Prepared for: 

WESTERN FEDERAL LANDS HIGHWAY DIVISION 

610 East Fifth Street, Vancouver, WA 98661 

PRELIMINARY ENGINEERING 

REPORT

Shields River Road Planning Project, MT Park 34(1)

IDIQ Contract No. DTFH7015D00007

Task Order No. 69056719F000031

Sept. 27, 2019 

Prepared by: 

ROBERT PECCIA & 

ASSOCIATES 

Helena, Montana 
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

 September 27, 2019 i

TABLE OF CONTENTS 

Table of Contents ......................................................................................................................... i

List of Tables ............................................................................................................................................. ii

List of Figures ........................................................................................................................................... ii

List of Appendices .................................................................................................................................... iii

Abbreviations/Acronyms .......................................................................................................... iv

1.0. Introduction and Background .............................................................................................. 1

1.1. Study Area ........................................................................................................................................ 1

1.2. Historic Construction and Improvements .......................................................................................... 3

1.3. Current and Planned Projects ........................................................................................................... 3

1.4. Existing Plans and Regulations ........................................................................................................ 3

2.0. Transportation System ......................................................................................................... 5

2.1. Physical Features and Characteristics ............................................................................................. 5

2.1.1. Hydraulics .................................................................................................................................... 5

2.1.2. Bridges ........................................................................................................................................ 5

2.1.3. Culverts ....................................................................................................................................... 6

2.1.4. Maintenance and Operations ...................................................................................................... 8

2.1.5. Roadway Surfacing ..................................................................................................................... 8

2.1.6. Access Points ............................................................................................................................ 11

2.1.7. Right-of-Way ............................................................................................................................. 11

2.1.8. Utilities ....................................................................................................................................... 13

2.1.9. Alternative Transportation Modes ............................................................................................. 13

2.1.10. Recreational Opportunities ...................................................................................................... 13

2.2. Geometric Conditions ..................................................................................................................... 15

2.2.1. Design Criteria ........................................................................................................................... 15

2.2.2. Horizontal Alignment ................................................................................................................. 16

2.2.3. Vertical Alignment ..................................................................................................................... 16

2.2.4. Sight Distance ........................................................................................................................... 17

2.2.5. Clear Zone ................................................................................................................................. 17

2.3. Traffic Conditions ............................................................................................................................ 17

2.4. Safety .............................................................................................................................................. 18

2.4.1. Safety Trends, Contributing Factors, and Crash Clusters ........................................................ 18

2.5. Other Vulnerabilities........................................................................................................................ 20

3.0. Environmental Setting .......................................................................................................23

3.1. Physical Environment ..................................................................................................................... 23

3.1.1. Land Ownership and Land Use ................................................................................................. 23

3.1.2. Soil Resources and Prime Farmland ........................................................................................ 23

3.1.3. Geologic Hazards ...................................................................................................................... 24

3.1.4. Surface Waters .......................................................................................................................... 24

3.1.5. Groundwater .............................................................................................................................. 25

3.1.6. Floodplains and Floodways ....................................................................................................... 25

3.1.7. Wetlands and Waters of the U.S. .............................................................................................. 26

3.1.8. Hazardous Substances ............................................................................................................. 26

3.1.9. Air Quality .................................................................................................................................. 26

3.1.10. Noise ....................................................................................................................................... 26
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 Preliminary Engineering Report 

 September 27, 2019 ii

3.2. Biological Resources ...................................................................................................................... 27

3.2.1. Vegetation ................................................................................................................................. 27

3.2.2. Fish and Wildlife ........................................................................................................................ 27

3.2.3. Threatened and Endangered Species ...................................................................................... 28

3.2.4. Other Species of Concern ......................................................................................................... 28

3.3. Social and Cultural Resources ....................................................................................................... 28

3.3.1. Demographic and Economic Conditions ................................................................................... 28

3.3.2. Recreational Resources ............................................................................................................ 29

3.3.3. Cultural and Historic Resources ................................................................................................ 30

3.3.4. Visual Resources ...................................................................................................................... 30

4.0. Areas of Concern and Consideration ................................................................................31

4.1. Transportation Conditions ............................................................................................................... 31

4.2. Environmental Setting ..................................................................................................................... 32

5.0. Goals and Objectives ........................................................................................................33

6.0. Improvement Options ........................................................................................................35

6.1. Design Typical Sections ................................................................................................................. 35

6.2. Roadway Reconstruction/Rehabilitation ......................................................................................... 37

Segment 1: US 89 to Pinkerton Road (MP 0.0 to 3.8) ........................................................................ 37

Segment 2: Pinkerton Road to Porcupine Road (MP 3.8 to 8.4) ........................................................ 37

Segment 3: Porcupine Road to Hill Road (MP 8.4 to 14.2) ................................................................ 38

Segment 4: Hill Road to Smith Creek Road (MP 14.2 to 15.7) ........................................................... 39

Segment 5: Smith Creek Road to End Project (MP 15.7 to 19.5) ....................................................... 39

6.3. Combined Reconstruction .............................................................................................................. 40

6.4. Summary of Options and Estimated Costs ..................................................................................... 41

7.0. Public Meeting Summary ...................................................................................................43

8.0. Conclusion and Next Steps ................................................................................................44

References ................................................................................................................................45

LIST OF TABLES

Table 2.1: Stream and River Crossings ........................................................................................................ 5

Table 2.2: Bridges in the Study Area ............................................................................................................ 6

Table 2.3: Minimum Recommended Total Roadway Width .......................................................................... 9

Table 2.4: Roadway Surfacing and Pavement Condition ............................................................................. 9

Table 2.5: Access Points ............................................................................................................................. 11

Table 2.6: Geometric Design Criteria .......................................................................................................... 15

Table 2.7: Horizontal Curves Design Speed Met ........................................................................................ 16

Table 2.8: Existing Traffic Volumes ............................................................................................................ 18

Table 6.1: Improvement Options Summary ................................................................................................ 41

LIST OF FIGURES

Figure 1.1: Study Area .................................................................................................................................. 2

Figure 2.1: Bridges and Culverts .................................................................................................................. 7

Figure 2.2: Pavement Condition ................................................................................................................. 10

Figure 2.3: Property Ownership .................................................................................................................. 12

Figure 2.4: Recreational Facilities ............................................................................................................... 14
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

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Figure 2.5: Crash Locations ........................................................................................................................ 19

Figure 2.6: Other Vulnerabilities ................................................................................................................. 22

Figure 6.1: 24-foot Typical Section (Existing) ............................................................................................. 36

Figure 6.2: 28-foot Typical Section (Park County Standards) .................................................................... 36

Figure 6.3: 30-foot Typical Section (AASHTO Standards) ......................................................................... 36

Figure 6.4: Improvement Options ............................................................................................................... 42

LIST OF APPENDICES

Appendix A: Bridge Inspection Reports 

Appendix B: Culvert Inventory 

Appendix C: Horizontal Curves 

Appendix D: Traffic Data 

Appendix E: Environmental Scan 

Appendix F: Preliminary Cost Estimates 

Appendix G: Public Meeting Summary 

Appendix H: Public Comments Received 

 
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

 September 27, 2019 iv

ABBREVIATIONS/ACRONYMS 

AASHTO American Association of State Highway Transportation Officials

ACS American Community Survey 

ADT Average Daily Traffic

ARRA American Recovery and Reinvestment Act 

CIP Capital Improvements Plan 

ERFO Emergency Relief for Federally Owned Roads

ESA Endangered Species Act 

FHWA Federal Highway Administration 

FLAP Federal Lands Access Program 

FPPA Farmland Policy Protection Act 

FWP Fish, Wildlife, and Parks 

GCR General Condition Rating 

MDEQ Montana Department of Environmental Quality 

MDT Montana Department of Transportation 

MP Mile Post 

mph Miles Per Hour

NBI National Bridge Inventory 

NRCS National Resource Conservation Service 

PASER Pavement Surface Evaluation and Rating 

PCB Polychlorinated biphenyls 

SSD Stopping Sight Distance

USFS United States Forest Service 

vpd Vehicles Per Day
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

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PRELIMINARY ENGINEERING REPORT 

1.0. INTRODUCTION AND BACKGROUND 

Shields River Road provides access to over 113,000 acres of the Custer-Gallatin National Forest within the 

Crazy Mountains. The roadway parallels the Shields River which begins in the Crazy Mountains and flows 

62 miles to the confluence of the Yellowstone River east of Livingston. Shields River Road offers scenic 

views of mountain peaks, rivers, and streams. Over the years, several other access points to the national 

forest have been closed because of landowner disputes. This has made the Shields River Road corridor 

the most heavily utilized road by recreationists on the west side of the Crazy Mountains. 

Recognizing the deteriorating conditions of the roadway, and the use as a major access to federal lands, 

the Federal Highway Administration (FHWA), in partnership with Park County and the United States Forest 

Service (USFS), developed this planning study to identify potential improvements to the Shields River Road 

corridor. A key outcome of the study is the development of recommendations intended to address the 

transportation and access needs of roadway users in the study area. The recommendations define the most 

critical needs of the corridor and will help the study partners prioritize and allocate resources to address the 

needs. This study reviews and considers environmental and social issues and aims to reduce planning time 

and minimize construction costs through the demonstration of feasible improvement opportunities. 

The intent of this Preliminary Engineering Report is to analyze roadway conditions, identify areas of 

concern, and develop improvement options for the study corridor. The transportation conditions analysis 

includes a planning level examination of the corridor based on a variety of information sources and field 

reviews. Goals and objectives for Shields River Road are also identified based on a comprehensive review 

of existing and projected transportation conditions. The analysis, together with the stated goals and 

objectives, influenced the development of potential improvement options intended to address the identified 

issues and areas of concern. 

1.1. STUDY AREA

Shields River Road begins at the intersection of US Highway 89 (US 89) North, on the northern end of 

Wilsall, Montana in Park County. Shields River Road extends for approximately 30 miles up to and through 

the Custer-Gallatin National Forest. The study area for the Shields River Road Planning Project 

encompasses a 19.5-mile section of Shields River Road, starting at mile post (MP) 0.0 approximately onequarter mile north of the Town of Wilsall and ending at MP 19.5 near the National Forest Boundary. Figure 

1.1 presents the study area boundary. 

The roadway provides access to the Custer-Gallatin National Forest and offers access to private ranches, 

homes and cabins; trailheads; designated and undesignated dispersed campgrounds; mountain lakes; and 

access to many creeks and drainages popular for fishing and hunting activities. Within the study area, 

Shields River Road is functionally classified as a minor collector. The roadway offers recreational access 

to hiking, biking, fishing, camping, hunting, winter sports, and wildlife viewing opportunities in the CusterGallatin National Forest. Multiple fishing guides, hunting guides, and outfitters operate in the area along 

with permitted commercial firewood and morel mushroom collectors. The use of lands accessed by Shields 

River Road has historically provided substantial tourism traffic and economic subsistence for the rural 

community of Wilsall. 
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

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Figure 1.1: Study Area 

ELK CREEK M UDDYCREEK

POT ER CRE K

SHIELDS RIVER

DEEP CREEK

DAISY DEAN CREEK

COTTONWOOD

RESERVOIR HORSECREEK

SUNLI GHT C R EEK

SOUTH FORK SHIELDS

POTTER

CREEK RD

FLATHEAD CREEK RD

CRAZY BEAR GULCH

SHIELDS RIVER RD

BRIGHT LN

DAISY DEAN RD

ELK CREEK N

SHIELDS RIVER RD

ELK CREEK RD

HORSE CREEK RD

HILL RD

HORSE CREEK RD S

US HIGHWAY 89 N ANDERSON RD

MATHER LN

LODGEPOLE

PI N K E RTON RD

SMITH

CRE K RD

ELK CREEK RD S

PORCUPINE RD

SHY RD

ELK CREEK RD

JORDAN BENCH RD WOODS LN

COAL CAMP RD

OLD FLATHEAD

CREEK RD

19

7

5

3

17

18

15

14

11

8

0

12

10

4

CUSTER

GALLATIN

NATIONAL

FOREST

Wilsall

Begin Project MP 0.0

End Project MP 19.5

89

86 38

25

37

22

36

23

24

26

27

28 Shields River Road

90

Livingston Bozeman Belgrade PARK MEAGHER GALLATIN

SWEET GRASS WHEATLAND

BROADWATER

90

191

287

191

191

191

12

89

12

89

89

89

89

86

84

85

284

1Only mile posts found during field

review are shown. 0 1 2 3 0.5 Miles

Map Legend

Montana State Trust Lands

State of Montana

Study Corridor

Conservation Easement

US Forest Service

National Forest Boundary

Mile Post1
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

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1.2. HISTORIC CONSTRUCTION AND IMPROVEMENTS

The current alignment for Shields River Road was originally constructed in 1955 from MP 0.00 to 14.35. In 

1975, a Montana Emergency Relief Project (ERFO 72(47)) was completed to construct a single-lane 

concrete bridge over Shields River at MP 16.8. In 2009, the Forest Service received funds from the 

American Recovery and Reinvestment Act (ARRA) to implement the Shields River Road and Bridge 

Reconstruction Project. AARA funds were used to complete the following improvements between 2009 and 

2011: 

 Extend the pavement from MP 14.35 to Smith Creek Junction (approximate MP 15.7) with a 26-

foot paved surface; 

 Improve the gravel surface from MP 15.7 to 16.8 and widen to 24 feet of surfacing; 

 Replace the single lane bridge at MP 16.8 with a double lane bridge; and 

 Widen the gravel surfacing from MP 16.8 to Sunlight Road (MP 19.5) to 20 feet. 

