One acre is not designated for OSV use to protect historic 

structures.
Over-snow Vehicle Use Designation 

Tahoe National Forest

92

Resource Element Resource Indicator Measure

(Quantify if possible) Alternative 3

Designated Areas Wilderness Attributes Size of areas (acres) affected and 

duration of impact. Qualitative 

description for wilderness attributes

No areas are designated for OSV use within 1/2 mile of 

designated wilderness boundaries.

Roadless 

Characteristics

Size of area (acres) affected and 

duration of impact. Qualitative 

description for roadless 

characteristics

Approximately 45,272 IRA acres are designated for OSV use. 

Short-term impacts to the roadelss characteristics of 

undisturbed soil, water, and air (short-term impacts to air quality 

due to the presence of OSV exhaust), and solitude (due to the 

sights and sounds of OSVs) during the winter while snow depth 

is adequate for OSVs to access the area. Fewer IRA acres 

would be impacted by OSV use than in alternatives 1, 2 and 4.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

93

Cumulative Effects

The cumulative effects to recreation settings and opportunities from alternative 3 are similar to those 

described in alternative 2, with the following exceptions. 

The cumulative effects related to conflicts between motorized and non-motorized winter experiences 

would be less than described in alternative 2. The indirect impacts of noise from alternative 3 would be 

less than in all other alternatives, based on the number of acres designated for OSV use, therefore the 

potential cumulative impacts to quiet recreation experiences when added to other forest management 

projects or activities that could also generate noise, is less than in all other alternatives.

Cumulative effects related to winter use near the Granite Chief Wilderness boundaries would not occur in 

Alternative 3 since OSV use would not be designated in the Barker OSV area south of the Wilderness 

boundary.

Alternative 4

Direct and Indirect Effects 

Recreation Settings and Opportunities 

Alternative 4 would designate OSV use on the slightly more acres (641,105 acres) than in the existing 

conditions, alternative 1 (638,002 acres). Alternative 4 emphasizes providing opportunities for winter 

motorized recreation and designates more acres for OSV use than all other alternatives, however the 

proportion of designated acres that are considered high quality OSV use areas (defined by the high to 

moderate OSV use categories) relative to the acres designated for OSV use is lower than alternatives 2, 3, 

and 5, and the same as alternative 1. The minimum snow depth of 12 inches for cross-country OSV use 

and 6 inches for trails would allow motorized recreational access to higher elevations and adequate snow 

levels to a greater extent than Alternative 3 or 5, but with slightly less flexibility than described in the 

alternative 2 proposed snow depth requirements. 

Alternative 4 does not propose any additional areas that would not be designated for OSV use, other than 

those areas closed under existing conditions, and the miles of groomed snow trails would increase. 

The proposed OSV designations would comply with existing ROS classes, maintaining a variety of both 

motorized and non-motorized recreation opportunities available across the national forest. Primitive and 

Semi-Primitive Non-Motorized areas would not be designated for OSV use (with the exception of the 

Grouse Management Area (041) and a small portion of the Sunflower Management Area (091) where 

OSV use is allowed in the winter), while motorized opportunities would be available in Semi-Primitive 

Motorized, Roaded Natural and Rural settings. 

Conflicts between Motorized and Non-motorized Winter Experiences 

Alternative 4 would slightly increase the acreage of areas designated for OSV as compared to alternative 

1, thereby enhancing opportunities for motorized experiences. 

Based on 22,410 OSV visits per winter season, if use were spread evenly across each day of the season, 

there would be approximately 213 OSVs on the forest per day. Daily use may be higher during weekends 

and holidays and lower during the week. For alternative 4, this equates to 3,010 acres and 1.3 miles of 

groomed trail per OSV. Based on the OSV use assumption that most OSV use would be concentrated 

along groomed trails, the trail opportunites in alternative 4 would be slightly more per OSV than in all 

other alternatives. The change from the existing 2,995 acres per OSV to 3,010 acres per OSV, would 
Over-snow Vehicle Use Designation 

Tahoe National Forest

94

enhance opportunites for OSV use, but would not be likely to create use conflict, as there is adequate 

acreage to disperse the use and avoid use conflict.

Non-motorized winter recreation enthusiasts may continue to be displaced in some areas by motorized 

OSV use. Displacement or conflict may occur where non-motorized enthusiasts are unable to access areas 

for desired quiet, non-motorized experiences away from the sights, sounds, and smells of motorized use 

without traveling longdistances through motorized routes and areas, or traveling further than they are 

physically able to traverse in a typical day. There are approximately 22,310 acres available for high 

quality, quiet, non-motorized winter activities and 28 miles of cross-country ski trails and 20.5 miles of 

the PCT within 5 miles of plowed trailheads. These areas are free from motorized use and are easily 

accessible by non-motorized visitors in a typical day trip. This is a 67,357 acre reduction from the 

existing conditions, alternative 1, and is substantially lower than in all other alternatives. There are a total 

of 195,168 acres across the Tahoe National Forest available for quiet, non-motorized experiences, where 

OSV use is not designated. There are also 1,218 acres designated for public cross-country OSV use in 

deer holding areas from January 1 through September 14, available for quiet recreation when OSVs are 

not present. Alternative 4 provides slightly fewer non-motorized opportunities than alternative 1, and 

substantially fewer than in alternatives 2, 3, and 5, resulting in a higher potential for use conflicts in more 

areas of the forest.

A 20 percent increase in the miles of OSV trail available for grooming provides the most opportunities for 

motorized OSV trail use and has the potential to increase OSV use along the trail system, and the 

associated potential for conflicts as compared to the existing conditions. 

Class1 and class 2 OSVs would be allowed in all areas and on trails designated for OSV use, there are no 

known conflicts between classes of OSVs. Allowing the larger, class 2 OSVs on all designated OSV trails 

and areas poses a potential for conflict between different classes of OSVs, if the use of the larger Class 2 

OSV increases in the future. Based on current use levels, conflicts are not anticipated.

Designated Areas

In alternative 4, the Mosquito Ridge OSV trail (along a section of FS road 96) would be available for 

grooming, rather than just a marked OSV trail. This would provide a groomed loop riding opportunity 

from the Robinson Flat area around French Meadows Reservoir. Grooming this section of trail could 

slightly increase use as compared to existing conditions, however this use would not be expected to 

impact the Granite Chief Wilderness area, since the trail is located more than two miles to the west.

OSV use is designated on 112,388 acres within inventoried roadless areas, slightly more than in 

alternative 1. Potential impacts to roadless characteristics are the same as described in alternative 1.

Alternative 4 designates OSV use in areas adjacent to PCT segments within the Northeast Yuba, 

Sierraville West, Donner Summit (restricted use), Summit West, Truckee, and Barker OSV analysis areas. 

Alternative 4 does not designate any areas for OSV use adjacent to the PCT segments within the Granite 

Chief Wilderness OSV analysis area. Alternative 4 designates 21 OSV trails across the PCT located in the 

Barker, Sierraville West and Yuba Northeast OSV analysis areas. Potential impacts to the non-motorized 

trail experience along the PCT would be slightly more than in Alternative 2, and substantaially more than 

in alternatives 3 and 5.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

95

Table 31. Recreation resource indicators and measures for alternative 4 direct and indirect effects

Resource Element Resource Indicator Measure

(Quantify if possible) Alternative 4

Motorized Recreation 

Opportunities – crosscountry

Opportunities for 

motorized winter uses

Quality of OSV 

opportunities,

Size of areas (acres) designated for 

public OSV use, percent change from 

current management

Percent of designated acres that are 

considered high quality OSV 

opportunities based on the high to 

moderate OSV use assumption 

categories

641,105 acres designated for OSV use, a 0.5 percent increase 

from current management

33 percent of the acres designated for OSV use provide high 

quality OSV opportunities. This totals to approximately 

212,873 acres.

12-inch minimum snow depth for OSV use cross-country

Motorized Recreation 

Opportunities –

designated snow trails 

and snow trails 

available for grooming

OSV trail designations Length (miles) of designated OSV 

trails available for grooming/Length 

(miles) of marked snow trails 

(ungroomed)

259 miles of designated NFS OSV trails available for grooming

22 miles marked, ungroomed trails for OSV use

5 miles designated OSV trails not available for grooming

6-inch minimum snow depth for OSV use on trails

12-inch minimum snow depth for grooming 

Non-motorized 

Recreation 

Opportunities -

displacement

Access to desired nonmotorized recreation 

settings and 

opportunities

Quality of nonmotorized opportunities

Size of area (acres) and length of 

trails (miles) available to nonmotorized recreation enthusiasts 

within 5 miles of plowed trailheads

Percent of acres available for quiet, 

non-motorized use that are within 

desired areas (defined as areas 

within 5 miles of plowed trailheads)

22,310 acres and 28 miles of cross-country ski trails and 20.5 

miles of the PCT available for non-motorized recreation 

enthusiasts within 5 miles of plowed trailheads

11.4 percent of the acres not designated for OSV use 

(available for quiet, non-motorized use) provide high quality 

non-motorized opportunities, within 5 miles of plowed 

trailheads

Non-motorized 

Recreation Conflicts –

Public Safety

Areas and trails 

available to nonmotorized recreation 

enthusiasts for quality 

non-motorized 

recreation experiences

Size of areas (acres) not designated 

for OSV use

195,168 acres not designated for OSV use. This is a slight 

decrease from current management

1,218 acres designated for public cross-country OSV use in 

deer holding areas from January 1 through September 14, 

available for non-motorized recreation when OSVs are not 

present
Over-snow Vehicle Use Designation 

Tahoe National Forest

96

Resource Element Resource Indicator Measure

(Quantify if possible) Alternative 4

Non-motorized 

Recreation Conflicts –

Solitude, Air Quality, 

Scenery, Designated 

non-motorized areas

Proximity and frequency 

of OSV designations in 

relation to designated 

non-motorized areas

Distance of groomed public OSV 

snow trails from designated areas, 

number of OSV trails across linear 

designated areas

The closest OSV trail to the Granite Chief Wilderness 

boundary is the. Mosquito Ridge OSV trail, which is available 

for grooming under Alternative 4. The Mosquito Ridge Trail is 

more than two miles to the west.

OSV use is not allowed on the. 

14 PCT crossings on NFTS roads, 14 feet wide

7 PCT crossings not on roads would range in length from 0.15 

miles to 1.31 miles

Solitude Size of areas (acres) that could be

affected by noise/size of areas 

(acres) not designated to winter 

motorized use

641,105 acres designated for OSV use and possibly affected 

by noise /195,168 acres not designated for OSV use and 

available for quiet recreation/1,218 acres designated for public 

cross-country OSV use in deer holding areas from January 1 

through September 14, available for quiet recreation when 

OSVs are not present

Air Quality Qualitative/narrative description of 

possible impacts (with reference to air 

quality analysis)

Short-term impacts that could affect the experience of 

recreational visitors in the vicinity of OSVs and grooming 

equipment due to the smell of exhaust emissions (see air 

quality report).

Scenery Qualitative/narrative description of 

possible visual impacts

Cross-country OSV use creates temporary tracks in the snow 

that crisscross the landscape. The visual evidence of 

snowmobile use decreases as fresh snow covers the tracks 

and/or when the snow melts at the end of the season.

Alternative 4 designates OSV use in areas adjacent to PCT 

segments within the Northeast Yuba, Sierraville West, Donner 

Summit (restricted use), Summit West, Truckee, and Barker 

OSV analysis areas. Alternative 4 does not designate any 

areas for OSV use adjacent to the PCT segments within the 

Granite Chief Wilderness OSV analysis area

Potential conflict with 

other resource values

Proximity of OSV use related to other 

resource values (such as tribal/ 

spiritual sites, sensitive wildlife areas, 

popular non-motorized winter 

recreation areas, populated areas, 

neighboring Federal lands, etc.).

Existing conflict with historic structures at Robinson Flat. One 

acre not designated for OSV use to protect historic structures.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

97

Resource Element Resource Indicator Measure

(Quantify if possible) Alternative 4

Designated Areas Wilderness Attributes Size of areas (acres) affected and 

duration of impact. Qualitative 

description for wilderness attributes

Opportunities for solitude may be temporarily affected due to 

the sights and sounds of OSVs near the wilderness 

boundaries. There are approximately 5,235 acres designated 

for OSV use within 1/2 mile of designated wilderness 

boundaries, The duration of the possible impacts would be 

short-term, during the winter while snow depth is adequate for 

OSVs to access the area.

Roadless 

Characteristics

Size of area (acres) affected and 

duration of impact. Qualitative 

description for roadless 

characteristics

Approximately 112,388 IRA acres designated for OSV use. 

Short-term impacts to the roadless characteristics of (1) 

undisturbed soil, water, and air (short-term impacts to air 

quality due to the presence of OSV exhaust), and (2) solitude 

(due to the sights and sounds of OSVs) during the winter while 

snow depth is adequate for OSVs to access the area. Slightly 

more IRA acres could be impacted by OSVs than in alternative 

1 (current management).
Over-snow Vehicle Use Designation 

Tahoe National Forest

98

Cumulative Effects 

The cumulative effects to recreation settings and opportunities from Alternative 4 are similar to those 

described in alternative 2.

The cumulative effects related to conflicts between motorized and non-motorized winter experiences 

would be less than described in alternative 2. Indirect impacts of noise from alternative 4 would be 

slightly more than in alternative 1 and substantially more than alternatives 2, 3, and 5, based on the 

number of acres designated for OSV use, therefore the potential cumulative impacts to quiet recreation 

experiences when added to other forest management projects and activities that could also generate noise, 

is more than in all other Alternatives.

Cumulative effects related to winter use near the Granite Chief Wilderness boundaries would occur, as 

describe in alternative 2, since the Barker OSV area south of the Wilderness would be designated for OSV 

use.

Alternative 5

Direct and Indirect Effects

Recreation Settings and Opportunities 

In alternative 5, acres designated for cross-country OSV use would be slightly more than in alternative 3, 

but less than all other alternatives. Alternative 5 provides fewer opportunities for motorized winter 

recreation experiences on the Forest to emphasize protection of wildlife and other forest resources. 

Alternative 5 provides a higher proportion of high-quality OSV use areas (defined by the high to 

moderate OSV use categories) relative to the acres designated for OSV use than alternatives 1 and 4, and 

about the same proportion as in alternative 2. In addition, alternative 5 would provide greater 

opportunities for non-motorized winter recreation activities compared to alternatives 1, 2, and 4. Groomed 

trails mileage would be slightly less than in the existing conditions, and in alternative 3. This would 

reduce opportunities for motorized winter recreation compared to alternatives 1, 2, and 4, and would 

enhance opportunities for quiet, non-motorized activities across the forest. 

Changing Howard’s Loop to an out and back ride would eliminate a loop-riding opportunity, but also 

would protect the underlying resources soil and vegetation by closing the segment of trail that is not on an 

underlying road or trail. 

Not designating the marked Andesite Ridge trail would enhance quiet, non-motorized opportunities in the 

Andesite Ridge/Castle peak area.

Additional areas not designated for OSV use under alternative 5 include isolated parcels on 

Schallenberger Ridge adjacent to the state park (these parcels are also not designated for OSV use under 

alternatives 2 and 3), White Rock Lake, North and west sides of Mt. Lola, South flank of Sand Ridge, 

Grouse Ridge Area (which is also not designated for OSV use under alternative 3), Inventoried Roadless 

areas, Primitive and semi-primitive non-motorized areas, and Prosser-Boca. Not designating these areas 

would further enhance opportunities for quiet, non-motorized use and reduce conflicts between motorized 

and non-motorized winter use across the Forest. 

The proposed OSV designations would comply with existing ROS classes, maintaining a variety of both 

motorized and non-motorized recreation opportunities available across the national forest. Primitive and 

Semi-Primitive Non-Motorized areas would not be designated for OSV use (including the Grouse 

Management Area (041)), while motorized opportunities would be available in Semi-Primitive Motorized, 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

99

Roaded Natural and Rural settings. Not designating OSV use areas within the Semi-Primitive Motorized 

ROS class would not formally change the ROS class, but would reduce the influence of motorized OSV 

use within these areas and help minimize impacts to non-motorized winter visitors desiring a quiet 

recreation experience.

Requiring a minimum of 24 inches for OSV cross-country use and trail use could lead to a notable 

reduction in OSV opportunities during seasons, or portions of seasons with lower snowfall and in lower 

elevation areas of the Forest. This reduction of OSV opportunities could increase over time as changing 

climatic conditions impacted snow conditions.

Conflicts between Motorized and Non-motorized Winter Experiences 

Alternative 5 would reduce acreage of areas designated for OSV, as compared to all alternatives, except 

alternative 3, thereby enhancing opportunities for non-motorized experiences, and reducing the potential 

for conflict by providing greater separation of motorized and non-motorized uses compared to the 

alternatives 1, 2, and 4.

Based on 22,410 OSV visits per winter season, if use were spread evenly across each day of the season, 

there would be approximately 213 OSVs on the forest per day. Daily use may be higher during weekends 

and holidays and lower during the week. For the alternative 5, this equates to 1,409 acres and 1.2 miles of 

groomed trail per OSV. Based on the OSV use assumption that most OSV use would be concentrated 

along groomed trails, the trail opportunites in alternative 5 would be essentially the same as in alternative 

1 and 3. The change from the existing 2,995 acres per OSV to 1,409 acres per OSV, although potentially 

noticeable to OSV visitors, would not be likely to create use conflict, and there is still likely adequate 

acreage to disperse the use and avoid use conflict.

Non-motorized winter recreation enthusiasts may continue to be displaced in some areas by motorized 

OSV use. Displacement or conflict may occur where non-motorized enthusiasts are unable to access areas 

for desired quiet, non-motorized experiences away from the sights, sounds, and smells of motorized use 

without traveling long distances through motorized routes and areas, or traveling further than they are 

physically able to traverse in a typical day. There are approximately 89,667 acres available for high 

quality quiet, non-motorized winter activities and 28 miles of cross-country ski trails and 20.5 miles of 

the PCT within 5 miles of plowed trailheads. These areas are free from motorized use and are easily 

accessible by non-motorized visitors in a typical day trip. This is the same as in existing condition, 

alternative 1. There are a total of 536,127 acres across the Tahoe National Forest available for quiet, nonmotorized experiences, where OSV use is not designated. Alternative 5 provides slightly fewer acres for 

quiet non-motorized opportunities as compared to alternative 3. Compared to alternatives 1, 2, and 4, 

alternative 5 substantially decreases the potential for conflicts between motorized and non-motorized use 

within the areas where OSV use is not designated.

Alternative 5 provides only slightly fewer miles of OSV trail available for grooming as in the existing 

conditions and alternative 3; and fewer than in alternatives 2 and 4. The potential for OSV trail related 

conflict would remain about the same as in existing conditions. 

In alternative 5, OSV use would be limited to to designated OSV trails within 1 mile of existing OSV 

trailheads. This would enhance opportunities for non-motorized, quiet recreation in close proximity to 

plowed trailheads. This would help to minimize conflict between motorized and non-motorized uses and 

improve the sense of public safety at shared trailheads by providing areas near trailheads where nonmotorized enthusiasts could recreate without the concern of encountering OSVs traveling cross-country at 

high speeds. 
Over-snow Vehicle Use Designation 

Tahoe National Forest

100

Two classes of OSV have been identified in alternative 5, including Class 1: over-snow vehicles 50 

inches or less in width at the widest point on the vehicle and Class 2: over-snow vehicles more than 50 

inches in width at the widest point on the vehicle. There are currently no known conflicts occurring 

between different classes of OSV use. Snowcats are used for grooming OSV trails. The grooming 

operations are conducted during the night or during low use timeframes if possible to avoid conflicts with 

day use. Since snowcats groom the OSV trails, the trails would be wide enough to accommodate larger 

tracked OSVs in addition to snowmobiles; however, there is currently very little use by larger tracked 

OSVs on the Tahoe National Forest. Class 1 OSVs are allowed on all designated OSV trails and areas. 

Class 2 OSVs are only allowed on designated OSV trails available for grooming. Only allowing the 

larger, class 2 OSVs on designated OSV trails available for grooming reduces the potential for conflict 

between different classes of OSVs

Designated Areas

The OSV trail closest to the Granite Chief Wilderness boundary is the Mosquito Ridge marked (not 

groomed) OSV trail, along a portion of NFS road 96, located more than 2 miles to the west. This is the 

same as in the existing conditions, and no known wilderness incursions associated with this trail are 

anticipated.

OSV use would be designated on only 5,161 acres within inventoried roadless areas, fewer than all other 

alternatives. This would enhance roadless characteristics related to naturalness, and outstanding 

opportunities for solitude or primitive and unconfined recreation in a majority of inventoried roadless 

areas acres across the forest. There would be minimal impacts to roadless characteristics of undisturbed or 

high quality soil, water, air, and solitude because OSVs and their associated sights, sounds, and exhaust 

would not be present within a majority of IRA acres. Alternative 5 provides the most protection to 

roadless area characteristics when compared to all other alternatives. 

Ten OSV trails across the PCT would be designated on National Forest Transportation (NFTS) roads 

displayed on the Motor Vehicle Use Map (MVUM). Alternative 5 is more restrictive on where OSV trails 

are designated across the PCT when compared to alternatives 1, 2, and 4, but not as restrictive as 

alternative 3. 

Alternative 5 would not designate OSV use adjacent to the PCT up to one-half mile in the visible lands on 

each side of the Pacific Crest National Scenic Trail or smaller as the visible landscape along the Trail 

would be smaller than one-half mile on each side of the trail due to topography (in the Northeast Yuba, 

Sierraville West, Donner Summit, Truckee and Barker OSV analysis areas). Alternative 5 does not 

designate any OSV use areas in the Summit West and Granite Chief Wilderness OSV Analysis areas. This 

would protect the trail experience for PCT visitors and would eliminate the potential for OSV use to 

impact the trail experience (other than on theat 10 designated OSV trails across the PCT) and reduce the 

potential for conflict between motorized and non-motorized uses. Alternative 5 would minimize potential 

impacts from OSVs on the non-motorized trail experience to a similar extent as in alternative 3, and 

substantially more than in alternatives 1, 2, and 4.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

101

Table 32. Recreation resource indicators and measures for alternative 5 direct and indirect effects

Resource Element Resource Indicator Measure

(Quantify if possible) Alternative 5

Motorized Recreation 

Opportunities –

cross-country

Opportunities for 

motorized winter uses

Quality of OSV 

opportunities

Size of areas (acres) designated for public OSV 

use, percent change from current management

Percent of designated acres that are 

considered high quality OSV opportunities 

based on the high to moderate OSV use 

assumption categories

300,146 acres designated for OSV use, a 53 percent 

decrease from current management

48 percent of the designated acres provide high quality 

OSV opportunities. This totals to approximately 145,420

acres.

24-inch minimum snow depth for OSV use crosscountry

Motorized Recreation 

Opportunities –

designated snow 

trails and snow trails 

available for 

grooming

OSV trail designations Length (miles) of designated OSV trails 

available for grooming/Length (miles) of 

marked snow trails (ungroomed)

215 miles of designated NFS OSV trails available for 

grooming/25 miles marked snow trails (ungroomed)

24-inch minimum snow depth for OSV use on trails

17 miles designated OSV trails not available for 

grooming 

24 inch minimum snow depth for OSV use on trails

12 inch minimum snow depth for grooming

Non-motorized 

Recreation 

Opportunities -

displacement

Access to desired nonmotorized recreation 

settings and 

opportunities

Quality of nonmotorized opportunities

Size of area (acres) and length of trails (miles) 

available to non-motorized recreation 

enthusiasts within 5 miles of plowed trailheads

Percent of acres available for quiet, nonmotorized use that are within desired areas 

(defined as areas within 5 miles of plowed 

trailheads)

89,667 acres and 28 miles of cross-country ski trails

and 20.5 miles of the PCT available for non-motorized 

recreation enthusiasts within 5 miles of plowed trailhead

16.7 percent of the acres not designated for OSV use 

(available for quiet, non-motorized use) provide high 

quality non-motorized opportunities, within 5 miles of 

plowed trailheads.

Non-motorized 

Recreation Conflicts 

– Public Safety

Areas and trails 

available to nonmotorized recreation 

enthusiasts for quality 

non-motorized 

recreation experiences

Size of areas (acres) not designated for OSV 

use

536,127 acres not designated for OSV use
Over-snow Vehicle Use Designation 

Tahoe National Forest

102

Resource Element Resource Indicator Measure

(Quantify if possible) Alternative 5

Non-motorized 

Recreation Conflicts 

– Solitude, Air 

Quality, Scenery, 

Designated nonmotorized areas

Proximity and frequency 

of OSV designations in 

relation to designated 

non-motorized areas

Distance of groomed public OSV snow trails 

from designated areas, number of OSV trails 

across linear designated areas

The closest OSV trail to the Granite Chief Wilderness 

boundary is the. Mosquito Ridge marked (not groomed) 

OSV trail, more than 2 miles to the west.

OSV use is not allowed on the PCT. 

10 PCT crossings would be designated. 

A non-motorized corridor up to one-half mile in the 

visible lands on each side of the PCT will be 

established.

Solitude Size of areas (acres) that could be affected by 

noise/size of areas (acres) would not be 

designated to winter motorized use

300,146 acres designated for OSV use and possibly

affected by noise

536,127 acres not designated for OSV use and 

available for quiet recreation

Air Quality Qualitative/narrative description of possible 

impacts (with reference to air quality analysis)

Short-term impacts that could affect the experience of 

recreational visitors in the vicinity of OSVs and 

grooming equipment due to the smell of exhaust 

emissions (see air quality report).

Scenery Qualitative/narrative description of possible 

visual impacts

Cross-country OSV use creates temporary tracks in the 

snow that crisscross the landscape. The visual 

evidence of snowmobile use decreases as fresh snow 

covers the tracks and/or when the snow melts at the 

end of the season.

Alternative 5 would not designate OSV use adjacent to 

the PCT up to one-half mile in the visible lands on each 

side of the Pacific Crest National Scenic Trail or smaller 

as the visible landscape along the Trail would be 

smaller than one-half mile on each side of the trail due 

to topography (in the Northeast Yuba, Sierraville West, 

Donner Summit, Truckee and Barker OSV analysis 

areas). Alternative 5 does not designate any OSV use 

areas in the Summit West and Granite Chief 

Wilderness OSV Analysis areas.

Potential conflict with 

other resource values

Proximity of OSV use related to other resource 

values (such as tribal/ spiritual sites, sensitive 

wildlife areas, popular non-motorized winter 

recreation areas, populated areas, neighboring 

Federal lands, etc.).

Existing conflict with historic structures at Robinson 

Flat. One acre is not designated for OSV use to protect 

historic structures.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

103

Resource Element Resource Indicator Measure

(Quantify if possible) Alternative 5

Designated Areas Wilderness Attributes Size of areas (acres) affected and duration of 

impact. Qualitative description for wilderness 

attributes

Opportunities for solitude may be temporarily affected 

due to the sights and sounds of OSVs near the 

wilderness boundaries, although to a lesser degree 

than in alternatives 1 through 4. There are 

approximately 2,125 acres designated for OSV use 

within 1/2 mile of designated wilderness boundaries. 

The duration of the potential impacts would be shortterm, during the winter while snow depth is adequate 

for OSVs to access the area.

Roadless 

Characteristics

Size of area (acres) affected and duration of 

impact. Qualitative description for roadless 

characteristics

Approximately 5,161 IRA acres would be designated for

OSV use. Short-term impacts to (1) undisturbed or high 

quality soil, water, and air (short-term impacts to air 

quality due to presence of OSV exhaust), and (2) 

solitude (due to the sights and sounds of OSVs) during 

the winter, while snow depth is adequate for OSVs to 

access the area. Alternative 5 provides the most 

protection for roadless area characteristics when 

compared to all other alternatives.
Over-snow Vehicle Use Designation 

Tahoe National Forest

104

Cumulative Effects 

The cumulative effects to recreation settings and opportunities from Alternative 5 are similar to those 

described in alternative 2.

The cumulative effects related to conflicts between motorized and non-motorized winter experiences 

would be less than described in Alternative 2. The Indirect impacts of noise from Alternative 5 would be 

substantially less than in Alternatives 1, 2, and 4, and slightly more than in Alternative 3, based on the 

number of acres designated for OSV use, therefore the potential cumulative impacts to quiet recreation 

experiences when added to other forest management projects or activities that could also generate noise, 

is less than in Alternatives 1, 2, and 4, and slightly more than in Alternative 3.

Cumulative effects related to winter use near the Granite Chief Wilderness boundaries would occur in 

Alternative 5, but to a lesser degree than in Alternaive 2 or 4, since fewer acres would be designated for 

OSV use in the Barker OSV area, south of the Wilderness boundary.

Summary of Environmental Effects

Recreation Settings and Opportunities

Alternatives 2 and 4 increase the miles of snow trail available for grooming. Alternatives 3 and 5 maintain 

approximately the same amount of snow trail available for grooming as in the existing conditions. Crosscountry travel by OSV is limited by minimum snow depth requirements for all action alternatives; 

however, alternative 2 provides the most flexibility in application of the minimum snow depth by 

requiring only adequate snow depth to avoid damage to resources. Alternative 5 represents the most 

restrictive snow depth requirement of 24 inches for both cross-country travel and travel on OSV trails. 

Alternatives 2 and 4 provide the most access for motorized OSV use, alternative 3 enhances opportunities 

for quiet, non-motorized recreation with substantially more acreage where OSV use would not be 

designated. Overall, alternatives 3 and 5 provide the most non-motorized winter recreation opportunities. 

For this analysis, OSV opportunites across the Tahoe National Forest were mapped based on the OSV use 

assumptions criteria (listed in the Methodology section above). The areas that fall within the high to 

moderate OSV use areas are considered to provide high quality OSV opportunities based on the proximity 

to groomed trails and plowed trailheads, open meadows with trail access, and slopes with open vegetation 

near groomed trails. Alternative 3 provides the highest proportion of high-quality OSV use areas relative 

to the acres designated for OSV use in this alternative, as defined by the high to moderate OSV use 

assumption categories. Alternatives 2 and 5 provide approximately the same percentage of high quality 

OSV use areas as a proportion of designated OSV use areas, and alternative 4 provides about the same 

percentage of high quality OSV use areas as alternative 1, existing conditions.

Of the acres not designated for OSV use, and available for quiet, non-motorized recreation, alternatives 

5 provides the highest percentage of high-quality, desirable, non-motorized opportunities as defined as 

areas within 5 miles of plowed trailheads. Alternative 2 provides more acreage of desireable high-quality 

non-motorized opportunities near plowed trailheads than alternatives 3 and 4 but substantially greater 

acreage compared to alternatives 1 and 4. Alternative 4 provides fewer high quality, desireable, nonmotorized opportunities than all other alternatives.

Conflicts between Motorized and Non-motorized Uses

All action alternatives minimize conflicts between motorized and non-motorized uses to some degree by 

designating a clear system of OSV trails and Areas, and development of the subsequent OSV use maps 

that wouldl allow visitors to choose areas to recreate that would best meet their expectations and desired 

settings.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

105

Alternative 3 minimizes conflicts between motorized and non-motorized uses to a greater extent than 

proposed in alternatives 2 and 4, by designating additional areas where OSV use is not designated. 

Alternative 5 further minimizes conflicts by not designating areas for OSV use within a one-mile buffer 

around plowed trailheads, and maintains the quiet, non-motorized experience along the PCT by not 

designating OSV use adjacent to the PCT up to one-half mile in the visible lands on each side of the 

Pacific Crest National Scenic Trail or smaller as the visible landscape along the Trail would be smaller 

than one-half mile on each side of the trail due to topography. These designations provide separate areas 

for non-motorized recreation that are not influenced by the noise, smell of exhaust and presence of OSVs. 

Alternatives 1, 2, and 4 provide the most acres designated for public OSV use, and therefore have the 

potential for continued or increased conflict between motorized and non-motorized uses in the future. In 

all alternatives.

Alternative 2 substantially increases opportunities for quiet, non-motorized use while also moderately 

increasing OSV trail opportunities. Alternative 3 substantially increases opportunities for quiet nonmotorized use while maintaining the same level of OSV trail opportunities as in existing conditions. 

Alternative 4 provides approximately the same amount of quiet, non-motorized opportunities as in 

existing conditions, alternative 1, but substantially increases OSV trail opportunities. Alternative 5 

substantially increases opportunities for quiet, non-motorized use while maintaining approximately the 

same level of OSV trail opportunities as in existing conditions. 

Alternatives 2 and 5 minimize potential conflicts between different classes of OSVs by allowing the 

larger, class 2 OSVs only on OSV trails available for grooming.

Alternatives 1, 2 and 4 provide greater opportunities for motorized winter recreation, and therefore, have 

the potential for continued or increased conflict between motorized and non-motorized uses in the future.

Designated Areas

Potential impacts to designated wilderness from the OSV trail system are minimal, and the same in all 

alternatives, there are fewer acres designated for OSV use adjacent to wilderness in alternative 5 than in 

all other alternatives. Alternatives 3 and 5 provides additional protection of the roadless characteristics by 

designating OSV use in fewer Inventoried Roadless Area acres than the other alternatives. OSV use is 

also not designated along the Wild and Scenic North Fork of the American River. All of the action 

alternatives designate OSV trails across the PCT that would minimize the influence of motorized use on 

non-motorized opportunities and quiet settings along the trail. Alternative 5 further protects the PCT 

experience by not designating OSV use in areas within the USFS Scenery Management System definition 

of Foreground for the PCT.

Impacts of the Forest Plan Amendment

As stated in Chapter 2, the Responsible Official has determined the proposed plan amendment is directly 

related to 36 CFR 219.10 Multiple Use, (a)(1) recreation settings and opportunities. The health and resiliency of 

the Tahoe National Forest’s natural resources are critical to the sustained delivery of nature-based 

recreation settings and opportunities. As such, recreation settings and opportunities need to be 

compatible with the landscape’s ability to support associated types of activities, use levels, access, and 

infrastructure. Motorized recreation opportunity spectrum (ROS) classes are located on landscapes 

where the topography, geology, and soils can support motorized use and the associated roads and 

motorized trails. ROS provides a framework where recreational opportunities, activities and expected 

experiences are integrated to ensure compatibility with the landscape’s natural and cultural resource 
Over-snow Vehicle Use Designation 

Tahoe National Forest

106

values. The ROS establishes recreational settings particularly informative for decisions on infrastructure 

and the built environment but is not intended to be the sole framework for managing recreational uses 

and activities.

The Tahoe Land and Resource Management Plan (LRMP 1990) established public OSV use through 

standards and guidelines for each management area that were associated with ROS classifications. 

Management areas were open to OSV use or closed to OSV use or OSVs were restricted to designated 

routes only (DEIS, Volume 2, Appendix B). To modernize the Tahoe National Forest’s approach, the 

Responsible Official has proposed to adopt a forest-wide standard to “manage over the snow vehicle 

(OSV) use through designation of routes and trails consistent with travel management regulations,” which 

would replace the LRMP’s 1990 standards and guidelines. Such an approach would continue to require 

project-level OSV use designation decisions to be consistent with management direction in the LRMP, as 

amended, including ROS classifications. However, adhering to the Travel Management Rule’s 

designation criteria at 36 CFR 212.55, which requires a granular, site-specific approach to designating 

areas and trails for public OSV, enables the Forest Service to consider factors in addition to ROS that 

contribute to sustained delivery of nature-based recreation. In applying the Travel Management Rule’s 

criteria for designating OSV trails, and areas (36 CFR 212.55), the Forest Service would be proposing, 

analyzing, and making OSV use designations in a manner that was not contemplated or required when the 

LRMP was adopted in 1990. 

The proposed plan amendment would not change the existing LRMP’s ROS classifications. Rather, the 

forest plan amendment would appropriately place OSV use designations at the project-level, with each 

designation requiring site-specific planning, environmental analysis, and decision-making. Project-level 

planning and analysis would allow the Responsible Official to more rapidly and efficiently make 

changes to OSV use designations as needed to respond to changing conditions and/or new monitoring 

information. The proposed amendment would allow the Forest Service to more rapidly adapt sitespecific OSV use designations to new information and/or changed circumstances as a forest plan 

amendment would not be required to make changes in use designations.

Compliance with LRMP and Other Relevant Laws, Regulations, Policies 

and Plans 

Alternative 1, no action, would not comply with Subpart C of the Travel Management rule that requires 

designation of roads, trails, and areas on National Forest System lands to provide for over-snow vehicle 

use. 

Alternatives 2, 3, 4, and 5 would comply with Subpart C of the Travel Management rule. The Tahoe 

National Forest Land and Resource Management Plan would be amended under these alternatives to 

ensure the Subpart C Travel Management Rule designations would be consistent with the Forest Plan. 

Other Relevant Mandatory Disclosures

Short-term Uses and Long-term Productivity 

Short-term uses will not affect the long-term productivity of recreation resources.

Unavoidable Adverse Effects 

Allowing motorized OSV use, which is an acceptable use of National Forest System lands, unavoidably 

affects non-motorized or quiet opportunities in some areas, as discussed in the analysis related to conflicts 

between motorized and non-motorized winter experiences. 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

107

Irreversible and Irretrievable Commitments of Resources

OSV trail and area designations are not irreversible and irretrievable commitments of resources. 

Noise

Relevant Laws, Regulations, and Policy

Regulatory Framework

National Forest Management Act

Specifically for off-highway vehicle management, the National Forest Management Act requires that this 

use be planned and implemented to protect land and other resources, promote public safety, and minimize 

conflicts with other uses of the National Forest System lands. The National Forest Management Act also 

requires that a broad spectrum of forest and rangeland-related outdoor recreation opportunities be 

provided that respond to current and anticipated user demands. 

Sierra Nevada Forest Plan Amendment

The Sierra Nevada Forest Plan Amendment established standards and guidelines specific to wheeled 

motor vehicle travel off of designated routes, trails, and limited OHV use areas. Unless otherwise 

restricted by current forest plans or other specific area standards and guidelines or Forest Orders, crosscountry travel by OSVs would continue, Forestwide Standard and Guideline number 69 (USDA Forest 

Service 2009b).

Land and Resource Management Plan

The Tahoe National Forest Land and Resource Management Plan (LRMP 1990) as amended provides 

forestwide and management area-specific goals and strategies, desired future conditions, land allocation, 

and standards and guidelines relevant to this noise analysis as follows: 

Management Goals and Strategies:

Recreation:

Recognize the value of semi-primitive motorized (SPM) and non-motorized (SPNM) areas in the forest

because of their scarcity and the demand for the few acres remaining. Closely monitor the loss of 

inventoried SPNM and SPM land that is not allocated in the Plan for these ROS classes. Where possible, 

avoid losing SPM and SPNM areas during the planning period by considering options that would not road 

the areas significantly.

Wilderness

Manage the Granite Chief Wilderness area to preserve the wilderness character of its living and nonliving 

components and to provide for compatible human use and enjoyment.

Provide quality wilderness experiences for the public.
Over-snow Vehicle Use Designation 

Tahoe National Forest

108

Management Standards and Guidelines

OSV Use

The Tahoe National Forest LRMP uses standards and guidelines to establish OSV use designations across 

the Tahoe National Forest. Each of the Forest’s 109 management areas has a standards and guidelines that 

specifies whether: (1) the management area is open to OSV travel (for example, the Lavezzola 

Management Area, LRMP, pg. V-95) or (2) closed to OSV travel (for example, the Coolbrith 

Management Area, LRMP, pg. V-85) or (3) OSVs are restricted to designated routes (for example, the 

Queens Management Area, LRMP, pg. V-339). Some of the Forest’s management areas have a standard 

and guideline that closes a portion of the management area to OSVs, sometimes during a particular season 

(for example, the Pendola Management Area, LRMP, pg. V-174). Appendix B displays the Tahoe 

National Forest LRMP OSV use standards and guidelines for each of the Forest Plan’s 109 management 

area.

Recreation Opportunity Spectrum

The Tahoe National Forest LRMP uses forestwide standards and guidelines to define the following 

Recreation Opportunity Spectrum classes: Primitive (P), Semi Primitive Non-Motorized (SPNM), Semi 

Primitive Motorized (SPM), Roaded Natural (RN), Rural (R), and Modern Urban (MU) (LRMP, 

Forestwide Standards and Guidelines #8 through #13, pp. V-20 through V-22). Each of the Forest Plan’s 

109 management areas is assigned an ROS class (TNF LRMP, pp. V-69 through V-544).

Pacific Crest National Scenic Trail

The Tahoe National Forest LRMP applies the following management area-specific standard and guideline 

to the 13 management areas through which the Pacific Crest National Scenic Trail (PCT) traverses: “The 

standards and guidelines for location, design, signing, user facilities, and management of the PCNST will 

be in accordance with the criteria established in the PCNST Comprehensive Plan, 1/18/82” (LRMP, pg. 

V- 64).

The 1982 Comprehensive Plan provides the following direction for winter use along the Pacific Crest 

National Scenic Trail:

Winter use (cross-country skiing and snowshoeing) should be accommodated where practical and 

feasible. Each agency should follow its own procedures for marking and signing the trail for winter 

use purposes. As a guideline, all trail markers should be at eye level (approximately 40” above 

average maximum snow depth). Sanitation facilities and snow removal for parking may be 

necessary. Any improvements, or alterations of the vegetation, should not detract from the quality of 

the recreation opportunities for other trail activities such as hiking and horseback riding.

Snowmobiling along the trail is prohibited by the National Trails System Act, P.L. 90-543, Section 

7(c). Winter sports plans for areas through which the trail passes should consider this prohibition in 

determining areas appropriate for snowmobile use. Winter sports brochures should indicate 

designated snowmobile crossings on the Pacific Crest Trail where it is signed and marked for winter 

use. If cross-country skiing and/or snowshoeing is planned for the trail, any motorized use of 

adjacent land should be zoned to mitigate the noise of conflict.

Federal Law

The proposed OSV designations will be reviewed to determine their consistency with the following 

applicable laws, regulations and policies:

• Wilderness Act of 1964 and applicable Wilderness Implementation Plans
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

109

• National Trails System Act of 1968 (P.L. 90-543) and the Pacific Crest National Scenic Trail 

Comprehensive Plan

• 2005 Travel Management Rule – Subpart C (36 CFR Parts 212 and 261) as amended in 2015 - Use by 

Over-snow Vehicles (Travel Management Rule)

Executive Orders

Executive Order 11644 of February 8, 1972, as amended by Executive Order 11989 of May 24, 1977, and 

by Executive Order 12608 of September 9, 1987, requires certain Federal agencies, including the Forest 

Service, to “ensure that the use of off-road vehicles on public lands [is] 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.”

State and Local Law

California Vehicle Code (CVC) Section 27200 – regulates noise emitted by vehicles.

CVC Section 27203 limits noise at 82 dBA for snowmobiles manufactured after 1972. Noise levels 

generated by OSVs are further limited through manufacturer restrictions. Snowmobiles produced since 

February 1, 1975, and certified by the Snowmobile Safety and Certification Committee’s independent 

testing company emit no more than 78 dBA from a distance of 50 feet while traveling at full throttle when 

tested under the Society of Automotive Engineers (SAE) J192 procedures. Additionally, those produced 

after June 30, 1976, and certified by the Snowmobile Safety and Certification Committee’s independent 

testing company emit no more than 73 dBA at 50 feet while traveling at 15 mph when tested under SAE 

J1161 procedures (California Department of Parks and Recreation 2010).

OSV use on county roads and National Forest System lands are subject to the State standards described 

above. The Tahoe LRMP does not identify Standards and Guidelines regulating noise emissions of forest 

activities (California Department of Parks and Recreation 2010).

Methodology 

This analysis uses SPreAD-GIS: an ArcGIS toolbox for modeling the propagation of engine noise in a 

wildland setting Version 2.0. SPreAD-GIS is based on the System for the Prediction of Acoustic 

Detection, a model developed by the Forest Service and Environmental Protection Agency to predict and 

plan for recreation opportunities in national forests. Input data includes commonly available datasets 

including:

• Digital elevation model (DEM)

• Land cover

• Local weather conditions (average air temp, relative humidity, wild speed and direction for given 

season)

• Sound source characteristics (from a table of built in source types)

• Ambient sound conditions (a tool is available to estimate this based on land cover and a table of 

background sound for various environmental conditions)

Resource Indicators and Measures 

Resource indicators and measures shown in table 19 will be used to measure and disclose effects to noise

related to OSV use designations and grooming trails for OSV use.
Over-snow Vehicle Use Designation 

Tahoe National Forest

110

Table 33. Resource indicators and measures for alternative 2 direct and indirect effects

Resource 

Element

Resource Indicator Measure

(Quantify if possible)

Noise Opportunities for 

motorized winter 

uses

Size of areas (acres) open to public, cross-country OSV use; 

percentage change compared to current management.

Acres and percent of designated acres that are anticipated to have high 

to moderate OSV use levels and the associated potential for noise 

impacts.

OSV designations Length of snow trails (miles), groomed and ungroomed, designated and 

identified for public OSV use

Spatial and Temporal Context for Effects Analysis

Spatial Context:

The spatial boundaries for analyzing the direct and indirect effects to noise are within the Tahoe National 

Forest boundary, because the proposed OSV designation decision would apply to OSV trails and areas 

within the forest boundary. 

The spatial boundaries for analyzing cumulative effects to noise are within the Tahoe National Forest 

boundary, because the OSV designations would apply to OSV trails and areas within the forest boundary 

and have the potential to cumulatively impact OSV recreation experiences and opportunities across the 

forest.

Effects Timeframe:

The temporal boundaries for analyzing the direct and indirect effects to noise are, in the short term, one 

year and in the long term up to 20 years. Short-term effects such as changes in the acres that could be

impacted by OSV noise would occur upon implementation of the OSV designation decision. Long-term 

effects such as decreases in user conflicts due to effective management of OSV use through a designated 

OSV system of trails and areas would occur over the life of the decision. 

The temporal boundaries for analyzing cumulative effects to noise are up to 20 years, because the OSV 

designations would remain in effect over the long term, and would therefore, overlap in time with other 

forest management activities with potential to cumulatively impact OSV recreation experiences and 

opportunities.

Affected Environment 

Noise

The sounds associated with OSV use and the ancillary activities of operating plowing and grooming 

equipment associated with the winter OSV activities may be interpreted as noise with possible impacts to 

other recreational uses, and wildlife resources. These effects are specifically addressed in the Recreation 

and Wildlife sections of this analysis.

Opportunities for quality recreation experiences depend on both the settings (physical, social, and 

managerial aspects), and on the desired experience of the visitor. Conflicts occur when one recreationist 

effects or degrades the experience of another. Many non-motorized recreationists experience conflict with 

motorized recreationists (Adams and McCool 2010). Conflict can result in displacement or the 

abandonment of the use of a particular trail or area, or a change in time of use (Adams and McCool 2010). 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

111

Conflict related to noise may result if non-motorized recreationists are not able to achieve their desired 

experience due to the presence of noise from motorized use in the area. 

Sound is a physical phenomenon, a vibration in the air that can be measured. Noise is an interpretation of 

sound, or a sound that has characteristics that may irritate or annoy a listener, interfere with a listener’s 

activity, or in some other way be distinguished as unwanted (Harrison et al. 1980). 

The acoustic impact of sound can be determined by measuring the inherent characteristics of the sound 

and considering that in conjunction with the setting in which the sound is heard and the individual 

attributes of the listener. Whether sounds are determined to be acceptable, or are interpreted as noise 

depends on the values and desires of the person making the judgement (Harrison et al. 1980).

As noted in the Recreation section of this document, conflict between motorized and non-motorized 

winter uses arise due to differing desired recreation experiences, public safety concerns, noise, air quality, 

and access issues. Public comments received during the scoping period for this analysis describe conflicts 

related to the creation of noise impacts that lead to the displacement of non-motorized recreationists.

Areas of specific concern to non-motorized enthusiasts who are typically seeking a quiet recreation 

setting that is not influenced by the sound of motorized vehicles include cross-country ski trails, the PCT, 

Wilderness, and Semi-Primitive Non-motorized ROS classes.

Generally, human-related sounds are more appropriate toward the rural and roaded end of the ROS 

spectrum and less toward the Semi-Primitive Non-motorized and Primitive end of the spectrum (Harrison 

et al. 2008). ROS classes are described in the Recreation section of this analysis.

California Vehicle Code Section 27203 limits noise at 82 dBA for snowmobiles manufactured after 1972. 

Noise levels generated by OSVs are further limited through manufacturer restrictions. Snowmobiles 

produced since February 1, 1975, and certified by the Snowmobile Safety and Certification Committee’s 

independent testing company emit no more than 78 dBA from a distance of 50 feet while traveling at full 

throttle when tested under the Society of Automotive Engineers (SAE) J192 procedures. Additionally, 

those produced after June 30, 1976, and certified by the Snowmobile Safety and Certification 

Committee’s independent testing company emit no more than 73 dBA at 50 feet while traveling at 15 mph 

when tested under SAE J1161 procedures (California Department of Parks and Recreation 2010).

Sound Propagation

Sound is measured by amplitude (decibels, dB) that determine loudness, frequency (Hertz, Hz) that 

determine pitch, and duration of the sound.

As sound waves travel away from the source, they lose energy (amplitude decreases). Several factors 

influence how far the sound will travel. Spherical spreading loss refers to the fact that a sounds loudness 

decreases as the distance between the source and the listener increases. Atmospheric absorption loss 

refers to sound waves being transferred to, or absorbed by the atmosphere. This varies with air 

temperature, elevation, relative humidity, vegetation and ground cover. Long distance loss refers to 

refraction of sound due to varying air temperatures or wind directions and diffraction or scattering of 

sound waves around a barrier (Harrison et al. 1980).

Background or ambient sound levels influence how noticeable a given sound will be, and the setting in 

which it is heard influences how appropriate that sound may be.
Over-snow Vehicle Use Designation 

Tahoe National Forest

112

Environmental Consequences

Alternative 1 

Direct and Indirect Effects

Under alternative 1, 636,002 acres would be designated for OSV use and the associated influence of OSV 

noise. Noise sources of multiple OSVs and vehicles would be concentrated at plowed OSV trailheads, and 

more dispersed along groomed trails. Approximately 212,857 acres, or 33 percent, of the 636,002 acres 

would be designated for OSV use, such as areas adjacent to groomed OSV trails and areas with highly 

desirable slope and vegetation conditions are anticipated to have high to moderate OSV use levels and the 

associated potential noise impacts. 

Existing conflicts between motorized and non-motorized winter experiences on the Tahoe National Forest

would continue and may increase as population and visitor use increase.

The Pacific Crest National Scenic Trail would continue to be managed as a non-motorized trail, however 

OSV use adjacent to the trail could impact the winter non-motorized trail experience due to noise and the 

presence of OSVs near the trail, or crossing the trail. No OSV trails across the PCT would be designated 

and OSVs would continue to cross the trail along existing OSV routes, and could cross the PCT at any 

location where the trail passes through and OSV open area. The portion of the PCTl on the Tahoe 

National Forest that passes through the Granite Chief Wilderness and other areas where OSV use is 

currently prohibited would continue to provide opportunities for quite non-motorized trail experiences.

Ongoing OSV use near designated non-motorized areas could result in short-term impacts to solitude. 

OSV use across, and adjacent to the PCT would continue, with the potential for ongoing noise-related 

impacts to non-motorized trail visitors, when OSVs are present near the trail.

Table 34. Noise resource indicators and measures for alternative 1

Resource Element Resource Indicator

(Quantify if possible)

Measure

(Quantify if possible) Existing Condition

Noise Opportunities for 

motorized winter uses

Size of areas (acres) open to 

public, cross-country OSV 

use

Acres and percent of 

designated acres that are 

anticipated to have high to 

moderate OSV use levels and 

the associated potential for 

noise impacts.

636,002 acres designated for 

public, cross-country OSV use 

212,857 acres, 33 percent of the 

designated acres are anticipated 

to have high to moderate OSV 

use

Noise OSV designations Length of snow trails (miles), 

groomed and ungroomed, 

designated and identified for 

public OSV use.

217 miles of designated trails 

available for grooming for OSV 

use

41 miles of marked, ungroomed 

trails for OSV use are located 

within areas designated for OSV 

use. 

Approximately 7 miles of 

designated OSV trails are not 

available for grooming.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

113

Cumulative Effects 

In alternative 1, both motorized and non-motorized winter use would continue to occur on trails and in 

areas across the forest, existing conflicts between these uses and desired experiences would continue in 

some popular areas. Short-term and temporary impacts to opportunities for solitude (due to OSV noise, 

and the presence of people) may occur when OSVs are present adjacent to Wilderness areas, within 

Inventoried Roadless Areas, or adjacent to the PCT. Noise from OSVs in areas and on trails across the 

forest would add to other sound sources, such as OSV grooming equipment, snow plows, vehicles on 

highways, vehicles on Forest roads, equipment being used for forest management projects, etc. 

Alternative 2 – Modified Proposed Action

Direct and Indirect Effects 

Under alternative 2, 406,895 acres would be designated for OSV use and the associated influence of OSV 

noise. Noise sources of multiple OSVs and vehicles would be concentrated at plowed OSV trailheads, and 

more dispersed along groomed trails and in designated areas. Approximately 194,311 acres, or 47 percent

of the 406,895 acres designated for OSV use, such as areas adjacent to groomed OSV trails and areas with 

highly desirable slope and vegetation conditions are anticipated to have high to moderate OSV use levels 

and the associated possible noise impacts. 

Using average environmental factors for the winter season on the Tahoe National Forest and the SPreADGIS model, figure 7, figure 8, and figure 9 show the anticipated sound propagation away from point 

source sound locations along OSV trails. The trail points represent a snapshot in time, and were selected 

based on important non-motorized trails and areas. OSV sound source points shown on figure 7, figure 8, 

and figure 9 include the Andesite Ridge OSV trail, locations where OSV trails cross the PCT, and areas 

near the Peter Grubb Hut in Round Valley could be impacted by OSV noise. The noise propagation 

contour lines on the maps show how the OSV sound is expected to spread out from the source location 

given unique environmental, vegetation, and terrain conditions. The maps also show noise levels where 

the introduced OSV noise would be in excess of ambient sound conditions.

Using average environmental factors for the winter season on the Tahoe National Forest and the SPreADGIS model, figure 7, figure 8, and figure 9 show the anticipated sound propagation away from point 

source sound locations along OSV trails. The trail points represent a snapshot in time, and were selected 

based on important non-motorized trails and areas. OSV sound source points shown on figure 7, figure 8, 

and figure 9 include Castle Pass and areas near the Peter Grubb Hut in Round Valley in the Donner 

Summit OSV area, locations where OSV trails cross the PCT in the Barker OSV area, and near French 

Meadows on the Mosquito Ridge trail in the Foresthill East OSV area that are potentially impacted by 

OSV noise. The noise propagation contour lines on the maps show how the OSV sound is expected to 

spread out from the source location given unique environmental, vegetation and terrain conditions. The 

contour lines are color coded to show the extent ofnoise levels where the introduced OSV noise would be 

above ambient sound conditions. Table 35 shows examples of common sounds and their decibel level.
Over-snow Vehicle Use Designation 

Tahoe National Forest

114

Table 35. Examples of Comparative Sound Levels*

Sound Source Sound Level dB(A)

75-piece orchestra 130

Car horn, snow blower 110

Pre-1969 snowmobile 102

Blow dryer, diesel truck 100

Electric shaver, lawn mower 85

Garbage disposal, vacuum cleaner 80

Post-1975 snowmobile (full throttle and 50 feet; 

maximum allowed by law)

78

Alarm clock, city traffic 70

Dishwasher 60

Leaves rustling, refrigerator 40

*Table from American Council of Snowmobiles Associations Facts and Myths about Snowmobiling and Winter Trails, 2014

Figure 7 shows the sound of OSVs on the Andesite Ridge trail spreading primarily to the west, away from 

the Peter Grubb Hutt area, although some noise disturbance is likely when OSVs are present on the 

groomed trail and adjacent areas that are designated for OSV use.

Although sounds of OSVs may be heard in the far western portion of the Granite Chief Wilderness (as 

shown in figure 8) when OSVs are present on designated trails, noise is not anticipated to negatively

impact the wilderness area since the presence of OSV noise would be short-term and temporary when 

OSVs are present on these trails. Little OSV use is anticipated near the wilderness.

Alternative 2 designates OSV use in areas adjacent to PCT segments within the Northeast Yuba, 

Sierraville West, Truckee, and Barker OSV analysis areas. Alternative 2 does not designate any areas for 

OSV use adjacent to the PCT segments within the Donner Summit, Summit West, and Granite Chief 

Wilderness OSV analysis areas. Alternative 2 designates 20 OSV trails across the PCT located in the 

Barker, Sierraville West and Yuba Northeast OSV analysis areas. Figure 9 shows the location of one of the 

trails across the PCT in the Barker Area. Designating OSV trails across the PCT would minimize the 

potential for motorized use to impact the trail experience, and is consistent with the PCT comprehensive 

management plan. Limiting the locations where OSVs cross the trail would enhance the quiet, nonmotorized experience while accommodating motorized access to OSV areas and maintaining OSV loop 

riding opportunities. 

The winter trailhead at Donner Summit is the most popular way to access the PCT going either north or 

south in the wintertime, and OSV use would not be designated in areas adjacent to the PCT where nonmotorized recreationists would generally travel on a day-trip. Also, OSV use would not be designated in 

areas along the PCT (both north and south) where it crosses Highway 49 east of Sierra City, again to 

mitigate potential noise conflicts along the PCT where winter visitors might access the Trail.

Alternative 2 would minimize potential motorized OSV impacts to the non-motorized PCT experience to 

a greater extent than alternatives 1 and 4, but does not provide as much protection of the non-motorized 

PCT experience as in Alternatives 3 and 5. The proposed areas to be designated, and not designated for 

OSV use along the PCT provide for multiple uses along the trail, while also giving consideration to the 

existence of the trail and uses of the trail, consistent with the management direction for the PCT in the 

Tahoe Forest Plan. The potential for noise impacts would be highest near the designated OSV trails 

across the PCT because OSV use could be relatively more concentrated in those areas, at least temporarily 

while OSVs were crossing the trail. 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

115

Additionally, in alternative 2, OSV use would not be designated, and opportunities for solitude and quiet, 

non-motorized experiences would be enhanced in the following areas: High Loch Leven area and the 

individual parcels of National Forest System lands currently under long-term special use permits for 

Royal Gorge Cross Country Ski Area, Tahoe Donner Cross Country Ski Area, Boreal Ski Area, Donner 

Ski Ranch Ski Area, Sugar Bowl Ski Area, Alpine Meadows Ski Area and Squaw Valley Ski Area.

Ongoing monitoring for use conflicts would consider the influence of noise on recreational experiences.

Site-specific sound modeling with the SPreAD-GIS program may be useful to analyze individual areas if 

future conflicts are identified through monitoring. The sound propagation model would help determine 

appropriate actions to help mitigate the conflicts related to noise.

Table 36. Resource indicators and measures for alternative 2 direct and indirect effects

Resource 

Element Resource Indicator Measure

(Quantify if possible)

Alternative 2

Direct and Indirect Effects

Noise Opportunities for 

motorized winter uses

Size of areas (acres) designated

to public, cross-country OSV 

use; percentage change 

compared to current 

management

Acres and percent of designated 

acres that are anticipated to have 

high to moderate OSV use levels 

and the associated potential for 

noise impacts.

406,895 acres designated for OSV 

use, 36 percent decrease from 

current management

191,311 acres, 47 percent of the 

designated acres are anticipated to 

have high to moderate OSV use

OSV designations Length of snow trails (miles), 

groomed and ungroomed, 

designated and identified for 

public OSV use

237 miles of designated trails 

available for grooming for OSV use

14 miles of designated marked trails 

for OSV use

70 miles of designated OSV trails 

not available for grooming
Over-snow Vehicle Use Designation 

Tahoe National Forest

116

Figure 7. Noise analysis on the Andesite Ridge trail
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

117

Figure 8. Noise analysis for the French Meadows Area
Over-snow Vehicle Use Designation 

Tahoe National Forest

118

Figure 9. Noise analysis for the Barker Pass Area
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

119

Cumulative Effects 

The trailhead and parking lot plowing activities and OSV trail grooming activities would increase the 

noise associated with motorized vehicles in the forest setting, however this would not be a change from 

existing conditions. Parking lot plowing occurs during the day when OSV use also typically occurs, so the 

sounds generated by each activity could be cumulative. OSV trail grooming generally occurs at night 

when very few or no OSVs are operating, therefore, the noise impacts from trail grooming would be less 

likely to be cumulative with other motor vehicle sounds, but may be more noticeable because the ambient 

sound conditions are typically quieter during the night.

Non-motorized winter visitors to the Tahoe National Forest could experience noise from OSVs, in 

addition to other noise such as snow plows, vehicles on roads, and aircraft that may be in the same area at 

the same time, cumulatively impacting the quiet recreation experience in the short term.

Alternative 3 

Direct and Indirect Effects 

Under alternative 3, 275,972 acres would be designated for OSV use and the associated influence of OSV 

noise. Noise sources of multiple OSVs and vehicles would be concentrated at plowed OSV trailheads, and 

more dispersed along groomed trails and in areas designated for OSV use. Approximately 161,919 acres, 

or 58 percent of the 275,972 acres designated for OSV use, such as areas adjacent to groomed OSV trails 

and areas with highly desirable slope and vegetation conditions are anticipated to have high to moderate 

OSV use levels and the associated possible noise impacts.

Noise impacts associated with the groomed and ungroomed OSV trail system in alternative 3 would be 

slightly less than in alternative 2.

Alternative 3 would designate OSV use on fewer acres than alternative 2. With additional areas where 

OSV use would not be designated, the opportunities for non-motorized use (in areas not influenced by the 

sounds of OSV use) are enhanced under this alternative.

Alternative 3 would substantially reduce the acres designated for OSV use in the Donner Summit area, 

and would not designate the Andesite West OSV Trail, thus reducing noise disturbance in this area, as 

shown in figure 7. 

Although sounds of OSVs may be heard in the far western portion of the Granite Chief Wilderness (as 

shown in figure 8) when OSVs are present on trails outside the Wilderness, noise is not anticipated to 

negatively impact the Granite Chief Wilderness area because OSV noise would be short-term and 

temporary. Alternative 3 substantially reduces the acres designated for OSV use in the Foresthill East 

OSV area, further reducing associated noise impacts in this area. OSV use would not be anticipated near 

the Wilderness due to its long distance away for designated OSV areas and trails.

Alternative 3 generally does not designate any OSV use in areas directly adjacent to the PCT. In the 

Northeast Yuba and Sierraville West OSV analysis areas, the closest designated OSV areas are 

approximately 1⁄4 to 1⁄2 mile away from the PCT, the closest designated area to the PCT in the Donner 

Summit OSV area is approximately 1.5 miles away, and the closest designated area in the Truckee OSV 

area is approximately 3 miles away. No OSV use is designated in the Summit West, Granite Chief, or

Barker OSV areas in alternative 3. Three OSV trails across the PCT would be designated over roads that 

are on the Tahoe National Forest Motor Vehicle Use Map, in the Sierraville West OSV analysis area. 

Fewer OSV trails across the PCT would be designated than in all other alternatives, further minimizing 
Over-snow Vehicle Use Designation 

Tahoe National Forest

120

the potential for OSVs to impact the non-motorized trail experience and would reduce OSV connectivity 

between designated areas on either side of the PCT. Alternative 3 minimizes impacts to the non-motorized 

PCT experience to a greater extent than alternatives 1, 2, and 4, and is similar to alternative 5.

Alternative 3 would not designate OSV use or OSV trails across the PCT in the Barker OSV area, 

therefore, the experience of non-motorized visitors along the PCT south of the Granite Chief Wilderness 

would not be influenced by the noise from OSVs as shown in figure 9.

In addition to the areas described in alternative 2, OSV use would not be designated, and opportunities for 

solitude and quiet, non-motorized experiences would be enhanced in the following areas: expanded areas 

around Independence Lake, and High Loch Leven(Sierraville West OSV area). New areas not proposed 

for OSV use designation under alternative 3 include Andesite Ridge and Summit Lake, Coon Canyon, 

Donner South, Sardine Lakes, Lunch Creek East, PCT/Grubb, and Devil’s Oven (in the Donner Summit 

and Sierraville East OSV areas), further enhancing quiet, non-motorized opportunities in these areas.

Designating OSV use limited to designated trails through the Lunch Creek East, Southwest Andesite 

Ridge, and Prosser-Boca areas (Donner Summit and Reservoirs OSV areas) provides an opportunity to 

minimize impacts on non-motorized recreation experience, while also maintaining access and 

opportunities for motorized OSV use. 

Potential impacts from OSV noise would be reduced along the entire length of the PCT, different than

described in alternative 2 which avoids designating OSV use in areas most likely to have noise conflicts 

between motorized and non-motorized witner recreation uses. With only three designated OSV trails 

across the PCT, the potential noise disturbance near designated OSV trails across the PCT would be 

limited to a smaller portion of the PCT.

Table 37. Resource indicators and measures for alternative 3 direct and indirect effects

Resource 

Element Resource Indicator Measure

(Quantify if possible)

Alternative 3

Direct and ndirect Effects

Noise Opportunities for 

motorized winter uses

Size of areas (acres) designated 

for OSV use; percentage change 

compared to current 

management 

Acres and percent of designated 

acres that are anticipated to have 

high to moderate OSV use levels 

and associated noise impacts.

275,972 acres designated for OSV 

use, a 57 percent decrease from 

current management

161,919 acres, 58 percent of the 

designated acres are anticipated to 

have high to moderate OSV use

OSV designations Length of snow trails (miles), 

groomed and ungroomed, 

designated and identified for 

public OSV use 

217 miles of designated trails 

available for grooming for OSV use

38 miles of designated marked trails 

for OSV use

24 miles designated OSV trails not 

available for grooming

Cumulative Effects

Activities contributing to potential cumulative effects of alternative 3 would generally be the same as 

those described for alternative 2; however, with fewer acres designated for cross-country OSV use and 

fewer miles of trail available for grooming, the potential for cumulative noise impacts is reduced under 

alternative 3 compared to alternatives 1, 2, and 4.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

121

Alternative 4

Direct and Indirect Effects 

Under alternative 4, 641,105 acres would be designated for to OSV use and the associated influence of 

OSV noise. Noise sources of multiple OSVs and vehicles would be concentrated at plowed OSV 

trailheads, and more dispersed along groomed trails and in designated OSV use aeas. Approximately

212,873 acres, or 33 percent of the 641,105 acres desginated for OSV use, such as areas adjacent to 

groomed OSV trails and areas with highly desirable slope and vegetation conditions are anticipated to 

have high to moderate OSV use levels and associated noise impacts.

Alternative 4 would designate OSV use on more acres and miles of trail than all other alternatives

therefore, it has the highest potential for conflicts with OSV noise across the forest.

Potential noise-related impacts as shown in figure 7, figure 8, and figure 9 would be substantially the 

same as described for alternative 2. Additional acres would be designated for OSV use in the Foresthill 

East OSV area, therefore, possibly increasing the impacts associated with noise in this area. 

Alternative 4 designates OSV use in areas adjacent to PCT segments within the Northeast Yuba, 

Sierraville West, Donner Summit, Summit West, Truckee, and Barker OSV analysis areas. Alternative 4 

does not designate any areas for OSV use adjacent to the PCT segments within the Granite Chief 

Wilderness OSV analysis area. Alternative 4 designates 21 OSV trails across the PCT located in the 

Barker, Sierraville West and Yuba Northeast OSV analysis areas. Potential impacts from OSV noise 

would continue along the PCT, similar to alternative 1.Potential impacts to the non-motorized trail 

experience along the PCT would be slightly more than in alternative 2, and substantaially more than in 

alternatives 3 and 5.

Table 38. Resource indicators and measures for alternative 4 direct and indirect effects

Resource 

Element Resource Indicator Measure

(Quantify if possible)

Alternative 4

Direct and Indirect Effects

Noise Opportunities for 

motorized winter uses

Size of areas (acres) designated 

for OSV use; percentage change 

compared to current 

management 

Acres and percent of designated 

acres that are anticipated to have 

high to moderate OSV use levels 

and associated noise impacts.

641,105 acres designated for OSV 

use, a 0.5 percent increase from 

current management.

212,873 acres, 33 percent of the 

designated acres are anticipated to 

have high to moderate OSV use

OSV designations Length of snow trails (miles), 

groomed and ungroomed, 

designated and identified for 

public OSV use 

259 miles of designated trails 

available for grooming for OSV use

22 miles of designated marked trails 

for OSV use

5 miles of designated trails not 

available for grooming

Cumulative Effects

Activities contributing to potential cumulative noise effects of alternative 4 would be generally the same 

as those described for alternative 2; however, similar acreages designated for cross-country OSV use and 
Over-snow Vehicle Use Designation 

Tahoe National Forest

122

miles of trail available for grooming as Alternative 1, the potential for cumulative noise impacts is similar 

to alternative 1 and relatively higher compared to alternatives 2, 3, and 5.

Alternative 5

Direct and Indirect Effects

Under alternative 5, 300,146 acres would be designated for to OSV use and the associated influence of 

OSV noise. Noise sources of multiple OSVs and vehicles would be concentrated at plowed OSV 

trailheads, and more dispersed along groomed trails and in designated OSV use areas. Approximately 

145,420 acres, or 48 percent of the 300,146 acres designated for OSV use, such as areas adjacent to 

groomed OSV trails and areas with highly desirable slope and vegetation conditions are anticipated to 

have high to moderate OSV use levels and associated noise impacts.

Alternative 5 would designate OSV use on slightly more acres than alternative 3, but on fewer miles of 

trail.

With additional areas not designated for OSV use, the opportunities for non-motorized use (in areas not 

influenced by sounds of OSV use) are enhanced.

Potential impacts from noise would be substantially the same as described in alternative 3 for the Donner 

Summit and Foresthill East areas. Potential impacts from noise would be similar to those described in 

alternatives 2 and 4 for the Barker OSV area (figure 9), but on slightly fewer acres than in alternatives 2 

and 4.

Quiet recreation opportunities would be maintained to the greatest extent of all alternatives along the PCT 

by not designating OSV use within the USFS Scenery Management System definition of Foreground for 

the Pacific Crest National Scenic Trail. This area would be up to one-half mile in the visible lands on each 

side of the Pacific Crest National Scenic Trail or smaller as the visible landscape along the Trail would be 

less than one-half mile on each side of the trail due to topography (in the Northeast Yuba, Sierraville 

West, Donner Summit, Truckee and Barker OSV analysis areas). Alternative 5 does not designate any 

OSV use areas in the Summit West and Granite Chief Wilderness OSV Analysis areas. This would protect 

the trail experience for PCT visitors and would eliminate the potential for OSV use to impact the trail 

experience (other than on the 10 designated OSV trails across the PCT) and reduce the potential for 

conflict between motorized and non-motorized uses. Overall, alternative 5 would minimize potential 

impacts from OSVs on the non-motorized trail experience to a similar extent as in alternative 3, and 

substantially more than in alternatives 1, 2, and 4.to the greatest extent of all alternatives.

Table 39. Resource indicators and measures for alternative 5 direct and indirect effects

Resource 

Element Resource Indicator Measure(Quantify if possible)

Alternative 5

Direct and Indirect Effects

Noise Opportunities for 

motorized winter uses

Size of areas (acres) designated 

for OSV use; percentage change 

compared to current 

management 

Acres and percent of designated 

acres that are anticipated to have 

high to moderate OSV use levels 

and associated noise impacts.

300,146 acres designated for OSV 

use, a 53 percent decrease from 

existing conditions

145,420 acres, 48 percent of the 

designated acres are anticipated to 

have high to moderate OSV use
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

123

Resource 

Element Resource Indicator Measure

(Quantify if possible)

Alternative 5

Direct and Indirect Effects

Noise OSV designations Length of snow trails (miles), 

groomed and ungroomed, 

designated and identified for 

public OSV use 

215 miles of designated trails 

available for grooming for OSV use

25 miles of marked, ungroomed trails 

for OSV use

17 miles of designated OSV trails not 

available for grooming

Cumulative Effects 

Activities contributing to potential cumulative noise effects of alternative 5 would be generally the same 

as those described for alternative 2; however, with fewer acres designated for cross-country OSV use

(with the fewest acres anticipated for moderate to high OSV use), and fewer miles of trail available for 

grooming, the potential for cumulative noise impacts is reduced to the greatest extent under Alternative 5 

of all alternatives.

Summary of Environmental Effects

Alternatives 1, 3, and 5 provide approximately the same level of groomed motorized OSV trail 

opportunities, as found in current management, and therefore, the same degree of possible noise impacts 

associated with trail use. Alternatives 2 and 4 increase the miles of trails available for grooming, and 

therefore, increase the possibility of noise impacts associated with trail use. Cross-country travel, and use 

of OSV trails is limited by minimum snow depth requirements for all action alternatives; however, 

alternative 2 provides most flexibility in applying the snow depth requirements. This flexibility allows 

OSV access to higher elevations provided snow depths are adequate to avoid resource damage, typically a 

minimum of 12 inches for cross-country OSV travel. Alternative 4 designates the greatest acreage for

OSV use forestwide, compared to alternatives 2, 3, and 5, and therefore, the greatest possibility of noise 

impacts across the forest. The acres and percentage of designated acres that are anticipated to have high to 

moderate OSV use in alternative 4, are approximately the same as in alternative 1, existing conditions. 

Alternative 5 is expected to have the least amount of acres that could be impacted by noise due to fewer 

acres anticipated to receive high to moderate OSV use. 

Compliance with LRMP and Other Relevant Laws, Regulations, Policies 

and Plans 

Alternative 1 would not comply with Subpart C of the Travel Management rule that requires designation 

of roads, trails, and areas on National Forest System lands to provide for over-snow vehicle use.

Alternatives 2, 3, 4, and 5 would comply with Subpart C of the Travel Management rule and would 

require amendments to the Tahoe Forest Plan’s standards and guidelines for OSV use designation.
Over-snow Vehicle Use Designation 

Tahoe National Forest

124

Table 40. Summary comparison of how the alternatives address the key issues for noise

Issue Indicator/Measure Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Noise Opportunities for 

motorized winter 

uses

Size of areas 

(acres) designated 

for OSV use that 

could be affected by 

noise; percentage 

change compared to 

current 

management

Acres and percent 

of designated acres 

that are anticipated 

to have high to 

moderate OSV use 

levels and 

associated noise 

impacts

636,002 acres 

designated for 

OSV use

212,857 acres, 

33 percent of the 

designated acres 

are anticipated to 

have high to 

moderate OSV 

use.

198,271 acres not 

designated for 

OSV use and 

available for quiet 

recreation

1,218 acres 

seasonally 

designated for 

OSV use and 

available for quiet 

recreation when 

OSVs are not 

present

406,895 acres 

designated for OSV 

use, a 36 percent 

decrease from 

existing conditions.

191,311 acres, 

47 percent of the 

designated acres 

are anticipated to 

have high to

moderate OSV use.

429,378 acres not 

designated for OSV 

use and available 

for quiet recreation

275,972 acres 

designated for OSV 

use, a 57 percent 

decrease from existing 

conditions.

161,919 acres, 

58 percent of the 

designated acres are 

anticipated to have high 

to moderate OSV use. 

560,301 acres not 

designated for OSV use 

and available for quiet 

recreation

1,408 acres seasonally 

designated for OSV use 

and available for quiet 

recreation when OSVs 

are not present

641,105 acres 

designated for OSV use, 

a.5 percent increase 

from existing conditions.

212,873 acres, 

33 percent of the 

designated acres are 

anticipated to have high 

to moderate OSV use.

195,168 acres not 

designated for OSV use 

and available for quiet 

recreation

1,218 acres seasonally 

designated for OSV use 

and available for quiet 

recreation when OSVs 

are not present

300,146 acres 

designated for OSV 

use; a 

53 percent decrease 

from existing 

conditions.

145,420 acres, 

48 percent of the 

designated acres are 

anticipated to have 

high to moderate OSV 

use

536,127 acres not 

designated for OSV 

use and available for 

quiet recreation

OSV designations

Length of snow trails 

(miles), groomed 

and ungroomed, 

designated and 

identified for public 

OSV use

217 miles available 

for grooming

41 miles marked, 

ungroomed

7 miles designated, 

not available for 

grooming

237 miles available 

for grooming

14 miles marked, 

ungroomed

70 miles designated, 

not available for 

grooming

217 miles available for 

grooming

38 miles marked, 

ungroomed

25 miles designated, 

not available for 

grooming

259 miles available for 

grooming

22 miles marked, 

ungroomed

5 miles designated, not 

available for grooming

215 miles available for 

grooming

25 miles marked, 

ungroomed

17 miles designated, 

not available for 

grooming
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

125

Air Quality

Relevant Laws, Regulations, and Policy

Regulatory Framework

Land and Resource Management Plan

The Tahoe National Forest Land and Resource Management Plan (LRMP 1990) provides standards and 

guidelines for Air Quality.

• No quantifiable value is placed on air quality. The Federal Clean Air Act sets standards and guidelines 

for the attainment and maintenance of air quality (LRMP page 63). 

Federal Clean Air Act 

In 1963, Congress passed the Federal Clean Air Act and amended the act in 1970, 1977, and 1990. The 

purpose of the act is to protect and enhance air quality while ensuring the protection of public health and 

welfare. The 1970 amendments established National Ambient Air Quality Standards (NAAQS), which 

must be met by most state and Federal agencies, including the Forest Service.

States are given the primary responsibility for air quality management. Section 110 of the Clean Air Act 

requires states to develop state implementation plans that identify how the State will attain and maintain 

NAAQS. The Clean Air Act also allows states, and some counties, to adopt unique permitting procedures 

and to apply more stringent standards. California has set standards for certain pollutants, such as 

particulate matter and ozone, which are more protective of public health than respective Federal 

standards. California has also set standards for some pollutants that are not addressed by Federal 

standards including sulfates, hydrogen sulfide, vinyl chloride, and visibility-reducing particles.

The Clean Air Act requires that Forest Service actions have “no adverse effect” on air resources by 

meeting the NAAQS and non-degradation standards for Class 1 areas. Managers are further directed to 

improve existing substandard conditions and reverse negative trends where practicable. The NAAQS and 

California Ambient Air Quality Standards (CAAQS) for particle pollution as set by the Clean Air Act and 

California Air Resources Board can be viewed online at the California Air Resources Board webpage.10

National Ambient Air Quality Standards 

NAAQS requirements were established to protect human health and the environment and acceptable 

maximum air quality concentrations. The NAAQS consist of numerical standards for air pollution, which 

are broken into “primary” and “secondary” standards for six major air pollutants described below. 

Primary standards protect public health (including sensitive populations such as asthmatics, children, and 

the elderly) and represent levels at which there are no known major effects on human health. Secondary 

standards are intended to protect the nation’s welfare, and account for air pollutant effects on soil, water, 

visibility, materials, vegetation, and other aspects of the environment. These standards are detailed in 

table 41 and accompanying footnotes.

California Air Resources Board

California law authorizes the California Air Resources Board to set ambient (outdoor) air pollution 

standards (California Health and Safety Code section 39606) in consideration of public health, safety, and 

welfare. The Air Resources Board has established State Ambient Air Quality Standards (CAAQS) to 

 10 http://www.arb.ca.gov/research/aaqs/aaqs2.pdf
Over-snow Vehicle Use Designation 

Tahoe National Forest

126

identify outdoor pollutant levels considered safe for the public. After State standards are established, State 

law requires the Air Resources Board to designate each area as attainment, nonattainment, or unclassified 

for each State standard. The area designations, which are based on the most recent available data, indicate 

the healthfulness of air quality throughout the State (ARB 2015). The State and National Ambient Air 

Quality Standards are displayed in table 41 and accompanying footnotes. 

The California Air Resources Board is responsible for meeting the Clean Air Act requirements. The Air 

Resources Board has further delegated the authority to local Air Pollution Control Districts (APCDs) or 

Air Quality Management Districts (AQMDs) for stationary sources, while retaining the authority for 

mobile sources. Air quality rules and regulations for California can be found at 

http://www.arb.ca.gov/homepage.htm. The APCD/AQMD has the primary responsibility for meeting the 

requirements of the Clean Air Act. This responsibility is carried out through the development and 

execution of state implementation plans, which must provide for the attainment and maintenance of air 

quality standards. 

State implementation plans are comprehensive plans that describe how an area will attain NAAQS. The 

1990 amendments to the Federal Clean Air Act set deadlines for attainment based on the severity of an 

area's air pollution problem.

State implementation plans are a compilation of new and previously submitted plans, programs, district 

rules, state regulations and Federal controls. State law makes the Air Resources Board the lead agency for 

all purposes related to the state implementation plan. Local air districts and other agencies prepare state 

implementation plan elements and submit them to the Air Resources Board for review and approval. The 

Air Resources Board forwards state implementation plan revisions to the Environmental Protection 

Agency (EPA) for approval and publication in the Federal Register. The Code of Federal Regulations 

Title 40, Chapter I, Part 52, Subpart F, Section 52.220 lists all of the items that are included in the 

California State Implementation Plan (http://www.arb.ca.gov/planning/sip/background.htm). The Forest 

Service is required to comply with all requirements of the California State Implementation Plan. 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

127

Table 41. State and National Ambient Air Quality Standards

Pollutant Averaging California Standards1 National Standards2

Time Concentration3 Method4 Primary3,5 Secondary3,6 Method7

Ozone (O3)8

1 hour 0.09 ppm 

(180 μg/m3)

Ultraviolet 

Photometry --- Same as Primary Standard

Ultraviolet 

Photometry

8 hour 0.070 ppm 

(137 μg/m3)

0.070 ppm 

(137 μg/m3)

Respirable 

Particulate 

Matter 

(PM10)9

24 hour 50 μg/m3

Gravimetric or Beta 

Attenuation

150 μg/m3

Same as Primary 

Standard

Inertial Separation 

and Gravimetric 

Analysis

Annual 

Arithmetic 

Mean

20 μg/m3 ---

Fine 

Particulate 

Matter 

(PM2.5)9

24 hour --- --- 35 μg/m3

Same as Primary 

Standard

Inertial Separation 

and Gravimetric 

Analysis

Annual 

Arithmetic 

Mean

12 μg/m3 Gravimetric or Beta 

Attenuation

12.0 μg/m3 15 μg/m3

Carbon

1 hour 20 ppm (23 

mg/m3)

35 ppm 

(40 mg/m3)

---

Non-dispersive

Monoxide 8 hour 9.0 ppm(10 

mg/m3)

Non-dispersive 

Infrared Photometry

9 ppm 

(10 mg/m3)

--- Infrared Photometry

(CO) 8 hour (Lake 

Tahoe)

6 ppm (7 mg/m3) (NDIR) --- --- (NDIR)

Nitrogen

1 hour 0.18 ppm 

(339 μg/m3) Gas Phase

100 ppb 

(188 μg/m3)

---

Gas Phase

Dioxide

(NO2)

10

Annual 

Arithmetic 

Mean

0.030 ppm 

(57 μg/m3)

Chemiluminescence 0.053 ppm 

(100 μg/m3)

Same as Primary 

Standard

Chemiluminescence

1 hour 0.25 ppm (655 

μg/m3

75 ppb 

(196 μg/m3)

---

3 hour --- Ultraviolet 

Fluorescence

--- 0.5 ppm (1300 

μg/m3)

Ultraviolet 

Fluorescence

Sulfur 

Dioxide 

(SO2)

11

24 hour 0.04 ppm (105 

μg/m3)

0.14 ppm 

(for certain 

areas)10

--- Spectrophotometry 

(Pararosaniline 

Method)

Annual 

Arithmetic 

Mean

--- 0.030 ppm 

(for certain 

areas)10

---

30 Day 

Average

1.5 μg/m3 --- ---

Lead 12,13

Calendar 

Quarter

--- Atomic Absorption 1.5 μg/m3

Same as Primary 

Standard

High Volume 

Sampler and Atomic 

Absorption

Rolling 3-

Month 

Average

--- 0.15 μg/m3

Visibility 

Reducing 

Particles14

8 hour See footnote 14 Beta Attenuation and 

Transmittance 

through Filter Tape No

Sulfates 24 hour 25 μg/m3 Ion Chromatography National 

Hydrogen 

Sulfide

1 hour 0.03 ppm 

(42 μg/m3)

Ultraviolet 

Fluorescence

Standards

Vinyl 

Chloride12

24 hour 0.01 ppm

(26 μg/m3)

Gas 

Chromatography

Source: California Air Resources Board (5/4/16). (See footnotes on next page.)
Over-snow Vehicle Use Designation 

Tahoe National Forest

128

1. California standards for ozone, carbon monoxide (except 8-hour Lake Tahoe), sulfur dioxide (1 and 24 hour), nitrogen

dioxide, and particulate matter (PM10, PM2.5, and visibility reducing particles), are values that are not to be exceeded.

All others are not to be equaled or exceeded. California ambient air quality standards are listed in the Table of Standards

in Section 70200 of Title 17 of the California Code of Regulations.

2. National standards (other than ozone, particulate matter, and those based on annual arithmetic mean) are not to be

exceeded more than once a year. The ozone standard is attained when the fourth highest 8-hour concentration

measured at each site in a year, averaged over three years, is equal to or less than the standard. For PM10, the 24-hour

standard is attained when the expected number of days per calendar year with a 24-hour average concentration above

150 μg/m3 is equal to or less than one. For PM2.5, the 24 hour standard is attained when 98 percent of the daily

concentrations, averaged over three years, are equal to or less than the standard. Contact the U.S. EPA for further

clarification and current national policies.

3. Concentration expressed first in units in which it was promulgated. Equivalent units given in parentheses are based upon

a reference temperature of 25 °C and a reference pressure of 760 torr. Most measurements of air quality are to be

corrected to a reference temperature of 25°C and a reference pressure of 760 torr; ppm in this table refers to ppm by

volume, or micromoles of pollutant per mole of gas.

4. Any equivalent measurement method which can be shown to the satisfaction of the ARB to give equivalent results at or

near the level of the air quality standard may be used.

5. National Primary Standards: The levels of air quality necessary, with an adequate margin of safety to protect the public

health.

6. National Secondary Standards: The levels of air quality necessary to protect the public welfare from any known or

anticipated adverse

7. Reference method as described by the U.S. EPA. An “equivalent method” of measurement may be used but must have a

“consistent relationship to the reference method” and must be approved by the U.S. EPA.

8. On October 1, 2015, the national 8-hour ozone primary and secondary standards were lowered from 0.075 to 0.070 ppm.

9. On December 14, 2012, the national annual PM2.5 primary standard was lowered from 15 μg/m3 to 12.0 μg/m3

. The 

existing national 24-hour PM2.5 standards (primary and secondary) were retained at 35 μg/m3

, as was the annual 

secondary standard of 15 μg/m3

. The existing 24-hour PM10 standards (primary and secondary) of 150 μg/m3 also were 

retained. The form of the annual primary and secondary standards is the annual mean, averaged over 3 years.

10. To attain the 1-hour national standard, the 3-year average of the annual 98th percentile of the 1-hour daily maximum

concentrations at each site must not exceed 100 ppb. Note that the national 1-hour standard is in units of parts per billion

(ppb). California standards are in units of parts per million (ppm). To directly compare the national 1-hour standard to the

California standards the units can be converted from ppb to ppm. In this case, the national standard of 100 ppb is

identical to 0.100 ppm.

11. On June 2, 2010, a new 1-hour SO2 standard was established and the existing 24-hour and annual primary standards 

were revoked. To attain the 1-hour national standard, the 3-year average of the annual 99th percentile of the 1-hour daily 

maximum concentrations at each site must not exceed 75 ppb. The 1971 SO2 national standards (24-hour and annual) 

remain in effect until one year after an area is designated for the 2010 standard, except that in areas designated 

nonattainment for the 1971 standards, the 1971 standards remain in effect until implementation plans to attain or maintain 

the 2010 standards are approved.

Note that the 1-hour national standard is in units of parts per billion (ppb). California standards are in units of parts per

million (ppm). To directly compare the 1-hour national standard to the California standard the units can be converted to

ppm. In this case, the national standard of 75 ppb is identical to 0.075 ppm.

12. The ARB has identified lead and vinyl chloride as 'toxic air contaminants' with no threshold level of exposure for adverse 

health effects determined. These actions allow for the implementation of control measures at levels below the ambient 

concentrations specified for these pollutants.

13. The national standard for lead was revised on October 15, 2008, to a rolling 3-month average. The 1978 lead standard 

(1.5 μg/m3 as a quarterly average) remains in effect until one year after an area is designated for the 2008 standard, 

except that in areas designated nonattainment for the 1978 standard, the 1978 standard remains in effect until 

implementation plans to attain or maintain the 2008 standard are approved.

14. In 1989, the ARB converted both the general statewide 10-mile visibility standard and the Lake Tahoe 30-mile visibility 

standard to instrumental equivalents, which are "extinction of 0.23 per kilometer" and "extinction of 0.07 per kilometer" for 

the statewide and Lake Tahoe Air Basin standards, respectively.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

129

Regional Haze Rule (1990 Clean Air Act Amendments, 40 CFR Part 5)

The Federal Clean Air Act of 1977 declared a national goal to remedy existing visibility impairment 

and prevent future haze caused by man-made air pollution at selected national parks and wilderness 

areas of the United States, known as Class 1 Areas. California has 29 mandatory Class 1 Areas 

managed by either the National Parks Service or the U.S. Forest Service (more than any other state). 

In 1999, the Environmental Protection Agency promulgated a regional haze regulation (40 CFR 

51.308-309) that calls for states to establish goals and emission reduction strategies to make initial 

improvements in visibility at their respective Class 1 Areas. Visibility variation occurs as a result of 

the scattering and absorption of light by particles and gases in the atmosphere. It also mandates each 

state to develop a Regional Haze State Implementation Plan to incorporate measures necessary to 

make reasonable progress towards national visibility goals. In 2009, the Air Resources Board 

prepared a Regional Haze Plan for California demonstrating reasonable progress in reducing haze by 

2018, the first benchmark year on the path to improved visibility. The Environmental Protection 

Agency funded five Regional Planning Organizations throughout the country to coordinate regional 

haze rule-related activities between states in each region. California belongs to the Western Regional 

Air Partnership (WRAP), the consensus organization of western states, tribes, and Federal agencies, 

which oversees analyses of monitoring data and preparation of technical reports regarding regional 

haze in the western United States. (See figure 11.)

Criteria Pollutants Regulated by EPA

Ozone (O3) is the most widespread air quality problem in the state. It is an important ingredient of 

smog and is a highly reactive and unstable gas capable of damaging the linings of the respiratory 

tract. This pollutant forms in the atmosphere through complex reactions between chemicals directly 

emitted from vehicles, industrial plants, and many other sources. Exposure to levels of ozone above 

the current ambient air quality standard can lead to human health effects such as lung inflammation 

and tissue damage and impaired lung functioning. The ozone that California Air Resources Board

regulates as an air pollutant is produced close to the ground level, where people live, exercise and 

breathe. The concern about ozone pollution is its effects on the health of Californians and the 

environment (ARB 2015). 

In April 2005, the Air Resources Board approved a new 8-hour standard of 0.070 ppm and retained 

the 1-hour ozone standard of 0.09 after an extensive review of the scientific literature. (ARB 2015)

Particulate Matter 2.5 (PM2.5) is the term for particles found in the air, including dust, dirt, soot, 

smoke and liquid droplets. Many manmade and natural sources emit PM directly or emit other 

pollutants that react in the atmosphere to form PM. Particles less than 10 micrometers pose a health 

concern because they can be inhaled into and accumulate in the respiratory system. PM2.5 are 

referred to as “fine” particles and believed to pose the greatest health risks. Sources include motor 

vehicles, power plants, wood burning. (Source: EPA.gov)

Particulate Matter 10 (PM10) are the larger particles between 2.5 and 10 micrometers found in the 

air including smoke and dust from factories, farming, roads, mold, spores and pollen. Major concerns 

for human health from exposure to PM10 include: effects on breathing and respiratory systems, 

damage to lung tissue, cancer, and premature death. Acidic PM10 can also damage human-made 

materials and is a major cause of reduced visibility in many parts of the U.S. (Source: EPA.gov)

Lead (Pb) is a metal found naturally in the environment as well as in manufactured products. The 

major sources of lead emissions have historically been from fuels emitted by on-road motor vehicles 

(such as cars and trucks) and industrial sources. As a result of the EPA's regulatory efforts to remove 
Over-snow Vehicle Use Designation 

Tahoe National Forest

130

lead from on-road motor vehicle gasoline, emissions of lead from the transportation sector 

dramatically declined by 95 percent between 1980 and 1999, and levels of lead in the air decreased 

by 94 percent between 1980 and 1999. Today, the highest levels of lead in air are usually found near 

lead smelters. The major sources of lead emissions to the air today are ore and metals processing and 

piston-engine aircraft operating on leaded aviation gasoline. (Source: EPA.gov)

Nitrogen Dioxide (NO2) is emitted from motor vehicles, industrial facilities, and power plants. 

Home heaters and gas stoves also produce substantial amounts of NO2. In the summer months NO2 is 

a major component of photochemical smog and an essential ingredient in the formation of groundlevel ozone pollution. Exposure to NO2 along with other traffic-related pollutants, is associated with 

respiratory symptoms, episodes of respiratory illness and impaired lung functioning. In February 

2007, the Air Resources Board established a new annual average NO2 standard of 0.030 ppm and 

lowered the 1-hour NO2 standard to 0.18 ppm, after an extensive review of the scientific literature.

(Source: ARB 2015).

Carbon Monoxide is a byproduct of incomplete combustion and is emitted directly into the 

atmosphere, primarily from motor vehicle exhaust. Carbon monoxide concentrations typically peak 

nearest a source, such as roadways, and decrease rapidly as distance from the source increases. 

Carbon monoxide is readily absorbed into the body from the lungs. It decreases the capacity of the 

blood to transport oxygen, leading to health risks for unborn children and people suffering from heart 

and lung disease. The symptoms of excessive exposure such as headaches, fatigue, slow reflexes, 

and dizziness also occur in healthy people. (Source: ARB 2015) 

Sulfur Dioxide (SO2) is primarily a combustion product of coal, fuel oil, and diesel fuel. Only small 

quantities of SO2 come from gasoline fueled motor vehicle exhaust. Sulfur dioxide is emitted directly 

into the atmosphere and can remain suspended for days allowing for wide distribution of the 

pollutant. Sulfur dioxide can trigger constriction of the airways, causing particular difficulties for 

asthmatics. Children can experience increased respiratory tract infections and healthy people may 

experience sore throats, coughing, and breathing difficulties. Long-term exposure has been 

associated with increased risk of mortality from respiratory or cardiovascular disease. (Source: ARB 

2015).

The California Air Resources Board has monitored the gaseous criteria pollutants carbon monoxide, 

nitrogen dioxide, ozone, and sulfur dioxide since its inception in 1968. Monitoring is performed to 

demonstrate attainment or non-attainment of national and state ambient air quality standards.

Desired Condition 

Desired conditions are to manage activities so that air quality meets the standards under Federal, 

State, and local laws (LRMP page 99). Activities permitted on Tahoe National Forest System lands 

will support State and local objectives for air quality. As new technology is developed to control 

automobile and industrial emissions, air quality on the Tahoe should improve (LRMP page 103).

Resource Indicators and Measures 

The air quality analysis is a qualitative discussion of the potential contribution of OSV emissions 

from the estimated number of visitors to the Tahoe each year.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

131

Methodology

Information Sources 

Information sources used for this analysis are listed below and represent some of best available 

information that was available at the time of report writing.

• ArcMap and relevant GIS data layers from the Tahoe National Forest, Environmental Protection 

Agency and the California Air Resources Board were used. Including county boundaries, air 

basin boundaries, air district boundaries and class 1 and 2 areas.

• GIS layer of proposed OSV designations and groomed trails.

• Tahoe National Forest Plan (LRMP 1990).

• Scientific literature cited in the “References” section.

• The National Visitor Use Monitoring information for the Tahoe National Forest.

• OSV use was from the 2009 OSV Winter Trailhead Survey conducted in support of the 2010 

State OSV Program Environmental Impact Report for Program Years 2010-2020.

• Information and correspondence obtained from the California Air Resources Board.

OSV Use Assumptions for Analysis

For analysis purposes, snowmobile emission data used was obtained from the Environmental 

Protection Agency (EPA 2010). Analysis was based on emission estimates for a 2-stroke 

snowmobile (worst-case scenario). Snowmobile miles traveled per day was estimated at 50 miles per 

day and was averaged based on the responses received through a survey forum (snowest.com). 

Assuming a 4 percent average annual increase in use, the projected Seasonal OSV Use-days for the 

Tahoe National Forest for 2016 would be 20,859 for OSV program trailheads. Primarily day use 

(generally 10:00 am to 3:00 pm; grooming occurs at night. OSV use is highest on weekends and 

holidays. Highest concentration of OSV use occurs along groomed trails (supposed by research

documented in State EIR (Valentine 2016a).

Spatial and Temporal Context for Effects Analysis

Spatial Context:

The spatial boundaries for analyzing the direct and indirect effects to air quality are within the Tahoe 

National Forest boundary, because the proposed OSV designation decision would apply to OSV use 

and its possible effects to air quality on the forest.

The spatial boundaries for analyzing cumulative effects to air quality are within the Tahoe National 

Forest boundary, because the proposed OSV designation decision would apply to OSV use and its 

potential to cumulatively impact air quality on the forest.

Effects Timeframe:

The temporal boundaries for analyzing the direct and indirect effects to air quality is one OSV 

season. This was chosen in order to analyze the effects of OSV emissions within the Tahoe for one 

winter season and used to compare emissions generated in air districts per year.
Over-snow Vehicle Use Designation 

Tahoe National Forest

132

Affected Environment

Existing Condition 

California is divided geographically into air basins for the purpose of managing the air resources of 

the State on a regional basis. An air basin generally has similar meteorological and geographic 

conditions throughout. The State is currently divided into 15 air basins, the Tahoe National Forest is 

located within the Mountain Counties Air Basin, with a small portion of Yuba County within the 

Sacramento Valley Air Basin (figure 10). 

Figure 10. Designated air basins in California

Air Pollution Control Districts/Air Quality Management Districts

Air quality for the forest is managed and regulated by air pollution control or air quality management 

districts. These districts were created by state law to enforce local, state and Federal air pollution 

regulations. The Tahoe National Forest lies within Plumas, Placer, Sierra, Nevada and Yuba 

Counties. The Feather River Air Quality Management District administers air quality management 

programs for Yuba County within the Sacramento Valley Air Basin and encompasses a small western 

portion of the Tahoe National Forest. The Northern Sierra Air Quality Management District manages 

air quality programs for Nevada, Sierra and Plumas Counties. The majority of the Tahoe National 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

133

Forest lies within this district. The Placer Air Pollution Control District manages air quality programs 

and air standards for Placer County and lies within the approximate southern third of the Tahoe 

National Forest. Air quality rules and regulations for each air pollution control district can be found 

at their websites. Figure 8 below depicts where the air pollution districts lie within the Tahoe 

National Forest.

Class I and II Areas

There is one Class I area, the Desolation Wilderness, lies south of the Tahoe National Forest

boundary. All areas within the Tahoe National Forest are classified as Class II, including the Granite 

Chief Wilderness. The nearest source of local emissions is probably the Lake Tahoe basin,

immediately east of the Desolation Wilderness. However, most of the wilderness is not part of the 

nearby Lake Tahoe airshed, although easternmost east-facing slopes are (ARB 2016). Section 160-

169 of the Clean Air Act established a detailed policy and to protect the quality of the air in regions 

of the United States in which the air is cleaner than required by the NAAQS. One purpose of the 

Clean Air Act’s regulatory program is the Prevention of Significant Deterioration and to preserve, 

protect and enhance air quality in national parks and national wilderness areas. Through this 

program, Congress established a land classification scheme for those areas with air quality better 

than the NAAQS. Class I allows very little deterioration of air quality, Class II allows moderate 

deterioration and Class III allows more deteriorations. In all cases, the pollution concentrations shall 

not violate NAAQS.

Visibility impairment is defined as any humanly perceptible change in visual air quality from that

which would have existed under natural conditions (in other words, absent anthropogenic influence).

Sources for visibility impairment in these Class I areas include, but are not limited to, industrial 

sources, on-road and off-road vehicle emissions, road dust, windblown dust, and smoke. Sources can

be local or very distant. Progress toward better visibility is calculated from data collected at the 

Interagency Monitoring of Protected Visual Environments (IMPROVE) network. The IMPROVE 

monitors measure the concentration of each haze-causing pollutant every three days. There are 17 

IMPROVE monitors representing one or more of the Class I Areas in California. The BLIS1 monitor 

location represents two wilderness areas located along the crest of the Sierra Nevada mountain range, 

just west of Lake Tahoe. The wilderness areas associated with the BLIS1 monitor are Desolation 

Wilderness area and Mokelumne Wilderness area (within the Stanislaus, Eldorado, and Toiyabe 

National Forests). The BLIS1 site has been operating since November 1990 (ARB 2016).

However, the Air Resources Board also noted, as evidenced by reductions in anthropogenic source 

emissions in California and the concurrent improvement in visibility at all of California’s Class 1 

Area IMPROVE monitors, that the current Regional Haze plan strategies are sufficient for California 

and its neighboring states to meet their 2018 Reasonable Progress Goals (ARB 2014).
Over-snow Vehicle Use Designation 

Tahoe National Forest

134

Figure 11. Class I areas in California

Air Quality Standards

The Tahoe National Forest must comply with Federal and State ambient air quality standards as 

mandated by the Clean Air Act of 1963. These standards have been established for seven criteria air

pollutants: carbon monoxide (CO), lead (Pb), nitrogen dioxide (NO2), PM10, PM2.5, ozone (O3), and

sulfur dioxide (SO2). California also has standards in place for sulfates, hydrogen sulfide, visibilityreducing particles and vinyl chloride (ARB 2015). 

These pollutants can affect human health, reduce visibility, and lead to acidic deposition in sensitive,

high-elevation lakes. Air quality within the Tahoe National Forest could be affected by land

management and development activities both on and off the forest. Sources of air pollutants include

forest management activities such as wildland fires (both natural and management ignited), road dust,

and vehicle emissions. These sources, as well as industrial sources and emissions from urban

developments are also found outside Forest Service administered lands.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

135

Currently, the Tahoe National Forest complies with Federal and State standards and there are no 

known violations of the Clean Air Act. According to the EPA, the Sacramento Metro area of Placer 

County is in nonattainment for 8-hour ozone and the western portion of Nevada County is also in 

nonattainment for ozone. The remaining counties and air districts are in attainment or unclassified 

for the other criteria pollutants. The concern for ozone is in the summer only according to the Air 

Pollution Specialist at the Air Resources Board (Lopina 2015). Please see table 42.

Table 42. Federal non-attainment areas for criteria pollutants

County

and/or Air 

District

8-hour 

Ozone

Carbon 

Monoxide 

(CO)

Lead (Pb)

Particulate 

Matter 2.5

(PM2.5)

Particulate 

Matter 10

(PM10)

Nitrogen 

Dioxide 

(NO2)

Sulfur 

Dioxide 

(SO2)

Placer N

(Sacramento 

Metro area)

U/A U/A U U U/A U

Plumas U/A U/A U/A U U U/A U

Nevada N (Western 

part of Co)

U/A U/A U U U/A U

Sierra U/A U/A U/A U U U/A U

Yuba U/A U/A U/A U U U/A U

Source: http://www.arb.ca.gov/ei/gislib/gislib.htm (Accessed: June 2016)

A=Attainment; N=Non-attainment; U=Unclassified

Table 43 shows the California Ambient Air Quality Standards state designations for all criteria 

pollutants in California. The Air Resources Board makes state area designations for 10 criteria 

pollutants: ozone, suspended particulate matter (PM10), fine suspended particulate matter (PM2.5), 

carbon monoxide, nitrogen dioxide, sulfur dioxide, sulfates, lead, hydrogen sulfide, and visibilityreducing particles (ARB 2015). The Air Resources Board lists three counties in non-attainment for 

ozone. The remaining counties are in attainment or unclassified for the criteria pollutants.

For ozone, PM2.5, and PM10, the required minimum number of monitors is based on the population of 

the Core-Based Statistical Area (CBSA) and the severity of the pollutant concentrations of each 

CBSA. The table below summarizes the required and existing ozone, PM2.5, and PM10 monitors 

for 11 CBSAs. In all cases, sufficient monitoring exists and no additional monitoring is required 

(ARB 2015) (see table 44).
Over-snow Vehicle Use Designation 

Tahoe National Forest

136

Table 43. State designated non-attainment areas for criteria pollutants

County and/ 

or Air 

District

Ozone (O3)

Carbon 

Monoxide 

(CO)

Lead (Pb) PM2.5 PM10

Nitrogen 

Dioxide 

(NO2)

Sulfur 

Dioxide 

(SO2)

Sulfates Hydrogen 

Sulfide

Visibility 

Reducing 

Particles

Placer N U A U A A A A U U

Plumas U A A U A A A A U U

Nevada N U A U A A A A U U

Sierra U U A U A A A A U U

Yuba N-transitional U A A A A A A U U

Source: http://www.arb.ca.gov/ei/gislib/gislib.htm Accessed: June 2016

A=Attainment; N=Non-attainment; U=Unclassified
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

137

Table 44. Number of required and existing sites by CBSA

CBSA Population Ozone PM2.5 PM10 (SSI)3

Required Existing Required Existing Required Existing Required Existing

SLAMS1 SLAMS SLAMS SLAMS Cont.2 Cont. SLAMS SLAMS

Bakersfield* 839,361 2 8 2 5 1 3 4-8 4

Chico 220,000 1 2 0 1 1 3 N/A N/A

Los AngelesLong BeachAnaheim*

12,828,837 4 16 3 11 2 7 2-4 8

Redding 177,223 1 4 0 1 0 0 0 3

Riverside-San

BernardinoOntario*

4,224,851 3 21 3 10 2 8 6-10 12

Sacramento- Arden 

Arcade- Roseville* 2,149,127 2 17 3 6 2 9 6-10 10

Santa Rosa* 483,878 1 2 0 1 0 1 N/A N/A

VallejoFairfield^ 413,344 2 3 0 1 0 1 0-1 1

Yuba City 166,892 1 2 0 1 0 1 N/A N/A

El Centro 174,528 1 3 1 3 1 1 1-2 5

OxnardThousand

Oaks-Ventura

823,318 2 5 1 5 1 5 N/A N/A

Source: ARB 2015

2012-2014 air quality data was used in determining the number of required sites. This table excludes tribal monitoring sites.

Population is based on year 2010 Census data.

*Parts of these MSAs are included in the geographical scope of this report, and parts are within the geographical scope of the reports being completed by the districts.

The numbers of sites listed are for the entire CBSA. See Table 3a for a completed list of CBAs in California.

1 SLAMS: State and Local Air Monitoring Stations.

2 Cont.: Refers to a continuous PM2.5 monitor, i.e., one that measures hourly data.

For this assessment, both continuous FEMs and non-FEMs are counted for each CBSA.

3 SSI: Size Selective Inlet. The SSI is an FRM for PM10. N/A means there is no PM10 monitor in the CBSA.

^The PM2.5 FRM monitor at Vallejo was discontinued in March 2011 and was replaced with a continuous PM2.5 FEM monitor.
Over-snow Vehicle Use Designation 

Tahoe National Forest

138

The table below displays the annual average emissions (tons per year) generated for the air districts 

within the Tahoe National Forest (EPA 2013).

Table 45. Estimated annual average emissions (tons/year) by air district for area-wide, stationary and 

mobile sources

Air District TOG ROG CO NOx SOx PM PM10 PM2.5

Placer APCD 22,403.7 7,639.45 31,922.9 8,230.75 98.55 9,453.5 5,445.8 1,781.2

Northern Sierra AQMD

(Nevada, Sierra, Plumas 

Counties)

10,577.7 5,131.9 33,572.7 4,796.1 270.1 12,380.8 7,577.4 1,952.75

Feather River AQMD (Yuba 

County**)

11,453.7 5,500.55 19,520.2 73,070.3 204.4 10,318.55 5,653.85 1,843.25

TOTAL Emissions for Air 

Districts (tons/year)

44,435.1 18,271.9 85,015.8 86,097.15 573.05 32,152.85 18,677.05 5,577.2

Source: http://www.arb.ca.gov/ei/maps/statemap/dismap.htm. Accessed July 19, 2016

**Feather River emissions estimates also includes emissions from Sutter County, not within the Tahoe National Forest.

Snowmobile Emission Standards

In 2002, the EPA issued a regulation that imposed stringent pollution regulations on snowmobiles, 

requiring that snowmobiles fall under regulations of the Clean Air Act (Jehl 2002). In 2012, 

snowmobile manufacturers were required to meet one of two alternatives. One would require 

reductions in emissions of both hydrocarbons and carbon monoxide by 50 percent from current 

levels. The other is intended to encourage further reductions in hydrocarbons and would require a 

70 percent reduction in hydrocarbons, the source of the more urgent health concerns, in return for a 

30 percent reduction in carbon monoxide (Jehl 2002)

The EPA also requires that manufacturers ensure each new engine, vehicle, or equipment meets the 

latest emission standards. Once manufacturers sell a certified product, no further effort is required to 

complete certification. If products were built before EPA emission standards started to apply, they are 

generally not affected by the standards or other regulatory requirements (EPA 20153).
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

139

Table 46. Exhaust emission standards for snowmobiles

Phase Model year Phase-in

(percent)

Emission standards Maximum allowable family 

emission limits

HC CO HC CO

Phase 1 2006 50 100 275

Phase 1 2007-2009 100 100 275

Phase 2 2010 and 2011 100 75 275

Phase 3 2012 and later 100 (

1) (1) 150 400

Source: Code of Federal Regulations, Accessed November 2015 

1 See § 1051.103(a)(2):

(a) * * *

(1) Follow Table 1 of this section for exhaust emission standards. You may generate or use emission credits under the 

averaging, banking, and trading (ABT) program for HC and CO emissions, as described in subpart H of this part. This 

requires that you specify a family emission limit for each pollutant you include in the ABT program for each engine family. 

These family emission limits serve as the emission standards for the engine family with respect to all required testing 

instead of the standards specified in this section. An engine family meets emission standards even if its family emission 

limit is higher than the standard, as long as you show that the whole averaging set of applicable engine families meets 

the applicable emission standards using emission credits, and the vehicles within the family meet the family emission 

limit. The phase-in values specify the percentage of your U.S.-directed production that must comply with the emission 

standards for those model years. Calculate this compliance percentage based on a simple count of your U.S.-directed 

production units within each certified engine family compared with a simple count of your total U.S.-directed production 

units. Table 1 also shows the maximum value you may specify for a family emission limit, as follows:

(2) For Phase 3, the HC and CO standards are defined by a functional relationship. Choose your corporate average HC 

and CO standards for each year according to the following criteria: 

https://www.federalregister.gov/articles/2008/06/25/E8-14411/exhaust-emission-standards-for-2012-and-later-modelyear-snowmobiles

Best Available Technology

Snowmobiles must be certified by the National Park Service to enter some National Parks 

(Yellowstone, Grand Teton). Best available technology certification is one of the most stringent 

standards for air and noise emissions in the world, requiring hydrocarbon emissions of less than 

15 g/kW-hr, carbon monoxide emissions of less than 120 g/kW-hr, and sound level limited to 

73 decibels (BRP 2011). The use of certified snowmobiles, which result in lower CO and 

hydrocarbon emissions (NPS 2013), is not currently required on the Tahoe National Forest. The 

Forest Service has no regulatory jurisdiction over air quality or noise.

Motorized Winter Recreation

Table 47 is derived from the OSV trailhead survey conducted for the State EIR, and based on data 

summarized in the State EIR (California Department of Park and Recreation 2010). The table shows 

the average number of vehicles at trailheads, and the average number of OSVs that would be 

expected on weekends and holidays versus weekdays. Based on this information, estimated use per 

winter season would be 22,410 OSV users forestwide. However, visitor use levels vary by season 

depending on the amount of snowfall, adequate snow depths, and length of season. The season is 

from mid-December through March (approximately 14 weeks), which is equivalent to approximately 

33 weekend/holidays and 65 weekdays. In 2010, snowmobiling was reported as a main activity for 

1.7 percent, and in 2005 snowmobiling was reported as a main activity for 7 percent (Valentine 

2016b). 
Over-snow Vehicle Use Designation 

Tahoe National Forest

140

Table 47. Tahoe National Forest OSV visitor use

Location Day description Number of 

vehicles

Number of 

OSVs*

Forestwide Weekend or holiday (approx. 33 per season) 202 404

Forestwide Weekday (approx. 65 per season) 40 80

Grooming activities

Currently, there are approximately 217 miles of National Forest System trails that are groomed for 

OSV use on the Tahoe National Forest. Snow trail grooming for OSV use typically occurs December 

through March. Snowcats are used for grooming OSV trails and grooming operations are typically 

conducted during the night or during low use timeframes. The California OHMVR Division’s 

snowcat fleet is subject to emission regulation by the California Air Resources Board (CARB) as offroad equipment. The CARB sets an emission limit for the vehicle fleet as a whole rather than for 

individual pieces of equipment. Based on the total horsepower of the vehicle fleet, and the model and 

year of the individual equipment within the fleet, CARB determines how much horsepower per year 

must be repowered, retrofitted, or retired. The California OHMVR Division then determines what 

modifications to make to its fleet in order to satisfy CARB requirements.

Table 48. Resource indicators and measures for air quality, existing condition 

Resource 

Element Resource Indicator Measure Existing Condition/Alternative 1

Air Quality Estimate of change (increase or decrease) 

in emissions and the possibility of

adversely impacting air quality.

Miles of trail 

designatd for OSV 

use 

265

Estimate of change (increase or decrease) 

in emissions and the possibility of 

adversely impacting air quality.

Acres designated for

OSV use 

636,002

Potential effects of OSV emissions to 

create adverse impacts to air quality.

Shifts in OSV use in 

relation to sensitive 

areas (Class II and II 

areas).

No known impacts to 

air quality or 

NAAQS/CAAQS 

violations exist.

Environmental Consequences

Alternative 1 

Direct and Indirect Effects

Land management and development activities on and off the forest can affect the air quality on the

Tahoe National Forest. Air pollution sources include emissions from mobile and stationary sources 

including industrial activity, highway vehicles, and off-road vehicles (all-terrain vehicles, aircraft,

locomotives, construction machinery). Airborne dust and smoke from burning can also significantly

impact air quality as they occur on and off the forest. These sources can emit a host of regulated 

pollutants in and around the forest. Currently, good dispersion and topographic influences on the 

forest have resulted in no violations of Federal and State Ambient Air Quality Standards and have 

not attained concentrations high enough to warrant measurement or to result in degradation of air 

quality in the Class I area.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

141

Three factors, largely beyond State control, can interfere with air quality in Class I Areas: wildfire 

smoke, offshore shipping emissions, and Asian dust. These factors are either from natural sources 

(wildfire smoke), uncontrollable sources (shipping emissions beyond California’s jurisdiction), or 

both (Asian dust, a combination of anthropogenic and natural sources beyond California’s control) 

(ARB 2014).

Table 49 displays the potential contribution of snowmobile emissions from the estimated 

22,410 OSV visitors that recreate on the Tahoe National Forest each year. All calculations were done 

using emission estimates from a 2-stroke snowmobile (EPA 2010). As shown in table 49, it is 

estimated current emissions generated as a result of OSV use on the Tahoe National Forest 

contributes approximately 0.43 percent of carbon monoxide (CO) to the air districts under alternative 

1, and less than 0.01 percent of nitrogen oxide (NOx) and particulate matter (PM). These emissions 

are minor compared to other sources of air pollution impacting the forest. Impacts to air quality 

include vehicle emissions such as nitrogen oxides, particulate matter, and carbon monoxide from all 

motorized vehicles including snowmobiles and snowcats. Diesel engines also emit sulfur oxides and 

particulates. Air quality impacts from vehicle emissions are influenced by the effectiveness of smog 

control devices on cars, amount of traffic, and how long engines idle. As people recreate in the forest 

during the winter months, the effects of vehicle exhaust on air quality may become a localized 

temporary issue where concentrated motorized use conflicts with non-motorized uses and nuisance 

smell occurs.

Table 49. Emission estimate (tons per year) for OSV use on the Tahoe National Forest

Source Number of 

OSVs Miles* CO NOx PM

Snowmobile (2-stroke) 22,410 50 365.60 1.06 3.33

% Pollutant Contribution 

to Air Districts

------- ---- 0.43% Less than 0.01 Less than 0.01

*Assumes 22,410 OSVs recreate on the Tahoe per year and travel an average of 50 miles.

Alternative 2

Direct and Indirect Effects

Alternative 2 would designate OSV use on fewer acres than alternative 1 (406,895 acres versus 

636,002 acres, respectively). This is approximately a 36 percent reduction in acres designated for 

OSV use forestwide as compared to the existing condition. 

For the Tahoe National Forest, an estimated 22,410 OSV visitors forestwide for the winter season 

would equate to approximately 229 OSV visitors on the forest per day (using 33 weekend/holidays 

and 65 weekdays per season) utilizing 321 miles of trail and 406,895 acres for OSV use. That is 

equivalent to approximately one OSV visitor per 1,776 acres. It is expected OSV emissions would 

dissipate and the possibility of accumulation would be eliminated based on topographic influences 

and wind dispersion. Non-motorized users’ air quality concerns in parking lots, at trailheads and on 

trails would continue since non-motorized and motorized users would still share the same parking 

areas, trailheads and many of the same trails. The odor generated by emissions from combustion 

engines, particularly two-cycle engines, can diminish a non-motorized user’s experience. However, 

this is likely a recreation (user satisfaction) issue rather than a general air quality issue (see 

Recreation report for more discussion on the topic of visitor experience). Bishop et al. (2006) found 
Over-snow Vehicle Use Designation 

Tahoe National Forest

142

emissions were greatest during initial startup and idling, especially when the engine is cold. They 

also observed reducing wait times at entrance stations would further lower emissions and exposure.

Implementing similar measures or idling limits at parking lots and trailheads, may address public 

concerns regarding nuisance smell and possible impacts to air quality in those areas. It is anticipated 

any impacts to air quality from winter motorized recreation under alternative 2 would not result in 

any violations to National and State Ambient Air Quality Standards.

Musselman and Korfmacher (2007) conducted a study in Wyoming to evaluate the effects of winter 

recreation snowmobile activity on air quality at a high-elevation site. They measured levels of 

nitrogen oxides (NOx, NO), carbon monoxide (CO), ozone (O3) and particulate matter (PM10 mass). 

They found nitrogen oxides and carbon monoxide were significantly higher on weekends than 

weekdays due to higher snowmobile use on weekends. Ozone and particulate matter were not 

significantly different during the weekend compared to weekdays. Air quality data during the 

summer were also compared to the winter data and they found carbon monoxide levels at the site 

were significantly higher during the winter than during the summer. Nitrogen oxides and particulates 

were significantly higher during the summer compared to winter. Nevertheless, air pollutants were 

well dispersed and diluted by strong winds common at the site, and snowmobile emissions did not 

have a significant impact on air quality at the site (Musselman and Korfmacher 2007).

Class I and II Areas

Implementation of alternative 2 is expected to maintain the same air quality conditions as compared 

to alternative 1 due to good dispersion characteristics across the forest, low inversion potential, and 

low emissions generated from OSVs as compared to other potential sources. It is anticipated that air 

quality of the Class I area and the Granite Chief Wilderness (Class II area) would be similar to the 

existing condition. Compliance with State and Federal air quality standards is expected to occur under 

alternative 2. Motorized recreation emission sources on the forest are localized, transient, and not

expected to result in any significant air quality impacts under alternative 2. No violations of the Clean 

Air Act are expected to occur.

Cumulative Effects 

Land management and development activities on and off the forest can affect air quality on the 

forest. Air pollution sources include emissions from industrial activity, highway vehicles, and offroad vehicles (all-terrain vehicles, aircraft, locomotives, construction machinery). Airborne dust 

and smoke from burning can also significantly impact air quality as they occur on and off the 

forest. None of the on-forest sources discussed in the existing condition are expected to increase or 

impact air quality when combined with alternative 2. In addition, emissions generated from

snowcats plowing and grooming parking lots and trailheads could contribute to localized air 

pollution on the forest. However, it is estimated the contribution of administrative snowcat use to 

the overall cumulative impacts on air quality would be minimal.

Air quality impacts are expected to grow with continued growth of population around the Tahoe 

National Forest. Substantial impacts to air quality are not expected to occur during winter months 

on the forest due to regulations already in place by the EPA and the Clean Air Act. The past, 

present, and reasonably foreseeable future actions would be the primary contributors to air quality 

impacts on the forest. Due to the short-term and localized impact of OSV use, this alternative is 

not expected to result in a significant contribution to the cumulative impacts of other local and 

regional air pollution sources. However, it is impossible to predict future pollutant discharge from 

off-forest mobile and stationary sources and how those sources may contribute to, or impact air 

quality, on the forest. There are no known unavoidable adverse, irreversible, or irretrievable 

effects to air quality as a result of implementation.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

143

Alternative 3

Direct and Indirect Effects

Alternative 3 would designate OSV use on fewer acres than alternative 1 (275,972 acres versus 

636,002 acres, respectively). This is approximately a 57 percent reduction in acres designated for

OSV use forestwide as compared to the existing condition. 

Cumulative Effects

The cumulative effects discussed for alternative 2 would also apply for alternative 3.

Alternative 4

Direct and Indirect Effects

Under alternative 4 there would be an 8 percent increase (approximately 287) of miles of trail 

designated for OSV use and less than a 1 percent increase of acres designated for OSV use (table 49) 

as compared to alternative 1 (641,105 acres versus 636,002 acres, respectively). The increase in 

miles of trails designated for OSV use may cause a shift in OSV use to other areas. The estimated 

22,410 OSV visitors forestwide for the winter season would equate to approximately 229 OSV 

visitors on the forest per day (using 33 weekend/holidays and 65 weekdays per season) utilizing 

287 miles of trail and 641,105 acres for OSV use. That is equivalent to approximately one OSV 

visitor per 2,779 acres. With the acres designated for OSV use, it is likely emissions generated as a 

result of OSVs would be similar to what is currently estimated under alternative 1.

Cumulative Effects

The cumulative effects discussed for alternative 2 above would also apply for alternative 4.

Alternative 5

Direct and Indirect Effects

Alternative 5 would prohibit OSV use on more acres than alternative 2. This is approximately a 

53 percent reduction in acres designated for OSV use forestwide as compared to the existing 

condition (300,146 acres versus 636,002 acres, respectively). It is likely emissions generated as a 

result of OSVs would be less than what is currently estimated. Current emissions generated as a 

result of OSV use on the Tahoe are estimated to contribute less than approximately 0.0043 percent of 

carbon monoxide (CO) under alternative 1, less than 0.01 percent of nitrogen oxide (NOx), and less 

than 0.01 percent of particulate matter (PM) pollutants to the air districts within the Tahoe National 

Forest. These emissions are minor compared to other sources of air pollution impacting the forest.

Direct and Indirect Effects

The cumulative effects discussed for alternative 2 above would also apply for alternative 5.

Summary

It is expected the levels of pollutants for the all the alternatives would fall within the ranges currently 

experienced and no violation of State or Federal ambient air quality standards would occur during 

the OSV season.
Over-snow Vehicle Use Designation 

Tahoe National Forest

144

OSV use is not designated in Class I areas in all alternatives, and it is anticipated the impacts of OSV 

use on Class I areas would be fairly similar for all action alternatives. It is anticipated 

Compliance with Relevant Laws, Regulations, Policies and Plans 

No known violations of ambient air quality standards have occurred on the forest, nor have any

activities on the forest caused violations of these standards elsewhere. The alternatives comply with 

the Clean Air Act, the National Ambient Air Quality Standards and California Ambient Air Quality 

Standards for criteria pollutants.

Other Relevant Mandatory Disclosures

Unavoidable Adverse Effects 

Authorized OSV use on National Forest System lands, may unavoidably affect the short-term air 

quality in some areas, specifically at trailheads and parking lots. However, it is likely this is a 

nuisance smell issue, rather than an air quality issue.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

145

Hydrology

Relevant Laws, Regulations, and Policy

Regulatory Framework

Land and Resource Management Plan

The 1990 Tahoe National Forest LRMP provides standards and guidelines for water-related concerns.

The following list of standards and guidelines, are a subset of all applicable LRMP direction and this 

plan must be analyzed for consistency to all applicable LRMP standards and guidelines for hydrology.

Table 50. Tahoe National Forest LRMP guidelines relevant to watershed resources

Page Forestwide Guidelines 

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.

LRMP, pg. 27 (Current Management Direction)

The water program mission is to afford optimum protection to the water resources 

compatible with other program practices, including timber, wildlife and fisheries, range, 

recreation, engineering, and mining. Where opportunities arise, watershed improvement 

measures will be implemented and water quantities and timing of flow will be improved 

The water program on the Tahoe NF has primarily served as a support function for other 

resource activities. The various types of support include planning, inventories, analyzing 

project proposals, monitoring, and administration. All existing land management practices 

use the water quality protection measures that are specified as Best Management 

Practices (BMPs) in the R-5 document 'Water Quality Management for National Forest 

System Lands in California,' also referred to as the R-5 Forest Service 208 Plan.

LRMP, pg.V-9 Produce water of sufficient quality and quantity to meet or exceed identified use 

requirements and improve water quality by the year 2030. Maintain or improve soil 

productivity and prevent excessive, cumulative watershed impacts. Conserve soil and 

water resources and prevent activities that will significantly or permanently impair the 

productivity of the land. Protect streams, lakes, wetlands, streamside management 

zones, and other riparian areas.

LRMP, pg.V-9 Desired Future Condition

Greater emphasis on environmental quality will have positive effects on the soil and water 

resources. Specific riparian and streamside guidelines will have maintained current 

riparian conditions. Direct soil and water improvement projects will have stopped the 

decline and In some cases restored or improved the productivity of key watersheds. 

lnstream flow requirements will have protected riparian-dependent communities against 

incompatible water resource development. Greater emphasis on water resources, soil, 

and watershed management will have resulted in greater project success and less impact 

on soil and water resources. Monitoring will provide Information on management-induced 

Impacts on soil and water resources. This knowledge will be used to improve project 

implementation.
Over-snow Vehicle Use Designation 

Tahoe National Forest

146

Page Forestwide Guidelines 

LRMP, pg.V-33 Disturbed Watershed Acres Restored by Limiting intensive Management. Limit intensive 

management (e g , range, timber management, OW'S, etc.) on lands that are in a 

declining hydrologic condition

LRMP, pg.V-35 Water Quality Protection- Use Best Management Practices to meet water quality 

objectives and maintain and improve the quality of surface water on the forest. Methods 

and techniques for applying the BMP will be identified and documented during project 

level environmental assessments and Incorporated into the associated project plan and 

Implementation documents. (See Plan Appendix E.)

LRMP, pg.V-38 Soils/Watershed/Geology Support- Provide watershed input in support of other resource 

activities. This involves various EAs and planning efforts such as timber sales, recreation 

site developments, reforestation planning, range planning and improvement, material 

source development, groundwater development hydroelectric projects, mining 

explorations and operations, sale preparation and administration, and wildlife habitat 

improvement projects. Also, develop and administer plans for soil, water, and geologic 

resource projects (e.g., for special studies, demonstration soil areas, municipal 

watersheds, groundwater and aggregate sources, and river basin studies). Includes soils 

and water resource inventories, soils and water resource monitoring, geologic resources

and hazards inventory, and water uses management (administration of water uses and 

water uses inventory) 

LRMP, pg.V-61 Water Resource improvement- Implement activities to improve watershed conditions. 

These are usually major soil erosion and water quality problem areas that are on the 

forest WIN lnventory Includes erosion reduction: water flow Improvement (e g , reduced 

surface runoff): channel stabilization works; and sediment retention practices This 

involves revegetation with grasses, trees, and shrubs, and associated treatments such as 

mulching, spreading straw and jute: and improvements such as check dams, settling 

basins, and water spreading structures Involves developing water resource improvement 

plans, implementing restoration plans, and maintenance.

Sierra Nevada Forest Plan Amendment

The 2001 Sierra Nevada Framework modified forest plan guidance and established a comprehensive 

aquatic and riparian conservation strategy for all of the national forest lands in the Sierra Nevada. Key 

components of this strategy include riparian buffer zones, critical refuges for threatened and endangered 

aquatic species, special management for large meadows, and a watershed analysis process. 

The framework includes standards and guidelines in national forests for construction and relocation of 

roads and trails and for management of riparian conservation areas. These standards and guidelines

require the Forest Service to avoid road construction, reconstruction, and relocation in meadows and 

wetlands; maintain and restore the hydrologic connectivity of streams, meadows, and wetlands by 

identify roads and trails that intercept, divert, or disrupt flows paths and implementing corrective 

actions; and determine if stream characteristics are within the range of natural variability prior to taking 

actions that could adversely affect streams. 

The framework’s standards and guidelines for riparian conservation areas are intended to minimize the 

risk of activity-related sediment entering aquatic systems. The framework established riparian 

conservation area widths for all Sierra Nevada forests: 300 feet on each side of perennial streams; 150 

feet on each side of intermittent and ephemeral streams; and 300 feet from lakes, meadows, bogs, fens, 

wetlands, vernal pools, and springs.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

147

Riparian Conservation Areas: Activity-related Standards and Guidelines

Where a proposed project encompasses riparian conservation areas or a critical aquatic refuge, conduct a 

site-specific project area analysis to determine the appropriate level of management within the riparian 

conservation area or a critical aquatic refuge. Determine the type and level of allowable management 

activities by assessing how proposed activities measure against the riparian conservation objectives and 

their associated standards and guidelines. Areas included in riparian conservation areas are: 300 feet on 

each side of perennial streams, 150 feet on each side of intermittent and ephemeral streams, and 300 feet 

from lakes, meadow, bogs, fens, wetlands, vernal pools, and springs.

Riparian Conservation Objective 1

Ensure that identified beneficial uses for the water body are adequately protected. Identify the specific 

beneficial uses for the project area, water quality goals from the Regional Basin Plan, and the manner in 

which the standards and guidelines will protect the beneficial uses. Beneficial uses describe how water 

is used and vary by water body. Examples of beneficial uses include water for domestic water supply, 

fire suppression, fish and wildlife habitat, and contact recreation (swimming).

Riparian Conservation Objective 2

Maintain or restore: (1) the geomorphic and biological characteristics of special aquatic features, 

including lakes, meadows, bogs, fend, wetlands, vernal pools, and springs; (2) streams, including in 

stream flows; and (3) hydrologic connectivity both within and between watersheds to provide for the 

habitat needs of aquatic-dependent species.

Standard and Guideline 100: Maintain and restore 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.

Standard and Guideline 101: 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 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.

Standard and Guideline 102: Prior to activities that could adversely affect streams, determine if relevant 

stream characteristics are within the range of natural variability. If characteristics are outside of 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.

Standard and Guideline 103: Prevent disturbance to stream banks and natural lake and pond shorelines 

caused by resource activities (e.g., livestock, off-highway vehicles, and dispersed recreation) from 

exceeding 20 percent of stream reach or 20 percent of natural lake and pond shorelines. Disturbance 

includes bank sloughing, chiseling, trampling, and other means of exposing bare soil or cutting plant 

roots. This standard does not apply to developed recreation sites; sites authorized under special use 

permits, and designated OHV routes.
Over-snow Vehicle Use Designation 

Tahoe National Forest

148

Riparian Conservation Objective 4

Ensure that management activities within riparian conservation areas and critical aquatic refuges 

enhance or maintain physical and biological characteristics associated with aquatic- and ripariandependent species.

Standard and Guideline 116: 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.

Riparian Conservation Objective 5

Preserve, restore, or enhance special aquatic features, such as meadows, lakes, ponds, bogs, fens, and 

wetlands, to provide the ecological conditions and processes needed to recover or enhance the viability 

of species that rely on these areas.

Standard and Guideline 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. Criteria for defining bogs and fens include the 

presence of plants in the genus Meesia, and three sundew species (Drosera spp.). Complete initial plant 

inventories of bogs and fens within grazing allotments prior to re-issuing permits.

Riparian Conservation Objective 6

Identify and implement restoration actions to maintain, restore, or enhance water quality and maintain, 

restore, or enhance habitat for riparian and aquatic species.

Standard and Guideline 122: Recommend restoration practices in: (1) areas with compaction in excess 

of soil quality standards, (2) areas with lowered water tables, or (3) areas that are either actively down 

cutting or that have historic gullies. Identify other management practices that may be contributing to the 

observed degradation, such as road building, recreational use, grazing, and timber harvests.

State Laws

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 (CWC Sections 13000 to 13485) apply to waters on the national forests and are directed at 

protecting the beneficial uses of water. Of particular relevance to the proposed action is Section 13369, 

which deals with non-point-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 Board 

and the Regional Water Quality Control Boards, which are authorized by the U.S. Environmental 

Protection Agency to enforce the Federal Clean Water Act in California.

Sections 208 and 319 of the Federal Clean Water Act address nonpoint source pollution and require 

water quality management plans for nonpoint sources of pollution. The Forest Service in the Pacific 

Southwest Region (Region 5) has worked with the California water quality agencies to meet Clean 

Water Act requirements. The greatest emphasis in this coordination has been on the management and 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

149

control of nonpoint sources of water pollution, with sediment, water temperature, and nutrient levels of 

most concern. The State Water Resources Control Board and Regional Water Quality Control Boards 

entered into agreements with the Forest Service to control nonpoint source discharges by implementing 

BMPs. These BMPs, which are set forth in the Forest Service Pacific Southwest Region guidance 

document, Water Quality Management for Forest System Lands in California, Best Management 

Practices (2000), constitute a portion of the State’s Nonpoint Source Management Plan and comply with 

the requirements of Sections 208 and 319 of the Clean Water Act. The agreements include BMPs related 

to OSV use, and to road construction and maintenance. The implementation and effectiveness of the 

BMPs are reviewed annually. In recent years, the Forest Service has emphasized monitoring in national 

forests to ensure the implemented projects follow approved control measures (USDA Forest Service, 

2004b). 

Pacific Southwest Region Best Management Practices, and National Core Best Management 

Practices

The State and Regional Water Quality Control Boards entered into agreements with the Forest Service 

to control non-point-source discharges by implementing control actions certified by the State Water 

Quality Control Board and the Environmental Protection Agency as best management practices (USDA 

Forest Service R5 FSH 2509.22 - soil and water conservation handbook, 2011). These are designed to 

protect and maintain water quality and prevent adverse effects to beneficial uses, both on site and 

downstream. Further, the Washington Office has generated National Core BMPs that include the 

following BMP listed below for OSV uses.

Through the execution of a formal Management Agency Agreement with the Forest Service in 1981, the 

State Water Resources Control Board designated the Forest Service as the Water Quality Management 

Agency for National Forest System lands in California. The Forest Service BMPs are in conformance 

with the provisions and requirements of the Federal CWA and within the guidelines of the Basin Plans 

developed for the nine Regional Water Quality Control Boards in California. The BMPs most relevant to 

the OSV Program pertain to snow removal and monitoring and include the following: 

BMP 2-25 (USDA Forest Service R5 FSH 2509.22 - Soil and Water Conservation 

Handbook, 2011): Snow Removal Controls to Avoid Resource Damage 

a. Objective: To minimize the impact of snowmelt runoff on road surfaces and embankments and to 

consequently reduce the probability of sediment production resulting from snow removal 

operations. 

b. Explanation: This is a preventative measure used to protect resources and indirectly to protect 

water quality. Forest roads are sometimes used throughout winter for a variety of reasons. For such 

roads the following measures are employed to meet the objectives of this practice.

1. The contractor will be responsible for snow removal in a manner which will protect roads and 

adjacent resources.

2. Rocking or other special surfacing and drainage measures will be necessary before the 

operator is allowed to use the roads.

3. Snow berms will be removed where they result in an accumulation or concentration of 

snowmelt runoff on the road and erosive fill slopes.
Over-snow Vehicle Use Designation 

Tahoe National Forest

150

4. Snow berms will be installed where such placement will preclude concentration of snowmelt 

runoff and serve to rapidly dissipate melt water. If the road surface is damaged during snow 

removal, the purchaser or contractor will be required to replace lost surface material with similar 

quality of material and repair structures damaged in snow removal operations as soon as practical 

unless otherwise agreed to in writing.

c. Implementation: Project location and detailed mitigation will be developed by the 

interdisciplinary team during environmental analysis and incorporate into the project plan and/or 

contracts. Project crew leaders and supervisors will be responsible for implementing force account 

projects to construction specifications and project criteria.

BMP 4-7 (USDA Forest Service 2000): Water Quality Monitoring of OHV (and OSV) 

Use According to a Developed Plan

a. Objective: To provide a systematic process to determine when and to what extent OHV use 

will cause or is causing adverse effects on water quality.

b. Explanation: Each forest’s OHV Plan [Travel Management Plan and LRMP] will:

1. Identify areas or routes where OHV use could cause degradation of water quality.

2. Establish baseline water quality data for normal conditions as a basis from which to 

measure change.

3. Identify water quality standards and the amount of change acceptable. 

4. Establish monitoring measures and frequency.

5. Identify controls and mitigation appropriate in management of OHVs.

6. Restrict OHVs to designated routes.

c. Implementation: Monitoring results are evaluated against the OHV plan objectives for water 

quality and the LRMP objectives for the area. These results are documented along with actions 

necessary to correct identified problems. If considerable adverse effects are occurring, or are 

likely to occur, immediate corrective action will be taken. Corrective actions may include, but 

are not limited to, reduction in the amount of OHV use, signing, or barriers to redistribute use, 

partial closure of areas, rotation of use on areas, closure to causative vehicle type(s), total 

closure, and structural solutions such as culverts and bridges.

National Core BMP Rec-7. Over-Snow Vehicle Use

Reference: FSM 7718

Objective: Avoid, minimize or mitigate adverse effects to soil, water quality and riparian resources from 

over-snow vehicle use. 

Explanation: An over-snow vehicle is a motor vehicle that is designed for use over snow and that runs 

on a track or tracks and/or a ski or skis, while in use over snow. Over-snow vehicles include 

snowmobiles, snow cats, and snow grooming machines. Snowmobiles and snow cats are used for access 

and for recreational activities. Snow grooming machines are used to prepare snow on trails for downhill 

or cross-country skiing or snowmobile use.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

151

An over-snow vehicle traveling over snow results in different impacts to soil and water resources than 

do motor vehicles traveling over the ground. Unlike other motor vehicles traveling cross-country, oversnow vehicles generally do not create a permanent trail or have direct impact on soil and ground 

vegetation when snow depths are sufficient to protect the ground surface. Emissions from over-snow 

vehicles, particularly two-stroke engines on snowmobiles, release pollutants like ammonium, sulfate, 

benzene, PAHs and other toxic compounds that are stored in the snowpack. During spring snowmelt 

runoff, these accumulated pollutants are released and may be delivered to surrounding waterbodies. In 

addition, over-snow vehicles that fall through thin ice can pollute waterbodies. 

Use of National Forest System lands and/or trails by over-snow vehicles may be allowed, restricted or 

prohibited at the discretion of the local line officer.

Practices:

Develop site-specific BMP prescriptions for the following practices, as appropriate or when required, 

using state BMPs, Forest Service regional guidance, Forest or Grassland Plan direction, BMP monitoring 

information and professional judgment:

• Use suitable public relations and information tools, and enforcement measures to encourage the 

public to conduct cross-country over-snow vehicle use and on trails in a manner that will avoid, 

minimize or mitigate adverse effects to soil, water quality and riparian resources.

 Provide information on the hazards of running over-snow vehicles on thin ice.

 Provide information on effects on over-snow vehicle emissions on air quality and water 

quality. 

• Use applicable practices of BMP Rec-4 (Motorized and Non-motorized Trails) when locating, 

designing, constructing and maintaining trails for over-snow vehicle use.

• Allow over-snow vehicle use cross-country or on trails when snow depths are sufficient to 

protect the underlying vegetative cover and soil or trail surface.

 Specify the minimum snow depth for each type or class of over-snow vehicle to protect 

underlying resources as part of any restrictions or prohibitions on over-snow use.

 Specify season-of-use to be at times when the snowpack is expected to be of suitable 

depth.

 Specify over-snow vehicle class suitable for the expected snowpack and terrain or trail 

conditions.

• Use closure orders to mitigate effects when adverse effects to soil, water quality or riparian 

resources are occurring.

• Use applicable practices of BMP Rec-2 (Developed Recreation Sites) and BMP-10 when 

constructing and operating over-snow vehicle trailheads, parking and staging areas. 

 Use suitable measures to trap and treat pollutants from over-snow vehicle emissions in 

snowmelt runoff or locate the staging area at a sufficient distance from nearby 

waterbodies to provide adequate pollutant filtering.
Over-snow Vehicle Use Designation 

Tahoe National Forest

152

Resource Indicators and Measures 

Resource indicators and measures shown in table 19 will be used to measure and disclose effects to 

hydrology related to OSV use designations and grooming trails for OSV use.

Table 51. Resource indicators and measures used to determine impacts on soil and water resources

Resource Element Resource Indicator Measure

(Quantify if possible)

Water quality Number of snowmobiles per year using 

trails across the forest

Total amount of use can be compared to 

use amounts in Yellowstone and other 

studies to gauge potential water quality 

effects 

Consistency with Riparian Conservation 

Objectives 1, 2, 4, 5, and 6

Evaluation of the effects to RCOs, water 

quality and beneficial uses of water

Methodology

Data on OSV routes and uses was compiled from GIS data obtained from the Tahoe National Forest

include the following: 

• GIS analyses of route miles and stream crossings in hydrologically sensitive areas.

• A variety of reports and assessments of OSV impacts, and professional experience and judgement 

using scientific literature on OSV impacts.

• 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 literature–based and anecdotal information documenting the impacts of 

OSV uses and how they may vary based on precipitation, elevation, aspect, and other factors on the 

Tahoe National Forest.

OSV Use Assumptions for Analysis

Assumptions used for the analysis are based on published literature and a Forest Service hydrologist’s 

professional judgement based on experience. These sources of information framed the issues key 

indicators used for analyzing the environmental consequences of each alternative on watershed 

resources. They provide background information and conclusions regarding the effects of OSVs and 

other factors considered in this analysis, and apply to all alternatives.

Assumption 1 

Snow Plowing and Removal. Snow plowing and removal occurs on paved surfaces in snow parks and 

does not cause soil disturbance, alter existing drainage patterns, or affect soil permeability. It is not part 

of the proposed action, but is an on-going and reasonably foreseeable action that should be considered 

especially for cumulative effects. Snow removal at trailhead parking areas has been occurring for 

decades. BMPs would be applied that ensure that snowmelt from snow storage areas does not result in 

erosion or impair quality of surface waters. The thaw rate in snow storage areas is typically slow, and 

snow is placed where the runoff percolates into the soil. High runoff rates are uncommon from snow 

storage areas. As a result, erosion or siltation from snow storage runoff is minimal. With implementation 

of BMPs, snow removal would not cause significant impacts from erosion. The snow removal 

operations at trailhead parking areas would not result in direct impacts on water quality. Snowmelt from 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

153

snow storage areas could contain a more concentrated level of fuel deposits, oils, sand, and particulates.

Snow is removed in designated storage areas where the snowmelt can percolate into the soil and sheet 

flow across parking areas is avoided; and direct discharge into surface water is avoided. As a result, the 

potential for water quality impacts associated with contaminants in the snow from plow equipment use 

is considered minimal. Snow removal operations are subject to BMPs, which ensure compliance with 

Federal Clean Water Act requirements. Consequently, project activities including snow removal are 

consistent with LRMP watershed management standard and guidelines and management prescriptions. 

Assumption 2

Trail Grooming. Direct project activities of trail grooming occur over an existing road and trail network 

and do not alter landforms or result in significant soil disturbance that would change water flow patterns 

or quantities of surface water runoff. Provided there is adequate snow cover to prevent resource damage, 

trail grooming does not cause substantial impacts to water quality; perennial, intermittent, or ephemeral 

streams; wetlands; or other bodies of water. Consequently, project activities including snow removal, 

trail grooming, and OSV travel on groomed trails are consistent with LRMP watershed management 

standards and guidelines and management prescriptions. 

Assumption 3

OSV Use on trails. Most OSV trails are snow-covered unpaved roads and trails. The primary pollutant 

of concern in forested environments is eroded sediment from unpaved roads, fill slopes, and cut slopes. 

According to West (2002), roads in forested lands are the primary source of possible non-point source of 

pollution. Fine-grained sediment from roads and trails that reaches waterbodies impairs water quality.

Much of the OSV use under this plan would occur on groomed trails where the plan calls for adequate 

snow cover, negligible anticipated contact with bare soil, and minimal disturbance of trail and road 

surfaces. OSV use on the groomed trail system, given adequate snow coverage, would not substantially 

impact water quality in perennial, intermittent or ephemeral streams, and in wetlands or other bodies of 

water.

Assumption 4

Cross-country off-trail riding by OSVs. With adequate snow depths, cross-country use of OSVs 

would have a negligible effect on ground disturbance that could lead to erosion and sedimentation in 

streams or other waterbodies, and minimal effect on vegetation, especially along streams and other 

waterbodies. Some researchers have found that snowmobiles can contribute to erosion of trails and steep 

slopes. The degree of potential erosion is dependent on site-specific factors such as slope, aspect, 

elevation, adjacent vegetation, level of use, and weather conditions. Olliff et al. (1999) found that if 

steep slopes are intensively used, snow may be removed and the ground surface exposed to extreme 

weather conditions and increased erosion by continued snowmobile traffic. Similar results could occur 

when snowmobiles use exposed southern exposures. Public OSV use in off-trail open riding areas where 

there is minimal snow cover or bare patches of ground could possibly result in destruction of vegetation, 

soil compaction, and erosion in areas of repeated and concentrated use.

Off-trail public OSV use would be generally dispersed and would not result in high concentration of 

OSV use on bare soil. Also, travel over bare soil can damage machines, so it is generally avoided by 

operators. With adequate minimum snow levels, this plan would result in no more than incidental soil 
Over-snow Vehicle Use Designation 

Tahoe National Forest

154

erosion, and therefore, would not create water quality impacts to streams or waterbodies by introducing 

sediment in water runoff.

Cross-country OSV use could affect woody riparian species by the bending and breaking of branches as

recreationists run over the branches (Neumann and Merriam 1972). This is most likely to occur with 

lower snow depths, such as the beginning of the winter season, and before sufficient snow has 

accumulated to protect vegetation, and during spring snowmelt. Regenerating timber could also be 

affected by bending and breaking of leaders with inadequate snow depth. Vegetation trampling from 

snowmobiles and impacts to riparian resources from public OSV use would be considered negligible 

with adequate snowpack coverage.

Widespread snow compaction from cross-country OSV uses can affect snowmelt patterns, and in turn,

the hydrologic regime. Studies have found delayed snowmelt in areas compacted by snowmobiles 

versus areas of uncompacted snow (Keddy et al. 1979, Neumann and Merriam 1972). During spring 

snowmelt, these effects can reduce the ability of the snow to slow runoff. It is unknown how much 

OSV-related snow compaction would affect runoff rate and timing, but some studies suggest up to a 2-

week delay. Because snow compaction from off-trail cross-country use is currently not extensive on a 

watershed scale, measureable changes in hydrology are not expected.

When OSVs are operated on adequate snow depths, the effects of plan activities of cross-country OSV 

uses are consistent with the Tahoe National Forest LRMP including Riparian Conservation Objectives 

and watershed management standards and guidelines and management prescriptions.

Assumption 5

Exhaust emissions deposited in the snowpack in the amounts anticipated on the Tahoe National Forest 

from grooming equipment or public OSVs on trails or OSVs travelling cross-country would be 

considered minor and currently do not functionally impair water quality of adjacent waterbodies. In 

addition to exhaust emissions, grooming equipment and OSVs can leave behind unburned fuel, 

lubrication oil, and other compounds on the top layers of snow. Some of the unburned hydrocarbons 

would accumulate on the snow surface and could eventually wash into streams and lakes. This could 

cause localized degradation of water quality.

Concentrations of pollutants from OSVs have been observed in snowmelt runoff (Arnold and Koel 

2006, McDaniel and Zielinska 2014). Discharge from two-stroke snowmobile engines can lead to 

indirect pollutant deposition into the top layer of snow and subsequently into the associated surface and 

ground water (Adams 1975). Hagemann and Van Mouweik (1999) found that there is a potential risk to 

aquatic life from snowmobile emissions, but that the risk could not be quantified because of a current 

lack of water quality data. Adams (1975) showed that high concentrations of lead and hydrocarbons 

were found in pond water adjacent to snowmobile trails during the weeks following ice melt. The study 

also found that juvenile brook trout had increased hydrocarbon intake and reduced stamina, from surface 

water and food chain feeding and hydrocarbon uptake. 

Studies conducted in the Rocky Mountains region provide some indication of the possible effects of 

pollution deposition from public OSV use. The U.S. Geological Survey monitored snowpack throughout 

the northern Rocky Mountains over a period of several years to measure regional water quality trends,

as well as the effect of OSV use. The monitoring showed a relationship between OSV use and pollutant 

deposition in the snowpack, but not more than negligible to minor quantities of OSV-related pollution in 

snowmelt. Detectable vehicle-related pollution in snowmelt was found to be in the range of background 

or near-background levels (Ingersoll et al. 2005 as cited in NPS 2007). A study in Yellowstone National 

Park analyzed snowmelt from four test locations adjacent to roadways and parking lots heavily used by 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

155

OSVs between Yellowstone’s West Entrance at West Yellowstone, Montana, and the Old Faithful visitor 

area. No cross-country OSV use was allowed, and OSVs were concentrated on one main trail in to the 

park. The purpose of the study was to evaluate whether increased snowmobile use within the Park was 

creating increased potential for emissions to enter pristine surface waters. Specific objectives were to (1) 

examine snowmelt runoff for the presence of specific volatile organic compounds (VOCs); (2) 

determine if concentrations of any VOCs exceed safe drinking water criteria; and (3) predict the 

potential for impacts by VOCs on the fauna of streams near roads heavily used by snowmobiles in the 

park. In spring 2003 and 2004, water samples were collected and tested. In situ water quality 

measurements (temperature, dissolved oxygen, pH, specific conductance, and turbidity) were collected; 

all were found within acceptable limits. Five VOCs were detected (benzene, ethylbenzene, m- and pxylene, o-xylene, and toluene). The very low concentrations were found to be below EPA criteria and 

guidelines for the VOCs analyzed and were below levels that would adversely impact aquatic 

ecosystems (Arnold and Koel 2006).

The number of snowmobiles that entered Yellowstone in 2003 and 2004 at the West Yellowstone 

trailhead was 47,799 and 22,423, respectively (Arnold and Koel 2006); all routed through a single 

trailhead. In comparison, the 2009 estimated seasonal day use of OSV trails across the Tahoe National 

Forest was around 20,000 OSVs, spread over 6 trailheads. These visitations were spread across multiple 

trailheads and trail systems and did not all occur in the same location. Use patterns based on 

snowmobile registrations in local counties have remained about the same or slightly increased, and are 

likely to slowly increase in the future. Even with projected increases in OSV seasonal use levels at any 

Tahoe National Forest trailhead or trail system are considerably less than OSV use that occurred at 

Yellowstone National Park during the snowmelt studies, and use at Tahoe National Forest trailheads was 

considered comparatively low. Since Yellowstone OSV use levels studied had not resulted in impaired 

water quality, it follows that lower public OSV use at trailheads is not likely to adversely affect water 

quality of snowmelt. Therefore, due to very low concentrations of pollutants from OSV use such as 

VOCs, operation of public OSVs on system trails and cross-country is consistent with water quality 

objectives in the Tahoe National Forest LRMP including Riparian Conservation Objectives and 

watershed management standards and guidelines and management prescriptions.

Assumption 6

Other hydrology impacts. This plan would (1) not involve the construction of any structures which 

could impede or redirect flood flows, nor any ground surface modifications which could change 

drainage patterns, impervious surfaces, soil permeability, or other hydrological characteristics such as 

surface water volumes; (2) not expose people or property to a risk of flooding nor increase the risk of 

flooding for existing development in floodplains; (3) not place housing or other structures within a flood 

hazard area; (4) not involve a change in water use, affect a private or public water supply, or affect the 

quantity or quality of groundwater recharge, aquifer volume or cause a lowering of the local 

groundwater table level; (5) not involve an increase in impervious surfaces, and (6) not involve 

discharges of storm water or wastewater. 

Assumption 7

The equivalent roaded acre (ERA). This model (FSH 1990a: chapter 20) was not used for this 

analysis to show cumulative watershed effects. 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. As long as adequate snow depths are maintained, because there are virtually no direct or indirect 

effects, using the ERA model will not show any detectable differences between alternatives and is not 
Over-snow Vehicle Use Designation 

Tahoe National Forest

156

appropriate for this scale of analysis, which covers nearly a million acres. The ERA model is beneficial 

at demonstrating changes in ERA for plans that intend to disturb hundreds to thousands of acres for 

fuels reduction, travel management or timber harvest plans, or to show cumulative effects of wildfires.

This plan is not creating a new disturbance on the landscape for any alternative. Changing the overall 

acreage of areas open for OSVs will not lead to increases or decreases in ground disturbance as long as 

OSVs are managed appropriately. Finally, the ERA method would not show any detectable differences 

within the sixth field watersheds in this analysis.

Assumption 8

Global climate change. Climate change is expected to substantially affect California over the next 50 

years (http://www.water.ca.gov/climatechange/docs/062807factsheet.pdf). Precipitation is likely to 

become more variable from year to year. Warmer temperatures will reduce the proportion of 

precipitation that falls as snow and increase the proportion that falls as rain. This shift will result in later 

snowmelt accumulation, earlier snowmelt, higher peak flows, more frequent flooding, increased erosion, 

reduced summer baseflows, more frequent droughts, and increased summertime stream temperatures.

These expected changes have several implications for public OSV use effects on water resources on 

national forests:

• As floods become more frequent and of greater magnitude, roads and trails used for winter-time 

OSV use will likely be subjected to greater stresses from higher runoff. Erosion of route surfaces 

and route/stream crossings will become more common. Ephemeral channels will carry water more 

frequently than in the past.

• The road and trail networks used for winter-time OSV uses will have a role in increasing runoff and

peak flows (Ziemer 1981, Jones and Grant 1996) in the runoff season. Cumulative watershed effects 

in watersheds near their thresholds of concern may become more common.

• Protection and restoration of meadows and other riparian areas that extend the duration of baseflows 

will be increasingly important as snowpack diminishes.

• Seasons of use for OSV routes may need to be modified as precipitation and temperature patterns 

change. 

Assumption 9

Non-motorized uses. For the purposes of this analysis, non-motorized uses have very little to no effect 

on hydrology and will not be considered further in this analysis.

Spatial and Temporal Context for Effects Analysis

The spatial and temporal bounds for discussing and analyzing direct, indirect, and cumulative effects on 

water resources and associated riparian areas and wetlands would be the watersheds within the Tahoe 

National Forest.

Short-term effects are generally around up to one year in duration, and long-term effects are over one 

year in duration.

Affected Environment 

The Tahoe National Forest is subdivided into 53 6th level watersheds. The watershed average size is 

about 32,000 acres. The existing condition of watersheds (watershed health) on the forest varies 

depending upon amount of disturbance found within each watershed and the degree of natural integrity 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

157

of the system. Disturbance in the form of land management activities, such as timber management, road 

construction, livestock grazing, mining, recreation, and special-uses can adversely affect a watershed's 

condition. Past management activities have been concentrated within certain watersheds. Management 

activity effects are influenced in part by the local terrain, the precipitation regime, and other factors.

Table 52. Hydrologic characteristics of the OSV analysis area within Tahoe National Forest

Resource Hydrologic Characteristics

Landscape Sierra Nevada Mountains 

Elevation ranges between 1,040 feet (foothills) and 9,120 feet (Sierra Crest).

Climate Highly variable across Tahoe National Forest due to elevation and orographic elevation effect 

of Sierra Nevada Mountain Range.

Mediterranean climate, whereby most precipitation occurs between November and April.

Winter precipitation below 3,500 feet is primarily rain, mixed rain and snow from 3,500 to 

5,000 feet and above 5,000 feet is primarily snow.

Mean annual precipitation ranges between: 30-40 inches at the Sacramento Valley foothills, 

60-70 inches at the crest of the Sierra Nevada.

Aquatic 

features

1,365 miles of perennial streams.

6,480 miles of intermittent streams.

4,560 lakes with total acreage of 58,171 acres, ranging between <0.01 acres to 6,909 acres.

444 meadows with total acreage of 6,613 acres, ranging between <0.01 acres to 394 acres.

Beneficial 

Uses*

Varies by watershed: municipal water supplies for domestic use, fire protection, hydropower 

generation, irrigation, contact and non-contact recreation, cold freshwater habitat, spawning 

habitat, stock watering, and wildlife habitat. 

Domestic use Truckee River, which supplies water to the community of Reno-Sparks.

Watersheds 53 sixth-field watersheds on the Tahoe National Forest within the affected environment.

Average size of entire watersheds (includes all ownerships): 31,610 acres

Average watershed acreage within affected environment: 2,306 acres

*

Source: Cal EPA CVWQCB 2007 or Source: Cal EPA LWRCB 2006

Surface Water

The Tahoe National Forest 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, south of Bear Creek confluence to the area near the California border near Floriston is within the 

Tahoe National Forest boundary. 
Over-snow Vehicle Use Designation 

Tahoe National Forest

158

Most of the watersheds on the Tahoe National Forest are highly regulated systems. FERC re-licensing is 

in process for the The American, Yuba, and Bear River. 

The hydrology of the plan area is dynamic and evolving. There can be significant annual variations in 

water availability and quality, seasonal flow rates, and water temperatures. Modern human activities 

have altered the natural dynamics of water through the construction of dams and diversions, watershed 

practices that alter water yields, temperature, and sedimentation, and the introduction of pollutants and 

exotic biota. Surface waters on the forest originate as runoff from snowmelt and rainfall. Snowfall is 

generally the greatest contributor to total runoff, while intense rainfall events can cause the largest 

floods. The major runoff season on the forest is from April through June. Snowmelt runoff peaks 

usually occur from late May into June. 

Surface water quality

According to the California Water Plan Update (CA DWR 1998) the Tahoe National Forest is 

encompassed by three major hydrologic regions. One region is on the western side 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).

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 53 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 western side of the forest. The American, Yuba, and Feather River systems appear 

to have similar sediment yields.

Table 53. 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 100

Truckee – Upper Truckee

Squaw Creek

Trout Creek

21

93

12

Yuba – Nonmining

Mining

North Yuba – Bullards Bar

160

3,300

130
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

159

Quality of surface water is affected by the integrity of the fluvial system. Some concerns exist for 

watersheds where watershed impacts have affected water quality and stream channel potential, including 

riparian conditions and streambank stability. These effects are in limited locations, and changes in 

management could improve existing conditions. Water quality on the Tahoe National Forest can be 

impacted by many activities. Most pollutants come from non-point sources, i.e., from diffuse sources 

not concentrated into pipes, drains, flumes, or ditches. Examples include erosion from roads and parking 

areas, and forest roads potentially adding more sediment to streams than any other forest operation.

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. Research has shown that 

90 percent of the sediment that ends up in surface 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.

Uses of OSVs has not been extensively monitored on the Tahoe National Forest. However, a monitoring 

study completed in 2011 (Tahoe National Forest 2011 OHV/OSV Monitoring and Management 

Program: 2011 Monitoring Results) showed no impact to riparian systems or meadows, and suggests 

that OSVs have a low risk to water quality under current use levels and levels of management. 

Monitoring of aquatic resources results are summarized in table 54.

Table 54. Tahoe National Forest 2011 OHV/OSV Monitoring and Management Program: 2011 Monitoring 

Results

Monitoring 

Accomplishments Results Were Objectives and Success 

Criteria Met?

American River RD 

OSV Monitoring of 

Aquatic Resources

Groomed OSV routes along the Foresthill Divide 

were monitored for resource damage during lowsnow conditions over wetlands, riparian areas, and 

streams. No resource damage to aquatic resources 

was observed. An exceptionally deep snow pack in 

winter/spring 2011 contributed to the protection of 

aquatic resources.

Yes, monitoring determined OSV 

use in relation to aquatic 

resources. No effects to aquatic 

resources were identified and no 

management actions are needed.
Over-snow Vehicle Use Designation 

Tahoe National Forest

160

Figure 12. Modelled landscape erosion values by HUC6 watershed (USDA Forest Service 2012). 

Higher erosion risk watersheds have a higher risk of stream sedimentation.

Existing Landscape Erosion/Sedimentation Risk

Many factors can influence the risk of erosion and impacts to watershed resources including: soil 

erosion/sedimentation; 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 roads 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 forest roads indicate that there could be a higher risk of accelerated erosion and sediment production. 

The inherent risk of erosion of the soils and subsequent sediment erosion and water quality impacts 

within the Tahoe National Forest was assessed using two methods: the R-5 soil erosion hazard rating 

(EHR) found in Tahoe National Forest Soil Resource Inventory and the Ecosystem Management 

Decision Support Model. The R-5 EHR ratings indicate that 82 percent of the soils on the Tahoe 

National Forest have a high to very high erosion risk. The model was used to refine the soil erosion risk 

analysis. The modelled erosion risk scores were averaged by HUC6 watershed to assess the motorized 

route related erosion risk at the landscape scale. The landscape erosion risk score were compared 

between 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 erosion risks on the 

Tahoe National Forest. Whereas the North Yuba River, which is much steeper, has more geo-debris 

slides, and more erosive soils, has the highest erosion risks on the Tahoe National Forest (figure 12).
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

161

Table 55. Modelled erosion risk rating by major river basin (USDA Forest Service 2012).

Higher erosion rates can lead to increased risk of stream sedimentation.

River Basin Erosion Risk Class

Middle Truckee River 0.58 (0-25%)

Little Truckee River 0.65 (0-25%)

Subtotal Truckee 0.61 (0-25%)

Feather 0.62 (0-25%)

North Yuba 0.40 (75-100%)

Middle Yuba 0.44 (50-75%)

South Yuba 0.48 (25-50%)

Subtotal Yuba 0.44 (50-75%)

Bear 0.44 (50-75%)

Middle Fork American 0.45 (50-75%)

North Fork American 0.42 (50-75%)

Subtotal American 0.43 (50-75%)

Tahoe National Forest 0.48 (25-50%)

Table 55 shows the average modelled erosion risk rating by major river basin. Erosion risk often 

correlates with increased risk of sedimentation. The erosion risks in the Truckee and Feather River 

basins are the lowest on the Tahoe National Forest. Erosion risk in the Middle Truckee River basin is in 

the lowest erosion risk class. The Bear River basin is in the higher erosion risk. The Yuba River and 

American River basins have similar erosion risks, with the South Yuba having a slightly lower erosion 

risk than the rest of the Yuba River basin. 

Section 305(b) of the Clean Water Act requires states prepare and submit a water quality summary 

report every two years to the Environmental Protection Agency (EPA). In addition, CWA Section 

303(d) requires states to submit to EPA lists of waterbodies that meet 303(d) listing criteria. This list 

identifies water quality-limited waterbodies. Water quality impacts can be from point and/or nonpoint 

sources of pollution, and may require additional controls to meet state water quality standards. These 

waterbodies are prioritized based on the severity of the pollution and other factors. Currently impaired 

waters include six waterbodies on the Tahoe National Forest that are listed as impaired on the EPA’s 

303(d) List. These are the Truckee River (sediment); Kanaka Creek (arsenic), Squaw Creek 

(sedimentation/siltation) and Humbug Creek (lead, sediment, etc.). Table 56 displays the 303(d) listed 

waterbodies and the reason for listing.
Over-snow Vehicle Use Designation 

Tahoe National Forest

162

Table 56. Impaired waterbodies on the Tahoe National Forest 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

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

Source: Cal EPA CVWQCB 2007; Source: Cal EPA LWRCB 2006

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.

Surface Water Uses

Surface water from the forest is used both consumptively and non-consumptively. Uses in both 

categories depend on high quality water. Non-consumptive water uses include recreation, wildlife, 

fisheries, and the aesthetic quality of this resource. Value on the forest is high for these uses. The Tahoe 

National Forest contains no municipal watersheds that are managed under any type of agreement.

However, water generated from the forest is used for municipal supply for some areas, such as the City 

of Reno/Sparks, which uses the Truckee River for municipal water supply.

The Tahoe National Forest 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.

Surface Water Protection Measures

Public water supplies are protected by the Safe Drinking Water Act (SDWA), which was amended in 

1996. The SDWA does not require source areas to deliver water of potable quality with no need for 

treatment. In fact, waters in pristine areas usually need treatment due to natural waterborne parasites, 

such as giardia. 

Best management practices have been adopted to protect water quality in compliance with the Clean 

Water Act. Best management practices cover a wide variety of land management actions on National 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

163

Forest System lands, including watershed management, timber, transportation and facilities, pesticideuse, recreation, minerals, fish and wildlife habitat, and fire suppression and fuels management. When 

best management practices are properly applied, pollutant delivery to streams and lakes is minimal and 

recovery of waters and aquatic sites should be rapid. The physical, chemical, and biological integrity of 

waters in all watersheds should be as good as in watersheds that are managed exclusively for domestic 

and municipal supplies.

Groundwater

Rainfall and snowmelt, as well as producing surface runoff, also recharge groundwater sources on the 

forest. Groundwater aquifers release water during periods of low precipitation to maintain base flows of 

streams. Groundwater is of beneficial use both on and off-forest, in the form of water supply wells. 

Communities use groundwater for part or all of their municipal water supply, while other residents use 

individual domestic wells. Consumptive use of groundwater on the forest is low. Such use is limited to 

special-use permittees and Forest Service campgrounds and administrative sites with domestic wells. 

The existing condition of groundwater on the forest is good, although not all wells provide high quality 

drinking water. Past management activities on the forest do not appear to have adversely affected 

groundwater quality. No groundwater contamination from recreation uses (toilets) has been recorded, 

with all road-accessible toilets being of the pump-vault type. Some potential for such ground water 

contamination exists at heavily used recreation sites with limited facilities.

Riparian Areas and Wetlands

Riparian areas are the transition zone between uplands and water in lakes and rivers. Riparian 

ecosystems are characterized by the presence of trees, shrubs, or herbaceous vegetation that require free 

or unbound water, or conditions that are moister than those of surrounding areas. Riparian ecosystems, 

aquatic ecosystems, wetlands, lakeside zones, and floodplains will be jointly referred to as riparian 

areas. The terms riparian zones and riparian areas are used interchangeably, but by strict ecological 

definition, may not be the same in all instances. Riparian areas occur in stream corridors, along 

lakeshores, and around springs, wetlands, and wet meadows. Vegetation in riparian areas can include 

characteristic woody riparian hardwood types such as aspen, alder, or willow, or it can include larger 

and more vigorous trees of the same species as found on adjacent uplands. 

The forest contains a variety of wetlands. Wetlands are defined in the 1987 Corps of Engineers 

Wetlands Delineation Manual (USDD Army Corps of Engineers 1989) as: “Those areas that are 

inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and 

under normal circumstances do support a prevalence of vegetation typically adapted for life in saturated 

soil conditions. Wetlands generally include swamps, marshes, fens, bogs, and similar areas.”

Riparian ecosystems are generally inclusive of wetlands. Healthy riparian areas, with an abundance of 

trees and other vegetation, slow flood waters and reduce the likelihood of downstream flooding. 

Riparian areas improve water quality by filtering runoff and sediment from flood flows and adjacent 

upland slopes. Healthy riparian areas act like a sponge, absorbing water readily during periods of 

excess. Water slowed by riparian areas enters the groundwater. Some of it is released later, increasing 

late summer and fall streamflow. Riparian areas produce an abundance of stream cover and shade, 

which in turn limit the amount of water temperature fluctuation in the stream. This limiting in water 

temperature is generally advantageous to cold-water fish species. Benefits provided by riparian areas 

include food, cover, and nesting habitat for birds. Many animals visit and live in riparian areas. They 

come for water, food, cover, and temperature moderation. Riparian areas often provide sheltered 

upstream and downstream transportation corridors to other habitats. Fish depend upon healthy riparian 
Over-snow Vehicle Use Designation 

Tahoe National Forest

164

areas to provide stable channels, sustained water supply, clean and cool water, food, and streambank 

cover. 

Riparian areas are attractive and inviting to forest visitors. Public OSVs often use existing roads and 

trails for snowmobile routes. The most serious impacts of roads and motorized trails on the Tahoe 

National Forest occur where they are in close proximity to streams or wetlands within RCAs. Native 

surface roads and motorized trails within RCAs can impact water resources including water quality. 

There are currently 1,054 miles of native surface roads and motorized trails within RCAs. The current 

density of native surface roads and motorized trails in RCAs on the Tahoe National Forest 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.

Environmental Consequences

Minimization Measures common to all action alternatives

Design features and BMPs will be used to minimize damage to watershed resources from the use of 

OSVs for action alternatives. BMP’s described in this DEIS, Volume II, Appendix D will be applied to 

all alternatives. A description of some of these these practices are described below. Additional practices 

will be included in BMP 2-25 (USDA Forest Service R5 FSH 2509.22 - Soil and Water Conservation 

Handbook, 2011) and National Core BMP Rec-7 and Road-10 regarding over-snow vehicle use and 

equipment refueling. The criteria will be applied to the 19 areas on the Tahoe National Forest that may 

be designated for OSV use under this plan.

Groomed Snow Trails:

1. Impacts to watershed resources would be minimized by making spill containment equipment 

available at the facilities where grooming equipment is re-fueled.

2. Impacts to watershed resources would be minimized by designating equipment maintenance and 

refueling sites to ensure that they are located on gentle slopes, on uplands, and outside of RCAs 

and sensitive terrestrial wildlife habitats.

Cross-Country OSV Use:

1. Impacts to watershed resources would be minimized by prohibiting cross-country OSV use 

when and where there is less snow coverage than sufficient to prevent damage to underlying soil 

and vegetation resources. 

2. Impacts to watershed resources would be minimized as a result of allowing for dispersed use in 

open areas. Off-trail OSV use would be generally dispersed and would not result in high 

concentration of OSV use on areas without snow cover. Also, travel over areas without snow 

cover can damage machines, so it is generally avoided by operators. With adequate snow levels, 

this plan would result in no soil erosion, and therefore, would not create water quality impacts 

to streams or waterbodies by introducing sediment in water runoff.

3. Impacts to watershed resources would be minimized by prohibiting OSV use on unfrozen lakes, 

reservoirs, ponds and any other open surface water.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

165

4. Impacts to watershed resources would be minimized by providing information to the public of 

the hazards of running over-snow vehicles on thin ice and the effects of OSV emissions on air 

quality and water quality.

5. Impacts to watershed resources would be minimized by prohibiting OSV use and grooming in 

wetlands unless protected by adequate snow cover. If OSV trails must enter wetlands, impacts 

to watershed resources would be minimized by using bridges or raised prisms with diffuse 

drainage to sustain flow patterns, setting crossing bottoms at natural levels of channel beds and 

wet meadow surfaces, and avoiding actions that may dewater or reduce water budgets in 

wetlands.

6. Impacts to watershed resources would be minimized by adhering to Best Management Practices 

related to Over Snow Vehicle Use from the 2012 USDA Forest Service National Core BMP 

Technical Guide and the 2011 Region 5 Soil and Water Conservation Handbook. 

All Alternatives

Direct, Indirect and Cumulative Effects

Impacts- Projected Water Supply (direct, indirect, cumulative)

None of the action alternatives would increase impacts to water supplies, because this project would not 

affect water quantity in water supply watersheds. 

Projected Water Quality

Four waterbodies on the Tahoe National Forest are listed as impaired on the EPA’s 303(d) List. Table 56

displays the 303(d) listed waterbodies, the reason for listing, and any possible impacts from the 

proposed OSV plan that 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 that could contribute to this contamination. The water 

body is also listed for sedimentation and siltation. 

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 to 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.

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 proposed 

plan alternatives would contribute additional sediment. 

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 in this watershed. No additional sedimentation is expected from OSV use under any alternative.
Over-snow Vehicle Use Designation 

Tahoe National Forest

166

Alternative 1

Direct and Indirect Effects

Incidental direct effects including ground disturbance in low-snow areas may occur under current use.

Snowmobiles and other OSVs have low ground pressure. However, in some instances snowmobile 

tracks have the capacity to break through thinner snowpacks and churn soil, litter or trail surfaces in to 

the snow, and create isolated ruts in the soil or trail surface. Churned soil may get incorporated in runoff 

when snow melts. Much of the current OSV use occurs on groomed trails where the California OffHighway Vehicle Motor Recreation plan (OHVMR) calls for 12 to 18 inches of snow cover before 

grooming can occur, with low possibility of contact with bare soil and practically no disturbance of trail 

and road surfaces.

For public OSV use on trails, currently there is no standard minimum snow depth to protect and mitigate 

effects of OSVs. However, ground disturbance leading to water quality impacts such as stream 

sedimentation in perennial, intermittent or ephemeral streams, in wetlands or other bodies of water have 

been observed although effects may have occurred in areas not monitored. It is likely that for current 

minimum snow levels, current uses have not resulted in more than incidental and isolated direct effects 

such as soil erosion of groomed trail surfaces, and therefore, have not created indirect water quality 

impacts to streams or waterbodies by increasing sediment in water runoff. 

Alternative 1 does not call for a specified snow depth for public OSV cross-country travel. OSV use in 

off-trail open riding areas where there is minimal snow cover or bare patches of ground could result in 

direct effects including destruction of vegetation, soil compaction, and erosion in areas of repeated and 

concentrated use. However, with adequate snow depths, cross-country use of OSVs would have a 

negligible effect on ground disturbance that could lead to erosion and sedimentation in streams or other 

waterbodies, and likely would have a negligible effect on vegetation, especially along streams and other 

waterbodies. Monitoring has demonstrated that under current conditions, alternative 1, destruction of 

vegetation, soil compaction, and resulting erosion from OSV use have not occurred.

Under alternative 1, there likely has been and would continue to be incidental and isolated ground 

contact in areas where OSVs operating cross country would contact the ground surface due to variations 

in snow depths such as on high wind-exposed ridges, and southern-facing slopes. However, off-trail 

OSV use currently is generally dispersed and does not result in high concentration of ground disturbance 

from public OSV use on bare soil. As demonstrated by monitoring information, alternative 1 has not 

resulted in observed water quality impacts to streams or waterbodies from OSV activity-generated 

sediment reaching water runoff.

Cross-country OSV use can directly affect woody riparian species by trampling, including bending and 

breaking of branches by OSVs running over the branches. This could directly affect shade along streams 

by reducing vegetation cover. Direct effects to vegetation probably do occur under alternative 1 in 

isolated areas, but at this time, the effects from OSV use are limited. As a result, vegetation trampling 

from snowmobiles and impacts to riparian resources from OSV use would be considered negligible with 

adequate snowpack coverage, and no direct or indirect changes to vegetation would be expected from 

the no-action alternative. Riparian woody shrub species along streamcourses appear unaffected by direct 

physical trampling from snowmobiles on vegetation. 

The direct effect of widespread snow compaction from cross-country OSV uses can create more dense 

snow that leads to an indirect effect of slower melt rate, and could, in turn, indirectly affect the 

hydrologic regime by delaying snowmelt rates. It is unknown how much OSV-related snow compaction 

would affect runoff rate and timing, but some studies suggest up to a 2-week delay. Because snow 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

167

compaction from off-trail cross-country use is currently not extensive, measureable changes in 

hydrology on a watershed scale are not expected.

Direct and indirect effects from overall numbers of OSVs can be used to gage water quality effects. In 

2009, 20,000 OSV user days per year were estimated to be using Tahoe National Forest trailheads and 

would have access to cross-country use areas. Use numbers have likely gone up a few percent since 

2009. Public OSV users would be spread over 6 trailheads, so actual user numbers will be lower for a 

particular area. Studies on OSV impacts on water quality indicate that even at much higher use levels, 

there would be no adverse effects on water quality from OSV exhaust emissions (Assumption 5). The 

number of snowmobiles that entered Yellowstone in 2003 and 2004 was 47,799 and 22,423,

respectively. At Yellowstone, OSVs were confined to a few trails and use levels were monitored of high 

numbers of OSVs using a single trailhead. Since the much higher Yellowstone OSV use levels studied 

had not resulted in impaired water quality, it follows that the OSV use in the project area for this 

alternative would not likely adversely affect water quality of snowmelt from OSV exhaust emissions.

Activities such as “water skipping” or trying to snowmobile across open water have been observed in 

some areas. These efforts are not always successful resulting in snowmobiles abandoned in lakes or

other open water. This increases effects to water quality from lubricants leaking into surface water,

which can also affect aquatic biota. Similarly, during spring break-up, snowmobiles will cross open 

streams and other waterbodies where snow cover is not present, which results in the deposition of 

pollutants directly in streamcourses and waterbodies. 

Even though there is no specific snow depth standard, the effects of current operation of OSVs occurs 

over a protective layer of snow, and direct and indirect effects to hydrology are isolated and incidental.

For existing minimum snow levels, the plan would not result in more than incidental soil erosion, and 

therefore, would not create water quality impacts to streams or waterbodies by introducing sediment in 

to water runoff. Therefore, with adequate snow depths current OSV use on trails is consistent with the 

Tahoe National Forest LRMP including Riparian Conservation Objectives and watershed management 

standards and guidelines and management prescriptions.

Currently, water quality effects from OSV exhaust stored in snowpack would be negligible and not 

exceed water quality standards. Therefore, as a result, current operation of public OSV use on system 

trails and cross-country is consistent with water quality objectives in the Tahoe National Forest LRMP 

including Riparian Conservation Objectives 1, 2, 4, 5, and 6 and watershed management standard and 

guidelines and management prescriptions.

The riparian conservation objectives apply to all routes that pass through RCAs and meadows. Under 

alternative 1, groomed and ungroomed OSV trails and cross-country travel would be allowed within 

RCAs, but because of the protective layer of snowpack protecting the ground surface, there is currently 

a very low resource damage potential. No restrictions on OSVs in riparian areas, lakes, or meadows are 

currently in place. No adverse impacts to these areas have been observed or monitored. 

RCOs 1 and 6: Under alternative 1, beneficial uses of waterbodies would be protected and enhanced. 

There would be no changes in water storage, seasonal availability, and quality.

RCOs 2, 4, and 5: Under alternative 1, the geomorphic and biological characteristics of meadows, 

streams and RCAs would be protected. No sedimentation would likely result in no changes to aquatic 
Over-snow Vehicle Use Designation 

Tahoe National Forest

168

primary productivity. Growing season water availability would remain unchanged and would not affect 

ecosystem integrity.

Cumulative Effects

Past, present, and reasonably foreseeable projects in the project area are listed in appendix C, and 

include the Truckee River Tribuaries project which is designed to decrease sediment sources in the 

Truckee River Watershed. There are many past, on-going and reasonably foreseeable projects identified 

by the Tahoe National Forest that may be ground-disturbing and could add sediment or other pollutants 

to surface waters within the forest. The Forest Service utilizes best management practices in compliance 

with the Clean Water Act to minimize water quality impacts. The Tahoe National Forest monitors roads 

and trails used for OSVs and implements best management practices to control erosion and other 

effects.

The risks of cumulative effects from this alternative are very low because current snow depths appear to 

be adequate to protect the ground surface. There would continue to be only incidental ground 

disturbance, low risk of damage to vegetation, and other direct and indirect effects. As a result, there 

would be no change to cumulative watershed effects or equivalent roaded acres (ERA) calculations for 

any watersheds under this alternative. There would be negligible effects from exhaust emissions stored 

in snowpack. This alternative would not implement the recommended mitigations, and has the second 

highest amount of land area designated for OSV use. However, this alternative appears to have adequate 

snow cover to protect soils and water resources, and to protect vegetation in riparian areas. This 

alternative would not directly conflict with LRMP standards and guidelines, and would not result in 

irreversible or irretrievable effects to soil, water, or riparian resources.

Alternative 2

Direct and Indirect Effects

The effects of alternative 2 are similar to alternative 1, except for lower number of acres designated for

OSVs, and the snow depth requirement for use of OSV trails. Forest monitoring data has shown that 

under alternative 1, with no minimum snow depth, there has been no observed impacts to aquatic 

systems. It follows then that with a higher snow depth standard under alternative 2 that there would 

continue to be negligible resource effects from trail use and cross-country OSV travel. Under this 

alternative, about 200,000 acres less forest lands are open to public OSV use. Because direct and 

indirect effects of this alternative are negligible, having less acreage designated for OSVs would not 

lead to an increase in direct or indirect effects on hydrology.

As in alternative 1, incidental direct effects including ground and vegetation disturbance in low-snow

areas may occur under this alternative. One substantial difference in this alternative is the recommended 

minimum 6 inches snow depth required for the use on designated trails and a minimum 12 inches snow 

depth for cross-country use. This snow depth is recommended to be either a 6-inch or 12-inch minimum, 

but the snow depth requirement also requires there to be no resource damage. Resource damage created 

by OSVs would be primarily impacts to the trail surface or vegetation that could lead to water quality 

impacts. Because recommended minimum snow levels under alternative 2 are higher than alternative 1

on designated trails, there is a lower risk of ground disturbance and subsequent water quality impacts.

On designated trails with 6 inches of snow cover, snowmobile tracks have a capacity to break through a 

thinner snowpack and churn soil, litter or trail surfaces in to the snow, and create isolated ruts in the trail 

surface. Higher snow amounts may be required to reduce the potential for resource damage. Modern 

OSVs with deep lugs on their treads can easily displace 4 inches of snow each pass, depending on snow 

moisture amounts. Ruts could channel runoff from road or trail surfaces, leading to stream 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

169

sedimentation. Churned soil may get incorporated in runoff when snow melts. Currently, there are no 

studies or monitoring information that can provide information on direct or indirect effects of the 

recommended 6 inches snow depth on trails proposed for this alternative. However, snowmobile user 

web forums usually suggest about 6 inches as a minimum snow amount needed before snowmobile use 

(http://www.snowmobileforum.com/general-sled-chat/25036-whats-minimum-amount-snow-youshould.html). Snowmobilers hesitate to operate machines on soil because it would damage machinery.

The 6-inch snow depth may or may not be an adequate depth for hydrology resource protection because 

direct effects of operation of OSVs on 6 inches of snow on trails may lead to possible trail surface 

displacement and rutting, leading to a slight chance of sediment erosion from the trail surface. Further, 

this 6-inch snow depth may be sufficient for operation of a snowmobile, but other OSVs may need more 

depth to avoid ground disturbance. This alternative requires that snowpack should be sufficient to 

prevent resource damage. Monitoring of trail surfaces and vegetation and feedback to trail managers 

would be needed to ensure that resource damage is not occurring and that this standard is met.

For this alternative, as a result of a minimum 6-inch snow depth on trails there likely is a higher risk of 

causing direct trail impacts such as displacement of the trail surface compared to having a 12-inch

minimum snow depth for trail uses. A 6-inch snow depth can become much thinner and may not offer 

effective protection for the ground surface after several passes by OSVs. Overall however, OSV use in 

alternative 2 would occur over a protective layer of snow designed to avoid resource damage, and direct 

and indirect effects to hydrology would likely be isolated and incidental. As a result, for proposed 

minimum snow levels, alternative 2 would likely not result in more than incidental soil erosion and 

therefore would not create indirect water quality impacts to streams or waterbodies by introducing 

sediment in to water runoff. With adequate snow depths, OSV use on trails is consistent with the Tahoe 

National Forest LRMP including Riparian Conservation Objectives and watershed management 

standards and guidelines and management prescriptions.

As in alternative 1, much of the OSV use under this alternative would occur on OHVMR groomed trails 

where the plan calls for 12 to 18 of snow cover before grooming can occur, negligible possibility of 

contact with bare soil, and practically no disturbance of trail and road surfaces. For OSV use on the 

groomed OSV trail system, the minimum snow depth standard snow coverage would be adequate to 

mitigate and eliminate substantial indirect water quality impacts such as stream sedimentation in 

perennial, intermittent or ephemeral streams, in wetlands or other bodies of water.

Because vehicles would be dispersed, a proposed recommended 12-inch minimum snow depth for 

cross-country use would not result in more than incidental and isolated direct effects such as ground 

contact and disturbance to vegetation. Again this standard would require avoidance of resource damage, 

and would require deeper snowpack if resource damage is occurring. It is not anticipated that indirect 

water quality impacts to streams or waterbodies by increasing sediment in water runoff would occur as a 

result of cross-country use of OSVs under this alternative. There would continue to be incidental and 

isolated ground contact in areas where OSVs operating cross country would contact the ground surface 

due to variations in snow depths such as on high wind-exposed ridges, and southern-facing slopes. Offtrail OSV use would be generally dispersed and would not result in a high concentration of ground 

disturbance from OSV use on bare soil. With adequate minimum snow levels, current conditions would 

result in no more than incidental surface disturbance and soil erosion, and therefore, would not create 

water quality impacts to streams or waterbodies by introducing sediment to water runoff.

Similar to alternative 1, cross-country OSV use could directly affect woody riparian species by 

trampling, including bending and breaking of branches by OSVs running over vegetation. This could

directly affect shade along streams by reducing vegetation cover. Direct effects to vegetation probably 
Over-snow Vehicle Use Designation 

Tahoe National Forest

170

would occur under alternative 2, but the effects would be limited by requiring adequate snow cover 

before allowing OSV use. As a result, vegetation trampling from snowmobiles and impacts to riparian 

resources from OSV use would be considered negligible with adequate snowpack coverage, and no 

direct or indirect changes to vegetation would be expected from this alternative. Riparian woody shrub 

species along stream courses would continue to be protected by the 12 inch snow cover no resource 

damage requirement by limiting the direct physical trampling effect from snowmobiles on vegetation.

The direct effect of widespread snow compaction from cross-country OSV uses under alternative 2 

would create denser snow that could lead to an indirect effect of slower snowmelt rates, and could in 

turn indirectly affect the hydrologic regime by delaying snowmelt rates in localized areas. It is unknown 

how much OSV-related snow compaction would affect runoff rates and timing, and some studies 

suggest up to a 2-week delay in melting for heavily compacted snow such as on groomed OSV trails. It 

is not expected that snowmobile cross-country uses would heavily compact snow over large areas.

Because the areal extent of snow compaction from off-trail cross-country use combined with compacted 

snow on groomed trails would not be extensive on a watershed scale, measureable changes in hydrology 

are not expected.

As described in the assumptions for this plan, water quality effects from OSV exhaust hydrocarbon 

emissions stored in snowpacks under alternative 2 would be negligible and would not be expected to 

exceed water quality standards.

Under alternative 2, operation of OSVs on system trails and cross-country is consistent with water 

quality objectives in the Tahoe National Forest LRMP including Riparian Conservation Objectives 1, 2, 

4, 5, and 6 and watershed management standards and guidelines and management prescriptions.

The riparian conservation objectives apply to all routes that pass through RCAs and meadows. Under 

alternative 2, groomed and ungroomed OSV trails and cross-country travel would be allowed within 

RCAs, but because of the protective layer of snowpack protecting the ground surface, there is currently 

a negligible resource damage potential. No restrictions on OSVs in riparian areas, or meadows are 

currently in place. No adverse impacts to these areas have been observed or monitored. 

RCOs 1 and 6: Under alternative 2, beneficial uses of waterbodies would be protected and enhanced. 

There would be no changes in water storage, seasonal availability, and quality.

RCOs 2, 4, and 5: Under alternative 2, the geomorphic and biological characteristics of meadows, 

streams and RCAs would be protected. No sedimentation would likely result in no changes to aquatic 

primary productivity. Growing season water availability would remain unchanged and would not affect 

ecosystem integrity.

Cumulative Effects

The Tahoe National Forest utilizes best management practices in compliance with the Clean Water Act 

to minimize water quality impacts. Projects whose best management practices monitoring results are not 

effective are addressed and improved.

Because there is a low risk of direct and indirect effects, the risks of cumulative effects from this 

alternative are negligible. As a result of the 12-inch minimum snow depth/avoid resource damage 

standard for cross-country use and the 6-inch recommended minimum snow depth/avoid resource 

damage trail standard there would continue to be only incidental ground disturbance. As a result, there 

would be no change to equivalent roaded acres (ERA) calculations for any watersheds under this 

alternative, and no change in detrimental cumulative watershed effects. There would be negligible 

effects from exhaust emissions stored in snowpack, low risk of damage to vegetation, and other direct 

and indirect effects. This alternative would implement the recommended project design criteria, or 

mitigation measures. This alternative would have adequate snow cover to protect soils and water 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

171

resources to prevent resource damage, and to protect vegetation in riparian areas. This alternative would 

not directly conflict with Forest Plan standards and guidelines, and would not result in irreversible or 

irretrievable effects to soil, water, or riparian resources.

Alternative 3

Direct and Indirect Effects

Alternative 3 will be compared to alternative 2 because alternative 2 has a minimum snow depth. This 

alternative would have about 131,000 acres less area designated for OSVs compared to alternative 2. 

The implementation of alternative 3 would have similar direct and indirect effects to alternative 2 in 

terms of effects to hydrology. 

Because minimum snow depths are higher under alternative 3, there is more protection of ground 

surfaces during the OSV riding season, and during marginal snow depth conditions such as at the 

beginning and end of the riding season. As in alternative 2, incidental direct effects including ground 

disturbance in low-snow areas may occur under this alternative. However, for proposed minimum snow 

levels, alternative 3 would not result in more than incidental ground disturbance or vegetation trampling 

and would not be likely to create water quality impacts to streams or waterbodies by introducing 

sediment in to water runoff.

The riparian conservation objectives apply to all routes that pass through RCAs and meadows. Under 

alternative 3, groomed and ungroomed OSV trails and cross-country travel would be allowed within 

RCAs, but because of the protective layer of snowpack protecting the ground surface there is currently a 

negligible resource damage potential. No restrictions on public OSV operations in riparian areas, lakes 

or meadows are currently in place or are prescribed for this alternative. No adverse impacts to these 

areas have been observed or monitored. 

RCOs 1 and 6: Under alternative 3, beneficial uses of waterbodies would be protected and enhanced. 

There would be no changes in water storage, seasonal availability, and quality.

RCOs 2, 4, and 5: Under alternative 3, the geomorphic and biological characteristics of meadows, 

streams and RCAs would be protected. No sedimentation would likely result in no changes to aquatic 

primary productivity. Growing season water availability would remain unchanged and would not affect 

ecosystem integrity. 

Cumulative Effects 

The risks of cumulative effects from this alternative are negligible. As a result of the 18-inch minimum 

snow depth for cross-country use, there would continue to be only incidental ground disturbance. As a 

result, there would be no change to equivalent roaded acres (ERA) calculations for any watersheds 

under this alternative, and no change in detrimental cumulative watershed effects. There would be 

negligible effects from exhaust emissions stored in snowpack, low risk of damage to vegetation, and 

other direct and indirect effects. This alternative would implement the recommended project design 

criteria, or mitigation measures, and has the lowest amount of land area designated for OSVs. This 

alternative has adequate snow cover to protect soils and water resources, and to protect vegetation in 

riparian areas. This alternative would not directly conflict with Forest Plan standards and guidelines.

This alternative would not result in irreversible or irretrievable effects to soil, water, or riparian 

resources.
Over-snow Vehicle Use Designation 

Tahoe National Forest

172

Alternative 4

Direct and Indirect Effects

There would be the same number of acres open to OSVs under alternative 4 as in alternative 1. 

Alternative 4 would provide approximately the same protection for the ground surface as in alternative 

2. The end result of implementation of alternative 4 would be similar to alternative 2 because snow 

levels prescribed in alternative 2 are similar, leading to low risks of direct or indirect effects to 

hydrology. Risks of resource damage created by OSVs would be primarily impacts to the trail surface or 

vegetation that could lead to water quality impacts. 

Implementation of alternative 4 would have similar direct and indirect effects to alternative 2 in terms of 

effects to hydrology. However, minimum snow depths in alternative 2 are recommendations only, with a 

focus on avoiding resource damage. As a result, minimum snow depths under alternative 2 may in fact 

be deeper than the recommended minimum to protect resources and avoid damage. Alternative 4 differs 

from alternative 2 because alternative 2 minimum snow depths could be higher (or less) than alternative 

4. 

Alternative 4 for most conditions would provide protection of ground surfaces, with about the same risk 

for ground disturbance as in alternative 2. Like alternative 2, alternative 4 provides a minimum 

snowpack standard compared to current conditions that will likely functionally avoid direct or indirect 

effects and resource damage from public OSV use. As a result of implementation, direct and indirect 

effects of this alternative on hydrology in areas designated for OSV use s would be negligible. As in 

alternative 2, incidental direct effects including ground disturbance in low-snow areas may occur under 

this alternative. However, for proposed minimum snow levels, alternative 4 would likely not result in 

more than incidental ground disturbance or vegetation trampling and would not likely to create water 

quality impacts to streams or waterbodies by introducing sediment to water runoff.

The riparian conservation objectives apply to all routes that pass through RCAs and meadows. Under 

alternative 4, groomed and ungroomed OSV trails and cross-country travel would be allowed within 

RCAs, but because of the protective layer of snowpack protecting the ground surface, there is currently 

a very low resource damage potential. No restrictions on OSVs in riparian areas, or meadows are 

currently in place. No adverse impacts to these areas have been observed or monitored. 

RCOs 1 and 6: Under alternative 4, beneficial uses of waterbodies would be protected and enhanced. 

There would be no changes in water storage, seasonal availability, and quality.

RCOs 2, 4, and 5: Under alternative 4, the geomorphic and biological characteristics of meadows, 

streams and RCAs would be protected. No sedimentation would likely result in no changes to aquatic 

primary productivity. Growing season water availability would remain unchanged and would not affect 

ecosystem integrity. 

Cumulative Effects 

The risks of cumulative effects from this alternative are negligible. As a result of the 12-inch minimum 

snow depth for cross-country use there would continue to be only incidental ground disturbance. As a 

result, there would be no change to equivalent roaded acres (ERA) calculations for watersheds under 

this alternative, and no change in detrimental cumulative watershed effects. There would be negligible 

effects from exhaust emissions stored in snowpack, low risk of damage to vegetation, and other direct 

and indirect effects. This alternative would implement the recommended project design criteria, or 

mitigation measures, and has nearly the highest amount of land area open to OSVs. This alternative has 

adequate snow cover to protect soils and water resources, and to protect vegetation in riparian areas.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

173

This alternative would not directly conflict with Forest Plan standards and guidelines. This alternative 

would not result in irreversible or irretrievable effects to soil, water, or riparian resources.

Alternative 5

Direct and Indirect Effects

Implementation of alternative 5 would have effects similar to alternative 2 in terms of overall effects and 

risks to hydrology. However, alternative 5 would provide more protection than alternative 2 for ground 

surfaces and vegetation, especially in situations where snow depth conditions in alternative 2 are near 

the minimum depths prescribed for that alternative. The end result of implementation of alternative 5 is 

there would be low risks of direct or indirect effects to hydrology. Resource damage created by OSVs 

where they occur would be primarily impacts to the trail surface or vegetation that could lead to water 

quality impacts. 

Alternative 5 would provide higher levels of protection for the ground surface compared to alternative 2. 

The end result of implementation of alternative 5 would lead to low risks of direct or indirect effects to 

hydrology.

The direct and indirect effects of alternative 5 would be lower than alternative 2. However, like 

alternative 2, alternative 5 provides a minimum snowpack standard compared to current conditions that 

would likely avoid direct or indirect effects and resource damage from OSV use. As a result of 

implementation of this alternative, direct and indirect effects on hydrology in areas designated for OSV 

use would be negligible. As in alternative 2, incidental direct effects including ground disturbance in 

low-snow areas may occur under this alternative. However, for proposed minimum snow levels, and 

decreased area of OSV use, alternative 5 would likely not result in more than incidental ground 

disturbance or vegetation trampling and would not likely to create water quality impacts to streams or 

waterbodies by introducing sediment in to water runoff.

The riparian conservation objectives apply to all routes that pass through RCAs and meadows. Under 

alternative 5, groomed and ungroomed OSV trails and cross-country travel would be allowed within 

RCAs, but because of the protective layer of snowpack protecting the ground surface, there is currently 

a very low resource damage potential. No restrictions on OSVs in riparian areas, or meadows are 

currently in place. No adverse impacts to these areas have been observed or monitored. 

RCOs 1 and 6: Under alternative 5, beneficial uses of waterbodies would be protected and enhanced. 

There would be no changes in water storage, seasonal availability, and quality.

RCOs 2, 4, and 5: Under alternative 5, the geomorphic and biological characteristics of meadows, 

streams and RCAs would be protected. No sedimentation would likely result in no changes to aquatic 

primary productivity. Growing season water availability would remain unchanged and would not affect 

ecosystem integrity. 

Cumulative Effects

The risks of cumulative effects from this alternative are negligible. As a result of the 24-inch minimum 

snow depth for cross-country use, there would continue to be only incidental ground disturbance. As a 

result, there would be no change to equivalent roaded acres (ERA) calculations for watersheds under 

this alternative, and no change in detrimental cumulative watershed effects. There would be negligible 

effects from exhaust emissions stored in snowpack, low risk of damage to vegetation, and other direct 

and indirect effects. This alternative has adequate snow cover to protect soils and water resources, and 
Over-snow Vehicle Use Designation 

Tahoe National Forest

174

to protect vegetation in riparian areas. This alternative would not directly conflict with Forest Plan 

standards and guidelines. This alternative would not result in irreversible or irretrievable effects to soil, 

water, or riparian resources.

Conclusions

Alternative 1 appears to protect water resources, but with the lowest level of protection:

OSV use on trails and cross-country has been observed to be adequate to mitigate and eliminate 

substantial water quality impacts such as stream sedimentation in perennial, intermittent or ephemeral 

streams, in wetlands or other bodies of water. This alternative would have a negligible impact on water 

quality as a result of hydrocarbon emissions from OSVs. Alternative 1 would be consistent with the 

Clean Water Act and Porter Cologne Water Act as water quality would not be impaired and beneficial 

uses would be protected. 

There would be no watersheds with a risk of cumulative watershed effects as result of this alternative, 

and would be consistent with all of the applicable RCOs in the 2004 Sierra Nevada Forest Plan 

Amendment. Beneficial uses of water would be protected.

Alternatives 2 and 4 would protect water resources:

The 6-inch minimum on trails and 12-inch cross-country snow depth standard is adequate to mitigate 

and eliminate substantial water quality impacts such as stream sedimentation in perennial, intermittent 

or ephemeral streams, in wetlands or other bodies of water. However, consistent and timely monitoring 

is needed as a mitigation to ensure that damage to trails would not occur. These alternatives would have 

a negligible impact on water quality as a result of hydrocarbon emissions from OSVs. Beneficial uses of 

waterbodies would be protected under these alternatives, as only 6 inches of snow would be required for 

use of designated OSV trails. As a result, alternatives 2 and 4 would be consistent with the Clean Water 

Act and Porter Cologne Water Act, as water quality and beneficial uses would be protected. There would 

be no watersheds with a risk of cumulative watershed effects as result of these alternatives, and it would 

be consistent with applicable RCOs in the 2004 Sierra Nevada Forest Plan Amendment. 

Alternatives 3 and 5 would best protect water resources:

The 18-inch-minimum snow depth on trails and cross-country is adequate to mitigate and eliminate 

substantial water quality impacts such as stream sedimentation in perennial, intermittent or ephemeral 

streams, in wetlands or other bodies of water. However, consistent and timely monitoring is 

recommended as a mitigation to ensure that damage to trails is not occurring. These alternatives would 

have a negligible impact on water quality as a result of hydrocarbon emissions from OSVs. Beneficial 

uses of waterbodies are protected under these alternatives, as 18 inches or more of snow would be 

required for use of designated OSV trails. As a result, alternatives 2 and 4 would be consistent with the 

Clean Water Act and Porter Cologne Water Act, as water quality and beneficial uses would be 

protected. There would be no watersheds with a risk of cumulative watershed effects as result of these 

alternatives, and it would be consistent with applicable RCOs in the 2004 Sierra Nevada Forest Plan 

Amendment. 

Riparian Conservation Objectives Analysis

The Sierra Nevada Forest Plan Amendment (SNFPA FSEIS ROD) requires that RCO analysis be 

conducted during environmental analysis for new proposed management activities within CAR‘s and 

RCA‘s (Standard and Guideline #92). Consistency with the RCOs is an indicator to ensure that goals of 

the Aquatic Management Strategy are met (USDA FS PSW Region 2004: 32). For this plan allowing 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

175

use of over-snow vehicles when the ground is covered with a protective layer of snow would have a 

negligible effect on RCAs because direct and indirect effects would be negligible, and OSV use would 

result in negligible effects to RCAs. Hydrocarbon pollution derived from OSVs and grooming 

equipment would have a negligible effect on water quality under this plan.

The above determinations are based on Standard and Guideline #92, which states “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.” Consequently, consistency with the RCOs is an indicator to ensure that goals of the Aquatic 

Management Strategy are met (USDA FS PSW Regulation 2004: 32).

Table 57. Riparian conservation areas (RCAs) adjacent to aquatic features as designated by the Sierra

Nevada Forest Plan Amendment Record of Decision (SNFP ROD 2004)

Aquatic feature Riparian Conservation Area

Perennial stream. 300 feet on each side of the stream, measured from the

bank full edge of the stream.

Seasonally flowing streams. 150 feet on each side of the stream, measured from the

bank full edge of the stream.

Special aquatic features (includes lakes, wet

meadows, bogs, fens, wetlands, vernal pools, and

springs).

300 feet from the edge of the features or riparian

vegetation, whichever width is greater.

Perennial streams with riparian conditions extending

more than 150 feet from the edge of the stream

bank or seasonally flow streams extending more

than 50 feet from the edge of the stream bank.

300 feet from the edge of the features or riparian

vegetation, whichever width is greater.

Streams in inner gorge. Top of inner gorge. (The inner gorge is defined by

stream adjacent slopes greater than 70 percent gradient.)

Indicator: Consistency with Riparian Conservation Objectives 1, 2, 4 and 5 (Alternative 1)

The riparian conservation objectives apply to all OSV routes and cross-country use that passes through 

RCAs and meadows. Cross-country OSV routes would traverse meadows and streams with no 

restriction, and OSV trails in some areas are located in RCAs. 

RCO 1: Under alternative 1, beneficial uses of waterbodies are protected. OSV uses do not impact 

beneficial uses of waterbodies, especially municipal watersheds. Beneficial uses within the major 

hydrologic areas, units, or creeks on the Tahoe National Forest, designated by the State Central Valley 

and Lahontan Regional Water Quality Control Boards, have been identified in table 58. OSV uses do not 

impact CWA 303 (d) waterbodies. 

RCO 2: Under alternative 1, the geomorphic and biological characteristics of meadows, perennial 

streams and RCAs are protected under this plan. Under this RCO the goal is to maintain or restore: 

(1) the geomorphic and biological characteristics of special aquatic features, including lakes, meadows, 

bogs, fens, wetlands, vernal pools, springs; (2) streams, including in stream flows; and (3) hydrologic 

connectivity both within and between watersheds to provide for the habitat needs of aquatic-dependent 

species. For this plan, criteria for establishing consistency are that OSV use would not cause accelerated 

erosion, such as head-cutting or the formation of gullies in meadows or spring ecosystems. Current OSV 
Over-snow Vehicle Use Designation 

Tahoe National Forest

176

use does not lower water tables of meadows, does not alter the movement of surface water in meadows. 

OSV use does not de-water spring ecosystems, does not capture streams and divert them down roads, 

and OSV use does not disturb shorelines of natural and man-made lakes and ponds.

RCO 4: Under alternative 1, management activities within RCAs would enhance or maintain physical 

and biological characteristics associated with aquatic- and riparian-dependent species. For this plan, 

criteria for establishing consistency are that OSV use does not degrade the water quality of 

hydrologically connected systems, and that OSV use does not modify channel morphology of streams.

RCO 5: Under alternative 1, efforts would be made to preserve, restore, or enhance special aquatic 

features, such as meadows, lakes, ponds, bogs, fens, and wetlands, to provide the ecological conditions 

and processes needed to recover or enhance the viability of species that rely on these areas

Indicator: Consistency with Riparian Conservation Objectives 1, 2, 4 and 5 (Alternatives 2, 3, 

4, and 5)

The riparian conservation objectives apply to all routes that pass through RCAs and meadows. Crosscountry OSV routes would traverse meadows and streams with no restriction. Snow cover would protect 

these resources, and OSV trails in some areas would be located in RCAs. 

RCO 1: Under alternatives 2, 3, 4, and 5, beneficial uses of waterbodies would be protected. OSV uses 

would not impact beneficial uses of waterbodies, especially municipal watersheds. These alternatives 

would comply with the Clean Water Act. Beneficial uses within the major hydrologic areas, units, or 

creeks on the Tahoe National Forest, designated by the State Lahontan Regional Water Quality Control 

Board and Central Valley Regional Water Quality Control Board, have been identified in table 58. OSV 

uses do not impact CWA 303 (d) waterbodies. 

RCO 2: Under alternatives 2, 3, 4, and 5, the geomorphic and biological characteristics of meadows, 

perennial streams and RCAs would be protected under this plan. Under this RCO, the goal is to maintain 

or restore: (1) the geomorphic and biological characteristics of special aquatic features, including lakes, 

meadows, bogs, fens, wetlands, vernal pools, springs; (2) streams, including in stream flows; and 

(3) hydrologic connectivity both within and between watersheds to provide for the habitat needs of 

aquatic-dependent species. For this plan, criteria for establishing consistency are that OSV use would 

not cause accelerated erosion, such as head-cutting or the formation of gullies in meadows or spring 

ecosystems. Current OSV use does not lower water tables of meadows, does not alter the movement of 

surface water in meadows. OSV use does not de-water spring ecosystems, does not capture streams and 

divert them down roads, and OSV use does not disturb shorelines of natural and human-made lakes and 

ponds.

RCO 4: Under alternatives 2, 3, 4, and 5, management activities within RCAs would enhance or 

maintain physical and biological characteristics associated with aquatic- and riparian-dependent species.

For this plan, criteria for establishing consistency are that OSV use does not degrade the water quality of 

hydrologically connected systems, and that OSV use does not modify channel morphology of streams.

RCO 5: Under alternatives 2, 3, 4, and 5, efforts would be made to preserve, restore, or enhance special 

aquatic features, such as meadows, lakes, ponds, bogs, fens, and wetlands, to provide the ecological 

conditions and processes needed to recover or enhance the viability of species that rely on these areas.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

177

Table 58. Compliance with beneficial uses of water on the Tahoe National Forest Hydrologic Unit/Watershed State HUC no. Municipal and Domestic Supply Agricultural Supply Industrial Process Supply Industrial Service Supply Ground Water Recharge Freshwater Replenishment Navigation Hydropower Generation Water Contact Recreation Non-contact Water Recreation

Commercial and Sport FishingAquacultureWarm Freshwater HabitatCold Freshwater HabitatInland Saline Water HabitatWildlife HabitatSpawning, Reproduction and DevelopmentWater Quality EnhancementFlood Peak Attenuation/Flood Water StoragePreservation of Biological Habitats of Special SignificanceMigration of Aquatic OrganismsRare, threatened and Endangered Species

Truckee River 635.20 x x x x x x x x x x x x x x x x

1Humbug Creek 517 x x x x x x x x x x

1Kanaka Creek 517 x x x x x x x x x x x

Donner Lake 635.20 x x x x x x x x x

Stampede Res. 635.20 x x x x x x x x

Squaw Creek 635.20 x x x x x x x x x x x

1 Cal LRWQCB EPA 1995
Over-snow Vehicle Use Designation

Tahoe National Forest

178

Table 59. Water quality standards of concern for OSVs

Category Standard Beneficial Uses 

Potentially Affected

Floating

Material

Water shall not contain floating material in amounts that cause

nuisance or adversely affect beneficial uses.

Domestic or municipal

Contact Recreation

Non-contact

Recreation Power

Oil and Grease Waters shall not contain oils, greases, waxes, or other materials

that causes nuisance, a visible film or coating on the surface or

on objects in water, or otherwise adversely affect beneficial uses.

All

Total

Dissolved

Solids

Shall not exceed 125 mg/l (90 percentile). Domestic or municipal

Contact Recreation

Aquatic organisms

Sediment The suspended sediment load and discharge rate of surface

waters shall not be altered in such a manner as to cause

nuisance or adversely affect beneficial uses.

All

Settleable

Materials

Waters shall not contain substances in concentrations that result

in the deposition of material that causes nuisance or adversely

affects beneficial uses.

Domestic or municipal

Power

Aquatic organisms

Suspended

Material

Waters shall not contain suspended material in concentrations

that cause nuisance or adversely affect beneficial uses.

All

Turbidity

Waters shall be free of changes in turbidity that cause nuisance

or adversely affect beneficial uses. Increases in turbidity shall not

exceed the following Nephelometric Turbidity Units (NTU)s:

For natural turbidity between: Increases shall not 

exceed

0 and 5 NTUs 1 NTU

5 and 50 NTUs 20 percent

50 and 100 NTUs 10 NTUs

Greater than 100 NTUs 10 percent.

All
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

179

Compliance with Relevant Laws, Regulations, Policies and Plans 

This project is consistent with the Tahoe National Forest LRMP, which provides standards and 

guidelines for water-related concerns. The 2004 Sierra Nevada Forest Plan Amendment modified the 

forest plan guidance.

All alternatives would be consistent with the Clean Water Act and Porter Cologne Water Act as 

water quality and beneficial uses would be protected. Alternatives would be consistent with all 

applicable RCOs in the Sierra Nevada Forest Plan Amendment once mitigation measures have been 

implemented. Beneficial uses of waterbodies and water quality are protected for all alternatives. 

Physical and biological properties of RCAs would be protected for all alternatives.

All alternatives are consistent with the 2004 Sierra Nevada Forest Plan Amendment. The riparian 

conservation objectives apply to all routes that pass through RCAs and meadows. Under all 

alternatives, groomed and un-groomed OSV trails and cross-country travel would be allowed within 

RCAs, but because of the protective layer of snowpack protecting the ground surface, there is 

currently a very low resource damage potential. No restrictions on OSVs in riparian areas, on frozen 

lakes or meadows are currently in place. No adverse impacts to these areas have been observed or 

monitored. 

RCOs 1 and 6: Under all alternatives, beneficial uses of waterbodies would be protected and 

enhanced. There would be no changes in water storage, seasonal availability, and quality.

RCOs 2, 4, and 5: Under all alternatives, the geomorphic and biological characteristics of 

meadows, streams and RCAs would be protected. No sedimentation would likely result in no 

changes to aquatic primary productivity. Growing season water availability would remain unchanged 

and would not affect ecosystem integrity.

This project would comply with the Clean Water Act as enforced through the Porter-Cologne WaterQuality Act for the State of California.

Short-term Uses and Long-term Productivity 

There would be no impacts from short-term uses and long term productivity on hydrologic resources.

Unavoidable Adverse Effects 

There would be no unavoidable adverse effects from the effects of any alternative.

Irreversible and Irretrievable Commitments of Resources

There would be no irreversible or irretrievable commitment of resources for any alternatives.