1.3. CURRENT AND PLANNED PROJECTS

Park County establishes priorities, long-range programming, scheduling, and funding for infrastructure 

needs through their Capital Improvements Plan (CIP). The 2016-2020 CIP1 includes two road and bridge 

rehabilitation projects on Shields River Road in the long-range 20-year assessment of needs; however, the 

projects are not scheduled for funding in the current 5-year CIP. These projects include: Shields River Road 

Bridges Rehabilitation ($60,000); and Shields River Road Rehabilitation ($8,500,000). Detailed information 

regarding the specifics of these projects is not currently included in the CIP. It is anticipated that the 

recommendations resulting from this Shields River Road Planning Project will be used to update the CIP 

and to help prioritize and obligate future funding. 

1.4. EXISTING PLANS AND REGULATIONS

Several local plans exist with goals and objectives related to the transportation system in the study area. 

The following provides a summary of existing planning documents and regulations relevant to the Shields 

River Road corridor. 

 Gallatin National Forest Land and Resource Management Plan (1987) – The Gallatin National 

Forest Land and Resource Management Plan2, and the accompanying Final Environmental Impact 

Statement 3, guide all-natural resource management activities and establish management 

standards for the Gallatin National Forest. They describe resource management practices, levels 

of resource production and management, and the availability and suitability of lands for resource 

management within the forest, including the Shields River area. These planning efforts resulted in 

significant watershed restoration efforts in the Shields River area in the mid-1990s in which the 

Forest Service obliterated and restored old logging roads to improve water quality. 

 Shields River Road Improvement Decision Notice (2004) – The Shields River Road 

Improvement Decision Notice and Environmental Assessment4 called for improving Shields River 

Road including widening the road to between 24 and 26 feet (two traffic lanes) and laying a gravel 

surface on the Forest Service section; replacing the Deep Creek bridge; constructing a parking 

area with an accessible toilet at the junction of Shields River Road and Sunlight Road; and 

relocating gates closer to the parking area at Sunlight Road. Environmental effects were 

considered, and the decision was made to proceed with improvements based on a Finding of No 

Significant Impact report by the USFS. Major roadwork on a 5.6-mile section of Shields River Road 

was performed following the release of the Decision Notice. 
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 Preliminary Engineering Report 

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 Gallatin National Forest Travel Management Plan (2006) – The Gallatin National Forest Travel 

Management Plan Record of Decision5 developed and analyzed several alternatives for managing 

public access and travel within the Gallatin National Forest. The report identified a preferred 

alternative and detailed the anticipated changes to public road access and modifications to the 

roads, trails, and open spaces accessible to cars, ATVs, motorcycles, and snowmobiles. 

 Park County Active Transportation Plan (2016) – The Park County Active Transportation Plan6

is a consolidation of two existing plans – the Park County Park Plan (2007) and the Livingston/Park 

County Trails Plan (2006). Through the Active Transportation Plan, Park County and the Parks and 

Recreation Board aim to serve the community through four priority areas: 1) healthy and safe 

alternative transportation promotion; 2) parks, trails, and recreation network opportunities; 3) 

effective collaboration and management; and 4) positive economic competitiveness. The 

Livingston/Park County Trails Plan previously proposed a 21-mile long pathway through the Shields 

Valley. Through the recent planning efforts, the public identified the Shields Valley as a priority for 

active transportation. The Plan recommends Shields River Road as a proposed active 

transportation route. A large multi-use park is also recommended in the Shields Valley. 

 Park County Capital Improvements Plan (2016) – The Park County Capital Improvements Plan1

establishes long-term goals for maintaining, improving or financing new capital improvement 

projects and/or capital equipment over the course of the next five years. This document is utilized 

to assist county leaders with project planning, financing, and determining the overall needs of the 

population. No projects on Shields River Road were scheduled in the CIP for funding over the next 

five years. However, two projects – Shields River Road Rehabilitation ($8,500,000) and Shields 

River Road Bridges Rehabilitation ($60,000) – were included in the long-range 20-year 

assessment. 

 Park County Growth Policy (2017) – The Park County Growth Policy7 identifies and seeks to 

address key social, physical, environmental, economic, and land use issues facing Park County. 

Two goals relating to transportation in the county are identified under the “Key Issues: 

Infrastructure” section: Goal 10 is to create a system of interconnected trails; Goal 11 is to provide 

for a safe and efficient county road network. Land use and development goals are also defined and 

may influence future growth in the Shields River Road area. 

Land use policies and development regulations in the study area are governed principally by Park County. 

Within the National Forest boundary, land use policies and regulations are dictated by the 1987 Land and 

Resource Management Plan, as amended. Since the entire study area falls within County jurisdiction, it is 

anticipated that projects brought forward in this planning study would be subject to County regulations. 

However, coordination among federal, state, and local agency staff would be an essential component of 

any projects that may arise. 
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

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2.0. TRANSPORTATION SYSTEM 

The following analysis of transportation conditions includes a planning level examination of the corridor 

based on existing and historic traffic data, vehicle crash history, field measurements and observations, 

roadway as-built plans, aerial imagery, geographic information system data, and input from local 

stakeholders. This analysis was used to identify areas of concern for the Shields River Road corridor. 

2.1. PHYSICAL FEATURES AND CHARACTERISTICS

Shields River Road connects the town of Wilsall to the Crazy Mountains. The road is paved from its 

beginning at Montana Highway 89 to approximately MP 15.8 at Smith Creek Road. The road is gravel from 

this point to its end, with the exception of a short section of asphalt at the bridge at MP 16.8. The lands 

along Shields River Road are predominantly agricultural in use. The road consists of generally level terrain 

with occasional hills and steep side slopes along the Shields River. 

2.1.1. Hydraulics 

Shields River Road generally parallels the Shields River within the study area. For approximately one mile, 

the roadway also parallels Flathead Creek. For an approximate 2.5-mile segment between Elk Creek West 

Road and Coal Camp Road, Shields River Road also parallels Porcupine Creek and one of its unnamed 

tributaries. Throughout the study area, Shields River Road crosses several streams, irrigation canals, and 

ditches. Table 2.1 presents the major stream crossed by Shields River Road and their approximate location. 

The locations of the streams are also displayed in Figure 2.1. 

Table 2.1: Stream and River Crossings 

Name Approximate Location (MP) Crossing Structure 

Flathead Creek 0.3 Bridge 

Shields River 3.7 Bridge 

Porcupine Creek 7.6 Culvert 

Shields River 14.1 Bridge 

Shields River 16.8 Bridge 

South Fork Shields River 17.5 Culvert 

Mill Creek 18.1 Culvert 

2.1.2. Bridges 

Bridge conditions are determined using the National Bridge 

Inventory (NBI) general condition ratings (GCR). The GCRs 

are used to describe the existing bridge as compared to its 

as-built condition. The material used, as well as the physical 

condition of the deck, superstructure, and substructure of 

the bridge are considered in the rating. GCRs are given a 

numerical rating ranging from 0 (failing condition) to 9 

(excellent condition) as described in the FHWA Coding 

Guide8. 

The bridge condition is classified based on 23 CFR 

490.409 9. When the minimum GCR of the deck, 

superstructure, and substructure is 7, 8, or 9, the bridge is 

classified as “good”. When the minimum GCR is either 5 or 

6 the bridge is classified as “fair”. If the minimum GCR is 4 

There are four bridges in the study area. All four 

bridges are in fair or good condition. 
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

 September 27, 2019 6

or below the bridge is classified as “poor”. One of the bridges has a condition of “good”, which indicates 

that it is a candidate for continued preservation and cyclic maintenance; two of the bridges have a condition 

of “fair”, indicating that they may be candidates for preservation and condition-based maintenance; the 

fourth bridge was recently replaced and has not been assessed by NBI standards but is assumed to be in 

“good” condition. Detailed bridge inspection reports are available in Appendix A.

The Montana Department of Transportation (MDT) Bridge Design Standards10 require off-system bridges 

to have a minimum roadway width of 28 feet unless the county has different standards or if the road has 

very low volume and a single lane bridge (16-foot width) is adequate. MDT standards allow an existing 

bridge to remain in place if it is 24 feet or greater in width. Park County Transportation Standards11

recommend that bridges with average daily traffic (ADT) of 100 vehicles per day (vpd) or more have a 

minimum width of 24 feet. Bridges with ADT of less than 100 vpd should have a minimum width of 14 feet. 

All bridges within the study area have acceptable widths based on these standards. 

In addition to the condition ratings and bridge specifications, a bridge sufficiency rating is listed. FHWA 

uses the sufficiency rating to indicate the sufficiency of a bridge to remain in service. A score of 80 or less 

makes a bridge eligible for rehabilitation, and a score of 50 or less makes a bridge eligible for replacement. 

All bridges in the study area are rated sufficient and are therefore not eligible for rehabilitation or 

replacement. 

The American Association of State Highway Transportation Officials (AASHTO) Standard Specifications for 

Highway Bridges12 identifies design vehicle loads. Most bridges in the United States were designed to 

accommodate either an H15 or HS20 loading. The three assessed bridges have design loads of HS15 

which represents a two-axle single unit truck weighing 15 tons. According to AASHTO standards for 

collector roadways, bridges to remain in place must have a design loading capacity of HS15 or better. All 

of the bridges in the study area have adequate design loading capacities based on this standard. 

Figure 2.1 shows the locations of the four bridges along the study corridor while Table 2.2 shows the 

existing conditions of the structures. 

Table 2.2: Bridges in the Study Area 

Structure 

No. 

Location 

(MP) 

Feature 

Crossed 

Year 

Built 

Curb to Curb 

Width (ft) 

Length 

(ft) 

Bridge 

Condition 

Sufficiency 

Rating 

Design 

Load 

3808 0.3 Flathead Creek 1955 24.2 52 Fair 90.6 HS15 

3809 3.7 Shields River 1955 24.0 70.7 Fair 87.9 HS15 

3810 14.1 Shields River 1957 24.0 25 Good 88.3 HS15 

N/A 16.8 Shields River 2010 28.5* 70* Good* N/A N/A 

* Estimated during field review. 

2.1.3. Culverts 

A total of 70 culverts were identified during the field review. Of those culverts, 17 had a diameter of 30 

inches or more. Fifty-five of the culverts were in fair or good condition. Three stock passes were also 

identified within the study area, two of which are in fair condition and one is in good condition. Appendix B

contains an inventory of each drainage structure and lists the specification and condition of each culvert. 