Soils

Relevant Laws, Regulations, and Policy

Regulatory Framework

Land and Resource Management Plan

The Tahoe National Forest LRMP provides standards and guidelines for activities on the forest 

including OSV management. 
Over-snow Vehicle Use Designation

Tahoe National Forest

180

♦ LRMP Standards and Guidelines pertinent to OSV management (USDA Forest Service 

1990: Chapter 4):

o Maintain or improve long term soil productivity on at least 85 percent of an activity 

area. Soil productivity includes three soil characteristics including soil porosity, soil 

cover and soil organic matter.

 Soil Porosity: The soil is considered to be in an acceptable condition when 

compaction or puddling reduce total soil porosity by no more than 10 

percent as compared to the undisturbed soil.

 Soil Cover: The soil is considered to be in acceptable condition after a landdisturbing activity when the effective soil cover on an activity area is (1) the 

minimum amount shown in the following table, or (2) the minimum amount 

prescribed for a specific site by a qualified earth science specialist after an 

on-site investigation. The minimum effective soil cover prescribed for a 

specific site will vary from the values shown in the table due to local 

differences in slope, micro relief, surface rock fragments, detachability, and 

other factors that vary within soil types.

Minimum effective soil cover (percent) by slope group and soil group (LRMP Page V.37)

Slope (%) < 35 35 to 50 >50

Soil Group A 70 80 90

Soil Group B 50 60 75

Soil Group C 40 50 65

Soil Group D 30 40 55

• Soil Group A: These soils are highly erodible, have developed from granitic parent material, 

have a short timber rotation length, and are at lower elevations on the west side of the Forest. 

Included are the Hoda. Holland, Hotaw, and Musick series.

• Soil Group B: These soils have developed from a variety of parent materials. These soils 

erodibility, geographic location, and climate varies, and they have short to moderate timber 

rotation lengths. Included are the Alken, Boomer, Boomer Variant, Chalx, Cohasset, 

Delieker, Dubakella, Euer, Euer Variant, Forbes, Fugawee, Horseshoe. Hotaw Variant, 

Huysink, Jocal, JocalVariant, Jorge, Kinkel Variant, Lorack Variant, Mariposa. McCarthy. 

Ponto Variant, Putt, Sattley, Slerraville, Sltes, and Trojan series.

• Soil Group C: These soils have developed from a variety of parent materials. The erodibility, 

geographic location, and climate varies across these soil types, and they have moderate to 

long timber rotation lengths. Included are the Aspen Variant, Bucking Variant, Chaix 

Variant. Crozier, Haypress, Hurlbut, Jorge Variant Kyburz, Ledford, Ledford Variant, Neer, 

Smokey. Tahoma Variant, Tallac, Tinker, and Zeibright series.

• Soil Group D: These soils occur primarily in the true fir zone, have low erodibilities and 

have long timber rotations. Included are the Ahart, Bucking, Ceiio Variant, Lorack, Smokey 

Variant, Tahoma, Umpa, Waca, and Windy series.

 Soil Organic Matter:

• Maintain an average of 5 logs per acre
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

181

• Maintain forest duff over 80 percent of an activity area

Regional Direction

Pacific Southwest Region Soil Management Handbook Supplement (Pacific Southwest 

Region FSH Supplement No. 2509.18-95-1)

This supplement establishes regional soil quality analysis standards. The 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 

are to be used for areas 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 of 

routes authorized for travel by OSVs. This standard does apply to cross-country OSV travel.

Federal Law

National Forest Roads and Trails Act of 1964 (78 Stat. 1089; 16 U.S.C. 532-538)

Section 1 of the National Forest Roads and Trails Act states “Congress hereby finds and declares that 

the construction and maintenance of an adequate system of roads and trails within and near the 

national forests and other lands administered by the Forest Service is essential.” This system of roads 

is needed “to provide for intensive use, protection, development, and management of these lands 

under principles of multiple use and sustained yield of products and services.” (16 U.S.C. 532)

Section 2 of this act states, “The Secretary is authorized, under such regulations as he may prescribe, 

subject to provisions of this Act, to grant permanent or temporary easements for specified periods or 

otherwise for road rights-of-way (1) over national forest lands administered by the Forest Service.” 

(16 U.S.C. 533)

Implicit in this legal direction is Forest Service authority to withdraw lands from vegetation 

production and related soil productivity on the national forest for dedication to road and trail 

corridors for transportation and access uses.

National Environmental Policy Act of 1969

This report was developed using the principal elements from the National Environmental Policy Act 

(NEPA) of 1969 and the regulations for implementing the procedural provisions of the NEPA from 

the Council on Environmental Quality (40 CFR Parts 1500-1508) and Regulation 36 CFR Part 220.

National Forest Management Act of 1976 (90 Stat. 2949; 16 U.S.C. 1608)

Section 8(b) of the National Forest Management Act states, “any road constructed on land of the 

National Forest System in connection with a timber contract or other lease shall be designed with the 

goal of reestablishing vegetation cover on the roadway and areas where vegetation cover has been 

disturbed by the construction of the road, within ten years after the termination of the contract, 

permit, or lease.” This section of the act further states, “Such action shall be taken unless it is 

determined that the road is needed for use as a part of the National Forest Transportation System.”

This legal direction states that lands no longer needed for, and dedicated to, transportation or access 

uses should be returned to a vegetated state. Implicit in this legal direction is Forest Service 

responsibility to recover soil productivity on these lands, to the extent that vegetation can be reestablished. Type and degree of soil recovery necessary for re-establishment of vegetation would 

depend on site-specific conditions and land management objectives for that area.
Over-snow Vehicle Use Designation

Tahoe National Forest

182

Section 8(c) of this act states “Roads constructed on National Forest System lands shall be designed 

to standards appropriate for the intended uses, considering safety, cost of transportation, and impacts 

on land resources.”

Resource Indicators and Measures 

Resource indicators and measures shown in table 19 will be used to measure and disclose effects to 

soils related to OSV use designations and grooming trails for OSV use.

Table 60. Resource indicators and measures used to determine impacts on soil resources

Resource Element Resource Indicator Measure

(Quantify if possible)

Soil Productivity 

and Soil Stability

OSV use on sensitive soils to include 

include wet meadows, areas with low 

stability or erosion hazards.

Acres of cross-country travel open to OSV 

use on sensitive soils

Soil Stability Minimum snow depths on trails 

designated for public OSV use

Depth of snow (inches)

Soil Productivity Minimum snow depths in areas 

designated for cross-country OSV use

Depth of snow (inches)

Methodology

The soil resources were analyzed within the project area using GIS data, soils survey data, corporate 

soils data layers including the geology and geomorphology layers for the Tahoe National Forest, a 

variety of reports and assessments of OSV impacts, and professional experience and judgement 

using scientific literature on OSV impacts. To determine where sensitive soils might be located on 

the forest, the soils data and other corporate GIS layers were used to determine where wet meadow 

soils, soils with low stability, and soils with erosion potential might be located.

Spatial and Temporal Context for Effects Analysis

Direct/Indirect and Cumulative Effects Boundaries

The spatial boundaries for analyzing the direct, indirect, and cumulative effects to the soil resource 

are the area of land managed by the Tahoe National Forest. 

The short-term temporal boundary for analyzing the direct, indirect, and cumulative effects to the 

soil resource is 1 year; the long-term temporal boundary is 10 years because climate changes, 

unforeseeable future projects, and other factors make assumptions beyond this timeframe 

speculative.

Affected Environment 

Existing Condition 

The Tahoe National Forest has diverse vegetation because of its wide ranges in precipitation and 

elevation. In the upper elevations between 3,500 and 6,000 feet on the western slopes of the Sierra 

Nevada Mountains, mixed conifer stands dominate. On the lower elevation areas and on south-facing 

slopes, ponderosa pine are most commonly found. California black oak, madrone and tanoak are 

hardwood species that are commonly found within the mixed conifer stands within the forest. Jeffrey 

pine is commonly found in association with the serpentine ultra-mafic soil types on the forest.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

183

Soils and Geology

The western third of the Tahoe National Forest contains deep canyons separated by nearly level to 

sloping, broad ridgetops. Soils on the steep canyon side slopes have developed mainly from 

metasedimentary and ultrabasic (ultramafic) bedrock; soils on the ridgetops have developed 

primarily from andesitic tuff breccia mudflows of the Meherten Formation (approximately 

168,232 acres or 20 percent of the forest). Soils in the vicinity of Bullards Bar Reservoir have 

developed mainly from granitic bedrock. The western third of the forest contains the most productive 

soils. Soils in the east third of the forest occur on gentle to steep slopes and in broad valleys. These 

soils have developed from rhyolitic and granitic bedrock and from alluvial deposits. Low 

precipitation is a major limitation to productivity in this area. Soils at higher elevations (5,500 to 

9,500 feet) along the crest of the Sierra have developed from volcanic, metasedimentary, and granitic 

rocks, and from glacial-alluvial deposits. Steep slopes and shallow, rocky soils limit productivity in 

much of this central third of the forest.

Elevations throughout the forest range from 2,500 to 8,700 feet. The western and southern sections 

are composed of gentle to steep slopes; the northern and eastern sections have larger swaths of gently 

sloping and flatter stretches of land. The higher elevation portions of the forest were glaciated in the 

last ice age.

Soil Productivity

Soil organic matter and soil porosity are two indicators of soil productivity. The importance of soil 

organic matter cannot be overstated (Jurgensen et al. 1997). This organic component contains a large 

reserve of nutrients and carbon, and it is dynamically alive with microbial activity. The character of 

forest soil organic matter influences many critical ecosystem processes, such as the formation of soil 

structure, which in turn influences soil gas exchange, soil water infiltration rates, and soil waterholding capacity. Soil organic matter is also the primary location of nutrient recycling and humus 

formation, which enhances soil cation exchange capacity and overall fertility. Organic matter 

including the forest floor and large woody material are essential for maintaining ecosystem function 

by supporting moderate soil temperatures, improved water availability and bio-diversity (PageDumroese et al. 2010).

Soil porosity refers to the amount and character of void space within the soil. In a “typical” soil, 

approximately 50 percent of the soil volume is void space. Pore space is lost primarily through 

mechanical compaction. Three fundamental processes are negatively impacted by compromised soil 

pore space:

• Gas exchange;

• Soil water infiltration rates; and

• Water-holding capacity.

Gas Exchange

Soil oxygen is fundamental to all soil biologic activity. Roots, soil fauna, and fungi all respire, using 

oxygen while releasing carbon dioxide. When gas exchange is compromised, biologic activity is also 

compromised. Maintaining appropriate soil biologic activity is paramount when considering longterm forest vitality.

Soil Water Infiltration Rates

Severely compacted soils do not allow appropriate water infiltration, leading to overland flow and 

associated erosion, sediment delivery, spring flooding, and low summer flows. Activities on moist 
Over-snow Vehicle Use Designation

Tahoe National Forest

184

soils are especially damaging. Activities on dry or frozen soils maintains much more of a soil’s 

natural ability to quickly restore pore spaces.

Soil productivity within the Tahoe National Forest could be most affected by OSV use within 

sensitive soil types including wet meadow areas and soils that are prone to erosion. Wet meadows are 

located on less than one percent of the Tahoe National Forest (approximately 2,487 acres). 

Maintaining a minimum snow depth to not disturb the organic matter at the soil surface or compact 

the soil and reduce soil porosity are essential to reducing the effects of OSV use on the soil resource 

in these sensitive areas.

Soil Stability

Shallow debris slides are the most common and most destructive type of landslide found on the 

Tahoe National Forest, but deeper mass movements, road cut failures, stream channel instability, and 

rockfalls also occur. Land instability is not extensive on the forest. Most instability features are found 

in the steep canyons and inner gorges in the lower elevations of the western part of the forest. 

Preliminary landslide hazard work shows a higher rate of occurrence of land sliding in various 

contact zones beneath the Meherten Formation (volcanic mudflows, 168,232 acres or approximately

22 percent of the forest), more often on north-facing slopes where springs occur. Other potentially 

unstable areas on the forest include scree and talus deposits (1,691 acres). Generally, the instability 

and slumping only occurs when soils are excavated deeper than 2 feet. Most of the remaining 

portions of the forest have low-relief volcanic topography where the stability hazard is low. Old 

landslides are present within the project area on less than 1 percent of the forest (2,314 acres). None 

of the actual proposed snowmobile trails (groomed or ungroomed) occur on any mapped landslide 

deposits.

Approximately 285,134 acres (approximately 34 percent of the area) across the forest have a very 

severe erosion hazard rating when the soils have no vegetation present.

Existing roads could also have soil erosion (Cacek 1989). The dominant processes in roaded areas 

are surface erosion from bare soil areas of roads, including the cutslope, fillslope, and travelway. 

Snow cover on roads is an important component in reducing risks of erosion from roads due to OSV 

use.

Environmental Consequences

Alternative 1 

Direct and Indirect Effects

Soil Productivity

Incidental direct effects of OSV use on and off trails could include compaction, rutting, and 

disturbance of the forest floor and organic matter within the soil in low-snow areas. Although 

snowmobiles generally have low ground pressure, the tracks on snowmobiles could churn soil and 

cause compaction with repeated travel over areas with low-snow conditions (Baker and Buthmann 

2005; Gage and Cooper 2009). This type of incidental contact with the soil surface or low-snow

conditions would likely occur during the fall or spring season, would more likely be found on ridges 

that are windy and exposed or on south-facing slopes, and would be very limited. Repeated 

compaction of snow can also alter soil temperatures potentially changing or reducing microbial 

activity, but some research has shown that with repeated compaction, soil temperatures were not 

affected (Gage and Cooper 2009; Keller et al. 2004).
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

185

Currently, grooming generally occurs when there is 12 to 18 inches of snow on trails, meaning that 

there is little to no chance that soil will be exposed on groomed OSV trails. 

Soils within the Tahoe National Forest that may be most prone to compaction and rutting include the 

soils located within the wet meadows. These soils tend to have more soil moisture for longer periods 

throughout the year with finer soil textures. Monitoring of wet meadow areas is recommended to 

ensure that OSV use is not occurring without adequate snow levels to protect these sensitive soil 

types that cover less than 1 percent of the forest. 

Moderate snowpack levels have been shown to minimize the potential compaction from OSV use 

(Gage and Cooper 2009). With adequate snow depth, on-trail and off-trail OSV use would have 

minimal to no impact on the soil resource and would not likely lead to any loss of soil productivity.

Because there is no minimum snow depth, loss of soil productivity is likely to occur in areas where 

the snow depth is less than 12 inches and cross-country OSV travel is occurring. 

Soil Stability 

With adequate snow depths, cross-country OSV use is unlikely to affect soil stability. There are 

approximately 127,627 acres with landslide potential that are designated for OSV use. Landslides 

within the Tahoe National Forest are generally caused by excavating soil to a depth greater than 2 

feet. OSV use on these soils would not lead to excavated soils and would likely be widely spread out 

throughout the forest versus concentrated on landslide-prone areas. Even with concentrated use on 

sites where landslide potential is high, OSV use would not likely cause landslides.

Cross-country use of OSVs could have an effect on ground disturbance that could lead to erosion, 

especially on soils derived from granitic or rhyolitic parent materials where OSV use is allowed 

(61,388 acres). Depending on site-specific factors including slope, aspect, elevation, level of use, and 

weather conditions, trails and off-trail riding on steep slopes could contribute to erosion (Baker and 

Buthmann 2005, Olliff et al. 1999). Adequate snowpack would likely mitigate erosion on these sites, 

but with no minimum snow depth required under the current management, risk of erosion is 

increased if OSV use occurs on bare soil or in areas with less than 12 inches of snow. Generally, 

OSV operators avoid traveling over bare soil because it can damage their machines.

Trail Grooming

Trail grooming occurs over a National Forest System road or trail. Adequate snowpack is present on 

the trail prior to grooming and grooming is not likely to cause impacts to the soil resource on trails or 

roads. 

Table 61. Resource indicators and measures for alternative 1 

Resource Element Resource Indicator

(Quantify if possible)

Measure

(Quantify if possible)

(Alternative 1)

Soil Productivity and 

Soil Stability

OSV use on sensitive soils 

including wet meadows, areas 

with low stability or erosion 

hazards.

Acres of cross-country travel 

open to OSV use on sensitive 

soils

190,169

Soil Stability Minimum snow depths on trails Inches of snow 0

Soil Productivity Minimum snow depths for crosscountry travelInches of snow 0
Over-snow Vehicle Use Designation

Tahoe National Forest

186

Alternatives 2, 3, 4, and 5

Minimization Measures common to all action alternatives

Minimization measures will be used to minimize damage to soil resources including soils from the 

use of OSVs for all action alternatives. Appendix E and F of the DEIS displays the minimization 

criteria for the soil resource.

Groomed Snow Trails:

• Impacts to soil would be minimized by grooming over the existing road and trail network, 

would not alter landforms or result in perceptible soil disturbance and therefore does not 

cause substantial impacts to water quality, perennial, intermittent or ephemeral streams, 

wetlands or other bodies of water.

• Impacts to soil would be minimized by grooming only when the ground surface is covered 

with adequate snowpack to prevent soil damage or soil rutting. The operator shall consider 

recent, current, and forecasted weather and snow conditions to ensure these conditions are 

met.

• Impacts to soils are minimized by OSV use of groomed trails where adequate snow cover 

ensures negligible potential for contact with bare soil and practically no disturbance of trail 

and road surfaces, and therefore, would not cause substantial impacts to water quality in 

perennial, intermittent, or ephemeral streams, or in wetlands or other bodies of water.

Cross-Country OSV use:

• Impacts to soil are minimized by requiring that cross-country OSV use only occur when and 

where there is adequate snow coverage would minimize the likelihood of adverse impacts to 

soil and water resources from OSV use on routes and open areas.

• Impacts to soil from cross-country use are minimized by clearly delineated and marked areas 

in the field where practical.

• Soil impacts are minimized by managing designated OSV areas to mitigate adverse effects to 

soil, water quality, and riparian resources from over-use by adaptive management, changing 

season-of use periods as necessary to allow rehabilitation of an area, particularly hill climb 

areas.

• Soil impacts are also minimized by closing an area if the designated use is causing 

unacceptable adverse effects to soil, water quality, and riparian resources.

Direct and Indirect Effects 

The direct and indirect effects for these alternatives are similar to alternative 1 except that alternative 

1 has more acreage open to cross-country OSV use (except under alternative 4, which has slightly 

greater acreage designated for OSV use) with no minimum snow depth required to travel cross 

country or on trails and could have the most impacts to the soil resource. Under alternatives 2, 3, 4 

and 5, OSV use can occur cross country and on existing roads and trails with a minimum snow 

depth. Under alternative 1, there is no minimum snow depth and could have the most impacts to the 

soil resource, which could lead to localized soil disturbance where there is repeated use at lower 

snow depths. Under alternative 2, minimum snow depths are recommendations only, with a focus on 

avoiding resource damage. As a result, minimum snow depths under alternative 2 may in fact be 

deeper than the recommended minimum in order to protect resources and avoid damage. The effects 

of trail grooming would be similar to those effects described under alternative 1.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

187

Soil Productivity

Impacts of OSV use on soil productivity would be similar to the impacts described under alternative

1. No new trail or road construction would occur under any of the alternatives. Because OSV use 

would occur with sufficient amounts of snow to protect the soil resource, there would not likely be 

soil disturbance including compaction or effects to soil porosity or the disturbance of organic matter 

including forest floor litter and large woody debris present on the soil surface. Existing regulations 

would allow the issuance of a closure order if snow cover had the potential to become inadequate 

during the open season. During times of the year when snowpacks are potentially more variable, 

there could be incidental indirect effects including some minor ground disturbance in low-snow 

areas. Under alternative 4, the acres open to cross-country OSV travel on sensitive soils would be 

slightly greater than under alternative 1, but that acreage would decrease under alternatives 2, 3 and 

5 (table 62). Alternative 3 would have the least impact on sensitive soils, but alternative 5 would 

have slightly more acres of sensitive soils designated for OSV use, but with a greater minimum snow 

depth of 24 inches, this alternative would likely have the least impact on soil productivity overall.

Soil Stability

Impacts of OSV use on soil stability would be similar to the impacts described under alternative 1.

OSV use would not increase landslide potential on low stability sites across the forest. Erosion 

would likely not increase with adequate snow cover, although there is slightly more risk of having

exposed bare soil on trails and roads under alternatives 2 and 4, because the minimum snow depth

for OSV travel on existing roads and trails is reduced to 6 inches of unpacked snow. Monitoring 

under these alternatives is important to determine the site-specific effects of a reduced minimum 

snow depth on the soil resource.

Table 62. Resource indicators and measures for soil resources direct and indirect effects, alternatives 2, 

3, 4 and 5

Resource 

Element

Resource 

Indicator Measure Alternative 2

Alternative 

3

Alternative 

4

Alternative 

5

Soil 

Productivity 

and Soil 

Stability

OSV use on 

sensitive soils 

including wet 

meadows, areas 

with low stability 

or erosion 

hazards.

Acres and 

percent 

designated for 

OSV use on 

sensitive soils

141,205 

(35%)

89,037 

(32%)

193,213 

(30%)

92,429 

(31%)

Soil 

Stability

Minimum Snow 

Depths on trails

Inches of snow 6 18 6 24

Soil 

Productivity

Minimum snow 

depths for crosscountry travel

Inches of snow 12 18 12 24

Cumulative Effects 

Vegetation Management

Several current and future vegetation management activities are occurring on the Tahoe National 

Forest. These ground-disturbing activities could have cumulative effects on the soil resource if the 

soil disturbance occurs in the same location as potential soil disturbance from OSV use. This is very 

unlikely, as effects of OSV use would be minimal throughout the forest. Potential road building, 

reconstruction, decommissioning and maintenance activities associated with vegetation management 
Over-snow Vehicle Use Designation

Tahoe National Forest

188

activities could increase soil disturbance and decrease soil productivity and stability where the roads 

are located. These vegetation management activities are regulated by Forest Plan standards and 

guidelines, Regional Standards, and best management practices to ensure soil productivity is 

maintained.

In general, snowmobiling is the primary winter recreational use in the action area. Snowmobiling 

primarily occurs on existing trails, naturally unforested areas, or in areas with limited forest cover or 

associated structural complexity at the ground level. Because snowmobiles operate over snow that 

protects the ground, it is unlikely that OSV use has a significant direct impact upon soils, and 

therefore, cumulative effects are not expected.

Parking Improvements for Winter Recreation

The parking lot at the Little Truckee Summit parking area is proposed for expansion to increase 

parking capacity. Approximately 10 acres of area will be disturbed during the expansion, but 5 of 

those acres will be temporarily disturbed and rehabilitated following the activities. Approximately 

5 acres of soil disturbance will be permanent. These activities would occur during the 

spring/summer/fall when there is no snow on the ground, therefore, the impacts from parking lot 

improvements would not occur at the same time as the impacts from OSV use. Adequate snow levels 

on the disturbed but rehabilitated soil areas would prevent further resource damage by OSV use.

Meadow Restoration Projects

Three meadow restoration projects are proposed on the Tahoe National Forest; Deer, Beartrap and 

Folchi. The restoration project planned in Deer Meadow would encompass approximately 15 acres of 

the meadow, Beartrap would also encompass approximately 15 acres. Both of these restoration 

projects would overlap in time and space with OSV use within the meadows, but OSV use would 

occur when sufficient snow is present to the protect the soil resource and no cumulative impacts are 

expected. No cross country OSV is permitted in the Flochi area; therefore, no overlap in time and 

space exists and no cumulative effects are expected.

Other Recreation Activities

Disturbance from general motorized use and recreational access occurs and will continue to occur 

throughout the forest indefinitely. We anticipate no changes in the existing recreation profile. Other 

recreational activities that take place off the developed roads, such as the gathering of miscellaneous 

forest products and hunting, occur within the project area, but because OSV use would generally 

occur on minimum snowpack, we anticipate no cumulative effects from other ongoing recreational 

activities. 

Climate Change

Climate change affects and would continue to affect California and the Tahoe National Forest in the 

future. Precipitation events would likely become more unpredictable and warmer temperatures will 

decrease the amount of precipitation that falls as snow, likely decreasing the total snowpack and the 

amount of time that snow will be on the ground (State of California 2007). This could increase the 

amount of time the soil would be exposed to OSV impacts, and increase the impacts on sensitive soil 

sites including wet meadows and erosive sites because of increased soil exposure.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

189

Compliance with Relevant Laws, Regulations, Policies and Plans 

This project is consistent with the Tahoe National Forest Land and Resource Management Plan,

which provides standards and guidelines to protect the soil resource and the Southwest Regional 

Soils Quality Standards by maintaining soil productivity.

Short-term Uses and Long-term Productivity 

There would be no impacts from short-term uses and long-term productivity on the soil resource.

Unavoidable Adverse Effects 

There would be no unavoidable adverse effects of any of the alternatives to the soil resource.

Irreversible and Irretrievable Commitments of Resources

There would be no irreversible and irretrievable commitments of resources for any alternatives.

Terrestrial Wildlife

The Fish and Wildlife Service list of Threatened, Endangered, and Proposed wildlife species for the 

Tahoe National Forest was obtained through the FWS Information for Planning and Conservation 

website (https://ecos.fws.gov/ipac/) from the Sacramento, and Nevada Fish and Wildlife Service 

offices, dated April 13, 2016 and again on August 21, 2016.

Relevant Laws, Regulations, and Policy

Regulatory Framework

Land and Resource Management Plan

The Tahoe National Forest LRMP provides standards and guidelines for activities on the forest

including OSV management. 

♦ LRMP Standards and Guidelines pertinent to OSV management (USDA Forest Service 

1990: Chapter 4):

• Coordination includes all activities needed to meet Regional standards and guidelines, 

legal mandates, planning direction for fish and wildlife, and to establish or maintain 

structural and nonstructural habitat improvements 

• Cooperation includes interactions with the US Fish and Wildlife Service, other Federal 

agencies, California Department of Fish and Game, County agencies, development 

interests, and universities 

• A biological evaluation will be prepared for each project involving suitable threatened 

and endangered or sensitive species habitat. The biological evaluation will address 

measures for maintaining viable population, potential impacts to the species, and 

possible alternatives to mitigate or avoid impacts

• Develop programs for endangered, threatened, and sensitive fish and wildlife species as 

outlined in appendix D. Implement recovery plans and species management plans for 

threatened and endangered species
Over-snow Vehicle Use Designation

Tahoe National Forest

190

Land Allocations and Desired Conditions

California Spotted Owl Protected Activity Centers 

Designation

California spotted owl protected activity centers (PACs) are delineated surrounding each territorial 

owl activity center detected on National Forest System lands since 1986. Owl activity centers are 

designated for all territorial owls based on: (1) the most recent documented nest site, (2) the most 

recent known roost site when a nest location remains unknown, and (3) a central point based on 

repeated daytime detections when neither nest or roost locations are known.

PACs are delineated to: (1) include known and suspected nest stands and (2) encompass the best 

available 300 acres of habitat in as compact a unit as possible. The best available habitat is selected 

for California spotted owl PACs to include: (1) two or more tree canopy layers; (2) trees in the 

dominant and co-dominant crown classes averaging 24 inches diameter at breast height (dbh) or 

greater; (3) at least 70 percent tree canopy cover (including hardwoods); and (4) in descending order 

of priority, CWHR classes 6, 5D, 5M, 4D, and 4M and other stands with at least 50 percent canopy 

cover (including hardwoods). Aerial photography interpretation and field verification are used as 

needed to delineate PACs.

As additional nest location and habitat data become available, boundaries of PACs are reviewed and 

adjusted as necessary to better include known and suspected nest stands and encompass the best 

available 300 acres of habitat.

PACs are maintained regardless of California spotted owl occupancy status. However, after a standreplacing event, habitat conditions are evaluated within a 1.5-mile radius around the activity center 

to identify opportunities for re-mapping the PAC. If there is insufficient suitable habitat for 

designating a PAC within the 1.5-mile radius, the PAC may be removed from the network.

Desired Conditions

Stands in each PAC have: (1) at least two tree canopy layers; (2) dominant and co-dominant trees 

with average diameters of at least 24 inches dbh; (3) at least 60 to 70 percent canopy cover; (4) some 

very large snags (greater than 45 inches dbh); and (5) snag and down woody material levels that are 

higher than average.

Northern Goshawk Protected Activity Centers 

Designation

Northern goshawk PACs are delineated surrounding all known and newly discovered breeding 

territories detected on National Forest System lands. Northern goshawk PACs are designated based 

upon the latest documented nest site and location(s) of alternate nests. If the actual nest site is not 

located, the PAC is designated based on the location of territorial adult birds or recently fledged 

juvenile goshawks during the fledgling dependency period.

PACs are delineated to: (1) include known and suspected nest stands and (2) encompass the best 

available 200 acres of forested habitat in the largest contiguous patches possible, based on aerial 

photography. Where suitable nesting habitat occurs in small patches, PACs are defined as multiple 

blocks in the largest best available patches within 0.5 mile of one another. Best available forested 

stands for PACs have the following characteristics: (1) trees in the dominant and co-dominant crown 

classes average 24 inches dbh or greater; (2) in west side conifer and east side mixed conifer forest 

types, stands have at least 70 percent tree canopy cover; and (3) in east side pine forest types, stands 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

191

have at least 60 percent tree canopy cover. Non-forest vegetation (such as brush and meadows) 

should not be counted as part of the 200 acres.

As additional nest location and habitat data become available, PAC boundaries are reviewed and 

adjusted as necessary to better include known and suspected nest stands and to encompass the best 

available 200 acres of forested habitat.

PACs are maintained regardless of northern goshawk occupancy status. PACs may be removed from 

the network after a stand-replacing event if the habitat has been rendered unsuitable as a northern 

goshawk PAC and there are no opportunities for re-mapping the PAC near the affected PAC.

Desired Conditions

Stands in each PAC have: (1) at least two tree canopy layers; (2) dominant and co-dominant trees 

with average diameters of at least 24 inches dbh; (3) at least 60 to 70 percent canopy cover; (4) some 

very large snags (greater than 45 inches dbh); and (5) snag and down woody material levels that are 

higher than average.

Great Gray Owl Protected Activity Centers 

Designation

PACs are established and maintained to include the forested area and adjacent meadow around all 

known great gray owl nest stands. The PAC encompasses at least 50 acres of the highest quality 

nesting habitat (CWHR types 6, 5D, and 5M) available in the forested area surrounding the nest. The 

PAC also includes the meadow or meadow complex that supports the prey base for nesting owls.

Desired Conditions

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.

Forest Carnivore Den Site Buffers

Designation

Marten den sites are 100-acre buffers consisting of the highest quality habitat in a compact 

arrangement surrounding the den site. CWHR types 6, 5D, 5M, 4D, and 4M in descending order of 

priority, based on availability, provide highest quality habitat for the marten.

Desired Conditions

Areas surrounding marten den sites have (1) at least 2 conifers per acre greater than 24 inches dbh

with suitable denning cavities, (2) canopy closures exceeding 60 percent, (3) more than 10 tons per 

acre of coarse woody debris in decay classes 1 and 2, and (4) an average of 6 snags per acre on the 

west side and 3 per acre on the east side.

California Spotted Owl Home Range Core Areas 

Designation

A home range core area is established surrounding each territorial spotted owl activity center 

detected after 1986. The core area amounts to 20 percent of the area described by the sum of the 

average breeding pair home range plus one standard error. Home range core area sizes are 

1,000 acres on the Almanor Ranger District, and 2,400 acres on the Hat Creek and Eagle Lake 

Ranger Districts.
Over-snow Vehicle Use Designation

Tahoe National Forest

192

Aerial photography is used to delineate the core area. Acreage for the entire core area is identified on 

National Forest System lands. Core areas encompass the best available California spotted owl habitat 

nearest the owl activity center. The best available contiguous habitat is selected to incorporate, in 

descending order of priority, CWHR classes 6, 5D, 5M, 4D and 4M, and other stands with at least 

50 percent tree canopy cover (including hardwoods). The acreage in the 300-acre PAC counts toward 

the total home range core area. Core areas are delineated within 1.5 miles of the activity center.

When activities are planned adjacent to lands of other ownership, circular core areas are delineated 

around California spotted owl activity centers. Using the best available habitat as described above, 

any part of the circular core area that lies on National Forest System lands is designated and 

managed as a California spotted owl home range core area.

Desired Conditions

Home range core areas consist of large habitat blocks that have: (1) at least two tree canopy layers; 

(2) at least 24 inches dbh in dominant and co-dominant trees; (3) a number of very large (greater 

than 45 inches dbh) old trees; (4) at least 50 to 70 percent canopy cover; and (5) higher than average 

levels of snags and down woody material.

Sierra Nevada Forest Plan Amendment

The following standards and guidelines applicable to terrestrial biota will be considered during the 

analysis process. Standards and guidelines described in this section apply to all land allocations, 

other than wilderness and wild and scenic river areas, unless stated otherwise.

Habitat Connectivity for Old Forest Associated Species

• 27. Minimize old forest habitat fragmentation. Assess potential impacts of fragmentation on old 

forest associated species (marten) in biological evaluations.

• 28. Assess the potential impact of projects on the connectivity of habitat for old forest associated 

species.

• 29. Consider retaining forested linkages (with canopy cover greater than 40 percent) that are 

interconnected via riparian areas and ridge top saddles during project-level analysis.

• 30. If fishers are detected outside the southern Sierra fisher conservation area, evaluate habitat 

conditions and implement appropriate mitigation measures to retain suitable habitat within the 

estimated home range. Institute project-level surveys over the appropriate area, as determined by 

an interdisciplinary team.

Wolverine Detections

• 32. 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-year period for detections not associated with a den site. Limited 

operating periods for old forest-dependent species apply only to vegetation management 

activities

Wheeled Vehicles.

• 69. 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 over-snow vehicles would continue.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

193

Standards and Guidelines for California Spotted Owl and Northern Goshawk Protected 

Activity Centers

• 75. For California spotted owl PACs: Maintain a limited operating period, prohibiting vegetation 

treatments within approximately 1⁄4 mile of the activity center during the breeding season (March 

1 through August 31), unless surveys confirm that California spotted owls are not nesting. 

• 76. For northern goshawk PACs: Maintain a limited operating period, prohibiting vegetation 

treatments within approximately 1⁄4 mile of the nest site during the breeding season (February 15 

through September 15) unless surveys confirm that northern goshawks are not nesting. 

• 77. The [CSO or NGO] limited operating period may be waived for vegetation treatments of 

limited scope and duration, when a biological evaluation determines that such projects are 

unlikely to result in breeding disturbance considering their intensity, duration, timing and 

specific location. Where a biological evaluation concludes that a nest site would be shielded 

from planned activities by topographic features that would minimize disturbance, the LOP buffer 

distance may be modified.

• 82. Mitigate impacts where there is documented evidence of disturbance to the [CSO or NGO] 

nest site from existing recreation, off-highway vehicle route, trail, and road uses (including road 

maintenance). Evaluate proposals for new roads, trails, off-highway vehicle routes, and 

recreational and other developments for their potential to disturb nest sites.

Standards and Guidelines for Great Gray Owl Protected Activity Centers

• 83. Apply a limited operating period, prohibiting vegetation treatments and road construction 

within 1⁄4 mile of an active great gray owl nest stand, during the nesting period (typically March 

1 to August 15). The limited operating period may be waived for vegetation treatments of limited 

scope and duration, when a biological evaluation determines that such projects are unlikely to 

result in breeding disturbance considering their intensity, duration, timing and specific location. 

Where a biological evaluation concludes that a nest site would be shielded from planned 

activities by topographic features that would minimize disturbance, the LOP buffer distance may 

be reduced.

Standards and Guidelines for Marten Den Sites

• 87 and 89. Mitigate impacts where there is documented evidence of disturbance to the [fisher or 

marten] den site from existing recreation, off highway vehicle route, trail, and road uses 

(including road maintenance). Evaluate proposals for new roads, trails, off-highway vehicle 

routes, and recreational and other developments for their potential to disturb den sites.

• 88. Protect marten den site buffers from disturbance from vegetation treatments with a limited 

operating period (LOP) from May 1 through July 31, as long as habitat remains suitable or until 

another regionally approved management strategy is implemented. The LOP may be waived for 

individual projects of limited scope and duration, when a biological evaluation documents that 

such projects are unlikely to result in breeding disturbance considering their intensity, duration, 

timing, and specific location. Limited operating periods for old forest-dependent species apply 

only to vegetation management activities.
Over-snow Vehicle Use Designation

Tahoe National Forest

194

Federal Law

Endangered Species Act

The Endangered Species Act of 1973 (16 U.S.C. 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 critical habitat for these species. 

Section 7 of the Endangered Species Act, as amended, requires the responsible Federal agency to 

consult the U.S. Fish and Wildlife Service (USFWS) and the National Marine Fisheries Service 

concerning any project or action that may affect a threatened or endangered species under their 

jurisdiction. It is Forest Service policy to analyze impacts to threatened or endangered species to 

ensure management activities are not likely to jeopardize the continued existence of a threatened or 

endangered species, or result in the destruction or adverse modification of critical habitat for these 

species. This assessment is documented in a biological assessment located in the project record.

Bald Eagle Protection Act

The Bald Eagle Protection Act of 1940 provides for the protection of the bald eagle and the golden 

eagle by prohibiting, except under certain specified conditions, the taking, possession, and commerce 

of such birds. The 1972 amendments increased penalties for violating provisions of the act or 

regulations issued pursuant thereto and strengthened other enforcement measures. The act defines 

“take” as “pursue, shoot, shoot at, poison, wound, kill, capture, trap, collect, molest, or disturb.” 

Disturb means to agitate or bother a bald or golden eagle to a degree that causes, based on the best 

scientific information available, (1) injury, to an eagle; (2) a decrease in its productivity, by 

substantially interfering with normal breeding, feeding, or sheltering behavior; or (3) nest 

abandonment, by substantially interfering with normal breeding, feeding, or sheltering behavior 

(USFWS 2007).

Resource Indicators and Measures 

Resource indicators and measures shown in table 19 will be used to measure and disclose effects to 

terrestrial wildlife related to OSV use designations and grooming trails for OSV use.

Table 63. Resource indicators and measures for assessing effects to terrestrial wildlife

Resource Indicator Measure

(Quantify if possible)

Resource Element: Federally Listed, Proposed Species –

North American wolverine

Potential for disturbance to individuals from OSV use and 

increased human presence, or injury or mortality of 

individuals

Acres designated for OSV use and conducive to 

OSV use of habitat affected by OSV use

Resource Element: R5 Sensitive species – Pacific Marten

Potential for injury or mortality of individuals from OSV use 

or related activities11

Acres designated for OSV use and conducive to 

OSV use of habitat affected by OSV use

Potential for loss of habitat connectivity Acres of corridors impacted by OSV use

 11 Related activities include snow plowing of roads, parking lots, and trailheads (i.e., staging areas)
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

195

Resource Indicator Measure

(Quantify if possible)

Resource Element: R5 Sensitive species – California 

spotted owl (CSO), Northern goshawk (NGO), 

Potential for disturbance to or displacement of individuals 

from noise and increased human presence, injury or 

mortality of individuals

Acres designated for OSV use and conducive to 

OSV use of important habitat impacted by OSV 

use

Acres designated for OSV use and conducive to 

OSV use of buffered CSO and NGO activity 

centers impacted by OSV use

Resource Element: R5 Sensitive species – Bald Eagle

Potential for disturbance to individuals from noise and 

increased human presence, injury or mortality of individuals

Acres open to OSV use and conducive to OSV 

use of high value reproductive habitat impacted 

by OSV use

Resource Element: R5 Sensitive species – Great Gray 

Owl

Potential for disturbance to individuals from noise and 

increased human presence, injury or mortality of 

individuals, or habitat modification

Acres open to OSV use and conducive to OSV 

use of high-reproductive habitat impacted by 

OSV use

Resource Element: R5 Sensitive species – Willow 

Flycatcher, Greater Sandhill Crane, Western bumblebee, 

and Bats (Fringed Myotis, Pallid Bat, and Townsend’s Bigeared Bat)

Potential for habitat degration Qualitative comparison

Methodology 

Species biology, habitat information, and potential for OSV-related effects, from the best available 

scientific information, were discussed in species account sections. Species occurrence information 

specific to the Tahoe National Forest was disclosed. For quantitative assessment, the amount of 

suitable habitat that could be impacted by OSV use was used to measure effects to species for t 

comparison by alternative. Specific reproductive site information, when available, was also used to 

measure effects to species.

Analysis Process

Using Geographic Information Systems, modeled habitat and reproductive sites, when available, for 

each species was intersected with areas conducive to OSV use assumptions criteria (canopy cover 

less than 70 percent, slopes less than 20 percent; see below) and areas in which OSV use would be 

permitted under each alternative. The resulting total acres and percentages of habitat, by assumption 

and alternative, were disclosed and compared. Using best available scientific information, known 

reproductive sites were buffered [California spotted owl activity center points (0.70 mile), goshawk 

PACS (0.25 mile), and bald eagle nest site points (660 feet)] to identify habitats with the greatest 

potential to be impacted by OSV use and associated activities.
Over-snow Vehicle Use Designation

Tahoe National Forest

196

Assumptions Specific to the Wildlife Resources Analysis

Snowmobile use patterns vary by day of the week, time of the day, topography, terrain, and 

vegetation. With assistance from Tahoe National Forest staff, we developed the following use 

patterns and categories to create a more accurate description of potential impacts of each alternative 

to species and habitats. Refer to the DEIS for mapped assumptions.

General OSV use patterns: 

• Primarily day use (generally 10:00 am to 3:00 pm; grooming occurs at night).

• OSV use is highest on weekends and holidays.

• Highest concentrations of OSV use occur along groomed trails (this is supported by research 

documented in State Environmental Impact Report (EIR). Generally, groomed routes are 

used to access cross-country areas. 

• Use is concentrated at trailheads.

• Higher use occurs in open meadows adjacent to groomed trail access and in flatter areas.

• OSV “high marking” occurs primarily on slopes with open vegetation, near groomed trails.

• Lower elevations generally have less OSV use – snow occurs at lower elevations less 

frequently and persists for short periods of time (2 to 5 days).

• Ungroomed routes receive 50 percent less use than groomed routes (only 25,000 registered 

OSVs in California per State EIR, most use on groomed trails). 

• OSV use is assumed to be very low (fewer than 10 riders per site per day on a weekend), 

depending on specific snow depths and daily temperatures, after the March 31 termination 

date closing roads for exclusive OSV use. Based on surveys of Forest Snow Parks and 

designated OSV route access points, OSV use was documented until the end of April, at 

which point snow levels no longer allow continued use of designated OSV routes (California 

Department of Parks and Recreation 2010). Therefore, for the purpose of this analysis, April 

30 is used as a cut-off date for the maximum period of interaction between snowmobiles and 

wildlife.

Areas Conducive to OSV Use (Moderate to High Use):

• Canopy cover less than 70 percent: CWHR vegetation (California Department of Fish and 

Wildlife 2014) 1S, 1P, 1M, 2S, 2P, 2M, 3S, 3P, 3M, 4S, 4P

• Slope less than or equal to 20 percent

High Use:

• Areas within 0.5 mile of snowmobile staging areas

• Areas within 0.5 mile of groomed trails

• Meadows within 0.5 mile of a designated OSV trail

Moderate Use:

• Areas within 0.5 mile of marked (not groomed) OSV trails
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

197

• Areas between 0.5 and 1.5 miles from groomed trails

• Meadows 10 acres or greater in size, or 0.5 to 1.5 miles from an OSV trail

Areas Not Conducive to OSV Use (Low-to-No Use):

Low Use:

• Areas below 3,500 feet elevation 

• Canopy cover greater than 70 percent: CWHR vegetation 2D, 3D, 4D, 4M; vegetation size 5 

and 6 

• Slope greater than or equal to 20 percent

• Meadows 30 acres or greater, 1.5 miles or more from an OSV trail

• Areas more than 1.5 miles from a groomed OSV trail

• Areas more than 0.5 mile from a marked (not groomed) OSV trail

Potential Use:

• CWHR vegetation open areas (annual grass, barren, lacustrine, mixed chaparral, montane 

chaparral, perennial grass, sagebrush, wet meadow and urban).

Indirect Effects (Snow Compaction)

Potential indirect effects, including snow compaction and vehicle emissions, are likely to be 

concentrated in areas conducive to OSV use.

Spatial and Temporal Context for Effects Analysis

Direct, Indirect, and Cumulative Effects Boundaries

The spatial boundaries for analyzing the direct, indirect, and cumulative effects to all of the species 

under consideration for analysis, including threatened, endangered, proposed, candidate, Forest 

Service sensitive species, and species of public interest is the Tahoe National Forest boundary 

(unless otherwise specified) for the following reasons: the forest boundary is large enough to address 

wide-ranging species and Forest Service Sensitive Species’ viability is assessed at the Forest Plan 

area. The temporal boundary for this analysis is 10 years from the signing of the decision document 

and is based on adequate time for an effectiveness monitoring program to be designed and 

implemented and for results to be assessed.

Affected Environment and Environmental Consequences for 

Endangered, Threatened or Proposed Species and/or their 

Designated Critical Habitat

Table 64 identifies wildlife species to consider because they may be present within the general area 

of the Tahoe National Forest.
Over-snow Vehicle Use Designation

Tahoe National Forest

198

Table 64. Terrestrial threatened, endangered, proposed, and candidate (TEPC) species and designated 

or proposed critical habitat considered within this analysis

Species Name TEPC 

Status12

Project 

Area Within 

Species’ 

Range

Detections 

in or Near 

the Project 

Area

Suitable 

Habitat 

Present

Species Addressed 

Further/Rationale Determination

Yellow-billed 

cuckoo 

(Coccyzus 

americanus)

FT No No No No; Project area is 

outside the known 

distribution of this 

species

NA

Yellow-billed 

cuckoo proposed 

critical habitat

NA No No No No; Project area is 

outside the 

proposed critical 

habitat

NA

California 

wolverine (Gulo 

gulo luteus)

FP/FSS Yes Yes Yes Yes May affect 

individuals, but 

are not likely to 

lead to a loss 

of viability or a 

trend toward 

Federal listing

Species Analyzed in Detail

Direct and Indirect Effects

According to Gaines et al. (2003), the interactions between snowmobile routes and focal wildlife 

species are poorly documented for many species and these interactions need to be further refined 

with additional research and monitoring. The most common interactions between snowmobile routes 

and wildlife that Gaines et al. (2003) documented from the literature included trapping as facilitated 

by winter human access, disturbance-based displacement and avoidance,

13 and disturbance at a 

specific site,

14 usually wintering areas. To a lesser degree, hunting, trapping, poaching, collection, 

and habitat loss and fragmentation15 were other interactions identified. Specific types of habitat 

modification that occurred on winter recreation routes include the effect of snow compaction16 on the 

subnivean sites used by small mammals and alteration of competitor/predator communities.

17 The 

same types of responses would be expected off of designated routes (i.e., cross country). Other 

interactions facilitated by linear recreation routes in general, but not specific to OSV use include 

vehicle collision and physiological response.

18

 12 FE = federally endangered; FT = federally listed as threatened; FP = federal proposed for listing; FC = federal candidate 

for listing; FSS = Forest Service sensitive. Sources: Official federally endangered, threatened, proposed, and candidate 

species list obtained on August 21, 2016, from the Sacramento, and Nevada U.S. Fish and Wildlife Service (USFWS) Field 

Offices and USDA Forest Service, Pacific Southwest Region, Sensitive Animal Species by Forest, June 30, 2013.

13 Spatial shifts in populations or individual animals away from human activities on or near roads, trails, or networks 14 Displacement of individual animals from a specific location that is being used for reproduction and rearing of young 15 Loss and resulting fragmentation of habitat owing modification to the establishment of roads, trails, or networks, and 

associated human activities

16 Direct mortality of animals crushed or suffocated as a result of snow compaction from snowmobile routes or groomed ski 

trails

17 A physical human-induced change in the environment that provides access for competitors or predators that would not 

have existed otherwise

18 Increase in heart rate or stress hormones when near a road or trail or network of roads or trails
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

199

Trapping

Trapping of marten or wolverine or any of the special-status species under consideration is not legal 

in California. Poaching and collecting without a valid permit are also illegal activities. These types of 

activities, facilitated by OSV use, are expected to be rare and addressed as a law enforcement issue. 

Therefore, they will not be examined in this analysis.

Disturbance 

Breeding Disruption

This type of disruption could impact late-successional species or wide-ranging carnivores. If the 

winter season overlaps with the beginning of breeding, the presence of OSVs or grooming equipment 

could disrupt courtship and nesting or denning activities due to noise and/or visual disturbance that 

result in behavioral changes in the animals. 

Winter Range and/or Home Range Use

This type of impact could impact late-successional species or wide-ranging carnivores. Noise and 

extended human presence from OSV activities could reduce the size of the winter home range for 

several wildlife species. The home range provides food, shelter, and breeding opportunity, and if it is 

reduced, could compromise species survival, particularly during stressful survival conditions in the 

winter. 

Many of the species that may be active or present during the OSV Program season are nocturnal and 

may not be affected by daytime snowmobile activities at all. However, 29 percent of snowmobilers 

report some nighttime riding (California Department of Parks and Recreation 2010) and resulting 

human disturbance could disrupt home range use by nocturnal species. Trail grooming activities 

occur at night, are infrequent, and move slowly enough that grooming is not expected to have a 

substantial negative effect on wildlife home range. For nocturnal and crepuscular species, trail 

grooming and OSV use may also result in animals avoiding areas frequented by snowmobilers and 

groomers. 

Physiological Response

Single or repeated interactions between OSVs and wildlife could lead to energy expenditures from 

flight or vigilance (orienting) reactions. The energetic cost of flight can be significant for predatory 

animals. Quantifying these physiological responses in wildlife is extremely difficult.

The grooming equipment operates infrequently and moves slowly, so it is estimated that it results in 

fewer flight or vigilance reactions. Grooming is not expected to have a substantial negative effect on 

wildlife populations as a result of physiological stress. Snowmobile use likely results in more flight 

or vigilance reactions because there are more vehicles, they move faster, and they are generally 

louder than grooming equipment. Physiological stress may impact individuals, but not populations as 

a whole.

Vehicle Collision

As previously discussed, the likelihood of a collision between snow grooming equipment and 

wildlife is extremely low because the equipment travels slowly (3 to 6 mph). There is an increased 

likelihood of collision with OSVs due to higher frequency of OSV use and higher speeds. This effect 

would be most specific to mammals. Vehicle collision would be expected to be rare and would 

impact individuals rather than populations as a whole. 
Over-snow Vehicle Use Designation

Tahoe National Forest

200

Habitat Modification

Trails as Routes for Competitors and Predators

Packed trails resulting from snowmobile use facilitate coyote incursion into deep snow areas 

(Bunnell et al. 2006) and can negatively impact marten or other mammal populations through 

increased competition and predation. A study in Utah found that 90 percent of coyote movement was 

made within 1,150 feet of packed trails (Bunnell et al. 2006).

Competition and predation, if occurring, would be predictably restricted to areas in the immediate 

vicinity of trails. The use of OSV trails and regular grooming is an existing condition that has been in 

operation for numerous years; and no new trail expansion is proposed at this time. Therefore, coyote 

incursion, if occurring, would continue, but would not increase as a result of OSV program activities.

Avoidance

For diurnal species, OSV use of the trails may result in animals avoiding areas used by 

snowmobilers.

Snow Compaction

Mechanical snow compaction can crush, suffocate, or alter the movements of subnivean fauna (small 

mammals, such as shrews, voles, pocket gophers, and mice that remain active throughout the winter 

with much of their activity occurring in the subnivean space beneath the snowpack) and medium 

sized mammals that den under the snow, such as marten. Snow compaction may impact individuals. 

However, small mammals’ population densities are dependent on numerous factors.

Threatened, Endangered, and Proposed Species, and Critical Habitat

Wide-ranging Carnivores

North American Wolverine (Gulo gulo luscus)

Species Account

There have been 21 verified detections of wolverine on the forest and 12 are within one-quarter mile 

of snowmobile routes on the Tahoe National Forest. On February 28, 2008, a lone male wolverine 

was photographed at baited camera stations on the Tahoe National Forest and adjacent Sierra Pacific 

Industries land in 2008 through 2014 (Moriarity et al. 2009; USFWS 2010; USDA Forest Service

NRIS records database 2012, CDFW 2014). These records are north of Interstate 80 in Nevada and 

Sierra counties, west and south of Sierraville, California. This was the first verified record of a 

wolverine in California since 1922. Although incidental, unconfirmed sightings of wolverine have 

been reported throughout the Sierra Nevada there is no evidence that California currently hosts a 

wolverine population or that female wolverines have made, or are likely to make, similar dispersal 

movements (USFWS 2013). The USFWS considers the Sierra Nevada Mountains to be part of the 

wolverine’s current range, but a population has not been reestablished (the single male identified in 

2008 does not make a population) (USFWS 2010).

In February 2013, the USFWS published a proposed rule to list the North American Wolverine as a 

threatened distinct population segment (DPS) in the contiguous United States (Federal Register / Vol. 

78, No. 23 / Monday, February 4, 2013 / Proposed Rules). On August 13, 2014, the USFWS 

withdrew its previous proposal (Federal Register / Vol. 79, No. 156 / Wednesday, August 13, 2014 / 

Proposed Rules). On April 14, 2016, the Court remanded the matter to the U.S. Fish and Wildlife 

Service for further consideration consistent with order CV 14-246-M-DLC (Consolidated with Case 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

201

Nos.14-247-M-DLC and 14-250-M-DLC). The species is currently considered proposed for Federal 

listing.

Habitat Status

Results of a 5-year study (Copeland et al. 2007) show wolverines used modestly higher elevations in 

summer versus winter, and they shifted use of cover types from whitebark pine (Pinus albicaulis) in 

summer to lower elevation Douglas-fir (Pseudotsuga menziezii) and lodgepole pine (Pinus contorta) 

communities in winter. In general, wolverines live at or above timberline, in areas relatively free 

from human disturbance, moving to lower elevations in winter likely due to prey availability. The 

average size of wolverine’s home range is between 300 and 500 square kilometers (186 to 

310 square miles, USFWS 2013). Home range sizes within the Sierra Nevada remain unknown.

Wolverines have been known to occupy habitats from 4,000 to over 10,000 feet elevation in the 

Sierra Nevada. The presence of deep and persistent snow appears be a major contributing factor to 

habitat selection by wolverines. Wolverine select areas that are cold and receive enough winter 

precipitation to reliably maintain deep persistent snow late into the warm season (Copeland et al. 

2010). No records exist of wolverines denning in snow-free habitats, despite the wide availability of 

these habitats within their range (USFWS 2013). Wolverines also appear to select areas that are free 

of significant human disturbance (summarized in USDA Forest Service 2001). A major threat to this 

species is loss of alpine habitat from climate change. Other possible threats to this species include 

habitat loss and fragmentation and increasing human presence. 

Breeding occurs from late spring to early fall and females give birth in natal dens that are excavated 

in the snow and require persistent, stable snow conditions greater than 5 feet deep (Magoun and 

Copeland 1998, Copeland et al. 2010) presumably as thermal and predation protection (USFWS 

2013). These dens are typically found at higher elevations than the average elevation used by nonreproductive wolverines (Magoun and Copeland 1998). Natal dens described in California were 

under rock ‘shelves’ at elevations above 10,000 feet (summarized in USDA Forest Service 2001). 

Females may use natal dens through late April or early May and may move kits to multiple maternal 

dens during May. Den abandonment is related to water accumulation from snowmelt, the maturation 

of offspring, and disturbance (USFWS 2013). 

For this analysis, a total of 317,976 acres of habitat, based on the aforementioned criteria, is found 

within the project area (based on years of snow coverage greater or equal to one year to seven years).

Threats

Potential threats to this species include habitat loss and fragmentation, loss and alteration of alpine 

(snow) habitat from climate change, and increasing human presence (disturbance). The USFWS 

(2013) noted climate change as the threat with the greatest potential to impact wolverine. A warming 

climate would likely result in a loss of suitable habitat due to increased summer temperatures and a 

reduced incidence of persistent spring snowpack. The USFWS (2013) noted recreation as an 

additional threat to wolverines because mother wolverines tend to move their kits to alternate 

denning areas once humans are detected nearby. 

Direct and Indirect Effects

Resource indicators and measures (FSH 1909.15, 12.5) used in this analysis to measure and disclose 

effects to wolverine are listed in table 65.
Over-snow Vehicle Use Designation

Tahoe National Forest

202

Table 65. Resource indicators and measures for assessing effects to wolverine

Resource Indicator 

and Effect

Measure

(Quantify if possible)

Alternatives 

1 and 2

Alternative 

3

Alternative 

4

Alternative 

5

Potential for 

disturbance to 

individuals from OSV 

use and increased 

human presence, or 

injury or mortality of 

individuals

Acres of habitat 

affected by OSV use

32,546 32,479

(

39,941 29,829

The most common interactions between snowmobile routes and wildlife that Gaines et al. (2003) 

documented from the literature included trapping as facilitated by winter human access, disturbancebased displacement and avoidance,19 and disturbance at a specific site,20 usually wintering areas. 

Snowmobile use and associated activities within habitats for wide-ranging carnivores, such as 

wolverine, can affect individuals or their habitat (Gaines et al. 2003). Direct effects include: 

(1) displacement from or avoidance of human activity on or near roads; (2) displacement of 

individual animals from breeding or rearing habitat; and (3) physiological response to disturbance 

resulting in changes in heart rate or level of stress hormones.

There is also potential for injury or mortality to individuals from vehicle collision. As previously 

discussed, the likelihood of a collision between snow grooming equipment and wildlife is extremely 

low because the equipment travels slowly (3 to 6 mph). There is an increased likelihood of collision 

with OSVs due to higher frequency of OSV use and higher speeds. Vehicle collision with a 

wolverine would negatively affect that particular animal, but the likelihood of occurrence is assumed 

to be rare.

Direct effects include behavioral modification such as altered or dispersed movement as caused by a 

route or human activities on or near a route.

Although recreational activities such as snowmobiling and backcountry skiing can affect wolverines 

(USFWS 2013), OSV use and related activities would not physically modify suitable wolverine 

habitat. Wolverines, if present, would be expected to have little interaction with snowmobiles or 

snow grooming equipment, whereas the majority of snowmobile use occurs during the daytime, 

wolverine are highly nocturnal and snow grooming equipment moves at a very slow speed not likely 

to impact individuals. In addition, wolverines are known to avoid roads and areas of human 

habitation; areas within 0.5 mile of OSV trails and staging areas receive the highest use and no new 

trails are proposed under any of the alternatives.

Comparison of the Alternatives

Table 66 shows the amounts of wolverine habitat in which a wolverine, on the Tahoe National 

Forest, could be subject to direct or indirect effects of OSV use and associated activities. Forty-four

percent of suitable wolverine habitat is designated for OSV use in alternatives 1 and 2. OSV-related 

noise-based disturbance, injury, or mortality impacting individual wolverines would be most likely 

to occur within that 44 percent of suitable habitat. In addition, of that 44 percent of habitat, high 

OSV use is concentrated within 0.5 mile of snowmobile staging areas, on and within 0.5 mile of 

groomed trails, and in meadows within 0.5 mile of a designated OSV trail, so the majority of OSV 

 19 Spatial shifts in populations or individual animals away from human activities on or near roads, trails, or networks 20 Displacement of individual animals from a specific location that is being used for reproduction and rearing of young
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

203

use occurs within less than that 44 percent of wolverine habitat. Similarly, under alternatives 3 and 4, 

45 percent and 48 percent, respectively, of wolverine habitat would be open and conducive to OSV 

use. Under alternative 5, 41 percent of wolverine habitat would be open to and conducive to OSV 

use. 

Table 66. Acres of wolverine habitat with potential to be impacted by OSV use and related activities, by 

alternative 

Alternative 

1

Alternative 

2

Alternative 

3

Alternative 

4

Alternative 

5

Designated OSV Acres 315,209 315,209 315,734 315,079 305,423

Total acres of wolverine habitat 317,976 317,976 317,976 317,976 317,976

Designated for OSV use and 

conducive to OSV use

142,139 142,139 145,484 155,302 132,499

Total 144,906 144,906 147,726 158,199 145,052

Cumulative Effects

Wolverine habitat overlaps with areas vegetation management projects, areas open to Christmas tree 

and firewood cutting and use of roads within wolverine suitable habitat after the termination date of 

the Forest Order closing roads for exclusive OSV use could occur. Due to their secretive nature, 

wolverines are likely to avoid roaded or heavily used roaded areas where disturbance or 

displacement would be more likely. Similarly, most non-motorized winter recreation occurs along 

designated trails and wolverine would probably avoid heavily used trails. Similar activities on State 

and private lands within the forest boundary may impact habitat availability outside of National 

Forest System lands and may increase disturbance locally. However, the possibility of this type of 

disturbance is unknown.

In summary, ongoing and reasonably foreseeable actions may be additive locally, but are not 

expected to contribute significantly to impacts to wolverine discussed for the project under any of the 

alternatives. However, the cumulative effects would be slightly different by alternative, though not 

enough to be measurably different with alternative 5 having the least and alternative 4 having the 

most cumulative impacts.

Determination Statement

Alternatives 1, 2, 3, 4, and 5 of the Tahoe National Forest Over-snow Vehicle Use Designation 

Project may affect, but are not likely to adversely affect wolverine based on the following rationale: 

• The single male wolverine detected near Truckee, California, is genetically most closely related 

to, and most likely came from, a population on the western edge of the Rocky Mountains, rather 

than either the historic California population. There is no evidence that California currently hosts 

a wolverine population or that female wolverines have made, or are likely to make, similar 

dispersal movements into the area. 

• Vegetative composition or structure of suitable wolverine habitat would not be physically 

modified by OSV use or related activities. 

• Although the potential for noise-based disturbance to individuals within suitable habitat ranges 

from 41 to 48 percent of suitable habitat under all of the alternatives, the percentage of suitable 

wolverine habitat impacted would actually be lower considering that the concentration of OSV 

use is not equal across the landscape. 
Over-snow Vehicle Use Designation

Tahoe National Forest

204

• Wolverines, would be expected to have little interaction with snowmobiles or snow grooming 

equipment: whereas the majority of snowmobile use occurs during the daytime, wolverine are 

highly nocturnal and snow grooming equipment moves at a very slow speed not likely to impact 

individuals. In addition, wolverines are known to avoid roads and areas of human habitation.

Affected Environment and Environmental Consequences for 

Sensitive Species and/or their Suitable Habitat

Table 67 identifies sensitive wildlife species to consider, because they may be present within the 

general area of the Tahoe National Forest.

Table 67. Terrestrial Forest Service Sensitive Species considered in this analysis

Species Name

Project Area 

Within 

Species’ 

Range

Detections in 

or Near the 

Project Area

Suitable 

Habitat 

Present

Species 

Addressed 

Further/

Rationale

Determination

Late-successional Forest 

species

Fisher

(Pekania pennanti)

No No No No

Project area 

is outside the 

known 

distribution of 

this species

NA

Pacific marten (Martes caurina) Yes Yes Yes Yes May affect individuals, but 

are not likely to lead to a 

loss of viability or a trend 

toward Federal listing

California spotted owl (Strix 

occidentalis occidentalis)

Yes Yes Yes Yes May affect individuals, but 

are not likely to lead to a 

loss of viability or a trend 

toward Federal listing

Northern goshawk (Accipiter 

gentilis)

Yes Yes Yes Yes May affect individuals, but 

are not likely to lead to a 

loss of viability or a trend 

toward Federal listing

Bats

Fringed myotis (Myotis 

thysanodes)

Yes Yes Yes Yes May affect individuals, but 

are not likely to lead to a 

loss of viability or a trend 

toward Federal listing

Pallid bat (Antrozous pallidus) Yes Yes Yes Yes May affect individuals, but 

are not likely to lead to a 

loss of viability or a trend 

toward Federal listing

Townsend’s big-eared bat 

(Corynorhinus townsendii)

Yes Yes Yes Yes May affect individuals, but 

are not likely to lead to a 

loss of viability or a trend 

toward Federal listing

Species that Utilize Riparian 

or Wetland Habitats

Bald eagle (Haliaeetus 

leucocephalus)

Yes Yes Yes Yes May affect individuals, but 

are not likely to lead to a 

loss of viability or a trend 

toward Federal listing
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

205

Species Name

Project Area 

Within 

Species’ 

Range

Detections in 

or Near the 

Project Area

Suitable 

Habitat 

Present

Species 

Addressed 

Further/

Rationale

Determination

Great gray owl (Strix nebulosa) Yes Yes Yes Yes May affect individuals, but 

are not likely to lead to a 

loss of viability or a trend 

toward Federal listing

Willow flycatcher (Empidonax 

traillii)

Yes Yes Yes Yes May affect individuals, but 

are not likely to lead to a 

loss of viability or a trend 

toward Federal listing

Greater Sandhill crane (Grus 

canadensis tabida)

Yes Yes Yes Yes May affect individuals, but 

are not likely to lead to a 

loss of viability or a trend 

toward Federal listing

Terrestrial Invertebrates

Western bumble bee (Bombus 

occidentalis)

Yes No Yes Yes May affect individuals, but 

are not likely to lead to a 

loss of viability or a trend 

toward Federal listing

Late-successional Forest Species

Pacific Marten (Martes caurina)

Species Account

There are numerous marten detections documented on the Tahoe National Forest, although there are 

currently no known marten dens sites identified. Moriarty (2011) indicates that various 4M habitat 

types (lodgepole pine, montane riparian, red fir, subalpine conifer, and white fir) are considered 

“high quality habitat” for marten. CWHR also classifies some 4M habitat as high quality denning 

habitat for marten. 

Habitat Status

In the Sierra Nevada, this species is known to inhabit high-elevation (4,500 to 10,500 feet) latesuccessional, mature red fir and lodgepole pine forests with large, decadent live trees and snags, and 

complex physical structure near the ground composed of an abundance of large dead and downed 

wood (Buskirk and Powell 1994 in Ruggiero et al. 1994, Zielinski 2014). Martens can inhabit 

younger forests if important elements of the mature forest are still present, especially structures for 

resting and denning (Purcell et al. 2012, Zielinski 2014). Riparian areas, especially near mature 

forest, are important for foraging (Zielinski 2014). There are 203,242 acres of suitable marten winter 

habitat on National Forest System lands within the Tahoe National Forest boundary.

Because marten predictive denning habitat models are currently lacking, the best that can be done at 

this point is to use the marten landscape-level habitat model produced by Kirk and Zielinski (2009) 

that identifies high predictability areas for martens. In doing so, one would assume that areas of high 

predicted suitability would also be indicative of where den sites would occur. However, this model 

has low spatial resolution and is probably no better than using the reproductive component of CWHR 
Over-snow Vehicle Use Designation

Tahoe National Forest

206

as a predictive model (B. Zielinksi, pers. comm.). Based on CWHR habitat types, currently, there are 

154,081 acres of high-capability reproduction habitat21 on Tahoe National Forest.

Threats

Martens are sensitive to recreation activities, particularly snow activities (e.g., ski facilities). Much 

of the information presented on marten and ski resorts comes directly from Zielinski (2013). Ski 

resorts are considered likely to affect marten populations because they remove and fragment highelevation fir forest habitat. The operation of ski resorts includes the continued compaction of snow, 

presence of high densities of skiers, and nocturnal grooming activities. These factors can have 

negative effects on marten both directly (females may avoid these areas) or indirectly (snow 

compaction and forest fragmentation facilitate high predation by coyotes) (Slauson et al. 2008). 

Skiers and staff are active during the day, and grooming and some skiing activity occur during the 

night. Thus, martens that are sensitive to these activities may not find time for important foraging 

activities. 

There are approximately 25 ski resorts in the Sierra Nevada, and nearly all occur within the range of 

the marten (Zielinski 2013). The Lake Tahoe region includes approximately half of these resorts (not 

all found on the Lake Tahoe Basin Management Unit), constituting the highest density of resorts in 

the Sierra Nevada and one of the highest in North America (Zielinski 2013). 

Other snow activities may affect marten, but data from the Lake Tahoe Basin Management Unit

indicate that OHV/OSV use did not affect marten occupancy or probability of detection and that 

overall OHV/OSV use in the study areas was low (1 OHV/OSV pass every 2 hours) and exposure 

occurred in less than 20 percent of a typical home range (Zielinski et al. 2008).

In a study of marten in northeastern California, Kirk and Zielinksi (2009) reported that marten 

populations detected are associated with areas that contain the largest amount of reproductive habitat 

consisting of mature, old forest. The highest density of detections was located in the largest protected 

area in the study region. Moriarty (2011) reported approximately 60 percent fewer detections of 

marten at Sagehen Experimental Forest on the Tahoe National Forest than those in the 1980s. These 

results, although on a smaller spatial scale, are similar to those reported by Kirk and Zielinksi (2009). 

Although the cause of the decreased detections is unclear, Moriarty (2011) hypothesized that this was 

associated with loss and fragmentation of habitat; during the same period 39 percent of forested areas 

at Sagehen Experimental Forest experienced some form of timber harvest (11 percent clearcut or 

shelterwood and 28 percent salvage). Habitat and occupancy models developed by Spencer and 

Rustigian-Romsos (2012) indicate that habitat connectivity for marten south of the Plumas National 

Forest, does not appear to be greatly limiting for martens, although the authors suggest that Interstate 

80 may be a significant barrier to movement. 

Under the assumption that OSV use would disrupt marten movement within connectivity corridors 

(even though there would be no changes in habitat), functional habitat connectivity for martens on 

the Tahoe National Forest was assessed using GIS cost-distance and least-cost corridor modeling 

(Kirk and Zielinski 2010). This effort involved two primary steps. First, the landscape was modeled 

as a permeability surface, which described the relative costs to dispersing martens for moving across 

each linkage from known source and destination locations. Second, least-cost algorithms were used 

to determine the least-cost movement corridors, using the “corridor” function, and least-cost path, 

using the “costdistance” function (see Kirk and Zielinski 2010 for a full description). Dispersal 

corridors calculated using the “costdistance” and “corridor” functions mapped every possible 

 21 Jeffrey pine, lodgepole pine, montane hardwood, montane hardwood-conifer, montane riparian, ponderosa pine, red fir, 

Sierran mixed conifer, subalpine conifer, and white fir CWHR types 4M, 4D, 5M, 5D, 6 mixed above 5,000 feet.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

207

movement pathway across the landscapes defined by each linkage. Corridors with the lowest total 

resistance costs were assumed to be the most essential for successful movement. Corridors that 

depicted the most likely dispersal routes, the top 10 percent and 25 percent, respectively, were 

extracted from the model. The top 10 percent corridors were generally within the middle of the wider 

25 percent corridors. For this analysis, the 25 percent corridors model was used to assess the 

potential for impact to marten functional habitat connectivity. There are 79,583 acres of 25 percent

corridors on National Forest System lands within the Tahoe National Forest boundary.

Direct and Indirect Effects

Resource indicators and measures (FSH 1909.15, 12.5) used in this analysis to measure and disclose 

effects to marten (utilizing the methodology conducive to OSV use outltlined above) are listed in

table 68. Acres per alternative are derived from high, moderate and low criteria analysis. Alternative 

5 has the least amount of OSV trails proposed.

Table 68. Resource indicators and measures for assessing effects to marten

Resource Indicator 

and Effect

Measure

(Quantify if 

possible)

Alternative

1 

Alternative

2

Alternative

3

Alternative

4

Alternative

5

Potential for 

disturbance to 

individuals from noise 

and increased human 

presence, injury or 

mortality of 

individuals, habitat 

modification (i.e., 

altered movement 

due to OSV use), or 

snow compaction 

effects to foraging or 

denning individuals

Acres of suitable 

habitat impacted 

by OSV use

4,831 4,831 4,826 4,831 4,460 

Potential for loss of 

habitat connectivity

Acres of corridors 

impacted by OSV 

use

18,297 18,297 18,107 18,411 ( 17,511 

Marten associated with late-successional forests can be impacted by activities associated with routes. 

Gaines et al. (2003) conducted a literature review of 71 late-successional forest-associated wildlife 

species and identified negative effects on these species that can result from route-associated factors. 

These impacts include direct loss of habitat from type conversion, diminished quality of habitat 

attributes or fragmentation, and road avoidance or displacement resulting from direct harassment or 

noise disturbance. Individuals, environmental groups, and agency biologists have expressed growing 

concern over habitat fragmentation for late-successional forest-associated species. Various studies 

have shown that this species group is vulnerable to disturbance, changes in habitat, or displacement 

by habitat generalists.

The most common interactions between snowmobile routes and wildlife that Gaines et al. (2003) 

documented from the literature included trapping as facilitated by winter human access, disturbancebased displacement and avoidance,22 and disturbance at a specific site,23 usually wintering areas. To 

 22 Spatial shifts in populations or individual animals away from human activities on or near roads, trails, or networks. 23 Displacement of individual animals from a specific location that is being used for reproduction and rearing of young.
Over-snow Vehicle Use Designation

Tahoe National Forest

208

a lesser degree, hunting, trapping, poaching, collection, and habitat loss and fragmentation were 

other interactions identified. Trapping of marten, or any of the special-status species under 

consideration, is not legal in California and, therefore, will not be considered as an impact in this 

analysis.

Snowmobile use within late-successional forest habitats can have direct effects to individuals or their 

habitat (Gaines et al. 2003) by disturbance and possible injury or mortality to individuals from 

vehicle collisions. 

Disturbance:

• Displacement of populations or individual animals from a route, related to human activities.

• Disturbance and displacement of individuals from breeding or rearing habitats.

• Physiological response to disturbance, resulting in changes in heart rate or level of stress 

hormones.

Potential for Injury or Mortality to Individuals from Vehicle Collision:

As previously discussed, the likelihood of a collision between snow grooming equipment and 

wildlife is extremely low because the equipment travels slowly (3 to 6 mph). There is an increased 

likelihood of collision with OSVs due to higher frequency of OSV use and higher speeds. This effect 

would be most specific to mammals.

Possible indirect effects include:

• Altered or dispersed movement as caused by a route or human activities on or near a route

• Creation of a vector pathway for competitors or predators

• Snow compaction impacts to den sites or subnivean prey

In addition to the roads and trails themselves and associated infrastructure, human use of the trails 

and roads for dispersed recreation activities (e.g., driving, hiking, mountain biking, OHV and OSV 

use) can lead to direct mortality and injury in the form of vehicle strikes; temporary and permanent 

displacement of wildlife; alteration of normal behavior and activities by wildlife species (e.g., 

foraging, nesting, denning, etc.); and spread of noxious weeds. Prolonged or consistent use of trails 

and roads can lead to permanent displacement of individuals from territories, nest or den 

abandonment, and/or alteration of foraging behavior and species-specific effects can lead 

community-wide effects. Higher trophic level species, such as marten, may be particularly 

vulnerable to disturbances from dispersed recreation activities (Manley et al. 2004). OSV use does 

not modify vegetative composition or structure.

Disturbance

As OSV trail use is an existing condition, animals that occur in the areas affected by OSV use during 

winter may be habituated to OSV disturbance or may have already modified their behavior to avoid 

areas adjacent to trails or OSV noise resonating in the forest may cause an alert or startle response in 

individual animals or may be accepted as ambient noise conditions of the environment as suggested 

by the study on martens (Zielinski et al. 2007). Although Zielinski et al. (2007), in investigating the 

response of marten to OHV and OSV-related disturbance in the Sierra Nevada Mountains in 

California, did not demonstrate an effect of OHV and OSV use on marten occupancy, probability of 

detection, sex ratio, or activity patterns, the study did not measure behavioral, physiological, or 

demographic responses, so it is possible that OHVs and OSVs may have effects, alone or in concert 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

209

with other threats (e.g., timber harvest) that were not quantified in this study. However, those types 

of responses would be expected to affect individuals rather than the population as a whole. 

Potential for Injury or Mortality to Individuals from Vehicle Collision

Although there is an greater likelihood of collision of individual martens with OSVs than trail 

grooming equipment due to higher frequency of OSV use and higher speeds, OSV use occurs in 

more open areas (canopy cover less than 70 percent) and martens generally avoid habitats that lack 

overhead cover (canopy cover less than 30 percent) such as trails and meadows, where OSV use 

would be most pronounced. Presumably, a marten would hear an OSV and flee prior to injury or 

collision.

Competition and Predation

OSV use compacts snow and some predators may use compacted snow for travel, changing the 

spatial pattern of their movements and predation (Manley et al. 2004). Buskirk and Powell (1994) 

documented predation on marten by coyotes, red foxes, and great-horned owls. Roads driven during 

the winter months provide travel corridors for coyotes to enter into marten winter habitat, affecting 

marten through competition or direct predation. Since marten have unique morphology that allows 

them to occupy deep snow habitats where they have a competitive advantage over carnivores, such 

as coyotes and bobcats, human modifications of this habitat, such as winter road use, over-the-snow 

travel, and snowmobile trails, can eliminate this advantage and increase access for predators and 

competitors. Perrine et al. (2010) reported in the Sierra Nevada red fox conservation assessment that 

coyotes appear to be expanding their winter season range and identified this as a risk factor to the 

endemic red fox, needing further investigation. However, the recent species report (USFWS 2015b) 

noted there isn’t any information to indicate that coyotes are increasing at any of the Sierra Nevada 

red fox sighting areas that overlap with marten observation areas. It is unknown if or how much 

competition with or predation on martens by coyotes is occurring on the Tahoe National Forest as the 

result of OSV-related snow compaction or other OSV-related activities.

Snow Compaction Effects to Denning Individuals or Subnivean Prey

Martens access subnivean space beneath the snow to prey on subnivean species and use a variety of 

structures including rock crevices, for maternal den sites. Impacts related to OSV use on marten den 

sites are unknown at this time, but could be an issue given the overlap marten whelping 

(March/April) season with the OSV use season and the potential for compaction of subnivean habitat 

where natal and maternal dens may be found (B. Zielinski, pers. comm.). Although there currently 

are no documented marten den sites on the Tahoe National Forest, as they are located, Sierra Nevada 

Forest Plan Amendment standards and guidelines designed to protect marten den sites24 would apply. 

OSV-related impacts to marten dens that consist of underground squirrel middens, snags, or logs for 

denning sites would be expected to be minor and primarily noise disturbance-based due to their 

structure. Rock crevice-based dens could be subject to a greater degree of impact if the rocks are 

small enough to compact under the weight of an OSV, in which case they could lead to crushing or 

burying of individuals.

Although OSV use or related activities would not physically alter the vegetative composition or 

structure of marten habitat, martens, or their prey species, could be subject to OSV-related impacts 

from snow compaction, including suffocation or alteration of movement while foraging in the 

 24 “Mitigate impacts where there is documented evidence of disturbance to the den site from existing recreations, offhighway vehicle routes, trail, and road uses (including road maintenance). Evaluate proposals for new roads, trails, offhighway vehicle routes, and recreational and other developments for their potential to disturb den sites.”
Over-snow Vehicle Use Designation

Tahoe National Forest

210

subnivean space beneath the snow. In addition, some small mammals (i.e., voles) may have difficulty 

navigating through compact snow layers (Manley et al. 2004). Alternative 5 is least impactive for 

subnivean habitat, with alternative 4 having the most impact.

Comparison of the Alternatives

The potential for impacts to marten habitat would be greatest in areas most conducive to OSV use 

(high OSV-use areas). As described in the assumptions section, flatter areas with slopes less than 

20 percent and canopy cover less than 70 percent, including the routes and staging areas, themselves, 

are more conducive to OSV than others and, therefore, likely to receive the highest use. Those 

assumptions have been incorporated into the following analysis.

Based upon the information displayed in table 69, 95 percent of marten winter habitat is currently 

designated for OSV use (alternative 1). Under alternative 2, the acres represented are over 5,000 feet, 

therefore, marten winter habitat is slightly different for alternatives 3, 4, and 5 because the amount of 

acres not designated for OSV use varies by alternative. OSV-related noise-based disturbance, injury 

or mortality, competition or predation, or snow compaction effects (den sites or subnivean prey) 

impacting individual martens would be most likely to occur within that 9 percent of winter habitat. 

The amount of habitat under the remaining alternatives is similar to alternative 1: alternative 2, 9

percent; alternative 3, 9 percent; alternative 4, 8 percent; and alternative 5, 9 percent.

There are no known marten den sites within the Tahoe National Forest.

Table 69. Acres of marten winter habitat25 by alternative

Alternative 

1

Alternative 

2

Alternative 

3

Alternative 

4

Alternative 

5

Designated for OSV use 193,071 193,071 194,359 222,053 171,178

Total acres of marten winter habitat 203,424 203,424 203,843 233,800 205,323

Designated and conducive to OSV 

use

18,708 19,612 19,588 25,607 17,846

Marten whelping season (March – April) overlaps with the latter portion of the OSV season. Den 

sites occurring within the subnivean space could be physically impacted; minimum snow depth could 

be used to analyze impacts to marten denning and subnivean habitat by alternative to determine 

whether disturbance is occurring and if changes in management are necessary. As previously 

described, once OSV trail grooming season ends on March 31, trail use declines by roughly 50 

percent and, therefore, the possibility of direct and indirect effects to marten dens is expected to be 

low.

Of the modeled marten connectivity habitat (dispersal corridors) on the Tahoe National Forest, 

95 percent is currently designated for OSV use (table 70). Under alternative 2, the acres represented 

are over 5,000 feet, therefore, acres of marten connectivity habitat is slightly different for alternatives 

3, 4, and 5 because the amount of acres not designated for OSV use varies by alternative. However, 

23 percent (38 percent under alternative 2) is designated and conducive to OSV use. Of that 23 

percent (and 38 percent) of habitat, high OSV use is concentrated within 0.5 mile of snowmobile 

staging areas, on and within 0.5 mile of groomed trails, and in meadows within 0.5 mile of a 

designated OSV trail, so the majority of OSV use occurs within less than 23 percent of marten 

habitat. This would be the same under alternative 2. There is little difference in the amount of marten 

 25 Rustigian-Romsos and Spencer (2010) Conservation Biology Institute Marten Habitat Suitability Model.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

211

connectivity habitat that would be open to and conducive to OSV use under the other three 

alternatives (23 percent under alternative 3, 23 percent under alternative 4, and 21 percent under 

alternative 5), but alternative 5 would have the least impact on marten connectivity habitat overall.

Table 70. Acres of marten habitat connectivity corridors26, by alternative

Alternative 

1

Alternative 

2

Alternative 

3

Alternative 

4

Alternative 

5

Designated for OSV use 75,401 75,401 74,868 75,671 70,391

Total acres of marten habitat connectivity 

corridors

79,583 79,583 78,364 79,853 81,392

Designated and conducive to OSV use 18,297 18,297 18,107 18,411 17,511

As previously noted, data from the Lake Tahoe Basin Management Unit indicate that OHV and OSV 

use did not affect marten occupancy or probability of detection when overall OHV and OSV use in 

the study areas washigh. OSV use is concentrated within 0.5 mile of snowmobile staging areas, on 

and within 0.5 mile of groomed trails, and in meadows within 0.5 mile of a designated OSV trail and 

moderate use occurs within 0.5 mile of marked trails and in areas between 0.5 and 1.5 miles of 

groomed trails. Therefore, the majority of OSV use would occur within less than 8 to 9 percent of 

marten winter habitat or 21 to 23 percent of connectivity habitat. Similar to the results of natal and 

maternal den research, the results of other types of research, as it becomes available, would be used

to determine whether or not disturbance is occurring and if changes in management are necessary.

Cumulative Effects

Actions that could result in a cumulative impact to marten, when combined with alternatives 1, 2, 3, 

4, or 5 include vegetation management projects and firewood and Christmas tree cutting. Vegetation 

management projects are very small in comparison to OSV areas and/or do not overlap with 

groomed and ungroomed OSV routes or staging areas where the highest OSV use occurs. 

Other ongoing and foreseeable future activities include livestock grazing, recreation, timber harvest, 

fuel reduction, woodcutting activities, wildfire suppression, and other activities. These activities may 

affect some individuals, but no trends toward Federal listing or loss of species viability are expected 

due to protective measures deemed necessary during environmental analysis and implemented as 

required. Disturbance to individuals may be expected by the increase in OSV activities as the 

numbers of national forest visitors’ rise. In general, most non-motorized winter recreation occurs 

along designated trails, where individuals would either avoid a specific area, if too great a 

disturbance, or habituate to the noise. Timber harvest, fuel reduction, fire suppression, emergency 

responses, and other actions carried out by Federal workers or contractors are typically able to 

provide adequate protection for species. In addition, seasonal limited operating periods that prevent 

disturbance to marten denning sites would be used to minimize disturbance to these sites once they 

have been identified.

Determination Statement

Alternatives 1, 2, 3, 4 and 5 of the Tahoe National Forest Over-snow Vehicle Use Designation 

Project may affect individuals, but are not likely to lead to a loss of viability or a trend toward 

Federal listing for marten based on the following rationale:

 26 Least Cost 25% Corridor Modeling (Kirk and Zielinski 2010).
Over-snow Vehicle Use Designation

Tahoe National Forest

212

• Vegetative structure or composition of marten habitat would not be physically modified by OSV 

use and related activities under any of the alternatives.

• Although the potential for impacts to individuals within winter habitat ranges from 8 to 9 percent 

under all of the alternatives, and connectivity habitat ranges from 21 to 23 percent, it is unknown 

if OSV use or related activities on the Tahoe National Forest is negatively impacting marten 

using winter habitat or connectivity habitat, and the percentage of winter habitat and connectivity 

habitat impacted by OSV use would actually be lower considering that the concentration of OSV 

use is not equal across the landscape, with the highest use occurring on or within 0.5 mile of 

groomed routes and staging areas. Available research suggests that OHV and OSV use did not 

affect marten occupancy or probability of detection when overall OHV and OSV use in the study 

areas was low. 

• Martens tend to avoid the open areas preferred by OSV users. Therefore, the potential for 

disturbance or collisions along existing roads and trails is expected to be low under all 

alternatives.

• Den sites within above-ground structures (trees, snags) would not be physically impacted due to 

the types of structures that are used.

• Marten prey species in meadow areas may be affected by OSV compaction with varying effects 

depending on minimum snow depth. Cross country snow depth varies depending on the 

alternative, between 12 to 24 inches.

• Marten whelping season (March – April) overlaps with the latter portion of the OSV season. Den 

sites occurring within the subnivean space could be physically impacted, minimum snow depth 

could be used to analyze impacts to marten denning and subnivean habitat by alternative to 

determine whether or not disturbance is occurring and if changes in management are necessary,

thereby minimizing impacts to marten.

• It is unknown if or how much competition with or predation on martens by coyotes is occurring 

on the Tahoe National Forest as the result of OSV-related snow compaction or other OSV-related 

activities.

California Spotted Owl (Strix occidentalis occidentalis)

Species Account

Natural Resource Manager (NRM)27 currently has 190 recorded activity centers on the Tahoe 

National Forest. There are 663,936 acres of California spotted owl important habitat,

28 including 

high reproductive habitat, on the Tahoe National Forest.

Habitat Status

In the Sierra Nevada Province, spotted owls use the following five vegetation types in the Sierra 

Nevada: foothill riparian hardwood, ponderosa pine hardwood, mixed-conifer forest, red fir forest, 

and east side pine forest (USDA Forest Service 2001). Mixed-conifer forest is used most frequently 

 27 The Natural Resource Manager (NRM) is a system of database tools for managing agency data across the Forest Service. 

NRM includes: Forest Service ACtivity Tracking System (FACTS), Infrastructure (Infra), Natural Resource Information 

System (NRIS), and Timber Information Manager (TIM) applications. NRM applications provide tools for most of the 

agency's natural resource business areas.

28 Habitat types important for late-successional forest species include stands typed as 4M, 4D, 5M, 5D, and 6 by California 

Wildlife Habitat Relationship (CWHR), which are all stands of trees greater than 11 inches dbh with greater than 

40 percent canopy cover (Sierra Nevada Forest Plan Amendment, USDA Forest Service 2004). In addition, a 7,600-foot 

elevational limit was included based upon species elevational range (CDFW 2015).
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

213

by this species in the Sierra Nevada: approximately 80 percent of known sites are found in mixedconifer forest, 10 percent in red fir forest, 7 percent in ponderosa pine/hardwood forest, and the 

remaining 3 percent in foothill riparian/hardwood forest and eastside pine (Ibid). In northern 

California, the species’ elevational range extends from sea level to approximately 7,600 feet (CDFW 

2015b).

Spotted owl home ranges, and nesting and roosting locations are strongly associated with mature 

coniferous forests with high tree canopy cover (70 percent or greater), multi-layered canopies, and an 

abundance of large trees and snags (Forsman et al. 1984, Bias and Gutierrez 1992, Call et al. 1992, 

Verner et al. 1992, Bond et al. 2004, Chatfield 2005). Spotted owl foraging habitat consists of a 

broader range of vegetation types that may include younger, more open habitat (Williams et al. 2011, 

Roberts and North 2012, Keane 2013). Large coarse woody debris is a key habitat feature of spotted 

owl prey.

Spotted owl nest stands may be occupied by breeding spotted owls from February until October. 

Nesting behavior is initiated in February or early March when pairs begin roosting together and 

calling to each other more frequently at dusk before foraging or when returning to roost before dawn 

(Forsman 1976, Forsman et al. 1984). Egg laying occurs in March or April (Ibid). Hatching peaks 

May 7 to 21 (Sierra Nevada), and fledging (young leaving the nest) occurs generally when the 

nestlings are 34 to 36 days old (Forsman et al. 1984). The post-fledging dependency period extends 

through late summer; dispersal from the natal site occurs in September or October (Gutierrez et al. 

1995b, Miller 1989). A spotted owl ecology study found that approximately 90 percent of juveniles 

fledged by July 8 (Blakesley et al. 2010).

Throughout the Sierra Nevada, California spotted owl nesting habitat is protected in California 

spotted owl protected activity centers (csoPACs). A csoPAC includes 300 acres of the highest quality 

nesting habitat available, and the most recent nest site or activity center within a spotted owl 

breeding territory as described in management direction for the forest (USDA Forest Service 2004b). 

A home range core area includes its associated PAC, is 1,000 acres in size, and is composed of the 

best available contiguous habitat. The core area corresponds with 20 percent of a breeding pair home 

range plus one standard error. Home ranges vary substantially across the range of this subspecies. 

Home range sizes of California spotted owls tend to be smallest in lower-elevation hardwood forests, 

intermediate in size in conifer forests of the central Sierra Nevada, and largest in true fir forests in 

the northern Sierra Nevada (Verner et al. 1992). Neal et al. (1990) reported that California spotted 

owl home ranges in Sierra Nevada mixed conifer forests averaged 3,400 acres, including about 

460 acres in stands with 70 percent or greater canopy cover, and about 1,990 acres in stands with 40 

to 69 percent canopy cover. Verner et al. (1992) generally concur with these data, indicating that 

Sierra National Forest owls were found to have a median home range for pairs of approximately 

3,000 to 5,000 acres. However, Verner et al. (1992) cite an overall mean home range size of owl pairs 

during the breeding period in Sierran conifer forests of about 4,200 acres. 

Focused studies on northern spotted owls (Shasta-Trinity and Mendocino National Forests), have 

been conducted to evaluate direct effects of noise on the species during its breeding timeframes.

Behavioral responses to disturbance, such as leaving an area, can be readily observed (Tempel and 

Gutierrez 2003). Physiological responses to disturbance are not as easy to detect because they are not 

necessarily associated with behavioral responses (Tempel and Gutierrez 2003). Results from this 

study indicate that there were reduced reproductive success, particularly in adult males in response to 

acute traffic exposure (Hayward et al. 2011). The highest sensitivity appeared to occur among males 

in May when they were the sole providers for their mates and offspring, suggesting that spring may 
Over-snow Vehicle Use Designation

Tahoe National Forest

214

be a particularly important time to limit motorized recreation near northern spotted owl territories 

(Ibid.).

Threats

Potential threats and stressors to spotted owls include high-severity stand-replacing fires, expansion 

of barred owls (Strix varia), loss of large trees and dense canopy cover, habitat fragmentation, 

climate change, and disease.

Direct and Indirect Effects

Resource indicators and measures (FSH 1909.15, 12.5) used in this analysis to measure and disclose 

effects to California spotted owl are listed in table 71.

Table 71. Resource indicators and measures for assessing effects to California spotted owl

Resource Indicator and 

Effect

Measure

(Quantify if 

possible)

Alternative 

1 

Alternative

2

Alternative 

3

Alternative 

4

Alternative

5

Potential for disturbance to 

or displacement of 

individuals from noise and 

increased human 

presence, injury or 

mortality of individuals

Acres of 

important 

habitat 

impacted by 

OSV use

6,262 3,757 6,262 8,453 5,411

Potential for disturbance to 

or displacement of 

individuals from OSV use 

and increased human 

presence, injury or 

mortality of individuals

Acres of 

buffered CSO 

activity centers 

impacted by 

OSV use

11,885 7,131 11,885 16,293 12,108

Gaines et al. (2003) conducted a literature review of 71 late-successional-forest-associated wildlife 

species and identified negative effects on these species that can result from route-associated factors. 

Impacts included road avoidance or displacement resulting from direct harassment or noise 

disturbance. Individuals, environmental groups, and agency biologists have expressed growing 

concern over habitat fragmentation for late-successional forest-associated species. Various studies 

have shown that this species group is vulnerable to disturbance, changes in habitat, or displacement 

by habitat generalists.

Snowmobile use within late-successional forest habitats can have direct effects to individuals or their 

habitat (Gaines et al. 2003) by disturbance and injury or mortality to individuals from vehicle 

collisions. 

Disturbance:

• Displacement of populations or individual animals from a route, related to human activities.

• Disturbance and displacement of individuals from breeding or rearing habitats.

• Physiological response to disturbance, resulting in changes in heart rate or level of stress 

hormones.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

215

Potential for Injury or Mortality to Individuals from Vehicle Collision:

Although California spotted owlscould collide with OSVs or grooming equipment, the likelihood is 

very low for the following reasons: spotted owls spend little time at ground level; they are nocturnal

and most OSV use on the Tahoe occurs during daytime hours; and although snow grooming 

equipment operates during darkness, the equipment travels slowly (3 to 6 mph).

Potential Indirect effects include:

• Altered or dispersed movement as caused by a route or human activities on or near a route.

• Snow compaction (prey base for several of the other late-successional forest species under 

consideration).

In addition, Gaines et al. (2003) found an interaction that occurred on winter recreation routes was 

the indirect effect of snow compaction on the subnivean sites used by small mammals in which small 

mammals can either be suffocated as a result of the compaction, or their subnivean movements can 

be altered owing to impenetrable compact snow. Adverse effects to subnivean animals could 

indirectly affect the prey base for many Forest Service sensitive species, including California spotted 

owl.

According to Forsman et al. (1984) spotted owl courtship behavior usually begins in February or 

March with the timing of nesting and fledging varying by elevation and latitude. April 1 coincides 

with incubation in most areas (USFWS 2012a). The OSV grooming season generally begins in midDecember and continues through March. Start and stop times vary by trail location and are 

dependent upon the presence and depth of snow. As described in the assumptions section for the 

purpose of this analysis, April 30 will be used as the cut-off date for the maximum period of 

interaction between California spotted owls and OSV use and related activities.

The Forest Service considers activities farther than 0.25 mile (400 meters) from a spotted owl nest 

site to have little chance of affecting nesting spotted owls. Snowmobiles passing within 0.25 mile of 

unsurveyed nesting/roosting habitat or an active nest could disturb nesting California spotted owls.

OSV use can affect California spotted owls either directly through disturbance or displacement of 

individuals from routes, breeding or rearing habitats, physiological response to disturbance or 

potential for injury or mortality from collision, or indirectly through altered or dispersed movement 

caused by a route or human activities on or near a route. However, due to the structural nature of 

suitable habitat (i.e., dense forested stands), the level of cross-country travel in California spotted 

owl suitable habitat is expected to be relatively low, and most disturbance is likely to occur primarily 

along existing roads and trails. Based on the OSV use assumptions, once OSV trail grooming ends, it 

is estimated that use of those trails declines by 50 percent. Therefore, the possibility of direct and 

indirect effects to csoPACs within 0.25 mile of groomed trails would decrease after March 31.

Habitat would not be physically modified by OSV use and related activities.

Under all alternatives, groomed and ungroomed routes and staging areas occur within 0.25 mile of 

California spotted owl activity centers and/or important habitat. However, OSV use is not consistent 

across all available habitat. Although we don’t know specifically where impacts will occur at any 

given time and we cannot quantify the amount of impact, we know the impacts would be greatest in 

areas most conducive to OSV use (high OSV-use areas). As described in the assumptions section, 

flatter areas with slopes less than 20 percent and canopy cover less than 70 percent, including the 

routes and staging areas, themselves, are more conducive to OSV than others and, therefore, likely to 

receive the highest use. Those assumptions have been incorporated into the following analysis.
Over-snow Vehicle Use Designation

Tahoe National Forest

216

Behavioral responses to disturbance, such as leaving an area, can be readily observed in spotted owls 

(Tempel and Gutierrez 2003) and sensitivity in adult male spotted owls in response to acute traffic 

exposure was highest in May (Hayward et al. 2011). The intensity and duration of noise-generating 

activities tested by Hayward et al. (2011) are not expected to occur as a result of the proposed action 

because the maximum period of interaction between OSVs and related activities occurs before May 

when breeding adult males are most sensitive to noise. Noise associated with snowmobile use and 

associated activities in the action area is expected to be of short duration (amount of time it would 

take to travel through any given area) and of intermittent intensity (amount of concentrated noise).

Based upon OSV use patterns described in the assumptions section, once OSV trail grooming ends, it 

is estimated that use of those trails declines by 50 percent. Therefore, the potential for direct and 

indirect effects to activity centers within 0.25 mile of groomed trails would decrease substantially 

after March 31 for alternatives 1 through 3, but not necessarily for alternative 4. Due to the structural 

nature of important spotted owl habitat (i.e., dense forested stands), the level of cross-country travel 

occurring in this habitat is less than the amount of available habitat. The potential for noise-based 

disturbance is actually expected to be lower because use, and therefore, the highest potential for 

disturbance is expected within 0.5 mile of existing roads, trails and staging areas, under all 

alternatives. Habitat would not be physically modified by OSV use and related activities.

Trail grooming occurs on existing roads and trails and primarily occurs at night when fewer species 

are active, but when spotted owls are more active. Trail grooming would not physically modify 

habitat. Under all alternatives the grooming season generally begins in mid-December and continues 

through March. Start and stop times vary per trail location dependent upon snow presence. 

Grooming starts in most locations with minimum snow depth of 12 inches. Trails are prioritized for 

grooming based on visitor use. Grooming on priority trails occurs several times per week and after 

major storms. Trail grooming occurs as soon as possible after a storm in which snow accumulations 

have been substantial. The ideal air temperature for grooming is 35 degrees Fahrenheit or less with 

the temperature dropping. Wet snow requires a lower temperature to set and is best groomed at night.

Potential effects of noise disturbance would be the same as those noted due to OSV use. In addition, 

trail grooming and night riding could disturb owls that forage at night. A passing trail grooming 

machine or OSV may interrupt owl foraging, result in owl prey taking refuge, or cause owls to 

redirect their foraging away from trail areas. However, due to the limited frequency29 and duration of 

trail grooming at any trail segment location, as well as grooming activity being an ongoing operation 

for many years on the same trail routes, the noise disturbance from trail grooming would not have a 

significant impact on breeding or foraging spotted owls.

Although OSV use or related activities would not physically alter the vegetative structure of spotted 

owl habitat, spotted owl prey species that use the subnivean space could experience OSV-related 

impacts from snow compaction, including suffocation or alteration of movement while foraging in 

the subnivean space beneath the snow. The degree of this impact is unknown, but would be more 

likely in areas most conductive to OSV use.

Comparison of the Alternatives

Table 72 and table 73 show and compare, by alternative, the acres of known activity centers buffered 

by 0.70 mile and important California spotted owl habitats, respectively, with the potential for direct 

and indirect effects from OSV use and related activities. The 0.70 mile buffer covers the protected 

 29 Grooming operations at most trail systems currently operate near a maximum level. Trails are prioritized for grooming 

based on visitor use. Grooming on priority trails occurs several times per week and after significant storms. Snow removal 

on access roads and trailhead parking areas, serving the OSV Program trail systems, occurs several times during storm 

events as necessary dependent upon weather conditions (California Department of Parks and Recreation 2010).
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

217

activity center plus .25 miles to estimate potential impacts within the protected activity centers, the 

buffer, and the core area. Table 72 shows that approximately 30 percent of the total amount of 

important CSO habitat across the Forest falls within the criteria used for the alternatives. Eight 

percent of California spotted owl activity centers buffered by 0.70 mile are currently designated for 

OSV use (alternative 1). However, only 2 percent is designated and conducive to OSV use. 

Similarly, under alternative 2, 13 percent of important California spotted owl habitat would be

designated for OSV use, but only 1 percent would be designated and conducive to OSV use. The 

potential for OSV-related impacts to California spotted owls, including noise-based disturbance, 

snow compaction impacting subnivean space of prey species, or injury/mortality, would be most 

likely to occur in those areas conducive to OSV use. In addition, the buffered activity centers and the 

important habitat open to and conducive to OSV use, high OSV use would be concentrated within 

0.5 mile of snowmobile staging areas, on and within 0.5 mile of groomed trails, and in meadows 

within 0.5 mile of a designated OSV trail, so the majority of OSV use occurs within an even smaller 

percentage of each of those habitats. This would be similar under the other three alternatives. 

Table 72. Acres of known California spotted owl activity centers, buffered by 0.70 mile, with potential to 

be impacted by OSV use and related activities, by alternative

Alternative 1 Alternative 2 Alternative 

3

Alternative 

4

Alternative 

5

Designated for OSV Use 6,262 10,174 6,262 8,453 5,411

Total acres of California 

spotted owl activity center, 

buffered by 0.70 miles

75,684 75,684 75,684 84,542 74,833

Designated for OSV use and 

conducive to OSV use

1,605 2,388 1,605 2,093 1,344

Under alternative 2, 41 percent of important California spotted owl habitat designated for OSV use,

and 1 percent of important California spotted owl habitat would be designated for and conducive to 

OSV use, over 5,000 feet elevational limit. The Forest would use the results of ongoing inventory 

and monitoring of California spotted owl activity centers to determine whether or not disturbance is 

occurring and if changes in management are necessary. The potential for noise-based disturbance 

would largely overlap with roughly the first 20 percent, or the pair bonding, mating, and egg laying 

stages, of the March 1 through August 15 California spotted owl breeding season under all 

alternatives. As previously described, once OSV trail grooming season ends on March 31, trail use 

declines by roughly 50 percent and, therefore, the potential for direct and indirect effects to activity 

centers within 0.25 mile of groomed trails would decrease by an estimated 50 percent after March 31 

for all alternatives.

Table 73. Acres of important California spotted owl habitat with potential to be impacted by OSV use 

and related activities, by alternative

Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Designated for OSV use 188,610 81,718 189,959 218,213 166,943

Total acres of important 

CSO habitat

199,519 199,519 200,235 230,722 201,659

Designated and 

conducive to OSV use

6,262 2,388 6,262 8,453 5,411
Over-snow Vehicle Use Designation

Tahoe National Forest

218

Cumulative Effects

Ongoing and reasonably foreseeable actions may be additive locally to individual California spotted 

owls, but, given the small scale for the potential of overlap of cumulative effects in time and space 

with any of the alternatives, they are not expected to contribute substantial impacts to effects 

discussed for the project under any of the alternatives.

Determination Statement

Based upon the best available data and scientific information, all of the alternatives of the Tahoe 

National Forest Over-Snow Vehicle Use Designation Project would impact individuals, but are not 

likely to lead to a trend toward Federal listing or a loss of viability for California spotted owl in the 

Forest Plan area based on the following rationale:

• OSV proposed actions would not physically modify the vegetative structure or composition of 

any suitable (nesting, roosting or foraging), dispersal, or capable habitat within the project area.

• Due to the structural nature of suitable habitat (i.e., dense forested stands), the level of crosscountry OSV travel in California spotted owl suitable habitat is expected to be relatively low, 

and most disturbance is likely to occur primarily along existing roads and trails. Although the 

potential for noise-based disturbance to individuals within important habitat ranges from 82 to

94 percent, and individuals within buffered PACs ranges from 2 to 3 percent, under all of the 

alternatives, the percentage of habitats impacted would actually be lower considering that the 

concentration of OSV use is not equal across the landscape. 

• OSV-related noise-based disturbance would overlap with only the early part of the March 1 

through August 31 California spotted owl breeding season.

• OSV use is most common on trails. Once OSV trail grooming season ends on March 31, trail use 

declines by roughly 50 percent and, therefore, the possibility of direct and indirect effects to 

activity centers within 0.25 mile of groomed trails would decrease by an estimated 50 percent

after March 31 for alternatives 1 through 3 (and not long, thereafter, for alternative 4, with the 

exception of extremely high snowfall years).

• The forest would use the results of ongoing inventory and monitoring of spotted owl activity 

centers to determine whether disturbance is occurring and if changes in management are 

necessary, thereby minimizing impacts to California spotted owl. 

• Other than a single OHV study, with uncharacteristically high disturbance exposure times, there 

is no evidence of a disturbance impact to individuals or reproductive output.

• There is no evidence linking OSV noise-based disturbance to long-term population declines.

• Disturbance to California spotted owl foraging behavior would be limited primarily to areas 

adjacent to OSV trails and short-term in nature during trail grooming because the species is 

nocturnal and most OSV use occurs in the daytime.

• The potential for OSV collision with individual California spotted owls is very low due to the 

unlikeliness that an individual would stay in an area with the high noise disturbance.

Northern Goshawk (Accipiter gentilis)

Species Account

Goshawk territories on Tahoe National Forest are managed as protected activity centers (ngoPAC) 

under direction prescribed by the Sierra Nevada Forest Plan Amendment (USDA Forest Service 

2004). Based upon the best available data, there are 16,085 acres of ngoPACs. Each of the 128 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

219

ngoPACs is buffered by 0.25 miles, and 673,767 acres of goshawk important habitat,

30 including 

high-reproductive habitat, on the Tahoe National Forest.

Habitat Status

The northern goshawk prefers mature forests with large trees on moderate slopes with open 

understories. They nest in coniferous, deciduous, or mixed-pine forests, depending on availability 

(Squires and Reynolds 1997). The northern goshawk is a year-round resident throughout most of 

California. 

Northern goshawk nesting habitat at the nest stand scale has consistently greater canopy cover, 

greater basal area, greater numbers of large-diameter trees, fewer small-diameter trees, less 

understory cover, and gentle to moderate slopes relative to non-used, random sites (USDA Forest 

Service 2001). The northern goshawk breeding season is February 15 through September 15.

Goshawks are morphologically adapted to foraging in forested habitats, but are also adapted to 

ambushing prey in open habitats (summarized in Squires and Reynolds 1997). In California, mature 

and old-growth habitat (20.8 inches and greater dbh, canopy closure 40 percent and greater) were 

used, whereas open habitats such as meadows and early seral areas were avoided in mixed-conifer 

forests (Austin 1993). 

Northern goshawk nest areas may be occupied by breeding goshawks from mid-February until late 

September, and are the focus of all movements and activities associated with nesting. Goshawks may 

have multiple nest areas within their home range, and nest areas may be used intermittently for many 

years. Nest areas have relatively high canopy cover (typically greater than 50 percent) and a high 

density of large trees.

The home range increases in size from the breeding season to the non-breeding season and is 

generally larger for males than for females throughout the year. During the breeding season, the 

average home range of northern goshawks in the Lake Tahoe area is 6,745 acres for males and 

5,040 acres for females. Non-breeding season home ranges averaged 23,448 acres for males and 

13,888 acres for females (Keane 1999). Home ranges include areas with a greater proportion of 

larger tree size classes and higher density classes than that randomly available across the landscape. 

The area within the home range, but outside the post-fledging family area, is often referred to as the 

foraging area (Reynolds et al. 1992). 

Goshawks are well known to be territorial and exhibit high site fidelity (Detrich and Woodbridge 

1994). In the Sierra Nevada, northern goshawk nesting habitat is protected by the delineation of 

ngoPACs. Northern goshawk PACs are delineated to include the best available 200 acres of nesting 

habitat, and the most recent nest site and alternate nests within a goshawk breeding territory as 

described in management direction for the forest (USDA Forest Service 2001, USDA Forest Service 

2004). The size of the PACs corresponds with criteria reported by Detrich and Woodbridge (1994) 

such that territory occupancy rates of approximately 100 percent were associated with clusters of 

nest stands totaling 150 to 200 acres (USDA Forest Service 2001). 

It is important to note that goshawk PACs and territories do not correlate on a one-to-one basis. The 

territories currently recognized are based on retrospective examination of approximately 34 years 

(1977 to 2010) of surveys, whereas goshawk PACs are delineated prospectively as nesting and/or 

 30 Habitat types important for late-successional forest species include stands typed as 4M, 4D, 5M, 5D, and 6 by California 

Wildlife Habitat Relationship (CWHR), which are all stands of trees greater than 11 inches dbh with greater than 

40 percent canopy cover (Sierra Nevada Forest Plan Amendment, USDA Forest Service 2004). 
Over-snow Vehicle Use Designation

Tahoe National Forest

220

occupancy are discovered. The prospective delineation of PACs is a conservative management

approach. The forest also follows a conservative approach in eliminating goshawk PACs, which in 

some cases results in multiple PACs within a single territory. To keep consistency for this analysis, a 

0.25 buffer was used around a goshawk activity center, at the center of the ngoPAC.

Threats

A study conducted by Morrison et al. (2011) in the Lake Tahoe Basin indicated that northern 

goshawks are susceptible to human disturbance; human activity was twice as high within 

infrequently occupied territories as compared to frequently occupied territories. Many kinds of 

human activities have been documented to affect raptors by altering habitats; physically harming or 

killing eggs, young, or adults; and by disrupting normal behavior (Postovit and Postovit 1987, 

Delany et al. 1999 as cited in Morrison et al. 2011). A recent study on nesting northern goshawk 

response to logging truck noise found that while goshawks alerted (turned their head in the direction 

of the noise) to the noise, they did not flush and response was inversely proportional to the distance 

of the nest from the road (Grubb et al. 2012).

Little is known about the goshawk’s sensitivity or responses to human disturbance (Dunk et al. 

2011). Human disturbance, including noise disturbance generated by OSVs and associated trail 

grooming equipment, could cause goshawks to abandon nests during the nesting and post-fledging 

period (February 15 through September 15). As a result, Dunk et al. (2011) experimentally tested 

whether ATVs and hikers disturb goshawks in Plumas National Forest of the Sierra Nevada. More 

specifically, they analyzed whether there was evidence of an effect of ATVs or hikers on the behavior 

or reproduction of goshawks. Given the absence of OSV/goshawk studies, this study is the closest to 

potential for disturbance from OSV use because sound levels are similar. ATVs in this study 

produced sound in the range of 70 to 110 dBA; noise from snowmobiles manufactured after June 30, 

1976, have a noise emission of 73 dBA at 50 feet while traveling at 15 mph, when tested under SAE 

J1161 procedures,31 and noise generated by snowplows and snowcats used for OSV program 

operations ranges from 80 to 85 dBA32 (California Department of Parks and Recreation 2010). Dunk 

et al. (2011) evaluated the possible effects of three kinds of recreational activity: (1) sustained 

activity by ATVs on roads near nests and fledglings (Sustained-ATV experiments), (2) direct 

approaches by ATVs or hikers toward nests (Direct-approach experiments), and (3) sustained activity 

below nests by hikers and a dog (Intensive-hiker experiments). For the purpose of this analysis, we 

will focus on Sustained-ATV experiments for nesting goshawks, because the OSV use period is 

outside of the fledgling period, and Direct-approach ATV experiments. 

Sustained-ATV treatments were designed to evaluate whether, and how, nesting goshawks and their 

young respond to sound from ATVs operated on nearby roads. Treatments consisted of driving an 

ATV for approximately 1 hour back and forth on transects on established roads near the nest, 

exposing the nest to multiple ATV passes during each treatment. Each sustained-ATV treatment 

during the nesting phase consisted of two portions: slower driving (ca. 16 kilometers per hour) and 

faster driving (ca. 24 to 32 kilometers per hour) to expose goshawks to a realistic variety of sound 

levels associated with ATV use on these kinds of roads. 

 31 This is the equivalent of a single passenger vehicle or motorcycle on a roadway. A snowmobile under full throttle emits 

the same sound level as a truck pulling a camper at a constant highway speed applying very little throttle. In a worst case 

scenario, a snowmobile leaving a stop sign and applying full throttle, the noise produced is still about the same as a 

passenger vehicle driving down the road (International Snowmobile Manufacturers Association 2008). The effect is audible 

but not long lasting (California Department of Parks and Recreation 2010).

32 This is similar to typical construction equipment (backhoe, excavator, grader). Typical hourly average noise levels from 

this equipment are 75 to 80 dBA at a distance of 100 feet. These noise levels drop off at a rate of 6 dBA per doubling of 

distance between the noise source and receptor.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

221

Three metrics of ATV impacts on goshawks were used to compare sustained-ATV treatment and 

control territories: (1) percentage of time females spent off the nest, (2) frequency of kekking [calls 

are also typically associated with alarm or agonism in goshawks (Squires and Reynolds 1997)] bouts, 

and (3) frequency of prey deliveries. There were no significant differences in the mean percentage of 

time that females spent off nests, mean number of kekking bouts, or mean number of prey deliveries 

per hour during control experiments and during sustained ATV treatments. However, a significant 

difference between treatment and control territories in the percentage of time that female goshawks 

spent off the nest during the treatment/control hour and the pre-treatment/control hour was found. 

This was interpreted to mean that sustained ATV use near nests had an effect on goshawks. However, 

based on the researchers’ extensive personal observations, the kind of activity goshawks were 

exposed to during sustained ATV treatments was more intensive than was typical recreational use of 

ATVs on the Plumas National Forest. The same would be expected of OSV use on the Tahoe 

National Forest.

The ATV used in direct nest approaches followed a pre-determined transect that, at its midpoint, 

passed directly below or as close as possible to the nest, and then returned by the same route. The 

total (round-trip) transect length was 800 meters. Direct-ATV approach treatments did not include 

slower and faster driving phases. Because they were often located on rough terrain, direct-ATV 

approaches generally required driving in lower gears at relatively slow speeds. The mean transect 

duration was 7 minutes (range 4 to 15 minutes). Nesting females did not appear to respond 

negatively to direct approaches by ATVs.

In addition, Dunk et al. (2011) evaluated whether a relationship existed between the number of 

young produced by a territory and the type(s) of experiments that occurred within it during that year 

and whether there was any evidence that the frequency or duration of research activities influenced 

reproduction. No evidence was found indicating experimental treatments, or research visits in 

general, influenced goshawk reproduction. Longer-term and more rigorous reproductive data, 

including physiological data, are needed to fully address whether recreational or research activities 

can impact goshawk reproduction. However, data suggest that recreational and research activities 

would have to be more intensive and extensive than those conducted to negatively affect goshawk 

reproduction (Dunk et. al 2011).

Direct and Indirect Effects

Resource indicators and measures (FSH 1909.15, 12.5) used in this analysis to measure and disclose 

effects to goshawk are listed in table 74.

Table 74. Resource indicators and measures for assessing effects to northern goshawk

Resource Indicator and 

Effect

Measure

(Quantify if 

possible)

Alternatives 

1 and 2

Alternative 

3

Alternative 

4

Alternative 

5

Potential for disturbance to 

individuals from noise and 

increased human 

presence, or injury or 

mortality of individuals

Acres of important 

habitat impacted by 

OSV use

2,234 2,234 3,981 1,927

Potential for disturbance to 

individuals from OSV use 

and increased human 

presence, or injury or 

mortality of individuals

Acres of buffered 

NGO PACs 

impacted by OSV 

use

14,369 14,322 16,409

(100%)

14,661
Over-snow Vehicle Use Designation

Tahoe National Forest

222

Snowmobile use within late-successional forest habitats can have direct effects to individuals or their 

habitat (Gaines et al. 2003) by disturbance and injury or mortality to individuals from vehicle 

collisions. 

Disturbance

• Displacement of populations or individual animals from a route, related to human activities.

• Disturbance and displacement of individuals from breeding or rearing habitats.

• Physiological response to disturbance, resulting in changes in heart rate or level of stress 

hormones.

Potential for Injury or Mortality to Individuals from Vehicle Collision:

The likelihood of a collision between snow grooming equipment and wildlife is extremely low 

because the equipment travels slowly (3 to 6 mph). There is an increased likelihood of collision with 

OSVs due to higher frequency of OSV use and higher speeds. However, the potential for this effect 

on goshawks would be low, given that they spend little time at ground level.

Possible indirect effects include:

Altered or dispersed movement as caused by a route or human activities on or near a route.

In addition, Gaines et al. (2003) found an interaction that occurred on winter recreation routes was 

the indirect effect of snow compaction on the subnivean sites used by small mammals in which small 

mammals can either be suffocated as a result of the compaction, or their subnivean movements can 

be altered owing to impenetrable compact snow. Adverse effects to subnivean animals could 

indirectly affect the prey base for many Forest Service sensitive species, including goshawk.

Activities greater than 0.25 mile (400 meters) from a goshawk nest site have little potential to affect 

nesting goshawks. The OSV season overlaps with the courtship through incubation phases of the 

goshawk breeding season (Woodbridge and Hargis 2006), so snowmobiles passing within 0.25 mile 

of unsurveyed nesting/roosting habitat or an active nest could disturb nesting goshawks. Although 

Dunk et al. (2011) found sustained ATV use near nests had a significant effect on the percentage of 

time that female goshawks spent off the nest during the treatment, they also noted the kind of activity 

goshawks were exposed to during sustained ATV treatments was more intensive than was typical 

recreational use of ATVs on the Plumas National Forest. The same would be expected of OSV use 

on the Tahoe National Forest. In addition, Dunk et al. (2011) found no evidence indicating 

experimental treatments, or research visits in general, influenced goshawk reproduction. As 

previously described in the California spotted owl section, monitoring and analysis specific to 

California spotted owl and northern goshawk PACs and OSV use was conducted on the Lassen 

National Forest. Lassen National Forest had 174 northern goshawk PACs, at the time, of which 33 

(19 percent) were within 400 meters of designated OSV routes. Twenty-three northern goshawk 

PACs fell within the scope of the GIS analysis conducted. No relationship was apparent between a 

PAC’s distance from a snow park and whether it was recently occupied.

Although the possibility of OSV-related noise-based disturbance overlaps with only the early part of 

the February 15 through September 15 goshawk breeding season, once OSV trail grooming season 

ends on March 31, trail use declines by roughly 50 percent. Therefore, the risk of direct and indirect 

effects to ngoPACs within 0.25 mile of groomed trails would decrease by an estimated 50 percent 

after March 31 for alternatives 1 through 3 (and not long thereafter, for alternative 4, with the 

exception of extremely high snowfall years). 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

223

Although OSV use or related activities would not physically alter the vegetative structure of 

goshawk habitat, goshawk prey species that use the subnivean space could be subject to OSV-related 

impacts from snow compaction, including suffocation or alteration of movement while foraging 

beneath the snow. The degree of this impact is unknown, but would be more likely in areas most 

conductive to OSV.

Comparison of the Alternatives

Table 75 and table 76 show and compare, by alternative, the amount of northern goshawk acres 

within a buffered activity center and important habitat, respectively, with the potential for direct 

(disturbance or displacement, injury or mortality from collision) and indirect (snow compaction 

effects to subnivean prey) effects, as previously described, and taking slope and canopy cover 

assumptions into account. Due to the structural nature of important goshawk habitat (i.e., dense 

forested stands), the level of cross-country travel in goshawk important habitat is less than the 

amount of available habitat. Ninety-nine percent of goshawk activitiy centers buffered by 0.25 mile 

are currently designated for OSV use (alternative 1). However, 12 percent is designated and 

conducive to OSV use. OSV-related impacts to goshawk, including noise-based disturbance, snow 

compaction impacting subnivean space of prey species, or injury/mortality, would be most likely to 

occur in those areas conducive to OSV use. In addition, of the 12 percent of buffered activity centers 

and the 12 percent of important habitat open to and conducive to OSV use, high OSV use is 

concentrated within 0.5 mile of snowmobile staging areas, on and within 0.5 mile of groomed trails, 

and in meadows within 0.5 mile of a designated OSV trail, so the majority of OSV use occurs within 

in an even smaller percentage of each of those habitats; 62 goshawk activity centers buffered by 0.25 

mile (48 percent) fall within 0.5 mile of a groomed trail or OSV staging area. This would be similar 

under the other four alternatives.

Table 75. Acres of goshawk activity centers, buffered by 0.25 mile, by alternative

Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Designated for OSV use 5,643 2,258 5,519 6,393 5,546

Total acres of goshawk 

PACs, buffered by 0.25 mile 5,655 5,655 5,529 6,409 5,655

Designated and conducive 

to OSV use

700 420 700 778 632

Under alternative 2, with the 5,000-foot elevational limit, 4 percent of important northern goshawk 

habitat and 7 percent of buffered activity centers would be open and conducive to OSV use. 

Similarly, 6 percent of important habitat and 12 percent of buffered activity centers would be open 

and conductive to OSV under alternative 3, 6 percent of important habitat and 12 percent of buffered 

activity centers under alternative 4, and 5 percent of important habitat and 11 percent of buffered 

PACs under alternative 5. The forest would use the results of ongoing inventory and monitoring of 

northern goshawk activity centers to determine whether disturbance is occurring and if changes in 

management are necessary. Noise-based disturbance would overlap with roughly the first 20 percent, 

or the courtship (formation of breeding pairs, nest building, and copulation) phase of the February 15 

through September 15 northern goshawk breeding season under all alternatives. The risk of direct 

and indirect effects to activity centers within 0.25 mile of groomed trails would decrease by an 

estimated 50 percent after March 31 for all alternatives. 
Over-snow Vehicle Use Designation

Tahoe National Forest

224

Table 76. Acres of important goshawk habitat by alternative

Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Designated for OSV use 365,625 288,632 356,624 365,625 279,058

Total acres of important 

goshawk habitat

481,053 481,053 481,053 481,053 481,053

Designated and conducive 

to OSV use 31,160 18,540 29,898 31,160 25,543

Cumulative Effects

Vegetation management and salvage projects are very small in comparison to the OSV use area 

and/or do not overlap with groomed and ungroomed OSV routes or staging areas where the highest 

OSV use occurs. 

Goshawk habitat overlaps with areas open to Christmas tree cutting and firewood cutting. There 

would be minimal overlap between the Christmas tree and firewood cutting season (annually 

between November 1 and December 31) and OSV trail grooming season (beginning December 26), 

and disturbance or displacement from this activity would occur outside of the northern goshawk

breeding season under all alternatives. Use of roads within goshawk habitats after the March 31 

termination date of the Forest Order closing roads for exclusive OSV use can contribute additional 

disturbance during the early part of the goshawk breeding season, particularly for nests within 

0.25 mile of roads. However, current research shows no evidence that recreational vehicle use 

influences goshawk reproduction. In general, most non-motorized winter recreation occurs along 

designated trails, and northern goshawk would either avoid roosting in those areas, if too great a 

disturbance, or habituate to the noise. Similar activities on State and private lands within the forest 

boundary and within 0.25 mile of goshawk habitats may impact habitat availability outside of 

National Forest System lands and may increase disturbance locally. However, the potential for this 

type of disturbance is unknown. In summary, ongoing and reasonably foreseeable actions may be 

additive locally to individual goshawks, but are not expected to contribute substantial impacts to 

those discussed for the project under any of the alternatives.

Determination Statement

Alternatives 1, 2, 3, 4, and 5 of the Tahoe National Forest Over-snow Vehicle Use Designation 

Project may affect individuals, but are not likely to lead to a trend toward Federal listing or loss of 

viability for the northern goshawk in the Forest Plan area based on the following rationale: 

• Vegetative structure or composition of habitat would not be physically modified by OSV use and 

related activities under any of the alternatives.

• Due to the structural nature of suitable habitat (i.e., dense forested stands), the level of crosscountry OSV travel in northern goshawk suitable habitat is expected to be relatively low, and 

most disturbance is likely to occur primarily along existing roads and trails under all alternatives.

• Although the potential for noise-based disturbance to individuals within important habitat ranges 

from 8 to 9 percent, and individuals within buffered activity centers ranges from 11 to 12 

percent, under all of the alternatives, the percentage of habitats impacted would actually be lower 

considering that the concentration of OSV use is not equal across the landscape; 30 percent of 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

225

buffered goshawk activity centers fall within 0.5 mile of a groomed trail or OSV staging area, 

the highest OSV use areas. 

• OSV-related noise-based disturbance would overlap with only the early part of the February 15 

through September 15 goshawk breeding season.

• OSV use is most common on trails and once OSV trail grooming season ends on March 31, trail 

use declines by roughly 50 percent. As a result, the possibility of direct and indirect effects to 

goshawk activity centers within 0.25 mile of groomed trails would decrease by an estimated 50 

percent after March 31 for all alternatives.

• The potential for OSV collision with individual northern goshawks is very low.

Bats

Fringed Myotis (Myotis thysanodes)

Species Account

Most Myotis thysanodes in California are referable to M. t. thysanodes; populations in the 

northwestern part of the state (Humboldt, Siskiyou, and Shasta Counties) have recently been placed 

in the new subspecies, M. t. vespertinus (Manning and Jones 1988), although relatively few 

specimens have been examined and the boundary between subspecies has not been clearly 

delineated.

In California, the species is found the length of the state, from the coast (including Santa Cruz 

Island) to over 1,800 meters (5,900 feet) in the Sierra Nevada. Records exist for the high desert and 

east of the Sierra Nevada. However, the majority of known localities are on the west side of the 

Sierra Nevada. Museum records suggest that while M. thysanodes is widely distributed in California, 

it is rare everywhere. Available museum records offer documentation for only six maternity sites: 

two in Kern County (including the type locality at Old Fort Tejon), and one each in Marin, Napa, 

Tuolumne, and Tulare counties. Investigation of four of these sites since 1990 has shown that while 

the roosts are still available, this species is no longer present at any of these sites.

Habitat Status

M. thysanodes occurs in xeric woodland (oak and pinyon-juniper most common) (Cockrum and 

Ordway 1959, Hoffmeister and Goodpaster 1954, Jones 1965, O’Farrell and Studier 1980, Roest 

1951), hot desert-scrub, grassland, sage-grassland steppe, spruce-fir, mesic old growth forest, 

coniferous and mixed deciduous/coniferous forests (including multi-aged sub-alpine, Douglas-fir, 

redwood, and giant sequoia) (O’Farrell and Studier 1980, Pierson and Heady 1996, Weller and Zabel 

2001).

Although nowhere common, the species occurs primarily from sea level to approximately 3,900 to 

6,900 feet (O’Farrell and Studier 1980) with an isolated record from 9,500 feet in New Mexico 

(Barbour and Davis 1969). A lack of records makes it difficult to assess habitat preferences for this 

species in California. Orr (1956), in reviewing specimens held at the California Academy of 

Sciences, notes two localities from the coastal region (Carmel in Monterey County and Woodside in 

San Mateo County). More recently, records have accumulated from the upper Sacramento River 

(Rainey and Pierson 1996).
Over-snow Vehicle Use Designation

Tahoe National Forest

226

Roosting Habitat

Studies conducted in California, Oregon, and Arizona, have documented that M. thysanodes roosts in 

tree hollows, particularly in large conifer snags (Cross and Clayton 1995, Chung-MacCoubrey 1996, 

Rabe et al. 1998, Weller and Zabel 2001). M. thysanodes is also known to use a variety of roost sites, 

including rock crevices (Cryan 1997), caves (Baker 1962, Burt 1934, Commissaris 1961, Easterla 

1966, 1973), mines (Cahalane 1939, Cockrum and Musgrove 1964), buildings (Barbour and Davis 

1969, Musser and Durrani 1960, O’Farrell and Studier 1980, Orr 1956, Studier 1968), and bridges. It 

is also one of the species thought to be most reliant on abandoned mines (Altenbach and Pierson 

1995).

M. thysanodes is a colonial roosting species. Colonies can be up to 2,000 individuals (Barbour and 

Davis 1969). Within buildings, this species tends to roost in the open in tightly packed clusters,

mostly using the sides of ceiling joists (O’Farrell and Studier 1980). Any of these types of structures 

are used as both day and night roosts (Barbour and Davis 1969). Barbour and Davis (1969) noted 

that this species was readily captured at the entrances to night roosts in buildings, mines, and caves.

In a 5-year study on the upper Sacramento River, M. thysanodes, though one of the least commonly 

encountered bats, was more readily detected at bridge night roosts than in netting surveys conducted 

over water (Rainey and Pierson 1996).

Foraging Habitat

M. thysanodes often forages along secondary streams, in fairly cluttered habitat. It also has been 

captured over meadows (Pierson et al. 2001). Limited information is available on diet. Relatively 

heavy tooth wear on animals examined in a 5-year study on the Sacramento River suggests that in 

that area the species feeds primarily on heavy-bodied insects, such as Coleopterans and Hemipterans.

Reproduction

Maternity roosts have been found in sites that are generally cooler and wetter than is typical for most 

other Vespertilionids. Recent radio-tracking studies in the forested regions of northern California 

have shown that this species forms nursery colonies in predominantly early to mid-decay stage, 

large-diameter snags 23 to 66 inches dbh) (Weller and Zabel 2001).

Mating occurs in the fall following break-up of the maternity colony. Ovulation, fertilization, and 

implantation occur from April to May and are followed by a gestation of 50 to 60 days. One young is 

born from May to July, capable of flight in 16 days, and volant within 20 days.

Migration and Hibernation

Winter behavior is even more poorly understood than summer behavior. M. thysanodes is thought to 

migrate short distances to lower elevations or more southern areas (O’Farrell and Studier 1980).

Scattered winter records suggest, however, that the species does not complete long-distance 

migrations, and like many species in the more temperate parts of California, may be intermittently 

active throughout the winter (O’Farrell and Studier 1980). The species has been found hibernating in 

buildings and mine tunnels along the coast in the San Francisco Bay area and in the coast range north 

of San Francisco.

Threats

Anthropogenic Roosts

Although M. thysanodes does not occur in urban areas, it has often been found in buildings in rural 

and semi-rural settings (e.g., wineries, Hearst Castle, Big Bear attic, Bale Grist Mill State Historic 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

227

Park). These colonies are typically at high risk for negative human interactions. Urban expansion 

often leads to removal of older buildings that can provide roosts. Newer buildings generally do not 

provide suitable roosting habitat. Intervention by pest control operators and public health 

departments can result in the elimination of many roost sites.

Direct and indirect Effects

Public OSV use on the Tahoe National Forest would not change the habitat for fringed bat as no 

habitat modifications are anticipated 

Very little is known about the wintering behavior of fringed myotis bats. Some limited migration to 

lower elevation may occur. However, if fringed myotis remain on the landscape in winter, there is a 

low likelihood that behavior of individuals could be modified by the noise or disruption associated 

with OSV use or grooming of OSV trails. This would be entirely dependent on the location of the 

winter roost in proximity to a bridge, building, cavity, mine, or tree. Since there are no known winter 

roosts on the Tahoe, noise cannot be mitigated should there be a noise impact from OSV activities. 

Should OSV activities create a temporary disturbance, breeding could be impacted, however, it 

would not preclude breeding at a later time. There should be no impact to the maternal roosts, as they 

would start in April or May, following snowmelt.

Fringed myotis bats drink water from streams or lakes when they emerge from roosts. In addition, 

they forage in riparian areas and meadows. Emissions from OSVs, particularly two-stroke engines on 

snowmobiles, release pollutants like ammonium, sulfate, benzene, PAHs, and other toxic compounds 

that are stored in the snowpack; during spring snowmelt runoff, these accumulated pollutants are 

released and may be delivered to surrounding waterbodies (USDA Forest Service National Core 

BMP Rec-7: Over-Snow Vehicle Use; please refer to the project hydrology report for additional 

information). However, the minimum cross-country snow depth of 12 inches for all of the action 

alternatives is expected to be adequate to protect aquatic and riparian habitats from measurable 

impacts to vegetation or water quality (McNamara 2017).

Cumulative Effects

M. thysanodes habitat would have minimal overlap with areas open to Christmas tree cutting and 

firewood cutting (annually between November 1 and December 31) and OSV trail grooming season 

(beginning December 26), minimizing possible disturbance or displacement of roosting bats. Use of 

roads within fringed myotis bat habitats after the March 31 termination date of the Forest Order 

closing roads for exclusive OSV use can contribute additional disturbance during the early part of the 

M. thysanodes breeding season. There is a slight possibility of an additive effect of vehicle fluids 

from wheeled vehicles used to access firewood and Christmas trees, as well as from the use of 

wheeled vehicles during the overlap season between OSVs and wheeled vehicles, to enter 

waterways, modifying pallid bat prey/food base. However, the risk for this impact is low because 

vehicle use does not occur in waterways and fluids would not normally reach waterways.

In general, most non-motorized winter recreation occurs along designated trails, and individual bats 

would either avoid roosting in those areas, if too great a disturbance, or habituate to the noise.

Similar activities on State and private lands may impact habitat availability outside of National 

Forest System lands and may increase disturbance locally. However, the potential for this type of 

disturbance is unknown. In summary, ongoing and reasonably foreseeable actions may be additive 

locally to individual bats, but are not expected to contribute substantial impacts to those discussed 

for the project under any of the alternatives.
Over-snow Vehicle Use Designation

Tahoe National Forest

228

Determination Statement

All alternatives of the Tahoe National Forest Over-snow Vehicle Use Designation Project may impact 

individuals, but are not likely to lead to a loss of viability or a trend toward Federal listing for 

fringed myotis in the Forest Plan area based on the following:

• Proposed actions would not physically modify fringed myotis bat habitat.

• Proposed actions would generally occur when the species is hibernating and is generally 

inactive. However, individuals that emerge to forage during warmer weather could experience 

missed feeding when snow grooming activities occur during the early evening. 

• Depending upon the location of winter roost structures with respect to OSV use, individual bats 

within winter roosts could be disturbed by noise associated with OSVs and human presence, and 

missed breeding attempts could result.

• The low risk of modification of the prey/food base or impact on drinking water quality from oil, 

gas, or other vehicle fluids entering waterways would be mitigated by the 12-inch minimum 

snow depth that would protect aquatic and riparian habitats from measurable impacts to 

vegetation or water quality.

Pallid Bat (Antrozous pallidus)

Species Account

Pallid bat has been documented on the Tahoe National Forest.

Habitat Status

A. pallidus occurs in a number of habitats ranging from rocky arid deserts to grasslands into midelevation mixed deciduous/coniferous forests. In California, they are most commonly found in lowelevation desert washes, western sycamore (Plantanus racemosa) open riparian habitat, coast live 

oak (Quercus agrifolia) and valley oak (Q. lobata) savannah, mid-elevation black oak (Quercus 

kelloggii) and mixed deciduous/coniferous forest (black oak, incense cedar (Libocedrus decurrens) 

and ponderosa pine (Pinus ponderosa) habitat (Barbour and Davis 1969, Johnston et al. 2006, Orr 

1954, Pierson et al. 2001, Pierson et al. 2002, Rainey and Pierson 1996). It is also associated with 

both coast redwood and giant sequoia forests (Pierson and Heady 1996, Orr 1954, Rainey et al. 

1992).

Roosting Habitat

Tree roosting appears to be preferred in the forested regions of northern California, and has been 

documented in large conifer snags (e.g., incense cedar, ponderosa pine, sugar pine) (Baker et al. 

2008, Johnston and Gworek 2006), inside basal hollows of redwoods (Orr 1954, Rainey et al. 1992) 

and giant sequoias (Pierson and Heady 1996), and bole cavities in oaks and other trees (e.g.,

cottonwood, cypress) (Hall 1946, Orr 1954, Pierson et al. 2004, Rainey and Pierson 1996).

Compared to some other California bat species, A. pallidus are relatively intolerant of disturbance 

(O'Shea and Vaughan 1977, Lewis 1996, Johnston et al. 2004) and may abandon a roost when 

disturbed. Lewis (1996) noted that distances between day and nighttime roosts were usually less than 

200 meters, but ranged from 40 to 1,850 meters.

This is one of the species most likely to be found night-roosting under bridges (Barbour and Davis 

1969, Johnston et al. 2004, Pierson et al. 2001), but it can also be found in shallow caves, cliff 

overhangs, and other human-made structures (Hermanson and O'Shea 1983, Lewis 1994). Lewis 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

229

(1994) also noted that bridges used by pallid bats as night roosts were wooden, or concrete girder.

Pallid bats show a higher fidelity toward night roosts than day roosts (Lewis 1994). Night roosts are 

typically located within 1 to 2 kilometers of the day roost. When using anthropogenic roosts in 

northern California, reproductive female A. pallidus generally occupy maternity roosts in April or 

May, and move to winter roosts in September, October, or even later if weather is moderate.

Foraging Habitat

Pallid bats forage close to the ground and vegetation in desert washes, open grassland, oak savannah, 

and/or forest with limited understory (e.g., ponderosa pine parkland or granite slabs with sparse 

vegetation) (Hermanson and O'Shea 1983). Johnston et al. (2006) found that male and female 

A.pallidus pacificus foraged intermittently through the winter months along and in riparian corridors 

with western sycamore (Plantanus racemosa), California bay (Umbellularia californica), and coast 

live oak (Quercus agrifolia) within canyon bottoms in central California; and during summer 

months, females and males foraged along ridges with grasslands, high open meadows and oak 

savannah habitats. Johnston and Gworek (2006), and Baker et al. (2008) determined that pallid bats 

frequently foraged on logging roads and in open and semi-open short grass meadows in the northern 

Sierra Nevada. Foraging appears to be concentrated in two periods – one just after emergence and 

one prior to returning to the roost (Hermanson and O'Shea 1983).

Lewis (1996) recorded distances of between 1 and 4 kilometers (0.6 to 2.5 miles) traveled between 

roost sites and foraging areas and Johnston et al. (2006) found similar distances (0.2 to

4.0 kilometers) for males and females during winter months.

Reproduction

Pallid bats are gregarious, and often roost in colonies of between 20 and several hundred individuals.

Males and females congregate in a central winter roost often associated with smaller satellite roosts 

in late fall and winter months (Johnston et al. 2006) when breeding occurs (Hermanson and O'Shea 

1983). During spring months, pregnant females leave the winter roost and gather in summer 

maternity colonies (Johnston et al. 2006), with parturition generally occurring between May and 

July, depending on local climate (Barbour and Davis 1969). Males often leave the winter roost and 

use a variety of solitary roosts, but they sometimes form a bachelor colony (Johnston et al. 2006).

Maternity colonies generally form in early April (Barbour and Davis 1969) and disband between 

August and October (Hermanson and O'Shea 1983, Lewis 1994.

Migration/Hibernation

Pallid bats are relatively inactive during the winter; however, Johnston et al. (2006) found that males 

and females foraged intermittently throughout the winter months, in central California.

They are not known to migrate long distances (Barbour and Davis 1969), and Johnston et al. (2004) 

determined that the primary female/male winter roost of a large colony in central California was 

approximately 1 mile from the primary maternity colony roost. During January and February, pallid 

bats foraged about once every six nights, at temperatures down to 4 degrees C (39 degrees F) and on 

rainy nights.

Threats

Anthropogenic Roosts

Due to their propensity for using a wide range of buildings as well as bridges, their highly visible 

roosting habits, urine stains and odor, as well as visible insect prey remains at night roosts, these bats 
Over-snow Vehicle Use Designation

Tahoe National Forest

230

are highly susceptible to negative human contact. Because pallid bats frequently roost in buildings 

and bridges, display considerable roost loyalty in such roosts, and are often found roosting together 

with T. brasiliensis and M. yumanensis, two species that form large colonies (several hundreds to 

thousands), often where they are highly visible (e.g., open rafters), they are frequently subjected to 

vandalism, exclusion (humane or otherwise), even illegal poisoning.

Direct and indirect Effects

OSV use and related activities on the Tahoe National Forest would not change the habitat for pallid 

bat, as no habitat modifications are anticipated. Due to the behavior of pallid bats that they can be 

seen in winter on warmer nights (39 degrees F), or males moving between winter roosts, or an 

occasional feeding (once every six nights), there is a low likelihood that pallid bat behavior could be 

modified by OSV noise or disruption of grooming trails for OSV use. 

OSV noise could cause disturbance at the winter roost. This would be entirely dependent on the 

location of the winter roost in proximity to a bridge, building, cavity, mine or tree. Since there are no 

known winter roosts on the Tahoe, no reduction of noise can be mitigated should there be a noise 

impact from OSV activities. Should OSV activities have a temporary disturbance, breeding could be 

impacted; however, it would not preclude breeding at a later time. There should be no impact to the 

maternal roosts, as they would start in April or May, following snowmelt.

Pallid bats forage on invertebrates in areas with riparian and/or aquatic environments. Emissions 

from OSVs, particularly two-stroke engines on snowmobiles, release pollutants like ammonium, 

sulfate, benzene, PAHs, and other toxic compounds that are stored in the snowpack; during spring 

snowmelt runoff, these accumulated pollutants are released and may be delivered to surrounding 

waterbodies (USDA Forest Service National Core BMP Rec-7: Over-Snow Vehicle Use; please refer 

to the project hydrology report for additional information). However, the minimum cross-country 

snow depth of 12 inches under all of the action alternatives is expected to be adequate to protect 

aquatic and riparian habitats from measurable impacts to vegetation or water quality (McNamara 

2016).

Cumulative Effects

Cumualtive effects for the pallid bat is the same as fringed myotis (Myotis thysanodes).

Determination Statement

All alternatives of the Tahoe National Forest Over-snow Vehicle Use Designation Project may impact 

individuals, but are not likely to lead to a loss of viability or a trend toward Federal listing for pallid 

bat in the Forest Plan area based on the following:

• Proposed actions would not physically modify pallid bat habitat.

• Proposed actions would generally occur when the species is hibernating and is typically inactive.

However, individuals that emerge to forage during warmer weather could experience missed 

feeding when snow grooming activities occur during the early evening.

• Depending upon the location of winter roost structures with respect to OSV use, individual bats 

within winter roosts could be disturbed by noise associated with OSVs and human presence and 

missed breeding attempts could result.

• The low risk of modification of the prey/food base from oil, gas, or other vehicle fluids entering 

waterways would be mitigated by the 12-inch minimum snow depth that would protect aquatic 

and riparian habitats from measurable impacts to vegetation or water quality.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

231

Townsend’s Big-eared Bat (Corynorhinus townsendii)

Species Account

There are historical and fairly recent (1997) records of Townsend’s big-eared bat near the Tahoe 

National Forest as well as a documented maternity and hibernaculum in lava tubes on the Hat Creek 

Ranger District.

Habitat Status

C. townsendii occurs from the inland deserts to the cool, moist coastal redwood forests; in oak 

woodlands of the inner coast range and Sierra Nevada foothills; and lower- to mid-elevation mixed 

coniferous-deciduous forests. Distribution is patchy, and strongly correlated with the availability of 

caves and cave-like roosting habitat, with population centers occurring in areas dominated by 

exposed, cavity-forming rock and/or historic mining districts (Genter 1986, Graham 1966, 

Humphrey and Kunz 1976, Kunz and Martin 1982, Pierson and Rainey 1996). Its habit of roosting 

on open surfaces makes it readily detectable, and it is often the species most frequently observed 

(commonly in low numbers) in caves and abandoned mines throughout its range. 

Roosting Habitat

C. townsendii prefers open surfaces of caves or cave-like structures, such as mines (vertical and 

horizontal) (Barbour and Davis 1969, Graham 1966, Humphrey and Kunz 1976). It has also has been 

reported in such structures as buildings, bridges, and water diversion tunnels that offer a cavernous 

environment (Barbour and Davis 1969, Dalquest 1947, Howell 1920, Kunz and Martin 1982, 

Pearson et al. 1952, Perkins and Levesque 1987, Brown et al. 1994, Pierson and Rainey 1996).

Roosting structures often contain multiple openings. It seems to prefer dome-like areas, possibly 

where heat or cold is trapped (warm pockets for maternal roosting, cold pockets for hibernation). It 

has also been reported in rock crevices and large hollow trees (Fellers and Pierson 2002).

Specific roosts may be used only one time of year or may serve many different functions throughout 

the year (i.e., maternal, hibernation, dispersal, bachelor, breeding, etc.). Roosting surfaces often 

occur in twilight conditions; however, some have been located very deep inside caves or mines.

There is evidence that maternity colonies may use multiple sites for different stages (pregnancy, 

birthing, or rearing) (Sherwin et al. 2000). Males remain solitary during the maternity season.

C. townsendii is very sensitive to human disturbance; however, in some instances it can habituate to 

reoccurring and predictable human activity.

Foraging Habitat

Foraging associations include edge habitats along streams and areas adjacent to and within a variety 

of wooded habitats (Brown et al. 1994, Fellers and Pierson 2002, Pierson et al. 2002). Recent radiotracking and light-tagging studies have found C. townsendii foraging in a variety of habitats. Brown 

et al. (1994) showed that on Santa Cruz Island in California, they avoided the lush introduced 

vegetation near their day roost, and traveled up to 3 miles to feed in native oak and ironwood forest.

Radio-tracking and light-tagging studies in northern California found C. townsendii foraging within 

forested habitat (Rainey and Pierson 1996). C. townsendii has been known to travel up to 15 miles 

from roost sites while foraging (Dobkin et al. 1995). They forage as long as weather permits in the 

fall, and are periodically active in winter (Pierson et al. 1991). 
Over-snow Vehicle Use Designation

Tahoe National Forest

232

Reproduction

C. townsendii is a colonial species with maternity aggregations forming between March and June 

(based on local climate and latitude). Colony size ranges from a few dozen to several hundred.

Mating generally takes place in both migratory sites and hibernacula between September or October 

and February. Young bats are capable of flight at 2.5 to 3 weeks of age and are fully weaned at 

6 weeks (Pearson et al. 1952). Nursery colonies start to disperse in August about the time the young 

are weaned, and break up altogether in September and October (Pearson et al. 1952, Tipton 1983).

Pearson et al. (1952) estimated annual survivorship at about 50 percent for young, and about 

80 percent for adults. Band recoveries have yielded longevity records of 16 years, 5 months 

(Paradiso and Greenhall 1967).

Migration/Hibernation

C. townsendii is a relatively sedentary species, for which no long-distance migrations have been

reported (Barbour and Davis 1969, Humphrey and Kunz 1976, Pearson et al. 1952). The longest

movement known for this species in California is 20 miles (Pearson et al. 1952). There is some 

evidence of local migration, perhaps along an altitudinal gradient.

Hibernation sites are generally caves or mines (Pearson et al. 1952, Barbour and Davis 1969), 

although animals are occasionally found in buildings (Dalquest 1947, E. Pierson pers. obs.). Winter 

roosting is typically composed of mixed-sexed groups from a single individual to several hundred or 

several thousand, however, behavior varies with latitude. In areas with prolonged periods of nonfreezing temperatures, C. townsendii tends to form relatively small hibernating aggregations of 

single to several dozen individuals (Barbour and Davis 1969, Pierson et al. 1991, Pierson and Rainey 

1996). Larger aggregations (75 to 460) are confined to areas that experience prolonged periods of 

freezing temperatures (Pierson and Rainey 1996). Studies in the western United States have shown 

that C. townsendii selects winter roosts with stable, cold temperatures, and moderate air flow 

(Humphrey and Kunz 1976, Kunz and Martin 1982). Temperature appears to be a limiting factor in 

roost selection. Recorded temperatures in C. townsendii hibernacula range from minus 2.0 to 13.0

degrees C (28 to 55 degrees F) (Humphrey and Kunz 1976, Genter 1986, Pearson et al. 1952, Pierson 

et al. 1991, Twente 1955), with temperatures below 10 degrees C (50 degrees F) being preferred 

(Pierson and Rainey 1996). The period of hibernation is shorter at lower elevations and latitudes.

Threats

Surveys conducted by Pierson and Rainey (1996) show marked population declines for both 

subspecies in California. This species has been petitioned for listing as threatened or endangered 

status in the state. Over the past 40 years, there has been a 52 percent loss in the number of maternity 

colonies, a 45 percent decline in the number of available roosts, a 54 percent decline in the total 

number of animals, and a 33 percent decrease in the average size of remaining colonies for the 

species as a whole statewide. The status of particular populations is correlated with amount of 

disturbance to or loss of suitable roosting sites. The populations that have shown the most marked 

declines are along the coast, in the Mother Lode country of the western Sierra Nevada foothills, and 

along the Colorado River.

The combination of restrictive roost requirements and sedentary behavior suggests that C. townsendii

is roost limited, and that roost loss, through disturbance or destruction, has been primarily 

responsible for population declines in most areas. Although fire, winter storms, or general 

deterioration are sometimes responsible, in all but 2 of 39 documented cases, roost loss in California 

can be directly linked to human activity (e.g., demolition, renewed mining, entrance closure, humaninduced fire, renovation, or roost disturbance). Population declines are most highly correlated with 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

233

roost destruction in the San Francisco Bay area, along the northern coast, and in San Diego County, 

and with roost disturbance in the Mother Lode country and along the Colorado River. 

Anthropogenic Roosts

Although C. townsendii is often found using human-made structures, such as barns, large houses, 

historic buildings, and bridges, they are very sensitive to disturbance, and will readily abandon a day 

roost, particularly a maternity roost, if disturbed. Bats are often not tolerated in historic structures, 

even those that are not open to the public, due to concerns over damage to the historic fabric of a 

building, so even a rare species such as C. townsendii, one that forms relatively small colonies, is 

subject to permanent loss of critical roost habitat. Because C. townsendii is a large cavity-roosting 

species, and not a crevice-roosting species, they will not use bat houses as replacement habitat, so 

loss of structure roosts is highly significant for this species.

Caves

Maternity colonies are impacted by inappropriate cave closures or disturbance during human 

visitation.

The increasing and intense recreational use of caves in California provides the most likely 

explanation for why most otherwise suitable, historically significant roosts are currently unoccupied.

It is well documented that C. townsendii is so sensitive to human disturbance that simple entry into a 

maternity roost can cause a colony to abandon or move to an alternate roost (Pearson et al. 1952; 

Graham 1966; Stebbings 1966; Mohr 1972; Humphrey and Kunz 1976; Stihler and Hall 1993).

Direct and Indirect Effects

OSV use on the Tahoe National Forest would not change the habitat for Townsend’s big-eared bat, as 

no habitat modifications are anticipated 

Very little is known about Townsend’s big-eared bats’ wintering behavior. Some limited migration to

lower elevation may occur. However, if Townsend’s big-eared bats remain on the landscape in 

winter, there is a low likelihood that their behavior could be modified by the noise or disruption 

associated with OSV use or grooming of OSV trails. This would be entirely dependent on the 

location of the winter roost in proximity to a bridge, building, cavity, mine or tree. Since there are no 

known winter roosts on the Tahoe, no reduction of noise can be mitigated should there be a noise 

impact from OSV. Should OSV activities have a temporary disturbance, breeding could be impacted, 

however it would not preclude breeding at a later time. There should be no impact to the maternal 

roosts, as they would start in April or May, following snowmelt.

Townsend’s big-eared bats forage in riparian areas and meadows outside of the hibernation period.

Emissions from OSVs, particularly two-stroke engines on snowmobiles, release pollutants like 

ammonium, sulfate, benzene, PAHs and other toxic compounds that are stored in the snowpack; 

during spring snowmelt runoff, these accumulated pollutants are released and may be delivered to 

surrounding waterbodies (USDA Forest Service National Core BMP Rec-7: Over-Snow Vehicle Use; 

refer to the project hydrology report for additional information). However, the minimum crosscountry snow depth of 12 inches under all of the action alternatives is expected to be adequate to 

protect aquatic and riparian habitats from measurable impacts to vegetation or water quality 

(McNamara 2017).

Cumulative Effects

Cumualtive effects for Townsend’s big-eared bats is the same as fringed myotis (Myotis thysanodes).
Over-snow Vehicle Use Designation

Tahoe National Forest

234

Determination Statement

All alternatives of the Tahoe National Forest Over-snow Vehicle Use Designation Project may impact 

individuals, but are not likely to lead to a loss of viability or a trend toward Federal listing for 

Townsend’s big-eared bat in the Forest Plan area based on the following:

• Proposed actions would not physically modify Townsend’s big-eared bat habitat.

• Proposed actions would generally occur when the species is hibernating and is typically inactive.

• Depending upon the location of winter roost structures with respect to OSV use, individual bats 

within winter roosts could be disturbed by noise associated with OSVs and human presence, and 

missed breeding attempts could result.

• The low risk of modification of the prey/food base from oil, gas, or other vehicle fluids entering 

waterways would be mitigated by the 12-inch minimum snow depth that would protect aquatic 

and riparian habitats from measurable impacts to vegetation or water quality. 

Species that Utilize Riparian or Wetland Habitats

Bald Eagle (Haliaeetus leucocephalus)

Species Account

The bald eagle, (Haliaeetus leucocephalus), was federally de-listed on August 8, 2007 (Federal 

Register Vol. 72, No. 130, pp. 37346-37372) and then placed on the USDA Forest Service Region 5 

Regional Forester’s sensitive species list. 

This species occurs and winters throughout California, except in desert areas. Migratory individuals 

from northern and northeastern parts of the state arrive between mid-October and December, and 

remain until March or early April. Most bald eagle breeding in California occurs in the northern 

counties (Butte, Lake, Tahoe, Modoc, Plumas, Shasta, Siskiyou, and Trinity Counties), typically at 

low elevations; breeding in the high Sierra Nevada is rare (USDA Forest Service 2001). 

Habitat Status

Bald eagles winter near lakes, reservoirs, riverine, and marsh habitats. They breed mainly in the 

northern portion of the state near coastlines, rivers, large lakes or streams that support an adequate 

food supply. Bald eagles require open water with juxtaposed mature trees or steep cliffs for nesting, 

perching, foraging, and roosting (Bent 1961 in Murphy and Knopp 2000). They often nest in mature 

or old-growth trees; snags (dead trees); cliffs; rock promontories; rarely on the ground; and with 

increasing frequency on human-made structures such as power poles and communication towers. On 

the Tahoe National Forest, bald eagles initiate breeding in January. Incubation begins in late 

February to mid-March with the nesting period extending as late as the end of June (USDA Forest 

Service 2010).

Bald eagles are usually monogamous and pair for life, though repairing may occur if either of the 

pair dies. The mating season varies by latitude. Pair initiation begins in January and egg-laying 

occurs in early May. Breeding home ranges vary substantially by location from 58 acres in Alaska to 

5 acres in Arizona. Migration distances of up to 1,712 miles have been recorded. Fidelity to 

wintering grounds is strong (summarized in USDA Forest Service 2001).
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

235

There are 18 nest sites (565 acres) buffered by 660 feet33and 22,022 acres of bald eagle reproductive 

habitat34 on National Forest System lands within the Tahoe National Forest boundary.

Threats

The Recovery Plan for the Pacific Bald Eagle (USFWS 1986) states that the main threats to this 

species in Sierra Nevada Mountains (Zone 28) are disturbance at wintering grounds and loss of 

potential nesting habitat to logging or development. The Plan’s proposed management directions are 

maintenance of winter habitat and evaluation of reintroduction/expansion of ‘breeders.’ The most 

urgent site-specific task (1.3211) identified for the Forest Service in the Sierra Nevada Mountains is 

to prohibit logging of known nest, perch, or winter roost trees (USFWS 1986). 

Bald eagles are also sensitive to human or recreation disturbance. Numerous studies have reported 

that eagles avoid or are adversely affected by human disturbance during the breeding period, which 

may result in nest abandonment and reproductive failure (Stalmaster and Newman 1978, Andrew and 

Mosher 1982, Fraser et al. 1985, Knight and Skagen 1988, Buehler et al. 1991, Grubb and King 

1991, Chandler et al. 1995). The response of bald eagles to human activities is variable. Individual 

bald eagles show different thresholds of tolerance for disturbance. This variability may be related to 

a number of factors, including visibility, duration, noise levels, extent of the area affected by the 

activity, prior experiences with humans, and tolerance of the individual nesting pair (USFWS 2007). 

Forested habitats can mute noise generated by vehicles and screen the vehicle from sight. 

Disturbance effects are greatest during nest building, courtship, egg laying, and incubation. However, 

disruption, destruction, or obstruction of roosting and foraging areas can also negatively affect bald 

eagles. Disruptive activities in or near eagle foraging areas can interfere with feeding, reducing 

chances of survival or productivity (number of young successfully fledged). Migrating and wintering 

bald eagles often congregate at specific sites, usually in mature trees where the eagles are somewhat 

sheltered from the wind and weather, for purposes of feeding and sheltering because of their 

proximity to sufficient food sources. Human activities near or within communal roost sites may 

prevent eagles from feeding or taking shelter, especially if no other undisturbed and productive 

feeding and roosting sites are available.

Stalmaster and Newman (1978) found that wintering bald eagles were adversely affected by human 

disturbance and distribution patterns were significantly changed by human activity. Eagles were 

displaced in areas of high human activity and moved to areas of lower human activity. Flush 

distances were lower when the disturbance was on land than in the water and lower still if the eagle 

couldn’t see the cause of the disturbance. 

Additional studies indicate that animals, including bald eagles, infrequently demonstrated active 

responses to OSVs and associated human presence (NPS 2013). In a study based on approximately 

5,688 interactions35 over four winters between groups of wildlife and groups of snowmobiles and/or 

snowcoaches, White et al. (2009) found the following observed responses of bald eagles to OSV use: 

no apparent response (17 percent), look-resume (64 percent), alert (9 percent), travel (4 percent), 

flight (6 percent), and defensive (0 percent). Based on these findings, it would appear that eagles 

 33 660 foot nest site buffers based on USFWS (2007) 34 Ponderosa pine [CWHR (2014) types 5S, 5P, 5M, 5D)] and Sierran mixed conifer and white fir [CWHR (2014) types 5S, 

5P, 5M, 5D, and 6)] within 1 mile of waterbodies and major rivers. Buffered nest sites are not included in total to prevent 

double counting with nest site analysis.

35 An interaction sampling unit was defined as the interaction between a group of OSVs and associated humans and a group 

of bison or elk within 1,500 feet (500 meters) of the road.
Over-snow Vehicle Use Designation

Tahoe National Forest

236

have become desensitized to OSV use and other human disturbance in the park during winter to 

some extent (NPS 2013).

White et al. (2009) also assessed the relationship between wildlife behavioral responses and factors 

including wildlife group size or distance from road, interaction time, group size of snowmobiles or 

snowcoaches, type of habitat, and cumulative winter OSV traffic. For bison, elk, swans, and bald 

eagles, the odds of a movement response (travel, flight) decreased with increasing distance of the 

animals from the road.

National Bald Eagle Management Guidelines (USFWS 2007) include a buffer of 100 meters 

(330 feet) for off-road vehicle use, including snowmobiles, in forested landscapes and/or variable 

terrain, and 200 meters (660 feet) in open landscapes where line of sight to nest trees may be a 

concern.

Direct and Indirect Effects

Resource indicators and measures (FSH 1909.15, 12.5) used in this analysis to measure and disclose 

effects to bald eagle are listed in table 77.

Table 77. Resource indicators and measures for assessing effects to bald eagles

Resource Indicator and 

Effect

Measure

(Quantify if possible)

Alternatives 

1 and 2

Alternative 

3

Alternative 

4

Alternative 

5

Potential for disturbance to 

individuals from noise and 

increased human presence, 

injury or mortality of individuals

Acres of high value 

reproductive habitat 

impacted by OSV use

4,124 4,748 4,259 4,124

Potential for disturbance to 

individuals from OSV use and 

increased human presence or 

injury or mortality of individuals

Acres of buffered bald 

eagle nests impacted by 

OSV use

18 18 18 18

The majority of associated risk factors within wetland and riparian habitats apply to roads and trails 

and primarily include the following direct effects (Gaines et al. 2003): site disturbance and possible

injury or mortality to individuals from vehicle collisions. Site disturbance includes (1) displacement 

or avoidance by populations or individual animals away from human activities; and (2) disturbance 

and displacement of individuals from breeding or rearing habitats. Possible injury or mortality to 

individuals from vehicle collision: The likelihood of a collision between snow grooming equipment 

and bald eagles is extremely low because the equipment travels slowly (3 to 6 mph) and snow 

grooming occurs at night when eagles are roosting. There is an increased likelihood of collision with 

OSVs due to higher frequency of OSV use and higher speeds, but the risk is still very low. OSV 

proposed actions would not physically modify any suitable bald eagle habitat within the project area.

Comparison of the Alternatives

Table 78 and table 79 show and compare, by alternative, the amount of buffered bald eagle nest sites 

and high value reproductive habitat, respectively, with the potential for direct and indirect effects 

(disturbance, injury, or mortality) from OSV use and related activities. 

Nine percent of eagle nest sites buffered by 660 feet are designated and conducive to OSV use under 

all alternatives. Similarly, 3 percent of buffered nest sites are currently designated and conducive to 

OSV use for all alternatives. The risk of OSV-related impacts to bald eagle, including noise-based 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

237

disturbance or injury/mortality, would be most likely to occur in those areas conducive to OSV use. 

In addition, of the 9 percent of buffered activity centers and the 3 percent of buffered activity centers 

open to and conducive to OSV use, high OSV use is concentrated within 0.5 mile of snowmobile 

staging areas, on and within 0.5 mile of groomed trails, and in meadows within 0.5 mile of a 

designated OSV trail, so the majority of OSV use occurs within in an even smaller percentage of 

each of those habitats; no nest sites are located within high OSV-use areas and only 1 nest site is 

located within 1.5 miles of designated OSV trails, where moderate use would be expected to occur.

The Fish and Wildlife Service (2007) recommended nest buffer for off-road vehicle use to prevent 

impacts to nesting bald eagles is 660 feet. In addition, bald eagles and their habitat are subject to the 

Bald Eagle Protection Act of 1940 that prohibits disturbance to bald eagles that results in injury, a 

decrease in productivity, or nest abandonment. The forest would use the results of ongoing inventory 

and monitoring of bald eagle nest sites to determine whether disturbance is occurring and if changes 

in management are necessary

Table 78. Acres of bald eagle nest sites, buffered by 660 feet by alternative

Alternative 

1

Alternative 

2

Alternative 

3

Alternative 

4

Alternative 

5

Designated for OSV Use 29 29 29 29 29

Designated for OSV use and 

conducive to OSV use

18 18 18 18 18

(3%)

Under alternatives 3, 4, and 5, reproductive habitat (9 percent) could be impacted by OSV use

similar to alternative 1. Under alternative 2, above the 5,000-foot elevation, 4 percent of the 

reproductive habitat could be impacted by OSV use. Under all alternatives, only one eagle nest site is 

located within OSV moderate use areas and this nest site is located 1.3 miles away of any groomed 

OSV trails. No bald eagle nest sites are within 660 feet of high OSV use areas under all alternatives. 

Therefore, disturbance impacts to breeding bald eagles are expected to be low under any of the 

alternatives.

Table 79. Acres of high-value bald eagle reproductive habitat, by alternative

Alternative 

1

Alternative 

2

Alternative 

3

Alternative 

4

Alternative 

5

Designated for OSV use 45,878 30,586 51,913 46,953 45,878

Total acres of high-value bald eagle 

reproductive habitat

45,878 30,586 51,913 46,953 45,878

Designated and conducive to OSV 

use

4,124 1,375 4,748 4,259 4,124

Cumulative Effects

Bald eagle habitat overlaps with areas open to Christmas tree and firewood cutting. There would be 

minimal overlap between the Christmas tree and firewood cutting season (annually between 

November 1 and December 31) and OSV trail grooming season (beginning December 26), and 

disturbance or displacement from this activity would occur outside of the bald eagle breeding season 

under all alternatives. Use of roads within bald eagle habitats after the March 31 termination date of 

the Forest Order closing roads for exclusive OSV use can contribute additional disturbance during 

the early part of the bald eagle breeding season, particularly for nests within 0.25 mile of roads. In 
Over-snow Vehicle Use Designation

Tahoe National Forest

238

general, most non-motorized winter recreation occurs along designated trails, where birds would 

either avoid the area, if too great an impact, or habituate to the noise. Similar activities on State and 

private lands within the forest boundary and within 0.25 mile of bald eagle nests may impact habitat 

outside of National Forest System lands and may increase disturbance locally. However, the potential 

for this type of disturbance is unknown. In summary, ongoing and reasonably foreseeable actions 

may locally increase disturbance to or displacement of bald eagles, but are not expected to contribute 

substantial impacts to those discussed for the project under any of the alternatives.

Determination Statement

Alternatives 1, 2, 3, 4 and 5 of the Tahoe National Forest Over-snow Vehicle Use Designation 

Project may affect individuals, but are not likely to lead to a loss of viability or a trend toward 

Federal listing for bald eagle in the Forest Plan area for the following reasons: 

• OSV proposed actions would not physically modify the structure or composition of suitable bald 

eagle habitat within the project area.

• The forest would use the results of ongoing inventory and monitoring of bald eagle nest sites to 

determine whether disturbance is occurring and if changes in management are necessary, thereby 

minimizing impacts to bald eagle.

• No bald eagle nest sites are within 660 feet of high OSV use areas under any of the alternatives. 

Although one nest site is located with the moderate use area, it is located 1.3 miles away from 

any groomed OSV trails. Therefore, disturbance to any individual is expected to be low.

• The potential for injury or mortality from OSV collision with individual bald eagles is very low

under all of the alternatives.

Great Gray Owl (Strix nebulosa)

Species Account

The great gray owl population estimate for California is fewer than 300 individuals (Wu et al. 2015). 

The present known population is centered in and adjacent to Yosemite National Park. There have 

also been several recent sightings on the Sierra National Forest, including a successful nest site in 

2002. Recent sightings of great gray owls have also been recorded in or near Modoc, Plumas, Tahoe, 

Eldorado, and Toiyabe National Forests. There is one great gray owl PAC on the forest although the 

nest is on private land adjacent to the forest. 

Habitat Status

As described by Beck and Winter (2000), great gray owls (Strix nebulosa) require mid- or latesuccession conifer forests at size class 4 (dominant and co-dominant trees 12 to 23 inches), 

containing large (over 24 inches dbh), broken-top snags in the forest matrix in sufficient numbers (5 

to 6 snags per acre) to provide nest sites. Located suitable nest sites were near (less than 440 yards or 

approximately 400 meters) montane meadows between 2,000 and 8,000 feet in elevation. Forest 

canopy closures are greater than 60 percent in at least some portion of the forest stands adjacent to 

meadows or other natural or managed herbaceous openings (i.e., patch cut regenerated forest). 

Foraging areas include meadows and openings that have sufficient herbaceous cover to support 

pocket gophers and meadow voles; pocket gophers and meadow voles are believed to comprise the 

majority of the owl’s diet (Kalinowski et al. 2014). Likely territories include meadows that total 

10 acres or more adjacent to these mature closed canopy forest stands (Beck and Winter 2000). Van 

Riper et al. (2013) found that human recreational activities seem to have a negative influence on 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

239

great gray owl distribution in Yosemite National Park, particularly in remote natural areas of the 

park, largely avoiding those areas where people are present; in the park, owls primarily use meadows 

with lower levels of human activity. Loss of mature forest habitat for nesting and the degradation of 

montane meadows remain the major sources of habitat loss.

Suitable habitat for the great gray owl is scattered across the Tahoe National Forest. There are 32,062 

acres of great gray owl high-value reproductive habitat36 on National Forest System lands within the 

project area.

Direct and Indirect Effects

Resource indicators and measures (FSH 1909.15, 12.5) used in this analysis to measure and disclose 

effects to great gray owl are listed in table 80.

Resource Indicators and Measures for Assessing Effects to Great Gray Owl

Table 80. Resource indicators and measures for assessing effects to great gray owl

Resource Indicator and 

Effect

Measure

(Quantify if possible)

Alternatives 

1 and 2

Alternative 

3

Alternative 

4

Alternative 

5

Potential for disturbance to 

individuals from noise and 

increased human presence, 

injury or mortality of 

individuals, or habitat 

modification

Acres of highreproductive habitat 

impacted by OSV use 

914 640 924 841

The majority of associated risk factors within wetland and riparian habitats apply to roads and trails 

and primarily include the following direct effects (Gaines et al. 2003): site disturbance and possible 

injury or mortality to individuals from vehicle collisions. Site disturbance includes (1) displacement 

or avoidance by populations or individual animals away from human activities; and (2) disturbance 

and displacement of individuals from breeding or rearing habitats. 

Although great gray owls have not been confirmed nesting on the Tahoe National Forest, they have 

been observed nearby and, over time, could be affected by forest OSV activities. Snowplay in 

meadows may prevent great gray owl use of in or adjacent to those meadows. Like the other raptor 

species under consideration in this analysis, noise-based disturbance to breeding individuals is the 

primary concern. If great gray owls are present on the Tahoe National Forest, the disturbance to 

breeding individuals would be limited to the early portion of the March 1 through August 15 great 

gray owl breeding season that overlaps with the OSV use season.

Owls are nocturnal, whereas the majority of OSV use and associated activities on the Tahoe National 

Forest, with the exception of trail grooming, occur during the daytime, so the risk of collisions of 

OSVs with great gray owls, should they be present, would be negligible and foraging behavior would 

generally not be interrupted. 

 36 Areas less than 440 yards (approximately 400 meters) to montane meadows greater than 10 acres in size and between 

2,000 and 8,000 feet in elevation with forest canopy closures greater than 60 percent (CWHR closure class “D”) in at least 

some portion of the forest stands adjacent to meadows; habitat query includes adjacent meadows that are foraging habitat.
Over-snow Vehicle Use Designation

Tahoe National Forest

240

Effects of noise disturbance would be the same as those noted due to OSV use. In addition, trail 

grooming and night riding could disturb owls that forage at night. Trails are generally located away 

from meadows, but the passage of a trail grooming machine on a trail adjacent to or nearby a 

meadow, may interrupt owl foraging, result in owl prey taking refuge, or cause owls to redirect their 

foraging away from that particular area. However, due to the limited frequency37 and duration of trail 

grooming at any trail segment location, noise disturbance from trail grooming would probably not 

significantly impact breeding or foraging great gray owls. Although night riding could have similar 

impacts to foraging owls, it would be uncommon, because most OSV use on the Tahoe National 

Forest occurs during daytime hours.

Based upon OSV use patterns described in the assumptions section, once OSV trail grooming ends, it 

is estimated that use of those trails declines by 50 percent. Therefore, the direct and indirect effects 

to activity centers within 0.25 mile of groomed trails would decrease substantially after March 31 for 

all alternatives.

Although OSV use or related activities would not physically alter the vegetative structure of spotted 

owl habitat, spotted owl prey species that use the subnivean space could be subject to OSV-related 

impacts from snow compaction, including suffocation or alteration of movement while foraging in 

the subnivean space beneath the snow. The degree of this impact is unknown, but would be more 

likely in areas most conductive to OSV, including meadows used by great gray owls for foraging.

Comparison of the Alternatives

Table 81 displays, by alternative, the acres of great gray owl reproductive habitat, with the potential 

for direct and indirect effects from OSV use and related activities. Ninety-four percent of great gray 

owl reproductive habitat is currently designated for OSV use (alternative 1). However 3 percent is 

designated and conducive to OSV use. OSV-related impacts (noise-based disturbance, snow 

compaction impacting subnivean space of prey species, or injury/mortality) to great gray owls, 

should they be present, would be most likely to occur in those areas conducive to OSV use. In 

addition, of the 3 percent of habitat open to and conducive to OSV use, high OSV use is concentrated 

within 0.5 mile of snowmobile staging areas, on and within 0.5 mile of groomed trails, and in 

meadows within 0.5 mile of a designated OSV trail, so the majority of OSV use occurs within an 

even smaller percentage of each of those habitats. This would be true under the other four 

alternatives. 

Under alternative 2, 2 percent of great gray owl reproductive habitat would be open and conducive to 

OSV use, and under alternatives 3, 4, and 5, 3 percent of great gray owl reproductive habitat would 

be open and conducive to OSV use. In the event that great gray owls are found on the forest, as 

previously noted, the OSV-related noise-based disturbance would overlap with only the early part of 

the March 1 through August 15 great gray owl breeding season. In addition, nest sites could be

impacted would be monitored to determine whether disturbance is occurring and if changes in 

management, including a limited operating period around nest sites, are necessary, thereby 

minimizing impacts to the great gray owl.

 37 Grooming operations at most trail systems currently operate near a maximum level. Trails are prioritized for grooming 

based on visitor use. Grooming on priority trails occurs several times per week and after significant storms. The total hours

of trail grooming occurring expected at each site for an average season vary from 94 annual snowcat hours at Swain 

Mountain to 680 hours at Bogard and Fredonyer on the Lassen National Forest. Snow removal on access roads and 

trailhead parking areas, serving the OSV Program trail systems, occurs several times during storm events, as necessary 

dependent upon weather conditions (California Parks and Recreation 2010).
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

241

Table 81. Acres of high-value great gray owl reproductive habitat with highest potential to be impacted 

by OSV use and related activities, by alternative

Alternative 

1

Alternative 

2

Alternative 

3

Alternative 

4

Alternative 

5

Designated for OSV Use 30,193 21,135 30,193 30,193 30,264

Total acres of high-value great 

gray owl reproductive habitat

30,299 30,299 30,299 30,299 30,793

Designated for OSV use and 

conducive to OSV use

914 640 912 924 841 

Cumulative Effects

Vegetation management and salvage projects are very small in comparison to the OSV use area 

and/or do not overlap with groomed and ungroomed OSV routes or staging areas where the highest 

OSV use occurs. However, limited operating periods required for vegetation management and road 

construction prevent impacts to breeding great gray owls. In addition, vegetation and fuels 

management activities in recent years have included primarily thinned, masticated, and/or burned 

vegetation to reduce the risk of catastrophic wildfires that benefit the great gray owl. These projects 

are usually excluded from larger CWHR types. 

Great gray owl habitat also overlaps with areas open to Christmas tree and firewood cutting. There 

would be minimal overlap between the Christmas tree and firewood cutting season (annually 

between November 1 and December 31) and OSV trail grooming season (beginning December 26), 

and disturbance or displacement from this activity would occur outside of the great gray owl 

breeding season under all alternatives. Use of roads within great gray owl habitats after the March 31 

termination date of the Forest Order closing roads for exclusive OSV use could contribute additional 

disturbance during the early part of the great gray owl breeding season, particularly for nests within 

0.25 mile of roads. However, no great gray owl nests have been identified on the Tahoe National 

Forest. 

In general, most non-motorized winter recreation occurs along designated trails, where birds would 

avoid roosting in the area, if too great a disturbance, or habituate to the noise. Similar activities on 

State and private lands within the forest boundary and within 0.25 mile of great gray owl habitats 

may impact habitat availability outside of National Forest System lands and may increase 

disturbance locally. However, the potential for this type of disturbance is unknown. In summary, 

ongoing and reasonably foreseeable actions could be additive locally to individual great gray owls, 

but are not expected to contribute substantial impacts to those discussed for the project under any of 

the alternatives.

Determination Statement

Alternatives 1, 2, 3, 4 and 5 of the Tahoe National Forest Over-snow Vehicle Use Designation 

Project may affect individuals, but are not likely to lead to a loss of viability or a trend toward 

Federal listing for the great gray owl in the Forest Plan area for the following reasons: 

• Structure or composition of great gray owl habitat would not be physically modified by OSV use 

and related activities. 

• Although the potential for noise-based disturbance to individuals within high-reproductive 

habitat is 3 percent under all of the alternatives, great gray owl nesting has not been confirmed 

on the Tahoe National Forest. In the event that great gray owls nesting is found on the forest, the 
Over-snow Vehicle Use Designation

Tahoe National Forest

242

OSV-related noise-based disturbance would overlap with only the early part of the March 1 

through August 15 great gray owl breeding season, and nest sites with potential to be impacted 

would be monitored to determine whether disturbance is occurring and if changes in 

management, including a limited operating period around nest sites, are necessary, thereby 

minimizing impacts to the great gray owl.

• Due to their nocturnal behavior, great gray owls, if present, would be expected to have little 

interaction with snowmobiles or snow grooming equipment, resulting in minimal direct effects 

from snowmobiles or grooming equipment.

Willow Flycatcher (Empidonax trailii)

Species Account

This neotropical migrant species breeds within the contiguous United States, except the Southeast, 

and the southern margins of Canada (Green et al. 2003) and winters from Mexico to northern South 

America (USDA Forest Service 2001). 

Historically, this species likely occurred in suitable habitats throughout California and portions of 

Nevada including the central coast, Central Valley, Sierra Nevada, and Great Basin (summarized in 

USDA Forest Service 2001). Willow flycatchers were common in the Sierra Nevada until as recently 

as 1910, and locally abundant through 1940 (Ibid). However, this species has declined precipitously 

in the Sierra Nevada since 1950 (summarized in Green et al. 2003). Urbanization and the draining, 

channelization, and filling of wetlands; grazing; mining; and pesticide use are likely responsible for 

the decline in range and abundance of this species. Nest predation is the leading cause of nest failure 

in willow flycatcher nests (Mathewson et al. 2011). Human activity (presence of people, dogs, and 

vehicles) has also been found to be a significant impact to land birds, surpassing that of habitat loss 

from development (Schlesinger et al. 2008).

Willow flycatchers currently occur and breed on the Tahoe NF, primarily in the upper Truckee River

watershed where some of the largest montane meadow complexes occur, such as Perazzo Meadows.. 

The recent extirpation of this species from Yosemite National Park, where suitable habitats are 

presumably better preserved than those located outside the park suggests that other factors may be 

contributing to the decline of this species in the Sierra Nevada (Siegel et al. 2008). Siegel et al. (Ibid) 

tentatively suggested that severe habitat degradation during the 19th century (due to grazing, which 

was discontinued in Yosemite National Park decades ago), meadow desiccation (due to global 

warming and resulting in earlier spring melts and a reduction in site wetness), disrupted metapopulation dynamics, or conditions on the wintering grounds or along migration routes may explain 

the decline in Yosemite National Park.

Habitat Status

Suitable habitat (i.e., the combination of resources and environmental conditions required to survive 

and reproduce) for this species in the Sierra Nevada is defined by site elevation, shrub coverage, 

foliar density, wetness, and meadow size (summarized in Green et al. 2003). Known willow 

flycatcher sites range in elevation from 1,200 to 9,500 feet, though most (88 percent, 119 of 135) are 

located between 4,000 and 8,000 feet (Stefani et al. 2001). Willow flycatchers are closely associated 

with meadows that have high water tables in the late spring and early summer, and abundant 

shrubby, deciduous vegetation (especially Salix spp.). 

This species typically nests from June 1 to August 31 and fledges young between July 15 and 

August 31. Fledglings remain in territories for 2 for 3 weeks after fledging (USDA Forest Service 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

243

2004). However, these dates vary due to factors such as when willow flycatchers arrive on the 

breeding grounds, snowpack, late spring and summer weather, nest predation, and brown-headed 

cowbird parasitism (Green et al. 2003).

This species may attempt nesting as many as three times during a single breeding season in the Sierra 

Nevada (USDA Forest Service 2004). Nest predation has been positively associated with edge 

effects, distance of the nest to edges and isolated trees, and aspects of meadow size and wetness 

(Cain and Morrison 2003). 

Direct and Indirect Effects

There would be no direct effects to willow flycatchers from OSV use, since willow flycatchers arrive 

on their breeding grounds within the project area in mid to late May. The minimum cross-country 

snow depth varies between 12 to 24 inches under all the action alternatives and is expected to be 

adequate to protect vegetation from measurable impacts (McNamara 2017). Alternatives 3 and 5 

have the highest minimum snow depth and would likely protect willow flycatcher habitats the most 

compared to alternatives 1, 2 and 4. 

Cumulative Effects

The Tahoe National Forest Over-snow Vehicle Use Designation Project would not result in 

measurable direct or indirect impacts to the willow flycatcher and, therefore, there would be no 

cumulative impacts to this species.

Determination Statement

None of the alternatives of the Tahoe National Forest Over-snow Vehicle Use Designation Project 

would impact the willow flycatcher or its habitat for the following reasons:

• Willow flycatcher is a neotropical migrant that arrives well past the end of the OSV season of 

use, so no direct impacts to the species would occur.

• OSV use has not been identified as a factor in meadow degradation for this species, and the 

minimum cross-country snow depth of 12 inches under all of the action alternatives is expected 

to protect meadow and riparian habitats from measurable impacts to water quality or vegetation.

However, the potential for snow compaction in willow flycatcher meadows is moderate to high 

particularly in larger meadows adjacent to OSV routes, with alternatives 3 and 5 providing the 

most protection.

Greater Sandhill Crane (Grus Canadensis tabida)

Species Account

Greater sandhill cranes have been documented on the Tahoe National Forest. Sandhill cranes are 

known to breed on the Sierraville Ranger District at Kyburz Meadow and Perazzo Meadow, and on 

private land at Sardine Valley.

Habitat Status

The California breeding population of sandhill cranes winters chiefly in the Central Valley and peak 

breeding occurs between May and July. High reproductive habitats for sandhill crane include fresh 

emergent wetland, irrigated hayfield, and wet meadow (CWHR, CDFW 2013). 
Over-snow Vehicle Use Designation

Tahoe National Forest

244

Much of the acres classified as wetlands on Tahoe National Forest, which are important to waterfowl 

and sandhill crane, are seasonal; breeding occurs in spring and early summer. Threats to greater

sandhill crane include destruction and degradation of structurally diverse wet meadow and shallow 

emergent wetland habitats used for nesting and rearing habitat by conversions for road development, 

croplands, water diversions; predation; human disturbance of crane pairs during the nesting season; 

and the spread of invasive plants into greater sandhill crane habitats (USFWS 2015). 

Direct and Indirect Effects

Emissions from OSVs, particularly two-stroke engines on snowmobiles, release pollutants like 

ammonium, sulfate, benzene, PAHs and other toxic compounds that are stored in the snowpack; 

during spring snowmelt runoff, these accumulated pollutants are released and may be delivered to 

surrounding waterbodies (USDA National Forest Service National Core BMP Rec-7: Over-Snow 

Vehicle Use; refer to the project hydrology report for additional information). However, the 

minimum cross-country snow depth varies between 12 to 24 inches under all the action alternatives

is expected to be adequate to protect aquatic and riparian habitats from measurable impacts to 

vegetation or water quality (McNamara 2017).

Cumulative Effects

The Tahoe National Forest Over-snow Vehicle Use Designation Project would not result in 

measurable direct or indirect impacts to greater sandhill crane and, therefore, there would be no 

cumulative impacts to this species.

Determination Statement

None of the alternatives of the Tahoe National Forest Over-snow Vehicle Use Designation Project 

would impact the greater sandhill crane or its habitat for the following reasons:

• Greater sandhill crane is a migratory species that breeds outside of the OSV season of use, so no 

direct impacts to the species would occur.

• OSV use has not been identified as a factor in meadow degradation for this species, even though 

the minimum cross-country snow depth varies between 12 to 24 inches under all the action 

alternatives and is expected to be adequate to protect wet meadow and fresh emergent wetland 

habitats utilized by this species from measurable impacts to vegetation or water quality.

Terrestrial Invertebrates

Western Bumble Bee (Bombus occidentalis)

Species Account

Historically, the western bumble bee was one of the most broadly distributed bumble bee species in 

North America (Cameron et al. 2011). The species was broadly distributed across western North 

America along the Pacific Coast and westward from Alaska to the Colorado Rocky Mountains 

(Thorp and Shepard 2005, Koch et al. 2012). Currently, the western bumble bee occurs in all states 

adjacent to California, but is experiencing severe declines in distribution and abundance due to a 

variety of factors including diseases and loss of genetic diversity (Tommasi et al. 2004, Cameron et 

al. 2011, Koch et al. 2012). 

The overall status of populations in the West largely depends on geographic region: populations west 

of the Cascade and Sierra Nevada mountains are experiencing dire circumstances with steeply 

declining numbers, while those to the east of this dividing line are more secure with relatively 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

245

unchanged population sizes. The reasons for these differences are not known. The western bumble 

bee (Bombus occidentalis) has 94 collection records on 11 national forests in Region 5 (Hatfield 

2012) including the Tahoe National Forest.

Habitat Status

Bumble bees are threatened by many kinds of habitat alterations that may fragment or reduce the 

availability of flowers that produce the nectar and pollen they require and decrease the number of 

abandoned rodent burrows that provide nest and hibernation sites for queens. Major threats that alter 

landscapes and habitat required by bumble bees include agricultural and urban development. 

Exposure to insecticides has recently been identified as a major contributor to the decline of many 

pollinating bees, including honey bees and bumble bees (Hopwood et al. 2012). In the absence of 

fire, native conifers encroach upon meadows and this can also decrease foraging and nesting habitat 

available for bumble bees. 

Queens overwinter in the ground in abandoned rodent (i.e., mouse, chipmunk or vole) burrows at 

depths from 6 to 18 inches. In the late winter or early spring, the queen emerges from hibernation 

and then selects a nest site, which is often a pre-existing hole, such as an abandoned rodent hole.

Bumble bees require habitats with rich supplies of floral resources with continuous blooming from 

spring to autumn. Isolated patches of habitat are not sufficient to fully support bumble bee 

populations. Bumblebee colonies are annual.

Direct and Indirect Effects

Habitat loss and fragmentation may be playing a role in the decline of these bumble bee species. 

Habitat alterations that destroy, fragment, degrade, or reduce their food supplies, nest sites (e.g.,

abandoned rodent burrows or undisturbed grass), and hibernation sites for overwintering queens can 

harm these species (Evans et al. 2008). The minimum cross-country snow depth varies between 12 to 

24 inches under all the action alternatives and is expected to be adequate to protect vegetation from 

measurable impacts (McNamara 2017).

Cumulative Effects

The Tahoe National Forest Over-snow Vehicle Use Designation Project would not result in 

measurable direct or indirect impacts to the western bumble bee and, therefore, there would be no 

cumulative impacts to this species.

Determination Statement

None of the alternatives of the Tahoe National Forest Over-snow Vehicle Use Designation Project 

would impact the western bumble bee or its habitat based on the following rationale:

• Colonies are annual outside of the OSV season.

• Queens of the species hibernate during the OSV season of use and, therefore, proposed actions 

would not result in noise impacts or impacts to foraging or breeding.

• Known information suggests that bumble bee queens burrow under duff under trees and on 

steeper slopes where OSV use does not occur (refer to OSV use assumptions).

• OSV use is not expected to degrade terrestrial habitat based upon a minimum cross-country 

snow depth which varies between 12 to 24 inches to be maintained under all the action 

alternatives.
Over-snow Vehicle Use Designation

Tahoe National Forest

246

Terrestrial Wildlife Species of Public Interest

Table 82. Additional terrestrial species of interest identified during public scoping

Species Name TEPCS 

Status

Project Area 

Within Species’ 

Range

Detections 

in or Near 

the Project 

Area

Suitable 

Habitat 

Present

Species Addressed 

Further/Rationale

Mule deer 

(Odocoileus 

hemionus)

MIS Yes Yes Yes Yes/Addressed with 

respect to impacts 

associated with winter 

range.

Subnivean species: 

Shrews (Sorex spp.), 

Voles (Microtus spp.), 

and Deer mouse 

(Peromyscus 

maniculatus)

None Yes Yes Yes Yes

Mule Deer

Management indicator species for oak-associated hardwood and hardwood conifer in the Sierra 

Nevada bioregion. 

Potential effects to mule deer on their winter range was identified as a non-significant issue during 

public scoping. Please refer to the Management Indicator Species section for mule deer population 

status and trend, habitat status and trend, and project-level habitat impacts.

Table 83. Resource indicators and measures for assessing effects to mule deer on winter range

Resource Indicator and 

Effect

Measure

(Quantify if 

possible)

Alternative 

1

Alternative 

2

Alternative 

3

Alternative 

4

Alternative 

5

Potential for disturbance to 

individuals from OSV use 

and increased human 

presence, injury or mortality 

of individuals, or habitat 

modification (i.e., altered 

movement due to OSV use)

Acres of 

winter 

range 

affected by 

OSV use

2,915 2,915 2,915 3,975 2,337

Species Account

Mule deer range and habitat include coniferous forest, foothill woodland, shrubland, grassland, 

agricultural fields, and suburban environments (CDFW 2014). Many mule deer migrate seasonally 

between higher elevation summer range and low-elevation winter range (Ibid). On the west slope of 

the Sierra Nevada, oak-associated hardwood and hardwood/conifer areas are an important winter 

habitat (CDFW 1998). 

Mule Deer Habitat Status

Tahoe National Forest contains 194,973 acres of mule deer winter range, with 32,674 (16 percent) 

acres conducive to OSV use.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

247

Direct and Indirect Effects

Wintering deer are sensitive to disturbances of all kinds. Both snowmobiles and cross-country skiers 

are known to cause wintering ungulates to flee (Freddy et al. 1986). Dorrance et al. (1975) found that 

snowmobile traffic resulted in increased home range size, increased movement, and displacement of 

deer from areas along trails. Direct environmental impacts of snowmobiles include collisions causing 

mortality and harassment that increased metabolic rates and stress responses (Gaines et al 2003). 

Based upon Freddy et al. (1986), the distance at which mule deer have been shown to be displaced 

by OSVs is 133 meters (436 feet). 

Snowmobile use within mule deer winter range can have the following direct effects on individual 

mule deer or their habitat (Gaines et al. 2003): (1) displacement of populations or individual animals 

from a route, related to human activities; (2) disturbance and displacement of individuals from 

breeding or rearing habitats; (3) physiological response to disturbance, resulting in changes in heart 

rate or level of stress hormones; and (4) potential for injury or mortality to individuals from vehicle 

collision. Possible indirect effects include altered or dispersed movement as caused by a route or 

human activities on or near a route. 

Table 84 displays the amount of deer winter range, by alternative, with the potential for direct 

(disturbance and vehicle collision) and indirect (habitat modification) effects as described above. As 

previously discussed, the likelihood of a collision between snow grooming equipment and wildlife is 

extremely low because the equipment travels slowly (3 to 6 mph). There is an increased likelihood of 

collision with OSVs due to higher frequency of OSV use and higher speeds. Vehicle collision with a 

mule deer would negatively affect the individual, but the likelihood of occurrence is assumed to be 

rare.

Table 84. Acres of mule deer winter range with potential to be impacted by OSV use and related 

activities

Alternative 1 Alternative 

2

Alternative 3 Alternative 

4

Alternative 

5

Designated for OSV use 64,808 12,884 74,089 69,324 64,808

Total 194,973 194,973 194,973 194,973 194,973

Designated and conducive to 

OSV use

32,658 8,226 2,915 3,975 2,337

OSV use of existing linear routes and cross-country travel is allowed within winter range, at some 

level, under all alternatives. Under the current condition (alternative 1), 130,165 acres (66 percent) of 

mule deer winter range is not designated for OSV use. Therefore, deer using that portion of winter 

range would not be impacted by authorized OSV use. Roughly 34 percent of winter range is 

designated for OSV use. However, only 32,658 acres or 50 percent of winter range are designated

and conducive to OSV use (slopes less than 20 percent and canopy cover less than 70 percent).

Subnivean Species 

Subnivean habitats are important for small mammal species and may be indirectly affected by OSV 

use through snow compaction. For the alternatives, minimum snow depths was used to analyze the 

potential for snow compaction on subnivean habitat.
Over-snow Vehicle Use Designation

Tahoe National Forest

248

Table 85. Resource indicators and measures for assessing effects to subnivean species

Resource 

Indicator and 

Effect

Measure

(Quantify if 

possible)

Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Potential for 

effects of 

snow 

compaction 

on subnivean 

species 

habitat

Acres and 

percentage of 

habitat

impacted by 

OSV use 

[addressed 

under each 

applicable

predator 

species 

(marten, 

CSO)]

With no 

minimum 

snow depth, 

damage to 

subnivean 

habitat could 

occur where 

snow levels 

are not 

sufficient to 

protect 

subnivean 

habitat.

Snow 

compaction on 

subnivean 

habitat is 

unlikely to 

occur when 

snow depth is 

at least 12 

inches.

Snow 

compaction on 

subnivean 

habitat is least 

likely to occur 

when snow 

depth is least 

18 inches. 

Snow 

compaction on 

subnivean 

habitats is 

unlikely to 

occur when 

snow depth is 

at least 12 

inches

Snow 

compaction 

on subnivean 

habitat is 

least likely to 

occur when 

snow depth is 

at least 24 

inches.

Species Account

Subnivean species [shrews (Sorex spp.), voles (Microtus spp.), and deer mouse Peromyscus 

maniculatus)] do not warrant special status at this time because populations are assumed to be 

secure. However, Gaines et al. (2003) found an interaction that occurred on winter recreation routes 

was the indirect effect of snow compaction on the subnivean sites used by small mammals in which 

small mammals can either be suffocated as a result of the compaction, or their subnivean movements 

can be altered owing to impenetrable compact snow.

Habitat Status

Adaptations to snowpack are an important component of the ecology of small mammals in temperate 

climates. Some small mammals, such as chipmunks (Tamias spp), hibernate and have limited 

interaction with the snowpack environment. However, shrews and voles stay active throughout the 

winter, and much of their activity occurs in the subnivean space under the snowpack. Other species 

(deer mouse) undergo bouts of torpor between periods of activity. Subnivean mammals are 

dependent on the subnivean space between the basal layer of snow and the ground for shelter, 

foraging and travel.

Subnivean space may be formed in one of two ways: mechanically or thermally, and varies by region 

and type of snow. Subnivean space forms mechanically when the weight of the snowpack is 

supported by vegetation, woody debris, or complex rocky environments. Extensive subnivean space 

may be formed thermally in environments with a temperature gradient between the bottom and top of 

the snowpack. As water vapor migrates up from warmer to colder regions of the snow, depth hoar 

forms just above the ground at the base of the snowpack. Depth hoar is brittle, loosely arranged 

crystals that create space in the subnivean environment and facilitate travel by small mammals that 

readily move through the fragile crystals. Depth hoar commonly forms and is most well-developed in 

cold, continental-type regions where temperature throughout the snowpack varies significantly. 

Depth hoar is rare to nonexistent in snow classified as maritime, such as that in the Sierra Nevada, 

which also tends to be more isothermal.

Studies cited as the basis for impacts to the subnivean environment and subnivean animals have 

generally been conducted in locations with continental snowpacks (e.g., alpine) where depth hoar 

develops (Wildlife Resource Consultants 2004). A lack of studies investigating the distribution of 

subnivean space and the effects of winter recreation on subnivean space in maritime snowpack 

conditions, such as those found in the Sierra Nevada Mountains, resulted in the Forest Service 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

249

commissioning a study (Wildlife Resource Consultants 2004) designed to examine the distribution of 

subnivean space in Sierra meadows, how it is formed, and the impacts of winter recreation on 

snowpack characteristics and subnivean space. Key findings from the 65 snow pits examined for 

subnivean space, density characteristics, temperature, vegetation type, and the presence of small 

mammal sign included the following:

• The subnivean space did not contain depth hoar.

• Vegetation community types should be considered in managing winter recreation use in the 

Sierra Nevada; wet meadows at low elevations (1,917 to 1,933 meters; 6,289 to 6,342 feet in 

study) with low snow depth probably have the most subnivean space. 

• Findings were not as conclusive regarding the effects of recreational use on subnivean space. But 

there is some suggestion that winter recreation may impact subnivean space at low elevations 

[pooled data for all sites were analyzed by recreational use category; pits classified as 

concentrated over-snow vehicle use had the least subnivean space, an average of 6.0 percent

(n=7)].Winter recreation probably has the greatest effect at low snow depths (0 to

64 centimeters; 0 to 25 inches).

The habitat of species active in the winter includes mesic and dry meadows throughout the Sierra 

Nevada. With the exception of trails, meadows are where some of the highest OSV use occurs and, 

therefore, riskfor effects to subnivean species is greatest.

Direct and Indirect Effects

Gaines et al. (2003) found an interaction that occurred on winter recreation routes was the indirect 

effect of snow compaction on the subnivean sites used by small mammals, in which small mammals 

can either be suffocated as a result of the compaction, or their subnivean movements can be altered 

because of the impenetrable compact snow. As reflected in public comments during scoping, any 

adverse effects to subnivean animals could indirectly affect the prey base for many Forest Service 

sensitive species, including California spotted owl, northern goshawk, and marten.

Alternative 1 provides the least protection for subnivean species, where damage to subnivean 

resources could occur, since no minimum snow depth is required under existing Forest Plan 

direction. Under alternative 2, adequate snow cover (generally about 12 inches) is required to 

prevent resource damage, and would potentially protect subnivean resources. Similarly, alternative 4 

would likey protect subnivean habitat with a minimum snow depth of 12 inches. Alternatives 3 and 

5 provide the greatest protection of subnivean habitat with at least 18 and 24 inches snow depth, 

respectively.

Management Indicator Wildlife Species

The purpose of this analysis is to evaluate and disclose the impacts of the Tahoe National Forest 

Over-snow Vehicle Designation Project on the habitat of the 13 management indicator species (MIS) 

identified in the Land and Resource Management Plan (USDA Forest Service 1992) as amended by 

the Sierra Nevada Forests Management Indicator Species Amendment Record of Decision (USDA 

Forest Service 2007a).
Over-snow Vehicle Use Designation

Tahoe National Forest

250

Direction Regarding the Analysis of Project-level Effects on MIS 

Habitat

MIS are animal species identified in the SNF MIS Amendment Record of Decision (ROD) signed 

December 14, 2007, which was developed under the 1982 National Forest System Land and 

Resource Management Planning Rule (1982 Planning Rule) (36 CFR 219). Guidance regarding MIS 

set forth in the 1990 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 1990 LRMP as amended.

Adequately analyzing project effects to MIS generally involves the following steps:

• Identifying which habitat and associated MIS would be either directly or indirectly affected 

by the project alternatives; these MIS could be affected by the project.

• Summarizing the bioregional-level monitoring identified in the LRMP, as amended, for this 

subset of MIS.

• Analyzing project-level effects on MIS habitat for this subset of MIS.

• Discussing bioregional scale habitat and/or population trends for this subset of MIS. 

• Relating project-level impacts on MIS habitat to habitat and/or population trends at the 

bioregional scale for this subset of MIS.

These steps are described in detail in the Pacific Southwest Region’s draft document MIS Analysis 

and Documentation in Project-Level NEPA, R5 Environmental Coordination (May 25, 2006) (USDA 

Forest Service 2006a). This MIS Report documents application of the above steps to select projectlevel MIS and analyze project effects on MIS habitat for the Tahoe OSV Use Designation.

Direction Regarding Monitoring of MIS Population and Habitat Trends 

at the Bioregional Scale 

The bioregional scale monitoring strategy for the Tahoe National Forest’s MIS is found in the Sierra 

Nevada Forests Management Indicator Species Amendment Record of Decision (ROD) of 2007 

(USDA Forest Service 2007a). Bioregional scale habitat monitoring is identified for 12 of the 

terrestrial MIS. In addition, bioregional scale population monitoring, in the form of distribution 

population monitoring, is identified for all of the terrestrial MIS except for the greater sage-grouse. 

For aquatic macroinvertebrates, the bioregional scale monitoring identified is Index of Biological 

Integrity and Habitat. The current bioregional status and trend of populations and/or habitat for each 

of the MIS is discussed in the 2010 Sierra Nevada Forests Bioregional Management Indicator 

Species Report (USDA Forest Service 2010a).

MIS Habitat Status and Trend

All habitat monitoring data are collected and/or compiled at the bioregional scale, consistent with the 

LRMP as amended by the 2007 SNF MIS Amendment ROD (USDA Forest Service 2007a).

Habitats are the vegetation types (for example, early seral coniferous forest) or ecosystem 

components (for example, snags in green forest) required by an MIS for breeding, cover, and/or 

feeding. MIS for the Sierra Nevada National Forests represent 10 major habitats and 2 ecosystem 

components (USDA Forest Service 2007a), as listed in table 86. These habitats are defined using the 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

251

CWHR System (CDFG 2005). The CWHR System provides the most widely used habitat 

relationship models for California’s terrestrial vertebrate species (ibid). It is described in detail in the 

2010 SNF Bioregional MIS Report (USDA Forest Service 2010a).

Habitat status is the current amount of habitat on the Sierra Nevada Forests. Habitat trend is the 

direction of change in the amount or quality of habitat over time. The methodology for assessing 

habitat status and trend is described in detail in the 2010 SNF Bioregional MIS Report (USDA Forest 

Service 2010a).

Aquatic Macroinvertebrate Status and Trend

For aquatic macroinvertebrates, condition and trend is determined by analyzing macroinvertebrate 

data using the predictive, multivariate River Invertebrate Prediction and Classification System 

(RIVPACS) (Hawkins 2003) to determine whether the macroinvertebrate community has been 

impaired relative to reference condition within perennial waterbodies. This monitoring consists of 

collecting aquatic macroinvertebrates and measuring stream habitat features according to the Stream 

Condition Inventory manual (Frasier et al. 2005). Evaluation of the condition of the biological 

community is based upon the “observed to expected” (O/E) ratio, which is a reflection of the number 

of species observed at a site versus the number expected to occur there in the absence of impairment. 

Sites with a low O/E scores have lost many species predicted to occur there, which is an indication 

that the site has a lower than expected richness of sensitive species and is therefore impaired. 

Selection of Project-level MIS

Management Indicator Species (MIS) for the Tahoe National Forest are identified in the 2007 Sierra 

Nevada Forests Management Indicator Species (SNF MIS) Amendment (USDA Forest Service 

2007a). The habitats and ecosystem components and associated MIS analyzed for the project were 

selected from this list of MIS, as indicated in table 86. In addition to identifying the habitat or 

ecosystem components (1st column), the CWHR type(s) defining each habitat/ecosystem component 

(2nd column), and the associated MIS (3rd column), the table discloses whether or not the habitat of 

the MIS is potentially affected by the Tahoe OSV Use Designation (4th column).

Table 86. Selection of MIS for Project-Level Habitat Analysis for the Tahoe OSV Use Designation

Habitat or Ecosystem 

Component

CWHR Type(s) defining the 

habitat or ecosystem 

component1

Sierra Nevada Forests

Management Indicator 

Species

Scientific Name

Category 

for Project 

Analysis2

Riverine & Lacustrine lacustrine (LAC) and riverine (RIV) aquatic 

macroinvertebrates

2

Shrubland (west-slope 

chaparral types)

montane chaparral (MCP), mixed 

chaparral (MCH), chamiseredshank chaparral (CRC)

fox sparrow

Passerella iliaca

2

Sagebrush Sagebrush (SGB) greater sage-grouse

Centrocercus 

urophasianus

2

Oak-associated Hardwood & 

Hardwood/conifer

montane hardwood (MHW), 

montane hardwood-conifer (MHC)

mule deer

Odocoileus hemionus

2

Riparian montane riparian (MRI), valley 

foothill riparian (VRI)

yellow warbler

Dendroica petechia

2

Wet Meadow Wet meadow (WTM), freshwater 

emergent wetland (FEW)

Pacific tree (chorus) frog

Pseudacris regilla

2
Over-snow Vehicle Use Designation

Tahoe National Forest

252

Habitat or Ecosystem 

Component

CWHR Type(s) defining the 

habitat or ecosystem 

component1

Sierra Nevada Forests

Management Indicator 

Species

Scientific Name

Category 

for Project 

Analysis2

Early Seral Coniferous Forest ponderosa pine (PPN), Sierran 

mixed conifer (SMC), white fir 

(WFR), red fir (RFR), eastside pine 

(EPN), tree sizes 1, 2, and 3, all 

canopy closures

Mountain quail

Oreortyx pictus

2

Mid Seral Coniferous Forest ponderosa pine (PPN), Sierran 

mixed conifer (SMC), white fir 

(WFR), red fir (RFR), eastside pine 

(EPN), tree size 4, all canopy 

closures

Mountain quail

Oreortyx pictus

2

Late Seral Open Canopy 

Coniferous Forest

ponderosa pine (PPN), Sierran 

mixed conifer (SMC), white fir 

(WFR), red fir (RFR), eastside pine 

(EPN), tree size 5, canopy 

closures S and P

Sooty (blue) grouse

Dendragapus obscurus

2

Late Seral Closed Canopy 

Coniferous Forest

ponderosa pine (PPN), Sierran 

mixed conifer (SMC), white fir 

(WFR), red fir (RFR), tree size 5 

(canopy closures M and D), and 

tree size 6.

California spotted owl

Strix occidentalis 

occidentalis

2

American marten

Martes americana

northern flying squirrel

Glaucomys sabrinus

Snags in Green Forest Medium and large snags in green 

forest

hairy woodpecker

Picoides villosus

2

Snags in Burned Forest Medium and large snags in burned 

forest (stand-replacing fire)

black-backed 

woodpecker

Picoides arcticus

2

1 All CWHR size classes and canopy closures are included unless otherwise specified; dbh = diameter at breast height; 

Canopy Closure classifications: S=Sparse Cover (10-24% canopy closure); P= Open cover (25-39% canopy closure); M= 

Moderate cover (40-59% canopy closure); D= Dense cover (60-100% canopy closure); Tree size classes: 1 (Seedling)(<1" 

dbh); 2 (Sapling)(1"-5.9" dbh); 3 (Pole)(6"-10.9" dbh); 4 (Small tree)(11"-23.9" dbh); 5 (Medium/Large tree)(>24" dbh); 6 (Multilayered Tree) [In PPN and SMC] (Mayer and Laudenslayer 1988).

2 Category 1: MIS whose habitat is not in or adjacent to the project area and would not be affected by the project.

Category 2: MIS whose habitat is in or adjacent to project area, but would not be either directly or indirectly affected by the 

project.

Category 3: MIS whose habitat would be either directly or indirectly affected by the project.

Migratory Landbirds

Under the National Forest Management Act, the Forest Service is directed to “provide for diversity 

of plant and animal communities based on the suitability and capability of the specific land area in 

order to meet overall multiple-use objectives.” (P.L. 94-588, Sec 6 (g) (3) (B)). The January 2000 

USDA Forest Service (FS) Landbird Conservation Strategic Plan, followed by Executive Order 

13186 in 2001 and the January 2004 Partners in Flight North American Landbird Conservation Plan 

all reference goals and objectives for integrating bird conservation into forest management and 

planning.

In late 2008, a Memorandum of Understanding between the USDA Forest Service and the U.S. Fish 

and Wildlife Service to Promote the Conservation of Migratory Birds was signed. The intent of the 

MOU is to strengthen migratory bird conservation through enhanced collaboration and cooperation 

between the Forest Service and the Fish and Wildlife Service as well as other Federal, State, Tribal 

and local governments. 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.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

253

Likely impacts to habitats the migratory birds depend on have been assessed in further detail within 

the Biological Assessment, Biological Evaluation and the Management Indicator Species reports for 

the Tahoe National Forest Over-snow Vehicle Designation Project. All reports found that effects to 

various habitats would be minimal to none considering that forested cover is not modified. Similarly, 

OSV use is concentrated between December 26 through and March 31, which predominately avoids 

overlap with the active breeding season for most migratory bird species. These reports found that the

Tahoe National Forest Over-snow Vehicle Designation Project would not cause adverse effects 

(Biological Assessment), would not cause a trend toward a loss of viability (Biological Evaluation), 

nor would it degrade various MIS habitats to a level that affects trends in the Sierra Nevada 

bioregion. Also, possible impacts to migratory species are minimized through the adherence of 

LRMP standards and guidelines for snags and down woody debris, avoidance of streamside 

management zones, and no degradation in riparian areas and wetlands. 

Therefore, the Tahoe National Forest Over-snow Vehicle Designation Project would have minimal 

impacts to individual migratory birds and would not adversely affect migratory landbird 

conservation. This finding is based on the results of analysis conducted in the Biological 

Assessment, Biological Evaluation, and Management Indicator Species reports, and that adherence 

to LRMP standards are adhered to, which in turn would maintain habitat diversity. The project meets 

the intent of the Migratory Landbird MOU.

Aquatics

Relevant Laws, Regulations, and Policy

Regulatory Framework

Land and Resource Management Plan

The Tahoe National Forest LRMP provides direction specific to management of fish, water and 

riparian areas, and is found as goals, objectives, and standards and guidelines in chapter 4 of the 

LRMP as well as in the Northwest Forest Plan and SNFPA, both of which include aquatic 

conservation strategies (including a long-term strategy in the SNFPA for management of anadromous 

fishes on the Tahoe National Forest. Aquatic Conservation Strategies are found in their entirety in 

each of the aforementioned amendments to the LRMP.

Endangered Species Act

The Endangered Species Act of 1973 (16 U.S.C. 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 critical habitat for these species. 

Section 7 of the Endangered Species Act, as amended, requires the responsible Federal agency to 

consult the USFWS and the National Marine Fisheries Service concerning threatened or endangered 

species under their jurisdiction. It is Forest Service policy to analyze impacts to threatened or 

endangered species species to ensure management activities are not likely to jeopardize the 

continued existence of a threatened or endangered species, or result in the destruction or adverse 

modification of critical habitat for these species. This assessment is documented in a biological 

assessment.

Forest Service Manual and Handbooks (FSM/H 2670)

Forest Service sensitive species are species identified by the Regional Forester for which population 

viability is a concern. The Forest Service develops and implements management practices to ensure 
Over-snow Vehicle Use Designation

Tahoe National Forest

254

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.

Forest Service Manual 2670.32 (USDA Forest Service 2005)

The manual directs the forest to avoid or minimize impacts to species whose viability has been 

identified as a concern, and therefore, listed as sensitive by the Regional Forester. If impacts cannot 

be avoided, then the forest must analyze the significance of the potential adverse effects on the 

population or its habitat within the area of concern and on the species as a whole. Impacts may be 

allowed, but the decision must not result in a trend toward Federal listing. 

Forest Service Manual 2670.22 (USDA Forest Service 2005)

The manual directs national forests to “maintain viable populations of all native and desired 

nonnative wildlife, fish, and plant species in habitats distributed throughout their geographic range 

on National Forest System lands.” To comply with this direction, forests are encouraged to track and 

evaluate effects to additional species that may be of concern even though they are not currently listed 

as sensitive. Such plant species are referred to as species of interest or watch list species.

Sierra Nevada Forest Plan Amendment 

The Sierra Nevada Forest Plan Amendment (2004b) amended each of the forest plans in the Sierra 

Nevada and provides regional direction to restore aquatic, riparian, and meadow ecosystems and 

provide for the viability of native plant and animal species associated with these ecosystems. This 

includes mountain yellow-legged frogs, Yosemite toads, and their habitats. This regional direction is 

represented by an array of features that, in their entirety, constitute an aquatic management strategy 

for the Sierra Nevada. The fundamental principle of the aquatic management strategy is to retain, 

restore, and protect the processes and landforms that provide habitat for aquatic and ripariandependent organisms. Accomplishment of these objectives are achieved through a combination of 

tactics such as standards and guidelines and policies that are intended to work collectively, and 

include a suite of interrelated actions that work together to manage and conserve aquatic habitats. 

Riparian Conservation Areas: Activity-related Standards and Guidelines

Where a proposed project encompasses a riparian conservation area or a critical aquatic refuge, 

conduct a site-specific project area analysis to determine the appropriate level of management. 

Determine the type and level of allowable management activities by assessing how proposed 

activities measure against the riparian conservation objectives and their associated standards and 

guidelines. Areas included in riparian conservation areas are: 300 feet on each side of perennial 

streams; 150 feet on each side of intermittent and ephemeral streams; and 300 feet from lakes, 

meadow, bogs, fens, wetlands, vernal pools, and springs.