Figure 2.1 show the locations of the culverts inventoried. All data contained in the appendices were 

collected during field review and may differ from data in inspection reports compiled by Park County and/or 

the Forest Service. This analysis does not include a capacity assessment of the culverts nor does it examine 

whether the culverts pass aquatic organisms. 
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

 September 27, 2019 7

Figure 2.1: Bridges and Culverts Service Layer Credits: Sources: Esri, USGS, NGA, NASA, CGIAR, N Robinson, NCEAS, NLS, OS, NMA,

ELK CREEK M UDDYCREEK

POT ER CRE K

SHIELDS RIVER

DEEP CREEK

DAISY DEAN CREEK

COTTONWOOD

RESERVOIR HORSECREEK

SUNLI GHT C R EEK

SOUTH FORK SHIELDS

POTTER

CREEK RD

FLATHEAD CREEK RD

CRAZY BEAR GULCH

SHIELDS RIVER RD

BRIGHT LN

DAISY DEAN RD

ELK CREEK N

SHIELDS RIVER RD

ELK CREEK RD

HORSE CREEK RD

HILL RD

HORSE CREEK RD S

US HIGHWAY 89 N ANDERSON RD

MATHER LN

LODGEPOLE

PI N K E RTON RD

SMITH

CRE K RD

ELK CREEK RD S

PORCUPINE RD

SHY RD

ELK CREEK RD

JORDAN BENCH RD WOODS LN

COAL CAMP RD

OLD FLATHEAD

CREEK RD

19

7

5

3

17

18

15

14

11

8

0

12

10

4

Wilsall

89

86 38

25

37

22

36

23

24

26

27

28 EL K CRE EK

SOUTH F O RK

LENA CREEK

SLIPPERY CREEK

SH IELDS RIVER

COLECRE K

NORTH FORK HORSE CREEK

MILL CREEK MIDDLE FORK LENA CREEK

COT ONWO D CRE K

SHEILDSCA NYON

NORTH FORK DAISY DEAN CREEK DAISY DEAN CREEK

DEEP CREEK

SUNLIGHT CRE K

LENA CREEK

TRESPAS CRE K

SOUTH FORK ELK CREEK

ANTELOPE CRE K HORSE CREEK

MIDDLE FORK

PORCUPINE CRE K

SMIT H CR E K

SOUTH FORK DAISY DEAN CREEK

LODGEPOLE CRE K

CRANDAL CRE K

INDIAN CREEK

KAVANAUGH CREEK

PORCUPINE CREEK

MEADOW CREEK

S OUTH FORK S HIELDS RIVER

DRY CREEK

GOAT CREEK

FLATHEA D

C REEK

BEN ET CREEK

SOUTH FOR K HORSE CREEK

BASIN CREEK

PAULINE CREEK MIDDLE FORK HO RSE CREEK

SERRET CREEK

LITTLE COTTONWO OD CREEK

NORTH FORK LENA CREEK MYERS DITCH

HORSE CAMP DITC H

BIG CAN AL

NORTH FORK ELK CREEK

0 1 2 3 0.5 Miles

Map Legend

2As determined during field review. 1Only mile posts found during field

review are shown.

River/Stream

Canal/Ditch

Mile Post1 Study Corridor

Unknown

Culvert (Condition)2 Good

Fair

Wooden Poor

Bridge (Type)

Concrete
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 Preliminary Engineering Report 

 September 27, 2019 8

2.1.4. Maintenance and Operations 

Park County is responsible for maintenance of Shields River Road between US 89 (MP 0.0) and the 

National Forest Boundary (MP 19.5). The roadway is maintained by the USFS past MP 19.5. Travel 

restrictions exist on the portion of road maintained by the USFS as documented in the Motor Vehicle Use 

Map Custer Gallatin National Forest13. From MP 0.0 to 19.5 the road is open to highway legal vehicles yearround; from MP 19.5 to 26.9 the roadway is open to highway legal vehicles between June 16th and 

December 1st; and beyond MP 26.9 the roadway is open to all wheeled, non-tracked vehicles during the 

same dates. 

According to the Park County Road Maintenance Map14, the roadway is designated as a “School Bus 

Route” between MP 0.0 and 11.8 and receives first priority for winter maintenance. From MP 11.8 to 16.9, 

Park County designates the roadway as Regular Maintenance and as having second priority for winter 

maintenance. For the remainder of the study corridor (MP 16.9 to 19.5) the roadway is designated as 

Seasonal Maintenance and is not scheduled for winter maintenance, however, Park County may maintain 

this section depending on the occupancy of the residences beyond Smith Creek Road. 

2.1.5. Roadway Surfacing 

Shields River Road is paved between MP 0.0 and 

MP 15.7 at the intersection with Smith Creek Road. 

The remaining portion of the roadway is gravel, 

with the exception of a short segment at the bridge 

near MP 16.8. Existing roadway widths were 

documented during field review and were 

measured from edge of pavement to edge of 

pavement or edge of roadway for gravel sections. 

Measurements were taken approximately every 

half mile or when notable changes in roadway 

width were observed. Roadway widths ranged 

from approximately 22 to 29 feet, with a typical 

width of 24 feet. Table 2.4 shows the existing 

roadway width measurements. 

The AASHTO Policy on Geometric Design of Highways and Streets (Greenbook) 15 recommends a 

minimum travel way width of 22 feet with 4-foot shoulders on each side (for a minimum roadway width of 

30 feet) to meet standards for public use based on traffic patterns and volumes. Exceptions to standards 

are allowed based on topographic constraints, environmental factors, etc., as approved by the road owner 

and maintainer. These standards are applicable to rural collectors with 400 to 2,000 vpd. However, the 

Greenbook states that alternate design criteria may be considered for minor collectors that carry 2,000 vpd 

or fewer in accordance with the AASHTO Guidelines for Geometric Design of Very Low-Volume Local 

Roads16. The Very Low-Volume Local Roads guidance recommends roadway widths ranging from 18 to 26 

feet for new construction of roadways depending on design speed and functional subclass. The guidance 

also states that the cross-section widths of existing roads need not be modified except in those cases where 

there is evidence of site-specific safety problems. 

Park County Transportation Standards also provide area specific guidance for roadway design. A typical 

asphalt paved road is recommended to have a minimum of two 12-foot travel lanes with 2-foot shoulders. 

A typical gravel surfaced road is recommended to have a minimum of 12-foot travel lanes and an overall 

roadway width of 24 feet. Table 2.3 summarizes the various requirements for roadway width based on 

these resources. 

The first 15.7 miles of Shields River Road are paved; the 

remaining 3.8 miles are gravel surfaced. The majority of the 

pavement is in deteriorating condition. 
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

 September 27, 2019 9

Table 2.3: Minimum Recommended Total Roadway Width 

Standard 

Design Speed (mph) 

45 50 55 60 

AASHTO Greenbook* 30 30 30 30 

AASHTO Very Low Volume Local Roads

Minor Access 20 20 -- -- 

Recreational and Scenic 20 20 22 -- 

Agricultural Access 24 26 -- -- 

Park County Transportation Standards

Paved 28 28 28 28 

Gravel 24 24 24 24 

*Based on design volume of 400 to 2,000 vpd. 

Pavement condition was also assessed as part of the field review process. A windshield survey of the 

roadway was performed to assess the existing surfacing condition. The evaluation was completed using 

methods and standards defined in the Pavement Surface Evaluation and Rating (PASER) documents. 

Based on this assessment, the first 14 miles of the roadway has asphalt conditions in fair or worse 

conditions, some areas of which are failing. Physical deficiencies observed during the PASER evaluation 

of the road include transverse and longitudinal cracking, alligator cracking, potholing, flushing, rutting, 

distortion, edge erosion, and failing patches. The recently paved portion between MP 14.0 and the gravel 

section (MP 15.8) is in good or very good condition. The gravel segment is also generally in good condition. 

Table 2.4 includes the PASER ratings taken at half-mile increments or where there was a change in 

surfacing for the roadway. Existing surfacing condition is also shown in Figure 2.2. 

Table 2.4: Roadway Surfacing and Pavement Condition 

Begin 

(MP) 

End 

(MP) 

Width 

(ft) 

Surface 

Type PASER Rating 

Begin 

(MP) 

End 

(MP) 

Width 

(ft) 

Surface 

Type PASER Rating 

0.0 0.5 30.5 Paved 3 Poor 10.5 11.0 24.0 Paved 4 Fair 

0.5 1.0 24.5 Paved 4 Fair 11.0 11.5 24.5 Paved 3 Poor 

1.0 1.5 24.0 Paved 3 Poor 11.5 12.0 24.0 Paved 3 Poor 

1.5 2.0 24.0 Paved 2 Very Poor 12.0 12.5 26.0 Paved 2 Very Poor 

2.0 2.5 24.0 Paved 2 Very Poor 12.5 13.0 25.0 Paved 1 Failing 

2.5 3.0 22.5 Paved 3 Poor 13.0 13.5 25.5 Paved 1 Failing 

3.0 3.5 24.0 Paved 3 Poor 13.5 14.0 25.0 Paved 4 Fair 

3.5 4.0 25.0 Paved 3 Poor Average MP 0.0 to 14.0 3 Poor 

4.0 4.5 24.0 Paved 2 Very Poor 14.0 14.5 25.0 Paved 7 Good 

4.5 5.0 25.0 Paved 3 Poor 14.5 15.0 25.0 Paved 8 Very Good 

5.0 5.5 24.5 Paved 2 Very Poor 15.0 15.5 24.0 Paved 7 Good 

5.5 6.0 24.0 Paved 3 Poor 15.5 15.8 24.0 Paved 8 Very Good 

6.0 6.5 23.0 Paved 2 Very Poor Average MP 14.0 to 15.8 7 Good 

6.5 7.0 23.5 Paved 3 Poor 15.8 16.5 25.0 Gravel 4 Good 

7.0 7.5 24.0 Paved 3 Poor 16.5 16.8 29.0 Gravel 4 Good 

7.5 8.0 24.0 Paved 3 Poor 16.8 16.9 24.0 Paved 8 Very Good 

8.0 8.5 24.5 Paved 3 Poor 16.9 17.5 22.0 Gravel 4 Good 

8.5 9.0 24.5 Paved 2 Very Poor 17.5 18.0 24.0 Gravel 3 Fair 

9.0 9.5 24.5 Paved 3 Poor 18.0 18.5 25.0 Gravel 4 Good 

9.5 10.0 24.0 Paved 4 Fair 18.5 19.0 23.0 Gravel 4 Good 

10.0 10.5 24.5 Paved 4 Fair 19.0 19.5 23.5 Gravel 4 Good 

 Average MP 15.8 to 19.5* 4 Good 

* Excludes MP 16.8 to 16.9 
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

 September 27, 2019 10

Figure 2.2: Pavement Condition 

ELK CREEK M UDDYCREEK

POT ER CRE

K

SHIELDS RIVER

DEEP CREEK

DAISY DEAN CREEK

COTTONWOOD

RESERVOIR HORSECREEK

SUNLIGHT CR EEK

SOUTH FORK SHIELDS

POTTER

CREEK RD

FLATHEAD CREEK RD

CRAZY BEAR GULCH

SHIELDS RIVER RD

BRIGHT LN

DAISY DEAN RD

ELK CREEK N

SHIELDS RIVER RD

ELK CREEK RD

HORSE CREEK RD

HILL RD

HORSE CREEK RD S

US HIGHWAY 89

N ANDERSON RD

MATHER LN

LODGEPOLE

PI N K ERTON RD

SMITH

CRE K RD

ELK CREEK RD S

PORCUPINE RD

SHY RD

ELK CRE K RD

JORDAN BENCH RD WOODS LN

COAL CAMP RD

OLD FLATHEAD

CREEK RD

19

7

5

3

17

18

15

14

11

8

0

12

10

4

Wilsall

End of Pavement MP 15.8

89

86 38

25

37

22

36

23

24

26

27

28

1Only mile posts found during field review

are shown. 2Determined through windshield survey. 0 1 2 3 0.5 Miles

Map Legend

PASER2Good

Fair

Poor

Very Poor

Failing

Mile Post1 Very Good
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

 September 27, 2019 11

2.1.6. Access Points 

Access points along Shields River Road were identified during the field review and from aerial photography. 

There are approximately 81 access points along the corridor. Private approaches, farm accesses, pullout 

areas, and public roads were all considered access points. The access points were sporadic along the 

corridor. On average, there were 4.2 access points per mile along the corridor. Table 2.5 provides a 

summary of access points grouped into mile-long segments. 

Table 2.5: Access Points 

Begin 

(MP) 

End 

(MP) 

Segment 

Length (mi) Approaches 

Density 

(app/mi) Description 

0.0 3.8 3.8 16 4.2 Beginning of Study area (US 89) to Pinkerton Road 

3.8 8.4 4.6 15 3.3 Pinkerton Road to Porcupine Road 

8.4 15.7 7.3 35 4.7 Porcupine Road to Smith Creek Road 

15.7 19.5 3.8 15 3.9 Smith Creek Road to end of Study Area – Gravel 

section 

Total 19.5 81 4.2 Entire Corridor 

2.1.7. Right-of-Way 

Park County Transportation Standards 

recommend a minimum of 60 feet of right-ofway for both asphalt and gravel roads within 

County jurisdiction. Most of the land 

surrounding Shields River Road is privately 

owned. A section of the roadway, between 

approximate MP 12.5 and 14.5, is privately 

owned but a conservation easement held by 

Gallatin Valley Land Trust exists on the land. 