Resource Indicators and Measures 

Resource indicators and measures shown in table 19 will be used to measure and disclose effects to 

aquatic wildlife related to OSV use designations and grooming trails for OSV use.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

255

Table 87. Aquatic indicators and measures for assessing effects 

Resource Element Resource Indicator Measure

Threatened and 

Endangered Species

Aquatic habitat Acres designated for cross-country OSV in critical 

and suitable habitat

Critical and suitable habitat (acres) within 100 feet 

of OSV trails

Methodology

This analysis uses relevant GIS data layers from the Tahoe National Forest. The GIS layers of 

proposed OSV designations and groomed trails were overlain with the aquatic resource (i.e., species 

distribution, critical habitat, surveys) layers to identify areas of potential effects.

One of four possible determinations is chosen based on the available literature, a thorough analysis 

of the potential effects of the project, and the professional judgment of the biologist who completed 

the evaluation. The four possible determinations (from FSM 2672.42) are:

1. “No impact” – where no impact is expected;

2. “Beneficial impact” – where impacts are expected to be beneficial;

3. “May affect individuals, but is not likely to result in a trend toward Federal listing or loss of 

viability in the planning area” – where impacts are expected to be immeasurable or 

extremely unlikely; and

4. “May affect individuals, and is likely to result in a trend toward Federal listing or loss of 

viability in the planning area” – where impacts are expected to be detrimental and 

substantial.

Similar categories for federally listed threatened and endangered species are:

1. No effect

2. Beneficial effect

3. May affect, not likely to adversely affect

4. May affect, likely to adversely affect

OSV Use Assumptions for Analysis

Assumptions used for the analysis are based on published literature and professional judgement 

based on experience by an aquatics specialist with the USDA Forest Service. These sources of 

information framed the issues key indicators used for analyzing the environmental consequences of 

each alternative on aquatic resources. They provide background information and conclusions 

regarding the effects of OSVs and other factors considered in this analysis, and apply to all 

alternatives.

• Aquatic species are unlikely to be directly affected by authorized OSV use (OSVs are not 

authorized to operate over bare ground or areas with inadequate snow depth that would 

cause resource damage as described in 36 CFR part 261.15).

• Indirect effects, such as those possibly resulting from snow compaction and vehicle 

emissions, are likely to be concentrated in the corridors along designated OSV trails 

(groomed or ungroomed) because OSV use is concentrated. Therefore, an area within 
Over-snow Vehicle Use Designation

Tahoe National Forest

256

100 feet of designated OSV trails has the greatest risk of being affected by snow 

compaction, emissions, or other contamination. Areas designated for OSV use outside these 

concentrated use corridors are much less likely to experience measurable indirect effects.

• Only authorized OSV uses will be analyzed. Concerns arising from unauthorized uses will 

be addressed as law enforcement issues and may prompt corrective actions. 

• Future aquatic resource-related monitoring may identify unexpected types or levels of 

impacts to aquatic resources, and may prompt corrective actions as warranted.

Spatial and Temporal Context for Effects Analysis

Direct and Indirect Effects Boundaries

The spatial boundary for analyzing the direct and indirect effects to aquatic resources is the project 

area boundary, because all expected effects relevant to this resource would occur and remain within 

this area.

Effects to aquatic species or their habitat would be expected to have occurred or become evident 

within one or two years of disturbance and this constitutes the short term. Effects that linger beyond 

two years are considered long-term effects. Long-term effects beyond two years become increasingly 

difficult to predict due to unknown interactions and the many environmental variables with 

numerous possible outcomes.

Cumulative Effects Boundaries

Because effects from the proposed activities would interact with effects from other ongoing or future 

projects only within the project area boundary, the cumulative effects boundary is also the project 

area boundary. The project area boundary is the national forest boundary for the Tahoe National 

Forest for the following reasons: the forest boundary is large enough to address wide-ranging species 

and Forest Service sensitive species’ viability is assessed at the Forest Plan area. The temporal 

boundary for this analysis is 10 years from the signing of the decision document and is based on 

adequate time for an assumed effectiveness monitoring program to be designed and implemented and 

for results to be assessed.

Affected Environment and Environmental Consequences for 

Endangered, Threatened, Sensitive or Proposed Species and/or their 

Designated Critical Habitat

Threatened, Endangered, and Proposed Aquatics Species

Official species lists for the Tahoe National Forest Over-snow Vehicle Use Designation Project were 

obtained on April 13, 2016, and August 21, 2016 from the Sacramento, and Nevada Field Offices of 

the U.S. Department of the Interior, Fish and Wildlife Service (USFWS 2016a, 2016b). An updated 

list was obtained on September 9, 2016, and in December of 2017, through the FWS Information for 

Planning and Conservation website (https://ecos.fws.gov/ipac/) from the Sacramento, and Nevada 

Fish and Wildlife Service office. The lists identify aquatic species to consider because they may be 

present within the general area of the Tahoe National Forest.

Table 88 identifies aquatic species to consider, because of their possible presence in the general area 

of the Tahoe National Forest. Species that are not known or suspected to occur in areas that are

designated for OSV use are not carried forward into the effects analysis.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

257

Table 88. Threatened, endangered, proposed, and sensitive (TEPS) aquatic species considered and 

designated or proposed critical habitat considered in this analysis

Species Status

Known or 

Potential 

Occurrence

Species Addressed 

Further/Rationale

Amphibians/Reptiles

1 California Red-legged Frog 

(Rana draytonii)

USFWS 

Threatened

Potential 

Occurrence

Yes, discussed further in this 

document

2 Western Pond Turtle

(Actinemys marmorata)

USFS Sensitive Known 

Occurrence

Yes, discussed further in this

document

3 Foothill Yellow-legged Frog 

(Rana boylii)

USFS Sensitive Known 

Occurrence

Yes, discussed further in this 

document

4 Sierra Nevada Yellow-legged 

Frog

(Rana sierrae)

USFWS 

Endangered 

Known 

Occurrence

Yes. Exist in only a few 

populations in ponds and streams 

and generally in small numbers on 

the forest.

Fishes

5 Lahontan Cutthroat Trout

(Oncorhynchus clarkii 

henshawi)

USFWS 

Threatened

Known 

Occurrence

Yes, discussed further in this 

document

6 Hardhead 

(Mylopharodon 

conocephalus)

USFS Sensitive Known 

Occurrence

Yes, discussed further in this 

document

7 Cui-ui

(Chasmistes cujus)

USFWS 

Endangered

No Potential 

Occurrence

No Effect. Species and habitat 

does not exist on Tahoe National 

Forest.

8 Lahontan Lake Tui Chub

(Siphatales bicolor pectinifer)

USFS Sensitive Potential 

Occurrence

Yes, discussed further in this 

document

9 Delta smelt 

(Hypomesus transpacificus)

USFWS 

Threatened

No Potential 

Occurrence

No Effect. Species and habitat 

does not exist on Tahoe National 

Forest.

10 Central Valley Steelhead 

(Oncorhynchus (=salmo) 

mykiss)

USFWS 

Threatened

No Potential 

Occurrence

No Effect. Species and habitat 

does not exist on Tahoe National 

Forest.

Aquatic Invertebrates

11 Great Basin Rams-horn snail 

(Helisoma newberryi)

USFS Sensitive Potential 

Occurrence

Yes, discussed further in this 

document

12 California Floater

(Anodonta californiensis)

USFS Sensitive Potential 

Occurrence

Yes, discussed further in this 

document

13 Black Juga 

(Juga nigra)

USFS Sensitive Potential 

Occurrence

Yes, present within stream located 

within project boundaries; 

considered in analysis.

CRITICAL HABITATS WITHIN THE PROJECT AREA

Species Status Occurrence Analysis

California Red-legged Frog 

(Rana draytonii)

Final 

Designated

Known 

Occurrence on 

private land 

adjacent to 

NFS land

Yes

Sierra Nevada Yellow-legged 

Frog

(Rana sierrae)

Final 

Designated

Known 

Occurrence

Yes
Over-snow Vehicle Use Designation

Tahoe National Forest

258

California Red-legged Frog (USFWS Threatened)

On June 24, 1996, the California red-legged frog, Rana draytonii, was listed as federally threatened 

(USFWS 1996). The final California Red-legged Frog Recovery Plan was released on September 12, 

2002 (USFWS 2002; 67 FR 57830). On March 17, 2010, the USFWS finalized designation of 

critical habitat within three locations in or adjacent to the Tahoe National Forest (USFWS 2010; 75 

FR 12816).

The western portion of the Tahoe National Forest falls within the Sierra Nevada recovery unit 

(recovery unit #1) (USFWS 2002). The Plumas and Tahoe National Forests share core area #2 Yuba 

River-South Fork Feather River located in Yuba County (USFWS 2002). This core area includes a 

portion of the North Yuba River around New Bullards Bar Reservoir. While the goal of the recovery 

plan is to protect the long-term viability of all existing populations within each recovery unit, 

recovery actions would be focused within, but not limited to, core areas (USFWS 2002).

In the Sierra Nevada, the California Red-legged Frog historically occupied portions of the lower 

elevations west of the crest from Shasta County south to Tulare County (USFWS 2002). Almost all 

known California Red-legged Frog populations have been documented at elevations below 1,050 

meters (3,500 feet) with some historical sightings documented at elevations up to 1,500 meters 

(5,200 feet) (USFWS 2002). The Tahoe National Forest’s definition of suitable California Redlegged Frog breeding habitat includes all ponds, lakes and reservoirs on the west slope of the forests 

that contain water through July in years with average precipitation, and low gradient stream reaches 

(less than 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. Habitats are of a higher quality if they are not 

occupied by non-native predators.

Due to habitat alteration, and exotic species, overall there is limited suitable habitat for California 

red-legged frog in the Tahoe National Forest. In 1997, Dr. Gary Fellers, USGS, Point Reyes, 

California, surveyed all known suitable California Red-legged Frog habitat on the forest. His 

conclusion on the suitability of Tahoe National Forest lands for California Red-legged Frog was, “I 

am pretty comfortable with saying that there are few or no populations remaining on Federal land 

that we visited. There remains a fair possibility that a few populations may exist on private lands, but 

those are largely inaccessible to us.”

The Tahoe National Forest currently has two Critical Aquatic Refuges: Upper Independence Creek 

and Sierra Buttes, neither of which includes known populations of California Red-legged Frog. 

Critical Aquatic Refuges are small subwatersheds that contain either (1) known locations of 

threatened, endangered or sensitive species; (2) highly vulnerable populations of native plant or 

animal species; or (3) localized populations of rare native aquatic- or riparian-dependent plant or 

animal species.

Tahoe National Forest biologists regularly note amphibians found in aquatic habitats and annually 

conduct stream surveys across portions of the forests. Suitable habitat such as marshes, ponds and 

low gradient streams occur on a number of sites within the historical range of this species in the 

Tahoe National Forest. Intensive surveys for California Red-legged Frogs have occurred on the 

Tahoe National Forest (1996 to present). Within suitable habitat, most of these surveys have 

followed the USFWS California Red-legged Frog survey protocol (1997, 2005). Since the release of 

the 2005 protocol, surveys that are conducted would follow the new 8-visit protocol. 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

259

Western Pond Turtle (R5 Sensitive)

In California, the western pond turtle, Actinemys marmorata, can be found on all national forests, 

except the Inyo and Lake Tahoe Basin. Few turtle-specific surveys have been conducted in the 

Tahoe National Forest. Primarily, northwestern pond turtle observations have been made during 

aquatic surveys or other forest activity surveys. Western pond turtles have been observed at 

approximately 28 locations within the Tahoe National Forest boundary. Fourteen of these locations 

are on National Forest System lands. The remaining locations are on private or Bureau of Land 

Management lands. All Tahoe National Forest recorded sightings are from the Yuba River drainage. 

Most of the observations have been associated with pond habitats, although several observations 

were of turtles walking distant from an aquatic habitat (e.g., turtle walking across a road).

Western pond turtles have significantly declined in number with many populations representing less 

than 10 percent of the historical population. In California alone, there has been a loss of 80 to 

85 percent of western pond turtles since the 1850s. The major threat to this species is habitat loss or 

degradation. Most of the historical habitat for this species has been permanently lost as a result of 

development for human occupancy.

Foothill Yellow-legged Frog (R5 Sensitive)

Foothill yellow-legged frogs (Rana boylii) have suffered significant population declines across the 

majority of their known range of southwestern Oregon west of the Cascades Mountains crest south 

through California to Baja California (Fellers 2005; Jennings and Hayes 1994). Populations of 

foothill yellow-legged frogs in the Pacific Northwest are considered to be the most stable with 

approximately 40 percent of streams occupied, 30 percent are occupied in the Casade Mountains, 

30 percent in the south Coast Range south of San Francisco and 12 percent in the Sierra Nevada 

foothills (Fellers 2005).

On the Tahoe National Forest, foothill yellow-legged frog surveys have been conducted in 

cooperation with the USGS Biological Division, Pt. Reyes from 1997 through 2000. In addition, 

California Academy of Sciences, San Francisco, has conducted herpetological surveys including 

areas likely to provide habitat for mountain yellow-legged frogs (1997, 1998, and 1999). Amphibian 

occurrence is documented during fish stream surveys and incidental to various other field activities 

and surveys. Although species-specific surveys for foothill yellow-legged frog are limited on the 

forest, this species tends to be easily observed during stream surveys and sightings are recorded. 

Perennial streams or intermittent streams with perennial pools and ponds below 6,000 feet in 

elevation on the west slope of the Sierra Nevada should be considered suitable for foothill yellowlegged frogs.

Sierra Nevada Yellow-legged Frog (USFWS Endangered)

The Sierra Nevada yellow-legged frog, Rana sierra, can be found on the El Dorado, Inyo, Lassen, 

Plumas, Sierra, Stanislaus, Tahoe and Lake Tahoe Basin National Forests. This species is found from 

around 4,500 feet to over 12,000 feet elevation, and inhabit ponds, lakes, and streams of sufficient 

depth for overwintering (Jennings and Hayes 1994).

Once abundant in aquatic ecosystems of the mid to high elevation Sierra Nevada from southern 

Plumas County to southern Tulare County (Jennings and Hayes 1994), the mountain yellow-legged 

frog has undergone a range-wide decline in the Sierra Nevada (USFWS 2003). Over 90 percent of 

historically occupied sites in the Sierra Nevada are now unoccupied (Vredenburg et al. 2007). 

The decline of mountain yellow-legged frogs in the Sierra Nevada has largely been attributed to the 

introduction of salmonid fishes during the last century (USFWS 2003). More recently, the disease 
Over-snow Vehicle Use Designation

Tahoe National Forest

260

chytridiomycosis has emerged as a significant threat to the species (Briggs et al. 2005, Oullet et al. 

2005, Wake and Vredenburg 2008).

Sierra Nevada yellow-legged frogs are known to have been present within a number of locations in 

the Tahoe National Forest, but now exist in only a few populations in ponds and streams and 

generally in small numbers (USFWS 2003, the Tahoe National Forest GIS database). The Tahoe 

National Forest GIS database shows that since 1993 there have been mountain yellow-legged frogs 

documented in 4 general localities on Truckee Ranger District, 6 general localities on Sierraville 

Ranger District, and 10 general localities on Yuba River Ranger District.

Lahontan Cutthroat Trout (USFWS Threatened)

The USFWS is in the process of revising the 1995 Recovery Plan for Lahontan cutthroat trout, 

Siphatales bicolor pectinifer. A technical team has assembled to develop restoration and recovery 

actions for the Truckee River basin. A primary purpose of the team is to identify and prioritize 

actions for the improvement of ecosystem function to facilitate the restoration and recovery of 

Lahontan cutthroat trout. 

Important recovery areas 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 Truckee River Basin 

Implementation Team 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 Lahontan cutthroat trout

because they contain remnants of indigenous Truckee River Basin strains.

Within Tahoe National Forest, recovery populations of Lahontan cutthroat trout occur in one lake 

and five streams. Tahoe National Forest has designated the Independence Lake and Upper 

Independence Creek flowing into it as a Critical Aquatic Refuge. Management decisions and actions 

in a Critical Aquatic Refuge should reflect the unique and important nature of the aquatic and 

riparian resources in these areas. Periodically, stream surveys are conducted to determine Lahontan 

cutthroat trout population trends. All populations in Tahoe National Forest have been stable and vary 

in numbers at carrying capacity for the habitat in the streams, However, the populations are small 

and may not be large enough to support genetic diversity in the long term, and may be at risk for 

genetic drift and bottlenecks (Somer, CDFW, pers. comm., 2014).

Hardhead (R5 Sensitive)

Historically, hardhead, Mylopharodon conocephalus, have been regarded as a widespread and locally 

abundant species (Ayres 1854, Jordan and Evermann 1896, Evermann 1905, Rutter 1908, Murphy 

1947, Soule 1951, Reeves 1964). Hardhead are still widespread in the foothill streams, but their 

specialized habitat requirements, combined with widespread alteration of downstream habitats have 

resulted in isolation and localization of populations. These conditions increase the chance for 

localized extinctions. Hence, hardhead are less abundant than they once were, especially in the 

southern half of their range.

The Tahoe National Forest LRMP, as amended, does not provide specific management guidelines for 

this species. SNFPA standards and guidelines for Riparian Conservation Areas, listed under

California red-legged frog, provide for the needs of this species.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

261

Lahontan Lake Tui Chub (R5 Sensitive)

The Lahontan Lake tui chub, Siphatales bicolor pectinifer, 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. Populations of chub occurring in Stampede, Boca, and Prosser 

reservoirs may also be Lahontan Lake tui chub due to morphological similarities (Marrin and Erman 

1982, Moyle et al. 1995).

The Lake Tahoe population is the only confirmed population in the Sierra Nevada, with a probable 

population in Stampede, Boca, and Prosser Reservoirs in the Tahoe National Forest. 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. Surveys for this 

species have not been conducted in the Tahoe National Forest. Populations of plankton-feeding chub 

occur in Stampede, Boca, and Prosser Reservoirs; these may be Lahontan Lake tui chub due to 

morphological similarities (Marrin and Erman 1982, Moyle et al. 1995).

Great Basin Rams-horn Snail (R5 Sensitive)

Historically, the Great Basin rams-horn snail, Helisoma newberryi, 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 in the Tahoe National Forest. Suitable habitat occurs 

within slow segments of the Truckee and Little Truckee Rivers and their tributaries. 

Currently, this snail has not been sighted or surveyed for in the Tahoe National Forest. Suitable 

habitat occurs within slow-flowing segments of the Truckee and Little Truckee Rivers and associated 

tributaries.

California Floater (F5 Sensitive)

The current distribution of the California floater, Anodonta californiensis, indicates this species has 

probably been eliminated from much of its former range (Taylor 1981). The California floater has 

been reported to occur in locations adjacent to the Tahoe National Forest, but no occurrences have 

been documented on National Forest system lands within the boundary of the Tahoe National Forest.

Black Juga (R5 Sensitive)

The black juga, Juga nigrina, is restricted to the upper Sacramento system in California. The typelocality populations in Clear Creek, Shasta County, tributary to the Sacramento River, have been 

decimated by gold mining activities (Frest and Johannes 1995), but the species still persists in Clear 

Creek above the town of French Gulch, the epicenter for mining operations (Johannes 2010). The 

authors further concluded that this species has been extirpated from several sites based on its 

apparent absence at many historic sites in the upper Sacramento River system (Frest and Johannes 

1995)
Over-snow Vehicle Use Designation

Tahoe National Forest

262

Environmental Consequences Common to all Alternatives

Because the alternatives are very similar, with the same activities proposed, and the differences are 

mainly the spatial extent of OSV use, most of the effects are described in this section. The varying 

areas of authorized OSV use would result in mostly small differences in the degree of possible 

effects. Therefore, each alternative’s effects described below will mainly summarize the extent of 

aquatic resources affected, and provide the basis for determinations. 

Direct and Indirect Effects 

Direct impacts to fish, amphibians, and other aquatic species would be nonexistent to extremely rare 

as amphibians are typically dormant during the winter, and OSVs would have to travel through water 

to collide with fish and other aquatic species. Due to the infrequency of this occurring, direct impacts 

to fish, amphibians, and aquatic species are expected to be minor or discountable. 

Indirect impacts would include snow compaction and impaired water quality or pollutants entering 

waterways. 

Snow Compaction

Snow compaction could indirectly affect aquatic species through delayed snowmelt, affecting the 

hydrologic regime, and altering habitat or riparian vegetation and possibly leading to erosion and 

sediment into waterways.

Widespread snow compaction from cross-country OSV uses can affect melt patterns, and in turn, the 

hydrologic regime. Studies have found delayed snowmelt in areas compacted by snowmobiles versus 

areas of uncompacted snow (Keddy et al. 1979; Neumann and Merriam 1972). During spring 

snowmelt, these effects can reduce the ability of the snow to slow runoff. It is unknown how much 

OSV-related snow compaction would affect runoff rate and timing, but some studies suggest up to a 

2-week delay. Because snow compaction from off-trail cross-country use is currently not extensive 

on a watershed scale, measureable changes in hydrology are not expected (McNamara 2017).

Riparian vegetation important to aquatic species could be affected by snow compaction. Early spring 

growth of some plant species may be slowed or may not occur under an OSV trail; however, the 

current and proposed OSV trails are underlain by existing roads and trails that are already compacted 

and/or disturbed and little, if any, additional impacts are expected to the vegetation. Trail grooming 

on the Tahoe National Forest occurs over an existing road and trail network and does not alter 

landforms or result in significant soil disturbance that would change water flow patterns or quantities 

of surface water runoff. Trail grooming does not cause substantial impacts to water quality, 

perennial, intermittent or ephemeral streams, wetlands or other bodies of water (Hydrology report, 

McNamara 2017). 

Cross-country OSV use can affect woody riparian species by bending and breaking of branches by 

recreationists running over the branches (Neumann and Merriam 1972). This is most likely to occur 

with lower snow depths, such as the beginning of the winter season and before sufficient snow has 

accumulated to protect vegetation, and during spring snowmelt. Regenerating timber could also be 

affected by bending and breaking of leaders with inadequate snow depth. However, both the 

hydrology report (McNamara 2017) and botany report (Davidson 2017) concluded that vegetation 

trampling from snowmobiles and impacts to riparian resources from OSV use would be discountable 

and extremely unlikely to occur with adequate snowpack coverage. 

Disturbance to soil and vegetation by OSV use is reduced as snowpack depths increase. Damage to 

soil and low-growing vegetation is much more likely when OSV use occurs under low-snow
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

263

conditions (Greller et al. 1974, Fahey and Wardle 1998). Thus, the minimum snow depth 

requirements of all alternatives are expected to prevent or minimize damage to soil and vegetation 

(Botany Report, Davidson 2017). On the Tahoe National Forest, OSV travel on snow-free areas is 

prohibited in the current and proposed scenarios. By not allowing cross-country OSV use when and 

where there is not adequate snow depth, the Tahoe National Forest minimizes the possibility of direct 

damage to soils and ground vegetation. 

Similarly, the hydrology analysis (McNamara 2017) found that with adequate snow depth, crosscountry use of OSVs would have discountable effect on ground disturbance that could lead to 

erosion and sedimentation in streams or other waterbodies, and discountable effect on vegetation, 

especially along streams and other waterbodies. 

It further states “...off-trail OSV use would be generally dispersed and would not result in high 

concentration of OSV use on bare soil. Also, travel over bare soil can damage machines so is 

generally avoided by operators. With adequate minimum snow levels, this plan would result in no 

more than incidental soil erosion and therefore would not create water quality impacts to streams or 

waterbodies by introducing sediment in water runoff.”

These conclusions are generally attributed to the fact that OSV use on the Tahoe National Forest is 

considerably less than Yellowstone National Park, where detailed studies were conducted on OSV 

use and their potential effects to the aquatic environment and hydrologic regime. 

The number of snowmobiles that entered Yellowstone in 2003 and 2004 was 47,799 and 22,423,

respectively (Arnold and Koel 2006), all routed through a single trailhead. In comparison, the 2009

estimated seasonal day use of OSV Program trails across the Tahoe National Forest was around 

20,000 OSVs, spread over 6 trailheads. These visitations are spread across multiple trailheads and 

trail systems and do not all occur in the same location. As a result, OSV seasonal use levels at any 

Tahoe National Forest trailhead or trail system are considerably less than OSV use that occurred at 

Yellowstone National Park, and are considered very low. Since Yellowstone OSV use levels studied 

had not resulted in impaired water quality, due to much lower use numbers, it follows that the OSV 

use as proposed in the project area would not adversely affect water quality of snowmelt. 

There are no direct effects to aquatic species from snow compaction along designated OSV trails 

because aquatic species are not present. Outside the designated OSV trail corridors, dispersed crosscountry OSV travel is much less likely to compact snow with enough intensity and repetition to 

measurably or predictably affect ground vegetation or the hydrologic regime, and therefore, snow 

compaction is not considered further in this analysis as a reasonably foreseeable source of indirect 

effects to aquatic species.

Snow compaction may affect aquatic species habitat, if present, however, the magnitude, timing, and 

location affected are difficult to determine because of the large area designated for OSV use and its 

dispersed nature.

Pollutants

Emissions from over-snow vehicles, particularly two-stroke engines on snowmobiles, release 

pollutants including ammonium, sulfate, benzene, nitrogen oxides, ozone, carbon dioxide, carbon 

monoxide, aldehydes, polycyclic aromatic hydrocarbons and other toxic compounds into the air. A 

portion of these compounds may become trapped and stored in the snowpack, to be released during 

spring runoff. Four-stroke snowmobile engines produce considerably lower amounts of pollutants.
Over-snow Vehicle Use Designation

Tahoe National Forest

264

Some of the airborne pollutants would enter the snowpack and be released during snowmelt. Similar 

responses can be assumed to occur in aquatic species that ingest these compounds from snowmelt, 

although the compounds may undergo chemical changes while in the snowpack, confounding the 

predictability of effects. 

Airborne pollutants can enter the snowpack from both local and regional sources, including but not 

limited to vehicle emissions, dust storms, and smog. The concentrations of basic cations and acidic 

anions in the snowpack can be altered and, when released quickly during snowmelt, can temporarily 

lower the pH of surface waters in a process known as “episodic acidification” (Blanchard et al. 

1988).

Demonstrating that snowpack chemistry can be used as a quantifiable indicator of airborne pollutants 

from vehicular traffic, a correlation was shown between pollutant levels and vehicle traffic in 

Yellowstone National Park (Ingersoll et al. 1997). Ammonium and sulfate levels were consistently 

higher for the in-road snow compared to off-road snow, but nitrate concentrations did not decrease 

within a distance of 100 meters from the emission source; thus, the nitrate ion may be used to 

distinguish between local and regional emission sources (Ingersoll et al. 1997). Studying snow 

chemistry in Yellowstone National Park, Ingersoll (1998) found that concentrations of ammonium, 

nitrate, sulfate, benzene, and toluene were positively correlated with snowmobile use. Concentrations 

of ammonium were up to three times higher for the in-road snow compared to off-road snow. 

Concentrations decreased rapidly with distance from roadways.

Arnold and Koel (2006) also examined volatile organic compounds in Yellowstone National Park, 

and found that the snow in heavily used areas contained higher levels of benzene, ethylbenzene, mand p-xylene, o-xylene, and toluene compared with a control site only 100 meters from the traveled 

roadways. Even at the most heavily used area (Old Faithful) they found that the concentrations of 

volatile organic compounds were considerably below Environmental Protection Agency’s water 

quality criteria for these compounds. 

In situ water quality measurements (temperature, dissolved oxygen, pH, specific conductance, and 

turbidity) were collected; all were found within acceptable limits. Five volatile organic compounds 

were detected (benzene, ethylbenzene, m- and p-xylene, o-xylene, and toluene). The concentrations 

were found below EPA criteria and guidelines for the volatile organic compounds analyzed and were 

below levels that would adversely impact aquatic ecosystems (Arnold and Koel 2006).

Studying air quality and snow chemistry effects from snowmobiles in the Snowy Range, Wyoming, 

Musselman and Korfmacher (2007) found that heavier snowmobile use resulted in higher levels of 

nitrogen oxides and carbon monoxide, but ozone and particulate matter were not significantly 

different. When compared with air quality during the summer, they found that carbon monoxide 

levels were higher in the winter, but nitrogen oxides and particulate matter were higher in the 

summer. Air pollutants were well-dispersed and diluted by winds, and air quality was not perceived 

as being significantly affected by snowmobile emissions. Pollutant concentrations were generally 

low in both winter and summer. These results differ from those studies examining air pollution from 

snowmobiles in Yellowstone National Park. However, snow chemistry observations did agree with 

studies from Yellowstone National Park. Compared with off-trail snow, the snow sampled from 

snowmobile trails was more acidic with higher amounts of sodium, ammonium, calcium, 

magnesium, fluoride, and sulfate. Snowmobile activity apparently had no effect on nitrate levels in 

the snow.

In the winter, overwintering amphibians are typically hibernating. Airborne compounds would only 

be taken up by respiring species. Airborne pollutants normally disperse quickly in mountain 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

265

environments that are prone to windy conditions, such as the Sierra Nevada. The levels of OSV 

exhaust contaminants on the Tahoe National Forest (considerably less than those observed in 

Yellowstone National Park) are not expected to impair water quality (McNamara 2016). 

The available research on OSV pollutants (both airborne and in the snowpack) indicate that some 

effects to aquatic species may occur in the immediate vicinity of heavy use areas. Pollutants that 

become trapped in the snowpack are also concentrated in areas of heavy OSV use. 

Outside the designated OSV trail corridors, dispersed OSV travel is much less likely to contribute 

harmful contaminants with high enough levels and repetition to measurably or predictably affect 

aquatic resources, and therefore, is not considered in this analysis as a possible source of indirect 

effects.

Based on multi-year studies in Yellowstone National Park, researchers concluded that Yellowstone 

OSV use levels have not resulted in impaired water quality. Given that OSV use levels on the Tahoe 

National Forest at OSV trailheads are less than OSV use levels occurring at Yellowstone during the 

study period, it is determined that water quality is not impaired by the OSV Program (Hydrology 

report, McNamara 2016). 

There are few studies regarding effects of snowmobiles on aquatic biota but, Adams (1975)

addressed the effects of high levels of lead and hydrocarbons from snow machine exhaust on brook

trout, Salvelinus fontinalis. His study found that that high-level exposure to lead and hydrocarbon 

can lower activity levels and feeding. The alternatives of the project are expected to have 

discountable effects to water quality and fish because snowmobile use on the Tahoe National Forest 

is widely dispersed and does not occur at concentrations that have been shown to cause adverse 

effects to water quality or aquatic organisms. The results of the Adam’s study support this contention 

and state that the levels of hydrocarbons found in the study are “unrealistic for all but a few small 

lakes in well populated areas.”

Pollutants Effects Summary

The uptake of harmful pollutants is not expected to result in the death of any individual aquatic 

species on the Tahoe National Forest, based on the studies described, and the findings related to 

water quality impacts. Therefore, the level of effect to TEPS aquatic species from OSV pollutants is 

expected to be minimal, and would not result in loss of individuals. 

Based on findings on studies of OSV related effects to aquatic species and/or their habitat, adverse 

impacts to special-status fish and amphibians due to impaired water quality would be expected to be

less than significant.

In addition, effects are more likely to occur along designated OSV trails compared to areas open to 

cross-country OSV use because dispersed OSV travel is much less likely to contribute harmful 

contaminants with high enough levels and repetition to measurably or predictably affect aquatic 

resources.

Monitoring

Use of OSVs has not been extensively monitored on the Tahoe National Forest. However, a 

monitoring study completed in 2011 showed no impact to aquatic resources, riparian systems, or 

meadows, and suggests that OSVs have a low risk to aquatic resources under current use levels and 

levels of management. Monitoring of aquatic resources results are summarized in table 89. Impacts 
Over-snow Vehicle Use Designation

Tahoe National Forest

266

to watershed resources would be minimized by periodically visually monitoring native surface roads 

used as OSV trails during spring runoff to determine if additional road drainage is needed. Visual 

Monitoring of wet meadow areas, trail stream crossings, hill climb areas and other areas with 

sensitive resources and/or concentrated use would occur when snow depth is less than 24 inches 

periodically to determine if resource damage was occurring, which could prompt corrective actions.

Table 89. Tahoe National Forest 2011 OHV/OSV Monitoring and Management Program: 2011 Monitoring 

Results

Monitoring 

Accomplishments

Results Were Objectives and Success Criteria 

Met?

American River RD 

OSV Monitoring of 

Aquatic Resources

Groomed OSV routes along the Foresthill 

Divide were monitored for resource 

damage during low-snow conditions over 

wetlands, riparian areas, and streams. No 

resource damage to aquatic resources 

was observed. An exceptionally deep 

snow pack in winter/spring 2011 

contributed to the protection of aquatic 

resources.

Yes, monitoring determined OSV use 

in relation to aquatic resources. No 

effects to aquatic resources were 

identified and no management 

actions are needed.

Environmental Consequences

California Red-legged Frog (USFWS Threatened)

Direct and Indirect Effects (All Alternatives)

There would be no direct effects because OSV use would prohibited over areas with inadequate 

snow depth or areas exposed to bare ground that would cause resource damage as described in 36 

CFR part 261.15, therefore, no direct impacts to individuals would occur. 

Direct effects from OSV collision could occur from cross-country use when breeding occurs. 

However, the probability of collision is very low and considered discountable for the following 

reasons: 

1. R. draytonii breed at temperatures above freezing and in snow-free areas where OSV use is 

unlikely to occur. 

2. R. draytonii critical habitats on the Tahoe National Forest are not located in high OSV use 

areas. R. draytonii populations are typically found at elevations below 3,500 feet. 

3. R. draytonii typically breed in snow-free areas in pond and stream pools exceeding 0.7 meter

depths in areas away from any roads or trails and where OSV use would generally be 

dispersed and away from areas with inadequate snow depth or exposed ground that might 

cause resource damage. 

4. Alternatives vary minimum snow depth so some alternatives would protect aquatic habitats 

better than others by preventing the compaction of soil and vegetation which affects water 

quality. However, cross-country OSV operators avoid travel over bare ground and soil 

because it can damage their machines. 

Pollutants that are trapped and then later released during snowmelt may have some adverse effects;

however, the extent and direction of specific effects is unknown. Impacts to water quality are 

assessed in the Hydrology Section, which concluded that water quality is not impaired by the Tahoe 

National Forest OSV Project for any of the alternatives. For this reason, it is expected that pollutant 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

267

concentrations would be low enough that water quality would not be impaired for aquatic species, 

and thus it is likely that R. draytonii response would be discountable.

California Red-legged Frog Critical Habitat

There are a total of 2,246 acres of California red-legged frog critical habitat within the Tahoe 

National Forest. These acres are contained within the NEV-1 and PLA-1 critical habitat subunits (75 

FR 12816).

For alternatives 1 and 4 the total acres of designated critical habitat within areas open to crosscountry OSV use are the same at 930 acres or approximately 41 percent of the total acres of critical 

habitat on the Tahoe National Forest. Alternatives 2, 3, and 5 have no acres open to cross-country 

OSV use inside critical habitat on the Tahoe NF. For alternatives 2, 3, and 5, critical habitat is over 

5 miles in distance to the nearest open OSV use area (table 90). 

Table 90. Alternatives comparison of possible effects to California red-legged frog critical habitat on the 

Tahoe National Forest

California red-legged frog Alternative 

1 

Alternative 

2

Alternative 

3

Alternative 

4

Alternative 

5

Critical habitat (acres) within 

100 feet of OSV trails

0 0 0 0 0

Critical habitat (acres) within areas 

designated for cross-country OSV 

use

930 0 0 930 0

There are no proposed designated OSV trails within California red-legged frog designated critical 

habitat for any of the alternatives. Therefore, there would be no effect to aquatic breeding and 

aquatic non-breeding habitat within California red-legged frog critical habitat from OSV trail use.

California Red-legged Frog Suitable Habitat

Suitable habitat in relation to OSV trails and areas open to cross-country OSV use are shown in table 

91. In general, sutiable habitat was defined as streams and waterbodies below 5,200 feet in elevation 

and 300 feet around these water features.

Table 91. Alternatives comparison of possible effects to California red-legged frog suitable habitat on 

the Tahoe National Forest

California red-legged frog Alternative 

1

Alternative 

2

Alternative 

3

Alternative 

4

Alternative 

5

Suitable habitat (acres) within 100 

feet of OSV trails

40 330 40 91 40

Suitable habitat (acres) within 

areas designated for cross-country 

OSV use

48,212 2,065 4,908 48,212 2,082
Over-snow Vehicle Use Designation

Tahoe National Forest

268

Alternative 2 has the least amount of suitable habitat acrage within areas open to cross-country OSV 

use. However, the acrage of suitable habitat affected by OSV trails is high for alternative 2 relative to 

the other alternatives becauseit has a greater mileage of designated OSV trails within suitable habitat. 

It is highly unlikely that OSV use would adversely affect suitable habitat because OSVs are 

restricted to operating on the existing roadbed only, where California red-legged frog habitat does 

not exist.

There would be no construction of any structures that could impede or redirect flood flows, nor any 

ground surface modifications that could change drainage patterns, impervious surfaces, soil 

permeability, or other hydrological characteristics such as surface water volumes (McNamara 2017).

OSV use during the winter is not expected to result in habitat disturbance because restriction of OSV 

use that causes resource damage and establishing minimum snow depths in alternatives 2, 3, 4, and 5 

are expected to be sufficient to prevent contact between OSVs and the soil surface. Implementation 

of water quality best management practices outlined in Volume II of this DEIS, Appendix D, further 

ensure controls to avoid resource damage. Additionally, it is likely that most OSV owners would not 

ride with less than adequate snow depth to prevent damage to their OSVs. 

However, more direct studies examining snow depth and OSV use in relation to the potential effects 

to aquatic species or their habitat are needed. Continued monitoring procedures by recreation and 

forest staff, law enforcement, and Investigation Officers will further add to a better understanding of 

the relation between OSV use and aquatic species or their habitat.

Cumulative Effects - Alternative 1

The risks of cumulative effects from this alternative are very low because existing requirements of 

adequate snow depths for OSV use appear to be sufficient to protect the ground surface. There would 

continue to be only incidental ground disturbance, low risk of damage to vegetation, and other direct 

and indirect effects. As a result, there would be no change to cumulative watershed effects or 

equivalent roaded acres calculations for any watersheds under this alternative as described in the 

Hydrology section. There would be negligible effects from exhaust emissions stored in snowpack.

This alternative would not implement the recommended mitigation measures, and has the second 

highest amount of land area open to OSVs. However, this alternative appears to have adequate snow 

cover requirements to protect soils, water, and aquatic resources, and to protect vegetation in riparian 

areas. This alternative would not directly conflict with Forest Plan standards and guidelines, and 

would not result in irreversible or irretrievable effects to soil, water, aquatic, or riparian resources.

Cumulative Effects - Alternatives 2, 3, 4, and 5

Alternatives 2, 3, 4, and 5 are discussed together because they have minor differences in terms of 

possible effects to the species or their habitat.

Because there is a low risk of direct and indirect effects, the risks of cumulative effects from these 

alternatives are negligible. As a result of the alternatives ranging in 12 to 24-inch minimum snow 

depth for cross-country use and a 6- to -24-inch recommended minimum snow depth on trails, there 

would continue to be only incidental ground disturbance. As a result, there would be no change to 

equivalent roaded acres calculations for any watersheds under any alternative, and no change in 

detrimental cumulative watershed effects as described in the Hydrology section. Alternatives 2, 3, 4, 

and 5 would implement recommended mitigation measures. These alternatives would have adequate 

snow cover to protect soils, water, vegetation and aquatic habitats to prevent resource damage. These 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

269

alternatives would not directly conflict with Forest Plan standards and guidelines, and would not 

result in irreversible or irretrievable effects to soil, water, or vegetation of aquatic resources.

Sierra Nevada Yellow-legged Frog (USFWS Endangered) 

Direct and Indirect Effects (All Alternatives)

Direct effects would not occur during the majority of the OSV operating period because (1) OSV use 

is not allowed over snow-free areas that would cause resource damage to the underlying ground; and 

(2) R. sierrae overwinter underwater and are restricted to deep lakes (over 5 feet deep) that do not 

freeze solid in winter, and therefore, are not located in areas where OSV use would typically occur. 

Direct effects from OSV collision could occur from cross-country use during spring thaw when 

breeding occurs from April at lower elevations to June or July in high elevations. Adults can travel 

over ice or snow to reach preferred breeding sites early in the breeding season (USDA Forest Service

2014b). However, the probability of vehicle collision was considered low based on the following 

reasons:

1. R. sierrae typically breed in snow free areas away from any road or trails. Additionally, OSV 

use is generally dispersed away from areas with inadequate snow depth or exposed ground 

that might cause damage to R. sierrae habitat. 

2. Snow depth vary by alternatives, therefore some alternatives would protect aquatic habitats 

better than others by preventing compaction of soil and vegetation which affects water 

quality. However, cross-country OSV operators avoid travel over bare ground or soil because 

it can damage their machines.

Pollutants that are trapped and then later released during snowmelt may have some adverse effects. 

However, the extent and direction of these effects are unknown. Impacts to water quality was 

assessed in the Hydrology Section, which concluded that water quality is not impaired by this project 

for any of the alternatives. For this reason, it is expected that pollutant concentrations would be low 

enough that water quality would not be impaired for aquatic species, and thus it is likely that R. 

sierrae response would be discountable. 

Sierra Nevada Yellow-legged Frog Critical Habitat

There are a total of 99,882 acres of R. sierrae critical habitat within the Tahoe National Forest. These 

acres are contained within critical habitat subunits 2B, 2C, 2D and 2E (81 FR 59045).

Approximately 76,241 acres of critical habitatoccur within areas open to cross country OSV use 

under alternative 2. Alternatives 1 and 4 have similar acrages of critical habitat in areas open to OSV 

use, however the acres of critical habitat likely affected by OSV trails c is slightly higher under 

alternative 4. Alternative 5 has the lowest number of critical habitat acres within areas open to cross 

country OSV use (table 92). 
Over-snow Vehicle Use Designation

Tahoe National Forest

270

Table 92. Alternatives comparison of potential effects to Sierra Nevada Yellow-legged frog critical 

habitat on the Tahoe National Forest

Sierra Nevada Yellow legged 

Frog Critical Habitat

Alternative 

1

Alternative 

2

Alternative 

3

Alternative 

4

Alternative 

5

Critical habitat (acres) within 

100 feet of OSV trails 657 665 573 707 626

Critical habitat (acres) within areas 

designated for cross-country OSV 

use

84,795 76,241 47,520 84,846 33,125

In general, it is unlikely that OSV trail use would adversely affect critical habitat because OSVs are 

restricted to operating on the existing roadbed only. Further, OSV use during the winter is not 

expected to result in habitat disturbance because restriction of OSV use that causes resource damage 

(e.g., establishing minimum snow depths) are expected to be sufficient to prevent contact between 

OSVs and the soil surface. Implementation of water quality Best Management Practices outlined in 

Volume II, Appendix D, further ensure controls to avoid resource damage. Additionally, it is likely 

that most OSV owners would not ride with less than adequate snow depth to prevent damage to their 

OSVs. 

Sierra Nevada Yellow-legged Frog Suitable Habitat

Suitable habitat in relation to OSV trails and areas open to cross-country OSV use are shown in table 

93. In general, suitable habitat was defined using the Regional Suitable Habitat dataset, which was 

derived using streams, lakes, ponds reservoirs, and meadows within the species’ range or distribution 

as defined by Roland Knapp during the summer of 2014.

Table 93. Alternatives comparison of possible effects to Sierra Nevada yellow-legged frog suitable 

habitat on the Tahoe National Forest

Sierra Nevada Yellow-legged 

Frog suitable habitat

Alternative 

1

Alternative 

2

Alternative 

3

Alternative 

4

Alternative 

5

Suitable habitat (acres) within 100 

feet of OSV trails

301 342 299 327 292

Suitable habitat (acres) within areas 

designated for cross-country OSV 

use 

30,750 23,212 17,320 30,949 15,600

Alternative 5 would have the least amount of potential effects to Sierra Nevada yellow-legged frog 

suitable habitat because it would affect the least amount of acres open to cross country OSV use and 

has the least number of OSV trails within suitable habitat.

Construction of any structures would not occur that could impede or redirect flood flows, nor any 

ground surface modifications which could change drainage patterns, impervious surfaces, soil 

permeability, or other hydrological characteristics such as surface water volumes (McNamara 2017). 

OSV use during the winter is not expected to result in habitat disturbance because minimum snow 

depths and restriction of OSV use that causes resource damage are expected to be sufficient to 

prevent contact between OSVs and the soil surface. However, snow depth requirements vary by 

alternative, therefore alternatives requiring with the greatest snow depths (alternatives 3 and 5) 

would likely have the least risk to aquatic habitat impacts compared to the alternatives 1, 2, and 4, 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

271

with alternative 1 likely to have the greatest risk to Sierra Nevada yellow-legged frog aquatic habitat.

Implementation of water quality best management practices outlined in Volume II of this DEIS, 

Appendix D, further ensure controls to avoid resource damage. Additionally, it is likely that most 

OSV owners would not ride with less than adequate snow depth to prevent damage to their OSVs. 

However, more direct studies examining snow depth and OSV use in relation to the possible effects 

to aquatic species or their habitat are needed. Continued monitoring procedures by recreation and 

forest staff, law enforcement, and Investigation Officers will further add to a better understanding of 

the relation between OSV use and aquatic species or their habitat. 

Cumulative Effects - Alternative 1

Same as California red-legged frog description above.

Cumulative Effects - Alternatives 2, 3, 4, and 5

Same as California red-legged frog description above.

Western Pond Turtle (R5 Sensitive)

Direct and Indirect Effects (All Alternatives)

There would be no direct effects because OSV use would not be allowed over areas with inadequate 

snow depth or areas exposed to bare ground that would cause resource damage as described in 36 

CFR part 261.15, therefore, no direct impacts to individuals would occur. 

For western pond turtle, hatchlings emerge in the spring, during snowmelt. The short delay of 

snowmelt and colder soil temperatures from OSV-compacted snow would not likely delay or reduce 

western pond turtle emergence. The effects of snow compaction and OSV emissions are 

concentrated in areas of heavy use, such as along designated OSV trails. 

No western pond turtle occurrences are present within 100 feet of existing or proposed designated 

OSV trails; therefore, it is anticipated that there would be no measurable or predictable indirect 

effects to the occurrences.

Cumulative Effects - Alternative 1

Same as California red-legged frog description above.

Cumulative Effects - Alternatives 2, 3, 4, and 5

Same as California red-legged frog description above.

Lahontan Cutthroat Trout (USFWS Threatened)

Direct and Indirect Effects – (All alternatives)

There would be no direct effects to Lahontan cutthroat trout because OSV use would not be allowed

over areas with inadequate snow depth or areas exposed to bare ground that would cause resource 

damage as described in 36 CFR part 261.15, and OSVs would have to travel through water to collide 

with fish, therefore, no direct impacts to individuals would occur. Additionally, there are no areas of 

Lahontan cutthroat trout recovery populations in Independence Lake that are open to cross-country 

OSV use under any of the alternatives. 

There are no crossings of designated OSV roads with Lahontan cutthroat trout recovery populations 

in the Tahoe National Forest for the proposed action or any of the other alternatives.
Over-snow Vehicle Use Designation

Tahoe National Forest

272

Pollutants that are trapped and then later released during snowmelt could have some adverse indirect 

effects if in close proximity to Lahontan cutthroat trout occupied streams. However, the probability 

of this occurring and resultant pollutant concentration would be low because of the widely dispersed 

nature of cross-country OSV use in space and time. 

Impacts to water quality are assessed in the Hydrology section, which concluded that water quality is 

not impaired by the Tahoe National Forest OSV Use Designation Project for any of the alternatives. 

For this reason, it is expected that pollutant concentrations would be low enough that water quality 

would not be impaired for aquatic species, and thus, it is likely that Lahontan cutthroat trout response 

would be discountable.

Cumulative Effects - Alternative 1

Same as California red-legged frog description above.

Cumulative Effects - Alternatives 2, 3, 4, and 5

Same as California red-legged frog description above.

Foothill Yellow-legged Frog (R5 Sensitive)

Direct and Indirect Effects – (All alternatives)

There would be no direct effects as described in the California red-legged frog description above

with the following differences:

The probability of vehicle collision is very low and considered discountable for the following 

reasons: 

1. R. boylii breed at temperatures above freezing and in snow-free areas where OSV use is 

unlikely to occur. 

2. R. boylii on the Tahoe National Forest are not located in high OSV use areas (see map). R. 

boylii populations are typically found at elevations below about 6,000 feet. 

3. R. boylii typically breed in streams containing cobble-sized or larger rock substrates, which 

are areas generally avoided by OSV use since they are typically snow-free and in areas with 

inadequate snow depth or exposed ground that might cause resource damage. 

4. Cross-country OSV operators typically avoid travel over bare ground or soil because it can 

damage their machines. 

Compacted snow generally causes delayed snowmelt and increases the transfer of freezing 

temperatures to the ground due to reduced insulating air spaces (Keddy et al. 1979, Fahey and 

Wardle 1998, Davenport and Switalski 2006, Eagleston and Rubin 2012, Gage and Cooper 2013). 

For R. boylii, breeding occurs when snow begins to melt. The short delay of snowmelt and colder 

soil temperatures from OSV-compacted snow would not likely delay or reduce R. boylii. The effects 

of snow compaction and OSV emissions are concentrated in areas of heavy use, such as along 

designated OSV trails. No R. boylii frog occurrences are present within 100 feet of existing or 

proposed designated OSV trails; therefore, it is anticipated that there would be no meaningfully 

measurable or predictable indirect effects to R. boylii.

Cumulative Effects-(Alternative 1)

Same as California red-legged frog description above.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

273

Cumulative Effects – (Alternatives 2, 3, 4, and 5

Same as California red-legged frog description above.

Hardhead (R5 Sensitive)

Direct and Indirect Effects – (All Alternatives)

There would be no direct effects to hardhead because OSV use would not be allowed over areas with 

inadequate snow depth or areas exposed to bare ground that would cause resource damage as 

described in 36 CFR part 261.15 and OSVs would have to travel through water to collide with fish, 

therefore, no direct impacts to individuals would occur. 

Indirect effects are unlikely to occur because hardhead are typically found in undisturbed areas of 

larger middle and low-elevation streams up to 4,390 feet in elevation (Moyle and Nichols 1973, 

Moyle 1976). 

The effects of snow compaction and OSV emissions are concentrated in areas of heavy use, such as 

along designated OSV trails. No hardhead occurrences are present within 100 feet of existing or 

proposed designated OSV trails; therefore, it is anticipated that there would be no measurable or 

predictable indirect effects.

In addition, indirect effects to hardhead from cross-country OSV use are highly unlikely because of 

implementation of a required minimum snow depth, dispersed nature of cross-country OSV use, lack 

of hardhead presence close to designated OSV areas or routes and the conclusions of the hydrology 

analysis that little change is expected to soils, vegetation, or hydrology of aquatic habitats.

Cumulative Effects-(Alternative 1)

Same as California red-legged frog description above.

Cumulative Effects – (Alternatives 2, 3, 4, and 5)

Same as California red-legged frog description above.

Lahontan Lake Tui Chub (R5 Sensitive)

Direct and Indirect Effects – (All Alternatives)

There would be no direct effects to the Lahontan Lake tui chub because OSV use would not be 

allowed over areas with inadequate snow depth or areas exposed to bare ground that would cause 

resource damage as described in 36 CFR part 261.15 and OSVs would have to travel through water 

to collide with fish, therefore no direct impacts to individuals would occur.

Pollutants that are trapped and then later released during snowmelt could have some adverse indirect 

effects if in close proximity to the Lahontan Lake tui chub. However, the probability of this 

occurring and resultant pollutant concentration would be very low because of the widely dispersed 

nature of cross-country OSV use in space and time. Similar conclusions are supported by the 

hydrology analysis, which determined that pollutant concentrations from OSV use entering 

waterways would be low enough that water quality would not be impaired.

Indirect effects to the Lahontan Lake tui chub from cross-country OSV use are expected to be highly 

unlikely because of the dispersed nature of cross-country OSV use, lack of Tui chub presence close 

to OSV open use areas or routes and the conclusions of the hydrology analysis that little change is 

expected to soils, vegetation, or hydrology of aquatic habitats.
Over-snow Vehicle Use Designation

Tahoe National Forest

274

Cumulative Effects-(Alternative 1)

Same as California red-legged frog description above.

Cumulative Effects – (Alternatives 2, 3, 4, and 5)

Same as California red-legged frog description above.

Great Basin Rams-horn Snail (R5 Sensitive)

Direct and Indirect Effects – (All Alternatives)

Direct or indirect effects to Great Basin rams-horn snail from OSV use would likely not occur 

because OSV use is prohibited over bare ground that would cause resource damage as described in 

36 CFR part 261.15, and Great Basin rams-horn snail typically occurs in larger lakes and slow rivers 

and the probability of effects to individuals is highly unlikely and considered discountable. 

This snail has not been sighted in the Tahoe National Forest, though no specific surveys have been 

conducted on the forest. Limited information exists on their behavior and distribution during winter 

months and studies examining snow depth and OSV use in relation to the possible effects to aquatic 

species or their habitat is needed.

Cumulative Effects-(Alternative 1)

Same as California red-legged frog description above.

Cumulative Effects – (Alternatives 2, 3, 4, and 5)

Same as California red-legged frog description above.

California Floater (R5 Sensitive)

Direct and Indirect Effects – (All Alternatives)

Direct or indirect effects to California floater from OSV use would likely not occur because OSV use 

is prohibited over bare ground that would cause resource damage as described in 36 CFR part 

261.15, and California floater occurs in lakes and slow rivers where the probability of effects to 

individuals is highly unlikely and is therefore, considered discountable.

Cumulative Effects

There are no interrelated or interdependent actions, therefore, no cumulative effects would occur to 

California floater.

Black Juga (R5 Sensitive)

Direct and Indirect Effects – (All Alternatives)

Black juga would not be directly affected by current or proposed OSV uses because OSVs are not

authorized to operate over bare ground that would cause resource damage as described in 36 CFR 

part 261.15 where black juga may be present. 

Pollutants that are trapped and then later released during snowmelt may have some adverse effects;

however, the extent and direction of specific effects is unknown. It is expected that pollutant 

concentrations would be low enough that water quality would not be impaired, and thus, it is likely 

that Juga nigrina responses would not be noteworthy.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

275

Cumulative Effects-(Alternative 1)

Same as California red-legged frog description above.

Cumulative Effects – (Alternatives 2, 3, 4, and 5)

Same as California red-legged frog description above.

Determination Statements

California Red-legged Frog (Rana draytonii)

Although occurrences for R. draytonii are located within the proposed project area, proposed 

activities are not expected to adversely affect the population because authorized activities would 

occur at a time of year when the amphibians are hibernating and occurrences are located in areas 

with inadequate snow depth or areas exposed to bare ground that are prohibited from OSV use if 

they cause resource damage. For all alternatives, OSV use on the required minimum snow depths 

respectively is not expected to result in any meaningful measurable changes to soils, vegetation, or 

hydrology of their aquatic habitats. Therefore, the Tahoe National Forest OSV Use Designation

project may affect, not likely to adversely affect R. draytonii.

California Red-legged Frog (Rana draytonii) Critical Habitat 

Critical habitat for R. draytonii is located within the project area, proposed activities are not expected 

to adversely affect critical habitat because OSV use is prohibited over areas with inadequate snow 

depth or exposed ground that would cause resource damage under all of the alternatives and OSV use 

on required minimum snow depths in alternatives 2, 3, 4, and 5 are not expected to result in any 

changes to soils, vegetation, or hydrology of their aquatic habitats. Therefore, the Tahoe National 

Forest OSV Use Designation project may affect, not likely to adversely affect R. draytonii critical 

habitat.

Sierra Nevada Yellow-legged Frog (Rana sierrae) 

The proposed activities may adversely affect individuals because OSVs may collide with adults 

traveling over ice or snow during the early portion of the breeding season. However, the probability 

of vehicle collision is likely low because authorized activities would mostly occur at a time of year 

when the amphibians are likely hibernating. In general, thespecies’ breeding season occurs when 

temperatures are above freezing and breeding occurs in snow-free areas where OSV use is unlikely 

to occur.

The findings of the soils, hydrology, and botany reports concluded that OSV use is not expected to 

result in any meaningfully measurable changes to soils, vegetation, or hydrology. 

OSV use is prohibited over areas with inadequate snow depth or exposed ground that would cause 

resource damage under all of the alternatives. In addition, alternatives 2, 3, 4, and 5 have required 

minimum snow depths under which OSV use can operate that would provide further protection to the 

underlying ground or habitat.

Therefore, the Tahoe National Forest OSV Use Designation project may affect, likely to adversely 

affect R. sierrae based on the potential to directly impact individuals. 

Sierra Nevada Yellow-legged Frog (Rana sierra) Critical Habitat

Critical habitat for R. sierrae is located within the project area. Proposed activities are not expected 

to adversely affect critical habitat because OSV use is prohibited over areas with inadequate snow 
Over-snow Vehicle Use Designation

Tahoe National Forest

276

depth or exposed ground that would cause resource damage under all of the alternatives and OSV use 

on required minimum snow depths under alternatives 2, 3, 4, and 5 are not expected to result in any 

changes to soils, vegetation, or hydrology of their aquatic habitats. Therefore, the Tahoe National 

Forest OSV Use Designation project may affect, not likely to adversely affect R. sierrae critical 

habitat.

Lahontan Cutthroat Trout (Oncorhynchus clarkii henshawi) 

Although occurrences for O. clarkii henshawi are located within the project area, proposed activities 

are not expected to adversely affect the population because occurrences are located in areas with 

inadequate snow depth or exposed ground that would cause resource damage under all of the 

alternatives and OSV use on required minimum snow depths in alternatives 2, 3, 4, and 5 are not 

expected to result in any changes to soils, vegetation, or hydrology of their aquatic habitats. 

Therefore, the Tahoe National Forest OSV Use Designation project may affect, not likely to 

adversely affect O. clarkii henshawi.

Western Pond Turtle (Actinemys marmorata)

Because A. marmorata are not active and/or present during the period of OSV use, A. marmorata 

effects would be minimized by the prohibition of OSV use in areas that would cause resource 

damage and required minimum snow depths proposed in alternatives 2, 3, 4, and 5. OSV use is not 

expected to result in a trend toward Federal listing or loss of viability for A. marmorata. Therefore,

the Tahoe National Forest OSV Designation project may affect individuals, but is not likely to 

result in a trend toward Federal listing or loss of viability in the planning area.

Foothill Yellow-legged Frog (Rana boylii)

Because R.boylii are not active and/or present during the period of OSV use, R. boylii would not be 

directly affected. Indirect effects are expected to be minor, and all effects would be minimized by the 

prohibition of OSV use in areas that would cause resource damage (all alternatives) and the required 

minimum snow depths proposed in alternatives 2, 3, 4, and 5. OSV use is not expected to result in a 

trend toward Federal listing or loss of viability for R.boylii. Therefore, the Tahoe National Forest 

OSV Designation project may affect individuals, but is not likely to result in a trend toward 

Federal listing or loss of viability in the planning area.

Hardhead (Mylopharodon conocephalus)

Although occurrences for M. conocephalus are located within the project area, proposed activities 

are not expected to adversely affect the population because occurrences are located in areas with 

inadequate snow depth or areas exposed to bare ground that are prohibited from OSV use if they 

cause resource damage (all alternatives). For alternatives 2, 3, 4, and 5, OSV use on the respective 

required minimum snow depths is not expected to result in any changes to soils, vegetation, or 

hydrology of their aquatic habitats. Therefore, the Tahoe National Forest OSV Designation project 

may affect individuals, but is not likely to result in a trend toward Federal listing or loss of 

viability in the planning area.

Lahontan Lake Tui Chub (Siphatales bicolor pectinifer)

Although occurrences for S. bicolor pectinifer are located within the project area, proposed activities 

are not expected to adversely affect the population because occurrences are located in snow-free

areas with inadequate snow depths that are prohibited from OSV use if they cause resource damage 

(all alternatives). For alternatives 2, 3, 4, and 5, OSV use on the respective required minimum snow 

depths is not expected to result in any changes to soils, vegetation, or hydrology of their aquatic 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

277

habitats. Therefore, the Tahoe National Forest OSV Designation project may affect individuals, but 

is not likely to result in a trend toward Federal listing or loss of viability in the planning area.

Great Basin Rams-horn Snail (Helisoma newberryi)

Because H. newberryi are not active and/or present during the period of OSV use, the species would 

not be directly affected. Potential indirect effects are expected to be minor, and all effects would be 

minimized by prohibition of OSV use in areas with inadequate snow depth that would cause resource 

damage (all alternatives) and the required minimum snow depths proposed in alternatives 2, 3, 4, and 

5. OSV use is not expected to result in a trend toward Federal listing or loss of viability for H. 

newberryi. Therefore, the Tahoe National Forest OSV Designation project may affect individuals, 

but is not likely to result in a trend toward Federal listing or loss of viability in the planning 

area.

California Floater (Anodonta californiensis)

Because A. californiensis are not active and/or present during the period of OSV use, the species

would not be directly affected. Potential indirect effects are expected to be minor, and all effects 

would be minimized by prohibition of OSV use in areas with inadequate snow depth that would 

cause resource damage (all alternatives) and the required minimum snow depths proposed in 

alternatives 2, 3, 4, and 5. OSV use is not expected to result in a trend toward Federal listing or loss 

of viability for A. californiensis. Therefore, the Tahoe National Forest OSV Designation project may 

affect individuals, but is not likely to result in a trend toward Federal listing or loss of viability 

in the planning area.

Black Juga (Juga nigrina)

Direct impacts to J. nigrina would be extremely rare as OSVs would have to travel through water to 

harm J. nigrina. Due to the rarity of this occurring, the direct impacts to J. nigrina are considered 

discountable. Potential indirect effects are undetectable and unlikely to affect the species or alter its 

habitat, as described above. With no direct or indirect effects expected, there would be no cumulative 

effects to this species. Therefore, the Tahoe National Forest OSV Use Designation project may 

affect individuals, but is not likely to result in a trend toward Federal listing or loss of viability 

in the planning area.

Compliance with Relevant Laws, Regulations, Policies and Plans 

The proposed project effects on threatened, endangered, proposed, and sensitive aquatic species have 

been evaluated and measures taken to ensure that sensitive species do not become threatened or 

endangered because of Forest Service actions. 

All alternatives would maintain viable populations of all native and desired nonnative species and 

would be compliant with Forest Service Manual direction. All alternatives would also comply with 

the Tahoe National Forest Land and Resource Management Plan and the Sierra Nevada Forest Plan 

Amendment because sensitive aquatic species populations would remain viable and their habitats 

would be maintained.

Botany – Listed and Sensitive Species

Effects to special interest plants, research natural areas, special interest areas, and noxious weeds are 

addressed in the Other Botanical Resources section.
Over-snow Vehicle Use Designation

Tahoe National Forest

278

Consultation to Date

No previous consultation with the Fish and Wildlife Service has taken place for the proposed OSV 

designation.

The Fish and Wildlife Service is contacted on a regular basis to obtain a current list of threatened, 

endangered, and proposed species and critical habitats that may be present on the Tahoe National 

Forest. The most recent lists, from May 15, 2017, are maintained at the Supervisors Office. The 

following plant species are included:

• Calystegia stebbinsii (Stebbins’ morning-glory) – from the Sacramento office

• Fremontodendron californicum ssp. decumbens (Pine Hill flannelbush) – from the 

Sacramento office

• Orcuttia tenuis (slender Orcutt grass) – from the Reno office 

• Packera layneae (Layne’s butterweed) – from the Sacramento office

The threatened plant, Packera layneae, is known from two occurrences on serpentine/gabbro soils on 

the American River Ranger District. 

Three plants, Calystegia stebbinsii (endangered), Fremontodendron californicum ssp. decumbens 

(endangered), and Orcuttia tenuis (threatened) are not present and are not suspected to occur on the 

Tahoe National Forest. Therefore, they are not carried further into the effects analysis. 

An additional threatened species, Ivesia webberi, has been considered as potentially present during 

previous Tahoe National Forest project planning, but all known populations and its designated 

critical habitat units are outside the Tahoe National Forest. Therefore, Ivesia webberi and its critical 

habitat would not be affected and are not analyzed in detail.

The candidate species, Pinus albicaulis, exists on the Tahoe National Forest at high elevations, and is 

addressed as a Forest Service Sensitive Species.

Relevant Laws, Regulations, and Policy

Federal Law and Policy

Endangered Species Act. The Endangered Species Act of 1973 (16 U.S.C. 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 critical 

habitat for these species. Section 7 of the Endangered Species Act, as amended, requires the 

responsible Federal agency to consult the Fish and Wildlife Service and the National Marine 

Fisheries Service concerning threatened or endangered species under their jurisdiction. It is Forest 

Service policy to analyze impacts to threatened or endangered species to ensure management 

activities are not likely to jeopardize the continued existence of a threatened or endangered species, 

or result in the destruction or adverse modification of critical habitat for these species. This 

assessment is documented in a biological assessment.

Forest Service Manual and Handbooks (FSM/H 2670). Forest Service Sensitive 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 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

279

significant trend toward Federal listing or loss of viability. This assessment is documented in a 

biological evaluation.

Forest Service Manual 2670.32 (USDA Forest Service 2005) directs the forest to avoid or minimize 

impacts to species whose viability has been identified as a concern, and therefore, listed as sensitive 

by the Regional Forester. If impacts cannot be avoided, then the forest must analyze the significance 

of the potential adverse effects on the population or its habitat within the area of concern and on the 

species as a whole. Impacts may be allowed, but the decision must not result in a trend toward 

Federal listing.

Land and Resource Management Plan

Tahoe National Forest Land and Resource Management Plan as amended by the Sierra 

Nevada Forest Plan Amendment (USDA Forest Service 2001) and Sierra Nevada Forest Plan 

Amendment, Final Supplemental Environmental Impact Statement and Record of Decision 

(USDA Forest Service 2004). The LRMP states that all necessary steps will be taken to ensure that 

agency actions do not jeopardize the continued existence of these species, and that viable populations 

of sensitive plants will be maintained. Therefore, the forest has developed a sensitive plant program 

that provides an operational framework with an objective of maintaining a viable population of 

sensitive plant species by assuring that they receive full consideration in all forest planning and 

project efforts. There are no specific standards or guidelines for threatened, endangered, proposed, or 

sensitive (TEPS) plants.

Sierra Nevada Forest Plan Amendment. The January 2004 Record of Decision (ROD) for the 

Sierra Nevada Forest Plan Amendment (USDA Forest Service 2004) replaces the January 2001 

Record of Decision for the Sierra Nevada Forest Plan Amendment in its entirety. Detailed 

information including specific standards and guidelines for species management can be found in the 

Sierra Nevada Forest Plan Amendment Record of Decision and Final Supplemental Environmental 

Impact Statement. The standards and guidelines in the January 2004 Sierra Nevada Forest Plan 

Amendment ROD are incorporated by reference.

General Forest Service direction for sensitive species is summarized below:

1. Assist states in achieving their goals for conservation of endemic species.

2. As part of the NEPA process, review programs and activities, through a biological 

evaluation, to determine their potential effect on sensitive species.

3. Avoid or minimize impacts to species whose viability has been identified as a concern.

4. If impacts cannot be avoided, analyze the significance of potential adverse effects on the 

population or its habitat within the area of concern and on the species as a whole.

5. Establish management objectives in cooperation with the states when a project on National 

Forest System (NFS) lands may have a significant effect on sensitive species population 

numbers or distribution. Establish objectives for Federal candidate species, in cooperation 

with the Fish and Wildlife Service and the states.
Over-snow Vehicle Use Designation

Tahoe National Forest

280

Resource Indicators and Measures 

Resource indicators and measures shown in table 19 will be used to measure and disclose effects to 

botanical resources of of threatened, endangered, and proposed species and critical habitats related to 

OSV use designations and grooming trails for OSV use.

Table 94. Botanical resources indicators and measures for assessing effects 

Resource Element Resource Indicator Measure

Threatened, endangered 

and sensitive plants

Species presence Total acres on Tahoe National Forest

Acres in designated OSV areas

Acres in high-use OSV designated areas

Methodology 

This analysis uses ArcMap and relevant GIS data layers from the Tahoe National Forest. The GIS 

layers of proposed OSV designations and groomed trails were overlain with the TEPS plant data 

layers to identify areas where effects could occur. 

Table 95 lists Fish and Wildlife Service threatened, endangered or proposed plants and their critical 

habitats that may be present or are known within the planning area. The potential effects to each 

species were evaluated based on growth form, timing of important life cycle elements (i.e.,

emergence, flowering, seed production, germination, etc.), identified threats, important habitat 

components, and the expected interaction with disturbances associated with OSV use and snow trail 

grooming. 

This biological evaluation/biological assessment reviews the modified proposed action and

alternatives in sufficient detail to determine the level of effect that would occur to federally listed 

plants and Region 5 sensitive plant species. For sensitive species, one of four possible determinations 

is chosen based on the available literature, a thorough analysis of the potential effects of the project, 

and the professional judgment of the botanist who completed the evaluation. The three possible 

determinations are:

• No effect

• May affect individuals, but not likely to trend toward Federal listing or result in the loss of 

viability in the planning area of the Tahoe National Forest

• May affect individuals, and likely to trend toward Federal listing or result in the loss of viability 

in the planning area of Tahoe National Forest

Similar categories for federally listed threatened and endangered species and critical habitats are:

• No effect

• May affect, but is not likely to adversely affect

• May affect, and is likely to adversely affect

Information used in this analysis includes pertinent scientific literature, project-specific botanical 

data, results of surveys and site revisits, and GIS layers of the following data: project boundary, 

actions by alternative, Tahoe National Forest TEPS plant occurrences, and critical habitat 

information from the Fish and Wildlife Service.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

281

Assumptions Specific to the TEPS Plant Analysis

• Plants are unlikely to be directly affected by authorized OSV use (with the specified 

requirements of specific snow depths or adequate snow depth to avoid damage to resources –

typically 12 inches) when their living tissues are not present above ground. Therefore, only shrub 

or tree species are likely to be directly affected by OSV use.

• Indirect effects, such as those possibly resulting from snow compaction and vehicle emissions, 

are likely to be concentrated in high-use areas. Therefore, an area within one-half mile of 

designated OSV trails is assumed to be affected by snow compaction and vehicle emissions.

Because OSV use is expected to be concentrated in designated OSV trail corridors, and 

grooming activities are restricted to identified trails, plants in areas designated for OSV use

outside these concentrated use corridors are much less likely to experience measurable indirect 

effects.

• Only authorized OSV uses will be analyzed. Concerns arising from unauthorized uses will be 

addressed as law enforcement issues and may prompt corrective actions. 

Spatial and Temporal Context for Effects Analysis

Direct/Indirect Effects Boundaries

The spatial boundary for analyzing the direct and indirect effects to TEPS plants is the project area 

boundary, because all expected effects relevant to these resources would occur and remain within 

this area. Effects to vegetation would be expected to have occurred or become evident within one or 

two years of disturbance and this constitutes the short term. Effects that linger beyond 2 years are 

considered long-term effects, and may extend to decades or centuries. Such long-term effects beyond 

20 years become increasingly difficult to predict due to unknown interactions and the many 

environmental variables with numerous possible outcomes.

Cumulative Effects Boundaries

Because effects from the proposed activities would interact with effects from other ongoing or future 

projects only within the project area boundary, the cumulative effects boundary is also the project 

area boundary. Cumulative effects are considered for a time period within 20 years of project 

implementation.

Affected Environment

Species Considered in the Analysis

Table 95. Threatened, endangered or proposed plant species considered

Scientific Name

Common Name

Habitat Species 

present?

Habitat 

present?

Effects analysis 

needed?

Threatened Plants

Calystegia stebbinsii 

Stebbin’s morningglory

Endangered

600-3,600 feet; chaparral or 

cismontane woodland on gabbroic or 

serpentinite substrates. Perennial 

herb.

No No

No. No Effect. 

Species is not 

suspected to 

occur in project 

area.
Over-snow Vehicle Use Designation

Tahoe National Forest

282

Scientific Name

Common Name

Habitat Species 

present?

Habitat 

present?

Effects analysis 

needed?

Fremontodendron 

californicum ssp. 

decumbens 

Pine Hill flannelbush

Endangered

1,400-2,500 feet; chaparral or 

cismontane woodland on gabbroic or 

serpentinite, rocky substrates. Shrub.

No No

No. No Effect. 

Species is not 

suspected to 

occur in project 

area.

Ivesia webberi

Webber’s ivesia 4,500-6,500 feet; shallow clay soils in 

Lassen, Plumas, Sierra, Washoe, and 

Douglas Counties in CA and NV. 

No No

No. No Effect. 

Species is not 

suspected to 

occur in project 

area.

Orcuttia tenuis

Slender Orcutt grass

Threatened

Vernal pools, in oak and/or pine 

woodlands. Below 5,800 feet. Critical 

habitat is designated, but is not 

present on the forest.

No No

No. No Effect. 

Species is not 

suspected to 

occur in project 

area.

Packera layneae

Layne’s butterweed

Threatened

650-3,600 feet; Tuolumne - Nevada 

counties; ultramafic soils (gabbro & 

serpentine); chaparral, conifer forest 

or woodland edges/openings.

Yes Yes Yes

Sensitive Plants

Astragalus lemmonii

Lemmon’s milkvetch

4,000-7,000 feet in California; east of 

Sierra crest; lakeshores, meadows & 

seeps among Great Basin scrub.

No Potential Yes

Astragalus pulsiferae 

var. coronensis

Modoc Plateau milkvetch

4,400-6,200 feet; Modoc – Plumas 

and Sierra Counties; Sandy or 

gravelly soils, often with juniper, pine 

or sagebrush. 

No Potential Yes

Astragalus webberi

Webber’s milkvetch

2,400-4,100 feet; known only from 

Plumas County; dry forest 

openings/edges & semi-disturbed 

areas. Perennial herb.

No Potential Yes

Boechera rigidissima

(Arabis rigidissima var. 

demota) 

Galena Creek 

rockcress

Above 7,500 feet; known only in 

Placer County, California and 

Washoe County, Nevada; mesic 

areas (sometimes rocky) at red fir 

forest to aspen/meadow transitions. 

No Potential Yes

Botrychium ascendens

upswept moonwort

Above 4,000 feet (generally 5,000-

7,500 feet on TNF); wet habitats 

(riparian, seeps, meadows, etc.). 

Yes Yes Yes

Botrychium crenulatum

scalloped moonwort

Above 4,000 feet (generally 5,000-

7,500 feet on TNF); wet habitats 

(riparian, seeps, meadows, etc.). 

Yes Yes Yes

Botrychium lunaria

common moonwort

Above 6,000 feet; wet habitats 

(riparian, seeps, meadows, etc.). 

No Potential Yes

Botrychium 

minganense 

Mingan moonwort

Above 4,000 feet (generally 5,000-

7,500 feet on TNF); wet habitats 

(riparian, seeps, meadows, etc.). 

Yes Yes Yes

Botrychium montanum

western goblin

Above 4,000 feet; wet habitats 

(riparian, seeps, meadows, etc.). 

No Potential Yes
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

283

Scientific Name

Common Name

Habitat Species 

present?

Habitat 

present?

Effects analysis 

needed?

Bruchia bolanderi

Bolander’s bruchia

Above 5,000 feet; montane 

meadows, stream banks, drying lake 

beds; on bare, semi-disturbed wet 

soils where competition is minimal.

Bryophyte, Moss (perennial).

Yes Yes Yes

Cudonia monticola

large cudonia

No elevation restriction, in duff; 

usually within old-growth conifer 

forests. Fungi (perennial).

No Potential Yes

Cypripedium 

fasciculatum

clustered lady's-slipper

Below 6,000 feet; mesic, mid-to latesuccession conifer or coniferhardwood forests; north aspects; 

sometimes found with yew. 

Yes Yes Yes

Cypripedium 

montanum

mountain lady'sslipper

1,500-6,500 feet; mesic to wet, midto late- succession conifer or coniferhardwood forests; north aspects; 

often found under montane dogwood. 

No Potential Yes

Dendrocollybia 

racemosa 

branched collybia

No elevation restriction; on decayed 

fungi or occasionally in duff; usually 

within old growth conifer or coniferhardwood forests. Fungi (perennial)

No Potential Yes

Erigeron miser

starved daisy

6,200-8,500 feet; known only from 

Placer and Nevada counties; gravelly 

soils in crevices of near-vertical 

granite cliffs/faces.

Yes Yes Yes

Eriogonum 

umbellatum var.

torreyanum 

Donner Pass 

buckwheat

Above 6,800 feet; dry, unstable, 

gravelly or stony soils; often on harsh 

exposures (e.g., ridge tops, steep 

slopes).

Yes Yes Yes

Fritillaria eastwoodiae

Butte County fritillary

Below 4,900 feet; full to partial sun; 

chaparral, woodland and conifer 

forest. 

Yes Yes Yes

Helodium blandowii

Blandow’s bog moss

Above 6,100 feet in California; usually 

found in bogs and fens, but 

sometimes seeps, wet meadows and

under willows in riparian. Bryophyte, 

Moss.

No Potential Yes

Ivesia aperta var. 

aperta

Sierra Velley ivesia

5,000-6,000 feet; east of Sierra crest; 

known only from Sierra and Dog 

Valleys; meadow edges, ephemeral 

stream channels, vernally wet flats & 

gentle, rocky slopes near springs. 

No Potential Yes

Ivesia aperta var. 

canina

Dog Valley ivesia

5,000-6,000 feet; east of Sierra crest; 

known only from Dog Valley; meadow 

edges, ephemeral stream channels, 

vernally wet flats and gentle, rocky 

slopes near springs. 

No Potential Yes

Ivesia sericoleuca

Plumas ivesia

5,000-6,500 feet; east of Sierra Crest; 

Plumas and Placer counties; vernally 

wet meadows and alkali flats. 

Yes Yes Yes
Over-snow Vehicle Use Designation

Tahoe National Forest

284

Scientific Name

Common Name

Habitat Species 

present?

Habitat 

present?

Effects analysis 

needed?

Juncus luciensis

Santa Lucia dwarf 

rush

4,500-6,300 feet; known only from 

southern California coast, Modoc 

Plateau and eastern Nevada County; 

wet, sandy soils of seeps, meadows, 

vernal pools, streams, & roadsides.

No Potential Yes

Lewisia cantelovii

Cantelow's lewisia

1,000-4,500 feet; known only from 

Yuba River drainage; wet rock cliffs 

and outcrops; usually with moss or 

club moss. 

Yes Yes Yes

Lewisia kelloggii ssp. 

hutchisonii 

Hutchison’s lewisia

4,800-7,000 feet; ridgetops or 

relatively flat open areas; generally 

full sun; gravelly soils.

Yes Yes Yes

Lewisia kelloggii ssp.

kelloggii

Kellogg’s lewisia

Above 6,500 feet; ridgetops or 

relatively flat open areas; generally 

full sun; gravelly or sandy soils.

Yes Yes Yes

Lewisia longipetala

long-petaled lewisia

Above 8,300 feet; El Dorado –

Nevada counties; north-facing slopes 

and ridge tops often found in wet soils 

near margins of persistent snow 

banks. 

Yes Yes Yes

Lewisia serrata

saw-toothed lewisia

3,000-5,000 feet; known only from 

American River drainage; wet rock 

cliffs and outcrops; usually with moss. 

Yes Yes Yes

Meesia uliginosa 

broad-nerved hump 

moss

Above 6,000 feet; usually found in 

bogs or fens, but also very wet 

meadows. Bryophyte, Moss 

Yes Yes Yes

Mielichhoferia 

elongata

elongate copper-moss

Below 3,500 feet; soils with copper or 

heavy metals; moist to wet rock 

cliffs/outcrops. Bryophyte, Moss 

No Potential Yes

Monardella follettii

Follett's monardella

2,500-5,600 feet; known only from 

Plumas County; serpentine soils; 

partial to full sun; conifer forest 

edges/openings. 

No Potential Yes

Peltigera gowardii

Goward’s waterfan

1,150-7,000 feet, cold, clear, 

unpolluted streams; often found on 

rocks in cascades. Aquatic jelly lichen 

No Potential Yes

Penstemon 

personatus

closed-throated 

beardtongue

4,500-6,500 feet; Plumas – north 

Nevada County; partial sun; north 

aspects; conifer forest edges and 

openings.

Yes Yes Yes

Phacelia stebbinsii

Stebbins’ phacelia

2,000-6,700 feet; known only in 

Rubicon and American River 

drainages partial to full sun; generally 

in rocky openings/outcrops, but also 

woodland or conifer forest 

edges/openings. 

Yes Yes Yes

Phaeocollybia olivacea

olive phaeocollybia

No elevation restriction; Yuba County 

and north; on roots of Pinaceae and 

Fagaceae; usually within old growth 

conifer or conifer-hardwood forests.

Fungi 

No Potential Yes
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

285

Scientific Name

Common Name

Habitat Species 

present?

Habitat 

present?

Effects analysis 

needed?

Pinus albicaulis

whitebark pine

Above 6,500 feet on TNF; subalpine 

and at timberline on rocky, welldrained soils. Coniferous tree.Yes Yes Yes

Poa sierra

Sierra bluegrass

1,000-5,500 feet; shady moist slopes; 

conifer forest edges/openings. Yes Yes Yes

Pyrrocoma lucida

sticky pyrrocoma

4,500-6,000 feet on TNF; east of 

Sierra crest; known only from Plumas 

and Sierra Counties; vernally wet 

meadows and alkali flats.

Yes Yes Yes

Sowerbyella rhenana 

stalked orange-peel 

fungus

No elevation restriction; in duff; wet 

mossy areas; usually within oldgrowth conifer forests. Fungi 

No Potential Yes

Tauschia howellii

Howell’s tauschia

5,500-8,500 feet in California; xeric 

ridge summits and slopes; 

decomposed granite gravel or sand; 

red fir and subalpine forest 

edges/openings. 

Yes Yes Yes

Threatened Species Information

Packera layneae (Layne’s butterweed)

Status and Distribution

Layne’s butterweed, a perennial herb, is listed by the Fish and Wildlife Service as a threatened 

species (USFWS 1996). It is known from several localities within the foothills of El Dorado, 

Tuolumne, and Yuba Counties (USFWS 2002) and in Placer County near Foresthill, California. The 

latter occurrence in Placer County is located just west of Sage Hill, on the Tahoe National Forest.

This occurrence covers approximately 11 acres on open, gabbro soils at approximately 3,600 feet 

elevation, and includes about 100 plants in widely scattered clumps. 

This early seral species occurs in temporary openings in chaparral plant communities on gabbro and 

serpentine soils and “is eliminated as vegetation grows up around it” (USFWS 2002). Based on the 

associated plant community and management history of the local population of this species near 

Sage Hill, Layne’s butterweed appears adapted to a slight to moderate degree of disturbance (i.e.,

processes such as wildland fire that result in early seral vegetation).

Habitat loss, habitat fragmentation, alteration of natural fire regime, and suppression of disturbance 

(all mainly due to urbanization) are the major threats facing this species (USFWS 2002). In this 

project area, because of its relatively low elevation, Layne’s butterweed occurrence does not 

consistently receive enough snowfall to allow OSV use on a regular basis. 

Sensitive Species Information

Aggregating Species for Analysis of Effects

Due to the large number of sensitive plant species to address, and because OSV effects to various 

plant species are expected to be most similar according to their life form and growth habits, the 

39 sensitive species considered in this analysis are grouped into the following categories:
Over-snow Vehicle Use Designation

Tahoe National Forest

286

• Trees, shrubs, or sub-shrub species, whose living tissues may be present above or within the 

snow column, and thus, may experience direct effects from OSV uses (physical damage or 

immediate exposure to exhaust). On the Tahoe National Forest, Eriogonum umbellatum var. 

torreyanum, Monardella follettii, and Pinus albicaulis are the sensitive plants in this category.

• Perennial herbaceous species, including grasses, mosses, and in this case, fungi, whose living 

tissues are at or below the soil surface in winter, and thus, are unlikely to experience direct 

effects, but they will be evaluated for impacts by exhaust contaminants trapped by the snow 

cover or by possible effects from snow compaction. On the Tahoe National Forest, there are 

34 sensitive plants in this category.

• Annual plant species are generally not growing during the period of authorized OSV use, and 

thus would not experience direct effects. This group is the least likely to be impacted by the 

indirect effects of exhaust contaminants and snow compaction. Phacelia stebbinsii is the only 

annual sensitive plant on the Tahoe National Forest.

• Aquatic plant species grow under water and would not be directly affected by OSV use. If an 

occurrence is located in high-use areas, it is possible that snowpack contaminants could reach the 

occupied aquatic habitat when the snow melts. Snow compaction is not expected to affect 

aquatic habitats in any meaningful or predictable manner. Although many sensitive plants may 

be found in wet habitats, Peltigera gowardii is the only aquatic species.

Environmental Consequences

Effects common to all alternatives

Because the alternatives are very similar, with the same activities proposed, and the differences are 

mainly the spatial extent of OSV use, most of the effects are described in this section. The varying 

areas of authorized OSV use would result in mostly small differences in degree of possible effects. 

Therefore, each alternative’s effects will mainly summarize the extent of TEPS plants affected, and 

provide the basis for determinations. A summary comparison of alternatives will follow, providing 

the decision-maker a quick reference for evaluating the alternatives along with the other resources 

that need to be considered. 

Effects analyses for TEPS plants are presented in categories of plant life forms because the greatest 

possible impacts from OSV activities are dependent upon the presence of their living tissues within 

the snow or above the snow surface and whether each species is biologically active during the times 

that direct and indirect effects may occur. Effects to each life form category are presented after an 

introduction of direct and indirect effects. 

Direct Effects

Direct effects are caused by the action and occur at the same time and place. A key difference 

between OSV use and other types of motor vehicle use is that, when properly operated and managed, 

OSVs do not make direct contact with soil, water, and ground vegetation, whereas most other types 

of motor vehicles operate directly on the ground (USDA Forest Service 2014). OSV use and 

grooming of OSV trails can damage vegetation through direct contact with plant tissues that are 

present above the snow or within the snow column that is compacted by the vehicles. Because 

woody species (trees, shrubs, and sub-shrubs) are the only plants present within the snow, they are 

the only plants that may be directly damaged. All other plant life forms are not expected to be 

directly affected by OSV use because adequate snow requirements and minimum snow depths are 

expected to prevent direct effects to vegetation at ground level.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

287

It is generally recognized that disturbance to soil and vegetation by OSV use is reduced as snowpack 

depths increase. Damage to soil and low-growing vegetation is much more likely when OSV use 

occurs under low-snow conditions (Greller et al. 1974, Fahey and Wardle 1998). Thus, the 

requirement of adequate snow to avoid damage to resources for alternative 2, and the specific 

minimum snow depths for alternatives 3, 4, and 5 are expected to prevent or minimize damage to soil 

and vegetation.

In a study on Niwot Ridge in the Front Range of the Colorado Rocky Mountains, repeated 

snowmobile use occurred on snow-covered and snow-free areas between two weather stations, and 

the effects of this use were evaluated (Greller et al. 1974). General conclusions included: (1) in 

communities that are snow-free in winter, damage by snowmobiles was severe to lichens, 

Selaginella, and to relatively prominent, rigid cushion-plants. Part of the damage to these 

communities may have been due to the manual removal of rocks, necessary for the operation of 

snowmobiles in snow-free areas. (2) Kobresia, present in isolated tussocks in a cushion-plant 

community, absorbed the major portion of snowmobile impact. As Kobresia is thought to form the 

climatic climax community in this ecosystem, differential damage to it could seriously retard 

succession. (3) Snowmobile travel in uniform, closed Kobresia meadows inflicted much less damage 

to most plants, including Kobresia itself, than did similar travel on a sparsely vegetated community. 

(4) Plants best able to survive the heaviest snowmobile impact were those with small stature and 

little woodiness, or with buds well-protected at or below the soil surface. (5) Snowmobile traffic 

should be carefully restricted to snow-covered areas. Whenever this is not feasible, the least 

destructive and easiest alternative is travel on mature, well-vegetated Kobresia meadows or similar 

well-drained plant communities.

On the Tahoe National Forest, OSV travel on snow-free areas is prohibited in the current and 

proposed scenarios. By not allowing OSV use when and where there is less than adequate snow to 

avoid damage to resources (typically 12 inches for cross-country use) or designating specific snow 

depth requirements, the Tahoe National Forest minimizes the possibility of direct damage to soils 

and ground vegetation.

Indirect Effects 

Three specific topics of indirect effects were identified: snow compaction, pollutants, and invasive 

plant species. For areas designated for cross-country OSV use, these indirect effects are expected to 

be more dispersed and repeated less often than along trail corridors. There may be some meadows 

and other open areas where OSV use is more attractive to riders, and these may experience more 

concentrated use. However, OSV use has not been identified as a threat and is unlikely to cause 

damage to any non-woody TEPS plants in areas of dispersed use on the Tahoe National Forest.

Snow Compaction

Snow is compacted by any of the allowed OSVs, including snowmobiles, snowcats, and snow 

grooming equipment. Snow compaction mechanically alters snow grains and redistributes them. This 

mechanical disturbance breaks off the small points of new snow crystals, destroying the weak 

existing bonds between them, and bringing the new grains into much closer contact than occurs 

naturally. Snow metamorphism is artificially accelerated, and snow density and hardness are 

increased. In addition, the layered structure of the snowpack is changed (Fahey and Wardle 1998). 

All this has both thermal and hydrological implications, resulting in lower soil temperatures (Fahey 

and Wardle 1998, Eagleston and Rubin 2013) and delayed snowmelt (Keddy et al. 1979, Fahey and 

Wardle 1998, Davenport and Switalski 2006, Gage and Cooper 2013). The thermal conductivity of 

compacted snow is greater than undisturbed snow, and can reduce the buffering effect against 
Over-snow Vehicle Use Designation

Tahoe National Forest

288

temperature extremes and fluctuations. Thermal conductivity of compacted snow was 11.7 times 

greater than non-compacted snow (Neumann and Merriam 1972).

Keddy et al. (1979) studied the effects of snowmobile use on snow compaction, vegetation 

composition, and soil temperatures on an abandoned farm in Nova Scotia. They found that snow 

melted later in areas with compacted snow and that some species showed differences in cover 

between treatments. Considering the multitude of possible effects and the variety of plant structures 

and life histories, they were not surprised to find no overall trend for species composition changes. 

They also noted that the first pass by a snowmobile caused the greatest increase in snow 

compaction—roughly 75 percent of that observed after 5 sequential passes. While some species 

composition changes were observed in old field vegetation, they found no changes in species 

composition in a marsh area, possibly because of solid ice cover during the winter.

In a study of the impact of snowshoe/cross-country ski compaction and snowmelt erosion on 

groomed trails, Eagleston and Rubin (2013) reported that these non-motorized uses caused snow to 

remain on the compacted areas an average of 5 days longer than non-compacted areas. They also 

found that the compacted snow caused increased erosion. Soil temperatures under compacted snow 

stayed frozen for 3 days longer, and, averaged over the entire winter season, remained 0.1 degree 

Celsius colder than soil under non-compacted snow.

Fahey and Wardle (1998) examined the effects of snow grooming for downhill ski areas in subalpine 

and alpine environments. They found that the compacted snow increased frost penetration and 

delayed snowmelt.

However, research does not always support the generalization of lower soil temperatures and delayed 

snowmelt due to snow compaction. In a study of snow compaction effects from snowmobiles on fens 

on the Routt National Forest, Gage and Cooper (2009) found no statistically significant differences 

in the temperature of peat soils between compacted and non-compacted areas. They also found no 

differences in timing of snowmelt, biomass production, or plant phenology. From additional, 

unpublished data from the Telluride Ski Area, where intense compaction occurred daily, they 

observed a delayed snowmelt and thawing of the soil of about one month in compacted areas. They 

noted that the continuous influx of groundwater in fens may limit freezing and maintain more 

constant soil thermal conditions. They found no evidence conclusively linking snowmobile 

compaction to impairment of fen function.

Different plants have different levels of vulnerability and ability to recover from the effects of snow 

compaction. The characteristics that determine their vulnerability are the timing of flowering, and 

growth form and size (Fahey and Wardle 1998). Prolonged snow may adversely affect early spring 

flowering plants because they could have a shorter growing season and thus possibly reduced seed 

production due to delayed phenology and perhaps a misalignment of timing with their preferred 

pollinators. Due to snow compaction, early spring growth of some plant species may be retarded or 

may not occur under an OSV trail; however, the current and proposed OSV trails are underlain by 

existing roads and trails which are already compacted and/or disturbed and little, if any, additional 

impacts are expected to the vegetation.

Trail grooming on the Tahoe National Forest occurs almost entirely over an existing road and trail 

network and does not alter landforms or result in significant soil disturbance that would change water 

flow patterns or quantities of surface water runoff. Trail grooming is not expected to cause 

substantial impacts to water quality, perennial, intermittent or ephemeral streams, wetlands or other 

bodies of water. 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

289

In summary, the available research supports the assumption that more intensive snow compaction 

occurring along groomed or heavily used trails would have considerably greater effect on soil 

temperatures and delayed snowmelt than the compaction caused by dispersed uses in areas open to 

cross-country OSV use. Due to the intensive, repetitive, and predictable compaction of snow along 

designated OSV trails (groomed or not), these areas are much more likely to have a degree of 

compaction that could adversely influence vegetation. Therefore, in this analysis, areas within a half 

mile of designated OSV trails are assumed to be at risk from the effects of snow compaction. Outside 

the designated OSV trail corridors, dispersed OSV travel is much less likely to compact snow with 

enough intensity and repetition to measurably or predictably affect ground vegetation, and therefore,

is not considered in this analysis as an expected source of indirect effects.

Pollutants

Emissions from OSVs release pollutants including ammonium, sulfate, benzene, nitrogen oxides, 

ozone, carbon dioxide, carbon monoxide, aldehydes, polycyclic aromatic hydrocarbons and other 

toxic compounds into the air. A portion of these compounds may become trapped and stored in the 

snowpack, to be released during spring runoff. Four-stroke snowmobile engines produce 

considerably lower amounts of pollutants.

Pollutants emitted from exhaust can cause a variety of impacts on vegetation. Carbon dioxide may 

function as a fertilizer and cause changes in plant species composition (Bazzaz and Garbutt 1998); 

nitrogen oxides also may function as fertilizers, producing similar effects along roadsides 

(Falkengren-Grerup 1986). Sulfur dioxide, which can be taken up by vegetation, may result in 

altered photosynthetic processes (Winner and Atkison 1986, Mooney et al. 1988). Other toxic 

compounds may result in reduced metabolism or retarded growth.

Although a large portion of OSV exhaust is expected to be dissipated into the air, some of the 

airborne pollutants would enter the snowpack and be released during snowmelt. Similar responses 

can be assumed to occur in plants that ingest these compounds from snowmelt, although the 

compounds may undergo chemical changes while in the snowpack, confounding the predictability of 

effects.

Airborne pollutants can enter the snowpack from both local and regional sources, including, but not 

limited to, vehicle emissions, dust storms, and smog. The concentrations of basic cations and acidic 

anions in the snowpack can be altered and, when released quickly during snowmelt, can temporarily 

lower the pH of surface waters in a process known as “episodic acidification” (Blanchard et al.

1988). Soil acidification and vegetation changes were examined in southern Sweden, where 

Falkengren-Grerup (1986) found that increased nitrogen deposition and the increased acidity in the 

humus layer may have caused changes in plant cover, with some species increasing and some species 

decreasing.

Demonstrating that snowpack chemistry can be used as a quantifiable indicator of airborne pollutants 

from vehicular traffic, a correlation was shown between pollutant levels and vehicle traffic in 

Yellowstone National Park (Ingersoll et al. 1997). Ammonium and sulfate levels were consistently 

higher for the in-road snow compared to off-road snow, but nitrate concentrations did not decrease 

within a distance of 100 meters from the emission source; thus, the nitrate ion may be used to 

distinguish between local and regional emission sources (Ingersoll et al. 1997). Studying snow 

chemistry in Yellowstone National Park, Ingersoll (1998) found that concentrations of ammonium, 

nitrate, sulfate, benzene, and toluene were positively correlated with snowmobile use. Concentrations 
Over-snow Vehicle Use Designation

Tahoe National Forest

290

of ammonium were up to three times higher for the in-road snow compared to off-road snow. 

Concentrations decreased rapidly with distance from roadways.

Arnold and Koel (2006) also examined volatile organic compounds in Yellowstone National Park, 

and found that the snow in heavily used areas contained higher levels of benzene, ethylbenzene, mand p-xylene, o-xylene, and toluene compared with a control site only 100 meters from the traveled 

roadways. Even at the most heavily used area (Old Faithful) they found that the concentrations of 

volatile organic compounds were considerably below U.S. Environmental Protection Agency’s water 

quality criteria for these compounds. In situ water quality measurements (temperature, dissolved 

oxygen, pH, specific conductance, and turbidity) were collected; all were found within acceptable 

limits. Five volatile organic compounds were detected (benzene, ethylbenzene, m- and p-xylene, oxylene, and toluene). The concentrations found were below EPA criteria and guidelines for the 

volatile organic compounds analyzed and were below levels that would adversely impact aquatic 

ecosystems (Arnold and Koel 2006).

Studying air quality and snow chemistry effects from snowmobiles in the Snowy Range, Wyoming, 

Musselman and Korfmacher (2007) found that heavier snowmobile use resulted in higher levels of 

nitrogen oxides and carbon monoxide, but ozone and particulate matter were not significantly 

different. When compared with air quality during the summer, they found that carbon monoxide 

levels were higher in the winter, but nitrogen oxides and particulate matter were higher in the 

summer. Air pollutants were well-dispersed and diluted by winds, and air quality was not perceived 

as being significantly affected by snowmobile emissions. Pollutant concentrations were generally 

low in both winter and summer. These results differ from those studies examining air pollution from 

snowmobiles in Yellowstone National Park. However, snow chemistry observations did agree with 

studies from Yellowstone National Park. Compared with off-trail snow, the snow sampled from 

snowmobile trails was more acidic with higher amounts of sodium, ammonium, calcium, 

magnesium, fluoride, and sulfate. Snowmobile activity apparently had no effect on nitrate levels in 

the snow.

In the winter, plant metabolic rates are drastically reduced. Airborne compounds would only be taken 

up by respiring woody plants. Airborne pollutants normally disperse quickly in mountain 

environments that are prone to windy conditions, such as the Sierra Nevada. Different plants may 

have different responses to the different pollutants in the snowpack, including damage from toxic, 

volatile compounds and possibly some benefits from additional nutrients and trace minerals. The 

levels of OSV exhaust contaminants on the Tahoe National Forest (considerably less than those 

observed in Yellowstone National Park) are not expected to impair water quality (McNamara 2016). 

In a natural plant community with many species competing for resources, and very little research 

done on each species’ responses to OSV emissions or the competitive interactions that may be 

affected, it is nearly impossible to predict what changes, if any, would occur. It can only be 

reasonably assumed that there may be some changes in plant species cover and composition. The 

uptake of harmful pollutants is not expected to result in the death of any individual plants. On the 

Tahoe National Forest, mortality of roadside TEPS plants due to vehicle pollutants has not been 

observed, even considering year-round vehicle uses. Therefore, the level of effect to TEPS plants 

from OSV pollutants is expected to be minimal, and would not result in loss of individuals.

The available research on OSV pollutants (both airborne and in the snowpack) indicate that some 

effects to vegetation may occur in the immediate vicinity of heavy use areas. Pollutants that become 

trapped in the snowpack are also expected to be concentrated in areas of heavy OSV use. Therefore, 

in this analysis, areas within a half mile of designated OSV trails (groomed or not) are assumed to be 

reasonably at risk from the effects of OSV pollutants. Outside the designated OSV trail corridors, 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

291

dispersed OSV travel is much less likely to contribute harmful contaminants with high enough levels

and repetition to measurably or predictably affect ground vegetation, and therefore is not considered 

in this analysis as an expected source of indirect effects.

Relative Potential Effects to Plant Life Forms

Considering the combination of direct and indirect effects described above, and the requirement of 

adequate snow to avoid resource damage or minimum snow depths of the alternatives, the effects of 

proposed OSV uses can be broken down into relative categories of potential damage to the major 

plant life forms. From the most likely to least likely to experience measurable effects:

• Evergreen trees and shrubs – most likely to be directly affected, due to mechanical damage; 

indirect effects are expected if the species occurs near designated OSV trails. Effects may occur 

in all areas designated for OSV use.

• Deciduous trees and shrubs – somewhat less likely, due to winter dormancy; indirect effects are

expected if the species occurs near designated OSV trails. Effects may occur in all areas 

designated for OSV use.

• Sub-shrubs (low-growing woody species) – less likely due to less exposure to direct effects (but 

still expected); indirect effects may be expected if the species occurs near designated OSV trails.

Effects may occur in all areas designated for OSV use.

• Perennial herbaceous species – direct effects are not expected to occur due to the requirement of 

adequate snow to avoid resource damage or minimum snow depths; indirect effects may be 

expected if the species occurs near designated OSV trails. Effects may occur along designated 

OSV trails, but are not likely in areas designated for OSV use.

• Annual species – direct effects are highly unlikely due to the requirement of adequate snow to 

avoid resource damage or minimum snow depths; indirect effects might be expected if the 

species occurs near designated OSV trails and spring flowering could be altered by persistent 

compacted snow. Effects may occur along designated OSV trails, but are not likely in areas 

designated for OSV use.

• Aquatic species – direct effects would not occur because OSV use is not allowed over open 

water; indirect effects from pollutants might be expected if the species occurs near designated 

OSV trails. Effects may occur along designated OSV trails, but are not likely in areas designated 

for OSV use.

Threatened and Endangered Plants

Packera layneae (Layne’s butterweed)

Direct Effects

Layne’s butterweed is an herbaceous perennial that dies back to the ground each year. Because of the 

plant’s dormancy during the winter OSV use period and the requirement of adequate snow to avoid 

resource damage or minimum snow depths preventing OSV contact with soil and ground vegetation, 

Layne’s butterweed would not be directly affected by OSV use or snow trail grooming activities.

The two occurrences on the Tahoe National Forest are present in an area that is designated for OSV 

use only in alternatives 1 and 4, and public OSV use would only occur only when these areas 

accumulate adequate snow and soil and vegetation resources would likely be protected from damage. 
Over-snow Vehicle Use Designation

Tahoe National Forest

292

Indirect Effects

The Layne’s butterweed occurrences do not exist in high-use areas, where snow compaction and 

pollutants would be concentrated. There would be no indirect effects to Layne’s butterweed because 

dispersed OSV use as described for all alternatives would not likely cause any noticeable changes 

from compaction of snow or pollutants. In alternatives 1 and 4, the area where Layne’s butterweed is 

located would be open to dispersed OSV use, whereas in alternatives 2, 3, and 5, this area is not 

designated for public OSV use. 

Trees, shrubs, or sub-shrub species

Direct Effects

Snowmobile activities may damage vegetation on and along trails and in areas open to cross-country

OSV use. The most commonly observed effect from snowmobiles has been the physical damage to 

shrubs, saplings, and other vegetation (Neumann and Merriam 1972, Wanek 1971). Winter Wildland 

Alliance (WWA) analyzed the Gallatin National Forest regeneration survey data collected between 

1983 and 1996 in areas that were harvested and replanted. That survey data indicated snowmobiles 

had damaged between 12 and 720 trees per acre (WWA 2009). Damage to vegetation has been 

observed in the Greater Yellowstone Area that is caused by winter recreational activities that occur 

off trail. For example, branches of willows (Salix spp.) and sagebrush (Artemisia spp.) have been 

broken, and leaders have been removed from conifers (Stangl 1999). Neumann and Merriam (1972) 

found that rigid woody stems up to 1 inch in diameter were very susceptible to damage. Stems were 

snapped off in surface packed or crusted snow. Neumann and Merriam (1972) also observed that 

compacted snow conditions caused twigs and branches to bend sharply and break. Stems that were 

more pliable bent and sprang back although the snowmobile track often removed bark from the 

stems’ upper surfaces. Sub-zero temperatures make stems more prone to snapping rather than 

bending. Direct mechanical effects by snowmobiles on vegetation at and above snow surface can be 

severe. After only a single pass by a snowmobile, more than 78 percent of the saplings on a trail were 

damaged, and nearly 27 percent of them were damaged seriously enough to cause a high probability 

of death (Neumann and Merriam 1972). Young conifers were found to be extremely susceptible to 

damage from snowmobiles. Broken stems of any woody species would provide places for pathogens 

to enter the plant tissues and would reduce the integrity of developing stems or trunks, both of which 

could lead to additional damage or death of individuals.

Direct damage to woody plants may occur with OSV use on any snow depth. When OSVs are 

operated on low snow depths, shorter woody plants (including sub-shrubs, shrubs, and young trees) 

are more prone to damage because their living stems are present in the snow column that could be 

churned by OSV tracks and paddles or disrupted by OSV skis as they are ridden across the 

landscape. During the middle portion of the OSV season, snowpack is typically several feet deep and 

the shorter woody plants would not be directly affected. There would still be considerable possibility 

for damage to taller shrubs and tree species (most notably Pinus albicaulis, whitebark pine) with 

deeper snowpack, with potential for unintentional breakage and abrasion of branches and leader 

growth. These direct effects are expected to be localized, would affect only individuals due to the 

dispersed nature of open area OSV use, and would not result in loss of entire occurrences.

On the Tahoe National Forest, OSV use may directly damage individuals of the Region 5 sensitive 

species Eriogonum umbellatum var. torreyanum and Pinus albicaulis, due to their presence in areas 

designated for OSV use.