Based on right-of-way plans from the original 

road construction, Park County holds at least 

40 feet of right-of-way on each side of the 

Shields River Road centerline through the first 

14.35 miles of the roadway. Right-of-way plans 

for the last 4.65 miles of Shield River Road are 

unavailable. Figure 2.3 shows the public and 

private land ownership within the study area. 

Park County holds at least 40 feet of right of way on each side of the 

Shields River Road centerline from MP 0.0 to 14.35. Park County 

design standards recommend a minimum of 60 total feet of right-ofway.
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

 September 27, 2019 12

Figure 2.3: Property Ownership 

ELK CREEK M UDDYCREEK

POT ER CRE K

SHIELDS RIVER

DEEP CREEK

DAISY DEAN CREEK

COTTONWOOD

RESERVOIR HORSECREEK

SUNLI GHT C R EEK

SOUTH FORK SHIELDS

POTTER

CREEK RD

FLATHEAD CREEK RD

CRAZY BEAR GULCH

SHIELDS RIVER RD

BRIGHT LN

DAISY DEAN RD

ELK CREEK N

SHIELDS RIVER RD

ELK CREEK RD

HORSE CREEK RD

HILL RD

HORSE CREEK RD S

US HIGHWAY 89 N ANDERSON RD

MATHER LN

LODGEPOLE

PI N K E RTON RD

SMITH

CRE K RD

ELK CREEK RD S

PORCUPINE RD

SHY RD

ELK CREEK RD

JORDAN BENCH RD WOODS LN

COAL CAMP RD

OLD FLATHEAD

CREEK RD

19

7

5

3

17

18

15

14

11

8

0

12

10

4

Wilsall

89

86 38

25

37

22

36

23

24

26

27

28

0 1 2 3 0.5 Miles

Map Legend

1Only mile posts found during field

review are shown.

Private Land

Conservation Easement

Local Government

County Government

US Forest Service

State of Montana

Montana State Trust Lands

Mile Post1 Study Corridor
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

 September 27, 2019 13

2.1.8. Utilities 

Several utilities are located within the study area including underground and overhead power along with 

underground fiber optics. The utilities exist along both sides of the roadway and cross the road both 

underground and above ground in several locations. All utilities are generally located within the roadway 

right-of-way. 

2.1.9. Alternative Transportation Modes 

The Park County Active Transportation Plan designates Shields River Road as a proposed active 

transportation route. There are currently no dedicated bicycle or pedestrian facilities along the study 

corridor. Biking, walking, and running activities along the corridor are reported and could increase with 

additional use in the future. There are also no transit services on the study corridor. 

2.1.10. Recreational Opportunities 

Shields River Road provides access to the 

Custer-Gallatin National Forest, public-use 

cabins, trailheads, campgrounds, and other 

popular recreation areas. The roadway, along 

with lands accessed by the roadway, are used 

for a variety of recreational activities including 

bicycling, running, hiking, wildlife viewing, ATV 

and motorcycle activities, horseback riding, 

fishing, hunting, camping, snowmobiling, crosscountry skiing, and snowshoeing. Primary 

destinations accessed by Shields River Road 

include: 2 USFS cabins (Crandall Creek and 

Porcupine Creek); 12 vacation-rental-by-owner 

facilities; 8 designated dispersed campsites; 

over 30 undesignated dispersed campsites; 12 

day-use sites; 6 developed trailheads; 24 trail 

systems; 9 designated ATV routes; numerous 

mountain lakes; and several streams. From 

some of the camping sites, historic interpretation 

and trailheads can be accessed. Figure 2.4 

shows the locations of the various recreational 

opportunities near the study area. 

A desire has been expressed to construct a parking lot at the 

intersection of Shields River Road and Smith Creek Road to 

facilitate winter recreation in the Custer-Gallatin National Forest. 
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

 September 27, 2019 14

Figure 2.4: Recreational Facilities 

ELK CREEK M UDDYCREEK

POT ER CRE K

SHIELDS RIVER

DEEP CREEK

DAISY DEAN CREEK

COTTONWOOD

RESERVOIR HORSECREEK

SUNLI GHT C R EEK

SOUTH FORK SHIELDS

POTTER

CREEK RD

FLATHEAD CREEK RD

CRAZY BEAR GULCH

SHIELDS RIVER RD

BRIGHT LN

DAISY DEAN RD

ELK CREEK N

SHIELDS RIVER RD

ELK CREEK RD

HORSE CREEK RD

HILL RD

HORSE CREEK RD S

US HIGHWAY 89 N ANDERSON RD

MATHER LN

LODGEPOLE

PI N K E RTON RD

SMITH

CRE K RD

ELK CREEK RD S

PORCUPINE RD

SHY RD

ELK CREEK RD

JORDAN BENCH RD WOODS LN

COAL CAMP RD

OLD FLATHEAD

CREEK RD

19

7

5

3

17

18

15

14

11

8

0

12

10

4

Porcupine Cabin

Crandell Creek Cabin CUSTER

GALLATIN

NATIONAL

FOREST

Wilsall

89

86 38

25

37

22

36

23

24

26

27

28

0 1 2 3 0.5 Miles

Map Legend

1Only mile posts found during field

review are shown.

Trailhead

Picnic Area

Forest Service Facility

Campground

National Forest Boundary

Forest Service Trail

Mile Post1 Study Corridor
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

 September 27, 2019 15

2.2. GEOMETRIC CONDITIONS

Existing roadway geometrics were evaluated and compared to current standards. As-built drawings were 

available for the first 14.35 miles from when the road was originally constructed. Existing geometric 

conditions were determined based on these as-builts from 1954. Note that the existing alignment may differ 

from the original alignment as reconstruction and spot improvements may have occurred over the past 65 

years. For the remaining 5 miles of the study corridor, as-built drawings are unavailable, so field review and 

aerial photography were used to document existing roadway geometrics. 

2.2.1. Design Criteria 

The AASHTO Greenbook specifies general design principles and controls that determine the overall 

operational characteristics of the roadway. Of critical importance to determining design standards is the 

design speed. AASHTO’s manuals provide guidance for design speed based on facility and operating 

characteristics; however, some judgment is necessary. A facility’s design speed and its operating speed 

may differ. The design speed is a selected speed used to determine the various geometric design features 

of the roadway. The operating speed is the highest overall speed at which a driver may travel on a given 

section of roadway under favorable weather conditions and prevailing traffic conditions without at any time 

exceeding the safe speed as determined by the design speed. 

Table 2.6 lists current design standards for rural collector routes according to AASHTO design criteria. The 

highway design criteria depend on terrain, area context (i.e., urban or rural), and daily traffic volumes. The 

projected traffic volumes for the corridor are between 300 and 400 vpd. Based on the terrain and area 

context definitions provided by AASHTO, the study corridor appears to be of rural context under level terrain 

with some areas of rolling terrain. This correlates to a design speed ranging from 40 miles per hour (mph) 

to 50 mph. However, the speed limit throughout the corridor is 55 mph. AASHTO recommends, where 

practical, design speeds greater than those given in the Greenbook be considered. Given the higher speed 

limit, a design speed of 60 mph with associated design standards was assumed for the purposes of this 

report. A final determination of design speed will ultimately be made during project development. 

Table 2.6: Geometric Design Criteria 

Design Element 

Design Criteria 

0 to 400 vpd 400 to 2000 vpd Over 2000 vpd Design Control Design Speed 

Level 40 mph 50 mph 60 mph 

Rolling 30 mph 40 mph 50 mph 

Mountainous 20 mph 30 mph 40 mph Alignment Elements 

Design Speed 40 mph 50 mph 60 mph 

Maximum Grade 

Level 7% 6% 5% 

Rolling 8% 7% 6% 

Mountainous 10% 9% 8% 

Vertical Curvature (K-value) 

Crest 44 84 151 

Sag 64 96 136 

Stopping Sight Distance (SSD) 305 425 570 

Radius 444 758 1,200 
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

 September 27, 2019 16

2.2.2. Horizontal Alignment 

Elements comprising horizontal alignment include curvature, superelevation (i.e., the bank on the road), 

and sight distance. These horizontal alignment elements influence traffic operation and safety and relate 

directly to the design speed of the corridor. AASHTO’s design standards for horizontal curves are defined 

in terms of curve radius, and they vary based on design speed. For a 60-mph design speed, the minimum 

recommended radius is 1,200 feet with a minimum stopping sight distance (SSD) of 570 feet. 

Appendix C summarizes each horizontal curve identified in the as-built plans for the study corridor. Asbuilt plans are only available for the first 14.35 miles of the corridor. A determination of whether the curve 

met standards was decided based on the design criteria discussed previously. The controlling design 

criteria for the horizontal curves are radius and SSD. SSD for a horizontal curve is evaluated based on the 

ability to see through the inside of the corner. Minimum sight obstruction distances were calculated based 

on the criteria contained in the AASHTO Greenbook. The minimum sight obstruction distance is measured 

from the center of the inside travel lane and defines the area that should be clear of obstructions to allow 

for the recommended SSD. 

Based on review of as-built plans, there are 29 horizontal curves along the first 14.35 miles of the study 

area corridor. Of these curves, 14 do not meet 60-mph design standards for horizontal curvature. For the 

remaining portion of the corridor, horizontal curve radii were measured based off aerial photography. Only 

those curves with design speeds less than 60 mph were identified. A total of 13 horizontal curves were 

identified along this segment with design speeds less than 60 mph. Several of these curves, although 

substandard in radius, are very short in length and are not necessarily a concern for sight distance. Table 

2.7 summarizes the horizontal curves and the design speed that each curve meets. 

Table 2.7: Horizontal Curves Design Speed Met 

Design Speed 

Met (mph) 

MP 0.0 – 14.35 Design Speed 

Met (mph)* 

MP 14.35 – 19.5 

Number of Curves Percent of Curves Number of Curves* 

Total ≥ 60 15 52% Total ≥ 60 ** 

55 3 10% 50 2 

50 9 31% 45 1 

45 1 3% 40 5 

40 0 0% 35 3 

35 1 3% ≤ 30 2 

Total ≤ 60 14 48% Total ≤ 60 13 

* Estimated based on aerial photography 

** Not determined 

2.2.3. Vertical Alignment 

Vertical alignment is a measure of the elevation change of a roadway. The length and steepness of grades 

directly affect the operational characteristics of the roadway. The controlling design limits for vertical curves 

are SSD, vertical curvature (K-value), and maximum grade. Vertical curves can be placed into two 

categories: crest and sag. A crest curve is created at the top of a hill or when the grade decreases. 

Conversely, a sag curve occurs at the bottom of a hill or when the grade increases. 

Park County Transportation Standards state that the maximum allowable grade of new roads is 10 percent. 

Improvements to existing facilities should be in accordance with AASHTO standards which state that the 

maximum allowable grades range between 5 and 10 percent depending on design speed and terrain. No 

vertical profile data was available for the study corridor. The existing as-builts did not include roadway 
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

 September 27, 2019 17

profiles or vertical curve information. During the field review three vertical curves were visually observed to 

have poor sight distances. These locations are at approximately MP 8.0, 17.5, and 18.1. 

2.2.4. Sight Distance 

Sight distance is the length of roadway visible to a driver and is influenced by the geometry of the road 

(horizontal or vertical curves) and obstacles alongside the road. Sight distance is commonly defined in three 

ways: passing sight distance, stopping sight distance, and intersection sight distance. In general, the driver 

of a vehicle should have an unobstructed view and enough distance to perceive, react, and safely stop for 

or avoid approaching vehicles and other hazards. 

Although roadway geometrics are not available, it was observed during the field review that there are two 

locations along Shields River Road where trees and other vegetation may inhibit the driver’s sight distance. 

These are located at approximately MP 11.3 and 13.8. There were also five locations where the roadway 

geometrics limited the sight distance of the observers. Of these five locations, two were horizontal curves 

(MP 19.3 and 19.4), two were vertical curves (MP 17.5 and 18.1), and one was a compound 

horizontal/vertical curve (MP 8.0). 

2.2.5. Clear Zone 

The FHWA defines a clear zone as the unobstructed, 

traversable roadside area that allows a driver to stop 

safely or regain control of a vehicle that has left the 

roadway. The width of the clear zone is based on 

traffic volumes, speeds, and slopes. Clear roadsides 

consider both fixed objects and terrain that may cause 

vehicles to rollover. Due to the low ADT and rural 

context of Shield River Road, a clear zone of 7 to 10 

feet with recoverable slopes is recommended. No 

cross-sectional data were available to evaluate clear 

zone distances. 

2.3. TRAFFIC CONDITIONS

Park County staff estimate traffic volumes on Shields River Road based on the number of year-round 

residences in the area which are only accessible by Shields River Road, Forest Service cabin occupancy 

rates, and permitting information for grazing and lodging in the area. Based on these factors, the current 

ADT on Shields River Road is estimated to be 245 vpd. During the peak season, Park County Staff 

estimates there are 340 vpd traveling on Shields River Road. It is also estimated that approximately eight 

percent of the traffic volumes are heavy trucks, including agriculture and logging vehicles. 

To supplement the Park County traffic estimates, traffic data were collected between July 2 and July 9, 

2019. This week was selected to gather data during a typically busy recreational week. Road tubes were 

set up at four sites along the corridor at approximately MP 0.5, 5.2, 14.3, and 19.3. Table 2.8 presents the 

ADT data collected at these sites. Due to the holiday nature of the time period studied, the data were 

separated between weekday and weekend traffic. As can be seen in the data, there is more traffic on the 

weekend likely due to recreational use. 

In some locations, vegetation within the clear zone limits 

sight distance for drivers. This can hinder the ability of a 

driver to see oncoming traffic. 
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

 September 27, 2019 18

Table 2.8: Existing Traffic Volumes 

Location (MP) Weekday ADT (vpd) Weekend ADT (vpd) Combined Total ADT (vpd) 

0.5 285 311 295 

5.2 195 213 201 

14.3 151 197 162 

19.3 39 72 49 

From these data it can be seen that traffic decreases with distance along the Shields River Road corridor. 

The site at MP 14.3 was selected to determine how much traffic is using Smith Creek Road, likely for 

recreational access. Based on the difference between the volumes measured at MPs 14.3 and 19.3, 

approximately 110 vpd are using Smith Creek Road. 

Park County staff also estimated projected traffic volumes on Shields River Road based on projected land 

uses and operations in the study area. Staff estimate that traffic volumes on Shields River Road will increase 

by approximately 20 percent over the next 20 years. With this growth rate, the ADT is projected to be 294 

vpd and the peak season ADT is projected to be 408 vpd. 

2.4. SAFETY

MDT provided crash data on Shields River Road from January 1, 2009, to December 31, 2018. Records 

show seven crashes occurring within the study area during the crash analysis period. Of the recorded 

crashes, two resulted in serious injuries, one resulted in minor injuries, three resulted in property damage 

only, and in one crash the injuries were unknown. In addition to these seven crashes, three fatality markers 

were documented along the roadway during the field review. Further investigation showed that all three 

crashes occurred outside of the 10-year analysis period. A detailed crash report was available for the fatality 

near MP 6.0, which was a roll over crash that occurred in 2005. Information on the other two fatal crashes 

was not available. Figure 2.5 presents the location and severity of the crashes occurring during the 10-

year analysis period and the three additional fatal crashes noted during the field review. Note that this 

evaluation only includes those crashes that have been reported by a patrolling officer. Given the location 

and rural context of the roadway, there are likely additional crashes that have occurred but went unreported. 

2.4.1. Safety Trends, Contributing Factors, and Crash Clusters 

In general, crashes on Shields River Road are rare. During the 10-year crash analysis period, less than 1 

crash occurred per year, on average, with 2 occurring in 2017. All of the crashes occurred in the spring and 

summer months (March through August) and three occurred in July. The majority of the crashes (five) 

occurred at nighttime under unlit conditions. 

The main crash types were fixed object collisions (three) and rollover collisions (two). An additional fatal 

rollover crash occurred outside the 10-year analysis period. The other crash types were domestic animal 

and not fixed object or debris. An animal in the roadway was listed as a contributing circumstance in two of 

the crashes. Three of the crashes (two rollover and one fixed object) involved an impaired driver. 

All crashes involved a single vehicle and six of the seven involved only one occupant. Three of the crashes 

occurred under dry road conditions, three under wet, icy, or frost covered roads, and in one crash the road 

condition was unknown. Four of the crashes occurred when it was cloudy, two when it was clear, and one 

when it was raining. All of the crashes occurred within the first 7.5 miles of the study area. There is a cluster 

of rollover crashes near MP 6.0. This area has been discussed as a safety concern due to the steep side 

slopes, deteriorating roadway edges, and limited sight distance on the horizontal and vertical curves. 
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

 September 27, 2019 19

Figure 2.5: Crash Locations 

ELK CREEK M UDDYCREEK

POT ER CRE K

SHIELDS RIVER

DEEP CREEK

DAISY DEAN CREEK

COTTONWOOD

RESERVOIR HORSECREEK

SUNLI GHT C R EEK

SOUTH FORK SHIELDS

POTTER

CREEK RD

FLATHEAD CREEK RD

CRAZY BEAR GULCH

SHIELDS RIVER RD

BRIGHT LN

DAISY DEAN RD

ELK CREEK N

SHIELDS RIVER RD

ELK CREEK RD

HORSE CREEK RD

HILL RD

HORSE CREEK RD S

US HIGHWAY 89 N ANDERSON RD

MATHER LN

LODGEPOLE

PI N K E RTON RD

SMITH

CRE K RD

ELK CREEK RD S

PORCUPINE RD

SHY RD

ELK CREEK RD

JORDAN BENCH RD WOODS LN

COAL CAMP RD

OLD FLATHEAD

CREEK RD

Unknown2

Roll Over2Unknown2 Not Fixed

Object or

Debris

Fixed Object

Domestic

Animal

Fixed

Object

Roll Over

Roll

Over

Fixed Object

19

7

5

3

17

18

15

14

11

8

0

12

10

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Wilsall

89

86 38

25

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0 1 2 3 0.5 Miles

Map Legend

Crash Injury Severity

Crash Period: January 1, 2009

to December 31, 2018

1Only mile posts found during field review

are shown. 2

Identified during field review. Crash

occurred outside given data range. 

Unknown

Fatality

Serious Injury

Minor Injury

Property Damage Only

Mile Post1 Study Corridor
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

 September 27, 2019 20

2.5. OTHER VULNERABILITIES

There are locations along the corridor where natural land events, including landslides and erosion, have 

occurred. The following sections discuss these areas and how they may impact future road design, 

maintenance, and repair work on Shields River Road. Figure 2.6 presents these additional vulnerabilities 

along the study corridor as identified during the field review. 

Steep Slopes 

There are many locations along the corridor that have steep side 

slopes on one or both sides of the roadway. Areas with steep 

slopes may have an elevated risk of erosion. Slope failures, or 

landslides, typically occur where a slope is over-steep, where 

material is not compacted, or where cuts in natural soils 

encounter groundwater or zones of weak material. These areas 

of steep slopes are especially important to consider to help 

minimize the risk of slope failure and avoid the potential for 

expensive road repairs or road closures. Steep slopes can be 

stabilized by flattening the slope, adding drainage, or using 

retaining structures. There were 23 locations identified during the 

field review as having steep side slopes. Almost half of these 

steep slope locations (11) are between MP 3.6 and 8.1. 

Landslides 

Two landslide areas were documented in the study area during 

field review. The first is approximately located between MP 6.1 

and 6.5. This landslide area was informally rated as medium 

severity during the field review. The second landslide location is 

at approximately MP 7.5. This landslide was rated as low 

severity. Both landslides occurred on the right side of the 

roadway. 

A report prepared for MDT in 200217 indicates that there are other 

slide areas located along the Shields River approximately 

between MP 14.0 through the end of the study area. These slides 

are primarily associated with intrusive bodies and are located 

along stream cuts which indicates that undercutting played a role 

in the movement. The report also indicates that there is some 

faulting and folds located in these areas. 

Drainage/Erosion 

Improper drainage on a roadway can lead to serious erosion 

issues. When water falls on roads and is not removed promptly, 

the water seeps into lower layers of the pavement, weakens the 

soil which can compromise the soil stability and undermine the 

capacity of the pavement to carry traffic. There were seven 

locations along the corridor observed to have poor drainage or 

erosion issues during the field review. In some of these locations 

there were existing culverts built to divert water from the roadway 

while others had sections of culverts which had been detached 

allowing water to pool along the roadside. 

Areas with steep slopes may have an elevated 

risk of erosion, slope failures, or landslides. 

Steep slopes also pose a safety risk to drivers 

as they are difficult to recover from. 

Two landslide areas are documented along the 

corridor during field review. Slides caused by 

stream undercutting are also reportedly 

present in the study area. 

Improper drainage on the roadway can lead to 

serious erosion issues including deteriorated 

roadway edges. 
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Subgrade 

There are locations along the roadway where the subgrade was 

noted as being deficient during the field review. A weak or 

deteriorating subgrade is typically characterized by rutting, 

depressions, or upheaval in the pavement. This distress on the 

pavement can be caused by a variety of factors including frost 

heave, lack of compaction, or weak materials. The locations 

where deficient subgrade was noted occurred between MP 6.2 

and 13.5. 

A weak subgrade is characterized by rutting, 

depressions, or upheaval in pavement. 

There are several locations along the 

roadway where the subgrade was noted as 

being deficient. 
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Figure 2.6: Other Vulnerabilities 

ELK CREEK M UDDYCREEK

POT ER CRE K

SHIELDS RIVER

DEEP CREEK

DAISY DEAN CREEK

COTTONWOOD

RESERVOIR HORSECREEK

SUNLI GHT C R EEK

SOUTH FORK SHIELDS

POTTER

CREEK RD

FLATHEAD CREEK RD

CRAZY BEAR GULCH

SHIELDS

RIVER RD

BRIGHT LN

DAISY DEAN RD

ELK CREEK N

SHIELDS RIVER RD

ELK CREEK RD

HORSE CREEK RD

HILL RD

HORSE CREEK RD S

US HIGHWAY 89 N ANDERSON RD

MATHER LN

LODGEPOLE

PI N K ERTON RD

SMITH

CRE K RD

ELK CREEK RD S

PORCUPINE RD

SHY RD

ELK CREEK RD

JORDAN BENCH RD WOODS LN

COAL CAMP RD

OLD FLATHEAD

CREEK RD

19

7

5

3

17

18

15

14

11

8

0

12

10

4

Wilsall

89

86 38

25

37

22

36

23

24

26

27

28

7 BRIGHT LN SHIELDS RIVER RD

0 1 2 3 0.5 Miles

Map Legend

Severity2 Deficiency

1Only mile posts found during field

review are shown. 2As determined during field review.

Low

Medium

High

Unknown 

Mile Post1 Study Corridor

Landslide

Steep Slope

Subgrade

Drainage

Erosion
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3.0. ENVIRONMENTAL SETTING 

As with any roadway improvement project, the current and potential environmental conditions need to be 

considered. Most environmental concerns within the study area that may impact project development relate 

to the Shields River and the habitat it provides. Shields River and several other streams cross Shields River 

Road several times throughout the study area. Culverts and bridges have been placed to control these 

crossings however there are locations where erosion from the water has damaged the roadway causing 

the need for repairs. The river and surrounding wetlands provide a substantial habitat that supports diverse 

populations of fish and wildlife. Some of the species present in the study area are listed, or proposed for 

listing, under the Endangered Species Act (ESA). 

An Environmental Scan (Scan) (see Appendix D) has been prepared documenting the current 

environmental conditions. This section provides a summary of Scan which provides a planning‐level 

overview of resources and identifies potential constraints and opportunities based on readily available 

environmental information. Multiple environmental studies have been conducted in the study area over the 

course of several decades. Some of these have addressed proposed improvements to Shields River Road, 

while others have been concerned with larger-scale issues of land and resource management. Information 

from these past studies was reviewed and supplemented with publicly available data from federal, state, 

and local agencies. Improvement projects forwarded from this planning project which may impact the 

Shields River, the species supported by the watershed, the land surrounding the roadway, and the nearby 

populations will need to be considered. Project‐level environmental analysis would be required for any 

improvements forwarded from this study. Information contained in the Scan may be used to support future 

environmental 

3.1. PHYSICAL ENVIRONMENT

The following subsections present an overview of items related to the physical environment of the study 

area. 

3.1.1. Land Ownership and Land Use 

Almost all the land in the study area is privately held and are primarily used for agriculture (grazing and 

crop production) and forestry. There are also several residences accessed by Shields River Road along 

with two state-owned tracts within close proximity which are designated as State Trust Lands for agriculture 

and grazing. These lands are managed by the Montana Department of Natural Resources and 

Conservation. There are also conservation easements held by Montana Land Reliance, Montana 

Department of Transportation, and Gallatin Valley Land Trust in the study area. If any improvement options 

are forwarded from the planning study, additional research and coordination would be needed to ascertain 

the specific encumbrances that may be attached to each parcel of land. 