For Pinus albicaulis, because many occurrences are not yet tracked spatially, it is worth mentioning 

that over 13,000 acres of subalpine conifer forest on the Tahoe National Forest likely provide 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

293

considerably more suitable habitat and additional occurrences beyond the few acres specifically 

mapped as a special status species. Each of the alternatives proposes to allow OSV use on 

approximately 2,300 to 5,200 of these acres. Additional habitat is also present but not mapped or 

tallied for the other sensitive plant species.

Indirect Effects

Airborne pollutants from OSVs would be concentrated along OSV trails. Because deciduous trees 

and shrubs lose their leaves in the winter months, they cannot photosynthesize during fall and winter; 

thus respiration is dramatically reduced for deciduous trees and shrubs. Although evergreen trees and 

shrubs retain their leaves and are thus capable of photosynthesis and respiration during winter, these 

processes are also considerably reduced during the cold season. Reduced respiration during the 

winter means that smaller amounts of the airborne pollutants would be ingested through gas 

exchange. For low-growing woody species that are generally covered by snow when OSV use would 

occur (Eriogonum umbellatum var. torreyanum), the exposure to airborne pollutants would be 

negligible.

Pollutants which are trapped and then released during snowmelt may (or may not) have some 

adverse and some beneficial effects, however the extent and direction of specific effects is unknown. 

It is expected that pollutant concentrations would be low enough that water quality would not be 

impaired, and thus it is likely that plant responses, if any, would not be noticeable.

Perennial herbaceous species (including bryophytes and fungi)

Direct Effects

With the requirement of adequate snow to avoid resource damage or minimum snow depths 

providing protection of the soil surface and ground vegetation, perennial herbaceous species (which 

die back each year to buds at or below the soil surface) would not be directly affected by current or 

proposed OSV uses.

Indirect Effects

Snow compaction from dispersed OSV use is not expected to affect perennial herbaceous species 

because the possible delayed snowmelt (usually a week or two) and small degree of colder soil 

temperatures in the compacted snow areas would be within the normal range of variation that they 

experience on the Tahoe National Forest. Where it occurs each year, compacted snow may alter the 

timing of new foliage emergence in the spring due to delayed snowmelt and colder soil temperatures, 

but perennial herbaceous plants in the Sierra Nevada are assumed to be adapted to a wide variety of 

natural snowmelt times and the effects of compacted snow would likely be masked by the annual 

variation in snowpack. 

Pollutants from dispersed OSV use (both airborne and those small amounts that become entrapped in 

the snow) would also not likely affect perennial herbaceous species because living plant tissues are 

not present above ground during the winter and pollutants are not expected to accumulate within the 

snow column or in run-off at high enough concentrations to cause noticeable changes.

Where occurrences exist in high-use areas, compaction and pollutants may be concentrated enough 

to cause some small magnitude changes to plant growth and community interactions. No populations 

are expected to decline with any of the proposed OSV uses.
Over-snow Vehicle Use Designation

Tahoe National Forest

294

Annual plant species

Direct Effects

Plant species that complete their life cycle within one growing season would not be directly affected 

by current or proposed OSV uses because they are normally not growing during the authorized 

period of OSV use.

Indirect Effects

Snow compaction from dispersed OSV use is not expected to affect annual species because the 

possible delayed snowmelt (usually a week or two) and small degree of colder soil temperatures in 

the compacted snow areas would be within the normal range of variation. Compacted snow may 

slightly alter the timing of seed germination and plant growth in the spring, due to delayed snowmelt 

and colder soil temperatures in the compacted areas. This is not expected to noticeably affect annual 

plants because they are assumed to be adapted to a wide variety of natural snowmelt times within 

their ranges of distribution. The annual variation in snowpack and temperatures would likely mask 

any differences in phenology due to OSV uses.

Pollutants from dispersed OSV use (both airborne and those small amounts that become entrapped in 

the snow) would also not likely affect annual species because living plant tissues are not present 

above ground during the winter and pollutants are not expected to accumulate within the snow 

column or in run-off at high enough concentrations to cause any noticeable changes.

Where occurrences exist in high-use areas, compaction and pollutants may be concentrated enough 

to cause some small magnitude changes to plant community interactions. Phacelia stebbinsii is the 

only annual sensitive plant species on the Tahoe National Forest. Some occupied areas are within 

high-use areas, but no populations are expected to decline with any of the proposed OSV uses.

Aquatic Species

Direct Effects

Aquatic plant species would not be directly affected by current or proposed OSV uses, because 

OSVs are not authorized to operate over or within aquatic habitats.

Indirect Effects

Delayed snowmelt and transfer of sub-freezing temperatures from snow compaction is not expected 

to affect aquatic plant species. 

Airborne pollutants would not affect aquatic species because the plants grow underwater. In 

dispersed open areas, pollutants are not expected to accumulate within the snow column or in run-off 

at high enough concentrations to cause any noticeable changes to vegetation. 

Peltigera gowardii is the only aquatic sensitive plant species suspected, but it has not yet been found 

on the Tahoe National Forest, and thus would not be affected.

Cumulative Effects

Past activities are considered part of the existing condition and are discussed within the Affected 

Environment section. 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. By looking at current conditions, we are sure to capture all the residual effects of 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

295

past human actions and natural events, regardless of which particular action or event contributed to 

those effects. Sensitive plant occurrences that exist today on the Tahoe National Forest are the result 

of these species’ interactions with past environmental conditions and natural and human 

disturbances. In terms of sensitive plant habitats, past actions have resulted in an increase in densely 

forested stands, an increase in decadent shrubs, a decrease in key early-seral habitat components 

such as aspen stands, meadows, grasses and forbs, and young brush fields, and changed historic flow 

regimes in meadows/riparian habitats.

Snow plowing at the established OSV trailheads is an ancillary activity associated with the Tahoe

National Forest OSV Use Designation project, and is not analyzed as a part of the proposal. Snow 

plowing is not expected to affect TEPS plants. 

Other ongoing and foreseeable future activities include livestock grazing, recreation, timber harvest, 

fuel reduction, woodcutting activities, wildfire suppression, and other activities. These activities may 

affect some sensitive plants individually, but no trends toward Federal listing or loss of species 

viability are expected due to protective measures deemed necessary during environmental analysis 

and implemented as required. Impacts related to hikers and OHV activities (trampling, soil 

disturbance, dust accumulation on plants, etc.) are ongoing and are expected to increase as the 

numbers of national forest visitors rise. Timber harvest, fuel reduction, fire suppression, emergency 

responses, and other actions carried out by Federal workers or contractors are typically able to 

provide adequate protection for sensitive plant occurrences using flag and avoid methods or other 

specific measures designed for species protection. See appendix C for details on specific activities.

Threatened and Endangered Plants

Ongoing activities and natural growth and succession would contribute to some changes to Packera 

layneae habitat as they have in the past. Future actions are also not expected to adversely affect this 

species because avoidance measures would be incorporated into the planning and implementation of 

the projects. Since there would be no direct or indirect effects to Packera layneae or their associated 

critical habitat, there are no cumulative effects to consider for this species.

Sensitive Plants

It is expected that all current and future projects include mitigations, such as avoidance measures or 

other project design features to minimize adverse impacts to Region 5 sensitive plant species.

These sensitive plants are currently experiencing the everyday stresses of life in the wild, with 

drought likely impacting their growth and seed production in recent years. Besides the threat of 

physical damage from many of the contributing actions, these species are also threatened by invasive 

plant encroachments. Continuing pressures on sensitive plant habitats include wildfire, early or late 

freezing, severe wind or winter storms, flooding, insect population fluxes, and other natural events. 

These events may also cause damage or death to sensitive plant individuals or cause habitat changes.

Effects may include damage to or death of individuals, through project actions and possible effects 

from introduced invasive species, increased soil erosion, and other changes to habitat characteristics. 

It is expected that all of these projects would include reasonable mitigations to minimize or reduce 

impacts and monitor for concerns to help manage impacts to sensitive plant species habitat and 

occurrences. Through project design features, the potential for these impacts to occur is small. If 

impacts still occur, only low intensity, localized effects are expected for the sensitive plant species. 
Over-snow Vehicle Use Designation

Tahoe National Forest

296

The annual, seasonal timing of OSV effects does not eliminate the chance of direct and indirect 

effects accumulating. Broken branches of woody plants and any deceased individual plants would 

require one to several years to recover, and additional actions would be taking place during this 

recovery time.

Individually and collectively, the magnitude of effects from these actions would remain relatively 

low. Natural disturbances, such as fire, wind and ice storms, and drought are much more likely to 

impact sensitive plant species, and their effects would be considerably greater. With cumulative 

effects considered, sensitive plant species viability in the OSV project area would be maintained and 

no trend toward Federal listing would occur. When effects from other projects are combined and if 

they overlap with the effects from the Tahoe OSV Use project, there would still be no loss of 

viability for any plant species and none would trend toward Federal listing, for all alternatives. 

Alternative 1 – No Action

Alternative 1 Effects to TEPS plants

The following table summarizes the measures by the major analysis topics.

Table 96. TEPS plant indicators and measures for alternative 1

Analysis Topic Total acres on Tahoe 

National Forest

Acres in high-use

areas

Acres in designated 

OSV areas

Threatened and 

Endangered plants 57 0 57

Sensitive plants 2,496 308 2,051

There are no additional types of effects to TEPS plants beyond those described in Effects Common 

to All Alternatives that are specific to alternative 1. Under this alternative, direct effects to these 

botanical resources would be more likely due to larger areas open to OSV use.

Alternative 1 has no minimum snow depth requirement for OSV use, but riders still must not damage 

the underlying soil and vegetation resources because causing resource damage is illegal. It is 

assumed that a minimum of 12 inches of snow is typically needed to avoid damaging resources, and 

on trails with underlying roads, a minimum of 6 inches is typically needed to avoid damage to the 

underlying road surface. These are essentially the same requirements for snow depth as alternative 2, 

and would provide a reasonable protection for non-woody TEPS and special interest plants. 

Threatened and Endangered Plants

As described above in Effects Common to All Alternatives, there would be no direct effects to 

Packera layneae.

Sensitive Plants

Sensitive plant species in the various plant life form categories would be affected differently, as 

described above in Effects Common to All Alternatives. Trees, shrubs, and sub-shrubs (woody 

plants) may be directly damaged by OSVs where they occur in areas designated for OSV use, and 

they may also experience indirect effects from snow compaction and pollutants, most likely to be 

noticeable where they occur near designated OSV trails. Perennial herbaceous species, annual 

species and aquatic species would not be directly affected, but they too may also experience 

noticeable indirect effects if they occur near designated OSV trails.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

297

Indirect effects from snow compaction are expected to be greater with alternatives 1, 2, and 4 

because only a minimal protection is afforded to ground vegetation. Alternative 1 also provides a 

minimal protection for woody sensitive plants because, although a minimum snow depth is not 

identified, enforcement of a reasonable avoidance of resource damage is the management tool used 

to keep OSV use from occurring when snow depths are too low. 

Sensitive Plant Determinations for Alternative 1:

For two of the three sensitive woody plant species, Eriogonum umbellatum var. torreyanum and 

Pinus albicaulis, due to the possibility of direct damage to individuals and minor indirect effects 

from snow compaction and OSV pollutants where they occur in areas designated for OSV use, 

alternative 1 of the Tahoe OSV Use Designation project may affect individuals, but is not likely to 

result in a trend toward Federal listing or loss of viability in the planning area. The third sensitive 

woody plant species considered, Monardella follettii, is not known to occur on the Tahoe National 

Forest, and would not be affected.

After evaluating the specific habitat requirements of each species and likely interactions with OSV 

use, minor indirect effects from snow compaction and OSV pollutants would be possible for any of 

the sensitive plant species present in areas of high OSV use. Therefore, alternative 1 of the Tahoe 

OSV Use Designation project may affect individuals, but is not likely to result in a trend toward 

Federal listing or loss of viability in the planning area for Botrychium crenulatum, Botrychium

minganense, Bruchia bolanderi, Erigeron miser, Ivesia sericoleuca, Lewisia kelloggii ssp. 

hutchisonii, Meesia uliginosa, Phacelia stebbinsii, and Poa sierrae.

Because the following species are not known to exist in areas of high OSV use, alternative 1 of the 

Tahoe OSV Use Designation project would have no effect on Botrychium ascendens, Cypripedium 

fasciculatum, Fritillaria eastwoodiae, Ivesia aperta var. aperta, Lewisia cantelovii, Lewisia kelloggii

ssp. kelloggii, Lewisia longipetala, Lewisia serrata, Peltigera gowardii, Penstemon personatus,

Phaeocollybia olivaceae, Pyrrocoma lucida, and Tauschia howellii.

Because the following species are not known to exist at all on the Tahoe National Forest, alternative 

1 of the Tahoe OSV Use Designation project would have no effect on Astragalus lemmonii, 

Astragalus pulsiferae var. coronensis, Astragalus webberi, Boechera rigidissima, Botrychium 

lunaria, Botrychium montanum, Cudonia monticola, Cypripedium montanum, Dendrocollybia 

racemosa, Helodium blandowii, Ivesia aperta var. canina, Juncus luciensis, Mielichhoferia elongata, 

Monardella follettii, Peltigera gowardii, and Sowerbyella rhenana.

Alternative 2 – Modified Proposed Action

Alternative 2 Effects to TEPS Plants

The following table summarizes these measures by the major analysis topics.

Table 97. TEPS plant indicators and measures for alternative 2

Analysis Topic Total acres on Tahoe 

National Forest

Acres in highuse areasAcres in designated 

OSV areas

Threatened and Endangered plants 57 0 0

Sensitive plants 2,496 253 1,294
Over-snow Vehicle Use Designation

Tahoe National Forest

298

No additional types of effects to TEPS plants and other botanical resources beyond those described 

in Effects Common to All Alternatives are specific to alternative 2. 

In comparison with other alternatives, alternative 2 would be relatively equal with alternatives 1 and 

4 in providing the minimum snow depth needed to prevent damage to resources (assumed to be 

12 inches). In contrast, alternatives 3 and 5 would increase minimum snow depths to 18 inches and 

24 inches, respectively, and would provide additional degrees of protection and assurance that soil 

and vegetation resources are not damaged.

Threatened and Endangered Plants

As described above in Effects Common to All Alternatives, there would be no direct effects to 

Packera layneae. The two occurrences on Tahoe National Forest are not near any OSV trail. Indirect 

effects are not likely to occur from the small amounts of snow compaction and pollutants associated 

with dispersed OSV use. Because no direct, indirect, or cumulative effects to this species are 

expected, alternative 2 of the Tahoe OSV Use Designation project would have no effect on Packera 

layneae.

Sensitive Plants

Sensitive plant species in the various plant life form categories would be affected differently, as 

described above in Effects Common to All Alternatives. Trees, shrubs, and sub-shrubs (woody 

plants) may be directly damaged by OSVs where they occur in areas designated for OSV use, and 

they may also experience indirect effects where they occur near designated OSV trails. Perennial 

herbaceous species, annual species and aquatic species would not be directly affected, but they may 

also experience indirect effects if they occur near designated OSV trails.

With alternative 2, a 12-inch minimum snow depth is expected to prevent direct effects to nonwoody sensitive plants. 

Indirect effects from snow compaction are expected to be greater with alternatives 1, 2, and 4 

because 12 inches is considered a minimal protection afforded to ground vegetation. Alternative 2 

provides a minimal protection for non-woody sensitive plants because cross-country travel is 

allowed when there is adequate snow depth to avoid damage to (soil and ground vegetation) 

resources. However, there could still be considerable direct damage to woody species throughout the 

OSV season, with possible unintentional breakage and abrasion of branches and leader growth.

Because the amount of area designated for OSV use is relatively moderate at 406,895 acres, 

alternative 2 would have less impacts to sensitive plant occurrences than alternatives 1 and 4, but 

more than alternatives 3 and 5.

Sensitive Plant Determinations for Alternative 2:

For two of the three sensitive woody plant species, Eriogonum umbellatum var. torreyanum and 

Pinus albicaulis, due to the possibility of direct damage to individuals and minor indirect effects 

from snow compaction and OSV pollutants where they occur in areas designated for OSV use, 

alternative 2 of the Tahoe OSV Use Designation project may affect individuals, but is not likely to 

result in a trend toward Federal listing or loss of viability in the planning area.

After evaluating the specific habitat requirements of each species and potential interactions with 

OSV use, minor indirect effects from snow compaction and OSV pollutants would be possible for 

any of the sensitive plant species present in areas of high OSV use. Therefore, alternative 2 of the 

Tahoe OSV Use Designation project may affect individuals, but is not likely to result in a trend 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

299

toward Federal listing or loss of viability in the planning area for Botrychium crenulatum, 

Botrychium minganense, Bruchia bolanderi, Erigeron miser, Ivesia sericoleuca, Lewisia kelloggii

ssp. hutchisonii, Lewisia serrata, Phacelia stebbinsii, and Poa sierrae.

Because the following species are not known to exist in areas of high OSV use, alternative 2 of the 

Tahoe OSV Use Designation project would have no effect on Botrychium ascendens, Cypripedium 

fasciculatum, Fritillaria eastwoodiae, Ivesia aperta var. aperta, Lewisia cantelovii, Lewisia kelloggii

ssp. kelloggii, Lewisia longipetala, Meesia uliginosa, Peltigera gowardii, Penstemon personatus,

Phaeocollybia olivaceae, Pyrrocoma lucida, and Tauschia howellii.

Because the following species are not known to exist at all on the Tahoe National Forest, alternative 

2 of the Tahoe National Forest OSV Designation Use project would have no effect on Astragalus 

lemmonii, Astragalus pulsiferae var. coronensis, Astragalus webberi, Boechera rigidissima,

Botrychium lunaria, Botrychium montanum, Cudonia monticola, Cypripedium montanum, 

Dendrocollybia racemosa, Helodium blandowii, Ivesia aperta var. canina, Juncus luciensis,

Mielichhoferia elongata, Monardella follettii, Peltigera gowardii, and Sowerbyella rhenana.

Alternative 3

Alternative 3 Effects to TEPS Plants

The following table summarizes these same measures by the major analysis topics.

Table 98. TEPS plant indicators and measures for alternative 3

Analysis Topic Total acres on Tahoe 

National Forest

Acres in highuse areasAcres in designated 

OSV areas

Threatened and Endangered plants 57 0 0

Sensitive plants 2,496 102 902

No additional types of effects to TEPS plants and other botanical resources beyond those described 

in Effects Common to All Alternatives are specific to alternative 3.

In comparison with alternatives 1, 2, and 4, because of its 18-inch minimum snow depth, alternative 

3 would provide a low to moderate degree of additional protection and assurance that soil and 

vegetation resources are not damaged. However, alternative 5 would increase minimum snow depths 

to 24 inches and would provide further protection of resources.

Threatened and Endangered Plants

As described above in Effects Common to All Alternatives, there would be no direct effects to 

Packera layneae. The two occurrences on Tahoe National Forest are not near any OSV trail. Indirect 

effects are not likely to occur from the small amounts of snow compaction and pollutants associated 

with dispersed OSV use. Because no direct, indirect, or cumulative effects to this species are 

expected, alternative 3 of the Tahoe OSV Use Designation project would have no effect on Packera 

layneae.
Over-snow Vehicle Use Designation

Tahoe National Forest

300

Sensitive Plants

Sensitive plant species in the various plant life form categories would be affected differently, as 

described above in Effects Common to All Alternatives. Trees, shrubs, and sub-shrubs (woody 

plants) may be directly damaged by OSVs where they occur in areas designated for OSV use, and 

they may also experience indirect effects where they occur near designated OSV trails. Perennial 

herbaceous species, annual species and aquatic species would not be directly affected, but they also 

may experience indirect effects if they occur near designated OSV trails.

In comparison with alternatives 1, 2, and 4, increasing minimum snow depths to 18 inches for crosscountry travel would add an extra measure of protection for TEPS plants and their habitats, but 

effects already described would still be possible.

Alternative 3 provides a moderate level of protection for all sensitive plants because an additional 

6 inches of snow is required for OSV use, providing a deeper cushion to absorb snow compaction 

and further protection from direct effects to the shortest woody plant species. Non-woody sensitive 

plants are not expected to be directly affected. However, there could still be damage to woody 

species throughout the OSV season, with possible unintentional breakage and abrasion of branches 

and leader growth. 

Because alternative 3 would allow cross-country OSV travel in the least area (275,972 acres), it 

would impact the fewest sensitive plant occurrences.

Sensitive Plant Determinations for Alternative 3:

For two of the three sensitive woody plant species, Eriogonum umbellatum var. torreyanum and 

Pinus albicaulis, due to possible direct damage to individuals and minor indirect effects from snow 

compaction and OSV pollutants where they occur in areas designated for OSV use, alternative 3 of 

the Tahoe OSV Use Designation project may affect individuals, but is not likely to result in a 

trend toward Federal listing or loss of viability in the planning area.

After evaluating the specific habitat requirements of each species and potential interactions with 

OSV use, minor indirect effects from snow compaction and OSV pollutants would be possible for 

any of the sensitive plant species present in areas of high OSV use. Therefore, alternative 3 of the 

Tahoe OSV Use Designation project may affect individuals, but is not likely to result in a trend 

toward Federal listing or loss of viability in the planning area for Botrychium crenulatum, 

Botrychium minganense, Bruchia bolanderi, Erigeron miser, Ivesia sericoleuca, Lewisia kelloggii

ssp. hutchisonii, Meesia uliginosa, Phacelia stebbinsii, and Poa sierrae.

Because the following species are not known to exist in areas of high OSV use, alternative 3 of the 

Tahoe OSV Use Designation project would have no effect on Botrychium ascendens, Cypripedium 

fasciculatum, Fritillaria eastwoodiae, Ivesia aperta var. aperta, Lewisia cantelovii, Lewisia kelloggii

ssp. kelloggii, Lewisia longipetala, Lewisia serrata, Peltigera gowardii, Penstemon personatus,

Phaeocollybia olivaceae, Pyrrocoma lucida, and Tauschia howellii.

Because the following species are not known to exist at all on the Tahoe National Forest, alternative 

3 of the Tahoe OSV Use Designation project would have no effect on Astragalus lemmonii, 

Astragalus pulsiferae var. coronensis, Astragalus webberi, Boechera rigidissima, Botrychium 

lunaria, Botrychium montanum, Cudonia monticola, Cypripedium montanum, Dendrocollybia 

racemosa, Helodium blandowii, Ivesia aperta var. canina, Juncus luciensis, Mielichhoferia elongata, 

Monardella follettii, Peltigera gowardii, and Sowerbyella rhenana.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

301

Alternative 4

Alternative 4 Effects to TEPS Plants

The following table summarizes the measures by the major analysis topics.

Table 99. TEPS plant indicators and measures for alternative 4

Analysis Topic Total acres on Tahoe 

National Forest

Acres in highuse areas

Acres in 

designated OSV 

areas

Threatened and endangered plants 57 0 57

Sensitive plants 2,496 354 2,062

No additional types of effects to TEPS plants and other botanical resources beyond those described 

in Effects Common to All Alternatives are specific to alternative 4. 

With a 12-inch minimum snow depth, alternative 4 is similar to alternatives 1 and 2, providing the 

minimum snow depth needed to prevent damage to resources (assumed to be 12 inches). However, 

alternatives 3 and 5 would increase minimum snow depths to 18 inches and 24 inches, respectively, 

and would provide additional degrees of protection and assurance that soil and vegetation resources 

are not damaged.

Threatened and Endangered Plants

As described above in Effects Common to All Alternatives, there would be no direct effects to 

Packera layneae. The two occurrences on Tahoe National Forest are not near any OSV trail. Indirect 

effects are not likely to occur from the small amounts of snow compaction and pollutants associated 

with dispersed OSV use. Because no direct, indirect, or cumulative effects to this species are 

expected, alternative 4 of the Tahoe OSV Use Designation project would have no effect on Packera 

layneae.

Sensitive Plants

Sensitive plant species in the various plant life form categories would be affected differently, as 

described above in Effects Common to All Alternatives. Trees, shrubs, and sub-shrubs (woody 

plants) may be directly damaged by OSVs where they occur in areas designated for OSV use, and 

they may also experience indirect effects where they occur near designated OSV trails. Perennial 

herbaceous species, annual species and aquatic species would not be directly affected, but they too 

may also experience indirect effects if they occur near designated OSV trails.

Alternative 4 requires a minimum of 12 inches of snow for cross-country OSV use. This is 

considered to be a minimum reasonable protection for soil and ground vegetation. A 12-inch 

minimum snow depth is expected to prevent direct effects to non-woody sensitive plants.

Indirect effects from snow compaction are expected to be greater with alternatives 1, 2, and 4 

because only a minimal protection is afforded to ground vegetation. Alternative 4 provides minimal 

protection for woody sensitive plants because cross-country travel is allowed when there is just 

adequate snow depth to avoid damage to (soil and ground vegetation) resources, but there could still 

be damage to woody species throughout the OSV season, with unintentional breakage and abrasion 

of branches and leader growth.
Over-snow Vehicle Use Designation

Tahoe National Forest

302

Because alternative 4 would allow cross-country OSV use on the greatest area (641,105 acres), it 

would have the potential to impact the most area of sensitive plant occurrences.

Sensitive Plant Determinations for Alternative 4:

For two of the three sensitive woody plant species, Eriogonum umbellatum var. torreyanum and 

Pinus albicaulis, due to possible direct damage to individuals and minor indirect effects from snow 

compaction and OSV pollutants where they occur in areas designated for OSV use, alternative 4 of 

the Tahoe OSV Use Designation project may affect individuals, but is not likely to result in a 

trend toward Federal listing or loss of viability in the planning area.

After evaluating the specific habitat requirements of each species and potential interactions with 

OSV use, minor indirect effects from snow compaction and OSV pollutants would be possible for 

any of the sensitive plant species present in areas of high OSV use. Therefore, alternative 4 of the 

Tahoe OSV Use Designation project may affect individuals, but is not likely to result in a trend 

toward Federal listing or loss of viability in the planning area for Botrychium crenulatum, 

Botrychium minganense, Bruchia bolanderi, Erigeron miser, Ivesia sericoleuca, Lewisia kelloggii

ssp. hutchisonii, Meesia uliginosa, Phacelia stebbinsii, and Poa sierrae.

Because the following species are not known to exist in areas of high OSV use, alternative 4 of the 

Tahoe OSV Use Designation project would have no effect on Botrychium ascendens, Cypripedium 

fasciculatum, Fritillaria eastwoodiae, Ivesia aperta var. aperta, Lewisia cantelovii, Lewisia kelloggii

ssp. kelloggii, Lewisia longipetala, Lewisia serrata, Peltigera gowardii, Penstemon personatus,

Phaeocollybia olivaceae, Pyrrocoma lucida, and Tauschia howellii.

Because the following species are not known to exist at all on the Tahoe National Forest, alternative 

4 of the Tahoe OSV Use Designation project would have no effect on Astragalus lemmonii, 

Astragalus pulsiferae var. coronensis, Astragalus webberi, Boechera rigidissima, Botrychium 

lunaria, Botrychium montanum, Cudonia monticola, Cypripedium montanum, Dendrocollybia 

racemosa, Helodium blandowii, Ivesia aperta var. canina, Juncus luciensis, Mielichhoferia elongata, 

Monardella follettii, Peltigera gowardii, and Sowerbyella rhenana..

Alternative 5

Alternative 5 Effects to TEPS Plants

The following table summarizes the measures by the major analysis topics.

Table 100. TEPS plant indicators and measures for alternative 5

Analysis Topic Total acres on Tahoe 

National Forest

Acres in highuse areasAcres in designated 

OSV areas

Threatened and endangered plants 57 0 0

Sensitive plants 2,496 237 986

No additional types of effects to TEPS plants and other botanical species beyond those described in 

Effects Common to All Alternatives are specific to alternative 5. Increasing the minimum snow depth 

requirement to 24 inches would add a moderate extra measure of protection for TEPS plants and 

their habitats, but effects already described would still be possible.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

303

Threatened and Endangered Plants

As described above in Effects Common to All Alternatives, there would be no direct effects to 

Packera layneae. The two occurrences on Tahoe National Forest are not near any OSV trail. Indirect 

effects are not likely to occur from the small amounts of snow compaction and pollutants associated 

with dispersed OSV use. Because no direct, indirect, or cumulative effects to this species are 

expected, alternative 5 of the Tahoe OSV Use Designation project would have no effect on Packera 

layneae.

Sensitive Plants

Sensitive plant species in the various plant life form categories would be affected differently, as 

described above in Effects Common to All Alternatives. Trees, shrubs, and sub-shrubs (woody 

plants) may be directly damaged by OSVs where they occur in areas designated for OSV use, and 

they may also experience indirect effects where they occur near designated OSV trails. Perennial 

herbaceous species, annual species and aquatic species would not be directly affected, but they too 

may also experience indirect effects if they occur near designated OSV trails.

Alternative 5 provides the highest level of protection for sensitive plants in areas designated for OSV 

use because an additional 12 inches of snow is required, providing a deeper cushion to absorb snow 

compaction and further protection from direct effects to the shorter woody plant species. Non-woody 

sensitive plants are not expected to be directly affected. However, there could still be considerable 

damage to woody species throughout the OSV season, with unintentional breakage and abrasion of 

branches and leader growth. 

Because there would be a smaller area open to cross-country OSV use (300,146 acres), alternative 5 

would have a smaller potential for impacts to sensitive plant occurrences than other alternatives, 

except alternative 3.

Sensitive Plant Determinations for Alternative 5:

For two of the three sensitive woody plant species, Eriogonum umbellatum var. torreyanum and 

Pinus albicaulis, due to the possibility of direct damage to individuals and minor indirect effects 

from snow compaction and OSV pollutants where they occur in areas designated for OSV use, 

alternative 5 of the Tahoe OSV Use Designation project may affect individuals, but is not likely to 

result in a trend toward Federal listing or loss of viability in the planning area.

After evaluating the specific habitat requirements of each species and potential interactions with 

OSV use, minor indirect effects from snow compaction and OSV pollutants would be possible for 

any of the sensitive plant species present in areas of high OSV use. Therefore, alternative 5 of the 

Tahoe OSV Use Designation project may affect individuals, but is not likely to result in a trend 

toward Federal listing or loss of viability in the planning area for Botrychium crenulatum, 

Botrychium minganense, Bruchia bolanderi, Erigeron miser, Ivesia sericoleuca, Lewisia kelloggii

ssp. hutchisonii, Phacelia stebbinsii, and Poa sierrae.

Because the following species are not known to exist in areas of high OSV use, alternative 5 of the 

Tahoe OSV Use Designation project would have no effect on Botrychium ascendens, Cypripedium 

fasciculatum, Fritillaria eastwoodiae, Ivesia aperta var. aperta, Lewisia cantelovii, Lewisia kelloggii

ssp. kelloggii, Lewisia longipetala, Lewisia serrata, Meesia uliginosa, Peltigera gowardii,

Penstemon personatus, Phaeocollybia olivaceae, Pyrrocoma lucida, and Tauschia howellii.
Over-snow Vehicle Use Designation

Tahoe National Forest

304

Because the following species are not known to exist at all on the Tahoe National Forest, alternative 

5 of the Tahoe OSV Use Designation project would have no effect on Astragalus lemmonii, 

Astragalus pulsiferae var. coronensis, Astragalus webberi, Boechera rigidissima, Botrychium 

lunaria, Botrychium montanum, Cudonia monticola, Cypripedium montanum, Dendrocollybia 

racemosa, Helodium blandowii, Ivesia aperta var. canina, Juncus luciensis, Mielichhoferia elongata, 

Monardella follettii, Peltigera gowardii, and Sowerbyella rhenana.

Summary of TEPS Plant Effects

Summary of TEPS Plant Measures and Determinations

Table 101. TEPS plant summary of measures for all alternatives

Analysis Topic Total acres on Tahoe 

National Forest

Acres in high-use

areas

Acres in 

designated OSV 

areas

Threatened and endangered plants

57 0 all alternatives

57 Alt.1

0 Alt. 2

0 Alt. 3

57 Alt. 4

0 Alt. 5

Sensitive plants 

2,496

308 Alt. 1

253 Alt. 2

102 Alt. 3

354 Alt. 4

237 Alt. 5

2,051 Alt. 1

1,294 Alt. 2

902 Alt. 3

2,062 Alt. 4

986 Alt. 5

Threatened and Endangered Plants

There would be no direct effects to Packera layneae from the proposed OSV uses. The two 

occurrences on Tahoe National Forest are not within 0.5 mile of any OSV trail, in any alternative, 

and thus, are not in the assumed high-use areas. Indirect effects from snow compaction and 

pollutants associated with dispersed OSV use are not expected to affect this perennial herbaceous 

species.

Therefore, for all alternatives, there would be no effect to Packera layneae from the Tahoe OSV Use 

Designation project. 

Sensitive Plants

Sensitive woody plant species may be directly affected by crushing, breaking, or abrasion of stems 

and evergreen foliage where they occur in any areas designated for OSV use. Plants of other life 

form categories would not be directly affected because their living tissues are not present above 

ground, and would not be directly damaged by OSVs. Any of the sensitive plants may be indirectly 

affected by snow compaction and/or OSV emissions containing pollutants where they occur in areas 

of high-use (open areas within 0.5 mile of designated OSV trails). Thus, these plant species are 

reasonably at risk to some level of effects, dependent on their life forms, timing of growth, and 

proximity to heavy OSV use. Indirect effects are expected to be minor, and all effects would be 

minimized by the required minimum snow depths or conditional requirements proposed. Although 

some individuals may be severely damaged and may eventually die from intensive OSV damage 

(Pinus albicaulis is the most likely species to be damaged to this extent), OSV use is not expected to 

result in a trend toward Federal listing or loss of viability for any sensitive plants.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

305

Minimum snow depths or conditional requirements vary among the alternatives, with alternatives 1, 

2, and 4 having similar, minimal requirements that are expected to prevent direct effects to nonwoody sensitive plants. Alternative 3 requires a moderate snow depth of 18 inches for OSV use, and 

this adds a degree of protection for the shorter woody sensitive plants. Alternative 5 proposes the 

deepest snow depth of 24 inches for OSV use, and this adds an extra degree of protection for the 

shorter woody sensitive plants. Indirect effects for all species would be less in alternatives 3 and 5 

due to deeper snow requirements.

Sensitive Plant Determinations:

For two of the three sensitive woody plant species, Eriogonum umbellatum var. torreyanum and

Pinus albicaulis, due to the possibility of direct damage to individuals and minor indirect effects 

from snow compaction and OSV pollutants where they occur in areas designated for OSV use, all 

alternatives of the Tahoe OSV Use Designation project may affect individuals, but are not likely to 

result in a trend toward Federal listing or loss of viability in the planning area.

After evaluating the specific habitat requirements of each species and potential interactions with 

OSV use, minor indirect effects from snow compaction and OSV pollutants would be possible for 

any of the Sensitive plant species present in areas of high OSV use. Therefore, all alternatives of the 

Tahoe OSV Use Designation project may affect individuals, but are not likely to result in a trend 

toward Federal listing or loss of viability in the planning area for Botrychium crenulatum, 

Botrychium minganense, Bruchia bolanderi, Erigeron miser, Ivesia sericoleuca, Lewisia kelloggii

ssp. hutchisonii, Phacelia stebbinsii, and Poa sierrae.

For Lewisia serrata, alternatives 1, 3, 4, and 5 would have no effect because the species is not 

known to be present in areas of high OSV use. Because it is present in areas of high OSV use in 

alternative 2, this alternative may affect individuals, but is not likely to result in a trend toward 

Federal listing or loss of viability in the planning area for Lewisia serrata.

For Meesia uliginosa, alternatives 2 and 5 would have no effect because the species is not known to 

be present in areas of high OSV use. Because it is present in areas of high OSV use in alternatives 1, 

3, and 4, these alternatives may affect individuals, but are not likely to result in a trend toward 

Federal listing or loss of viability in the planning area for Meesia uliginosa.

Because the following species are not known to exist in areas of high OSV use, all alternatives of the 

Tahoe OSV Use Designation project would have no effect on Botrychium ascendens, Cypripedium 

fasciculatum, Fritillaria eastwoodiae, Ivesia aperta var. aperta, Lewisia cantelovii, Lewisia kelloggii

ssp. kelloggii, Lewisia longipetala, Meesia uliginosa, Peltigera gowardii, Penstemon personatus,

Phaeocollybia olivaceae, Pyrrocoma lucida, and Tauschia howellii.

Because the following species are not known to exist at all on the Tahoe National Forest, all 

alternatives of the Tahoe OSV Use Designation project would have no effect on Astragalus 

lemmonii, Astragalus pulsiferae var. coronensis, Astragalus webberi, Boechera rigidissima,

Botrychium lunaria, Botrychium montanum, Cudonia monticola, Cypripedium montanum, 

Dendrocollybia racemosa, Helodium blandowii, Ivesia aperta var. canina, Juncus luciensis,

Mielichhoferia elongata, Monardella follettii, Peltigera gowardii, and Sowerbyella rhenana.

Compliance with Relevant Laws, Regulations, Policies and Plans 

All alternatives would comply with the Endangered Species Act because no federally listed or 

proposed species would be affected. With the Biological Evaluation and Biological Assessment, the 
Over-snow Vehicle Use Designation

Tahoe National Forest

306

proposed project effects on TEPS plants have been evaluated and measures taken to ensure that 

sensitive plants do not become threatened or endangered because of Forest Service actions. All

alternatives would maintain viable populations of all native and desired nonnative plants, and the 

proposed activities were reviewed for potential effects on rare species, and thus would be compliant 

with Forest Service Manual direction. All alternatives would also comply with the Tahoe National 

Forest Land and Resource Management Plan and the Sierra Nevada Forest Plan Amendment because 

Sensitive plant populations would remain viable and their habitats would be maintained.

Other Relevant Mandatory Disclosures

Unavoidable Adverse Effects 

As described in Effects Common to All Alternatives, listed plants would not be affected. Some 

adverse effects may occur to some sensitive plants, but are not likely to cause a trend toward Federal

listing or a loss of viability.

Irreversible and Irretrievable Commitments of Resources

Although some adverse effects to sensitive plants may occur, these plants are a renewable resource 

and thus there would be no irreversible commitments of the resource. Excessive damage to 

individuals could cause mortality, and thus, may constitute an irretrievable commitment. 

Other Botanical Species

Special Interest Plants

Because OSV use and snow trail grooming may harm special interest plants and other botanical 

resources, this analysis will evaluate the direct, indirect, and cumulative effects of the alternatives on 

these botanical resources that could result from the following proposed actions:

• Designating roads, trails and areas for over-snow vehicle use

• Identification of snow trails for grooming for OSV use

• Ancillary activities such as the plowing of related parking lots and trailheads (analyzed as 

cumulative impacts)

An assessment of effects to Special Aquatic Features (Fens) is included as a subtopic within Special 

Interest Plants.

Special Interest Areas

Special interest areas (SIAs) that are designated with a botanical emphasis will be evaluated for 

consistency with maintaining the vegetation and habitat characteristics for which the SIAs were 

created.

Noxious Weeds

A Noxious Weed Risk Assessment (Botany Report, Appendix B) presents the weed species that exist 

in the project area and contains an analysis of effects from weeds and a determination of each 

alternative’s risk of introducing and/or spreading weed species in the project area. 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

307

Relevant Laws, Regulations, and Policy

Federal Law and Policy

Forest Service Manual 2670.22 (USDA Forest Service 2005) directs national forests to “maintain 

viable populations of all native and desired nonnative wildlife, fish, and plant species in habitats 

distributed throughout their geographic range on National Forest System lands.” To comply with this 

direction, Forests are encouraged to track and evaluate effects to additional species that may be of 

concern even though they are not currently listed as sensitive. Such plant species are referred to as 

special interest or watch list species.

Forest Service Manual 2900 (USDA Forest Service 2011) contains national direction for noxious 

weed management. Specific policies included in FSM 2900 include:

• Determine the risk of introducing, establishing, or spreading invasive species associated with 

any proposed action, as an integral component of project planning and analysis, and where 

necessary provide for alternatives or mitigation measures to reduce or eliminate that risk 

prior to project approval.

• Ensure that all Forest Service management activities are designed to minimize or eliminate 

the possibility of establishment or spread of invasive species on the National Forest System, 

or to adjacent areas. Integrate visitor use strategies with invasive species management 

activities on aquatic and terrestrial areas of the National Forest System. At no time are 

invasive species to be promoted or used in site restoration or re-vegetation work, watershed 

rehabilitation projects, planted for bio-fuels production, or other management activities on 

national forests and grasslands.

• Use contract and permit clauses to require that the activities of contractors and permittees are 

conducted to prevent and control the introduction, establishment, and spread of aquatic and 

terrestrial invasive species. For example, where determined to be appropriate, use agreement 

clauses to require contractors or permittees to meet Forest Service-approved vehicle and 

equipment cleaning requirements/standards prior to using the vehicle or equipment in the 

National Forest System.

Executive Order 13112 (USDA Forest Service 1999) was originally signed on Feb 3, 1999, and 

amended by Executive Order 13751 (USDA Forest Service 2016) on December 5, 2016, 

establishing the National Invasive Species Council to ensure that Federal programs and activities to 

prevent and control invasive species are coordinated, effective and efficient. EO 13112 defines an 

invasive species as “...an alien (or non-native) species whose introduction does, or is likely to cause 

economic or environmental harm or harm to human health". The Executive Orders direct Federal

agencies to prevent the introduction of invasive species, detect and respond rapidly to and control 

such species, not authorize, fund, or carry out actions that it believes are likely to cause or promote 

the introduction or spread of invasive species unless the agency has determined and made public its 

determination that the benefits of such actions clearly outweigh the potential harm caused by 

invasive species; and that all feasible and prudent measures to minimize risk of harm will be taken in 

conjunction with the actions.

Land and Resource Management Plan

Noxious weeds are identified in the Tahoe National Forest LRMP as one of five problem areas to be 

addressed with management goals and strategies. Goals for noxious weed management are to 
Over-snow Vehicle Use Designation

Tahoe National Forest

308

manage weeds using an integrated weed management approach according to the priority set forth in 

FSM 2081.2:

• Priority 1. Prevent the introduction of new invaders.

• Priority 2. Conduct early treatment of new infestations.

• Priority 3. Contain and control established infestations.

Provisions for implementing these goals are embodied in the following applicable noxious weeds 

management standards and guidelines in the Forest Plan:

• As part of project planning, conduct a noxious weed risk assessment to determine risks for 

weed spread (high, moderate, or low) associated with different types of proposed 

management activities. Refer to weed prevention practices in the Regional Noxious Weed 

Management Strategy to develop mitigation measures for high and moderate risk activities.

• When recommended in project-level noxious weed risk assessments, consider requiring offroad equipment and vehicles (both Forest Service and contracted) used for project 

implementation to be weed free. Refer to weed prevention practices in the Regional Noxious 

Weed Management Strategy.

• Minimize weed spread by incorporating weed prevention and control measures into ongoing 

management or maintenance activities that involve ground disturbance or the possibility of 

spreading weeds. Refer to weed prevention practices in the Regional Noxious Weed 

Management Strategy.

• Routinely monitor noxious weed control projects to determine success and to evaluate the 

need for follow-up treatments or different control methods. Monitor known weed 

infestations, as appropriate, to determine changes in weed population density and rate of 

spread.

Sierra Nevada Forest Plan Amendment (SNFPA). The Record of Decision (ROD) for the 2004 

Sierra Nevada Forest Plan Amendment includes the following direction applicable to motorized 

travel management and noxious weeds:

• Goals for noxious weed management are to manage weeds using an integrated weed 

management approach. Priority 1 is to prevent the introduction of new invaders. Priority 2 is 

to conduct early treatment of new infestations. Priority 3 is to contain and control established 

infestations (SNFPA ROD page 36). Applicable Standards and Guidelines for noxious weed 

management (SNFPA ROD pages 54-55, #36-41, 47-49) are listed below.

36. Inform forest users, local agencies, special use permittees, groups, and organizations in 

communities near national forests about noxious weed prevention and management.

37. Work cooperatively with California and Nevada State agencies and individual counties 

(for example, Cooperative Weed Management Areas) to: (1) prevent the introduction and 

establishment of noxious weed infestations and (2) control existing infestations.

38. As part of project planning, conduct a noxious weed risk assessment to determine risks 

for weed spread (high, moderate, or low) associated with different types of proposed 

management activities. Refer to weed prevention practices in the Regional Noxious 

Weed Management.

39. When recommended in project-level noxious weed risk assessments, consider requiring 

off-road equipment and vehicles (both Forest Service and contracted) used for project 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

309

implementation to be weed free. Refer to weed prevention practices in the Regional 

Noxious Weed Management Strategy.

40. Minimize weed spread by incorporating weed prevention and control measures into 

ongoing management or maintenance activities that involve ground disturbance or the 

possibility of spreading weeds. Refer to weed prevention practices in the Regional 

Noxious Weed Management Strategy.

41. Conduct follow-up inspections of ground disturbing activities to ensure adherence to the 

Regional Noxious Weed Management Strategy.

47. Complete noxious weed inventories, based on regional protocol. Review and update 

these inventories on an annual basis.

48. As outlined in the Regional Noxious Weed Management Strategy, when new, small weed 

infestations are detected, emphasize eradication of these infestations while providing for 

the safety of field personnel.

49. Routinely monitor noxious weed control projects to determine success and to evaluate 

the need for follow-up treatments or different control methods. Monitor known weed 

infestations, as appropriate, to determine changes in weed population density and rate of 

spread.

Special Area Designations

SIAs may have specific management objectives for unique botanical features or other features of 

interest. Botanical SIAs have been specifically designated to conserve and manage unique botanical 

communities, rare species, or other elements of biological diversity, and to provide for public 

enjoyment of these areas in a manner that is consistent with the values for which the areas were

established. On the Tahoe National Forest, no management plans are available for established 

Botanical SIAs. The Placer County Big Tree Grove is a proposed Botanical Special Interest Area 

assumed to be reserved for the protection and public enjoyment of the most northerly grove of giant 

sequoias.

Desired Condition

One stated goal in the Tahoe National Forest LRMP is to manage National Forest System lands so 

that management activities do not introduce or spread noxious or invasive exotic weeds. 

Maintaining viable populations of all native and desired nonnative plant species is the underlying 

goal of Forest Service Manual 2670.

Topics and Issues Addressed in This Analysis

Purpose and Need

Botanical resources are not directly related to the purpose and need for action, but several public 

comments raised concerns about OSV damage to vegetation. Concerns for botanical resources are 

not among the key issues that drove development of additional action alternatives.

Issues

OSV uses may cause direct and indirect effects to survey and manage plants, special interest plants, 

and invasive plants, but are most likely to affect those that have living tissues present within the 

snow column each season (such as trees or shrubs). Several public comments have been received that 

raise concerns about the effects of OSV use on general vegetation and rare species. Effects may be 

either direct by damage or death to individual plants from OSV (stem breaking, crushing, etc.), or 
Over-snow Vehicle Use Designation

Tahoe National Forest

310

indirect by increasing the opportunity for pathogens to attack damaged plant tissues or by altering 

habitat. Possible effects include but are not limited to: physical damage to plants and habitats;

reduced seed production; decreased plant vigor; changes in hydrology; changes to soils, especially 

erosion and sedimentation; changes in physiological responses; and increases in risk of weed 

introduction and spread. These effects become much more likely if OSV use occurs where or when 

there is inadequate snow depth. 

Some plant species emerge from the ground very early in the growing season and subsequent 

snowfall may accumulate enough afterward to allow authorized OSV use. In these cases, living plant 

tissues may also be impacted by OSV use. Compaction of snow may lead to changes in plant 

composition and habitat suitability. Weed seeds may be transported into areas designated for OSV 

use. When snow cover is not adequate, OSV use on and off established routes can affect some survey 

and manage plants, special interest plants, and their habitats. The proposed minimum snow depth 

requirements are presumed to be sufficient to protect the majority of plant species from damage.

Resource Indicators and Measures 

Resource indicators and measures shown in table 19 will be used to measure and disclose effects to 

botanical resources related to OSV use designations and grooming trails for OSV use.

Table 102. Botanical resources indicators and measures for assessing effects 

Resource 

Element Resource Indicator Measure

Vegetation Species presence Acres of special interest plant occurrences within open 

OSV use areas.

Acres of special interest plant occurrences within highuse areas.

Qualitative discussion of species’

responses to proposed activities 

Special interest plants effects determination.

Noxious/invasive weed presence Acres of weed infestations within open OSV use areas.

Acres of weed infestations within high-use areas.

Noxious/invasive weed response 

to proposed activities

Level of risk (high, moderate, low) for the project 

introducing or spreading weeds.

Presence of designated botanical 

resource areas 

Acres of botanical resource areas within open OSV use 

areas.

Acres of botanical resource areas within high-use 

areas.

Methodology

This analysis used ArcMap and relevant Geographic Information System (GIS) data layers from the 

Tahoe National Forest. The GIS layers of proposed OSV designations and groomed trails were

overlain with the botanical resource layers to identify areas of potential effects. 

Special interest plants that are known to occur within the planning area are presented in table 103.

Effects to each special interest species were evaluated based on growth form, timing of important life 

cycle elements (i.e. emergence, flowering, seed production, germination, etc.), identified threats, 

important habitat components, and the expected interaction with disturbances associated with OSV 

use and snow trail grooming.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

311

Information Sources 

Information used in this analysis includes pertinent scientific literature, project-specific botanical 

data, results of surveys and site revisits, and GIS layers of the following data: project boundary, 

actions by alternative, and Tahoe National Forest TEPS/special interest plant occurrences. Because 

some special interest plant occurrence data is lacking in the Tahoe National Forest data (specifically 

for Carex davyi, Corallorhiza trifida, Rhamnus alnifolia, Schoenoplectus subterminalis, Stachys 

pilosa, and Stuckenia filiformis), supplemental data is provided by the California Natural Diversity 

Database (October 2017 Monthly Update).

Incomplete and Unavailable Information 

There is little research and information available regarding the responses of each plant species or 

whole plant communities to OSV uses, including indirect effects from snow compaction and vehicle 

emissions during the winter.

Assumptions specific to the botanical resources analysis:

• High-use areas are defined in this analysis as open areas within 0.5 mile of designated OSV 

trails. The trails themselves are considered high-use regardless of designation of adjacent 

areas.

• Plants are unlikely to be directly affected by authorized OSV use (with the specified 

requirements of specific snow depths or adequate snow depth to avoid damage to resources –

typically 12 inches) when their living tissues are not present above ground. Therefore, 

typically, only shrub or tree species are likely to be directly affected by OSV use.

• Indirect effects, such as those possibly resulting from snow compaction and vehicle 

emissions, are likely to be concentrated in the corridors along designated OSV trails 

(groomed or ungroomed). Therefore, an area within 0.5 mile of designated OSV trails is 

reasonably assumed to be affected by snow compaction, emissions, or other contamination.

Because OSV use is expected to be concentrated in the designated OSV trail corridor, and 

grooming activities are restricted to identified trails, areas designated for OSV use outside 

these concentrated use corridors are much less likely to experience measurable indirect 

effects.

• Over-snow vehicles, towing vehicles, or trailers may carry mud or other debris containing 

weed seeds from infested areas to trailheads and possibly indirectly into any areas designated 

for OSV use.

• Only authorized OSV uses will be analyzed. Concerns arising from unauthorized uses will 

be addressed as law enforcement issues and may prompt corrective actions. 

• Resource monitoring will identify unexpected types or levels of impacts to botanical 

resources, and may also prompt corrective actions as warranted.

Spatial and Temporal Context for Effects Analysis

Direct and Indirect Effects Boundaries

The spatial boundary for analyzing the direct and indirect effects to these botanical resources is the 

project area boundary, because all expected effects relevant to these resources would occur and 

remain within this area. Effects to vegetation would be expected to have occurred or become evident 

within one or two years of disturbance and this constitutes the short term. Effects that linger beyond 
Over-snow Vehicle Use Designation

Tahoe National Forest

312

2 years are considered long-term effects, and may extend to decades or centuries. Such long-term 

effects beyond 20 years become increasingly difficult to predict due to unknown interactions and the 

many environmental variables with numerous possible outcomes.

Cumulative Effects Boundaries

Because effects from the proposed activities would interact with effects from other ongoing or future 

projects only within the project area boundary, the cumulative effects boundary is also the project 

area boundary. Cumulative effects are considered for a time period within 20 years of project 

implementation.

Affected Environment

Existing Condition 

Special Interest Plants

Often referred to as “watch list” species, Special interest plants are species that do not meet all of the 

criteria to be included on the Regional Forester’s sensitive plant list, but are of sufficient concern to 

consider them in the planning process. The Tahoe National Forest watch list includes species that are 

newly described; locally rare; range extensions or disjunct populations; species of specific public 

interest; or species with too little information to determine their appropriate status. Watch lists are 

dynamic and updated as the need arises to reflect changing conditions and new information. Such 

species make an important contribution to forest biodiversity and are addressed as appropriate 

through the NEPA process. Sixty-one special interest plants are known or suspected to occur on the 

Tahoe National Forest. Special aquatic features (fens) are also included in this topic. See table 103

below.

Table 103. Special Interest plant species and communities considered

Scientific Name

Common Name Habitat Life Form

Allium jepsonii

Jepson’s onion

Foothill woodland, lower montane coniferous forest, 

serpentine or volcanic soils. 900-4,400 feet. Flowers AprilAugust.

Perennial 

herb

Allium sanbornii var.

congdonii

Congdon’s onion

Serpentinite or volcanic substrates in chaparral or 

cismontane woodland.1,000-5,000 feet. Flowers April-July.

Perennial 

herb

Allium sanbornii var. sanbornii

Sanborn's onion

Usually serpentinite, gravelly areas in chaparral, 

cismontane woodland, or lower montane coniferous 

forest.1,000-5,000 feet. Flowers May-September.

Perennial 

herb

Arctostaphylos mewukka ssp.

truei

True’s manzanita

Sometimes roadside, in chaparral or lower montane 

coniferous forest. 1,400-4,560 feet. Flowers February-July. 

Evergreen 

shrub

Arctostaphylos nissenana

Nissenan manzanita

Chaparral/closed-cone pine forest. 1,500-3,500 feet. 

Flowers February-March. 

Evergreen 

shrub

Calochortus clavatus ssp. 

avius 

Clubhair mariposa lily

Forest edges, lava caps, 3,000-5,800 feet. Flowers MayJuly. Perennial 

herb

Calystegia vanzuukiae 

Van Zuuk’s morning-glory

Serpentine/gabbro soils, 1,640-3,875 feet. Perennial 

herb
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

313

Scientific Name

Common Name Habitat Life Form

Cardamine pachystigma var. 

dissectifolia serpentine 

bittercress

Openings, usually serpentinite, rocky, in chaparral or lower 

montane coniferous forest. Below 6,900 feet. Flowers 

February-May. 

Perennial 

herb

Carex davyi

Davy’s sedge

Dry, often sparse meadows and slopes, subalpine/red fir 

forest, 4,800-10,600 feet. Flowers May-Aug. 

Perennial 

herb

Carex lasiocarpa

woolly fruit sedge

Fens, wet areas, 1,900-6,900 feet. Flowers June-July. Perennial 

herb

Carex limosa

Mud sedge

Fens, wet areas, 4,000-8,700 feet. Flowers June-August. Perennial 

herb

Carex praticola

Meadow sedge

Meadows/wet areas, 1,600-10,500 feet. Flowers May-July. Perennial 

herb

Carex sheldonii

Sheldon’s sedge

Wet areas, 4,000-5,000 feet. Flowers May-Aug. Perennial 

herb

Ceanothus arcuatus

Arching ceanothus

Serpentine soils, 1,900-7,025 feet. Flowers April-June. Shrub

Chlorogalum grandiflorum

Red hills soaproot

Serpentine, gabbroic soils, 800-4,100 feet. Flowers MayJune. Perennial 

herb

Clarkia biloba ssp. 

brandegeae

Brandegee’s clarkia

Forest edges/openings, less than 3,100 feet. Flowers MayJuly. Annual herb

Clarkia mildrediae ssp. 

lutescens

Mildred’s clarkia

Woodland/forest edges, less than 5,750 feet. Flowers JuneAugust. Annual herb

Clarkia mildrediae ssp. 

mildrediae

Mildred’s clarkia

Woodland/forest edges, 800-5,650 feet. Flowers MayAugust.Annual herb

Claytonia megarhiza

Alpine springbeauty

Talus/rock crevices, above 8,000 feet. Flowers JulySeptember. Perennial 

herb

Corallorhiza trifida

Yellow coralroot 

Wet areas. 4,450-5,750 feet. Flowers June-July. Perennial 

herb

Darlingtonia californica

California pitcherplant

Wetlands/riparian, 0-8,500 feet. Flowers April-July. Perennial 

herb

Drosera anglica

English sundew

Bogs, fens, wetland/riparian, less than 8,500 feet. Flowers 

June-September. 

Perennial 

herb

Epilobium howellii

Yuba Pass willowherb

Meadows and seeps, wetland/riparian. 6,000-9,000 feet. 

Flowers July-August.

Perennial 

herb

Epilobium luteum

Yellow willowherb

Wetland areas, 4,900-5,600 feet. Flowers July-September. Perennial 

herb

Eremogone cliftonii

Clifton’s eremogone

Openings, usually granitic, in chaparral and montane 

coniferous forests. 1,490-5,850 feet. Flowers AprilSeptember. 

Perennial 

herb

Erigeron petrophyllus var.

sierrensis 

northern Sierra daisy

Serpentinite soils, 900-5,700 feet. Flowers June-October. Perennial 

herb
Over-snow Vehicle Use Designation

Tahoe National Forest

314

Scientific Name

Common Name Habitat Life Form

Eriogonum umbellatum var. 

ahartii 

Ahart’s buckwheat

Serpentinite, slopes, openings in chaparral or cismontane 

woodlands, less than 5,600 feet. Flowers June-September. 

Perennial 

herb/subshru

b

Glyceria grandis

American mannagrass

Riparian/wetland areas, below 6,890 feet. Flowers JuneAugust.Perennial 

herb

Hemieva ranunculifolia 

Buttercup-leaf suksdorfia

Riparian/wetland/mesic, rocky, granitic areas, 4,900-8,200 

feet. Flowers June-August.

Perennial 

herb

Horkelia parryi

Parry’s horkelia

Grows in openings and edges, on Ione formation and other 

soils, in chaparral or cismontane woodland, below 3,400 

feet. Flowers April-September.

Perennial 

herb

Lilium humboldtii ssp. 

humboldtii 

Humboldt lily

Openings in chaparral, cismontane woodland, or lower 

montane conifer forests. Flowers May-August. 

Perennial 

herb

Lycopus uniflorus

Northern bugleweed

Fens, marshes, swamps, below 6,600 feet. Flowers JulySeptember. Perennial 

herb

Meesia longiseta

Meesia moss

Carbonate substrates, on soil in fens, meadows, and seeps 

in upper montane coniferous forest, all elevations.

Bryophyte, 

moss 

(perennial 

herb)

Meesia triquetra

Meesia moss

Fens, meadows, and seeps in upper montane coniferous 

forest or subalpine areas, 4,200-9,700 feet. 

Bryophyte, 

moss 

(perennial 

herb)

Micranthes howellii

Howell’s saxifrage

Wetland/riparian areas, sometimes serpentinite, in 

cismontane woodland, below 3,000 feet. Flowers MarchMay.

Perennial 

herb

Mimulus glaucescens

Shieldbract monkeyflower

Serpentinite seeps, sometimes streambanks, in chaparral, 

cismontane woodland, lower montane coniferous forest, or 

valley and foothill grassland habitats, below 4,100 feet. 

Flowers February-September. 

Annual herb

Mimulus laciniatus 

Cutleaf monkeyflower

Granitic seeps in chaparral or montane coniferous forest, 

3,300-8,700 feet. Flowers April-July.

Annual herb

Oreostemma elatum

Plumas alpine aster

Fens, meadows, and seeps in upper montane coniferous 

forest, 3,200-6,700 feet. Flowers June-August.

Perennial 

herb

Packera eurycephala var. 

lewisrosei

Lewis’ groundsel

Serpentine soils in chaparral, cismontane woodland, or 

lower montane coniferous forest, 900-6,200 feet. Flowers 

March-September.

Perennial 

herb

Penstemon sudans

Susanville beardtongue

Volcanic, rocky places, sometimes roadsides, in Great 

Basin scrub, lower montane coniferous forest, or pinyon 

and juniper woodland, 3,900-8,000 feet. Flowers JuneSeptember.

Perennial 

herb

Perideridia bacigalupi

Mother lode yampah

Serpentine soils, in chaparral and pine woodlands, 1,400-

3,400 feet. Flowers June-August.

Perennial 

herb

Piperia colemanii

Coleman’s piperia

Chaparral, duff in lower montane coniferous forest, often 

shaded. 3,900-7,600 feet. Flowers June-August. 

Perennial 

herb

Potamogeton praelongus

whitestem pondweed

Deep water, lakes. 5,900-9,850 feet. Flowers July-August. Aquatic 

perennial 

herb
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

315

Scientific Name

Common Name Habitat Life Form

Pseudostellaria sierrae

pseudostellaria

Forest edges/openings, 4,000-7,200 feet. Flowers MayAugust. Perennial 

herb

Rhamnus alnifolia

Alderleaf buckthorn

Wetland/riparian areas, 4,500-7,000 feet. Flowers May-July. Deciduous 

shrub

Rhynchospora alba

white beaksedge

Wetland/riparian areas, 150-6,700 feet. Flowers JulyAugust. Perennial 

herb

Rhynchospora capitellata

Brownish beaksedge

Wetland/riparian areas, 150-6,600 feet. Flowers JulyAugust.Perennial 

herb

Sanicula tracyi

Tracy’s blacksnakeroot

Openings/edges in cismontane woodland or montane 

coniferous forest. 300-5,200 feet. Flowers April-July.

Perennial 

herb

Schoenoplectus subterminalis

Swaying bulrush

Fens, montane lake margins. 2,400-7,400 feet. Flowers 

June-September.

Aquatic 

perennial 

herb

Scutellaria galericulata 

marsh skullcap

Streambanks, marshes, swamps, meadows, seeps. 4,000-

7,000 feet. Flowers June-September. 

Perennial 

herb

Sidalcea gigantea

Giant checkerbloom

Wetland/riparian areas, meadows and seeps in montane 

coniferous forest. 2,100-6,400 feet. Flowers JanuaryOctober.

Perennial 

herb

Sedum albomarginatum 

Feather River stonecrop

Steep cliffs and mountain slopes in rocky serpentine 

substrates, riparian/river canyons, 850-6,400 feet. Flowers 

May-June.

Perennial 

herb

Silene occidentalis ssp. 

longistipitata

Western catchfly

Forest edges/openings in chaparral or montane coniferous 

forest, 3,200-6,600 feet. Flowers June-August.

Perennial 

herb

Silene occidentalis ssp. 

occidentalis

Western catchfly

Forest edges/openings in chaparral or montane coniferous 

forest, 4,000-6,900 feet. Flowers June-August.

Perennial 

herb

Sphagum species

Peat moss

Fens/ peatlands, all elevations. Perennial 

herb

Stachys pilosa

Hairy hedgenettle

Wetland/riparian areas in Great Basin scrub. 3,900-5,850 

feet. Flowers June-August.

Perennial 

herb

Stellaria obtusa 

Rocky Mountain chickweed

Forest edges/openings, 5,200-6,600 feet. Flowers JuneAugust. Perennial 

herb

Stuckenia filiformis

Fineleaf pondweed

Marshes and swamps (assorted shallow freshwater), 980-

7,055 feet. Flowers May-July.

Aquatic 

perennial 

herb

Tonestus eximius

Lake Tahoe serpentweed

Granitic, subalpine forest, 8,000-10,000 feet. Flowers JulyAugust.Perennial 

herb

Utricularia minor

lesser bladderwort

Shallow water, above 1,500 feet. Flowers in May-August. Aquatic 

perennial 

herb

Veronica cusickii

Cuskick’s speedwell

Moist soils, alpine boulder and rock fields, meadows, and 

seeps, above 6,500 feet. Flowers July-August.

Perennial 

herb

Special Aquatic Features -

Fens

Wet areas, all elevations. Approximately 52 acres of fen 

habitats are mapped on the Tahoe National Forest.

-
Over-snow Vehicle Use Designation

Tahoe National Forest

316

Special Interest Species Information

Aggregating Species for Analysis of Effects

Because OSV effects to various plant species are expected to be most similar according to their life 

form and growth habits, the species considered in this analysis are grouped into the following 

categories:

• Trees, shrubs, or sub-shrub species, (woody plants) whose living tissues may be present 

above or within the snow column, and thus could experience direct effects from OSV uses 

(physical damage or immediate exposure to exhaust). On the Tahoe National Forest, five 

special interest plants are in this category. 

• Perennial herbaceous species, including grasses, fungi, and mosses, whose living tissues 

are at or below the soil surface, and thus are unlikely to experience direct effects, but they 

will be evaluated for impacts by exhaust contaminants trapped by the snow cover or by 

possible effects from snow compaction. Forty-seven special interest plant species in this 

category are considered.

• Annual plant species are generally not growing during the period of authorized OSV use, 

and thus would not experience direct effects. This group is the least likely to be impacted by 

the indirect effects of exhaust contaminants and snow compaction. Five annual special 

interest plant species are considered in this analysis.

• Aquatic plant species grow underwater and would not be directly affected by OSV use. If 

an occurrence is located within high-use areas, it is possible that snowpack contaminants 

could reach the occupied aquatic habitat when the snow melts. Snow compaction is not 

expected to affect aquatic habitats in any meaningful or predictable manner. In this analysis,

four aquatic special interest plant species are considered.

Special Aquatic Features – Fens

Fens are peat-forming wetlands, supported by nearly constant groundwater inflow. Their permanent 

saturation creates oxygen-deprived soils with very low rates of decomposition, allowing the 

accumulation of organic matter produced by wetland plants. Fens also are hotspots of biological 

diversity. In California, the perennial supply of water provides refugia for plant and animal species 

that persist only in fens. Fens were determined to be particularly important for their biological 

diversity and as habitat for species of Sphagnum, Meesia, and other bryophytes. 

Special Interest Areas

One special interest area is designated as a Botanical Area, and it is not deignated for OSV use.

Placer County Big Trees Grove is the most northerly stand of naturally occurring Giant Sequoias, 

Sequoiadendron giganteum, and is 357 acres in size and is located 22 miles east of Foresthill 

overlooking the Middle Fork American River. The northern end of this SIA is bordered by a 

designated OSV trail. This area has been designated as a Botanical Special Interest Area. The trees 

have been a popular tourist attraction since the 1800s, and each bears the name of a prominent 

American. A nature trail and picnic area offer visitors a nice lunch or rest stop.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

317

Environmental Consequences

Effects common to all alternatives

Because the alternatives are very similar, with the same activities proposed, and the differences are 

mainly the spatial extent of OSV use, most of the effects are described in this section. The varying 

areas of authorized OSV use would result in mostly small differences in degree of potential effects. 

Therefore, each alternative’s effects will mainly summarize the extent of botanical resources 

affected, and provide the basis for determinations. A summary comparison of alternatives will follow, 

providing the decision-maker a quick reference for evaluating the alternatives along with the other 

resources that need to be considered. Detailed results of botanical resource measures for each 

alternative, by species, is presented in table 109.

Special Interest Plants

Effects analyses for special interest plants are presented in categories of plant life forms because the 

greatest possible impacts from OSV activities are dependent upon the presence of their living tissues 

within the snow or above the snow surface and whether each species is biologically active during the 

times that direct and indirect effects may occur. Effects to each life form category are presented after 

an introduction of direct and indirect effects. 

Direct Effects 

A key difference between OSV use and other types of motor vehicle use is that, when properly 

operated and managed, OSVs do not make direct contact with soil, water, and ground vegetation, 

whereas most other types of motor vehicles operate directly on the ground (USDA Forest Service 

2014). OSV use and grooming of OSV trails can damage vegetation through direct contact with plant 

tissues that are present above the snow or within the snow column that is compacted by the vehicles. 

Because woody species (trees, shrubs, and sub-shrubs) are the only plants present within the snow, 

they are the only plants that are likely to be directly damaged. All other plant life forms are not 

expected to be directly affected by OSV use because adequate snow requirements and minimum 

snow depths are expected to prevent direct effects to vegetation at ground level.

It is generally recognized that disturbance to soil and vegetation by OSV use is reduced as snowpack 

depths increase. Damage to soil and low-growing vegetation is much more likely when OSV use 

occurs under low-snow conditions (Greller et al. 1974, Fahey and Wardle 1998). Thus, the 

requirement of adequate snow to avoid damage to resources for alternative 2, and the specific 

minimum snow depths for alternatives 3, 4, and 5 are expected to prevent or minimize damage to soil 

and ground vegetation.

In a study on Niwot Ridge in the Front Range of the Colorado Rocky Mountains, repeated 

snowmobile use occurred on snow-covered and snow-free areas between two weather stations, and 

the effects of this use were evaluated (Greller et al. 1974). General conclusions included: (1) in 

communities that are snow-free in winter, damage by snowmobiles was severe to lichens, 

Selaginella, and to relatively prominent, rigid cushion-plants. Part of the damage to these 

communities may have been due to the manual removal of rocks, necessary for the operation of 

snowmobiles in snow-free areas; (2) Kobresia, present in isolated tussocks in a cushion-plant 

community, absorbed the major portion of snowmobile impact. As Kobresia is thought to form the 

climatic climax community in this ecosystem, differential damage to it could seriously retard 

succession; (3) Snowmobile travel in uniform, closed Kobresia meadows inflicted much less damage 

to most plants, including Kobresia itself, than did similar travel on a sparsely vegetated community;
Over-snow Vehicle Use Designation

Tahoe National Forest

318

(4) Plants best able to survive the heaviest snowmobile impact were those with small stature and 

little woodiness, or with buds well-protected at or below the soil surface; (5) Snowmobile traffic 

should be carefully restricted to snow-covered areas. Whenever this is not feasible, the least 

destructive and easiest alternative is travel on mature, well-vegetated Kobresia meadows or similar 

well-drained plant communities.

On the Tahoe National Forest, OSV travel on snow-free areas is prohibited in the current and 

proposed scenarios. By not allowing OSV use when and where there is less than adequate snow to 

avoid damage to resources (typically 12 inches for cross-country use) or designating specific snow 

depth requirements, the Tahoe National Forest minimizes the possibility of direct damage to soils 

and ground vegetation. 

Indirect Effects 

Indirect effects are caused by the action and occur later in time or are farther removed in distance, 

but are still reasonably foreseeable. Three specific topics of indirect effects were identified: snow 

compaction, pollutants, and invasive plant species. Potential effects from snow compaction and 

pollutants are described below, and a discussion of potential invasive plant effects will follow in its 

own section because it is a required analysis topic itself.

Snow Compaction

Snow is compacted by any of the allowed OSVs, including snowmobiles, snow cats, and snow 

grooming equipment. Snow compaction mechanically alters snow grains and redistributes them. This 

mechanical disturbance breaks off the small points of new snow crystals, destroying the weak 

existing bonds between them, and bringing the new grains into much closer contact than occurs 

naturally. Snow metamorphism is artificially accelerated, and snow density and hardness are 

increased. In addition, the layered structure of the snowpack is changed (Fahey and Wardle 1998). 

All this has both thermal and hydrological implications, resulting in lower soil temperatures (Fahey

and Wardle 1998, Eagleston and Rubin 2012) and delayed snowmelt (Keddy et al. 1979, Fahey and 

Wardle 1998, Davenport and Switalski 2006, Gage and Cooper 2013). The thermal conductivity of 

compacted snow is greater than undisturbed snow, and can reduce the buffering effect against 

temperature extremes and fluctuations. Thermal conductivity of compacted snow was 11.7 times 

greater than non-compacted snow (Neumann and Merriam 1972).

Keddy and others (1979) studied the effects of snowmobile use on snow compaction, vegetation 

composition, and soil temperatures on an abandoned farm in Nova Scotia. They found that snow 

melted later in areas with compacted snow and that some species showed differences in cover 

between treatments. Considering the multitude of possible effects and the variety of plant structures 

and life histories, they were not surprised to find no overall trend for species composition changes. 

They also noted that the first pass by a snowmobile caused the greatest increase in snow compaction 

– roughly 75 percent of that observed after 5 sequential passes. While some species composition 

changes were observed in old field vegetation, they found no changes in species composition in a 

marsh area, possibly because of solid ice cover during the winter.

In a study of the impact of snowshoe/cross-country ski compaction and snowmelt erosion on 

groomed trails, Eagleston and Rubin (2012) reported that these non-motorized uses caused snow to 

remain on the compacted areas an average of 5 days longer than non-compacted areas. They also 

found that the compacted snow caused increased erosion. Soil temperatures under compacted snow 

stayed frozen for 3 days longer, and, averaged over the entire winter season, remained 0.1 degree 

Celsius colder than soil under non-compacted snow.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

319

Fahey and Wardle (1998) examined the effects of snow grooming for downhill ski areas in subalpine 

and alpine environments. They found that the compacted snow increased frost penetration and 

delayed snowmelt.

However, research does not always support the generalization of lower soil temperatures and delayed 

snowmelt due to snow compaction. In a study of snow compaction effects from snowmobiles on fens 

on the Routt National Forest, Gage and Cooper (2013) found no statistically significant differences 

in the temperature of peat soils between compacted and non-compacted areas. They also found no 

differences in timing of snowmelt, biomass production, or plant phenology. From additional, 

unpublished data from the Telluride Ski Area, where intense compaction occurred daily, they 

observed a delayed snowmelt and thawing of the soil of about one month in compacted areas. They 

noted that the continuous influx of groundwater in fens may limit freezing and maintain more 

constant soil thermal conditions. They found no evidence conclusively linking snowmobile 

compaction to impairment of fen function.

Different plants have different levels of vulnerability and ability to recover from the effects of snow 

compaction. The characteristics which determine their vulnerability are the timing of flowering, and 

growth form and size (Fahey and Wardle 1998). Prolonged snow lie may adversely affect early 

spring flowering plants because they could have a shorter growing season and thus possibly reduced 

seed production due to delayed phenology and perhaps a misalignment of timing with their preferred 

pollinators. Due to snow compaction, early spring growth of some plant species may be retarded or 

may not occur under an OSV trail; however, the current and proposed OSV trails are underlain by 

existing roads and trails which are already compacted and/or disturbed and little, if any, additional 

impacts are expected to the vegetation.

Trail grooming on the Tahoe National Forest occurs mostly over an existing road and trail network. 

The grooming does not alter landforms or result in significant soil disturbance that would change 

water flow patterns or quantities of surface water runoff.

In summary, the available research supports the assumption that more intensive snow compaction 

occurring along groomed or heavily used trails would have considerably greater effect on soil 

temperatures and delayed snowmelt than the compaction caused by dispersed uses in areas open to 

cross-country OSV use. Due to the intensive, repetitive, and predictable compaction of snow along 

designated OSV trails (groomed or not), these areas are much more likely to have a degree of 

compaction that could adversely influence vegetation. Therefore, in this analysis, areas within 

one-half mile of designated OSV trails are assumed to be at risk from the effects of snow 

compaction. Outside the designated OSV trail corridors, dispersed OSV travel is much less likely to 

compact snow with enough intensity and repetition to measurably or predictably affect ground 

vegetation, and therefore is not considered in this analysis as an expected source of indirect effects.

Pollutants

Emissions from over-snow vehicles, particularly two-stroke engines on snowmobiles, release 

pollutants including ammonium, sulfate, benzene, nitrogen oxides, ozone, carbon dioxide, carbon 

monoxide, aldehydes, polycyclic aromatic hydrocarbons and other toxic compounds into the air. A 

portion of these compounds may become trapped and stored in the snowpack, to be released during 

spring runoff. Four-stroke snowmobile engines produce considerably lower amounts of pollutants.

Pollutants emitted from exhaust can cause a variety of impacts on vegetation. Carbon dioxide may 

function as a fertilizer and cause changes in plant species composition (Bazzaz and Garbutt 1998); 
Over-snow Vehicle Use Designation

Tahoe National Forest

320

nitrogen oxides also may function as fertilizers, producing similar effects along roadsides 

(Falkengren-Grerup 1986). Sulfur dioxide, which can be taken up by vegetation, may result in 

altered photosynthetic processes (Winner and Atkison 1986, Mooney et al. 1988). Other toxic 

compounds may result in reduced metabolism or retarded growth.

Although a large portion of OSV exhaust is expected to be dissipated into the air, some of the 

airborne pollutants would enter the snowpack and be released during snowmelt. Similar responses 

can be assumed to occur in plants that ingest these compounds from snowmelt, although the 

compounds may undergo chemical changes while in the snowpack, confounding the predictability of 

effects.

Airborne pollutants can enter the snowpack from both local and regional sources, including but not 

limited to vehicle emissions, dust storms, and smog. The concentrations of basic cations and acidic 

anions in the snowpack can be altered and, when released quickly during snowmelt, can temporarily 

lower the pH of surface waters in a process known as “episodic acidification” (Blanchard et al.

1988). Soil acidification and vegetation changes were examined in southern Sweden, where 

Falkengren-Grerup (1986) found that increased nitrogen deposition and the increased acidity in the 

humus layer may have caused changes in plant cover, with some species increasing and some species 

decreasing.

Demonstrating that snowpack chemistry can be used as a quantifiable indicator of airborne pollutants 

from vehicular traffic, a correlation was shown between pollutant levels and vehicle traffic in 

Yellowstone National Park (Ingersoll et al. 1997). Ammonium and sulfate levels were consistently 

higher for the in-road snow compared to off-road snow, but nitrate concentrations did not decrease 

within a distance of 100 meters from the emission source; thus, the nitrate ion may be used to 

distinguish between local and regional emission sources (Ingersoll et al. 1997). Studying snow 

chemistry in Yellowstone National Park, Ingersoll (1998) found that concentrations of ammonium, 

nitrate, sulfate, benzene, and toluene were positively correlated with snowmobile use. Concentrations 

of ammonium were up to three times higher for the in-road snow compared to off-road snow. 

Concentrations decreased rapidly with distance from roadways.

Arnold and Koel (2006) also examined volatile organic compounds in Yellowstone National Park, 

and found that the snow in heavily used areas contained higher levels of benzene, ethylbenzene, mand p-xylene, o-xylene, and toluene compared with a control site only 100 meters from the traveled 

roadways. Even at the most heavily used area (Old Faithful) they found that the concentrations of 

volatile organic compounds were considerably below the EPA’s water quality criteria for these 

compounds. In situ water quality measurements (temperature, dissolved oxygen, pH, specific 

conductance, and turbidity) were collected; all were found within acceptable limits. Five volatile 

organic compounds were detected (benzene, ethylbenzene, m- and p-xylene, o-xylene, and toluene). 

The concentrations were found below EPA criteria and guidelines for the volatile organic compounds 

analyzed and were below levels that would adversely impact aquatic ecosystems (Arnold and Koel 

2006).

Studying air quality and snow chemistry effects from snowmobiles in the Snowy Range, Wyoming, 

Musselman and Korfmacher (2007) found that heavier snowmobile use resulted in higher levels of 

nitrogen oxides and carbon monoxide, but ozone and particulate matter were not significantly 

different. When compared with air quality during the summer, they found that carbon monoxide 

levels were higher in the winter, but nitrogen oxides and particulate matter were higher in the 

summer. Air pollutants were well-dispersed and diluted by winds, and air quality was not perceived 

as being significantly affected by snowmobile emissions. Pollutant concentrations were generally 

low in both winter and summer. These results differ from those studies examining air pollution from 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

321

snowmobiles in Yellowstone National Park. However, snow chemistry observations did agree with 

studies from Yellowstone National Park. Compared with off-trail snow, the snow sampled from 

snowmobile trails was more acidic with higher amounts of sodium, ammonium, calcium, 

magnesium, fluoride, and sulfate. Snowmobile activity apparently had no effect on nitrate levels in 

the snow.

In the winter, plant metabolic rates are drastically reduced. Airborne compounds would only be taken 

up by respiring woody plants. Airborne pollutants normally disperse quickly in mountain 

environments that are prone to windy conditions, such as the Sierra Nevada. Different plants may 

have different responses to the different pollutants in the snowpack, including damage from toxic, 

volatile compounds and possibly some benefits from additional nutrients and trace minerals. The 

levels of OSV exhaust contaminants on the Tahoe National Forest (considerably less than those 

observed in Yellowstone National Park) are not expected to impair water quality (McNamara 2016). 

In a natural plant community with many species competing for resources, and very little research 

done on each species’ responses to OSV emissions or the competitive interactions that may be 

affected, it is nearly impossible to predict what changes, if any, would occur. It can only be 

reasonably assumed that there may be some changes in plant species cover and composition. The 

uptake of harmful pollutants is not expected to result in the death of any individual plants. On the 

Tahoe National Forest, no mortality of roadside TES plants due to vehicle pollutants has been 

observed, even considering year-round vehicle uses. Therefore, the level of effect to TES plants from 

OSV pollutants is expected to be minimal, and would not result in loss of individuals.

The available research on OSV pollutants (both airborne and in the snowpack) indicate that some 

effects to vegetation may occur in the immediate vicinity of heavy use areas. Pollutants that become 

trapped in the snowpack are also expected to be concentrated in areas of heavy OSV use. Therefore, 

in this analysis, areas within one-half mile of designated OSV trails (groomed or not) are 

assumed to be reasonably at risk from the effects of OSV pollutants. Outside the designated OSV 

trail corridors, dispersed OSV travel is much less likely to contribute harmful contaminants with high 

enough levels and repetition to measurably or predictably affect ground vegetation, and therefore is 

not considered in this analysis as an expected source of indirect effects.

Relative Potential Effects to Plant Life Forms

Considering the combination of direct and indirect effects described above, and the requirement of 

adequate snow to avoid resources or minimum snow depth requirements of the alternatives, the 

effects of proposed OSV uses can be broken down into relative categories of potential damage to the 

major plant life forms. From the most likely to least likely to experience measurable effects:

• Evergreen trees and shrubs – most likely to be directly affected, due to mechanical damage; 

indirect effects are expected if the species occurs in high-use areas. Direct effects may occur 

in all areas designated for OSV use.

• Deciduous trees and shrubs – somewhat less likely, due to winter dormancy; indirect effects 

are expected if the species occurs near designated OSV trails. Effects may occur in all areas 

designated for OSV use.

• Sub-shrubs (low-growing woody species) – less likely due to less exposure to direct effects 

(but still expected); indirect effects may be expected if the species occurs in high-use areas.

Direct effects may occur in all areas designated for OSV use.
Over-snow Vehicle Use Designation

Tahoe National Forest

322

• Perennial herbaceous species – direct effects are not expected to occur due to the 

requirement of adequate snow to avoid resource damage or minimum snow depths; indirect 

effects may be expected if the species occurs in high-use areas. Indirect effects may occur 

along designated OSV trails, but are not likely in areas open to cross-country OSV use.

• Annual species – direct effects are not expected to occur due to the requirement of adequate 

snow to avoid resource damage or minimum snow depths; indirect effects might be expected 

if the species occurs in high-use areas and if spring flowering were to be altered by persistent 

compacted snow. Effects may occur along designated OSV trails, but are not likely in areas 

open to cross-country OSV use. Depending on their specific habitats, annual plants may or 

may not be indirectly affected by delayed snowmelt or pollutants.

• Aquatic species – direct effects would not occur because OSV use is not allowed over open 

water; indirect effects from pollutants might be expected if the species occurs in high-use

areas. No effects are expected to aquatic species from delayed snowmelt. Indirect effects 

from pollutants may occur in high-use areas, but are not likely in other areas open to crosscountry OSV use.

Trees, shrubs, or sub-shrub species

Direct Effects

Snowmobile activities may damage vegetation on and along trails and in area open to cross-country

OSV use. The most commonly observed effect from snowmobiles was the physical damage to 

shrubs, saplings, and other vegetation (Neumann and Merriam 1972, Wanek 1971). Winter Wildland

Alliance (WWA) analyzed the Gallatin National Forest regeneration survey data collected between 

1983 and 1996 in areas that were harvested and replanted. That survey data indicated snowmobiles 

had damaged between 12 and 720 trees per acre (WWA 2009). Damage to vegetation has been 

observed in the Greater Yellowstone Area that is caused by winter recreational activities that occur 

off trail. For example, branches of willows (Salix spp.) and sagebrush (Artemisia spp.) have been 

broken, and leaders have been removed from conifers (Stangl 1999). Neumann and Merriam (1972) 

found that rigid woody stems up to 1 inch in diameter were very susceptible to damage. Stems were 

snapped off in surface packed or crusted snow. Neumann and Merriam (1972) also observed that 

compacted snow conditions caused twigs and branches to bend sharply and break. Stems that were 

more pliable bent and sprang back although the snowmobile track often removed bark from the 

stems’ upper surfaces. Sub-zero temperatures make stems more prone to snapping rather than 

bending. Direct mechanical effects by snowmobiles on vegetation at and above snow surface can be 

severe. After only a single pass by a snowmobile, more than 78 percent of the saplings on a trail were 

damaged, and nearly 27 percent of them were damaged seriously enough to cause a high probability 

of death (Neumann and Merriam 1972). Young conifers were found to be extremely susceptible to 

damage from snowmobiles. Broken stems of any woody species would provide places for pathogens 

to enter the plant tissues and would reduce the integrity of developing stems or trunks, both of which 

could lead to additional damage or death of individuals. These direct effects are expected to be 

localized and not result in loss of entire occurrences.

On the Tahoe National Forest, OSV use may directly damage individuals of the Tahoe National 

Forest special interest plants Arctostaphylos mewukka ssp. truei, and Arctostaphylos nissenana.

Indirect Effects

Airborne pollutants from OSVs would be concentrated in high-use areas. Because deciduous trees 

and shrubs lose their leaves in the winter months, they cannot photosynthesize during fall and winter. 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

323

Thus, respiration is dramatically reduced for deciduous trees and shrubs. Although evergreen trees 

and shrubs retain their leaves and are thus capable of photosynthesis and respiration during winter, 

these processes are also considerably reduced during the cold season. Reduced respiration during the 

winter means that smaller amounts of the airborne pollutants would be ingested through gas 

exchange. 

Pollutants which are trapped and then released during snowmelt may (or may not) have some 

adverse and some beneficial effects, however the extent and bearing of specific effects is unknown. 

It is expected that pollutant concentrations would be low enough that water quality would not be 

impaired (McNamara 2016), and thus it is likely that plant responses, if any, would not be noticeable.

Perennial herbaceous species (including bryophytes)

Direct Effects

With the requirement of adequate snow to avoid resource damage or minimum snow depths

providing protection of the soil surface and ground vegetation, perennial herbaceous species (which 

die back each year to buds at or below the soil surface) would not be directly affected by current or 

proposed OSV uses.

Indirect Effects

Snow compaction from dispersed OSV use is not expected to affect perennial herbaceous species 

because the possible delayed snowmelt (usually a week or two) and small degree of colder soil 

temperatures in the compacted snow areas would be within the normal range of variation that they 

experience on the Tahoe National Forest.. Where it occurs each year, compacted snow may alter the 

timing of new foliage emergence in the spring due to delayed snowmelt and colder soil temperatures, 

but perennial herbaceous plants in the Sierra Nevada are assumed to be adapted to a wide variety of 

natural snowmelt times and the effects of compacted snow would likely be masked by the annual 

variation in snowpack. 

Pollutants from dispersed OSV use (both airborne and those small amounts that become entrapped in 

the snow) would also not likely affect perennial herbaceous species because living plant tissues are 

not present above ground during the winter and pollutants are not expected to accumulate within the 

snow column or in run-off at high enough concentrations to cause noticeable damage.

Where occurrences exist in high-use areas, compaction and pollutants may be concentrated enough 

to cause some small magnitude changes to plant growth and community interactions. No populations 

are expected to decline with any of the proposed OSV uses.

Annual plant species

Direct Effects

Plant species that complete their life cycle within one growing season would not be directly affected 

by current or proposed OSV uses because they are not growing when authorized OSV uses may 

occur.

Indirect Effects

Snow compaction from dispersed OSV use is not expected to affect annual species because the 

possible delayed snowmelt (usually a week or two) and small degree of colder soil temperatures in 

the compacted snow areas would be within the normal range of variation. Compacted snow may 
Over-snow Vehicle Use Designation

Tahoe National Forest

324

slightly alter the timing of seed germination and plant growth in the spring, due to delayed snowmelt 

and colder soil temperatures in the compacted areas. This is not expected to noticeable affect annual 

plants because they are assumed to be adapted to a wide variety of natural snowmelt times within 

their ranges of distribution. The annual variation in snowpack and temperatures would likely mask 

any differences in phenology due to OSV uses.

Pollutants from dispersed OSV use (both airborne and those small amounts that become entrapped in 

the snow) would also not likely affect annual species because living plant tissues are not present 

above ground during the winter and pollutants are not expected to accumulate within the snow 

column or in run-off at high enough concentrations to cause any noticeable changes.

Where occurrences exist in high-use areas, compaction and pollutants may be concentrated enough 

to cause some small magnitude changes to plant community interactions. No populations are 

expected to decline with any of the proposed OSV uses.

Aquatic Species

Direct Effects

Aquatic plant species would not be directly affected by current or proposed OSV uses because OSVs 

are not authorized to operate over or within aquatic habitats.

Indirect Effects

Delayed snowmelt and transfer of sub-freezing temperatures from snow compaction is not expected 

to affect aquatic plant species. 

Airborne pollutants would not affect aquatic species because the plants grow underwater. In 

dispersed open areas, pollutants are not expected to accumulate within the snow column or in run-off 

at high enough concentrations to cause any noticeable changes to vegetation. Where occurrences 

exist in high-use areas, pollutants may be concentrated enough to cause some small magnitude 

changes to plant community interactions. No populations are expected to decline with any of the 

proposed OSV uses.

Special Aquatic Features – Fens

Fens can be threatened by resource use affecting the watershed such as livestock grazing and 

trampling, timber harvest, road building, off-road vehicle use, water pumping, and water pollution. 

Any condition or activity that disturbs the hydrologic regime or soil temperature of a fen, causing 

drying or warming, may threaten the function of that fen (Sikes et al. 2013). 52 acres of fen habitats 

are mapped on the Tahoe National Forest.

Direct Effects

Because adequate snow to avoid resource damage or minimum snow depths would prevent direct 

disturbance of soils or ground vegetation, there would be no direct effects to fen habitats.

Indirect Effects

Snow compaction poses the greatest threat from the proposed OSV uses. Delayed snowmelt and 

colder temperatures under compacted snow may cause changes to fen communities. The effects vary 

with differing usage patterns. A single snowmobile pass is far less likely to significantly affect 

hydrologic or ecological processes in wetlands than a series of intensely-used snowmobile trails

(Gage and Cooper 2009). Effects are much more likely to occur where fens are present near 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

325

designated OSV trails, and would be more dispersed in areas open to cross-country travel. Possible 

changes to the fen communities could include shifts in species composition due to colder 

temperatures and disruption of the insulating space that naturally develops beneath the snow. In order 

for species composition to change as a result of snow compaction, the same specific areas would 

need to be compacted year after year, and the likelihood of this occurring is much greater where 

OSV use is concentrated, such as along the designated OSV trails. Because so many site-specific 

variables are involved, compositional changes due to snow compaction are not possible to predict. 

Where fen habitats exist within high-use areas, some compositional changes could result from snow 

compaction, but these are expected to be minor and not impair the function of the fen habitat.

Airborne pollutants would not affect fens because these communities would be under a blanket of 

snow when the emissions are produced. As with any of the plant groups, pollutants which are trapped 

and then later released during snowmelt may (or may not) have some adverse and some beneficial 

effects, however the extent and direction of specific effects is unknown. It is expected that pollutant 

concentrations would be low enough that water quality would not be impaired, and thus it is likely 

that fen responses, if any, would not be noticeable.

Invasive Species

On the Tahoe National Forest, 19 invasive plant species are documented. The Botany Specialist 

Report, Appendix B, includes a list of each species and their acreage of mapped infestations in highuse areas and in areas designated for OSV use. Six additional invasive plant species are likely 

present (Bromus tectorum, Berteroa incana, Hydrilla verticillata, Myriophyllum spicatum, Phalaris 

arundinacea, and Rubus armeniacus), but mapped locations are not available.

Although seed dispersal by vehicles is a major vector for weed invasions (Ouren et al. 2007, Von der 

Lippe and Kowarik 2007, Taylor et al. 2011), no literature or observational evidence was found to 

support the idea that invasive plants are spread by OSV use or grooming activities. However, it is 

possible that some weed introduction or expansion could result from these uses. OSVs could bring 

weed seeds into the project area, especially if the OSVs and/or their trailers are stored outside near 

weed infestations. Throughout the seasons of non-use (spring, summer, and fall), weed species are 

actively growing and producing seed, which may get deposited on OSVs and trailers that are stored 

outside, particularly during windy conditions or if weeds are growing in close proximity. Weed 

introductions are most likely to occur at trailheads, where seeds may be brought into the area on 

trailers, towing vehicles, and OSVs. The movement and jarring of this equipment during unloading 

may dislodge soil and other debris containing weed seeds. Less likely, but still possible, is that weed 

seeds may be deposited by the OSVs as they travel along designated trails and through areas open to 

cross-country travel, although it is unknown whether weed seeds deposited on the snow surface 

would remain viable and germinate when spring arrives. It is possible that the majority of weed seeds 

that may be brought into the area would be eaten by birds, mice, or other animals before spring 

conditions arrive.

Weeds usually gain a foothold in natural communities where soil disturbance has provided suitable 

conditions for weed seed germination, where ground vegetation is disturbed and unable to 

outcompete the invaders, and (in forested areas) where tree canopy removal or thinning has allowed 

additional sunlight to reach the forest floor. Aside from the possible introduction of weed seeds 

described above, none of the other typical factors promoting weed infestations are expected with 

OSV use.
Over-snow Vehicle Use Designation

Tahoe National Forest

326

The most likely places for possible weed introductions is in areas of concentrated OSV use. OSV 

trailheads are also accessible by wheeled vehicles during the summer seasons, so the presence of 

weeds does not necessarily indicate that they were brought to the sites as a result of OSV activities. 

Although there are some differences in designated OSV trails in each alternative, the locations and 

uses of seven OSV trailheads would be the same for all alternatives. The following weed species 

have been found at the OSV trailheads:

• Bassetts – no weeds documented

• China Wall – yellow starthistle and spotted knapweed are present 

• Cisco Grove – no weeds documented

• Little Truckee Summit - no weeds documented

• Prosser – no weeds documented

• Sand Shed/Bassetts – no weeds documented

• Yuba Pass – no weeds documented

Given the lack of evidence that OSV use contributes to weed infestations, and the low risk of the 

proposed activities, the overall risk of weed increases due to OSV use is expected to be low for all 

alternatives.

Special Interest Areas

The purpose of this SIA analysis is to determine compliance with the intended focus of Botanical 

Special Interest Areas. There is no variation between alternatives regarding OSV uses in this SIA, so 

this section will apply for all alternatives.

No cross-country OSV use would be allowed in Placer County Big Tree Grove under any of the 

alternatives. No designated OSV trails are proposed within this SIA, but one trail (Mosquito Ridge 

Trail, SNO-12E16) is adjacent to the northern boundary of Placer County Big Tree Grove, and OSV 

use is expected to remain within the designated trail corridor. No damage to the giant sequoia 

resource is anticipated. With OSV access prohibited, no direct or indirect effects are expected to 

occur to the Placer County Big Tree Grove, and OSV use would not alter any of the vegetation and 

habitat characteristics for which the SIA was established.

Cumulative Effects

Past activities are considered part of the existing condition and are discussed within the Affected 

Environment section. 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. 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 to 

those effects. 

Snow plowing at the established OSV trailheads is an ancillary activity associated with the Tahoe 

National Forest OSV Use Designation project, and is not analyzed as a part of the proposal. Snow 

plowing is not expected to affect botanical resources, other than providing an additional vector for 

the possible transport of noxious/invasive weed species. The risk of weed invasion by this means is 

relatively low in comparison with total vehicle uses throughout the year. 

Special Interest Plants

Because the current Tahoe OSV use analysis identifies likely potential effects to 13 special interest 

plants (Arctostaphylos mewukka ssp. truei, Arctostaphylos nissenana, Allium sanbornii var.

sanbornii, Carex davyi, Chlorogalum grandiflorum, Epilobium howellii, Meesia triquetra, 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

327

Pseudostellaria sierrae, Schoenoplectus subterminalis, Sphagnum species, Stachys pilosa, Rhamnus 

alnifolia, and Stuckenia filiformis), it would only be for these species that effects from other 

activities could accumulate. 

For these 13 special interest plants that may experience overlapping effects, the extent, intensity, and 

type of contributing impacts must be considered. They are currently experiencing the everyday 

stresses of life in the wild, with drought likely impacting their growth and seed production in recent 

years. Besides the threat of physical damage from many of the contributing actions, these species are 

also threatened by invasive plant encroachments. Continuing pressures on special interest plant 

habitats include wildfire, early or late freezing, severe wind or winter storms, flooding, insect 

population fluxes, and other natural events. These events may also cause damage or death of special 

interest plant individuals or cause habitat changes.

As present and future activities take place, effects to the identified species may include damage to or 

death of individuals, through project actions and possible effects from introduced invasive species, 

increased soil erosion, and other changes to habitat characteristics. It is expected that all of these 

projects would include reasonable mitigations to minimize or reduce impacts and monitor for 

concerns to help manage impacts to Tahoe National Forest special interest plant species habitat and 

occurrences. Mitigations to reduce the risk of spreading weeds are required for all the contributing 

actions considered, thereby making these impacts less likely to occur. If impacts still occur, only 

low-intensity, localized effects are expected for the special interest plant species. 

The annual, seasonal timing of OSV effects does not eliminate the chance of direct and indirect 

effects accumulating. Broken branches of woody plants and any deceased individual plants would 

require one to several years to recover, and additional actions would be taking place during this 

recovery time. Individually and collectively, the magnitude of effects from these actions would 

remain relatively low. Natural disturbances, such as fire, wind and ice storms, and drought are much 

more likely to impact sensitive plant species, and their effects would be considerably greater. With 

cumulative effects considered, special interest plant species viability in the OSV project area would 

be maintained and no trend toward Federal listing would occur. When the effects from other projects 

and activities are combined where and when they overlap with the effects from the Tahoe OSV Use 

Designation Project, there would still be no loss of viability for any plant species and none would 

trend toward Federal listing, for all alternatives.

Invasive Plants

Invasive plants are also analyzed for each project, and mitigations are typically incorporated into 

project plans where ground disturbance may occur. In addition, weeds are routinely treated each year 

as part of the Tahoe National Forest weeds program. The low weed risk of this project would add 

minimal risk to the ongoing and foreseeable actions in the planning area.

Special Interest Areas

Because OSV use would not have direct or indirect effects to botanical special interest areas, there 

would be no cumulative effects from OSV use.

Alternative 1 Effects to Botanical Resources

Detailed indicators and measures for botanical resources are presented in table 104, which

summarizes the measures by major analysis topics.
Over-snow Vehicle Use Designation

Tahoe National Forest

328

Table 104. Botanical resources indicators and measures for alternative 1

Analysis Topic Total acres on Tahoe 

National Forest

Acres within high-use

areas

Acres in designated 

OSV areas

Special interest plants 3,990 1,052 3,632

Fens, bogs 52 12 52

Invasive plants 1,440 14 759

Special interest areas 357 0 0

No additional types of effects to botanical resources beyond those described in Effects Common to 

All Alternatives are specific to alternative 1. This alternative would generally have greater potential 

for effects to these botanical resources due to larger areas of open OSV use.

Alternative 1 has no minimum snow depth requirement for OSV use, but riders still must not damage 

the underlying soil and vegetation resources because causing resource damage is illegal. It is 

assumed that a minimum of 12 inches of snow is typically needed to avoid damaging resources, and 

on trails with underlying roads, a minimum of 6 inches is typically needed to avoid damage to the 

underlying road surface. These are essentially the same requirements for snow depth as alternative 2,

and would provide a reasonable protection for non-woody TEPS plants.

Special Interest Plants

Special interest plant species in the various plant life form categories would be affected differently, 

as described above in Effects Common to All Alternatives. Trees, shrubs, and sub-shrubs (woody 

plants) may be directly damaged by OSVs where they occur in areas designated for OSV use, and 

they may also experience indirect effects from snow compaction and pollutants, most likely to be 

noticeable where they occur near designated OSV trails. Perennial herbaceous species, annual 

species and aquatic species would not be directly affected, but they too may also experience 

noticeable indirect effects if they occur near designated OSV trails.

Indirect effects from snow compaction are expected to be greater with alternatives 1, 2, and 4 

because only a minimal protection is afforded to ground vegetation. Alternative 1 provides minimal 

protection for woody sensitive plants because, although a minimum snow depth is not identified, 

enforcement of a reasonable avoidance of resource damage is the management tool used to keep 

OSV use from occurring when snow depths are too low. 

Because direct damage can happen where they occur in areas designated for OSV use and indirect 

effects to occurrences within high-use areas, three of the five special interest woody plant species

considered, Arctostaphylos mewukka ssp. truei, Arctostaphylos nissenana, and Rhamnus alnifolia, 

may be affected by alternative 1 of the Tahoe OSV Use Designation project, but the possible effects 

would not contribute to a downward trend or the species being added to the Regional Forester’s 

Sensitive Plant List.

Because there could be indirect effects to occurrences within high-use areas, seven of the special 

interest perennial herbaceous plant species (Carex davyi, Epilobium howellii, Meesia triquetra, 

Pseudostellaria sierrae, Sphagnum species, Stachys pilosa, and Stellaria obtusa) and one of the 

special interest aquatic plant species (Stuckenia filiformis) may be affected by alternative 1 of the 

Tahoe OSV Use Designation project, but the possible effects would not contribute to a downward 

trend or the species being added to the Regional Forester’s Sensitive Plant List.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

329

For all other special interest plants not specifically mentioned above, because they are not known to 

be present within high-use areas, alternative 1 of the Tahoe OSV Use Designation project will not 

affect these species.

Special Aquatic Features – Fens

Because some fens are present within high-use areas, alternative 1 could result in some minor 

changes in plant community interactions due to indirect effects of snow compaction and/or OSVgenerated pollutants. Twelve of the total 52 acres of mapped fen habitats may be affected, but the 

function of the fens is not expected to be impaired.

Invasive Species

As described above in Effects Common to All Alternatives, the risk of weed introduction and/or 

spread due to OSV use is very low.

Special Interest Areas

With OSV access prohibited, no direct or indirect effects are expected to occur to the Placer County 

Big Tree Grove, and OSV use would not alter any of the vegetation and habitat characteristics for 

which the SIA was established.

Alternative 2 Effects to Botanical Resources

Detailed indicators and measures for botanical resources are presented in table 105, which

summarizes the measures by major analysis topics.

Table 105. Botanical resources indicators and measures for alternative 2

Analysis Topic Total acres on Tahoe 

National Forest

Acres within highuse areasAcres in designated 

OSV areas

Special interest plants 3,990 1,121 3,015

Fens, bogs 52 12 51

Invasive plants 1,440 59 450

Special interest areas 357 0 0

No additional types of effects to botanical resources beyond those described in Effects Common to 

All Alternatives are specific to alternative 2. 

In comparison with other alternatives, alternative 2 would be relatively equal with alternatives 1 and 

4 in providing the minimum snow depth needed to prevent damage to resources (assumed to be 

12 inches). In contrast, alternatives 3 and 5 would increase minimum snow depths to 18 inches and 

24 inches, respectively, and would provide additional degrees of protection and assurance that soil 

and vegetation resources are not damaged.

Special Interest Plants

Direct effects to special interest plant species in the various plant life form categories would be 

affected differently, as described above in Effects Common to All Alternatives. Trees, shrubs, and 

sub-shrubs (woody plants) may be directly damaged by OSVs where they occur in areas designated 

for OSV use, and they may also experience indirect effects from snow compaction and pollutants, 

most likely to be noticeable where they occur near designated OSV trails. Perennial herbaceous 
Over-snow Vehicle Use Designation

Tahoe National Forest

330

species, annual species and aquatic species would not be directly affected, but they too may also 

experience noticeable indirect effects if they occur near designated OSV trails.

With alternative 2, OSV use would not be allowed when resource damage (including damage to soil 

and ground vegetation) is likely to occur. The proposed action states that a minimum of 12 inches of 

snow is typically needed to avoid damaging resources, and on trails with underlying roads, a 

minimum of 6 inches is typically needed to avoid damage to the underlying road surface. 

Enforcement in low-snow conditions would be at the discretion of the law enforcement officer on 

site, and the interpretation of resource damage is expected to consider mainly damage to soil and 

ground vegetation. This level of resource protection is expected to prevent direct effects to nonwoody special interest plants. 

Indirect effects from snow compaction are expected to be greater with alternatives 1, 2, and 4 

because only a minimal protection is afforded to ground vegetation. Alternative 2 provides minimal 

protection for woody special interest plants because cross-country travel is allowed when there is 

adequate snow depth to avoid damage to (soil and ground vegetation) resources. However, there 

could still be considerable damage to woody species throughout the OSV season, with unintentional 

breakage and abrasion of branches and leader growth.

Because there could be direct damage where they occur in areas designated for OSV use and indirect 

effects to occurrences within high-use areas, three of the five special interest woody plant species

considered, Arctostaphylos mewukka ssp. truei, Arctostaphylos nissenana, and Rhamnus alnifolia, 

may be affected by alternative 2 of the Tahoe OSV Use Designation project, but the possible effects 

would not contribute to a downward trend or the species being added to the Regional Forester’s 

Sensitive Plant List.

Because there could be indirect effects to occurrences within high-use areas, 10 of the special interest 

perennial herbaceous plant species (Allium sanbornii var. sanbornii, Carex davyi, Chlorogalum 

grandiflorum, Epilobium howellii, Meesia triquetra, Pseudostellaria sierrae, Schoenoplectus 

subterminalis, Sphagnum species, Stachys pilosa, and Stellaria obtusa) and one of the special 

interest aquatic plant species (Stuckenia filiformis) may be affected by alternative 2 of the Tahoe

OSV Use Designation project, but the possible effects would not contribute to a downward trend or 

the species being added to the Regional Forester’s Sensitive Plant List.

For all other special interest plants not specifically mentioned above, because they are not present 

within high-use areas, alternative 2 of the Tahoe OSV Use Designation project would not affect

these species.

Special Aquatic Features – Fens

Same as alternative 1.

Invasive Species

As described above in Effects Common to All Alternatives, the risk of weed introduction and/or 

spread due to OSV use is very low.

Special Interest Areas

Same as alternative 1.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

331

Alternative 3 Effects to Botanical Resources

Detailed indicators and measures for botanical resources are presented in table 106, which

summarizes the measures by major analysis topics.

Table 106. Botanical resources indicators and measures for alternative 3

Analysis Topic Total acres on Tahoe 

National Forest

Acres within high-use

areas

Acres in designated 

OSV areas

Special interest plants 3,990 757 2,382

Fens, bogs 52 12 41

Invasive plants 1,440 107 180

Special interest areas 357 0 0

There are no additional types of effects to botanical resources beyond those described in Effects

Common to All Alternatives that are specific to alternative 3. 

In comparison with alternatives 1, 2, and 4, because of its 18 inch minimum snow depth, alternative 

3 would provide a low to moderate degree of additional protection and assurance that soil and 

vegetation resources are not damaged. However, alternative 5 would increase minimum snow depths 

to 24 inches and would provide further protection of resources.

Special Interest Plants

Special Interest plant species in the various plant life form categories would be affected differently, 

as described above in Effects Common to All Alternatives. Trees, shrubs, and sub-shrubs (woody 

plants) may be directly damaged by OSVs where they occur in areas designated for OSV use, and 

they may also experience indirect effects from snow compaction and pollutants, most likely to be 

noticeable where they occur near designated OSV trails. Perennial herbaceous species, annual 

species and aquatic species would not be directly affected, but they too may also experience 

noticeable indirect effects if they occur near designated OSV trails.

In comparison with alternatives 1, 2, and 4, increasing minimum snow depths to 18 inches for crosscountry travel would add an extra measure of protection for Special Interest plants, but effects 

already described would still be possible.

Alternative 3 provides a moderate level of protection for all Special Interest plants because an 

additional 6 inches of snow is required for OSV use, providing a deeper cushion to absorb snow 

compaction and further protection from direct effects to the shortest woody plant species. Nonwoody Sensitive plants are not expected to be directly affected. However, there could still be damage 

to woody species throughout the OSV season, with unintentional breakage and abrasion of branches 

and leader growth. 

Because alternative 3 would allow cross-country OSV travel in the least area (275,972 acres), it 

would impact the fewest special interest plant occurrences.

Because there could be direct damage where they occur in areas designated for OSV use and indirect 

effects to occurrences within high-use areas, three of the five special interest woody plant species

considered (Arctostaphylos mewukka ssp. truei, Arctostaphylos nissenana, and Rhamnus alnifolia)

may be affected by alternative 3 of the Tahoe OSV Use Designation project, but the possible effects 
Over-snow Vehicle Use Designation

Tahoe National Forest

332

would not contribute to a downward trend or the species being added to the Regional Forester’s 

Sensitive Plant List.

Because there could beindirect effects to occurrences within high-use areas, seven of the special 

interest perennial herbaceous plant species (Carex davyi, Epilobium howellii, Meesia triquetra, 

Pseudostellaria sierrae, Sphagnum species, Stachys pilosa, and Stellaria obtusa) and one of the 

Special Interest aquatic plant species (Stuckenia filiformis) may be affected by alternative 3 of the 

Tahoe OSV Use Designation project, but the possible effects would not contribute to a downward 

trend or the species being added to the Regional Forester’s Sensitive Plant List.

For all other special interest plants not specifically mentioned above, because they are not known to 

be present within high-use areas, alternative 3 of the Tahoe OSV Use Designation project will not 

affect these species.

Special Aquatic Features – Fens

Because some fens are present within high-use areas, alternative 3 could result in some minor 

changes in plant community interactions due to indirect effects of snow compaction and/or OSVgenerated pollutants. Twelve of the total 52 acres of mapped fen habitats may be affected, but the 

function of the fens is not expected to be impaired.

Invasive Species

As described above in Effects Common to All Alternatives, the risk of weed introduction and/or 

spread due to OSV use is very low.

Special Interest Areas

With OSV access prohibited, no direct or indirect effects are expected to occur to the Placer County 

Big Tree Grove, and OSV use would not alter any of the vegetation and habitat characteristics for 

which the SIA was established.

Alternative 4 Effects to Botanical Resources

Detailed indicators and measures for botanical resources are presented in table 107, which

summarizes the measures by major analysis topics.

Table 107. Botanical resources indicators and measures for alternative 4

Analysis Topic Total acres on Tahoe 

National Forest

Acres within high-use

areas

Acres in designated 

OSV areas

Special interest plants 3,990 1,052 3,632

Fens, bogs 52 12 52

Invasive plants 1,440 195 759

Special interest areas 357 0 0

No additional types of effects to botanical resources beyond those described in Effects Common to 

All Alternatives are specific to alternative 4. 

With a 12-inch minimum snow depth, alternative 4 is similar to alternatives 1 and 2, providing the 

minimum snow depth needed to prevent damage to resources (assumed to be 12 inches). However, 

alternatives 3 and 5 would increase minimum snow depths to 18 inches and 24 inches, respectively, 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

333

and would provide additional degrees of protection and assurance that soil and vegetation resources 

are not damaged.

Special Interest Plants

Special interest plant species in the various plant life form categories would be affected differently, 

as described above in Effects Common to All Alternatives. Trees, shrubs, and sub-shrubs (woody 

plants) may be directly damaged by OSVs where they occur in areas designated for OSV use, and 

they may also experience indirect effects from snow compaction and pollutants, most likely to be 

noticeable where they occur near designated OSV trails. Perennial herbaceous species, annual 

species and aquatic species would not be directly affected, but they too may also experience 

noticeable indirect effects if they occur near designated OSV trails.

Alternative 4 requires a minimum of 12 inches of snow for cross-country OSV use. This is 

considered to be a minimum reasonable protection for soil and ground vegetation. A 12-inch 

minimum snow depth is expected to prevent direct effects to non-woody special interest plants.

Indirect effects from snow compaction are expected to be greater with alternatives 1, 2, and 4 

because only a minimal protection is afforded to ground vegetation. Alternative 4 provides a minimal 

protection for woody sensitive plants because cross-country travel is allowed when there is just 

adequate snow depth to avoid damage to (soil and ground vegetation) resources, but there could still 

be damage to woody species throughout the OSV season, with unintentional breakage and abrasion 

of branches and leader growth.

Because alternative 4 would allow cross-country OSV use on the greatest area (641,105 acres), it 

could impact the most area of special interest plant occurrences.

Because there could be direct damage where they occur in areas designated for OSV use and indirect 

effects to occurrences within high-use areas, three of the five special interest woody plant species

considered (Arctostaphylos mewukka ssp. truei, Arctostaphylos nissenana, and Rhamnus alnifolia)

may be affected by alternative 4 of the Tahoe OSV Use Designation project, but the possible effects 

would not contribute to a downward trend or the species being added to the Regional Forester’s 

Sensitive Plant List.

Because there could be indirect effects to occurrences within high-use areas, seven of the special 

interest perennial herbaceous plant species (Carex davyi, Epilobium howellii, Meesia triquetra, 

Pseudostellaria sierrae, Sphagnum species, Stachys pilosa, and Stellaria obtusa) and one of the 

special interest aquatic plant species (Stuckenia filiformis) may be affected by alternative 4 of the 

Tahoe OSV Use Designation project, but the possible effects would not contribute to a downward 

trend or the species being added to the Regional Forester’s Sensitive Plant List.

For all other special interest plants not specifically mentioned above, because they are not known to 

be present within high-use areas, alternative 4 of the Tahoe OSV Use Designation project will not 

affect these species.

Special Aquatic Features – Fens

Same as alternative 1.
Over-snow Vehicle Use Designation

Tahoe National Forest

334

Invasive Species

As described above in Effects Common to All Alternatives, the risk of weed introduction and/or 

spread due to OSV use is very low.

Special Interest Areas

Same as alternative 1.

Alternative 5 Effects to Botanical Resources

Detailed indicators and measures for botanical resources are presented in table 108, which

summarizes the measures by major analysis topics.

Table 108. Botanical resources indicators and measures for alternative 5

Analysis Topic Total acres on Tahoe 

National Forest

Acres within highuse areasAcres in designated 

OSV areas

Special interest plants 3,990 976 2,678

Fens, bogs 52 16 39

Invasive plants 1,440 9 365

Special interest areas 357 0 0

No additional types of effects to botanical resources beyond those described in Effects Common to 

All Alternatives are specific to alternative 5. 

Special Interest Plants

Special interest plant species in the various plant life form categories would be affected differently, 

as described above in Effects Common to All Alternatives. Trees, shrubs, and sub-shrubs (woody 

plants) may be directly damaged by OSVs where they occur in areas designated for OSV use, and 

they may also experience indirect effects from snow compaction and pollutants, most likely to be 

noticeable where they occur near designated OSV trails. Perennial herbaceous species, annual 

species and aquatic species would not be directly affected, but they too may also experience 

noticeable indirect effects if they occur near designated OSV trails.

Alternative 5 provides the highest level of protection for sensitive plants in areas designated for OSV 

use because an additional 12 inches of snow is required, providing a deeper cushion to absorb snow 

compaction and further protection from direct effects to the shorter woody plant species. Non-woody 

sensitive plants are not expected to be directly affected. However, there could still be damage to 

woody species throughout the OSV season, with unintentional breakage and abrasion of branches 

and leader growth.

Because a smaller area would be open to cross-country OSV use (300,146 acres), alternative 5 would 

have less possibility for impacts to sensitive plant occurrences than other alternatives, except 

alternative 3.

Because there could be direct damage where they occur in areas designated for OSV use and indirect 

effects to occurrences within high-use areas, three of the five special interest woody plant species

considered (Arctostaphylos mewukka ssp. truei, Arctostaphylos nissenana, and Rhamnus alnifolia)

may be affected by alternative 5 of the Tahoe OSV Use Designation project, but the possible effects 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

335

would not contribute to a downward trend or the species being added to the Regional Forester’s 

Sensitive Plant List.

Because there could be indirect effects to occurrences within high-use areas, seven of the special 

interest perennial herbaceous plant species (Carex davyi, Epilobium howellii, Meesia triquetra, 

Pseudostellaria sierrae, Sphagnum species, Stachys pilosa, and Stellaria obtusa) and one of the 

special interest aquatic plant species (Stuckenia filiformis) may be affected by alternative 5 of the 

Tahoe OSV Use Designation project, but the possible effects would not contribute to a downward 

trend or the species being added to the Regional Forester’s Sensitive Plant List.

For all other special interest plants not specifically mentioned above, because they are not known to 

be present within high-use areas, alternative 5 of the Tahoe OSV Use Designation project will not 

affect these species.

Special Aquatic Features – Fens

Because some fens are present within high-use areas, alternative 5 could result in some minor 

changes in plant community interactions due to indirect effects of snow compaction and/or OSVgenerated pollutants. Sixteen of the total fifty-two acres of mapped fen habitats may be affected, but 

the function of the fens is not expected to be impaired.

Invasive Species

As described above in Effects Common to All Alternatives, the risk of weed introduction and/or 

spread due to OSV use is very low.

Special Interest Areas

Same as alternative 1.
Over-snow Vehicle Use Designation

Tahoe National Forest

336

Summary of Effects

Summary of Botanical Resource Measures and Determinations

Table 109. Botanical resources summary of measures for all alternatives

Analysis Topic Total acres on Tahoe 

National Forest

Acres within highuse areasAcres in designated 

OSV areas

Special interest plants

3,990

1,052 Alt. 1

1,121 Alt. 2

757 Alt. 3

1,052 Alt. 4

976 Alt. 5

3,632 Alt. 1

3,015 Alt. 2

2,382 Alt. 3

3,632 Alt. 4

2,678 Alt. 5

Special aquatic features 

- fens

52

12 Alt. 1

12 Alt. 2

12 Alt. 3

12 Alt. 4

16 Alt. 5

52 Alt. 1

51 Alt. 2

41 Alt. 3

52 Alt. 4

39 Alt. 5

Invasive plants

1,440

14 Alt. 1

59 Alt. 2

107 Alt. 3

195 Alt. 4

9 Alt. 5

759 Alt. 1

450 Alt. 2

180 Alt. 3

759 Alt. 4

365 Alt. 5

Special interest areas 357 0 all alternatives 0 all alternatives

Special Interest Plants

Special interest woody plant species may be directly affected by crushing, breaking, or abrasion of 

stems and evergreen foliage where they occur in any areas designated for OSV use. Plants of other 

life form categories would not be directly affected because their living tissues are not present above 

ground, and would not be directly damaged by OSVs. Any of the special interest plants may be 

indirectly affected by snow compaction and/or OSV emissions containing pollutants where they 

occur in close proximity to areas of high-use (within one-half mile of designated OSV trails). Thus, 

these plant species are reasonably at risk to some level of effects, dependent on their life forms, 

timing of growth, and proximity to heavy OSV use. Potential indirect effects are expected to be 

minor, and all effects would be minimized by the required minimum snow depths proposed. 

Although some individuals may be damaged or lost, OSV use is not expected to result in a trend 

toward Federal listing or loss of viability for any Special Interest plants.

Special Interest Plant Determinations:

Because there could be direct damage where they occur in areas designated for OSV use and indirect 

effects to occurrences within high-use areas, three of the five special interest woody plant species

considered (Arctostaphylos mewukka ssp. truei, Arctostaphylos nissenana, and Rhamnus alnifolia)

may be affected by all alternatives of the Tahoe OSV Use Designation project, but the possible 

effects would not contribute to a downward trend or the species being added to the Regional 

Forester’s Sensitive Plant List.

Because there could be indirect effects to occurrences within high-use areas, seven of the special 

interest perennial herbaceous plant species (Carex davyi, Epilobium howellii, Meesia triquetra, 

Pseudostellaria sierrae, Sphagnum species, Stachys pilosa, and Stellaria obtusa) and one of the 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

337

special interest aquatic plant species (Stuckenia filiformis) may be affected by alternatives 1, 3, 4, 

and 5 of the Tahoe OSV Use Designation project, but the possible effects would not contribute to a 

downward trend or the species being added to the Regional Forester’s Sensitive Plant List.

Because there could be indirect effects to occurrences within high-use areas, 10 of the special interest 

perennial herbaceous plant species (Allium sanbornii var. sanbornii, Carex davyi, Chlorogalum 

grandiflorum, Epilobium howellii, Meesia triquetra, Pseudostellaria sierrae, Schoenoplectus 

subterminalis, Sphagnum species, Stachys pilosa, and Stellaria obtusa) and one of the Special 

Interest aquatic plant species (Stuckenia filiformis) may be affected by alternative 2 of the Tahoe

OSV Use Designation project, but the possible effects would not contribute to a downward trend or 

the species being added to the Regional Forester’s Sensitive Plant List.

For all other special interest plants not specifically mentioned above, because they are not known to 

be present within high-use areas, all alternatives of the Tahoe OSV Use Designation project will not 

affect these species.

Special Aquatic Features – Fens

Direct effects to fens are unlikely to occur due to authorized public OSV use as proposed in any of 

the alternatives. Minor indirect effects are possible from snow compaction and/or OSV-generated 

pollutants, but fen function would not be altered.

Invasive Plants

Nineteen invasive plant species are documented in the project area, and many infestations along 

roadsides are treated each year. Weeds may be introduced to OSV trailheads and into areas 

designated for OSV use (possibly transported on trailers, towing vehicles, or OSVs), but the other 

typical factors promoting the spread and establishment of weeds (soil disturbance and vegetation 

cover reductions) are not expected to occur with the proposed OSV uses. There have been no 

observations or literature found that point to OSV use causing introduction or spread of invasive 

plants, but it may be possible, especially at trailheads, where vehicle use is concentrated. Given this 

uncertainty and the overall lack of evidence of OSV use contributing to weed infestations, the risk of 

weed increases due to OSV use is expected to be low for all alternatives.

Special Interest Areas

For all alternatives, the vegetation and habitat characteristics for which the Placer County Big Tree 

Grove was established would be maintained. The required minimum snow depths for OSV use, and a 

prohibition of OSV use within this SIA would prevent damaging effects from occurring to the giant 

sequoia resource.

Compliance with LRMP and Other Relevant Laws, Regulations, Policies and Plans 

All alternatives would maintain viable populations of all native and desired nonnative plants, and the 

proposed activities were reviewed for possible effects on special interest species, and thus, would be 

compliant with Forest Service Manual direction. In addition, noxious/invasive weeds were evaluated 

for effects from the proposed actions and suitable prevention measures taken, thus complying with 

the Tahoe National Forest LRMP and Forest Service Manual direction, as well as Executive Orders 

13112 and 13751.

Special interest areas with a botanical focus would be managed to preserve the characteristics for 

which the areas were established, and thus, would comply with the Tahoe National Forest LRMP.
Over-snow Vehicle Use Designation

Tahoe National Forest

338

Other Relevant Mandatory Disclosures

Unavoidable Adverse Effects 

As described in Effects Common to All Alternatives, special interest woody plants and other special 

interest plants in high-use areas may be affected by OSV use. Without placing restrictions in areas 

where these species occur, there could be unavoidable adverse effects to some individuals.

Irreversible and Irretrievable Commitments of Resources

Although some adverse effects to special interest plants may occur, these plants are a renewable 

resource, and thus, there would be no irreversible commitments of the resource. To a small extent,

excessive unauthorized damage to individuals could cause mortality, and thus, may constitute an 

irretrievable commitment for special interest plant species.

Socioeconomic Conditions

Relevant Laws, Regulations, and Policy

Regulatory Framework

Land and Resource Management Plan

The Tahoe LRMP identifies goals for recreation as well as the economic and social environment. In 

particular, the following goals help to frame the social and economic analysis in this report:

• “The Forest will provide a variety of opportunities for developed and dispersed recreation 

experiences.”

• “Make programs and activities of the Tahoe National Forest available to all persons regardless of 

race, color, sex, religion, or National origin.”

Additionally, the LRMP identifies standard and guidelines related to address recreation user conflict, 

which are relevant for the social analysis:

• “Separation of the users is preferable, offering both types of users a satisfying recreational 

experience.”

• Consider “safety of the users.”

Travel Management Rule Subpart C

The Forest Service’s 2005 Travel Management Rule requires the designation of roads, trails, and 

areas on national forests and grasslands that are open to motor vehicle use. Subpart C mandates the 

designation of routes and areas for over-snow vehicle use. 

Federal Law

Multiple Use and Sustained Yield Act

The Multiple Use and Sustained Yield Act requires that economic impacts are considered when 

establishing management plans or decisions that may affect the management of renewable forest and 

rangeland resources. This report meets the requirements of this law by addressing the economic 

impacts of OSV use designation on the local economy.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

339

National Environmental Policy Act

The National Environmental Policy Act (NEPA) requires that economic and social impacts of 

Federal actions be considered as part of the environmental analysis. This section includes analysis on 

social and economic issues identified during the scoping process to meet the terms of NEPA and 

regulations.

National Forest Management Act

The National Forest Management Act and regulations require that the economic impacts of decisions 

or plans affecting the management of renewable resources are analyzed and that the economic 

stability of communities whose economies are dependent on national forest lands is considered. This 

analysis meets the requirements of the National Forest Management Act by specifically considering 

the economic impacts of the implementation of the OSV use designation project and its impacts on 

local communities and minority populations.

Executive Orders

Environmental Justice, EO 12898 of February 11, 1994

Executive Order 12898 directs Federal agencies to identify and address any adverse human health 

and environmental effects of agency programs that disproportionately impact minority and lowincome populations. This ssection identifies minority and low-income populations in the analysis 

area and addresses the potential for disproportionate and adverse effects to these populations. 

Resource Indicators and Measures 

Resource indicators and measures shown in table 19 will be used to measure and disclose effects to 

socioeconomic resources related to OSV use designations and grooming trails for OSV use.

Table 110. Socioeconomic resource indicators and measures for assessing effects

Resource 

Element Resource Indicator Measure(Quantify if possible)

Economic activity Employment Number of jobs and amount of labor income

Quality of life Recreation visitation Number of recreation visits

Quality of life Values, beliefs, and attitudes Qualitative evaluation of public values, beliefs, and 

attitudes

Environmental 

Justice

Effects to low-income and 

minority populations 

Qualitative evaluation of disproportionate effects to lowincome and minority populations

Methodology 

Economic Analysis

Economic impacts were modeled using IMPLAN Professional Version 3.0 with 2014 data. IMPLAN 

is an input-output model, which estimates the economic impacts of projects, programs, policies, and 

economic changes on a region. IMPLAN analyzes the direct, indirect, and induced economic 

impacts. Direct economic impacts are generated by the activity itself, such as visitor spending 

associated with OSV use on the Tahoe National Forest. Indirect employment and labor income 

contributions occur when a sector purchases supplies and services from other industries to produce 

their product. Induced contributions are the employment and labor income generated as a result of 
Over-snow Vehicle Use Designation

Tahoe National Forest

340

spending new household income generated by direct and indirect employment. The employment 

estimated is defined as any part-time, seasonal, or full-time job. In the economic impact tables, 

direct, indirect and induced contributions are included in the estimated impacts. The IMPLAN 

database describes the economy in 536 sectors using Federal data from 2014. 

Data on use levels under each alternative were collected from Forest Service resource specialists. In 

most instances, the precise change is unknown. Therefore, the changes are based on the professional 

expertise of Forest Service resource specialists. Regional economic impacts are estimated based on 

the assumption of full implementation of each alternative. The actual changes in the economy would 

depend on individuals taking advantage of the resource-related opportunities that would be supported 

by each alternative. If market conditions or trends in resource use were not conducive to developing 

some opportunities, the economic impact would be different from what is estimated in this analysis.

Social Analysis

Social effects analysis uses the baseline social conditions presented in the Affected Environment 

section, National Visitor Use Monitoring (NVUM) profiles (USDA Forest Service 2016b), and 

public comments to discern the primary values that the Tahoe National Forest provides to area 

residents and visitors. Social effects are based on the interaction of the identified values with 

estimated changes to resource availability and uses. Key determinants of quality of life that may be 

affected by OSV route and area designation were identified through the scoping process.

Information Sources 

Key data sources for the social and economic analysis include:

• Economic Profile System (EPS), Headwaters Economics

• U.S. Census Bureau, American Community Survey

• U.S. Forest Service, Ecosystem Management Coordination, National Forest Recreation 

Economic Contributions website

• National Visitor Use Monitoring program data for the Tahoe National Forest, last collected in 

FY2010

• Public scoping comments

Spatial and Temporal Context for Effects Analysis

Most of the Tahoe National Forest lands are located within Nevada, Placer, Sierra, and Yuba 

Counties. However, the geographic footprint of national forests does not always correspond with 

functional economic areas affected by forest management. Forest Service economists have defined 

economic analysis areas for all national forests and grasslands using a protocol that identifies 

interactions between Forest Service resource management and local economic activity. Based on this 

protocol, the Tahoe National Forest’s economic area of influence encompasses Butte, El Dorado, 

Lassen, Nevada, Placer, Plumas, Sacramento, Shasta, Sierra, Sutter, Trinity, and Yuba Counties. 

These 12 counties form the social and economic analysis area for this report. 

The temporal boundaries for analyzing effects to the social and economic environment extend 

10 years into the future (2026). This is the period for which social and economic consequences are 

foreseeable. Social and economic change, including changes in recreation preferences, cannot 

plausibly be predicted outside this temporal frame. 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

341

Affected Environment

Existing Condition 

Table 111. Resource indicators and measures for socioeconomic resources, existing condition

Resource 

Element

Resource Indicator

(Quantify if possible)

Measure

(Quantify if possible)

Economic activity Employment Number of jobs and amount of labor income

Quality of life Recreation visitation Number of recreation visits

Quality of life Values, beliefs, and attitudes Qualitative evaluation of public values, beliefs, and 

attitudes

Environmental 

Justice

Low-income and minority 

populations

Identification of low-income and minority populations in 

the analysis area

Demographic and Economic Characteristics

The area around the Tahoe National Forest is a mixture of metropolitan and non-metropolitan areas. 

The forest is located between two major metropolitan areas – Sacramento, California, and Reno, 

Nevada. However, much of the area immediately around the forest is rural. 

The analysis area has higher shares of older residents than the state. Nevada, Plumas, Sierra, and 

Trinity Counties have about double the share of residents over the age of 65, compared to the entire 

state of California. Older populations may have different recreational preferences. For instance, 

mobility limitations associated with age may increase the importance of easy access to recreational 

sites. 

Table 112. Demographic characteristics by county

Location

Population

(ACS 2014 5-

year Estimate)

Rural-Urban Continuum Code

(ERS 2013)

Share of Population 

Over 65

(ACS 2014 5-year 

Estimate)

Butte County 221,578 3 (Metro, less than 250,000) 16.1%

El Dorado County 181,465 1 (Metro, more than 1 million) 16.3%

Lassen County 33,356 7 (Nonmetro, not adjacent to metro) 10.9%

Nevada County 98,606 4 (Nonmetro, adjacent to metro) 21.4%

Placer County 361,518 1 (Metro, more than 1 million) 16.6%

Plumas County 19,286 7 (Nonmetro, not adjacent to metro) 23.2%

Sacramento County 1,450,277 1 (Metro, more than 1 million) 12.0%

Shasta County 178,520 3 (Metro, less than 250,000) 18.1%

Sierra County 3,019 8 (Nonmetro, completely rural) 23.1%

Sutter County 95,067 3 (Metro, less than 250,000) 13.7%

Trinity County 13,515 8 (Nonmetro, completely rural) 22.1%

Yuba County 73,059 3 (Metro, less than 250,000) 10.9%

California 38,066,920 -- 10.7%

Source: U.S. Census Bureau 2016a and USDA ERS 2013
Over-snow Vehicle Use Designation

Tahoe National Forest

342

The 12 counties in the analysis area experience a greater degree of economic insecurity than the state 

overall. Median household incomes are lower and unemployment rates are higher in most of the 

counties within the planning area compared to the state. These economic characteristics suggest that 

changes in local employment and income may be felt acutely. Tahoe National Forest recreation 

visitors spend money on lodging, food, fuel, and other goods and services in the economic analysis 

area. The designation of OSV routes and areas may affect recreation visitation and spending. As a 

result, local employment and income may change. Additionally, visitor spending contributes to 

county and municipal revenue from lodging and sales taxes. Tax revenues are used to fund essential 

public services, such as emergency management. The environmental consequences analysis 

addresses possible changes in employment, income, and public finances in the context of local 

economic characteristics.

Table 113. Economic characteristics by county

Location

Median Household 

Income

(ACS 2014 5-year 

Estimate)

Unemployment 

Rate

(ACS 2014 5-year 

Estimate)

Share of Tourism-related 

Employment

(County Business Patterns 2013, 

accessed via EPS)

Butte County $43,165 13.1% 18.6%

El Dorado County $68,507 11.3% 27.8%

Lassen County $53,351 13.4% 20.4%

Nevada County $56,949 10.7% 26.9%

Placer County $73,747 9.3% 23.0%

Plumas County $48,032 16.7% 15.4%

Sacramento County $55,615 13.1% 16.0%

Shasta County $44,556 12.2% 17.8%

Sierra County $43,107 7.0% 31.8%

Sutter County $51,527 14.0% 17.6%

Trinity County $36,862 13.0% 19.8%

Yuba County $45,470 17.3% 16.0%

California $61,489 11.0% 16.3%

Source: U.S. Census Bureau 2016a and U.S. Census Bureau 2016b 

Much of the Tahoe National Forest recreation visitor spending contributes to economic activity in 

travel and tourism-related sectors. These sectors include retail trade, passenger transportation, 

accommodation and food, and arts, entertainment, and recreation. Travel and tourism sectors account 

for a larger share of employment in the analysis area counties than in California overall. This 

suggests that the analysis area economy is reliant on tourism (including outdoor recreation).

Recreation Visitors

National Visitor Use Monitoring (NVUM) data was last collected on the Tahoe National Forest in 

fiscal year 2010. Approximately 1.8 million visits to the Tahoe National Forest occur each year 

(USDA Forest Service 2016b). Approximately 2 percent of survey respondents indicate that they 

participate in snowmobiling during their trip, with 1.7 percent reporting that snowmobiling is the 

primary purpose of their trip (USDA Forest Service 2016b). The majority of forest visitors 

(70.8 percent) traveled fewer than 100 miles to reach the site. Nearly 40 percent of visits originated 

from a single zip code (96161), which covers the city of Truckee, California (USDA Forest Service

2016b). The NVUM data does not break out visitor origin by activity type. Therefore, the analysis 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

343

assumes that OSV and non-motorized winter recreation visitors reside in the same areas as forest 

visitors overall. 

Economic Contributions

National forest recreation visitor spending support employment and income in communities that 

surround National Forest System lands. Visitor spending is influenced by both the type of trip (local 

or non-local; day or overnight) and the type of recreation activities. Snowmobilers spend more than 

most other recreation visitors (White and Stynes 2010). The NVUM survey collects data on 

“previous and planned spending of the entire recreation party within 50 miles of the interview site 

during the trip to the area” (White and Stynes 2010). This data indicates that a snowmobiler spends 

an average of $642 on a non-local overnight trip and $74 on a local day trip, compared to $366 and 

$34 for the same types of trips among participants of all recreation activities (White and Stynes 

2010). Therefore, snowmobilers spend nearly twice what an average recreation user spends on their 

trip. 

Recreation visitation (all activities and trip types) on the Tahoe National Forest supports 

approximately 807 jobs38 and $28.6 million in labor income on an average annual basis (USDA 

Forest Service 2016a). The largest contributions are to the retail trade and accommodation and food 

services sectors (USDA Forest Service 2016a). Due to the high spending of snowmobilers, changes 

to over-snow vehicle opportunities on the Tahoe National Forest could measurably affect economic 

contributions associated with national forest recreation. The environmental consequences analysis 

addresses the economic impact of over-snow vehicle route and area designations.

Values, Beliefs, and Attitudes

Values are “relatively general, yet enduring, conceptions of what is good or bad, right or wrong, 

desirable or undesirable.”

Beliefs are “judgments about what is true or false – judgments about what attributes are linked to a 

given object. Beliefs can also link actions to effects.”

Attitudes are “tendencies to react favorably or unfavorably to a situation, individual, object, or 

concept. They arise in part from a person’s values and beliefs regarding the attitude object” (Allen et 

al. 2009).

OSV designation may affect nearby residents and visitors to the Tahoe National Forest. Public 

comments received during the scoping process provide insight into the values, beliefs, and attitudes 

of stakeholders in the OSV designation process. These comments reflect diverse opinions on the 

costs and benefits of various types of winter recreation on the Tahoe National Forest. 

The contribution of OSV use to local economic activity and the possibility of restrictions tdecreasing

these economic contributions was noted during the scoping period: “Tourism and OSV recreation is 

the main source of income for the local economy in Sierra County. This income provides jobs and 

tax revenues for the County. Many in the OSV community purchase their snowmobiles, parts, 

supplies, and fuel from Tom's Snowmobile & Service in Sierra City. The OSV community supports 

 38 The economic modeling software (IMPLAN) reports jobs as average annual full-time and part-time jobs. No distinction 

is made between full-time and part-time employment, so the job calculations in this report are not full-time equivalents 

(FTEs). However, the duration of employment is used to calculate the number of jobs. Therefore, 1 full-time or part-time 

job lasting 1 year is equivalent to 2 full-time or part-time jobs lasting 6 months each. Both of these examples will be 

reported as 1 job in this analysis. 
Over-snow Vehicle Use Designation

Tahoe National Forest

344

the local restaurants and places to stay in Sierra City and Bassetts Station. Fuel is purchased at 

Bassetts. Without this winter revenue, these fragile businesses may collapse, thus causing a hardship 

on the summer visitors and the local economy” (letter 174, comment 10). However, other 

commenters noted that OSV use may crowd out visitor spending by non-motorized winter recreation 

users: “If there is too much noise from snowmobiles, I will look for other recreational destinations, 

taking my vacation money used to support many small businesses near Tahoe National Forest 

elsewhere” (letter 176, comment 2). 

Another commenter noted the importance of motorized recreation opportunities to individuals with 

limited mobility: “I am a retired law enforcement officer who enjoys being able to access wilderness 

areas in the winter. However, I am also disabled, which prevents me from doing so unless I have 

motorized access. I can no longer ski or snowshoe into these areas to enjoy them. Please don't lock 

me out of these wilderness areas to satisfy anti-motorized sports groups with an agenda. I have just 

as much right to access these public lands as they do” (letter 17, comment 1). 

Some commenters noted that motorized and non-motorized recreationists face asymmetrical user 

conflict: “The newer snowmobiles of today are capable of high-speed travel, and encourage riders to 

“high mark. The snowmobilers' very goal is to get to a pristine bowl and leave their machines' tracks 

as high up in the bowl as possible. I have personally been on the north bowl of Castle Peak and 

watched two machines high mark the bowl repeatedly, and in less than one hour, completely 

obliterate the bowl for skiers. After a fresh snowfall, these bowls normally provide weeks of 

backcountry recreation for skiers and boarders, but a couple of machines can ruin it in the first hour 

of the day, leaving behind a slope obliterated by two-foot trenches that are difficult or impossible to 

ski through” (letter 149, comment 1).

In contrast, many OSV users believe that “the groomed trails that the skiers and other Nordic sport 

enthusiasts use are groomed exclusively by OSV users. They also provide faster and easier access for 

local search and rescue” (letter 197, comment 4). Furthermore, one commenter argues that “the 

‘conflict of uses’ issue has generally been created and emphasized by anti-OSV advocates who are 

looking for any opportunity to restrict or eliminate OSV use. Despite their aggressive litigation 

efforts, there are few, if any, court decisions that have forced an agency to restrict any motorized 

recreation based on alleged ‘conflict.’ There are many strategies that can be employed to manage the 

ever-growing human population that desires to recreate in the National Forest System. We generally 

support the concept of ‘shared use.’ As long as overall visitation numbers are appropriate for the 

affected resources, motorized and non-motorized users can be compatible with one another so long 

as individual users understand designations and plan their activities accordingly” (letter 150, 

comment 14). 

Additionally, some commenters believe that motorized and non-motorized winter recreation users 

have unbalanced opportunities on the Tahoe National Forest. For example, one comment noted that 

“From Yuba Pass south plus from the Little Truckee Summit west, there is again vast lands that are 

open to motorized winter use. This includes many miles of groomed snowmobile trails. In contract, 

between Highway 80 and Highway 49, the only non-motorized winter area is the Castle Valley and 

Round Valley area north of Donner Summit. On a fair-weather Saturday or Sunday, 300 skiers and 

snowshoers venture into this area. That is a huge number of users for such a small area. It is also an 

unwarranted situation given that expansion of this non-motorized area to the west side of Andesite 

Peak would not significantly reduce snowmobile opportunities given the lands from Yuba Pass south 

plus from Little Truckee Summit west” (letter 212, comment 5).

In contrast, some OSV users believe that “there is an immense amount of terrain west, south and east 

of the lake that is easily accessible for skiers that want to get away from the noise or smell. I have 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

345

been to many of these without the sled. Once areas are closed, they are never re-opened to sleds. So 

we lose more and more terrain as these proposals come through. The area proposed by a commenter 

online of Castle Peak is a prime example. There has already been a designated no sled area in this 

area due to prior agreements. That is a great sled skiing area and we see plenty of skiers that enjoy it 

simultaneously when we are out there. The argument of being close to the trail head goes for us too. 

If I want to get a few runs in before work on my sled, I can't head 20 miles back into the wilderness, 

I need something close by” (letter 158, comment 3).

Snow depth restrictions were controversial among some commenters with one noting that “setting a 

specific depth is dangerous and will lead to area closure based on a single measurement, more 

negative interactions between snowmobiles and skiers and a level of mistrust between the FS and 

recreation groups” (letter 222, comment 4) and that restrictions are unnecessary because 

“snowmobile riders won't ruin their OSVs on bare ground” (letter 60, comment 2). Another 

commenter was concerned that proposed snow depth restrictions were inadequate, arguing that 

“Limiting off trail OSV use to areas covered by at least 12" of snow does little to protect the natural 

environment. A minimum of 30" of snow depth would be a more reasonable standard. Many times, 

12" of snow is not sufficient to prevent a 130 pound skier from disturbing buried vegetation. OSVs 

obviously penetrate much more deeply through the snow surface” (letter 72, comment 2). 

Some commenters are also concerned about the environmental implications of OSV use on the Tahoe 

National Forest, arguing that pollution and noise due to OSV use can harm drinking water quality 

(letter 183, comment 55) and affect wildlife habitat (letter 147, comment 32). 

The relationship between OSV users and Pacific Crest Trail users was highlighted in several 

comments. For some, OSV use near the Pacific Crest Trail disturbs skiers and other non-motorized 

winter recreation users (letter 39, comment 1). Other commenters, however, argued that “The Pacific 

Crest Trail Association's request for 1/2 mile wide corridor on the PCT is ludicrous and should be 

disregarded by the Forest Service” (letter 172, comment 3) and that limiting PCT crossing is 

“impractical and senseless” (letter 95, comment 6). 

Environmental Justice

In 1994, President Clinton issued Executive Order 12898. This order directs Federal agencies to 

focus attention on the human health and environmental conditions in minority and low-income 

communities. The purpose of EO 12898 is to identify and address, as appropriate, disproportionately 

high and adverse human health or environmental effects on minority and low-income populations.

Environmental justice is the fair treatment and meaningful involvement of people of all races, 

cultures, and incomes, with respect to the development, implementation, and enforcement of 

environmental laws, regulations, and policies. The goal of environmental justice is for Federal 

agency decision-makers to identify impacts that are disproportionately high and adverse with respect 

to minority and low-income populations and identify alternatives that will avoid or mitigate those 

impacts. According to USDA DR5600-002 (USDA Forest Service 1997), environmental justice, 

minority, minority population, low-income, and human health and environmental effects, are defined 

as follows:

Environmental Justice means that, to the greatest extent practicable and permitted by law, all 

populations are provided the opportunity to comment before decisions are rendered on, are 

allowed to share in the benefits of, are not excluded from, and are not affected in a 

disproportionately high and adverse manner by, government programs and activities affecting 

human health or the environment.
Over-snow Vehicle Use Designation

Tahoe National Forest

346

Minority means a person who is a member of the following population groups: American 

Indian or Alaskan Native; Asian or Pacific Islander; Black, not of Hispanic origin; or Hispanic.

Minority Population means any readily identifiable group of minority persons who live in 

geographic proximity to, and, if circumstances warrant, migrant farm workers and other 

geographically dispersed/transient persons who will be similarly affected by USDA programs or 

activities.

Low-income Population means any readily identifiable group of low-income persons who live 

in geographic proximity to, and, if circumstances warrant, migrant farm workers and other 

geographically dispersed/transient persons who will be similarly affected by USDA programs or 

activities. Low-income populations may be identified using data collected, maintained and 

analyzed by an agency or from analytical tools such as the annual statistical poverty thresholds 

from the Bureau of the Census' Current Population Reports, Series P-60 on Income and Poverty.

Human Health and/or Environmental Effects as used in this Departmental Regulation 

include interrelated social and economic effects.

The emphasis of environmental justice is on health effects and/or the benefits of a healthy 

environment. The Council on Environmental Quality (CEQ) has interpreted health effects with a 

broad definition: “Such effects may include ecological, cultural, human health, economic or social 

impacts on minority communities, low-income communities or Indian Tribes...when those impacts 

are interrelated to impacts on the natural or physical environment” (CEQ 1997).

As noted above, residents of the analysis area counties typically have lower median household 

incomes and higher rates of unemployment than California residents overall. Poverty rates vary 

substantially within the planning area. Some counties, such as El Dorado, Nevada, and Placer have 

much lower rates of poverty than the state overall. In contrast, more than one-fifth of Butte and Yuba 

County residents live in poverty. These data suggest that the planning area contains an environmental 

justice population based on poverty status. 

However, the analysis area counties have lower shares of minority residents than the state. In 

California, about 60 percent of the population identifies as a racial or ethnic minority (other than 

white, non-Hispanic). In the analysis area counties, the shares of minority residents are considerably 

lower, except in Sacramento and Sutter counties, where approximately half of the residents identify 

as racial or ethnic minorities. These data indicate that the planning area does not contain 

environmental justice populations based on race and ethnicity. 

Table 114. Environmental justice characteristics by county

Location Poverty Rate39

(ACS 2014 5-year Estimate)

Share Other than White Alone, Non-Hispanic

(ACS 2014 5-year Estimate)

Butte County 21.5% 25.8%

El Dorado County 10.3% 20.7%

Lassen County 17.1% 34.0%

 39 “Following the Office of Management and Budget's (OMB) Statistical Policy Directive 14, the Census Bureau uses a set 

of money income thresholds that vary by family size and composition to determine who is in poverty. If a family's total 

income is less than the family's threshold, then that family and every individual in it is considered in poverty. The official 

poverty thresholds do not vary geographically, but they are updated for inflation using Consumer Price Index (CPI-U). The 

official poverty definition uses money income before taxes and does not include capital gains or noncash benefits (such as 

public housing, Medicaid, and food stamps)” (U.S. Census Bureau 2016a).
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

347

Location Poverty Rate39

(ACS 2014 5-year Estimate)

Share Other than White Alone, Non-Hispanic

(ACS 2014 5-year Estimate)

Nevada County 12.4% 14.0%

Placer County 8.9% 25.0%

Plumas County 15.9% 15.5%

Sacramento County 18.1% 52.7%

Shasta County 18.0% 19.5%

Sierra County 16.3% 12.7%

Sutter County 16.8% 51.0%

Trinity County 18.6% 16.9%

Yuba County 22.2% 42.6%

California 16.4% 60.8%

Source: U.S. Census Bureau 2016a 

Given the high rates of poverty in the analysis area, the environmental consequences analysis will 

address the possibility that management actions could disproportionately and adversely affect lowincome individuals. Low-income individuals may be less able to adapt to changes in employment, 

income, and recreation opportunities on the Tahoe National Forest.

Environmental Consequences

Alternative 1 – No Action

Economic Activity

Alternative 1 would not affect forest recreation use or visitor spending. Therefore, this alternative 

would not affect the number of jobs, amount of labor income, or tax revenue in the local economy. 

Visitor use is expected to increase over time due to factors outside the control of the Forest Service 

(e.g., population growth), which would increase employment, labor income, and tax revenue. 

However, these increases in visitor use would not be affected by the selection of any of the 

alternatives.

Quality of Life

The values, beliefs, and attitudes discussion above identified several key issues related to OSV use 

on the Tahoe National Forest and quality of life for visitors and area residents. In particular, 

commenters discussed recreation opportunities and user conflict. Alternative 1 would not implement 

management activities that affect recreation opportunities or user conflict. User conflict may increase 

as population and visitor use increase. As a number of commenters noted, user conflict is often 

asymmetrical (motorized use inhibit non-motorized use, but not the reverse). Therefore, the 

possibility of increased user conflict may affect quality of life for non-motorized winter recreation 

users. 

Environmental Justice

Alternative 1 would not affect the cost of participating in recreation activities on the forest. 

Therefore, this alternative would not disproportionately and adversely affect the low-income 

individuals and households in the analysis area. However, climate change may reduce the areas on 
Over-snow Vehicle Use Designation

Tahoe National Forest

348

the forest that are suitable for winter recreation due to reduced precipitation and warmer winters. 

This could slightly increase the travel costs (i.e., in terms of time and fuel) for accessing winter 

recreation opportunities on the forest. Low-income individuals and households have fewer financial 

resources and, thus, may be disproportionately affected by increased recreational travel costs. 

Table 115. Socioeconomic resource indicators and measures for alternative 1 

Resource 

Element

Resource Indicator

(Quantify if possible)

Measure

(Quantify if possible) (Alternative 1)

Economic 

activity

Employment, income, 

tax revenue

Number of jobs, 

amount of labor 

income, tax revenue

No change due to management; 

increased visitor use over time would 

increase number of jobs, labor 

income, and tax revenue

Quality of life Recreation visitation Number of recreation 

visits

No change due to management; 

visitor use expected to increase over 

time

Quality of life Values, beliefs, and 

attitudes

Qualitative evaluation 

of public values, 

beliefs, and attitudes

User conflict may increase due to 

population growth and increased 

visitor use

Environmental 

Justice

Low-income and 

minority populations

Change in cost of 

participating in 

recreation activities

No change due to management; 

climate change may increase 

distances winter recreation users 

must travel for adequate snow depth

Alternative 2 – Modified Proposed Action

Direct and Indirect Effects 

Economic Activity

Alternative 2 would decrease the acres designated for cross-country OSV use from 638,002 to 

406,895, a 36 percent reduction from existing conditions. However, this alternative would increase 

the miles of trail available for grooming from 217 miles under alternative 1 to 237 miles, an increase 

of 20 miles or 9 percent. Based on observational evidence, OSV visitor use is driven by the miles of 

groomed trails. However, data do not exist to quantify the relationship between the additional 

20 miles of trails available for grooming and OSV visitation. Nevertheless, alternative 2 is expected 

to increase OSV use on the Tahoe National Forest relative to the alternative 1. Current OSV users 

account for approximately 36,000 visits to the forest each year. Increased OSV visitation would 

support additional recreation-related employment, labor income, and tax revenue in the local area. 

However, as discussed in the Values, Beliefs, and Attitudes section, non-motorized winter recreation 

users may be crowded out due to OSV use. Therefore, an increase in OSV use may be offset by a 

decline in non-motorized winter use. This would lower the gains in employment, labor income, and 

tax revenue associated with increased OSV use on the Tahoe National Forest.

Quality of Life

The values, beliefs, and attitudes discussion above identified several key issues related to public 

OSV use on the Tahoe National Forest and quality of life for visitors and area residents. In particular, 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

349

commenters discussed recreation opportunities and user conflict. Alternative 2 would decrease the 

share of acres designated for cross-country OSV use relative to existing conditions. However, as 

mentioned above, this alternative would make 20 additional miles of trails available for grooming 

relative to current management. Trail grooming is expected to make the Tahoe National Forest more 

appealing for OSV recreation users. Increased OSV visitation would increase the likelihood of 

conflict between motorized and non-motorized winter recreation users. Since OSV use can make 

areas unappealing to non-motorized winter recreation users due to safety concerns and preferences 

for quiet, alternative 2 could adversely affect non-motorized winter recreation users’ quality of life.

Environmental Justice

Alternative 2 would not affect the cost of participating in recreation activities on the forest relative to 

current conditions. Therefore, this alternative would not disproportionately and adversely affect lowincome individuals and households in the analysis area. However, climate change may reduce the 

areas on the forest that are suitable for winter recreation due to reduced precipitation and warmer 

winters. This could increase the travel costs (i.e., in terms of time and fuel) for accessing winter 

recreation opportunities on the forest. Low-income individuals and households have fewer financial 

resources and, thus, may be disproportionately affected by increased recreational travel costs. 

Table 116. Socioeconomic resource indicators and measures for alternative 2 direct and indirect effects

Resource 

Element

Resource Indicator

(Quantify if possible)

Measure

(Quantify if possible)

Alternative 2

Direct/Indirect Effects

Economic 

activity

Employment, income, 

tax revenue

Number of jobs, 

amount of labor 

income, tax revenue

Increased OSV visitation would 

support additional employment, labor 

income, and tax revenue in the local 

area; possibility that reduced nonmotorized winter recreation visitation 

could offset increased economic 

activity

Quality of life Recreation visitation Number of recreation 

visits

OSV visitation expected to increase 

due to more miles of trail available for 

grooming; increased OSV visitation 

may crowd out some non-motorized 

winter recreation users

Quality of life Values, beliefs, and 

attitudes

Qualitative evaluation 

of public values, 

beliefs, and attitudes

Increased OSV visitation may 

adversely affect non-motorized winter 

recreation users’ quality of life

Environmental 

Justice

Low-income and 

minority populations

Change in cost of 

participating in 

recreation activities

No change in cost due to 

management; climate change may 

increase distances winter recreation 

users must travel for adequate snow 

depth
Over-snow Vehicle Use Designation

Tahoe National Forest

350

Cumulative Effects – Alternative 2

Past, Present, and Reasonably Foreseeable Activities Relevant to Cumulative Effects 

Analysis

Past, present, and reasonably foreseeable projects in the planning area include vegetation 

management, livestock grazing allotment management, and recreation site improvements. These 

actions may temporarily restrict or displace recreation use. However, none of the actions are 

expected to measurably affect annual recreation use, visitor spending, and associated employment, 

labor income, and tax revenue. Therefore, no cumulative effects related to economic activity are 

anticipated. The temporary displacement of recreation use may affect quality of life if preferred sites 

are temporarily unavailable. However, such effects are expected to be infrequent and minor. 

Temporary displacement is not expected to increase conflict between motorized and non-motorized 

recreation users. Finally, these past, present, and reasonably foreseeable actions may affect travel 

costs if visitors must travel farther because preferred recreation sites are temporarily unavailable. 

However, since displacement would be infrequent and minor, effects to travel costs are not expected 

to meaningfully add to the potential environmental justice effects described in the direct and indirect 

effects analysis.

Long-term, a number of ongoing and reasonably foreseeable activities are expected to improve 

opportunities for recreation visitor use on the Tahoe National Forest. The Little Truckee Summit 

Parking Area improvement project would expand parking capacity and improve facilities to better 

satisfy demand for winter recreation opportunities on the Tahoe National Forest. The Sugarplum 

project is improving recreation site conditions for winter recreation users on the Tahoe National 

Forest. The effects of ongoing and reasonably foreseeable activities related to winter recreation may 

interact with OSV use designation to affect visitation beyond what is estimated here. Trailhead 

improvements are expected to increase participation in winter motorized and non-motorized 

activities on the Tahoe National Forest. 

Table 117. Socioeconomic resource indicators and measures for alternative 2 cumulative effects

Resource 

Element

Resource Indicator

(Quantify if possible)

Measure

(Quantify if possible)

Alternative 2

Cumulative Effects

Economic 

activity

Employment, income, 

tax revenue

Number of jobs, 

amount of labor 

income, tax revenue

No measurable effects to employment, 

labor income, and tax revenue are 

expected

Quality of life Recreation visitation Number of recreation 

visits

Short-term infrequent and minor 

displacement of recreation visitors. 

Long-term increase in recreation 

visitation due to recreation site 

improvements.

Quality of life Values, beliefs, and 

attitudes

Qualitative evaluation 

of public values, 

beliefs, and attitudes

Infrequent and minor displacement not 

expected to change winter recreation 

users conflict or quality of life

Environmental 

Justice

Low-income and 

minority populations

Change in cost of 

participating in 

recreation activities

No measurable change in travel costs
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

351

Alternative 3

Direct and Indirect Effects

Economic Activity

Alternative 3 would decrease the acres designated for OSV use from 638,002 to 275,972, a 

57 percent reduction from existing conditions. However, Alternative 3 would not change the miles of 

OSV trails available for grooming relative to Alternative 1, current management (217 miles). Based 

on observational evidence, OSV visitor use is driven by the miles of groomed trails. Therefore, 

Alternative 3 is not expected to affect OSV use on the Tahoe National Forest relative to the 

Alternative 1. As a result, there would be no changes in local economic activity associated with 

recreational visitation to the Tahoe National Forest.

Quality of Life

The values, beliefs, and attitudes discussion above identified several key issues related to public 

OSV use on the Tahoe National Forest and quality of life for visitors and area residents. In particular, 

commenters discussed recreation opportunities and user conflict. Alternative 3 would substantially 

reduce the share of acres designated for cross-country OSV use relative to alternative 1. However, 

alternative 3 would not change the miles of OSV trails available for grooming. Therefore, despite the 

decrease in acres designated for cross-country OSV use, overall recreation visitation is expected to 

be consistent with current conditions on the Tahoe National Forest. In terms of winter recreation 

visitors’ quality of life, alternative 3 would have the same consequences as the alternative 1.

Environmental Justice

Alternative 3 would not affect the cost of participating in recreation activities on the forest relative to 

current conditions. Therefore, this alternative would not disproportionately nor adversely affect the 

low-income individuals and households in the analysis area. However, climate change may reduce 

the areas on the forest that are suitable for winter recreation due to reduced precipitation and warmer 

winters. This could increase the travel costs (i.e., in terms of time and fuel) for accessing winter 

recreation opportunities on the forest. Low-income individuals and households have fewer financial 

resources and, thus, may be disproportionately affected by increased recreational travel costs. 
Over-snow Vehicle Use Designation

Tahoe National Forest

352

Table 118. Socioeconomic resource indicators and measures for alternative 3 direct and indirect effects

Resource 

Element

Resource Indicator

(Quantify if possible)

Measure

(Quantify if possible)

Alternative 3

Direct/Indirect Effects

Economic 

activity

Employment, income, 

tax revenue

Number of jobs, 

amount of labor 

income, tax revenue

Potential for minor changes in 

motorized and non-motorized winter 

recreation use are not expected to 

meaningfully affect recreation-related 

employment, labor income, or tax 

revenue in local area

Quality of life Recreation visitation Number of recreation 

visits

No change due to management

Quality of life Values, beliefs, and 

attitudes

Qualitative evaluation 

of public values, 

beliefs, and attitudes

No expected effects to motorized or 

non-motorized winter recreation users’ 

quality of life

Environmental 

Justice

Low-income and 

minority populations

Change in cost of 

participating in 

recreation activities

No change in cost due to management; 

climate change may increase distances 

winter recreation users must travel for 

adequate snow depth

Cumulative Effects

The cumulative effects under alternative 3 would be similar to the cumulative effects described under 

the alternative 2. 

Alternative 4

Direct and Indirect Effects

Economic Activity

Relative to current conditions, alternative 4 would slightly increase the acres designated for crosscountry OSV use from 638,002 to 641,105, or 0.5 percent. Additionally, alternative 4 would increase 

the total miles of trails available for grooming from 217 miles under the alternative 1 to 260 miles, 

an increase of 43 miles or 20 percent. Based on observational evidence, OSV visitor use is driven by 

the miles of groomed trails. Current OSV users account for approximately 36,000 visits, out of 

1.8 million total recreation visits, to the Tahoe National Forest each year. Although OSV users 

account for a small share of total recreation visitation on the forest, Forest Service survey data 

indicate that OSV users typically spend more than other recreation users (White et al. 2013). 

As discussed in the Values, Beliefs, and Attitudes section, non-motorized winter recreation users 

typically prefer to recreate at sites without OSV users. Therefore, an increase in OSV use lead to 

reductions in non-motorized winter use. This would moderate the gains in employment, labor 

income, and tax revenue associated with increased OSV use on the Tahoe National Forest. However, 

due to the relatively high spending of OSV visitors, overall, alternative 4 is expected to support 

higher levels of employment, labor income, and tax revenue in the local area compared to all other 

considered alternatives. 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

353

Quality of Life

The effect on motorized and non-motorized winter recreation visitors’ quality of life would be the 

same as described under alternative 2. 

Environmental Justice

The environmental justice consequences of alternative 4 would be the same as those described for 

alternative 2. 

Table 119. Socioeconomic resource indicators and measures for alternative 4 direct and indirect effects

Resource 

Element

Resource Indicator

(Quantify if 

possible)

Measure

(Quantify if 

possible)

Alternative 4

Direct/Indirect Effects

Economic 

activity

Employment, income, 

tax revenue

Number of jobs, 

amount of labor 

income, tax revenue

Increased OSV visitation would support 

additional employment, labor income, and 

tax revenue in the local area; possibiity 

that reduced non-motorized winter 

recreation visitation could offset increased 

economic activity

Quality of life Recreation visitation Number of recreation 

visits

OSV visitation expected to increase due to 

more miles of trail available for grooming; 

increased OSV visitation may crowd out 

some non-motorized winter recreation 

users

Quality of life Values, beliefs, and 

attitudes

Qualitative evaluation 

of public values, 

beliefs, and attitudes

Increased OSV visitation may adversely 

affect non-motorized winter recreation 

users’ quality of life

Environmental 

Justice

Low-income and 

minority populations

Change in cost of 

participating in 

recreation activities

No change in cost due to management; 

climate change may increase distances 

winter recreation users must travel for 

adequate snow depth

Cumulative Effects

The cumulative effects under alternative 4 would be similar to the cumulative effects described under 

alternative 2. 

Alternative 5

Direct and Indirect Effects

Economic Activity

Alternative 5 would decrease the acres designated for OSV use to 300,146 acres, a 53 percent 

reduction from alternative 1. However, alternative 5 would make 215 miles of trails available for 

grooming, which is only 2 miles fewer than alternative 1. This change in miles available for 

grooming is not expected to measurably affect recreation visitation to the Tahoe National Forest. 

Therefore, OSV visitation to the Tahoe National Forest is not expected to change and employment, 

labor income, and tax revenue relative to the alternative 1.
Over-snow Vehicle Use Designation

Tahoe National Forest

354

Quality of Life

The values, beliefs, and attitudes discussion above identified several key issues related to OSV use 

on the Tahoe National Forest and quality of life for visitors and area residents. In particular, 

commenters discussed recreation opportunities and user conflict. Alternative 5 would make the 

fewest miles of trails available for grooming and would designate the second fewest acres for crosscountry OSV use. Therefore, alternative 5 would improve quality of life for non-motorized winter 

recreation users relative to the Alternative 1 and other action alternatives. The decrease in acres 

designated for cross-country OSV use may alleviate concerns expressed by non-motorized winter 

recreation users related to vehicle exhaust fumes, disparities in speed, noise, and competition for 

fresh powder. The reduction in miles of trail available for grooming and acres designated for OSV 

use on the Tahoe National Forest may adversely affect OSV users’ quality of life if they cannot 

access preferred sites, face more competition at existing sites, or need to travel further to recreate on 

the forest. However, the miles of trail available for grooming is only slightly below current 

conditions. Therefore, effects to OSV users’ quality of life are expected to be minor.

Environmental Justice

Alternative 5 would reduce opportunities for OSV recreation on the Tahoe National Forest relative to 

current conditions. Alternative 5 may require some OSV users to travel farther to recreate on the 

forest. Additionally, like all alternatives, climate change may affect travel costs due to reduced 

precipitation and warmer winters. Overall, alternative 5 is expected to increase the travel costs of 

OSV visitors to the Tahoe National Forest. Low-income individuals and families would be 

disproportionately affected by increased travel costs. 

Table 120. Socioeconomic resource indicators and measures for alternative 5 direct and indirect effects

Resource 

Element

Resource Indicator

(Quantify if possible)

Measure

(Quantify if possible)

Alternative 5

Direct/Indirect Effects

Economic 

activity

Employment, income, 

tax revenue

Number of jobs, 

amount of labor 

income, tax revenue

OSV visitation would not measurably 

change relative to current conditions, 

therefore, recreation-related 

employment, labor income, and tax 

revenue in the local area would not 

change

Quality of life Recreation visitation Number of recreation 

visits

OSV visitation is not expected to 

measurably change due to small 

change in miles of OSV trails available 

for grooming; non-motorized winter 

recreation may increase due to fewer 

acres designated for cross-country OSV 

use

Quality of life Values, beliefs, and 

attitudes

Qualitative evaluation 

of public values, 

beliefs, and attitudes

OSV users’ quality of life may decline if 

they travel farther or face site 

competition; non-motorized winter 

recreation users would benefit from 

decreased likelihood of user conflict

Environmental 

Justice

Low-income and 

minority populations

Change in cost of 

participating in 

recreation activities

OSV users would have to travel farther 

to access open areas or groomed trails; 

increased travel costs would 

disproportionately affect lower income 

individuals and families
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

355

Cumulative Effects

Past, present, and reasonably foreseeable projects may temporarily restrict or displace recreation use. 

However, none of the actions are expected to measurably affect annual recreation use, visitor 

spending, and associated employment, labor income, and tax revenue. Therefore, no cumulative 

effects related to economic activity are anticipated. The temporary displacement of recreation use 

may affect quality of life if preferred sites are temporarily unavailable. However, such effects are 

expected to be infrequent and minor. Temporary displacement is not expected to increase conflict 

between motorized and non-motorized recreation users. Finally, these past, present, and reasonably 

foreseeable actions may affect travel costs if visitors must travel farther because preferred recreation 

sites are temporarily unavailable. This effect would be the most pronounced for OSV users under 

alternative 5 because management actions would limit opportunities for OSV recreation on the 

Tahoe National Forest. Therefore, further displacement due to ongoing and reasonably foreseeable 

activities could cause further reduction in OSV opportunities and increased crowding at available 

sites.

Long-term, a number of ongoing and reasonably foreseeable activities are expected to improve 

opportunities for recreation visitor use on the forest. The Little Truckee Summit Parking Area 

improvement project would expand parking capacity and improve facilities to better satisfy demand 

for winter recreation opportunities. The Sugarplum project is improving recreation site conditions for 

winter recreation users on the forest. The interaction of these activities with the actions proposed 

under alternative 5 would affect winter recreation users’ quality of life beyond what is estimated in 

the direct and indirect effects analysis. Expanded parking capacity would lessen the possibility of 

recreation site crowding adversely affecting visitors’ quality of life.

Table 121. Socioeconomic resource indicators and measures for alternative 5 cumulative effects

Resource 

Element

Resource Indicator

(Quantify if possible)

Measure

(Quantify if possible)

Alternative 5

Cumulative Effects

Economic 

activity

Employment, income, 

tax revenue

Number of jobs, 

amount of labor 

income, tax revenue

Visitor displacement is possible, but no 

measurable effects to employment, 

labor income, and tax revenue beyond 

what is described in direct and indirect 

effects analysis

Quality of life Recreation visitation Number of recreation 

visits

Possible displacement of recreation 

visitors in the short-term; long-term site 

improvements could lessen potential 

for site competition to reduce OSV 

visitation

Quality of life Values, beliefs, and 

attitudes

Qualitative evaluation 

of public values, 

beliefs, and attitudes

Site improvements could improve 

quality of life for OSV users with fewer 

opportunities under Alternative 5

Environmental 

Justice

Low-income and 

minority populations

Change in cost of 

participating in 

recreation activities

No measurable change in travel costs
Over-snow Vehicle Use Designation

Tahoe National Forest

356

Compliance with LRMP and Other Relevant Laws, Regulations, 

Policies and Plans 

Alternative 1 would not be in compliance with Subpart C of the Travel Management rule, which 

requires designation of roads, trails, and areas on National Forest System lands to provide for OSV

use.

Alternatives 2, 3, 4, and 5 would be in compliance with Subpart C of the Travel Management rule. 

These alternatives would also be in compliance with Forest Plan goals to provide a variety of 

recreation opportunities.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

357

Summary of Environmental Effects

Table 122. Summary comparison of socioeconomic effects

Resource 

Element

Indicator/

Measure Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Economic 

activity

Employment, 

income, tax 

revenue

No change due to 

management;

increased visitor 

use over time would 

increase number of 

jobs, labor income, 

and tax revenue

Increased OSV visitation 

would support additional 

employment, labor 

income, and tax revenue 

in the local area; 

possible reduction in 

non-motorized winter 

recreation visitation 

could offset increased 

economic activity

Potential for minor 

changes in motorized 

and non-motorized 

winter recreation use 

are not expected to 

meaningfully affect 

recreation-related 

employment, labor 

income, or tax 

revenue in local area

Increased OSV visitation 

would support additional 

employment, labor 

income, and tax revenue 

in the local area; 

possible reduction in 

non-motorized winter 

recreation visitation 

could offset increased 

economic activity

OSV visitation would not 

measurably change 

relative to current 

conditions, therefore, 

recreation-related 

employment, labor income, 

and tax revenue in the 

local area would not 

change

Quality of life Recreation 

visitation 

No change due to 

management; 

visitor use expected 

to increase over 

time

OSV visitation expected 

to increase due to more 

miles of trail available for 

grooming; increased 

OSV visitation may 

crowd out some nonmotorized winter 

recreation users

No change due to 

management visitor 

use expected to

increase over time

OSV visitation expected 

to increase due to more 

miles of trail available for 

grooming; increased 

OSV visitation may 

crowd out some nonmotorized winter 

recreation users

OSV visitation is not 

expected to change due to 

small change in miles of 

OSV trails available for 

grooming; non-motorized 

winter recreation may 

increase due to fewer 

acres designated for 

cross-country OSV use

Quality of life Values, 

beliefs, and 

attitudes

User conflict may 

increase due to 

population growth 

and increased 

visitor use

Increased OSV visitation 

may adversely affect 

non-motorized winter 

recreation users’ quality 

of life

No expected effects 

to motorized or nonmotorized winter 

recreation users’ 

quality of life

Increased OSV visitation 

may adversely affect 

non-motorized winter 

recreation users’ quality 

of life

OSV users’ quality of life 

may decline if they travel 

farther or face site 

competition; nonmotorized winter 

recreation users would 

benefit from decreased 

likelihood of user conflict
Over-snow Vehicle Use Designation

Tahoe National Forest

358

Resource 

Element

Indicator/

Measure Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Environmental 

justice

Low-income 

and minority 

populations

No change due to 

management; 

climate change may 

increase distances 

winter recreation 

users must travel 

for adequate snow 

depth

No change in cost due to 

management; climate 

change may increase 

distances winter 

recreation users must 

travel for adequate snow 

depth

No change in cost 

due to management; 

climate change may 

increase distances 

winter recreation 

users must travel for 

adequate snow 

depth

No change in cost due to 

management; climate 

change may increase 

distances winter 

recreation users must 

travel for adequate snow 

depth

OSV users would have to 

travel farther to access 

open areas or groomed 

trails; increased travel 

costs would 

disproportionately affect 

lower income individuals 

and families
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

359

Cultural Resources

Relevant Laws, Regulations, and Policy

Federal Law 

National Historic Preservation Act 

The National Historic Preservation Act of 1966, as amended, directs all Federal agencies to take into 

account the effects of their undertakings (actions, financial support, and authorizations) on properties 

included in or eligible for the National Register. Implementing regulations are found at 36 CFR 800.

Land and Resource Management Plan 

The Tahoe National Forest Land and Resource Management Plan (USDA Forest Service 1990) as 

amended by the Sierra Nevada Forest Plan Amendment Supplemental Final Environmental Impact 

Statement and Record of Decision (USDA Forest Service 2004a, 2004b), provides management 

direction and standards and guidelines for vegetation, watershed, and recreation management 

activities. Forest Plan guidance relevant to heritage resources are described in more detail below. 

Section 106 of the National Historic Preservation Act of 1966 and implementing regulations requires 

the agency official to determine if the undertaking is a type of activity that could affect historic 

properties. If the nature of the undertaking has the potential to affect cultural resources, there must be 

identification efforts that may include survey. The undertaking’s area of potential effects (APE) 

would be surveyed for cultural resources in order to comply with 36 CFR 800 – Protection of 

Historic Properties, and the National Environmental Policy Act. Compliance with National Historic 

Preservation Act of 1966 and 36 CFR 800 regulations includes all historic properties be evaluated for 

the National Register of Historic Places.

Relevant Standards and Guidelines 

The Sierra Nevada Forest Plan Amendment described the following elements of managing cultural 

resources (Volume 2, Chapter 3, Part 5.8, p. 510): 

• Conducting inventories of proposed undertakings within the area of potential effects to identify 

types and locations of historic properties.

• Determining which historic properties are eligible for the National Register of Historic Places. 

• Assessing potential project effects on eligible historic properties. 

• Avoiding or mitigating adverse effects on historic properties eligible for the National Register or 

other significant sites. 

• Follow-up monitoring to assess the effectiveness of management procedures such as 

implementing site protection measures.
Over-snow Vehicle Use Designation

Tahoe National Forest

360

Region 5 Programmatic Agreement

The Tahoe National Forest has consulted with the State Historic Prexervation Officer on the 

application of this undertaking with stipulations in the Region 5 Programmatic Agreement.

40 SHPO 

concurred that requiring at least 12 inches of snow or ice (based on weather, Forest Service 

personnel and public observations), be present in order to authorize cross-country OSV use in 

designated OSV use areas would sufficiently prevent surface and subsurface impacts to historic 

properties and constitutes a finding of No Historic Properties Affected, consistent with section 7.8(b) 

of the Regional Programmatic Agreement.

Executive Orders 

Protection and Enhancement of the Cultural Environment 

The Protection and Enhancement of the Cultural Environment, EO 11593 of May 13, 1971 directs 

Federal agencies to inventory cultural resources under their jurisdiction, nominate all federally 

owned properties that meet the criteria to the National Register of Historic Places, use due caution 

until the inventory and nomination processes are completed, and assure that Federal plans and 

programs contribute to preservation and enhancement of non-federally owned properties. 

Indian Sacred Sites, EO of May 24, 1996

The Indian Sacred Sites, EO of May 24, 1996, directs Federal land management agencies, to the 

extent permitted by law, and not clearly inconsistent with essential agency functions, to 

accommodate access to and use of Indian sacred sites, to avoid affecting the physical integrity of 

such sites wherever possible, and, where appropriate, to maintain the confidentiality of sacred sites. 

Federal agencies are required to establish a process to assure that the affected Indian tribes are 

provided reasonable notice of proposed Federal actions or policies that may affect Indian Sacred 

sites.

Executive Order 13175 of November 6, 2000

In Executive Order 13175 of November 6, 2000, Section 5 states there should be a process to ensure 

meaningful and timely input in the development of regulatory policies that have tribal implications.

Executive Memorandum from April 29, 1994

In Executive Memorandum from April 29, 1994, President Clinton discusses the unique legal 

relationship between Native American Tribal governments and the U.S. Government. He requires 

each executive department and agency to consult, to assess the impact of Federal Government plans, 

and to remove impediments from consultation with tribes.

Executive Memorandum from November 5, 2009

Executive Memorandum from November 5, 2009, President Obama supports and reaffirms 

EO 13175 and gives specific directions on how plans should be developed and when they must be 

submitted to the Director of the Office of Management and Budget.

 40 Programmatic Agreement Among U.S.D.A. Forest Service, Pacific Southwest Region (Region 5), California State 

Historic Preservation Officer, Nevada State Historic Preservation Officer, Advisory Council on Historic Preservation 

Regarding the Processes for Compliance with Section 106 of the National Historic Preservation Act for Management of 

Historic Properties by the National Forests of the Pacific Southwest Region, February 2013 (Region 5 PA) 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

361

Analysis Assumptions 

The assumptions used in this effects analysis include: 

• Snowpack creates a protective barrier between vehicles and archaeological sites. Snow levels at

12 inches provide adequate protection.

• All trails are located on engineered roads or trails with gravel, pavement or other base material

or an existing hardened surface. This material acts as a cap for archaeological sites that are 

bisected by the road, thus providing protection to historic properties when snow levels are less 

than 12 inches. [Regional PA stipulation 2.1(c)(1-6)]

• Use of maintained designated roads by OSVs with 6 inches of snow has similar effects to 

vehicles and OHV use on the same road.

Affected Environment 

With over 4,000 recorded sites on National Forest System land, the Tahoe National Forest contains a 

variety of pre-contact and historic archaeological sites and buildings. Research of cultural resources 

discovered within the boundaries of theTahoe National Forest indicate people have been using the 

forest for over 8,000 years with intensification occurring within the last 5,000 to 4,000 years. By 

5,000 years ago on the western side of the forest, permanent villages were established at elevations 

generally below 3,500 feet (snow line). On the eastern side 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 land now managed by the National Forest Service system under the 

administration of the by the Tahoe National Forest. To date, no traditional cultural properties or sites 

of religious or cultural importance have been identified within the Tahoe National Forest. 

Environmental Consequences

Alternative 1 – No Action

Direct and Indirect Effects

Under no action, no new direct effects would occur. Cultural resources would continue to be 

vulnerable to the effects of unregulated over-snow recreation. Sites would continue to be impacted 

when OSVs are used when snow is less than 12 inches. In addition, cultural resources would 

continue to naturally deteriorate over time. Cultural resources would continue to be threatened by 

natural processes (wildfire, erosion, flooding) and from recreational activities that bring people in 

contact with cultural sites.

Alternatives 2, 3, and 5

Direct and Indirect Effects

Direct effects to cultural resources are those that physically alter, damage, or destroy all or part of a 

resource; alter characteristics of the surrounding environment that contribute to the resource’s 

significance; introduce visual or audible elements out of character with the property or that alters its 

setting; or resource neglect to the extent that it deteriorates or is destroyed.
Over-snow Vehicle Use Designation

Tahoe National Forest

362

Under alternatives 2, 3, and 5, direct effects would not likely occur because known sites would be 

covered by 12 inches or more of snow. In addition, all alternatives would not designate cross-country 

OSV use within a 1-acre area near Robinson Flat to protect historic structures. Therefore, these 

alternatives would not directly affect cultural resources within the proposed project area.

Cumulative Effects 

Since alternatives 2, 3, and 5 would not have direct or indirect effects on cultural resources, no 

cumulative effects are anticipated. 

Alternative 4

Direct and Indirect Effects 

This alternative allows for designated cross-country OSV areas only when there are 12 or more 

inches of snow or ice covering the landscape; however, on designated snow trails with underlying 

roads, a minimum of 6 or more inches of snow covering is typically needed to avoid damage to the 

underlying road surface. As long as trails with gravel or paved or hardened surface are used, there 

would be no effect.

This alternative could directly affect cultural resources along two trails that partially do not contain 

an underlying road surface: (1) the Howard Creek OSV Trail overlays Forest Service Road 28. The 

portion of the trail that creates a connection from the Gold Lake Highway (groomed) to Haskell Peak 

OSV Trail does not have a paved road, gravel or road with other base material; and (2) the Andesite 

West OSV Trail partially overlays the Forest Service 14E07. The portion of trail that does not 

overlay this road does not have a paved road, gravel or road with other base material. 

Indirect effects can occur when site visitation increases due to identification of cultural resources 

during recreation activities. Site visitation increases the likelihood for direct effects from looting or 

physically altering the resource.

Cumulative Effects 

The cumulative effects include increased site visitation which results in other sites being identified.

These cumulative effects may result in overall heritage resource landscapes being affected.

Compliance with LRMP and Other Relevant Laws, Regulations, 

Policies and Plans 

Alternative 1 would not be in compliance with Subpart C of the Travel Management Rule, which 

requires designation of roads, trails, and areas on National Forest System lands to provide for OSV

use. Alternative 1 would also not comply with the Region 5 Programmatic Agreement because it 

does not establish a minimum snow depth for trail or cross-country public OSV use.

Alternative 4 would not comply with the Region 5 Programmatic Agreement [Regional PA 

stipulation 2.1(c)(1-6)], which requires all trails be on paved roads, gravel or roads with other base 

material. This material acts as a cap for archaeological sites, thus, providing protection to historic 

properties when snow levels are less than 12 inches. Portions of two trails (Howard Creek and the 

Andesite West OSV Trail) do not have a paved road, gravel or road with other base material

underneath. 

Alternatives 2, 3, and 5 would be in compliance with Subpart C of the Travel Management Rule, the 

Region 5 Programmatic Agreement, and Forest Plan goals to provide a variety of recreation 

opportunities. 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

363

Engineering and Roads

Relevant Laws, Regulations, and Policy

National Forest Roads and Trails Act of October 13, 1964, as amended (16 U.S.C. 532-

538)

This act authorizes road and trail systems for the national forests. It also authorizes granting of 

easements across National Forest System lands, construction and financing of maximum economy 

roads (FSM 7705), and imposition of requirements on road users for maintaining and reconstructing 

roads, including cooperative deposits for that work.

Annual Department of the Interior, Environment, and Related Agencies Appropriations Act

This act appropriates funds for the Forest Service’s road and trail programs.

Organic Administration Act of 1897 (16 U.S.C. 551). 

This act authorizes the regulation of national forests.

National Trails System Act of October 2, 1968 (16 U.S.C. 1241-1249)

This act established the National Trails System and authorizes planning, right-of-way acquisition, 

and construction of trails established by Congress or the Secretary of Agriculture.

Federal Regulations

Code of Federal Regulations

• 36 CFR 212 (Forest Service travel management)

• 36 CFR 251 (Land Uses)

• 36 CFR 261 (Prohibitions)

Forest Service Manual and Handbooks

• FSM 7700 Travel Management

• FSM 7730 Transportation System Operation and Maintenance

• FSH 7709.55 Chapter 10- Travel Planning for Designations

• FSH 7709.59 Chapter 20- Traffic Management

State Direction

• California Snowmobile Trail Grooming (1997 Grooming Standards)

• Over Snow Vehicle Program Final Environmental Impact Report, Program Years 2010 – 2020 

(State of California, Dept. of Parks and Recreation)

• California OSV laws
Over-snow Vehicle Use Designation

Tahoe National Forest

364

Land and Resource Management Plan

Tahoe National Forest Plan

Forestwide transportation system management standards and guidelines (Forest Plan page 40).

Restrict road, trail, and off-highway use to the extent necessary for protection of:

• Threatened, endangered, and sensitive plants or animals

• Essential wildlife functions

• Cultural resources

• Riparian zones and wetlands

Eliminate motorized vehicle use in riparian areas and wetlands except on system roads and

designated routes and stream crossings

Maintain the transportation system to a standard that is commensurate with user types and amount of 

use. Closure of roads and trails will be appropriate if the cost for maintenance and resource 

protection exceeds the benefits received or the financial ability of the forest to pay for these services.

Seasonal road and trail restriction are preferred over permanent closure.

Before deciding to regulate by signing and public announcements as opposed to physical barriers, 

consider the risk to resource values and the magnitude of maintenance costs resulting from 

violations. If physical barriers are used, make sure that private land access needs or cooperative 

agreements requirements are met.

Regulating for single purpose use is not an acceptable objective lf only enacted to meet one group's 

desire. A need to regulate because of user conflict will be evaluated on a case by case bases.

Close roads and trails or regulate traffic when necessary to protect the safety of forest users. 

Candidates for regulation or closure include roads with hazards such as avalanche, landslides, forest 

fires, flooding, timber operations etc.

Conduct a separate analysis to correlate land capability, user needs, and user or landowner conflicts 

forestwide for all dispersed recreation travelways.

Consider the need to protect administrative or special-use facilities when deciding whether to close 

certain roads. Lookouts, guard stations, and transmission sites are examples of such facilities.

Consider the quality of dispersed recreation opportunities when deciding whether to close a road, It 

may be beneficial, for example, to separate four-wheeled motorized recreation use from other forms 

of motorized recreation, especially when simultaneous use diminishes the quality of the recreation 

experience for both users.

Based on the results of a transportation analysis, close and obliterate roads that are not necessary for 

resource management, private land uses, or public uses. Bring the roadbed into resource production. 

Prevent potential resource damage by the obliterated road.

Construct the minimum number of miles of road and meet the minimum design standard possible 

while still meeting safety, user, and resource needs with economic efficiency. Logging system 

design, timber sale design, and transportation planning must be emphasized on all timber sales to 
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

365

comply with this policy. No new roads will be constructed or reconstructed without an approved 

transportation plan and environmental assessment, or environmental impact dtatement, if required.

Proposal for subdivision access over existing National Forest System roads will be addressed.

When planning recreation development projects and resource management activities, coordinate with 

State and local road agencies to address potential traffic impacts and mitigation measures.

Cooperate with the State, other agencies, and user groups to identify, and where compatible with 

Forest Plan management objectives, develop segment of trail that would contribute to a statewide 

trail system. A statewide system would connect use areas and provide the opportunity for longdistance trail touring.

Sierra Nevada Forest Plan Amendment

• No applicable direction

Methodology

The Forest Transportation Atlas was the primary data used, along with professional expertise. The 

atlas is primarily composed of roads and motorized trail information as contained in GIS spatial data 

and Forest Service Infrastructure (INFRA) tabular data. In addition, the proposed over-snow vehicle 

route network for designation, by alternative (GIS data) were included. Last of all, the existing 

National Forest System roads and OSV-related engineering facilities, including snow parks, warming 

huts, parking areas (GIS data) were considered.

All distance figures are approximate values based on the Forest Transportation Atlas (including 

spatial GIS data and tabular INFRA data) and are limited to the accuracy of those sources which 

includes measurements from GIS, GPS, field instruments and aerial photography. Mileages have 

been updated throughout the planning process as better information has been made available and 

may change slightly with additional field verification and project implementation. 

Assumptions

• All OSV users would follow applicable laws and designations as described under each 

alternative.

• All proposed and analyzed OSV trails would be located where the Forest Service has 

jurisdiction. 

Spatial and Temporal Context for Effects Analysis

The affected spatial area where direct, indirect, and cumulative transportation effects may be caused 

by proposed activities involves the project area (Tahoe National Forest).

The temporal boundaries for transportation effects from the proposed activities are indefinite, as long 

as snow conditions exist to provide for the designations as described under each alternative.

Resource Indicators and Measures 

Resource indicators and measures shown in table 19 will be used to measure and disclose effects to 

engineering and roads resources related to OSV use designations and grooming trails for OSV use.
Over-snow Vehicle Use Designation

Tahoe National Forest

366

Table 123. Engineering and roads resource indicators and measures for alternative 1 

Resource 

Element Resource Indicator Measure

Safety Public Safety & Traffic Qualitative effects to motor vehicle operators and 

other users of the trail system

Cost Affordability Qualitative effects to the total cost of maintaining 

the Forest transportation system (FTS) that will 

be open to motor vehicle use

Transportation 

property

Effects to underlying NFS roads 

and trails

Wear and tear that may affect wheeled motor 

vehicle use

Affected Environment

The Tahoe National Forest current management for snow trail grooming when using OHMVR 

Division funds and equipment is to follow OHMVR snow depth standards.

When grooming occurs using other funds and equipment there is currently no minimum snow depth. 

The following summarizes how the Forest Service currently manages OSV use on the approximately

836,273-acre Forest Tahoe National Forest:

• Approximately 638,002 acres of National Forest System land are designated for off-trail crosscountry OSV use;

• Approximately 1,218 acres of National Forest System lands designated for OSV use from 

January 1 through September 14;

• 265 miles of trails for OSV use:

♦ Approximately 217 miles of designated National Forest System OSV trails available for 

grooming;

♦ 41 miles of trails marked, ungroomed for OSV use within OSV Use Areas;

♦ 7 miles of designated OSV trails are not available for grooming;

• OSV use on the PCT is prohibited. There are currently no designated crossings. There is 

currently no OSV prohibition on lands adjacent to the PCT.

• Forest Plan does not establish a minimum snow depth for public OSV cross-country or trail use.

Desired Condition

The desired condition involves providing a stable and cost-efficient road system through appropriate 

construction, reconstruction, maintenance; providing a stable and cost-efficient trail system through 

appropriate construction, reconstruction, maintenance; and providing administrative sites and 

facilities that effectively and cost-efficiently serve the public and the Forest Service workforce.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

367

Environmental Consequences

Alternative 1

Direct and Indirect Effects 

The current Tahoe National Forest Winter Recreation Guide map provides adequate information to 

maintain a reasonable level of public safety and avoid traffic conflicts. There would be minor 

adverse effects (minor costs) due to over-snow vehicle use on access roads to popular parking and 

staging areas. Current snow trail grooming management using OHMVR Division funds and 

equipment follows OHMVR snow depth standards. Snow depth requirement provides adequate 

protection of roads under the snow. Table 124 displays alternative 1 effects on public safety and 

traffic, OSV use effects on the cost of maintaining the transportation system and effects on road and 

trail surfaces.

Table 124. Engineering and roads resource indicators and measures for alternative 1 

Resource 

Element

Resource 

Indicator Measure Alternative 1

Safety Public Safety & 

Traffic

Qualitative effects to 

motor vehicle operators 

and other users of the trail 

system

The current Tahoe National Forest 

Winter Recreation Guide map provides 

adequate information to maintain a 

reasonable level of public safety and 

avoid traffic conflicts 

Cost Affordability Qualitative effects to the 

total cost of maintaining 

the Forest transportation 

system (FTS) that will be 

open to motor vehicle use

Minor effects (minor costs) due to oversnow vehicle use for access roads to 

popular parking and staging areas.

Transportation 

property

Effects to 

underlying NFS 

roads and trails

Wear and tear that may 

affect wheeled motor 

vehicle use

The Tahoe National Forest current 

management for snow trail grooming

using OHMVR Division funds and 

equipment follows OHMVR snow depth 

standards. This snow depth requirement 

provides adequate protection of 

underlying roads.

Alternative 2

Direct and Indirect Effects 

Effects under alternative 2 would be similar to alternative 1. The Tahoe National Forest Winter 

Recreation Guide map would provide adequate information to maintain a reasonable level of public 

safety and avoid traffic conflicts. There would be minor adverse effects (minor costs) due to oversnow vehicle use on access roads to popular parking and staging areas. 

Minimum snow depth requirements would avoid damage to resources, typically a minimum of 

6 inches (OSV use on underlying routes) would provide adequate protection of underlying roads. A 

standard of 12 to 18 inches of snow depth would be required for snow trail grooming when funds 
Over-snow Vehicle Use Designation

Tahoe National Forest

368

and equipment are used from sources other than the OHMVR Division. Snow depth requirement 

would provide adequate protection of roads under the snow.

Minor additional maintenance costs may occur from over-snow vehicle use of access roads, parking 

and staging areas due to:

• Freezing and thawing of road subgrade resulting in asphalt cracking

• Exposure of native surface or asphalt due to grooming, use or rain-on-snow events resulting in 

shortened life-cycle of the infrastructure

• Improvements or maintenance to the storm drainage system may be required due to increased 

runoff and/or earlier snowmelt

Table 125 displays effects on public safety and traffic, OSV use effects on the cost of maintaining the 

transportation system and wear and tear effects on road and trail surfaces.

Table 125. Resource indicators and measures for alternative 2

Resource 

Element

Resource Indicator 

(Quantify if possible)

Measure

(Quantify if possible) Alternative 2

Safety Public Safety & Traffic Qualitative effects to 

motor vehicle operators 

and other users of the trail 

system

The over-snow vehicle use map 

would provide adequate 

information to maintain a 

reasonable level of public safety 

and avoid traffic conflicts; this 

would also improve understanding 

of allowed uses and prohibitions.

Cost Affordability Qualitative effects to the 

total cost of maintaining 

the forest transportation 

system (FTS) that will be 

open to motor vehicle use

Minor effects (additional 

maintenance costs) due to oversnow vehicle use on access roads 

to popular parking and staging 

areas.

Transportation 

property

Effects to underlying 

NFS roads and trails

Wear and tear that may 

affect wheeled motor 

vehicle use

Adequate snow depth requirement,

to avoid damage to resources, 

(OSV use on underlying routes)

typically a minimum of 6 inches 

would provide adequate protection 

of underlying roads. A standard of 

12 to 18 inches of snow depth 

would be required for snow trail 

grooming when funds and 

equipment are used from sources 

other than the OHMVR Division.

Cumulative Effects

There would be negligible cumulative effects under alternative 2. Effects on public safety, road 

maintenance costs and effects on underlying roads and trails would be negligible. Measurement 

indicators are shown in table 126.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

369

Table 126. Engineering and roads resource indicators and measures for alternative 2 cumulative effects

Resource 

Element

Resource Indicator

(Quantify if possible)

Measure

(Quantify if possible) Alternative 2

Safety Public Safety & Traffic Qualitative effects to motor 

vehicle operators and other 

users of the trail system

Negligible cumulative effects; 

temporary closures for logging 

and other forest operations 

activities would eliminate conflicts.

Cost Affordability Qualitative effects to the 

total cost of maintaining the 

forest transportation 

system (FTS) that will be 

open to motor vehicle use

Negligible cumulative effects.

Transportation 

property

Effects to underlying 

NFS roads and trails

Wear and tear that may 

affect wheeled motor 

vehicle use

Negligible cumulative effects; use 

of temporary closures and proper 

use of snow plowing requirements 

for harvest and other forest 

operations activities would 

minimize cumulative effects.

Alternative 3

Direct and Indirect Effects

Effects under alternative 3 would be similar to alternative 1. The over-snow vehicle use map would 

provide adequate information to maintain a reasonable level of public safety and avoid traffic 

conflicts. There would be minor adverse effects (additional costs) due to over-snow vehicle use on 

access roads to popular parking and staging areas.

Adequate snow on roads, 18 inches minimum snow depth for trail grooming and cross-country OSV 

use (OSV use on underlying routes) would provide adequate protection of underlying roads and 

trails.

Minor additional maintenance costs may occur from over-snow vehicle use of access roads, parking 

and staging areas due to:

• Freezing and thawing of road subgrade resulting in asphalt cracking

• Exposure of native surface or asphalt due to grooming, use or rain-on-snow events would

shortened life-cycle of the infrastructure

• Improvements to the storm drainage system may be required due to increased runoff and/or 

earlier snowmelt

Table 127 displays effects on safety, associated transportation costs and effects on road surfaces 

under alternative 3.
Over-snow Vehicle Use Designation

Tahoe National Forest

370

Table 127. Engineering and roads resource indicators and measures for alternative 3

Resource 

Element

Resource Indicator

(Quantify if possible)

Measure

(Quantify if possible) Alternative 3

Safety Public Safety & Traffic Qualitative effects to 

motor vehicle operators 

and other users of the 

trail system

The over-snow vehicle use map 

would provide adequate information 

to maintain a reasonable level of 

public safety and avoid traffic 

conflicts; this would also improve 

understanding of allowed uses and 

prohibitions.

Cost Affordability Qualitative effects to 

the total cost of 

maintaining the forest

transportation system 

(FTS) that will be open 

to motor vehicle use

Minor effects (additional 

maintenance costs) due to oversnow vehicle use for access roads to 

popular parking and staging areas.

Transportation 

property

Effects to underlying 

NFS roads and trails

Wear and tear that may 

affect wheeled motor 

vehicle use

Adequate snow on roads, 18 inches 

for grooming, trail use and crosscountry travel snow depth 

requirements would provide

adequate protection of underlying 

roads.

Cumulative Effects

Cumulative effects of related projects described under alternative 2 would apply to alternative 3.

Table 128 displays cumulative effects under alternative 3.

Table 128. Engineering and roads resource indicators and measures for alternative 3 cumulative effects

Resource 

Element

Resource Indicator

(Quantify if possible)

Measure

(Quantify if possible) Alternative 3

Safety Public Safety & Traffic Qualitative effects to motor 

vehicle operators and 

other users of the trail 

system

Negligible cumulative effects; use 

of temporary closures for logging 

and other forest operations 

activities would eliminate 

conflicts.

Cost Affordability Qualitative effects to the 

total cost of maintaining 

the forest transportation 

system (FTS) that will be 

open to motor vehicle use

Negligible cumulative effects.

Transportation 

property

Effects to underlying 

NFS roads and trails

Wear and tear that may 

affect wheeled motor 

vehicle use

Negligible cumulative effects; use 

of temporary closures and proper 

use of snow plowing 

requirements for harvest and 

other forest operations activities 

would minimize cumulative 

effects.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

371

Alternative 4

Direct and Indirect Effects

The over-snow vehicle use map would provide adequate information to maintain a reasonable level 

of public safety and avoid traffic conflicts. The map and information would also improve 

understanding of allowed OSV uses and prohibitions. Snow depth requirement, 12 inches for 

grooming and 6 inches for OSV use on designated trails would provide adequate protection of 

underlying roads and trails.

Minor additional maintenance costs may occur from over-snow vehicle use of access roads, parking 

and staging areas due to:

• Freezing and thawing of road subgrade resulting in asphalt cracking

• Exposure of native surface or asphalt due to grooming, use or rain-on-snow events would

shortened life-cycle of the infrastructure

• Improvements to the storm drainage system may be required due to increased runoff and/or 

earlier snowmelt

Table 129 displays effects on safety, associated transportation costs and effects on road surfaces 

under alternative 4.

Table 129. Engineering and roads resource indicators and measures for alternative 4

Resource 

Element

Resource Indicator 

(Quantify if possible)

Measure

(Quantify if possible) Alternative 4

Safety Public Safety & Traffic Qualitative effects to 

motor vehicle 

operators and other 

users of the trail 

system

The over-snow vehicle use map would 

provide adequate information to 

maintain a reasonable level of public 

safety and avoid traffic conflicts; this 

would also improve understanding of 

allowed uses and prohibitions.

Cost Affordability Qualitative effects to 

the total cost of 

maintaining the forest

transportation system 

(FTS) that will be open 

to motor vehicle use

Minor effects (additional maintenance 

costs) due to over-snow vehicle use 

for access roads to popular parking 

and staging areas.

Transportation 

property

Effects to underlying 

NFS roads and trails

Wear and tear that 

may affect wheeled 

motor vehicle use

12 inches for grooming and general 

OSV use, and 6 inches for OSV use, 

on underlying routes, snow depth 

requirements would provide adequate 

protection of underlying roads.

Cumulative Effects 

Cumulative effects of related projects described under alternative 2 would apply to alternative 4.

Table 130 displays alternative 4 cumulative effects.
Over-snow Vehicle Use Designation

Tahoe National Forest

372

Table 130. Engineering and roads resource indicators and measures for alternative 4 cumulative effects

Resource 

Element

Resource Indicator

(Quantify if possible)

Measure

(Quantify if possible) Alternative 4

Safety Public Safety & Traffic Qualitative effects to 

motor vehicle operators 

and other users of the 

trail system

Negligible cumulative effects; use of 

temporary closures for logging and 

other forest operations activities 

would eliminate conflicts.

Cost Affordability Qualitative effects to the 

total cost of maintaining 

the forest transportation 

system (FTS) that will be 

open to motor vehicle 

use

Negligible cumulative effects.

Transportation 

property

Effects to underlying 

NFS roads and trails

Wear and tear that may 

affect wheeled motor 

vehicle use

Negligible cumulative effects; use of 

temporary closures and proper use 

of snow plowing requirements for 

harvest and other forest operations 

activities would minimize cumulative 

effects.

Alternative 5

Direct and Indirect Effects

The over-snow vehicle use map would provide adequate information to maintain a reasonable level 

of public safety and avoid traffic conflicts; this would also improve understanding of allowed uses 

and prohibitions. There would be minor costs on access roads to popular parking and staging areas 

due to over-snow vehicle use.

Minimum snow depth requirements would avoid damage to resources, a minimum of 24 inches 

(OSV use on underlying routes) would provide more than adequate protection of underlying roads. A 

minimum of 12 inches of snow depth would be required for snow trail grooming regardless of 

funding. Snow depth requirement would provide adequate protection of roads under the snow.

Minor additional maintenance costs may occur from over-snow vehicle use of access roads, parking 

and staging areas due to:

• Freezing and thawing of road subgrade resulting in asphalt cracking

• Exposure of native surface or asphalt due to grooming, use or rain-on-snow events would

shortened life-cycle of the infrastructure

• Improvements to the storm drainage system may be required due to increased runoff and/or 

earlier snowmelt

Table 131 displays effects on safety, associated transportation costs and effects on road surfaces 

under alternative 5.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

373

Table 131. Engineering and roads resource indicators and measures for alternative 5

Resource 

Element

Resource Indicator 

(Quantify if possible)

Measure

(Quantify if possible) Alternative 5

Safety Public Safety & Traffic Qualitative effects to 

motor vehicle operators 

and other users of the 

trail system

The over-snow vehicle use map 

would provide adequate 

information to maintain a 

reasonable level of public safety 

and avoid traffic conflicts; this 

would also improve understanding 

of allowed uses and prohibitions.

Cost Affordability Qualitative effects to the 

total cost of maintaining 

the forest transportation 

system (FTS) that will be 

open to motor vehicle 

use

Minor effects (additional 

maintenance costs) due to oversnow vehicle use for access roads 

to popular parking and staging 

areas.

Transportation 

property

Effects to underlying 

NFS roads and trails

Wear and tear that may 

affect wheeled motor 

vehicle use

12 inches (grooming, general OSV 

use) and 24 inches of (OSV use on 

underlying routes) snow depth 

requirements would provide

protection of underlying roads.

Cumulative Effects 

Cumulative effects of projects described under alternative 2 would apply to alternative 5. Table 132

displays alternative 5 cumulative effects.

Table 132. Engineering and roads resource indicators and measures for alternative 5 cumulative effects

Resource 

Element

Resource Indicator

(Quantify if possible)

Measure

(Quantify if possible) Alternative 5

Safety Public Safety & Traffic Qualitative effects to motor 

vehicle operators and 

other users of the trail 

system

Negligible cumulative effects; use 

of temporary closures for logging 

and other forest operations 

activities would eliminate conflicts.

Cost Affordability Qualitative effects to the 

total cost of maintaining 

the forest transportation 

system (FTS) that will be 

open to motor vehicle use

Negligible cumulative effects.

Transportation 

property

Effects to underlying 

NFS roads and trails

Wear and tear that may 

affect wheeled motor 

vehicle use

Negligible cumulative effects; use 

of temporary closures and proper 

use of snow plowing requirements 

for harvest and other forest 

operations activities would 

minimize cumulative effects.
Over-snow Vehicle Use Designation

Tahoe National Forest

374

Summary of Environmental Effects

A summary of transportation related environmental effects of alternatives 1 through 5 are shown in table 133.

Table 133. Summary comparison of environmental effects to transportation and engineering resources

Resource 

Element

Indicator/

Measure Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Safety Public Safety 

& Traffic

The current Tahoe

National Forest 

Winter Recreation 

Guide map provides 

adequate 

information to 

maintain a 

reasonable level of 

public safety and 

avoid traffic conflicts 

The over-snow vehicle 

use map would provide 

adequate information 

to maintain a 

reasonable level of 

public safety and avoid 

traffic conflicts; this 

would also improve 

understanding of 

allowed uses and 

prohibitions.

The over-snow vehicle 

use map would provide 

adequate information 

to maintain a 

reasonable level of 

public safety and avoid 

traffic conflicts; this 

would also improve 

understanding of 

allowed uses and 

prohibitions.

The over-snow 

vehicle use map 

would provide 

adequate 

information to 

maintain a 

reasonable level of 

public safety and 

avoid traffic conflicts; 

this would also 

improve 

understanding of 

allowed uses and 

prohibitions.

The over-snow vehicle 

use map would provide 

adequate information to 

maintain a reasonable 

level of public safety and 

avoid traffic conflicts; this 

would also improve 

understanding of allowed 

uses and prohibitions.

Cost Affordability

Minor effects 

(additional 

maintenance costs) 

due to over-snow 

vehicle use on

access roads to 

popular parking and 

staging areas.

Minor effects 

(additional 

maintenance costs) 

due to OSV use on

access roads to 

popular parking and 

staging areas.

Minor effects 

(additional 

maintenance costs) 

due to over-snow 

vehicle use on access 

roads to popular 

parking and staging 

areas.

Minor effects 

(additional 

maintenance costs) 

due to over-snow 

vehicle use on

access roads to 

popular parking and 

staging areas.

Minor effects (additional 

maintenance costs) due 

to over-snow vehicle use 

on access roads to 

popular parking and 

staging areas.
Draft Environmental Impact Statement – Volume I

Chapter 3: Affected Environment and Environmental Consequences

Tahoe National Forest

375

Resource 

Element

Indicator/

Measure Alternative 1 Alternative 2 Alternative 3 Alternative 4 Alternative 5

Transportation 

property

Effects to 

underlying 

NFS roads 

and trails

The Tahoe National 

Forest current 

management for 

snow trail grooming 

using OHMVR 

Division funds and 

equipment follows 

OHMVR snow depth 

standards. This 

snow depth 

requirement 

provides adequate 

protection of 

underlying roads.

Adequate snow depth 

to avoid damage to 

resources requirement, 

typically a minimum of 

6 inches would provide 

adequate protection of 

underlying roads. To 

avoid damaging 

resources for crosscountry travel, a 

minimum of 12 inches 

of un-compacted snow 

is typically needed. 

Twelve to 18 inches

snow depth would be 

required for grooming 

when funds and 

equipment are used 

from sources other 

than the OHMVR 

Division.

Adequate snow on 

roads, 18 inches for 

grooming, trail use and 

cross-country travel

snow depth 

requirements would 

provide adequate 

protection of 

underlying roads.

Twelve inches for 

grooming, general 

OSV use and 

6 inches for OSV 

use on underlying 

routes, snow depth 

requirements would 

provide adequate 

protection of 

underlying roads.

Twelve inches for 

grooming, and 24 inches 

for cross-country travel 

and trail OSV use 

requirement would 

provide protection of 

underlying roads.
Over-snow Vehicle Use Designation

Tahoe National Forest

376

Compliance with LRMP and Other Relevant Laws, Regulations, 

Policies and Plans 

Alternatives 2, 3, 4 and 5 are compliant with all applicable direction, since they all involve 

production of a motor vehicle use map as required in Subpart C of the travel management regulations 

(36 CFR 212).

Alternative 1 does not involve production of a motor vehicle use map as required in Subpart C of the 

travel management regulations. Alternative 1 is otherwise compliant with applicable direction.
Draft Environmental Impact Statement – Volume I

Chapter 4: List of Preparers and Contributors

Tahoe National Forest

377

Chapter 4. List of Preparers and Contributors 

The Forest Service consulted the following individuals, Federal, State, and local agencies, tribes and 

other organization and individuals during the development of this environmental impact statement:

List of Preparers

Name Title/Discipline Relevant Experience Education

Ann Braun Content Analyst, FS

Enterprise Program

3 years content analysis,12 

years information and data 

analysis, and 10 years 

Acquisition Management with 

the U.S. Forest Service

Undergraduate Education

in General Studies, and 

Communication

Tracie Buhl Fire Management 

Specialist, FS 

Enterprise Program 

17 years in Fire 

Management/Natural 

Resources with the U.S. 

Forest Service. Seven years 

conducting air analyses.

Undergraduate education 

in Natural Resources, Fire 

Science.

Tricia Burgoyne Soil Scientist, FS 

Enterprise Program

8 years’ experience working 

as a soil scientist for the U.S. 

Forest Service

BS, Forest Ecology and 

Management

Bruce Davidson Botanist, FS Enterprise 

Program

24 years botany and natural 

resource management with 

the U.S. Forest Service and 

USDI-BLM

BS, Botany

Craig Comstock GIS Support 

Specialist, FS 

Enterprise Program

11 years in GIS management 

with the U.S. Forest Service.

BA, Geography

Pat Goude Writer-Editor, FS 

Enterprise Program

8 years as a writer-editor with 

the U.S. Forest Service

BA, Technical Journalism

Delilah Jaworski Social Scientist, FS 

Enterprise Program

7 years conducting social and 

economic analyses for the 

U.S. Forest Service and other 

Federal land management 

agencies

MSc, Environment and 

Development

Janel McCurdy Interdisciplinary Team 

Leader, FS Enterprise 

Program

17 years leading NEPA 

interdisciplinary teams with the 

U.S. Forest Service

BS, Forest Resource 

Management

Mike McNamara Hydrologist, FS 

Enterprise Program

25 years’ experience as a U.S. 

Forest Service Hydrologist

BS, Geology

MS, Forest Hydrology

Janet Moser Wildlife Biologist, FS 

Enterprise Program

Anthony Olegario Fisheries Biologist, FS 

Enterprise Program

15 years as a U.S. Forest 

Service Fisheries Biologist

BS, Mechanical 

Engineering

MS, Fisheries Science

Kristi Eichner Project Manager, FS 

Enterprise Program

26 years as Project Manager, 

Environmental Specialist, and 

Wildlife Biologist for FS, FWS, 

BOR, and FHWA

BS, Zoology
Over-snow Vehicle Use Designation

Tahoe National Forest

378

Name Title/Discipline Relevant Experience Education

Stephanie 

Valentine

Outdoor Recreation 

Planner, FS Enterprise 

Program

18 years serving as an 

Outdoor Recreation Planner 

for Federal agencies, 6 years 

with the U.S. Forest Service

BS, Outdoor Recreation 

Management

Beth Ann 

Waterston

Content Analyst, 

Project Record, FS 

Enterprise Program

15 years’ experience as a 

forester, with primary 

emphasis in planning and 

silviculture

BS, Natural Resource 

Sciences, Masters course 

work in Ecosystem 

Management

Frank Yurczyk Logging Engineer, FS 

Enterprise Program

50 plus years in transportation 

planning; NEPA (IDT lead); 

fuel reduction and community 

protection operation plans, 

economic efficiency analysis; 

timber sale - planning, design, 

layout, and fire suppression; 

Burn area rehabilitation

BS Forest Management

Interdisciplinary Team Consultants

Name Title Affiliation

Michael Woodbridge Public Affairs Officer/Forest IDTlead Tahoe National Forest

Temoc Rios Public Services Staff Officer Tahoe National Forest

Laura Hierholzer Regional NEPA Coordinator NFS Region 5

Patti Krueger Regional Threatened and Endangered 

Species Coordinator

NFS Region 5

Tina Mark Wildlife, Aquatics, Plants Program Manager Tahoe National Forest

Kathleen E. Mick Program Manager, Trails Motorized 

Recreation Travel Management

NFS Region 5

Rolf Miller GIS Specialist Tahoe National Forest

Laurie Perrot Forest Environmental Coordinator Tahoe National Forest

Carol Purchase Watershed Program Manager Tahoe National Forest

Garrett Villanueva Program Manager, Trails Motorized 

Recreation Travel Management

NFS Region 5

Jeff Wiley OHV Program Manager Tahoe National Forest
Draft Environmental Impact Statement – Volume I

Chapter 4: List of Preparers and Contributors

Tahoe National Forest

379

Distribution of the Environmental Impact Statement to Federal 

agencies, Tribes, elected officials and State and local governments

pursuant to 40 CFR 1502.19.