3.1.2. Soil Resources and Prime Farmland 

The Farmland Policy Protection Act (FPPA) (7 U.S.C. 4201 et. seq.) requires special consideration be given 

to soils considered as prime farmland, unique farmland, or farmland of statewide or local importance by the 

U.S. Department of Agriculture Natural Resources Conservation Service (NRCS). The FPPA is intended to 

minimize the impact Federal programs have on the unnecessary and irreversible conversion of farmland to 

nonagricultural uses. Based on the NRCS classifications, there are no soils classified as prime farmland, 

unique farmland, or farmland of local importance in the study area. Some mapped soils on the eastern side 

of the roadway between Pinkerton Road and Porcupine Road are classified as farmland of statewide 

importance. 
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Projects are subject to requirements in the FPPA if they may irreversibly convert farmland (directly or 

indirectly) to nonagricultural use. If any improvement options are forwarded from the planning study, 

coordination with the NRCS will be required to determine if the FPPA applies and necessary NRCS 

processing requirements. Projects planned and completed without the assistance of a Federal agency are 

not subject to the FPPA. 

3.1.3. Geologic Hazards 

The study area within the Shields River drainage basin which lies within the western part of the Crazy 

Mountains structural basin. The Crazy Mountains were formed by a massive domal uplift resulting in varied 

and complex bedrock outcrops. The Wilsall/Crazy Mountain area is in a moderate seismic risk zone. 

Earthquakes ranging from magnitude 1.5 up to 4.0 are not uncommon in the area. Geotechnical 

investigations will likely be required for reconstruction or significant improvements to Shields River Road to 

determine potential stability, erosion, and settlement concerns posed by surface geology and soil 

conditions. 

3.1.4. Surface Waters 

The study area lies entirely within the Shields River 

Watershed. The roadway also lies partially within the 

Lower Flathead Creek, Cottonwood Creek, Shields 

River-Antelope Creek, Shields River-Kavanaugh 

Creek, Porcupine Creek, Meadow Creek, and Shields 

River-Bennett Creek sub watersheds. 

Shields River Road generally parallels the Shields 

River throughout the entire study area. For 

approximately one mile, the roadway also parallels 

Flathead Creek. For an approximate 2.5-mile segment 

between Elk Creek W Road and Coal Camp Road, 

Shields River Road also parallels Porcupine Creek 

and one of its unnamed tributaries. The corridor 

crosses several streams and other named perennial, 

fish-bearing streams within the study area. Additional 

unnamed streams, wetlands, irrigation canals, ditches, 

and other waterbodies are also present. 

Road construction and reconstruction activities such as culvert installation or replacement, placement of 

fill, or bank stabilization have the potential for impacts to surface waters. Coordination with federal, state, 

and local agencies would be necessary to determine the appropriate permits based on the improvement 

options forwarded from this study. Impacts should be avoided and minimized to the maximum extent 

practicable. Impacts to streams and wetlands may trigger compensatory mitigation requirements. 

Water Quality 

The Shields River main stem is currently listed as “impaired” by the Montana Department of Environmental 

Quality (MDEQ) due to physical and ecology impacts derived mainly from sediment. The source of 

impairment is crop production, grazing in riparian zones, silviculture activities, and streambank 

modifications. The waterbody is classified as Category 4A by MDEQ, meaning all required total maximum 

daily loads are in place to correct identified impairments or threats. Shields River is also classified by MDEQ 

as Use Class B-1. The waterbody’s existing and anticipated beneficial use is primarily aquatic life 

(salmonid). Class B-1 waterbodies may also benefit drinking water, recreation, agriculture, or industry, 

although these uses have not yet been assessed. 

Shields River Road generally parallels the Shields River 

throughout the entire study area. The Shields River main 

stem is currently listed as “impaired” by MDEQ. 
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The Park Conservation District sponsors the Shields River Watershed Restoration Plan which was 

accepted by the MDEQ in June 2012 as a means of charting a path to improved water quality. The plan 

was developed by the Shields Valley Watershed Group which consists of landowners coordinating efforts 

to maintain productive and sustainable ranching lifestyles. Several restoration projects led by USFS and 

Montana Fish, Wildlife, and Parks (FWP) have also been completed to improve water quality and stream 

habitats within the Shields River watershed. 

In Montana, stormwater management is regulated by MDEQ. A Montana Pollutant Discharge Elimination 

System general permit is required for stormwater discharges from construction activities that result in the 

disturbance of equal to or greater than one acre of total land area. The applicability of this permit for Shields 

River Road would need to be reviewed for any project that may be brought forward from the planning study. 

Irrigation Features 

About 5,100 acres of lands surrounding the study area are irrigated with water originating in the upper 

Shields River basin. An additional 600 acres of land in the Porcupine Creek drainage is irrigated with water 

diverted from the South Fork of the Shields River. The two general types of irrigation in the Shields River 

Watershed are flood and sprinkler irrigation. The Big Canal is the largest irrigation canal in the study area 

at about 12 miles long and supplying about 2,200 acres of irrigated land. The Big Canal feeds several 

smaller ditches with the largest being the Myer’s Ditch. The Big Canal crosses Shields River Road at near 

MP 2.8 and Myer’s Ditch crosses at MP 3.2. Another, the Horse Camp Ditch, supplies water to about 760 

acres of irrigated lands and crosses Shields River Road at MP 12.0. Several other smaller ditches and 

canals exist throughout the study area and throughout the Shields River Watershed. Irrigation facilities that 

may be affected by improvement options advanced from this planning project should be coordinated with 

appropriate overseeing authorities and affected landowners to avoid or minimize impacts to agricultural 

operations and downstream water users. 

3.1.5. Groundwater 

Groundwater resources in northern Park County are under increasing pressure from land use change from 

irrigated cropland to residential. Much of the new development is dependent on individual household wells 

for potable water, and on septic systems for wastewater disposal. With increased use, there is a potential 

for groundwater resources to become overutilized in some locations. Based on available data, there are 

approximately 30 wells located within the study area. Well depths vary by individual location, but the 

majority of wells drilled in the study area have been drilled to depths of less than 100 feet. Static water 

levels vary considerably but range from 5 to 30 feet below the ground surface in most locations. Impacts to 

the groundwater supply should be considered in any improvement option that may be brought forward from 

the planning study. 

3.1.6. Floodplains and Floodways 

Several segments of Shields River Road cross or lie within Zone A (100-year floodplain) of the Shields 

River although the majority of the roadway lies outside the floodplain boundary (Zone X). Numerous major 

flood events have occurred within the Shields River Watershed in the past. High precipitation events and 

snowmelt from the Crazy Mountains are primary causes of flooding of the Shields River, however, the most 

significant flood events have occurred south of the study area. The Park County Flood Hazard Management 

Regulations regulate development activities in flood hazard areas. If any improvement options advanced 

from this study cross encroach on a regulated flood hazard area, it will be necessary to coordinate with and 

obtain a floodplain permit from the county floodplain administrator. 
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3.1.7. Wetlands and Waters of the U.S. 

Available data show primarily freshwater emergent wetlands and freshwater forested/shrub wetlands along 

the Shields River and other intermittent rivers, streams, and drainages. Wetland delineations would be 

required if improvement options are forwarded from the planning study that could potentially affect wetlands. 

Future projects in the study area would need to incorporate project design features to avoid and minimize 

adverse impacts on wetlands to the maximum extent practicable. Various state and federal water quality 

permits may be required to implement construction projects on the Shields River Road. 

3.1.8. Hazardous Substances 

The following summarizes potential hazardous sites within the study area: 

 Hazardous Waste Release Sites: Wilsall PCB Site, one mile north of Wilsall, is a smaller than 

one-acre area where a former resident dismantled electrical transformers and burned transformer 

oil, contaminating soils with polychlorinated biphenyls (PCBs), dioxins, and heavy metals. This site 

was identified as a hazardous waste release site in 1991 and was delisted in 1996 following cleanup 

activities. 

 Underground Storage Tanks: There are four active underground storage tanks at the Park 

Farmers Co-Op approximately one-half mile from Shields River Road. The tanks are located at the 

intersection of Elliot Street South (US Highway 89) and Shields Street West. All of the tanks are 

actively in use. 

 Petroleum Tank Releases: Mantz Texaco (Site 3403476) was identified as the site of a petroleum 

release in Wilsall, the incident was resolved in 2007. A second site, Park Farmers Coop (Site 

3406686), also located in Wilsall was identified as the site of a petroleum release in August 1993 

but it has not yet been resolved. A third site, Wilsall Consolidated School (Site 3405391), was 

resolved in 2000. Spear Lazy U Ranch L P (Site 3401300), is the fourth petroleum release site in 

the study area. It is located on Hill Road just north of Shields River Road and a release was 

identified in 2000 and resolved in 2003. 

At this time, none of the hazardous substance sites are expected to be “must avoid” locations or likely to 

affect project design. However, if a project were to overlap a hazardous substance site, a soil investigation 

would likely be needed to determine the extent of contamination and whether remediation may be 

necessary. If contaminated soils are present, a special provision regarding handling contaminated soils 

may be needed. 

3.1.9. Air Quality 

Park County is considered an attainment area for all pollutants and there are no nearby nonattainment 

areas. Since Park County is considered in attainment, for all pollutants, federally-funded transportation 

projects on Shields River Road by the FHWA would not be subject to conformity requirements.

3.1.10. Noise 

Residences in the study area comprise the only sensitive noise receptors that could be affected by roadway 

improvements on Shields River Road. Detailed noise analyses are often conducted when the potential for 

noise impacts exists due to substantial changes in roadway design or configuration. However, given the 

rural environment, low volumes of traffic, and dispersed nature of residences in the study area, noise 

impacts resulting from potential roadway improvements are unlikely. Construction activities associated with 

improvements to Shields River Road may result in localized and temporary noise impacts in the vicinity of 

residences. These impacts can be minimized by incorporating measures to control of noise sources during 

construction. 
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3.2. BIOLOGICAL RESOURCES

The following information applies to the biological environment within the study area and reflects a baseline 

natural resource condition. Depending on the level of detail available through the high-level baseline scan, 

some of the information is presented at the county level, some at the study area level, and some at the 

corridor level. 

3.2.1. Vegetation 

Native vegetation in the Shields River Valley is consistent with elevation-based gradients in mountain 

valleys of the northern Rocky Mountains. Some of the riparian vegetation at lower elevations in the Shields 

River watershed is woody species such as cottonwood, willow, and alder, but much of the woody vegetation 

in agricultural areas was historically removed and has been replaced by a mix of herbaceous vegetation 

and shrubs. As elevation increases, the vegetation turns to mesic and xeric shrub lands dominated by 

sagebrush, transitions to grasslands and, eventually, culminates in coniferous forests. The vegetation in 

the study area consists of agriculture/crops, grasslands, riparian, shrubs, and coniferous and deciduous 

forest. The forestland includes lodgepole pines, Douglas firs, and mixed mesic and subalpine forest 

species. 

Invasive weeds are a growing concern in the Shields River watershed. Priority species include Russian and 

spotted knapweed, leafy spurge, Dalmation toadflax, and whitetop. Russian and spotted knapweeds, 

Dalmatian toadflax, and leafy spurge have been identified by the Montana Noxious Weed Trust Fund as 

weeds that the Montana noxious weed survey and mapping system must monitor on a section basis. The 

Park County Weed Control District has been active in public education for noxious weeds. New 

developments are required to develop a weed management plan and landowners are encouraged to use 

biocontrol or large animal grazing. If improvement options are forwarded from this study, field surveys for 

noxious weeds should take place before any ground disturbance occurs. Proposed projects should 

incorporate applicable practices outlined by the Park County Weed Control District. Any projects forwarded 

from the feasibility study within the National Forest would need to comply with USFS management policies. 

Whitebark pines (Pinus albicaulis) are designated as a candidate species for listing under the ESA. 

Whitebark pines are typically found in cold, windy, high elevation or high latitude sites in western North 

America and as a result, many stands are geographically isolated. Whitebark pines are unlikely to occur 

along Shields River Road but may potential occur on high elevation forest lands in the area. 

3.2.2. Fish and Wildlife 

The Shields River Watershed provides breeding, resting, foraging, and migratory habitat for many species 

of fish and wildlife. The watershed has approximately 453 miles of habitat with 277 miles being inhabited 

by both native and non-native species and 176 miles having native fish species only. The study area 

supports eleven species among four families of fish. 

Yellowstone cutthroat trout is considered a sensitive species by the USFS and a Species of Concern by 

Montana. The Shields River watershed provides substantial habitat for Yellowstone cutthroat trout – the 

watershed contains 66 percent of the core and conservation populations. In the past twenty years, over 4 

million dollars has been spent on diversion dams and fish passage infrastructure within parts of the Shields 

River to maximize the watershed as a basin-level stronghold for Yellowstone cutthroat trout. 

The Shields River Valley supports diverse wildlife populations. The elk population is large with the majority 

occurring on the west side of the valley near the study area. The Shields River and its tributaries provide 

an attractive habitat for moose, and they can often be seen from Shields River Road during the winter. The 

Shields River Valley also supports an unusually high concentration of golden eagles; the largest antelope 
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population in Park County; and one of the largest mountain goat populations in the lower 48 states. The 

wetlands provide important staging, resting, and viewing areas for migratory waterfowl and shorebirds. A 

small population of remnant sage grouse, a species of concern throughout the western US, can also be 

found in the Shields River Valley. 

If any improvement projects are brought forward from this study, coordination should occur with fish and 

wildlife biologists from Montana FWP and the USFS to gain further insight into issues related to the 

management of these species, as well as measures for avoiding, minimizing, or mitigating adverse effects 

on species and habitat. 

3.2.3. Threatened and Endangered Species 

As noted earlier, whitebark pines, a candidate plant species for listing under the ESA, occurs within the 

Custer-Gallatin National Forest and is typically found in high elevation, upper montane habitat near the 

treeline. There are also three species of wildlife known or expected to use habitats in Park County which 

are listed or proposed for listing under the ESA. The grizzly bear and Canada lynx are threatened species 

present in the county while the wolverine is a proposed for listing species that may occur within mountainous 

and forested areas of Park County. All three of these species have been observed within the study area 

based on available information, although there are no designated critical habitats for these species within 

the study area. The wolverine is the only species that has been documented as having a sustained 

presence within the study area. Any improvements forwarded from the planning study would need to 

undergo review for compliance with the provisions of the ESA. The listing status of species and critical 

habitat can change over time; therefore, an up-to-date list of potentially affected species and critical habitats 

should be reviewed for each project. 

3.2.4. Other Species of Concern 

Species of Concern are native animals or plants that are at-risk due to declining population trends, threats 

to their habitats, restricted distribution, among other factors. The Environmental Scan lists three mammals, 

eight birds, one fish, and three plants considered to be Species of Concern with occurrences in this area of 

Montana and presents their federal and state statuses. A species occurrence is an area of land or water in 

which a species is, or was, present. If any projects are brought forward from this study, a thorough review 

of wildlife sightings databases should be conducted, and habitats near any proposed project sites should 

be evaluated to determine their suitability for any Species of Concern. Measures to avoid or minimize 

disturbance of these species or their habitat should be incorporated into project design and implementation. 

3.3. SOCIAL AND CULTURAL RESOURCES

The following subsections present an overview of the social and cultural environment within the study area. 

3.3.1. Demographic and Economic Conditions 

Implementing regulations for the National Environmental Policy Act require federal agencies to assess 

potential social and economic impacts resulting from proposed actions. FHWA guidelines recommend 

consideration of impacts to neighborhoods and community cohesion, social groups including minority 

populations, and local and/or regional economies, as well as growth and development that may be induced 

by transportation improvements. Demographic and economic information presented in this section is 

intended to assist in identifying populations that might be affected by improvements in the study area. 

According to the American Community Survey (ACS), Wilsall and Park County are much less diverse, 

racially and ethnically, than the state. Persons identifying as White make up 100 percent of the population 

in Wilsall and approximately 95 percent of the population in Park County. The percentage of the population 
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identifying as American Indian or Alaska Native is less in Park County (0.7 percent) as compared to 

Montana (4.4 percent). For all other races, Park County and Montana have comparable population 

distributions. 

Median household income in Wilsall is higher than both county and state median values. The median 

income in Wilsall is approximately 20 percent more than all households in Montana and 38 percent more 

than all households in Park County. The wealth of the Wilsall community is reflected in the two percent 

poverty rate cited in the ACS. The county and state have comparable poverty rates (13 and 14 percent, 

respectively) but the unemployment rate in Park County is approximately half of that of Montana (2.8 versus 

4.8 percent, respectively) over the 50-year period considered in the ACS. 

Park County’s economy is strong and growing. This is primarily attributed to the proximity of Yellowstone 

National Park which continues to attract high volumes of tourists. Park visitors from all over the world allow 

lodging, restaurant, retail, and entertainment industries in the county to thrive. However, in the northern part 

of the county, in the Shields River Valley, the economy has historically been driven by agriculture, forestry, 

fishing, and hunting. About 30 years ago, the Town of Wilsall was a small trade town on a Northern Pacific 

Railroad spur line. But the as the popularity of the Shields River Valley for anglers, hunters, and other 

recreationists has grown, Wilsall and surrounding communities have experienced notable increases in 

construction, retail, educational, and healthcare industries. Recreational facilities and opportunities 

available via Shields River Road, and its access to Custer-Gallatin National Forest, support the local 

businesses that sell fuel, sporting and camping equipment, groceries, meals, clothing, souvenirs, and other 

tourist associated commodities. Recreationists also contribute to the local economy by hiring one of the 

nearly two dozen local commercial outfitters or guides for fishing, hunting, horseback riding and/or pack trip 

activities permitted in this area. 

Title VI of the United States Civil Rights Act of 1964 and Executive Order 12898 require that projects 

receiving federal funds must not result in disproportionately high and adverse effects on minority or lowincome populations. For transportation projects, this means that minority or low‐income populations must 

not be disproportionately isolated, displaced, or otherwise subjected to adverse effects. If improvement 

options are forwarded from the planning study into project development, environmental justice would need 

to be further evaluated during the project development process. However, demographic data obtained for 

this study indicates minority and/or low-income populations are not present in the area. 

3.3.2. Recreational Resources 

In addition to providing access for an estimated 460 residences, Shields 

River Road also provides access to a multitude of developed and dispersed 

recreation opportunities in the Custer-Gallatin National Forest. Park County 

Public Works Department staff estimates that approximately 30,000 people 

visit and recreate in this area of Custer-Gallatin National Forest each year, 

although no formal counts have been conducted. 

Primary visitor destinations accessed by Shields River Road include Forest 

Service cabins, vacation rentals, designated and undesignated dispersed 

campsites, day-use sites, developed trailheads, trail systems, ATV routes, 

mountain lakes, and streams. Shields River Road, and land accessible by 

the roadway, is used for a variety of outdoor recreation experiences 

including bicycling, running, hiking, wildlife viewing, motorized activities, 

horseback riding, fishing, hunting, camping, and winter sports. Park County staff estimate that 

30,000 people visit and recreate 

in this area of Custer-Gallatin 

National Forest each year. 
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Access to the Crazy Mountains and historic mountain trails has long been the subject of contentious debate 

among private landowners, the Forest Service, and recreationists. Many of the public lands are accessed 

via trails that cross private land at the base of the mountains. Over the years, many of the access points 

have been closed through landowner disputes. This leaves Shields River Road as the most heavily utilized 

road by recreationalists on the west side of the Crazy Mountains. 

Recreation areas may be protected under Section 4(f) of the US Department of Transportation Act of 1966

if they are publicly owned, open to the public during normal hours of operation, and serve recreation 

activities as a major purpose as stated in adopted planning documents. There are no known designated 

day use sites, fishing accesses, trailheads, or camp sites within the study area that may be impacted by 

improvement options forwarded from the planning study. If improvement options are forwarded from the 

planning study, potential effects on recreational use should be investigated and appropriately considered 

in accordance with Section 4(f). 

Projects may also be subject to Section 6(f) of the Land and Water Conservation Fund Act which was 

enacted to preserve, develop, and ensure the quality and quantity of outdoor recreation resources. Section 

6(f) protection applies to all projects that affect recreational lands purchased or improved with Land and 

Water Conservation funds. Based on a project funding review, no areas qualify for protection under Section 

6(f) within the study area. 

3.3.3. Cultural and Historic Resources 

Federal agencies are required to consider the effects of their undertakings (including funding, licensing, or 

permitting the undertakings of other entities) on historic properties and must consult affected American 

Indian tribes. Available data identified the following tribes with potential interests in Park County, Montana: 

 Apache Tribe of Oklahoma 

 Crow Tribe of Montana 

 Fort Belknap Indian Community of the Fort Belknap Reservation of Montana 

 Shoshone-Bannock Tribes of the Fort Hall Reservation 

Implementing regulations also require agencies to seek ways of avoiding, minimizing, or mitigating any 

adverse effects on historic properties. There are no historic properties listed on the National Register of 

Historic Places within the study area. If any projects are brought forward from the planning study, a cultural 

resource survey for unrecorded historic and archaeological properties would need to be completed within 

the area of potential effect defined for each project. Direct and indirect impacts (such as visual, noise, and 

access impacts) to eligible or listed properties would need to be considered if improvements options are 

carried forward. 

3.3.4. Visual Resources 

The study area encompasses a wide variety of settings including the Shields River Road roadway corridor 

and county roads, rural development, national forestland, other public lands, and wetlands. Actions that 

may have visual impacts include projects on new location or that involve expansion, realignment or other 

changes that could alter the character of an existing landscape or move the roadway closer to residential 

areas, parks and recreation areas, historic or other culturally important resources. 
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4.0. AREAS OF CONCERN AND CONSIDERATION 

The following is a summary of observed trends and areas for further consideration. These areas were 

identified through review of as-built drawings, field review, past studies, public databases, and other 

resources. More discussion has been provided in the previous sections and is reiterated here as 

appropriate. 

4.1. TRANSPORTATION CONDITIONS

Section 2 identifies physical features, geometric conditions, traffic conditions, safety trends, and other 

vulnerabilities within the study area that may be affected by potential future improvements arising from this 

study. Project-level traffic, geometric, or safety analysis may be required for any improvements forwarded 

from this project. The following transportation system conditions were noted: 

Physical Features and Characteristics 

 All of the bridges along the corridor are rated “fair” condition or “good” condition. All bridges meet 

minimum design load rating standards. 

 Nearly 70 culverts were identified along the study corridor, 17 of those culverts were 30” or larger. 

Approximately 20 percent of the culverts were in poor condition. 

 The corridor does not meet the AASHTO minimum roadway surface width of 32 feet or the Park 

County minimum roadway width of 28 feet. The roadway width ranges from 22 to 29 feet, is paved 

from MP 0.0 to 15.8, and is gravel surfaced from MP 15.8 to 19.5. 

 The majority of the pavement in the corridor is in poor condition while the gravel is in good condition. 

Geometric Conditions 

 Based on as-built plans, about half of the horizontal curves on the first 14.35 miles of the study 

area meet or exceed a 60-mph design speed. Based on aerial photography, 13 curves on the last 

4.65 miles of Shields River Road meet minimum design standards for a 60-mph design speed. 

 No vertical curvature data are available; however, three vertical curves identified during the field 

review appear to have poor sight distances. 

 There are seven locations where sight distance is limited. Two locations are affected by roadside 

vegetation and the roadway geometrics limit the sight distance in five locations. 

Traffic Conditions 

 Existing traffic volumes range from approximately 300 vpd near US 89 to 50 vpd at the end of the 

study corridor. 

 Traffic volumes are projected to increase by approximately 20 percent of over the next 20 years. 

 Heavy trucks make up approximately 8 percent of the current vehicle mix. 

Safety 

 Records show seven crashes occurring within the study area between January 1, 2009, to 

December 31, 2018. Two crashes resulted in serious injuries and two resulted in non-serious 

injuries. Three fatalities occurred outside the 10-year analysis period. 

 Five crashes occurred at nighttime under unlit conditions. 

 The main observed crash types were fixed object collisions (three) and rollover collisions (two). An 

additional fatal rollover crash occurred outside the 10-year analysis period. 

 An animal in the roadway was listed as a contributing circumstance in two of the crashes while 

three of the crashes involved an impaired driver. 
Shields River Road Planning Project, MT Park 34(1)

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Other Vulnerabilities 

 Steep side slopes, landslides, drainage/erosion issues, and locations with subgrade issues are 

common concerns on Shields River Road. These events have caused road damage in the past. 

4.2. ENVIRONMENTAL SETTING

The Environmental Scan identifies physical, biological, social, and cultural resources within the study area 

that may be affected by potential future improvements arising from the Shields River Road Planning Project. 

Project‐level environmental analysis would be required for any improvements forwarded from this study. 

Information contained in the Environmental Scan may be used to support future environmental 

documentation for compliance with the National Environmental Protection Act. The following environmental 

concerns were noted: 

Physical Environment 

 Land surrounding the study area is primarily used for agriculture (grazing and crop production) and 

forestry, although there are also several residences accessed by Shields River Road. Conservation 

easements exist on a few parcels of land adjacent to Shields River Road. 