Federal, State and Local Agencies 

Federal Agencies 

Advisory Council on Historic Preservation, Director, Planning and Review 

U. S. Army Corp of Engineers 

Chief of Naval Operations, Energy and Environmental Readiness Division

Environmental Protection Agency, Region 9, EIS Review Coordinator 

Environmental Protection Agency, Office of Federal Activities, EIS Filing Section

Federal Aviation Administration, Regional Administrator, Western-Pacific Region 

Federal Energy Regulatory Commission

Federal Highway Administration 

National Marine Fisheries Service Habitat Conservationists Division, SW Region

Natural Resources Conservation Service, National Environmental Coordinator

Northwest Power Planning Council

Rural Utilities Service 

Susquehanna River Basins Commission

USDA APHIS PPD/EAD 

USDA National Agricultural Library Head Acquisitions and Serials Branch 

USDA Natural Resources Conservation Service, National Environmental Coordinator 

US Coast Guard, Environmental Management 

US Department of Energy, Director, Office of NEPA Policy and Compliance 

USDI Bureau of Land Management 

USDI Fish and Wildlife Service 

USDI Office of Environmental Policy and Compliance 

California State Agencies 

California Air Resources Board 

California Department of Fish and Game

California Department of Parks and Recreation OHMVR

California Water Resources Control Board 

Local Agencies 

Foresthill Divide Chamber of Commerce

Placer County Air Pollution Control District 

Placer County Public Works 

Pacific Gas & Electric 

Sierra Avalanche Center

Nevada Irrigation District 
Over-snow Vehicle Use Designation

Tahoe National Forest

380

Elected Officials 

Federal Officials 

U.S. Senators

Diane Feinstein 

Kamala Harris

U.S. House of Representatives

Tom McClintock

Doug LaMalfa

California State Officials 

Brian Dahle, California Assembly 

Kristen Olsen, California Assembly 

Tom Berryhill, California Assembly 

Local Officials 

Nevada County Board of Supervisors

Placer County Board of Supervisors 

Sierra County Board of Supervisors 

Tribes 

Colfax-Todd Valley Consolidated Tribe 

Nevada City Rancheria 

Todd Valley Miwok-Maidu Cultural Foundation

United Auburn Indian Community of the Auburn Rancheria 

Washoe Tribe of Nevada and California

Distribution of the Environmental Impact Statement to Individuals

and Organizations

The following individuals and organizations were either contacted directly in the scoping process, or 

made themselves known to the Forest Service by submitting comments during scoping for the Tahoe 

National Forest OSV Designation analysis. These individuals and organizations will be notified of 

the availability of the draft environmental impact statement and the 45-day comment period pursuant 

to 36 CFR 218.24 (a)(3)

Individuals

Last Name or 

Organization

First Name Last Name or 

Organization

First Name

Amador Don Baringer William

Anderson Adam Barker Valerie

Anderson Christine Bazar Kevin

Anderson John Bertram-Gowans Matthew

Augusten Joe Bowering Lynn

Avery Dick Bradford Kevin

Baker Hank Bretthauer Ken

Ball Jeff Brown Chris
Draft Environmental Impact Statement – Volume I

Chapter 4: List of Preparers and Contributors

Tahoe National Forest

381

Last Name or 

Organization

First Name Last Name or 

Organization

First Name

Bane B. Brown Don

Barbarick Ann Bulger Debbie

Burr Eric Farny Cindy

Boyd W. Victor Feenstra Jim

Burr Michelle Feist Travis

Chase Craig Felker Kyle

Chellman Kathryn Felton Kevin

Chickering Nicholas Ferrell Gail

Chisholm Colin Fisher Glenn

Chrisman Bill Flesher Rob

Chrisman Randy Ferris Charles

Clarke Millie Folsom Steve

Combs Ami Gadow Douglas

Condreva Ken Gandolfi Christina

Cordes John George Linda

Corey Jim Gibson Jim

Courts Charles Ginach Danielle

Crismon Mark Gleason Diane

Crosby Casey Gordon Ed

Cross Dan Gordon Pam

Dailey Evan Gordan Ross

Dailey Joanne Grossman Jane

Davey Bryan Grudzien Robert

Davey Mary Halas Sarah

Davis Karen Hallaway Glen

DeCarlo Ed Haug Robert

Deckard Ralph Haupt Craig

Delaney Ryan Hayes Darby

Dieterich Sonja Heifetz Richard

Dines Miriam Heller Morgan

Dines Tom Hendericks Monte

Dooley Mike Hermant Bill

Dunn Travis Hill Rosemary

Durben Rachel Hoffman Janet

Emery Jack Henderson Jerry

Erdoes Jeff Holden Barbara

Erskine Dave Horton Christopher

Ervin Kent Howard Constance

Halverson Joel/Sherry Marancik Dave

Hylton Steve Marsh Glenda

Ingolia Diana Martin Eric
Over-snow Vehicle Use Designation

Tahoe National Forest

382

Last Name or 

Organization

First Name Last Name or 

Organization

First Name

Ivor Pam Martin Jenny

Jacox Susan Martin Rick

Jamsheed Wania Matlin Thelma

John Big McCarthy Forrest

Johnson Curtiss McDermott Helen

Johnson Donna McPherson James

Johnson Whit McMartin Betty

Jones Donna McMartin Janet

Jones Scott McKay Greg

Kedish Eric McNerney Steven

Klemesrud Cliff Price Jack

Kellogg Mike McVay Jared

Kircher Mark Meyer Richard

Klim Ed Meyer R.

Kooyman Justin Miller Bill and Liz

Langbein John Mills Peter

Latta Bob Morgado Craig

Lauer Chuck and Bev Minault Paul

Lazzarino Corky Moore Jim

Leong Robin Morrow Mary

Libkind Marcus Morrow Steve

Lind James Mousset-jones Pierre

Lindsay Keith Muhlbach Scott

Long Kelly Munson James

Lyng Hunter Murphy Michael

MacIntosh Chris Ondracek Ronald

Manke Bill Osburn Kenny

Noack Kenneth Somkin Anthony

Osborn Julie Sommers Keane

Pfister Cliff Sordelli Michael

Poch Lorrie Spielman Michael

Polivy David Suarez Carlos

Pollock Brice Torres JP

Poulsen Glen Triplat Don

Quine Geoff Van Velsor Stan

Rabinowitz Anthony Wadsworth Sarah

Ragan Jane Wania Jamsheed

Riegler Brian Ward Bob

Rogers Leah Ward Shawn

Rosengreen Annemarie Welch Ryan

Rostin Peter White Charles

Rowen Bob Wiley Fred
Draft Environmental Impact Statement – Volume I

Chapter 4: List of Preparers and Contributors

Tahoe National Forest

383

Last Name or 

Organization

First Name Last Name or 

Organization

First Name

Rupp Loren Wilson Chresten

Russell Jake Wood Colin

Russell Sarah Wood Leonard

Schauer Jeffrey Wyeth Harry

Schmitz Scott Zanto Aaron

Scott Melanie Zentner Dave

Smith Steven Zuliani Don

Jennings Jim

Organizations

AAUW Outdoor Enthusiasts 

American Council of Snowmobile Associations 

Birch, Horton, Bittner & Cherot, P.C. 

Blue Ribbon Coalition 

CNSA/Off Road Business Association 

California Wilderness Society 

Clearstream Consulting 

Cragmont Climbing Club 

Disabled Sports USA 

Friends of Independent Lake 

High Camp Hut 

International Snowmobile Manufacturers Association 

Methoe Trails 

Nordic Skiers of Nevada 

North Fork American River Alliance 

North Shore Adventures

Off Road Business Association 

Pacific Crest Trail Association 

Sierra Access Coalition 

Sierra Foothills Audubon Society 

Sierra Club, Bay Chapter 

Sierra Club, Placer Group

Sierra Club Snowcamping 

Sierra Pacific Industries
Over-snow Vehicle Use Designation

Tahoe National Forest

384

Snowlands Network 

Tahoe Sierra Snowmobiling Club 

The Trust for Public Land 

Truckee Donner Land Trust 

Upper American River Foundation

Winter Wildlands Alliance

Wilderness Society
Draft Environmental Impact Statement – Volume I

References

Tahoe National Forest

385

References 

Air Quality

Bishop, G.A., D.A. Burgard, T.R. Dalton, and D.H. 2006. In-use Emission Measurements of 

Snowmobiles and Snowcoaches in Yellowstone National Park. University of Denver, 

Department of Chemistry and BioChemistry. Denver, CO.

BRP. 2011. BRP SKI-DOO Snowmobiles: 10 Models BAT Certified for Yellowstone and Grand 

Teton National Parks. Valcourt, Quebec. www.brp.com

California Air Resource Board (ARB). 2014. Appendix B. California Class I Area Visibility 

Descriptions. www.arb.ca.gov/planning/reghaze/final/appb.pdf. Accessed June 20, 2016.

California Air Resources Board. 2015. California Ambient Air Quality Standards. Online at: 

http://www.arb.ca.gov/desig/desig.htm

California Air Resource Board. 2016. Annual Network Plan. Covering Monitoring Operations in 25 

California Air Districts. June. California Environmental Protection Agency, Air Resources 

Board. https://www.arb.ca.gov/aqd/amnr/amnr2016.pdf

Environmental Protection Agency (EPA). 2010. Exhaust Emission Factors for Non-road Engine 

modeling- Spark-Ignition NR-010f. Assessment of Standards Division, Office of 

Transportation and Air Quality.

EPA. 2015a. AIR Data. Non-attainment listings for criteria pollutants. https://www.epa.gov/greenbook/green-book-pm-25-2012-area-information

EPA. 2015b. Office of Transportation and Emission Standards for nearly all types of non-road 

engines, vehicles and equipment. FAQs. 

Jehl, D. 2002. Air Pollution Regulations Extended to Snowmobiles. The New York Times. 

http://www.nytimes.com/2002/09/14/us/air-pollution-regulations-extended-tosnowmobiles.html

Lopina, C., Air Pollution Specialist, California Air Resources Board. 2015. Personal and email 

communications.

Millner, J. 2015. Snowmobiles in Yellowstone National Park: An American right, or wrong? 

Geoscience Education Web Development Team, Montana State University.

Musselman, R.C. and J.L. Korfmacher. 2007. Air quality at a snowmobile staging area and snow 

chemistry on and off trail in a Rocky Mountain subalpine forest, Snowy Range, Wyoming.

Northern Sierra Air Quality Management District. http://myairdistrict.com/

National Park Service (NPS). 2000. Air quality concerns related to snowmobile usage in National 

Parks. Air Resources Division, Denver, CO. http://www2.nature.

nps.gov/air/Pubs/pdf/yell/Snowmobile_Report.pdf).

Placer County Air Pollution Control District. https://www.placer.ca.gov/departments/air
Over-snow Vehicle Use Designation

Tahoe National Forest

386

U.S. Department of Agriculture Forest Service (USDA Forest Service). 2007. Tahoe National 

Forest’s Land and Resource Management Plan (LRMP). USDA-Forest Service, PSW 

Region, Tahoe National Forest, California 

U.S. Government Publishing Office. 2015. Electronic Code of Federal Regulations. Accessed 

November 2015 at: http://www.ecfr.gov/cgi-bin/textidx?SID=debdc659dece22de01aab5b6a8745c76&mc=true&node=se40.33.1051_1103&rgn=

div8

Valentine, S. 2016a. Five Forest Over-snow Vehicle Tahoe Recreation Report. USDA Forest Service. 

Enterprise Unit.

Valentine, S. 2016b. Email communication- Visitor use data for Tahoe National Forest. June 6, 2016.

Botany

Arnold, J.L., and T.M. Koel. 2006. Effects of Snowmobile Emission on the Chemistry of Snowmelt 

Runoff in Yellowstone National Park. Final Report. Fisheries and Aquatic Sciences Section, 

Center for Resources, Yellowstone National Park, Wyoming. YCR-2006-1.

Bazzaz, F.A. and K. Garbutt. 1998. The Response of Annuals in Competitive Neighborhoods: Effects 

of Elevated CO2. Ecology 69(4): 937-946.

Blanchard, C., H. Michaels, A. Bradman, and J. Harte. 1988. Episodic Acidification of a Lowalkalinity Pond in Colorado. Energy and Resources Group, Berkeley, California. ERG-88-1. 

15 pp.

Davenport J. and T.A. Switalski. 2006. Environmental impacts of transport related to tourism and 

leisure activities. Chapter 14 in J. Davenport and J.A. Davenport (eds.) The ecology of 

transportation: managing mobility for the environment. Springer, Dordrecht. Netherlands.

Davidson, B. 2017. Botany Specialist Report for Tahoe OSV Use Designation project DEIS. 

Unpublished report. USDA Forest Service, Tahoe National Forest, Nevada City, California.

Eagleston, H. and C. Rubin. 2013. Non-motorized winter recreation impacts to snowmelt erosion, 

Tronsen Basin, Eastern Cascades, Washington. Environmental Management 51: 167-181.

Fahey, B. and K. Wardle. 1998. Likely impacts of snow grooming and related activities in the West 

Otago ski fields. Science for Conservation: 85. New Zealand Department of Conservation.

Falkengren-Grerup, U. 1986. Soil acidification and vegetation changes in deciduous forest in 

southern Sweden. Oecologia 70:339-347.

Gage, E. and D.J. Cooper. 2013. Evaluating snow compaction effects to fen wetlands on Rabbit Ears 

and Buffalo Pass of the Routt National Forest. Prepared for the Arapaho-Roosevelt National 

Forests, the White River National Forest, and the Black Hills National Forest.

Greller, A.M., M. Goldstein, and L. Marcus. 1974. Snowmobile impact on three alpine tundra plant 

communities. Environmental Conservation 1(2): 101–110.

Ingersoll, G. 1998. Effects of snowmobile use on snowpack chemistry in Yellowstone National Park, 

USGS, Department of Interior, Water-Resources Investigation Report 99-4148.
Draft Environmental Impact Statement – Volume I

References

Tahoe National Forest

387

Ingersoll, G., J. Turk, C. McClure, S. Lawlor, D. Clow, and A. Mast. 1997. Snowpack chemistry as 

an indicator of pollutant emission levels from motorized winter vehicles in Yellowstone 

National Park, Proceedings of 65th Annual Meeting of Western Snow Conference, May 4-8, 

1997, Banff, Alberta.

Keddy, P.A., A.J. Spavold, and C.J. Keddy. 1979; Snowmobile Impact on Old Field and March 

Vegetation in Nova Scotia Canada: An Experimental Study. Environmental Management

3(5): 409-415.

McNamara, M. 2016. Hydrology Report for Tahoe National Forest Over-Snow Vehicle Use 

Designation DEIS. Unpublished report. USDA Forest Service, Tahoe National Forest, 

Nevada City, California.

Mooney, H.A., M. Kueppers, G. Koch, J. Gorham, C. Chu, and W.E. Winner. 1988. Compensating 

effects to growth of carbon partitioning changes in response to SO2-induced photosynthetic 

reduction in radish. Oecologia, Vol. 75, No. 4, p. 502–506.

Musselman, R.C., and J.L. Korfmacher. 2007. Air quality at a snowmobile staging area and snow 

chemistry on and off trail in a Rocky Mountain subalpine forest, Snowy Range, Wyoming. 

Environmental monitoring and assessment 133(1-3), 321-334.

NatureServe. 2016. NatureServe Explorer: An online encyclopedia of life [web application]. Version 

7.1. NatureServe, Arlington, Virginia. Available online at: http://explorer.natureserve.org 

(Information for Ivesia webberi and Senecio layneae accessed: June 15, 2016).

Neumann, P.W., and H.G. Merriam. 1972. Ecological effects of snowmobiles. Canadian Field 

Naturalist 86:207-212.

Stangl, J.T. 1999. Effects of Winter Recreation on Vegetation. Pages 119-121 in Effects of winter 

recreation on wildlife of the Greater Yellowstone Area: a literature review and assessment. 

Report to the Greater Yellowstone Coordinating Committee. Olliff, T., K. Legg, and B. 

Kaeding, editors. Yellowstone National Park, Wyoming. 315 p.

U.S. Department of Agriculture Forest Service (USDA Forest Service). 2001. Tahoe National Forest 

Land and Resource Management Plan. Tahoe National Forest. Nevada City, California.

USDA Forest Service. 2004. Sierra Nevada Forest Plan Amendment, Final Environmental Impact 

Statement and Record of Decision. Pacific Southwest Region, Vallejo, California.

USDA Forest Service. 2014. Use by Over-snow Vehicles (Travel Management Rule). Federal 

Register, June 18, 2014. 79(117): 34678-34681.

USDA Forest Service. 2016. Tahoe National Forest Threatened, Endangered and Forest Service 

Sensitive Botanical Species. Unpublished document. On file with: Tahoe National Forest, 

Nevada City, California.

U.S. Department of the Interior, Fish and Wildlife Service (USFWS). 1996. Endangered and 

Threatened Wildlife and Plants; Determination of Endangered Status for Four Plants and 

Threatened Status for One Plant From the Central Sierran Foothills of California. Federal 

Register, October 18, 1996. 61(203): 54346-54358.
Over-snow Vehicle Use Designation

Tahoe National Forest

388

USFWS. 2002. Recovery Plan for Gabbro Soil Plants of the Central Sierra Nevada Foothills. 

Portland, Oregon. 220 pp.

Wanek, W.J. 1971. Snowmobile impacts on vegetation, temperatures, and soil microbes. Pp. 116–129 

in Chubb, M (Ed.), Proceedings of the 1971 snowmobile and off-road vehicle research 

symposium, Michigan State University Department of Parks and Recreation Resources 

Technical Report No.8, Michigan State University, East Lansing.

Williams, M.S. 2014. The ecology and distribution patterns of a rare serpentine endemic, Packera 

layneae. Doctoral dissertation, California State University, Chico.

Winner, W.E., and C.J. Atkison. 1986. Absorption of Air Pollution by Plants, and Consequences for

Growth. Trends in Ecology and Evolution. Vol. 1, p. 15–18.

Winter Wildlands Alliance (WWA). 2009. Seeing the Forest and the Trees – Assessing Snowmobile 

Damage in National Forests. A Report by Winter Wildlands Alliance. November, 2009. 3 pp.

Other Botanical Species

Archer, A.J. 2001. Taeniatherum caput-medusae. In: Fire Effects Information System, [Online]. U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences 

Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/ [2016, February 5].

Arnold, J.L., and Koel, T.M. 2007. Effects of Snowmobile Emission on the Chemistry of Snowmelt 

Runoff in Yellowstone National Park. Final Report. Fisheries and Aquatic Sciences Section, 

Center for Resources, Yellowstone National Park, Wyoming. YCR-2006-1.

Bazzaz, F. A. and K. Garbutt. 1998. The Response of Annuals in Competitive Neighborhoods: 

Effects of Elevated CO2. Ecology 69(4): 937-946.

Blanchard, C., H. Michaels, A. Bradman, and J. Harte. 1988. Episodic Acidification of a Lowalkalinity Pond in Colorado. Energy and Resources Group, Berkeley, California. ERG-88-1. 

15 p.

California Invasive Plant Council (CIPC). 2016. Invasive Plant Profiles. Available online at 

http://www.cal-ipc.org/ip/management/plant_profiles/ (accessed 8/9/2016).

Davenport, J. and T.A. Switalski. 2006. Environmental impacts of transport related to tourism and 

leisure activities. Chapter 14 in J. Davenport and J.A. Davenport (eds.) The ecology of 

transportation: managing mobility for the environment. Springer, Dordrecht. Netherlands.

Eagleston, H. and C. Rubin. 2013. Non-motorized winter recreation impacts to snowmelt erosion, 

Tronsen Basin, Eastern Cascades, Washington. Environmental Management 51: 167-181.

Fahey, B. and K. Wardle. 1998. Likely impacts of snow grooming and related activities in the West 

Otago ski fields. Science for Conservation: 85. New Zealand Department of Conservation.

Falkengren-Grerup, U. 1986. Soil acidification and vegetation changes in deciduous forest in 

southern Sweden. Oecologia 70:339-347.

Gage, E. and D.J. Cooper. 2013. Evaluating snow compaction effects to fen wetlands on Rabbit Ears 

and Buffalo Pass of the Routt National Forest. Prepared for the Arapaho-Roosevelt National 

Forests, the White River National Forest, and the Black Hills National Forest.
Draft Environmental Impact Statement – Volume I

References

Tahoe National Forest

389

Greller, A.M., M. Goldstein, and L. Marcus. 1974. Snowmobile impact on three alpine tundra plant

communities. Environmental Conservation 1(2): 101–110.

Ingersoll, G., J. Turk, C. McClure, S. Lawlor, D. Clow, and A. Mast. 1997. Snowpack chemistry as 

an indicator of pollutant emission levels from motorized winter vehicles in Yellowstone

National Park, Proceedings of 65th Annual Meeting of Western Snow Conference, May 4-8, 

1997, Banff, Alberta.

Ingersoll, G. 1998. Effects of snowmobile use on snowpack chemistry in Yellowstone National Park,

USGS, Department of Interior, Water-Resources Investigation Report 99-4148.

Keddy, P.A., A.J. Spavold, and C.J. Keddy. 1979; Snowmobile Impact on Old Field and March 

Vegetation in Nova Scotia Canada: An Experimental Study. Environmental Management

3(5): 409-415.

McNamara, M. 2016. Hydrology Report for Tahoe National Forest Over-Snow Vehicle Use 

Designation DEIS. Unpublished report. USDA Forest Service, Tahoe National Forest, 

Nevada City, California.

Mooney, H.A., M. Kueppers, G. Koch, J. Gorham, C. Chu, and W.E. Winner. 1988. Compensating 

effects to growth of carbon partitioning changes in response to SO2-induced photosynthetic 

reduction in radish. Oecologia, Vol. 75, No. 4, p. 502–506.

Musselman, R.C., and J.L. Korfmacher. 2007. Air quality at a snowmobile staging area and snow 

chemistry on and off trail in a Rocky Mountain subalpine forest, Snowy Range, Wyoming. 

Environmental monitoring and assessment 133(1-3), 321-334.

Neumann, P.W., and H.G. Merriam. 1972. Ecological effects of snowmobiles. Canadian Field 

Naturalist 86:207-212.

Ouren, D.S., C. Haas, C.P. Melcher, S.C. Stewart, P.D. Ponds, N.R. Sexton, L. Burris, T. Fancher, 

and Z.H. Bowen. 2007. Environmental effects of off-highway vehicles on Bureau of Land 

Management lands: A literature synthesis, annotated bibliographies, extensive 

bibliographies, and internet resources. Open-File Report 2007-1353. U.S. Geological Survey. 

Reston, Virginia.

Sikes, K., D. Cooper, S. Weis, T. Keeler-Wolf, M. Barbour, D. Ikeda, D. Stout, and J. Evens. 2013. 

Fen Conservation and Vegetation Assessment in the National Forests of the Sierra Nevada 

and Adjacent Mountains, California. Unpublished report to the U.S. Forest Service, Region 

5.

Stangl, J. T. 1999. Effects of Winter Recreation on Vegetation. Pages 119-121 in Effects of winter 

recreation on wildlife of the Greater Yellowstone Area: a literature review and assessment. 

Report to the Greater Yellowstone Coordinating Committee. Olliff, T., K. Legg, and B. 

Kaeding, editors. Yellowstone National Park, Wyoming. 315 p.

Taylor, K., J. Mangold, and L.J. Rew. 2011. Weed Seed Dispersal by Vehicles. Montana State 

University Extension. MT201105AG. June, 2011.

U.S. Department of Agriculture Forest Service (USDA Forest Service). 1999. Executive Order 

13112. Presidential Documents, Invasive Species, President William Clinton. Federal 

Register Vol. 64, No. 25, February 8, 1999.
Over-snow Vehicle Use Designation

Tahoe National Forest

390

USDA Forest Service. 2005. Forest Service Manual 2670-2671. Threatened, Endangered and 

Sensitive Plants and Animals. Chapter 2670. National Headquarters, Washington, DC. 

Effective: September 23, 2005.

USDA Forest Service. 1990. Tahoe National Forest Land and Resource Management Plan. Tahoe 

National Forest. Nevada City, California.

USDA Forest Service. 2011. Forest Service Manual 2900 – Invasive Species Management. Chapter –

Zero Code. National Headquarters, Washington DC. Effective: December 5, 2011.

USDA Forest Service. 2014. Use by Over-snow Vehicles (Travel Management Rule). Federal 

Register, June 18, 2014. 79(117): 34678-34681.

USDA Forest Service. 2016. Executive Order 13751. Presidential Documents, Invasive Species, 

President Barack Obama. Federal Register Vol. 81, No. 236, December 8, 2016.

Von der Lippe, M. and Kowarik, I. 2007. Long-distance dispersal of plants by vehicles as a driver of 

plant invasions. Conservation Biology. 21(4): 986-996.

Wanek, W.J. 1971. Snowmobile impacts on vegetation, temperatures, and soil microbes. Pp. 116–129 

in Chubb, M. (Ed.), Proceedings of the 1971 snowmobile and off-road vehicle research 

symposium, Michigan State University Department of Parks and Recreation Resources 

Technical Report No.8, Michigan State University, East Lansing.

Winner, W.E., and C.J. Atkison. 1986. Absorption of Air Pollution by Plants, and Consequences for 

Growth. Trends in Ecology and Evolution. Vol. 1, p. 15–18.

Winter Wildlands Alliance (WWA). 2009. Seeing the Forest and the Trees – Assessing Snowmobile 

Damage in National Forests. A Report by Winter Wildlands Alliance. November, 2009. 3 pp.

Aquatic Resources

Adams, E.S. 1975. Effects of lead and hydrocarbons from snowmobile exhaust on brook trout 

(Salvelinus fontinalis). Trans Amer. Fisheries Soc. 104(2): 363-373.

Arnold, J.L., and T.M. Koel. 2007. Effects of Snowmobile Emission on the Chemistry of Snowmelt 

Runoff in Yellowstone National Park. Final Report. Fisheries and Aquatic Sciences Section, 

Center for Resources, Yellowstone National Park, Wyoming. YCR-2006-1.

Avise, J.C., and F.J. Ayala. 1976. Genetic differentiation in species versus depauperate phylads: 

Evidence from the California minnows. Evolution 30: 46-58.

Ayres, W.O. 1854. Remarks on some fish of the cyprinoid family. Daily Placer Times and 

Transcripts, 30 May 1854:1.

Baltz, D.M. and P.B. Moyle. 1993. Invasion resistance by an assemblage of native California stream 

fishes. Ecol. Applic. 3:246-255.

Barreca, A.B. 2010. Overwintering of Cascades Frog (Rana Cascadae) in Washington. A thesis 

presented to the graduate faculty Central Washington University in partial fulfillment of the 

requirements for the degree Master of Science Biology. 
Draft Environmental Impact Statement – Volume I

References

Tahoe National Forest

391

Behnke, R.J. 1979. Monograph of the native trouts of the genus Salmo of western North America. 

U.S. Department of Agriculture, Forest Service, Lakewood, Colorado. 2155 pp.

Behnke, R.J. 1992. Native trout of western North America. American Fisheries Society, Bethesda, 

Maryland. 275 pp.

Bell, R.R. and J.B. Kimsey. 1955. Some considerations of the chemical treatment of the Monticello 

Reservoir basin, Napa County. Calif. Dept. of Fish and Game, Inland Fish. Admin. Rep. No. 

55. 7 pp.

Briggs, C.J., V.T. Vredenburg, R.A. Knapp, and L.J. Rachowicz. 2005. Investigating the populationlevel effects of chytridiomycosis: an emerging infectious disease of amphibians. Ecology

86:3149–3159.

Brown, C. 1997. Personal Communications. Former graduate student at Oregon State University. 

Currently Sierra Nevada Monitoring Strategy Amphibian Monitoring Team Leader with 

USDA Forest Service, PSW Research Station, Berkeley, CA. 

Bulger, J.B., N.J. Scott Jr., and R.B. Seymour. 2003. Terrestrial activity and conservation of adult 

California red-legged frogs Rana aurora draytonii in coastal forests and grasslands. 

Biological Conservation 110: 85-95.

Burch, J.B. 1989. North American Freshwater Snails. Malacological Publications (J. B. Burch, 

Hamburg, Michigan), viii+365 pages.

Buskirk, J. 2002. The western pond turtle, Emys marmorata. Radiata 11(3): 3-30.

Calef, G.W. 1973. Natural mortality of tadpoles in a population of Rana aurora. Ecology 54: 741-

758.

Calhoun, A.J. 1942. The biology of the black-spotted trout (Salmo clarki henshawi) (Gill and Jordan) 

in two Sierra Nevada lakes. Dissertation. Stanford University, Palo Alto, California. 218 pp.

California Off-HighwayMotor Vehicle Recreation (OHMVR) Division. 2010. Over Snow Vehicle 

Program Final Environmental Impact Report, Program Years 2010-2020. State of California, 

Department of Parks and Recreation. Sacramento, California. December, 2010.

Campbell, D., T. Frest, S.A. Clark, E. Johannes and C. Lydeard. 2010 Molecular evidence on the 

phylogeny of the freshwater gastropod Juga (Gastropoda: Cerithiodea:Pleuroceridae) for the 

northwestern United States. Manuscript submitted for publication to The Nautilus.

Cech, J.J., S.J. Mitchell, D.T. Castleberry, and M. McEnroe. 1990. Distribution of California stream 

fishes: influence of environmental temperature and hypoxia. Env. Biol. Fish. 29:95-105.

Coffin, P.D. 1981. Distribution and life history of the Lahontan/Humboldt cutthroat trout, Humboldt 

River drainage basin. Nevada Department of Wildlife, Reno, Nevada. 69 pp.

Coffin, P.D. 1983. Lahontan cutthroat trout fishery management plan for the Humboldt River Basin. 

Federal Aid to Fish Restoration Project Report F-20-17, Study 1X, Job No. 1-P-1. Nevada 

Department of Wildlife, Reno, Nevada. 33 pp.

Coffin, P.D. 1988. Nevada's native salmonid program status, distribution and management. Nevada 

Department of Wildlife, Reno, Nevada. 400 pp.
Over-snow Vehicle Use Designation

Tahoe National Forest

392

Coleman, M.E., and V.K. Johnson. 1988. Summary of trout management at Pyramid Lake, Nevada, 

with emphasis on Lahontan cutthroat trout, 1954-1987. American Fisheries Society 

Symposium 4:107-115.

Cooper, J.J. 1983. Distributional ecology of native and introduced fishes in the Pit River system, 

northeastern California, with note on the Modoc sucker. Calif. Fish and Game 69:39-53.

Cowan, W. 1983. Annual fisheries management report FY-83' Summit Lake Indian Reservation, 

Humboldt Country, Nevada. Unpublished report. Summit Lake Paiute Tribe, Winnemucca, 

Nevada. 37 pp.

Crump, D.E. 2001. Western pond turtle (Clemmys marmorata pallida) nesting behavior and habitat 

use. Master’s Thesis. Paper 2210. http://scholarworks.sjsu.edu/etd_thesis/2210.

Davenport, J. and T.A. Switalski. 2006. Environmental impacts of transport related to tourism and 

leisure activities. Chapter 14 in J. Davenport and J. A. Davenport (eds.). The ecology of 

transportation: managing mobility for the environment. Springer, Dordrecht. Netherlands.

Davidson, B. 2017. Botany Report for Tahoe National Forest Over-Snow Vehicle Use Designation 

Draft Environmental Impact Statement. Unpublished report. USDA Forest Service, Tahoe 

National Forest.

Davidson, C., H.B. Shaffer, and M.R. Jennings. 2001. Declines of the California Red-Legged Frog: 

Climate, UV-B, Habitat, and Pesticides Hypotheses. Ecological Applications 11(2):464-479.

Davidson, C., H. B. Shaffer, and M. R. Jennings. 2002. Spatial Tests of the Pesticide Drift, Habitat 

Destruction, UV-B, and Climate-Change Hypotheses for California Amphibian Declines. 

Conservation Biology 16(6):1588-1601.

Davidson, C. 2004. Declining Downwind: Amphibian Population Declines in California and 

Historical Pesticide Use. Ecological Applications 14(6):1892-1902.

Davis, C.J. 1998. Western pond turtle (Clemmys marmorata). Master’s Thesis. Paper 1694. 

http://scholarworks.sjsu.edu/etd_thesis/1694.

Dever, J.A. 2007. Fine-scale genetic structure in the threatened foothill yellow-legged frog (Rana 

boylii). Journal of Herpetology 41(1): 168-173.

Eagleston, H. and C. Rubin. 2013. Non-motorized winter recreation impacts to snowmelt erosion, 

Tronsen Basin, Eastern Cascades, Washington. Environmental Management 51: 167-181.

Evermann, B.W. 1905. The golden trout of the southern High Sierras. Bull. U.S. Bur. Fish. 25:1-51.

Fahey, B. and K. Wardle. 1998. Likely impacts of snow grooming and related activities in the West 

Otago ski fields. Science for Conservation: 85. New Zealand Department of Conservation.

Fellers, G.M. and C.A. Drost. 1993. Disappearance of the Cascades frog Rana cascadae at the 

southern end of its range, California, USA. Biological Conservation 65: 177-181.

Fellers, G.M. 1995. Aquatic amphibian surveys, Lassen National Forest. Point Reyes, CA: U.S. 

Geological Survey, Biological Resources Division, Point Reyes National Seashore.
Draft Environmental Impact Statement – Volume I

References

Tahoe National Forest

393

Fellers, G.M. 1998. 1996-97 aquatic amphibian surveys, Lassen National Forest. Point Reyes, CA: 

U.S. Geological Survey, Biological Resources Division, Point Reyes National Seashore.

Fellers, G.M. 2005. Rana boylii Baird: Foothill yellow-legged frog. Pp. 534-536. In: Lannoo, M. 

(ed). Amphibian declines: the conservation status of United States species. Univ. Calif. 

Press, Berkeley, CA.

Fellers, G.M., K.L. Pope, J.E. Stead, M. Koo and H. Welsh, Jr. 2008. Turning population trend 

monitoring into active conservation: can we save the Cascades frog (Rana cascadae) in the 

Lassen region of California? Herpetological Conservation and Biology. 3(1): 28-39.

Freel. K. 1997. Herpetologist with USGS, Point Reyes, CA [personal communication with Tahoe 

National Forest Fisheries Biologist].

French, J., and J. Curran. 1991. DRAFT Lahontan cutthroat trout fishery management plan for the 

Quinn River drainage basin. Nevada Department of Wildlife, Reno, Nevada. 46 pp.

Frest, T.J. and E.J. Johannes. 1993. Mollusk Species of Special Concern Within the Range of the 

Northern Spotted Owl. Final Report to the Forest Ecosystem Management Working Group, 

USDA, Forest Service. Deixis Consultants, Seattle WA. 98 pages.

Frest, T.J. and E.J. Johannes. 1995. Freshwater Mollusks of the Upper Sacramento System, 

California, with Particular Reference to the Cantara Spill. 1994 Yearly report to California 

Department of Fish and Game. Deixis Consultants, Seattle, Washington. Contract 

#FG2106R1.

Furnish, J.L. 1990. Factors affecting the growth, production and distribution of the stream snail Juga 

silicula (Gould). Oregon State University (Corvallis), unpublished doctoral dissertation. 

173 pp.

Furnish, J.L. and R. Monthey. 1999. Management recommendations for Survey and Manage aquatic

mollusks, version 2.0, December 1998. USDA Forest Service (Regions 5 and 6) and USDI 

Bureau of Land Management (Oregon, Washington, California), [124 pages], distributed 3 

March 1999. Available online at 

http://www.blm.gov/or/plans/surveyandmanage/MR/AQMollusks/section4.htm

Gerstung, E.R. 1986. Fishery management plant for Lahontan cutthroat trout (Salmo clarki 

henshawi) in California and western Nevada water. Inland Fisheries Administrative Report 

No. 86-, Federal Aid Project F33-R-11, The Resources Agency, California Department of 

Fish and Game. 54 pp.

Gerstung, E.R. 1988. Status, life history, and management of the Lahontan cutthroat trout. American 

Fisheries Society Symposium 4:93-106.

Gage, E. and D.J. Cooper. 2013. Evaluating snow compaction effects to fen wetlands on Rabbit Ears 

and Buffalo Pass of the Routt national Forest. Prepared for the Arapaho-Roosevelt National 

Forests, the White River National Forest, and the Black Hills National Forest.

Germano, D.J. 2010. Ecology of western pond turtles (Actinemys marmorata) at sewage-treatment 

facilities in the San Joaquin Valley, California. The Southwestern Naturalist, 55(1): 89-97. 
Over-snow Vehicle Use Designation

Tahoe National Forest

394

Germano, D.J. and G.B. Rathbun. 2008. Growth, population structure, and reproduction of western 

pond turtles (Actinemys marmorata) on the central coast of California. Chelonian 

Conservation and Biology 7(2): 188-194.

Girard, C. 1854. Description of Sebastues ruber, Sebastes ruber var. parvu, Sebastes variabilis, and 

Centrarchus maculosus. The Pacific 3: 165-209.

Greller, A.M., M. Goldstein, and L. Marcus. 1974. Snowmobile impact on three alpine tundra plant 

communities. Environmental Conservation 1(2): 101–110.

Hayes, M.P. and M.R. Jennings. 1986. Decline of ranid frog species in western North America: are 

bullfrogs (Rana catesbeiana) responsible? Journal of Herpetology 20(4):490-509.

Henderson, J. 1929. The non-marine Mollusca of Oregon and Washington. University of Colorado 

(Boulder) Studies 17(2): 47-190.

Hickman, T., and R.F. Raleigh. 1982. Habitat suitability index models: cutthroat trout. Report 

number USFWS/OBS-82/10.5. USDI, Fish and Wildlife Service, Western Energy and Land 

Use Team, Office of Biological Services, Washington, D.C.

Holznagel, E.E. and C. Lydeard. 2000. A molecular phylogeny of North American Pleuroceridae 

(Gastropoda:Cerithioidea) based on mitochondrial 16S rDNA sequences. Journal of 

Molluscan Studies 66:233-257.

Ingersoll, G., J. Turk, C. McClure, S. Lawlor, D. Clow, and A. Mast. 1997. Snowpack chemistry as 

an indicator of pollutant emission levels from motorized winter vehicles in Yellowstone 

National Park, Proceedings of 65th Annual Meeting of Western Snow Conference, May 4-8, 

1997, Banff, Alberta.

Ingersoll, G. 1998. Effects of snowmobile use on snowpack chemistry in Yellowstone National Park, 

USGS, Department of Interior, Water-Resources Investigation Report 99-4148.

Ingersoll, G.P. 1999. Effects of snowmobile use on snowpack chemistry in Yellowstone National 

Park, 1998. U.S. Geological Survey Water Resources Investigations Report 99-4148. 24 pp.

Interagency Cooperation – Endangered Species Act of 1973, as amended, 50 C.F.R. § 402.02 (2008).

Interagency Cooperation – Endangered Species Act, Title 16 U.S. Code, Pts. 1536. 2004 ed.

Jennings, M.K. 1988. Natural history and decline of native ranids in California. Proceedings of the 

Conference on California Herpetology. Southwestern Herpetologists Society. p. 61-72.

Jennings, M.R. 1997. Research Associate with California Academy of Sciences, San Francisco, CA 

[personal communication with Tahoe National Forest Biologist].

Jennings, M.R. and M.P. Hayes. 1985. Pre-1900 overharvest of California red-legged frogs (Rana 

aurora draytonii): the inducement for bullfrog (Rana catesbeiana) introduction. 

Herpetologica 41 (1): 94-103.

Jennings, M.R. and M.P. Hayes. 1992. Copy of locality records from the data base of Mark R. 

Jennings and Marc P. Hayes for use in support of the petition to list Rana aurora draytonii

under the Endangered Species Act. 30 pp.
Draft Environmental Impact Statement – Volume I

References

Tahoe National Forest

395

Jennings, M.R. and M.P. Hayes. 1994. Amphibian and reptile species of special concern in 

California. California Department of Fish and Game, Final Report. 255 pp.

Johannes, E. 2010. Personal communication, Deixis Consultants, December, 2010.

NatureServe Explorer online: www.natureserve.org/explorer

Johnson, G., D. Bennett, and T. Bjornn. 1983. Juvenile emigration of Lahontan cutthroat trout in the 

Truckee River/Pyramid Lake system. Pages 90-175. In: Restoration of a Reproductive 

Population of Lahontan Cutthroat Trout (Salmo clarki henshawi) to the Truckee 

River/Pyramid Lake System. Special Report U.S. Department of the Interior, Fish and 

Wildlife Service, Great Basin Complex Office, Reno, Nevada.

Jordan, D.S. and B. W. Evermann. 1896. Fishes of North and Middle America. Bull. U.S. Nat. Mus. 

47:1-3705.

Keddy, P.A., A.J. Spavold, and C.J. Keddy. 1979; Snowmobile Impact on Old Field and March 

Vegetation in Nova Scotia Canada: An Experimental Study. Environmental Management

3(5): 409-415.

Knight, N.J. 1985. Microhabitats and temperature requirements of hardhead (Mylopharadon 

conocephalus) and Sacramento squawfish (Ptychocheilus grandis), with notes for some 

other native California stream fishes. Unpubl. Ph.D Dissertation. University of California, 

Davis. 161pp.

Koch, D.L., and J.J. Cooper, E.L. Lider, R L. Jacobson and R.J. Spencer. 1979. Investigations of 

Walker Lake, Nevada: Dynamic ecological relationships. Desert Research Center, University 

of Nevada, Reno. 191 pp.

Kupferberg, S.J. 1996. Hydrologic and geomorphic factors affecting conservation of a river-breeding 

frog (Rana boylii). Ecological Applications 6(4): 1332-1344.

Kupferberg, S.J., A. Catenazzi, K. Lunde, A.J. Lind, and W.J. Palen. 2009. Parasitic copepod 

(Lernaea cyprinacea) outbreaks in foothill yellow-legged frogs (Rana boylii) linked to 

unusually warm summers and amphibian malformations in northern California. Copeia

2009(3): 529-537.

Kupferberg, S.J., A.J. Lind, V. Thill, and S.M. Yarnell. 2011. Water velocity tolerance in tadpoles of 

the foothill yellow-legged frog (Rana boylii): swimming performance, growth, and survival. 

Copeia 2011(1): 141-152.

Lea, T.N. 1968. Ecology of the Lahontan cutthroat trout, Salmo clarki henshawi, in Independence 

Lake, California. Master's thesis. University of California, Berkeley. 95 pp

Leidy, R.A., E. Gonsolin, and G.A. Leidy. 2009. Late-summer aggregation of the foothill yellowlegged frog (Rana boylii) in central California. The Southwestern Naturalist 54(3): 367-368.

Lind, A.J., P.Q. Spinks, G.M. Fellers, and H.B. Shaffer. 2011. Rangewide phylogeography and 

landscape genetics of the Western U.S. endemic frog Rana boylii (Ranidae): implications for 

the conservation of frogs and rivers. Conservation Genetics 12: 269-284.
Over-snow Vehicle Use Designation

Tahoe National Forest

396

Lind, A.J., H.H. Welsh Jr., and R.A. Wilson. 1996. The effects of a dam on breeding habitat and egg 

survival of the foothill yellow-legged frog (Rana boylii) in northwestern California. 

Herpetological Review 27(2): 62-67.

Loomis, R.B. 1965. The yellow-legged frog, Rana boylii, from the Sierra San Pedro Martir, Baja 

California Norte, Mexico. Herpetologica 21(1): 78-80.

Lovich, J. and K. Meyer. 2002. The western pond turtle (Clemmys marmorata) in the Mojave River, 

California, USA: highly adapted survivor or tenuous relict? Journal of Zoology London 256: 

537-545.

Lubcke, G.M. and D.S. Wilson. 2007. Variation in shell morphology of the western pond turtle 

(Actinemys marmorata Baird and Girard) from three aquatic habitats in northern California. 

Journal of Herpetology 41(1): 107-114.

Marrin, D.L. and D.C. Erman. 1982. Evidence against competition between trout and nongame fish 

in Stampede Reservoir, California. No. Amer. J. Fish. Manage. 2:262-269.

McAfee, W.R. 1966. Lahontan cutthroat trout. Pages 225-231 in A. Calhoun, editor. Inland Fisheries 

management. California Department of Fish and Game, Sacramento, California.

McNamara, M. 2017. Hydrology Report for Tahoe National Forest Over-Snow Vehicle Use 

Designation Draft Environmental Impact Statement. Unpublished report. USDA Forest 

Service, Tahoe National Forest, California.

Miller, R.G. 1951. The natural history of Lake Tahoe fishes. Unpubl. Dissertation. Stanford 

University. 160 pp. 

Morey, S. and T. Papenfuss. 1990. Foothill yellow-legged frog Rana boylii. In: California’s Wildlife. 

Vol. I. Amphibians and Reptiles. D. C. Zeiner, W. F. Laudenslayer Jr., K. E. Mayer, and M. 

White. California Department of Fish and Game, Sacramento, California.

Moyle, P.B. 1973. Effects of introduced bullfrogs, Rana catesbeiana, on the native frogs of the San 

Joaquin Valley, California. Copeia: 18-22.

Moyle, P.B. 1976. Inland fishes of California. University of California Press, Berkeley, California. 

405 pages.

Moyle, P.B., J.V.E. Katz, and R.M. Quiñones. 2011. Rapid decline of California’s native inland 

fishes: a status assessment. Biological Conservation 144:2414–2423.

Musselman, R.C., and J.L. Korfmacher. 2007. Air quality at a snowmobile staging area and snow 

chemistry on and off trail in a Rocky Mountain subalpine forest, Snowy Range, Wyoming. 

Environmental monitoring and assessment 133(1-3), 321-334.

Neumann, P.W., and H. G.Merriam. 1972. Ecological effects of snowmobiles. Canadian Field 

Naturalist 86:207-212.

Oullet, M., I. Mikaelian, B.D. Pauli, J. Rodrigue, and D.M. Green. 2005. Historical evidence of 

widespread chytrid infection in North American amphibian populations. Conservation 

Biology 19:1431-1440.
Draft Environmental Impact Statement – Volume I

References

Tahoe National Forest

397

Pacific Gas and Electric (PG&E). 1985. Bald Eagle and Fish Study. Pit 3, 4 and 5 Project. 

Biosystems Analysis, Inc. and University of California, Davis.

Paoletti, D.J., D.H. Olson, and A.R. Blaustein. 2011. Responses of foothill yellow-legged frog (Rana 

boylii) larvae to an introduced predator. Copeia 2011(1): 161-168. 

Polo-Cavia, N., T. Engstrom, P. Lopez, and J. Martin. 2010. Body condition does not predict 

immunocompetence of western pond turtles in altered versus natural habitats. Animal 

Conservation 13: 256-264.

Rankel, G.L. 1976. Fishery management program, Summit Lake Indian Reservation, Humboldt 

County, Nevada. Special Report of the U.S. Fish and Wildlife Service, Division of Fishery 

Services, Reno, Nevada. 35 pp.

Ray, C., M.M. Peacock, and J.B. Dunham. 2007. Demographic and population dynamics of 

Lahontan cutthroat trout (Oncorhynchus clarki henshawi) stream populations in eastern 

Nevada. Final Report to the U.S. Fish and Wildlife Service, Reno, Nevada. Cooperative 

Agreement FSW 14–48–0001–95646. 205 pp.

Reeves, J.G. 1964. Age and growth of the hardhead minnow Mylopharodon conocephalus in the 

American River basin of California, with notes on its ecology. M.S. Thesis. University of 

California, Berkeley. 90 pp.

Richards, R.C., C.R. Goldman, T.C. Frantz, and R. Wickwire. 1975. Where have all the Daphnia

gone? The decline of a major cladoceran in Lake Tahoe, California-Nevada. Verh. Internat. 

Verein. Limnol. 19:835-842.

Rissler, P.H., G.G. Scoppettone, and S. Shea. 2006. Life history, ecology, and population viability 

analysis of the Independence Lake strain Lahontan cutthroat trout (Oncorhynchus clarkii 

henshawi). Final Report. U.S. Geological Survey, Western Fisheries Research Center, Reno, 

Nevada. 68 pp.

Rissler, Pete, USGS. Personal communication. April 2014.

Roberts, B.C., and R.G. White. 1992. Effects of angler wading on survival of trout eggs and preemergent fry. North American Journal of Fisheries Management 12:450-459.

Rombough, C.J. and M.P. Hayes. 2005. Novel aspects of oviposition site preparation by foothill 

yellow-legged frogs (Rana boylii). Northwestern Naturalist 86: 157-160.

Rowley, W. 1955. 1954 creel census, North Fork, Feather River. Calif. Dept. Fish and Game, Inland 

Fish. Admin. Rep. 55 17 pp.

Rutter, C. 1908. The fishes of the Sacramento-San Joaquin basin, with a study of their distribution 

and variation. U.S. Bur. Fish. Bull. 27:143-48.

Sada, D.W., J.E. Williams, J.C. Silvey, A. Halford, J. Ramakka, P. Summers, and L. Lewis. 2001. 

Riparian area management. A guide to managing, restoring, and conserving springs in the 

western United States. Technical Reference 1737-17. Denver, CO. Available online at 

http://digitalcommons.usu.edu/govdocs/252/.
Over-snow Vehicle Use Designation

Tahoe National Forest

398

Sada, D.W. and K.F. Pohlmann. 2002. Spring Inventory and Monitoring ProtocolsConference 

Proceedings. Spring-fed Wetlands: Important Scientific and Cultural Resources of the 

Intermountain Region, 2002. Available online at 

http://www.wetlands.dri.edu/2002/Sada_Pohlmann_Protocol.pdf

Saiki, M.K. 1984. Environmental conditions and fish faunas in low elevation rivers and the irrigated 

San Joaquin Valley floor, California. Calif. Fish and Game 70:145-157

Santos-Barrera, G., G. Hammerson, and G. Fellers. 2004. Rana boylii. In: IUCN 2012. IUCN Red 

List of the Threatened Species. Version 2012.1. <www.iucnredlist.org>. Downloaded on 26 

June 2012.

Schmitz, D., B. McGlynn and D. Patten. 2007. Development of a spring ecosystem monitoring 

protocol in Bighorn Canyon National Recreation Area. Final Report Submitted to the Greater 

Yellowstone Network Inventory and Monitoring Program National Park Service from the 

Land Resources and Environmental Sciences Department, Montana State University, 

Bozeman, MT. Available online at 

http://www.cfc.umt.edu/cesu/NEWCESU/Assets/Individual%20Project%20Reports/NPS%2

0Projects/MSU/2004/McGlynn_seeps_rpt.pdf.

Scoppettone, G.G., P. Rissler, S. Shea, and W. Somer. 2012. Effects of brook trout removal from a 

spawning stream on an adfluvial population of Lahontan cutthroat trout. North American 

Journal of Fisheries Management 32:586–596.

Scott, N.J., G.B. Rathbun, T.G. Murphy, and M.B. Harker. 2008. Reproduction of pacific pond turtles 

(Actinemys marmorata) in coastal streams of central California. Herpetological 

Conservation and Biology 3(2): 143-148.

Sigler, W.F., W.T. Helm, P.A. Kucera, S. Vigg, and G.W. Workman. 1983. Life history of the 

Lahontan cutthroat trout, Salmo clarki henshawi, in Pyramid Lake, Nevada. Great Basin 

Naturalist 43:1-29.

Sigler, W.F., and J.W. Sigler. 1987. Fishes of the Great Basin: A Natural History. University of 

Nevada Press, Reno, Nevada. 425 pp.

Snyder, J.O. 1917. Fishes of the Lahontan system of Nevada and northeastern California. Bull. U.S. 

Bur. Fish. 35:31-86.

Somer, W. 1998. Lahontan Cutthroat Trout, A Threatened Resource. Department of Fish and Game 

Wild Trout Project winter 1998. Vol. 3, No. 2.

Soule, M. 1951. Power development of the Kings River drainage, Fresno County, California. Rep. 

No 3. Junction development of the Kings River and its Middle and South Forks. Calif. Dept. 

Fish and Game, Inland Fish. Admin. Rep. 51. 17 pp.

Sparling, D.W. and G. Fellers. 2007. Comparative toxicity of chlorpyrifos, diazinon, malathion and 

their oxon derivatives to larval Rana boylii. Environmental Pollution 147: 535-539.

Spinks, P.Q. and H.B. Shaffer. 2005. Range-wide molecular analysis of the western pond turtle 

(Emys marmorata): cryptic variation, isolation by distance, and their conservation 

implications. Molecular Ecology 14: 2047-2064.
Draft Environmental Impact Statement – Volume I

References

Tahoe National Forest

399

Storer, T.I. 1925. A synopsis of the Amphibia of California. Univ. Calif. Publ. Zool. 27: 1-342.

Strong, E.E. O. Gargominy, W.F. Ponder and P. Bouchet. 2008. Global diversity of gastropods 

(Gastropoda: Mollusca) in freshwater. Hydrobiologia 595:149-166. Available online at 

http://inpn.mnhn.fr/gargo/strong%20et%20al_2008.pdf .

Sumner, F.H. 1940. The decline of the Pyramid Lake fishery. Transactions of the American Fisheries 

Society 69:216-224.

Taylor, D.W. 1981. Freshwater Mollusks of California: A Distributional Checklist. California 

Department of Fish and Game 67(3):140-163.

U.S. Department of Agriculture Forest Service (USDA Forest Service). 1999. Executive Order 

13112. Presidential Documents, Invasive Species, President William Clinton. Federal 

Register Vol. 64, No. 25, February 8, 1999.

USDA Forest Service. 2001b. Sierra Nevada Forest Plan Amendment, Final Environmental Impact 

Statement.

USDA Forest Service. 2001c. Sierra Nevada Forest Plan Amendment. Final Environmental Impact 

Statement, Record of Decision, Pacific Southwest Region, Jan 2001

USDA Forest Service. 2003. Biological Assessment for SNFPA SEIS. Pacific Southwest Region, 

Vallejo CA. 338pp.

USDA Forest Service. 2005. Forest Service Manual 2670-2671. Threatened, Endangered and 

Sensitive Plants and Animals. Chapter 2670. National Headquarters, Washington, DC. 

Effective: September 23, 2005.

USDA Forest Service. 2011. Forest Service Manual 2900 – Invasive Species Management. Chapter –

Zero Code. National Headquarters, Washington DC. Effective: December 5, 2011.

USDA Forest Service. 2014. Use by Over-Snow Vehicles (Travel Management Rule). Federal 

Register, June 18, 2014. 79(117): 34678-34681.

USDA Forest Service. 2014b. Mountain yellow-legged frog conservation assessment for the Sierra 

Nevada Mountains of California, USA. Pacific Southwest Region, Vallejo, California.

USDI Fish and Wildlife Service (USFWS). 1997. Endangered and Threatened Wildlife and Plants; 

Determination of Endangered Status for Three Plants and Threatened Status for Five Plants 

from Vernal Pools in the Central Valley of California. Federal Register, March 26, 1997. 

62(58): 14338-14352.

USFWS. 2002. Recovery Plan for the California Red-legged Frog (Rana aurora draytonii). US Fish 

and Wildlife Service, Portland, Oregon. Viii + 173pp.

USFWS. 2003. Endangered and threatened wildlife and plants: 12-month finding for a petition to list 

the Sierra Nevada distinct population segment of the mountain yellow-legged frog (Rana 

muscosa). Federal Register, 68:2283-2303. [16 January] 

USFWS. 2003a. Recovery Plan for Fritillaria gentneri (Gentner’s fritillary). U.S. Fish and Wildlife 

Service, Region 1. Portland, Oregon.
Over-snow Vehicle Use Designation

Tahoe National Forest

400

USFWS. 2003b. Endangered and Threatened Wildlife and Plants: Final Designation of Critical 

Habitat for Four Vernal Pool Crustaceans and Eleven Vernal Pool Plants in California and 

Southern Oregon; Final Rule. Federal Register, August 6, 2003. 68(151): 46683-46867.

USFWS. 2005. Recovery plan for vernal pool ecosystems of California and Southern Oregon. 

Portland, OR. 606 pp.

Vander Haegen, W.M., S.L. Clark, K.M. Perillo, D.P. Anderson, and H.L. Allen. 2009. Survival and 

causes of mortality of head-started western pond turtles on Pierce National Wildlife Refuge, 

Washington. The Journal of Wildlife Management 73(8): 1402-1406.

Vindum, J. 1994. Research Associate with California Academy of Sciences, San Francisco, CA 

[personal communication with Tahoe National Forest District Biologist].

Vredenburg, V.T., R. Bingham, R. Knapp, J.A.T. Morgan, C. Moritz, and D. Wake. 2007. Concordant 

molecular and phenotypic data delineate new taxonomy and conservation priorities for the 

endangered mountain yellow-legged frog (Ranidae: Rana muscosa). Journal of Zoology

(London), 271:361-374.

Wake, D.B., and V.T. Vredenburg. 2008. Are we in the midst of the sixth mass extinction? A view 

from the world of amphibians. Proceedings of the National Academy of Sciences 105:11466–

11473.

Wales, J.H. 1946. The hardhead problem in the Sacramento River above Shasta Lake, California. 

Calif. Dept. Fish and Game, Inland fish. Admin. Rep. 46. 4 pp.

Wang, J.C.S. 1986. Fishes of the Sacramento-San Joaquin estuary and adjacent waters, California: A 

guide to the early life histories. Interagency Ecological Study Program for the SacramentoSan Joaquin Estuary, Tech. Rep. 9.

Wheeler, C.A. and H.H. Welsh Jr. 2007. Mating strategy and breeding patterns of the foothill yellowlegged frog (Rana boylii). Herpetological Conservation and Biology 3(2): 128-142.

Winter Wildlands Alliance (WWA). 2009. Seeing the Forest and the Trees – Assessing Snowmobile 

Damage in National Forests. A Report by Winter Wildlands Alliance. November, 2009. 3 pp.

Hydrology

Adams, E.S. 1975. Effects of lead and hydrocarbons from snowmobile exhaust on brook trout 

(Salvelinus fontinalis). Trans Amer. Fisheries Soc. 104(2): 363-373.

Arnold, J.L. and T.M. Koel. 2006. Effects of Snowmobile Emissions on the Chemistry of Snowmelt 

Runoff in Yellowstone National Park. Yellowstone National Park, Center for Resources –

Fisheries and Aquatic Sciences Section. 

http://www.nps.gov/yell/parkmgmt/upload/snwmbil_snwmlt_rpt.pdf

Hagemann, M., and M. Van Mouwerik. 1999. Potential water quality concerns related to 

snowmachine usage. Internal memo. USDI, National Park Service, Water Resources 

Division

Ingersoll, G.P. 1998. Effects of snowmobile use on snowpack chemistry in Yellowstone National 

Park. US Geological Survey Water Resources Investigations Report 99-4148. 24 pp.
Draft Environmental Impact Statement – Volume I

References

Tahoe National Forest

401

Jones, J.A. and G.E. Grant. 1996. Peak flow responses to clear-cutting and roads in small and large 

basins, western Cascades, Oregon. Water Resources Research. 32(4): 959-974.

Kattelmann, R. 1996. Hydrology and water resources. In: Sierra Nevada Ecosystem Project: Final 

report to Congress, Vol. II. Davis: University of California; 855-920.

Keddy, P.A., A.J. Spavold, and C.J. Keddy. 1979. Snowmobile impact on old field and marsh 

vegetation in Nova Scotia, Canada: an experimental study. Environmental Management 3(5): 

409-415.

McDaniel, M.R. 2002. Determination of SVOC in snowmobile exhaust and the driven snow to 

estimate emission and degradation rates of snowmobile-derived contaminants in the winter 

environment. Prepared for ATMS 792, DRI Storm Peak Laboratory, CO. January 2002.

Neumann P.W., and H.G. Merriam. 1972. Ecological effects of snowmobiles. Canadian Field 

Naturalist, volume 86: 207-212.

National Park Service. 2002. Environmental assessment for the management of snowmobiles in 

Rocky Mountain National Park. Prepared by the Dept. of Interior National Park Service, 

Rocky Mountain National Park, Colorado. June 2002.

Olliff, T., K. Legg, and B. Kaeding. 1999. Effects of winter recreation on wildlife of the Greater 

Yellowstone Area: a literature review and assessment. Report to the Greater Yellowstone 

Coordinating Committee. Yellowstone National Park.

Snow Mobile Forum. 2008. Available online at http://www.snowmobileforum.com/general-sledchat/25036-whats-minimum-amount-snow-you-should.html. Accessed 2015. 

U.S. Army Corps of Engineers, 1987. Wetlands delineation manual, Technical report Y-87-1. 

USDA Forest Service. 2001. Sierra Nevada Forest plan amendment: final environmental impact 

statement. Pacific Southwest Region. Vallejo, CA. Available online at 

http://www.fs.fed.us/r5/snfpa/library/archives/feis/index.htm (accessed May 14, 2009).

USDA Forest Service. 2004. Sierra Nevada Forest plan amendment: final supplemental 

environmental impact statement; record of decision. Pacific Southwest Region. Vallejo, CA. 

Available online at: http://www.fs.fed.us/r5/snfpa/final-seis/index.html (accessed May 14, 

2009).

Ziemer, R.R. 1981. Storm flow response to road building and partial cutting in small streams of 

Northern California. Water Resources Research 17(4): 907-917.

Noise

California Department of Parks and Recreation. Off Highway Motor Vehicle Recreation Division. 

Over Snow Vehicle Program. Draft Environmental Impact Report Program Years 2010 –

2020. State Clearinghouse # 2009042113. October 2010.

Harrison, R.T., R.N. Clark, and G.H. Stankey. 1980. Predicting impact of noise on recreationists. 

ED&T Project No. 2688: Noise Pollution Prediction Method. USDA Forest Service, 

Equipment Development Center, San Dimas, CA.
Over-snow Vehicle Use Designation

Tahoe National Forest

402

RAWS USA Climate Archive. 2015. http://www.raws.dri.edu. Station maps data. California, 

Northern. Chester and Blacks Mountain. 

Reed, Sarah E., Ph.D., Jennifer L. Boggs, Jacob P. Mann. 2010. SPreAD-GIS: an ArcGIS toolbox for 

modeling the propagation of engine noise in a wildland setting. Version 2.0. The Wilderness 

Society, San Francisco, CA. October 1, 2010

Reed, Sarah E., Ph.D., Jennifer L. Boggs, Jacob P. Mann. 2012. A GIS tool for modeling 

anthropogenic noise propagation in natural ecosystems. Environmental Modelling & 

Software 37 (2012). P. 1-5 

U.S. Department of Agriculture. Forest Service (USDA Forest Service) 2001. Sierra Nevada Forest 

plan amendment: final environmental impact statement. Pacific Southwest Region. Vallejo, 

CA. http://www.fs.fed.us/r5/snfpa/library/archives/feis/index.htm. 

USDA Forest Service. 2010. Pacific Southwest Region. R5-MB-122b. Final Environmental Impact 

Statement. Motorized Travel Management. Tahoe National Forest.

Recreation

Adams, J.C. and S.F. McCool. 2010. Finite Recreation Opportunities: The Forest Service, the Bureau 

of Land Management, and Off-Road Vehicle Management. Natural Resources Journal. Vol. 

49. 

California Department of Parks and Recreation. Off Highway Motor Vehicle Recreation Division. 

2010. Over Snow Vehicle Program. Draft Environmental Impact Report Program Years 2010 

– 2020. State Clearinghouse # 2009042113. 

Code of Federal Regulations. 36 CFR 212. Travel Management Regulations

Rolloff, D.B., E. Erickson, and B. Niles. 2009. California Department of Parks and Recreation. OffHighway Motor Vehicle Recreation Division. 2009 Winter Trailhead Survey. Dept. of 

Recreation, Parks, and Tourism Administration. College of Health and Human Services. 

California State University, Sacramento.

Snowlands Network. 2014. Analyzing Snowmobile Impacts to Other Winter Recreation Users in the 

Sierra Nevada and Southern Cascades. December 2014.

U.S. Department of Agriculture, Forest Service (USDA Forest Service). 2005. Natural Resource 

Manager. National Visitor Use Monitoring Program. Visitor Use Report. Tahoe National 

Forest. Data Collected in 2005.

USDA Forest Service. 1990. Pacific Southwest Region Tahoe National Forest. Land and Resource 

Management Plan as Amended. 

USDA Forest Service. 2007. Recreation Facility Analysis. 5-year Proposed Program of Work and 

Programmatic Effects of Implementation. Tahoe National Forest. September 2007. 

USDA Forest Service. 2010. Natural Resource Manager. National Visitor Use Monitoring Program. 

Visitor Use Report. Tahoe National Forest. Data Collected in 2010.

USDA Forest Service. 2010. Tahoe National Forest and Lakes Basin Winter Recreation Guide. 

California. 
Draft Environmental Impact Statement – Volume I

References

Tahoe National Forest

403

USDA Forest Service. 2011. IRA 2001 Roadless Acres per Forest (Corrected). Accessed online: 

http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5433333.pdf , 06/09/2016. 

USDA Forest Service. 2012. National Best Management Practices for Water Quality Management on 

National Forest System Lands. FS-990a.

USDA Forest Service. 2015. Natural Resource Manager. National Visitor Use Monitoring Program. 

Visitor Use Report. Tahoe National Forest. Data Collected in 2015.

USDA Forest Service. 2016. Tahoe National Forest Recreation Website. 

http://www.fs.usda.gov/recmain/tahoe/recreation, accessed 6/9/2016. 

Socioeconomic

Allen, S.D., D.A. Wickwar, F.P. Clark, R.R. Dow, R.Potts, and S.A. Snyder. 2009. Values, Beliefs, 

and Attitudes Technical Guide for Forest Service Land and Resource Management, Planning, 

and Decisionmaking. General Technical Report PNW-GTR-788. U.S. Forest Service, Pacific 

Northwest Research Station: Portland, OR. 120 pp.

U.S. Census Bureau. 2016a. American Community Survey, 2010-2014 5-year Estimates. Accessed 

June 16, 2016 at http://factfinder.census.gov.

U.S. Census Bureau. 2016b. County Business Patterns 2013. Accessed June 16, 2016 from EPS 

http://www.headwaterseconomics.org/tools/economic-profile-system.

U.S. Department of Agriculture, Economic Research Service (USDA ERS). 2013. Rural-Urban 

Continuum Codes. Accessed July 23, 2015 at http://www.ers.usda.gov/data-products/ruralurban-continuum-codes/.aspx.

U.S. Department of Agriculture, Forest Service (USDA Forest Service). 2016a. Ecosystem 

Management Coordination, National Forest Recreation Economic Contributions. Accessed 

June 14, 2016 at http://www.fs.fed.us/emc/economics/recreation-contributions.

USDA Forest Service. 2016b. National Visitor Use Monitoring for the Tahoe National Forest, Data 

Collected FY 2010. Accessed June 10, 2016 

http://www.fs.fed.us/recreation/programs/nvum/.

White, E.M. and D.J. Stynes. 2010. Updated Spending Profiles for National Forest Recreation 

Visitors by Activity. Accessed July 23, 2015 Available online at: 

http://www.fsl.orst.edu/lulcd/Publicationsalpha_files/White_Stynes_NVUM2010b.pdf.

White, E.M., D.B. Gooding, and D.J. Stynes. 2013. Estimation of National Forest Visitor Spending 

Averages from National Visitor Use Monitoring: Round 2. General Technical Report PNWGTR-883. U.S. Forest Service, Pacific Northwest Research Station: Portland, OR. 71 pp.

Soils

Baker, E. and E. Buthmann. 2005. Snowmobiling in the Adirondack Park: Environmental and Social 

Impacts. St. Lawrence University, Department of Biology, Canton, New York.

Cacek, C.C. 1989. The relationship of mass wasting to timber harvest activities in the Lightning 

Creek basin. Master Thesis, Eastern Washington University. pp. ii-iv.
Over-snow Vehicle Use Designation

Tahoe National Forest

404

Gage, E. and D.J. Cooper. 2009. Winter recreation impacts to wetlands: a technical review. Report 

for Arapaho-Roosevelt National Forests, White River National Forest and Black Hills 

National Forest. Department of Forest, Rangeland and Watershed Stewardship. Colorado 

State University, Fort Collins, Colorado 80523.

Jurgensen, M.F., A.E. Harvey, R.T. Graham, D.S. Page-Dumrose, J.R. Tonn, M.J. Larson, and T.B. 

Jain. 1997. Impacts of timber harvests on soil organic matter, nitrogen, productivity and 

health of inland northwest forests. Forest Science 43: 234-251.

Keller, T., C. Pielmeier, C. Rixen, F. Gadient, D. Gustafsson, and M. Stahli. 2004. Impact of artificial 

snow and ski-slope grooming on snowpack properties and soil thermal regime in a subalpine ski area. Annals of Glaciology 38: 314-318.

Olliff, T., K. Legg, and B. Kaeding. 1999. Effects of winter recreation on wildlife of the Greater 

Yellowstone Area: a literature review and assessment. Report to the Greater Yellowstone 

Coordinating Committee. Yellowstone National Park.

Page-Dumroese, D.S., M. Jurgensen, and T. Terry. 2010. Maintaining soil productivity during forest 

or biomass-to-energy thinning harvests in the Western United States. Western Journal of 

Applied Forestry 25 (1): 5-11.

State of California, Department of Water Resources. 2007. Climate change in California. 

http://www.water.ca.gov/climatechange/docs/062807factsheet.pdf.

USDA Forest Service and Soil Conservation Service. 1967. Soil Survey: Tehama County California. 

130 pp.

U.S. Department of Agriculture, Forest Service (USDA Forest Service). 1990. Tahoe National Forest 

Land and Resource Management Plan. Nevada City, California.

USDA Forest Service. 1995. Forest Service Handbook, R-5 Supplement 2509.18-95-1. Soil 

Management Handbook. San Francisco, California. 10 pp.

USDA Forest Service. 2012. National Best Management Practices for Water Quality Management on 

National Forest System Lands. Volume 1: National Core BMP Technical Guide. FS-990a. 

177 pp.

Transportation/Engineering

CA. 2010. Over Snow Vehicle Program Final Environmental Impact Report, Program Years 2010 –

2020. California Department of Parks and Recreation, Off-Highway Motor Vehicle 

Recreation Division, Sacramento, CA.

CA. 2012. Off-Highway Vehicle Law Enforcement Information (Quickbook). California Department 

of Parks and Recreation, Off-Highway Motor Vehicle Recreation Division, Sacramento, CA.

U.S. Department of Agriculture, Forest Service (USDA Forest Service). 1990. Tahoe National Forest 

Land and Resource Management Plan. Tahoe National Forest, Nevada City, CA.

USDA Forest Service. 2015. Forest Service Directive System, Forest Service Manuals and 

Handbooks, 7700 Series: Travel Management. USDA Forest Service. Available at

http://www.fs.fed.us/im/directives/, accessed October 31, 2015.
Draft Environmental Impact Statement – Volume I

References

Tahoe National Forest

405

USDA Forest Service. 2016. Forest transportation atlas – GIS Spatial and INFRA Tabular Data, 

Tahoe National Forest. USDA Forest Service, Tahoe National Forest, Nevada City, CA.

U.S. Government. 2015. Code of Federal Regulations. Government Printing Office. Available at

http://www.gpo.gov/fdsys/browse/collectionCfr.action?collectionCode=CFR, accessed 

October 31, 2015.

Terrestrial Wildlife

Allen, A.W. 1987. The relationship between habitat and furbearers. Pages 164-179, In: Novak, M., 

J.A. Baker, and M.E. Obbard, eds. Wildland furbearer management and conservation in 

North America. Ontario Ministry of Natural Resources. 

Anthony, R.G., R.L. Knight, G.T. Allen, B.R. McClelland, and J.I. Hodges. 1982. Habitat use by 

nesting and roosting bald eagles in the Pacific Northwest. U.S. Fish and Wildlife 

Publications, p. 34.

Baker, J.K. 1962. The manner and efficiency of raptor depredations on bats. Condor 64(6):500-504.

Baker, M.D., M.J. Lacki, and G.A. Falxa. 2008. Habitat use of pallid bats in coniferous forests of 

northern California. Northwest Science 82: 269-275.

Barbour, R.W., and W.H. Davis. 1969. Bats of America. University of Kentucky Press, Lexington, 

KY. 286 pp.

Beck, T.W. and J. Winter. 2000. Survey protocol for the great gray owl in the Sierra Nevada of 

California. USDA Forest Service, Pacific Southwest Region, Vallejo, CA. 38 pp.

Bent, A.C. 1961. Life histories of North American birds of prey, Part 1. Dover Publications Inc. New 

York, NY U.S.A.

Blakesley, J.A., M.E. Seamans, M.M. Conner, A.B. Franklin, G.C. White, R.J. Gutiérrez, J.E. Hines, 

J.D. Nichols, T.E. Munton, D.W.H. Shaw, J.J. Keane, G.N. Steger, and T.L. McDonald. 

2010. Population dynamics of spotted owls in the Sierra Nevada, California. Wildlife 

Monographs. 174: 1–36.

Bond, M.L., M.E. Seamans, and R.J. Gutierrez. 2004. Modeling nesting habitat selection of 

California spotted owls (Strix occidentalis occidentalis) in the central Sierra Nevada using 

standard forest inventory metrics. Forest Science 50(6):773-780.

Brown, P.E., R. Berry, and C. Brown. 1994. Foraging behavior of Townsend’s big-eared bats 

(Plecotus townsendii) on Santa Cruz Island. Pages 367-369 in W.L. Halvorson and G.J. 

Maender, editors. Fourth California islands symposium: update on the status of resources. 

Santa Barbara Museum of Natural History, Santa Barbara, CA.

Buehler, D.A., T.J. Mersmann, J.D. Fraser, and J.K. Seegar. 1991. Effects of human activity on bald 

eagle distribution on the northern Chesapeake Bay. The Journal of Wildlife Management

55(2):282-290.

Bull, E.L. and T.W. Heater. 2000. Resting and denning sites of American marten in northeastern 

Oregon. Northwest Science 74(3):179–185.
Over-snow Vehicle Use Designation

Tahoe National Forest

406

Bunnell, K.D., J.T. Flinders, and M.L. Wolfe. 2006. Potential impacts of coyotes and snowmobiles 

on lynx conservation in the intermountain west. Wildlife Society Bulletin, 34(3), pp. 828-838.

Buskirk, S.W. and R.A. Powell. 1994. Habitat ecology of fishers and American martens. In: 

Ruggiero, L.F., Aubry, K.B., Buskirk, S.W. [et al.], tech. eds. 1994. American marten, fisher, 

lynx and wolverine in the western United States: the scientific basis for conserving forest 

carnivores. Gen. Tech. Rep. RM-254. Ft. Collins, CO: U.S. Department of Agriculture, 

Forest Service, Rocky Mountain Forest and Range Research Station. 184 pp.

Cahalane, V.H. 1939. Mammals of the Chiricahua Mountains, Cochise County, Arizona. Journal of 

Mammalogy, 20(4):418-440.

Cain, J.W. and M.L. Morrison. 2003. Reproductive ecology of dusky flycatchers in montane 

meadows of the central Sierra Nevada. Western North American Naturalist 63(4):507-512.

California Department of Fish and Wildlife. California Interagency Wildlife Task Group. 2014. 

CWHR Version 9.0 personal computer program. Sacramento, California.

California Department of Fish and Wildlife (CDFW). 2015a. SNRF species report comments. Email 

w attachment from Chris Stermer, May 29, 2015. 4 pp total In USFWS 2015b.

California Wildlife Habitat Relationships (CWHR). 2013. Species information reports. California 

Wildlife Habitat Relationships Database Version 9.0.

California Department of Parks and Recreation. 2010. Over-snow vehicle program final 

environmental impact report, program years 2010-2020. California Department of Parks and 

Recreation, Off-highway Motor Vehicle Recreation Division. 156 pp.

Call, M. W. 1978. Nesting habits and survey techniques for common western raptors. U. S. Dep. 

Inter., Bur. Land Manage, Portland, OR. Tech. Note No. 316. 115 pp.

Cameron, S.A., J.D. Lozier, J.P. Strange, J.B. Koch, N. Cordes, L.F. Solter, and T.L. Griswold. 2011. 

Patterns of widespread decline in North American bumble bees. Proceedings of the National 

Academy of Sciences 108:662-667. 

Chandler, S.K., J.D. Fraser, D.A. Buehler, and J.K. Seegar. 1995. Perch trees and shoreline 

development as predictors of bald eagle distribution on Chesapeake Bay. The Journal of 

Wildlife Management 59(2):325-332.

Chatfield, A.H. 2005. Habitat selection by a California spotted owl population: a landscape scale 

analysis using resource selection functions. Dept. Fisheries, Wildlife, and Conservation 

Biology, University of Minnesota, St. Paul, Minnesota. 59 pp.

Chung-MacCoubrey, A. L. 1996. Bat species composition and roost use in pinyon-juniper woodlands 

of New Mexico. Pp. 118–123 in Bats and forests symposium (Barclay R. M. R., Brigham R. 

M., eds.). British Columbia Ministry of Forests, Victoria, Canada.

Clark B.S., D.M. Leslie Jr.., and T.S. Carter. 1993. Foraging activity of adult female Ozark big-eared 

bats (Plecotus townsendii ingens) in summer. Journal of Mammalogy 74:422–427.

Clark, D.R., and R.L. Hothem. 1991. Mammal mortality at Arizona, California and Nevada gold 

mines using cyanide extraction. Calif. Fish and Game, 77:61-69.
Draft Environmental Impact Statement – Volume I

References

Tahoe National Forest

407

Cockrum, E.L. and B.F. Musgrove. 1964. Additional records of the Mexican big-eared bat, Plecotus 

phyllotis (Allen), from Arizona. Journal of Mammalogy 45(3):472-474.

Cockrum, E.L. and E. Ordway. 1959. Bats of the Chiricahua Mountains, Cochise County, Arizona. 

American Museum novitates; no. 1938.

Commissaris, L.R. 1961. The Mexican big-eared bat in Arizona. J. Mammal. 42, 61–65.

Conner, M.M., J.J. Keane, C.V. Gallagher, G. Jehle, T.E. Munton, P.A. Shaklee, and R.A. Gerrard.

2013. Realized population change for long-term monitoring: California spotted owl case 

study. The Journal of Wildlife Management, 77(7):1449-1458.

Copeland, J.P., K.S. McKelvey, K.B. Aubry, A. Landa, J. Persson, R.M. Inman, J. Krebs, E. Lofroth, 

H. Golden, J.R. Squires, and A. Magoun. 2010. The bioclimatic envelope of the wolverine 

(Gulo gulo): do climatic constraints limit its geographic distribution? Canadian Journal of 

Zoology, 88(3):233-246.

Copeland, J.P., J.M. Peek, C.R. Groves, W.E. Melquist, K.S. McKelvey, G.W. McDaniel, C.D. Long, 

and C.E. Harris. 2007. Seasonal habitat associations of the wolverine in central Idaho.

Journal of Wildlife Management 71:2201-2212.

Cryan, P. 1997. Distribution and roosting habits of bats in the southern Black Hills, South Dakota. 

Unpublished Master’s Thesis, University of New Mexico, Albuquerque, NM. 96 pp.

Dalquest, W.W. 1947. Notes on the natural history of the bat Corynorhinus rafinesquii in California.

Journal of Mammalogy 28(1):17-30.

Detrich, P.J. and B. Woodbridge. 1994. Territory fidelity, mate fidelity, and movements of colormarked northern goshawks in the southern Cascades of California. Studies in Avian Biology

16:130-132.

Dobkin D.S., R.G. Gettinger, and M.G. Gerdes. 1995. Springtime movements, roost use, and 

foraging activity of Townsend's big-eared bat (Plecotus townsendii) in central Oregon. Great 

Basin Naturalist 55:315–321.

Dunk, J.R, J.J. Keane, A.E. Bowles, T. Narahashi, D.L. Hansen, S. Vigallon, and J.J.V.G Hawley. 

2011. Experimental effects of recreation on northern goshawks – final report submitted to 

the USDA Forest Service Region 5 Office. 71 pages.

Easterla, D.A. 1966. Yuma myotis and fringed myotis in southern Utah. Journal of Mammalogy, 

47(2):350-351.

Esmoil, B.J., and S.H. Anderson. 1995. Wildlife mortality associated with oil pits in Wyoming. 

Prairie Naturalist, 27:81-88.

Evans, E., R. Thorp, S. Jepsen, and S.H. Black. 2008. Status Review of Three Formerly Common 

Species of Bumble Bee in the Subgenus Bombus: Bombus affinis (the rusty patched bumble 

bee), B. terricola (the yellowbanded bumble bee), and B. occidentalis (the western bumble 

bee). The Xerces society, Portland, OR. 

Fellers, G.M., and E.D. Pierson. 2002. Habitat use and foraging behavior of Townsend's big-eared 

bat (Corynorhinus townsendii) in coastal California. Journal of Mammalogy 83:167-177.
Over-snow Vehicle Use Designation

Tahoe National Forest

408

Findley, J.S., and N.C. Negus. 1953. Notes on the mammals of the gothic region, Gunnison County, 

Colorado. Journal of Mammalogy, 34(2):235-239.

Flickinger, E.L., and C.M. Bunck. 1987. Number of oil-killed birds and fate of bird carcasses at 

crude oil pits in Texas. Southwestern Nat., 32:377-381.

Forsman, E.D., E.C. Meslow, and H.M. Wight. 1984. Distribution and biology of the spotted owl in 

Oregon. Wildlife Monographs. 87:1–64.

Fraser, J.D., L.D. Frenzel, and J.E. Mathisen. 1985. The impact of human activities on breeding bald 

eagles in north-central Minnesota. The Journal of Wildlife Management 49(3):585-592.

Frost, D.R., and R.M. Timm. 1992. Phylogeny of plecotine bats (Chiroptera: "Vespertilionidae"): 

proposal of a logically consistent taxonomy. Am. Mus. Novitates 3034:1-16.

Gaines, W.L., P.H. Singleton, and R.C. Ross. 2003. Assessing the Cumulative Effects of Linear 

Recreation Routes on Wildlife Habitats on the Okanogan and Wenatchee National Forests. 

Gen. Tech. Rep. PNW-GTR-586. Portland, OR: U.S. Department of Agriculture, Forest 

Service, Pacific Northwest Research Station. 79 pp. 

http://www.fs.fed.us/pnw/pubs/gtr586.pdf.

Graham, R.T., R.T. Reynolds, M.H. Reiser, R.L. Bassett, D.A. Boyce. 1994. Sustaining forest habitat 

for the Northern goshawk: A Question of Scale. Studies of Avian Biology. No.16 

Green, G.A., H.L. Bombay, and M.L. Morrison. 2003. Conservation assessment of the willow 

flycatcher in the Sierra Nevada. Foster Wheeler Environmental Corporation and the 

University of California. 67 pp.

Grubb, T.G. and R.M. King. 1991. Assessing human disturbance of breeding bald eagles with 

classification tree models. The Journal of Wildlife Management 55(3):500-511.

Grubb, T.G., A.E. Gatto, L.L. Pater, and D.K. Delaney. 2012. Response of nesting northern goshawks 

to logging truck noise, Kaibab National Forest, Final Report. USDA Forest Service, 

Southwest Region. 31 pp.

Gutierrez R.J. and G.F. Barrowclough. 2005. Redefining the distributional boundaries of the northern 

and California spotted owls: implications for conservation. Condor 107:182-187.

Gutierrez, R.J., A.B. Franklin, and P.C. Carlson. 1995a. Population ecology of the northern spotted 

owl (Strix occidentalis caurina) in northwestern California: annual results, 1994. Annual 

Progress Report (Contract #53-91S8-4-FW20) to Region 5, USDA Forest Service. 

Contractor: Humbolt State University, Arcata, CA.

Gutierrez R.J., A.B. Franklin, and W.S. LaHaye. 1995b. Spotted owl (Strix occidentalis). The birds 

of North America, number 179. The American Ornithologists’ Union, Washington D.C. 

USA, and the Academy of Natural Sciences, Philadelphia, Pennsylvania.

Gutierrez, R.J., M.Z. Peery, D.J. Tempel, and W.J. Berigan. 2012. Population ecology of the 

California spotted owl in the central Sierra Nevada: annual results 2011. USDA Forest 

Service, Region 5. 39 pp.

Hatfield, R. 2012. Records of western and Franklin’s bumble bees in the western United States. 

Database records provided by the Xerces Society, Portland, OR on 2/29/12.
Draft Environmental Impact Statement – Volume I

References

Tahoe National Forest

409

Hayward, L.S., A.E. Bowles, J.C. Ha, and S.K. Wasser. 2011. Impacts of acute and long-term vehicle 

exposure on physiology and reproductive success of the northern spotted owl. Ecosphere. 

2(6): article 65.

Hermanson, J.W., and T.J. O’Shea. 1983. Antrozous pallidus. American Society of Mammalogists, 

Mammalian Species 213:1-8.

Hirshfeld, J.R. and M.J. O'Farrell. 1976. Comparisons of differential warming rates and tissue 

temperatures in some species of desert bats. Comparative Biochemistry and Physiology Part 

A: Physiology, 55(1):83-87.

Hopwood, J., M. Vaughan, M. Shepherd, D. Biddinger, E. Mader, S. Hoffman Black and C. 

Mazzacano. 2012. Are Neonicotinoids Killing Bees? A Review of Research into the Effects 

of Neonicotinoid Insecticides on Bees, with Recommendations for Action. Xerces Society, 

Portland, OR. Available at http://www.xerces.org/wp-content/uploads/2012/03/AreNeonicotinoids-Killing-Bees_Xerces-Society1.pdf

Hornocker, M.G. and H.S. Hash. 1981. Ecology of the wolverine in northwestern Montana. 

Canadian Journal of Zoology, 59(7):1286-1301.

Humphrey, S.R., and T.H. Kunz. 1976. Ecology of a Pleistocene relict, the western big-eared bat 

(Plecotus townsendii), in the southern great plains. Journal of Mammalogy 57(3):470-494.

Johnston, D.S. and J.R. Gworek. 2006. Pallid bat (Antrozous pallidus) habitat use in a coniferous 

forest in northeastern California. Bat Research News 47:114.

Johnston, D.S., B. Hepburn, J. Krauel, T. Stewart, and D. Rambaldini. 2006. Winter ecology of pallid 

bats in central coastal California. Bat Research News 47:115.

Johnston, D.J., G. Tatarian, and E.D. Pierson. 2004. California bat mitigation: techniques, solutions, 

and effectiveness. Contract Report #2394-01 for California Department of Transportation, 

Sacramento, CA, 125 pp.

Jones, C., and R.D. Suttkus. 1972. Notes on netting bats for eleven years in western New Mexico.

Southwestern Naturalist 16(3/4):261-266.

Kalinowski, R.S., M.D. Johnson, and A. Rich. 2014. Habitat relationships of great gray owl prey in 

meadows of the Sierra Nevada mountains. Wildlife Society Bulletin 38(3):547-556.

Kirk, T.A. and W.J. Zielinski. 2009. Developing and testing a landscape habitat suitability model for 

the American marten (Martes americana) in the Cascades mountains of California. 

Landscape Ecology 24:759–773.

Knight, R.L., and S.K. Knight. 1984. Responses of wintering bald eagles to boating activity. Journal 

of Wildlife Management 48:999-1004.

Knight, R.L. and S.K. Skagen. 1988. Agonistic Asymmetries and the Foraging Ecology of Bald 

Eagles. Ecology 69(4):1188-1194.

Koch, J., J. Strange, and P. Williams. 2012. Bumble Bees of the Western United States. U.S. Forest 

Service and the Pollinator Partnership, Washington, D.C. 144 pp.
Over-snow Vehicle Use Designation

Tahoe National Forest

410

Kunz, T.H., and R.A. Martin. 1982. Plecotus townsendii. American Society of Mammalogists, 

Mammalian Species 175:1-6.

Lewis, S.E. 1994. Night roosting ecology of pallid bats (Antrozous pallidus) in Oregon. American 

Midland Naturalist 132(2):219-226.

Lewis, S.E. 1996. Low roost-site fidelity in pallid bats: associated factors and effect on group 

stability. Behavioral Ecology and Sociobiology 39(5):335-344.

Magoun, A.J. and J.P. Copeland. 1998. Characteristics of wolverine reproductive den sites. The 

Journal of Wildlife Management, pp. 1313-1320.

Marcot B. G. 1984. Winter use of some northwestern California caves by western big-eared bats and 

long-eared Myotis. Murrelet 65:46.

Mathewson, H.A., M.L. Morrison, H.L. Loffland, and P.F. Brussard. 2013. Ecology of Willow 

Flycatchers (Empidonax traillii) in the Sierra Nevada, California: Effects of Meadow 

Characteristics and Weather on Demographics. Ornithological Monographs 75.

Mazurek, M.J. 2004. A maternity roost of Townsend's big-eared bats (Corynorhinus townsendii) in 

coast redwood basal hollows in northwest California. Northwestern Naturalist 85: 60-62.

McNamara, M. 2015. Over-snow Vehicle Use Designation Environmental Impact Statement 

Hydrology Report.

Miller, G.S. 1989. Dispersal of juvenile northern spotted owls in western Oregon. M.S. Thesis, 

Oregon State Univ. Corvallis. 139 pp.

Moriarty, K. 2011. Decline in American marten occupancy rates at Sagehen Experimental Forest, 

California. The Journal of Wildlife Management 75(*):1774-1787.

Moriarty, K., W.J. Zielinski, A.G. Gonzales, T.E. Dawson, K.M. Boatner, C.A. Wilson, F.V. Schlexer, 

K.L. Pilgrim, J.P. Copeland, and M.K. Schwartz. 2009. Wolverine confirmation in California 

after nearly a century: native or long-distance immigrant? Northwest Science 83(2):154-162.

Morrison, M.L., R.J. Young, J.S. Rosmos, and R. Golightly. 2011. Restoring forest raptors: Influence 

of human disturbance and forest condition on northern goshawks. Restoration Ecology

19(2):273-279.

Murphy, D.D., and C.M. Knopp. 2000. Lake Tahoe watershed assessment. General Technical ReportPacific Southwest Research Station, USDA Forest Service.

O’Farrell. M.J., and W.G. Bradley. 1970. Activity patterns of bats over a desert spring. Journal of 

Mammalogy 51(1):18-26.

O’Farrell, M.J., W.G. Bradley, and G.W. Jones. 1967. Fall and winter bat activity at a desert spring in 

southern Nevada. Southwestern Naturalist 12:163-171.

O’Farrell, M.J. and E.H. Studier. 1980. Myotis thysanodes. Mammalian Species 137:1-5.

Olson, L.E., J.D. Sauder, N.M. Albrecht, R.S. Vinkey, S.A. Cushman, and M.K. Schwartz. 2014. 

Modeling the effects of dispersal and patch size on predicted fisher (Pekania [Martes] 

pennanti) distribution in the U.S. Rocky Mountains. Biological Conservation 169:89-98.
Draft Environmental Impact Statement – Volume I

References

Tahoe National Forest

411

Pearson, O.P., M.R. Koford, and A.K. Pearson. 1952. Reproduction of the lump-nosed bat 

(Corynorhinus rafinesquei) in California. Journal of Mammalogy 33(3):273-320.

Purcell, K.L., C.M. Thompson, and W.J. Zielinski. 2012. Fishers and American martens. Pp. 47-60 In 

Managing Sierra Nevada forests (M. North, editor). USDA Forest Service, Pacific Southwest 

Research Station Albany, CA. General Technical Report PSW-GTR-237. 

Rabe, M.J., T.E. Morrell, H. Green, J.C. deVos, Jr., and C.R. Miller. 1998. Characteristics of 

ponderosa pine snag roosts used by reproductive bats in northern Arizona. Journal of 

Wildlife Management 62(2):612-621.

Roberts, S. and M. North. 2012. California Spotted Owls. Chapter 5 in PSW-GTR-237 Managing 

Sierra Nevada Forests, USDA Forest Service, Pacific Southwest Research Station.

Roest, A.I. 1951. Mammals of the Oregon Caves area, Josephine County. Journal of Mammalogy

32:345-351.

Ruggiero, L.F., D.E. Pearson, S.E. Henry. 1998. Characteristics of American marten den sites in 

Wyoming. Journal of Wildlife Management 62(2):663–673.

Rustigian-Romsos, H.L. and W.D. Spencer. 2010. Predicting habitat suitability for the American 

marten on the Lassen National Forest, final report. Produced by Conservation Biology 

Institute. 33pp.

Sample B.E. and R.C. Whitmore. 1993. Food habits of the endangered Virginia big-eared bat in West 

Virginia. Journal of Mammalogy 74:428–435

Sherwin, R.E., D. Stricklan, and D.S. Rogers. 2000. Roosting affinities of Townsend's big-eared bat 

(Corynorhinus townsendii) in northern Utah. Journal of Mammalogy 81:939-947.

Siegel, R.B. R.L. Wilkerson, and D. DeSante. 2008. Extirpation of the willow flycatcher from 

Yosemite National Park. Western Birds 39:8-21.

Spencer, W. and H. Rustigian-Romsos. 2012. Decision support maps and recommendations for 

conserving rare carnivores in the interior mountains of California. Conservation Biology

Institute. 36 pp. + Appendices.

Spencer, W.D., R.H. Barrett, and W.J. Zielinski. 1983. Marten habitat preferences in the northern 

Sierra Nevada. Journal of Wildlife Management 47(4):1181-1186.

Squires, J.R. and R.T. Reynolds. 1997. Northern Goshawk (Accipiter gentilis), The Birds of North 

America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the 

Birds of North America Online: http://bna.birds.cornell.edu/bna/species/298.

Stalmaster, M.V. and J.L. Kaiser. 1998. Effects of recreational activity on wintering bald eagles. 

Wildlife Monographs 137:1-46.

Stalmaster, M.V., and J.R. Newman. 1978. Behavioral responses of wintering bald eagles to human 

activity. Journal of Wildlife Management 42:506-13.

Stefani, R.A., H.L. Bombay, and T.M. Benson. 2001. Willow Flycatcher. Pages 143- 195 in USDA 

Forest Service, Sierra Nevada Forest Plan Amendment Final Environmental Impact 
Over-snow Vehicle Use Designation

Tahoe National Forest

412

Statement, vol. 3, Ch. 3, Part 4.4. USDA Forest Service, Pacific Southwest and 

Intermountain Regions, Sacramento, CA.

Tempel, D.J. and R.J. Gutierrez. 2003. Fecal corticosterone levels in California spotted owls exposed 

to low-intensity chainsaw sound. Wildlife Society Bulletin 31(3):698-702.

Tempel, D.J. and R.J. Gutiérrez. 2004. Factors related to fecal corticosterone levels in California 

spotted owls: implications for assessing chronic stress. Conservation Biology 18(2):538-547.

Thorp, R.W., and M.D. Shepherd. 2005. Profile: Subgenus Bombus. In Shepherd, M.D., D.M. 

Vaughan, and S.H. Black (eds). Red List of Pollinator Insects of North America. The Xerces 

Society for Invertebrate Conservation, Portland, OR.

Thorp, R. 2015. Personal communication between R. Thorp (Distinguished Professor Emeritus, 

Department of Entomology and Nematology, University of California Davis) and Katherine 

Malengo regarding hibernation habitat for western bumble bee (Bombus occidentalis).

October 19, 2015.

Tommasi, D., A. Miro, H.A. Higo, and M.L. Winston. 2004. Bee diversity and abundance in an 

urban setting. The Canadian Entomologist 136:851–869.

U.S. Department of Agriculture, Forest Service (USDA Forest Service). 2001. Sierra Nevada Forest 

plan amendment: final environmental impact statement. Department of Agriculture, Forest 

Service, Pacific Southwest Region [USDA FS PSW Region]. 2001. Vallejo, CA. 

http://www.fs.usda.gov/detail/r5/landmanagement/planning/?cid=stelprdb5415847 .

USDA Forest Service. 2004. Record of Decision for Sierra Nevada Forest Plan Amendment.

USDA Forest Service. 2007. Land and Resource Management Plan Tahoe National Forest 

(Amended). Pacific Southwest Region. 

U.S. Department of the Interior, Fish and Wildlife Service (USFWS). 1986. Pacific Bald Eagle 

Recovery Plan. U.S. Fish and Wildlife Service, Portland, Oregon.

USFWS. 1998. Endangered Species Consultation Handbook: Procedures for Conducting 

Consultation and Conference Activities Under Section 7 of the Endangered Species Act.

USFWS. 2006. 50 CFR Part 17. Endangered and Threatened Wildlife and Plants; 12-month finding 

for a petition to list the California spotted owl (Stirx occidentalis occidentalis) as threatened 

or endangered. Federal Register. Vol 71, No 100, May 24, 2006.

USFWS. 2007. Bald eagle management guidelines and conservation measures.

USFWS 2012. Federal Register, Department of the Interior, 50 CFR Part 17. Endangered and 

Threatened Wildlife and Plants; Designation of Revised Critical Habitat for the Northern 

Spotted Owl; Final Rule. Vol 77, No 233.

USFWS. 2013. Endangered and Threatened Wildlife and Plants; Threatened Status for the Distinct 

Population Segment of the North American Wolverine Occurring in the Contiguous United 

States. Federal Register 78(23):7864-7890.
Draft Environmental Impact Statement – Volume I

References

Tahoe National Forest

413

USFWS. 2016. Tahoe National Forest over-snow vehicle use designation updated list of threatened 

and endangered species that may occur in your proposed project location, and/or may be 

affected by your proposed project. Sacramento Fish and Wildlife Office. 

USDI National Park Service. 2013. Yellowstone National Park Winter Use Plan /Supplemental 

Environmental Impact Statement Wyoming, Montana, Idaho. Chapter 3, Pages 90-91.

Van Riper, C. III, J.J. Fontaine, and J.W. van Wagtendonk. 2013. Great gray owls (Strix nebulosa) in 

Yosemite National Park: on the importance of food, forest structure, and human disturbance. 

Natural Areas Journal 33(3):286-295.

Vaughan, T.A., and T.J. O’Shea. 1976. Roosting ecology of the pallid bat, Antrozous pallidus.

Journal of Mammalogy 57(1):19-42.

Verner, J., K.S. McKelvey, B.R. Noon, R.J. Gutiérrez, G.I. Gould, and T.W. Beck. 1992. The 

California spotted owl: a technical assessment of its current status. Gen. Tech. Rep. PSWGTR-133. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest 

Research Station. 285 pp.

Wasser, S.K., K. Bevis, G. King, and E. Hanson. 1997. Noninvasive physiological measures of 

disturbance in the Northern Spotted Owl. Conservation Biology 11(4):1019-1022.

Weller, T.J. and C.J. Zabel. 2001. Characteristics of fringed myotis day roosts in northern California. 

Journal of Wildlife Management 66(3):489-497.

White, P.J., J.J. Borkowski, T. Davis, R.A. Garrott, D.P. Reinhart, and D.C. McClure. 2009. Chapter 

26: Wildlife Responses to Park Visitors in Winter. In Terrestrial Ecology: The Ecology of 

Large Mammals in Central Yellowstone—Sixteen Years of Integrated Field Studies, vol. 3, 

edited by R.A. Garrott, P.J. White, and F.G.R. Watson, 581–601. Elsevier. San Diego, 

California.

Whitaker, J.O. Jr., C. Maser, and L.E. Keller. 1977. Food habits of bats of western Oregon. 

Northwest Scientist 51:46–55.

Whitaker, J.O. Jr., C. Maser, and S.P. Cross. 1981. Food habits of eastern Oregon bats, based on 

stomach and scat analyses. Northwest Scientist 55:281–292.

Williams, P.J., R.J. Gutierrez, and S.A. Whitmore. 2011. Home range and habitat selection of spotted 

owls in the central Sierra Nevada. Journal of Wildlife Management 75(2):333-343.

Woodbridge, B., and C.D. Hargis. 2006. Northern Goshawk inventory and monitoring technical 

guide. USDA Forest Service, WO GTR-71. 63 pp.

Wu, J.X., R.B. Siegel, H.L. Loffland, M.W. Tingley, S.L. Stock, K.N. Roberts, J.J. Keane, J.R. 

Medley, R. Bridgman, and C. Stermer. 2015. Diversity of Great Gray Owl Nest Sites and 

Nesting Habitats in California. Journal of Wildlife Management 79(6):937-947.

Zeiner, D.C., W.F. Laudenslayer, Jr., K.E. Mayer, and M. White, eds. 1990. California's Wildlife. 

Volume III. Mammals. California Statewide Wildlife Habitat Relationship System. 

Department of Fish and Game, The Resources Agency, Sacramento, California. 407 pp.
Over-snow Vehicle Use Designation

Tahoe National Forest

414

Zielinski, W.J. 2014. The forest carnivores: marten and fisher. In: Long, J.W.; Quinn-Davidson, L.; 

Skinner, C.N., eds. Science synthesis to support socioecological resilience in the Sierra 

Nevada and southern Cascade Range. Gen. Tech. Rep. PSW-GTR-247. Albany, CA: U.S. 

Department of Agriculture, Forest Service, Pacific Southwest Research Station: 393-435. 

Chap. 7.1.

Zielinski, W. 2015. Personal communication between William (Bill) Zielinski (Research Ecologist, 

PSW Redwood Sciences Lab) March 26, 2015, with Katherine Malengo regarding potential 

impacts of OSV use on martens and marten den sites in the Sierra Nevada of California.

Zielinski, W.J., K.M. Slauson, and A.E. Bowles, 2008. Effects of off-highway vehicle use on the 

American marten. Journal of Wildlife Management 72(7):1558-1571.

Zielinski, W.J., R.L. Truex, F.V. Schlexer, L.A. Campbell, and C. Carroll. 2005. Historical and 

contemporary distribution of carnivores in forests of the Sierra Nevada, California, USA. 

Journal of Biogeography 32:1385-1407.

Management Indicator Species

California Department of Fish and Game (CDFG). 2005. California Department of Fish and Game 

and California Interagency Wildlife Task Group. California Wildlife Habitat Relationships 

(CWHR) version 8.1. Personal computer program. Sacramento, California. On-Line version. 

http://www.dfg.ca.gov/biogeodata/cwhr/cawildlife.asp. (Accessed: January 3, 2008).

Hawkins, C.P. 2003. Development, evaluation, and application of a RIVPACS-type predictive model 

for assessing the biological condition of streams in Region 5 (California) national forests. 

Completion Report. Western center for Monitoring and Assessment of Fresh Water 

Ecosystems. Utah State University. Logan, Utah 23 pp.

Mayer, K.E., and W.F. Laudenslayer, eds. 1988. A Guide to Wildlife Habitats of California. 

California Department of Forestry and Fire Protection, Sacramento, CA. 166 pp. 

http://www.dfg.ca.gov/biogeodata/cwhr/wildlife_habitats.asp

U.S. Department of Agriculture (USDA Forest Service). 2001. Sierra Nevada Forest Plan 

Amendment Final Environmental Impact Statement. Forest Service, Pacific Southwest 

Region. January 2001. http://www.fs.fed.us/r5/snfpa/library/archives/feis/index.htm

USDA Forest Service. 2006a. Draft - MIS Analysis and Documentation in Project-Level NEPA, R5 

Environmental Coordination, May 25, 2006. Pacific Southwest Region. 3 pp.

USDA Forest Service. 2007a. Record of Decision, Sierra Nevada Forests Management Indicator 

Species Amendment. U.S. Forest Service, Pacific Southwest Region. December 2007. 18 pp.

USDA Forest Service. 2010a. Sierra Nevada Forests Bioregional Management Indicator Species 

(MIS) Report: Life history and analysis of Management Indicator Species of the 10 Sierra 

Nevada National Forests: Eldorado, Inyo, Tahoe, Modoc, Plumas, Sequoia, Sierra, 

Stanislaus, and Tahoe National Forests and the Lake Tahoe Basin Management Unit. Pacific 

Southwest Region, Vallejo, CA. December 2010. 132 pp.
Draft Environment Impact Statement – Volume I

Glossary

Tahoe National Forest

415

Glossary 

Administrative Use Motorized vehicle use vehicle use associated with 

management activities or projects on National Forest land 

administered by the Forest Service or under authorization of 

the Forest Service. Management activities include but are not 

limited to: law enforcement, timber harvest, reforestation, 

cultural treatments, prescribed fire, watershed restoration, 

wildlife and fish habitat improvement, private land access, 

allotment management activities, and mineral exploration 

and development that occur on National Forest land 

administered by the Forest Service or under authorization of 

the Forest Service. 

Area A discrete, specifically delineated space that is smaller, and, 

except for over-snow vehicle use, in most cases much 

smaller, than a ranger ristrict.

Designated Road or Trail or Area A National Forest System road, National Forest system trail, 

or an area on National Forest System lands that is designated 

for over-snow vehicle use pursuant to 36 CFR 212.51 on an 

over-snow vehicle use map (36 CFR 212.1).

Designation of over-snow vehicle use Designation of a National Forest System road, a National 

Forest System trail, or an area on National Forest System 

lands where over-snow vehicle use is allowed pursuant to 

212.81.

Forest road or trail A road or trail wholly or partially within or adjacent to and 

serving the [National Forest System (NFS)] that is 

determined to be necessary for the protection, 

administration, and utilization of the NFS and the use and 

development of its resources (36 CFR 212.1)

Non-motorized use A term used in this document to refer to travel other than that 

defined as motorized. For example, hiking, riding horses, or 

mountain biking. 

Over-snow vehicle (OSV) A motor vehicle that is designed for use over snow and that 

runs on a track or tracks and/or a ski or skis, while in use 

over snow (36 CFR 212.1)

Over-snow vehicle use map A map reflecting roads, trails, and areas designated for oversnow vehicle use on an administrative unit or a ranger 

district of the National Forest System.

Trail A route 50 inches wide or less or a route over 50 inches wide 

that is identified and managed as a trail (36 CFR 212.1).