 The study area contains some soils classified as farmland of statewide importance by the NRCS. 

 The Wilsall/Crazy Mountains area is in a moderate seismic risk zone. Several earthquakes ranging 

from magnitude 1.5 up to 4.0 have occurred in the Crazy Mountains. 

 Shields River Road crosses several perennial, fish-bearing streams, additional unnamed streams, 

wetlands, irrigation canals and ditches throughout the study area. 

 The Shields River main stem is listed as “impaired” due to impacts derived from sediments. 

 Parts of Shields River Road lie within the 100-year floodplain of the Shields River. 

 There is one delisted hazardous waste release site, four active underground storage tanks, and 

four petroleum tank release sites (three are resolved) in the study area. 

 Residences in the study area comprise the only sensitive noise receptors that could be affected by 

roadway improvements on Shields River Road. 

Biological Resources 

 Invasive weeds are a growing concern in the Shields River watershed. 

 The Shields River Watershed provides breeding, resting, foraging, and migratory habitat for many 

species of fish and wildlife. The watershed provides substantial habitat for Yellowstone cutthroat 

trout - the watershed contains 66% of the core and conservation populations. 

 The Shields River Valley supports diverse wildlife populations including elk, moose, golden eagles, 

antelope, mountain goats, migratory waterfowl and shore birds, and sage grouse. 

 The grizzly bear, Canada lynx, wolverine, and whitebark pine tree are listed, or candidates to be 

listed, under the ESA. All three wildlife species have been observed in the study area and the 

whitebark pine may potentially occur on high elevation forest lands in the area. Several other 

mammal, bird, fish, and plant Species of Concern have also been observed in the study area. 

Social and Cultural Resources 

 Demographic data obtained for this study indicate minority and/or low-income populations are not 

present in the area. The economy has historically been driven by agriculture, forestry, fishing, and 

hunting and is supported currently by anglers, hunters, and other recreationists. 

 In addition to providing access for 460 residences, Shields River Road also provides access to over 

113,000 acres of Custer-Gallatin National Forest which offers a multitude of developed and 

dispersed recreation opportunities. 

 No resources qualifying for protection under Section 4(f) or Section 6(f) have been identified in the 

study area. 
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5.0. GOALS AND OBJECTIVES 

Goals and objectives were identified based on a comprehensive review of existing information and input 

from the project team, stakeholders, and the public. Goals and objectives are important in explaining why 

a potential improvement option may be necessary. The following goals and objectives reflect the existing 

social, environmental, and engineering conditions and recognize the local and regional use of Shields River 

Road and the adjoining transportation system. In addition to identified goals and objectives, all improvement 

options should be sensitive to the availability of funding for recurring maintenance obligations or for the 

construction of new improvements. 

Goal 1: Improve the safety and operation of the roadway facility. 

Available crash data and anecdotal information from partnering agencies and residents indicate a need to 

improve the safety of Shields River Road. During field review, several locations along the corridor with 

limited sight distance and substandard geometry were noted. There are also locations where fatal or serious 

injury crashes have been reported. This goal is intended to improve the safety of the roadway in order to 

meet the traveling needs of the public, including both visitors to Custer-Gallatin National Forest and local 

residents. Roadway upgrades and/or management strategies are necessary to achieve a higher level of 

safety and improved operations for Shields River Road. This can be achieved by improving the roadway to 

meet current geometric standards (to the extent practicable), providing adequate clear zones, improving 

drainage conditions, providing consistent road widths, and properly maintaining the roadway. 

Objectives: 

 Improve roadway elements to meet current design criteria to address identified safety concerns (to 

the extent practicable). 

 Manage travel speeds and provide adequate clear zones to improve operations and safety. 

 Provide consistent roadway widths and appropriate surfacing. 

Goal 2: Provide a roadway facility that accommodates future traffic growth, 

recreational activity, and reduces maintenance needs. 

Shields River Road provides access to over 113,000 acres of the Custer-Gallatin National Forest, multiple 

residences, agricultural lands, and several recreation areas. The corridor is used by local and regional traffic 

including passenger vehicles, commercial vehicles, agricultural equipment, pedestrians, bicyclists, ATVs, 

and others. The number of visitors to the National Forest is expected to continue to grow over time due to 

increased recreational interest and opportunities in the area. As a result, Shields River Road is expected 

to realize an increase in traffic, by both motorized and non-motorized transportation modes. As activity on 

the roadway increases, maintenance needs will also continue to increase. Proper and regular maintenance 

of Shields River Road will help ensure the corridor continues to adequately serve residents and visitors in 

the future. 

Objectives: 

 Accommodate existing and future travel demands. 

 Address non-motorized facilities consistent with local planning efforts. 

 Enhance connectivity for residents and regional users accessing recreational lands. 

 Reduce maintenance needs. 

Goal 3: Minimize adverse impacts to the environmental, cultural, scenic, and 

recreational characteristics of the study area. 

The Shields River Road serves residential, agricultural, and recreational lands. Over the past several years, 

this portion of Park County has become one of the most popular recreational destinations on the west side 
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

 September 27, 2019 34

of the Crazy Mountains. Because of its location along the Shields River and the unique scenic and 

recreational characteristics of the area, preservation of wildlife and aquatic connectivity and habitat are 

issues of high importance. All improvements should be reviewed for their potential impact to the 

environmental, scenic, cultural, and recreational aspects of the corridor. 

Objectives: 

 Minimize adverse impacts to riparian environments. 

 Minimize adverse impacts to the wildlife and aquatic organisms. 

 Provide reasonable access to recreational sites near the study area. 

 Avoid/minimize adverse impacts to historic, cultural, and archaeological resources. 
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6.0. IMPROVEMENT OPTIONS 

This section contains a list of potential improvements intended to address previously identified issues and 

areas of concern and satisfy corridor goals and objectives outlined in Section 5.0. The improvement options 

reflect input from stakeholders and the public, as well as information gathered from a thorough evaluation 

of the existing and projected conditions of the study corridor. The following steps were applied to develop 

improvement options: 

1. Identify roadway issues and areas of concern based on field review, engineering analysis of asbuilt drawings, crash data analysis, and consultation with stakeholders. 

2. Identify overall corridor goals and objectives. 

3. Analyze the information gathered to develop improvement options to address the roadway issues 

and areas of concern while ensuring consistency with the goals and objectives. 

Implementation of improvement options ultimately depends on the availability of funding, personnel 

resources, right-of-way needs, and other project delivery elements. Planning level cost estimates are listed 

in 2019 dollars for each improvement option. The costs include estimates for surfacing, striping, signing, 

culvert cleaning/replacement, guardrail installation, preliminary engineering, construction engineering, 

construction, and indirect costs. Appendix E contains planning level cost estimates for the options. 

Considerations related to project development and potential impacts are provided for each option. Potential 

barriers such as right-of-way, physical features, and environmental conditions may influence the project 

development process and could add additional time and cost. More detailed project-level analysis would 

be required for any improvements forwarded from this study. Information contained in this report may be 

used to support future project development and environmental documentation. 

6.1. DESIGN TYPICAL SECTIONS

The current roadway width varies throughout the corridor. In general, the roadway is currently 24 feet wide 

between MP 0.0 and 14.2; 26 feet wide between MP 14.2 and 15.7; 24 feet wide between MP 15.7 and 

16.8; and 20 feet wide between MP 16.8 and 19.5. Based on standards developed by AASHTO and Park 

County, roadway characteristics, and corridor function, the recommended roadway width ranges from 20 

to 30 feet (see Table 2.3). While it might be appropriate to maintain the current cross sections, it may also 

be beneficial to widen the roadway to a common typical section and to provide for widened shoulders. The 

roadway also currently lacks shoulder and centerline striping. There is a desire to include striping with future 

project(s) along the paved portion corridor to delineate travel lanes, shoulders, and passing zones. The 

width and surfacing of the gravel section (MP 15.7 to 19.5) is appropriate for existing and anticipated use. 

Three potential typical sections of varying widths were identified for the paved section of Shields River 

Road. These typical sections are based on existing standards and are aimed at addressing existing and 

projected demands, safety concerns, and project development constraints. The first option is to reconstruct 

Shields River Road with a consistent 24-foot roadway width. In most locations throughout the corridor, the 

roadway subgrade is already wide enough and would not need to be expanded to accommodate new 

surfacing. This typical section would include 12-foot travel lanes with no shoulders (Figure 6.1) and most 

closely matches what is in place today. The second option is to reconstruct the roadway to be 28-feet wide, 

consistent with Park County Transportation Standards. This would allow for 12-foot travel lanes and 2-foot 

shoulders (Figure 6.2). The third option is to reconstruct the roadway according to the AASHTO Greenbook 

standards for rural collector roadways. This standard calls for 11-foot travel lanes and 4-foot shoulders for 

a total surface width of 30 feet (Figure 6.3). 
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Figure 6.1: 24-foot Typical Section (Existing) 

Figure 6.2: 28-foot Typical Section (Park County Standards) 

Figure 6.3: 30-foot Typical Section (AASHTO Standards) 

Since Shields River Road provides access to recreational opportunities, residences, and agricultural lands, 

it is used by a variety of vehicles each with differing design needs. For example, wider travel lanes are 

recommended to accommodate the heavy vehicles and tractors in the area used for agricultural and 

commercial purposes. Widened shoulders are also desirable for non-motorized and recreational use along 

the corridor. A wider roadway may also improve sight distance, allowing more space for vehicles to 

maneuver curves, and provide for more recoverable area for traveling motorists. Conversely, increasing 

the roadway width may result in a more comfortable facility for drivers which can indirectly increase vehicle 

speeds. Widening the roadway more than the existing 24-foot width will also require additional subgrade 

and drainage work, resulting in increased construction impacts and higher costs. 
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There appears to be adequate right-of-way to widen Shields River Road to accommodate any of the three 

recommended typical sections. Since the traffic volumes on Shields River Road are relatively low, all three 

typical sections would also adequately accommodate existing and projected traffic volumes. The 

determination of which typical section is appropriate for the roadway will need to be evaluated in more detail 

during the project development process. With that in mind, the following sections provide a range of cost 

estimates depending on which typical section is used. 

6.2. ROADWAY RECONSTRUCTION/REHABILITATION

Reconstruction and rehabilitation of the roadway is needed due to deteriorated surfacing conditions and to 

accommodate existing and future needs. The following sections discuss design considerations for each 

segment, recommended improvement options based on identified typical sections, and estimated planninglevel costs. To evaluate potential project development options, the corridor was broken into multiple 

segments based on logical breaks and changes in roadway condition/context. Various considerations for 

each segment were identified including potential barriers and constraints such as physical features and 

environmental conditions which may influence the project development process and could add additional 

time and cost. 

Segment 1: US 89 to Pinkerton Road (MP 0.0 to 3.8) 

This segment starts on the northern edge of Wilsall and extends northeasterly through rural residential and 

agricultural lands. In this section, Shields River Road crosses two major streams, Flathead Creek and 

Shields River, via bridges which are both in fair condition. The pavement condition is generally poor or very 

poor based on a PASER evaluation. There are two locations where the pavement subgrade is visibly 

deteriorated, at MP 1.4 and MP 2.7, as evidenced by alligator cracking, potholes, and failing patch repairs. 

Steep side slopes are also present throughout this section which have the potential to cause erosion. There 

is one substandard horizontal curve at MP 3.2 where Jordan Beach Road joins Shields River Road. There 

have been three crashes along this segment over the past ten years, all of which were fixed object crashes 

of low severity between MP 0.0 and 1.3. 

Recommendations: 

 Reconstruct to typical section standard. 

Considerations: 

 Adjacent wetlands may be impacted by roadway improvements. 

 Shields River Road crosses or lies adjacent to delineated floodplains. 

 There are two bridges, both in fair condition and of adequate width. 

 The Big Canal crosses Shields River Road near MP 2.8 and the Myer’s Ditch crosses at MP 3.2. 

 There are five culverts in need of additional evaluation. 

 There is one concrete stock pass in this section at MP 3.2. 

Estimated Cost: 

 Typical Section 1 (24-feet): $2,300,000 

 Typical Section 2 (28-feet): $3,500,000 

 Typical Section 3 (30 feet): $3,900,000 

Segment 2: Pinkerton Road to Porcupine Road (MP 3.8 to 8.4) 

Shields River Road parallels the Shields River and Porcupine Creek through the majority of this segment. 

The roadway also crosses Porcupine Creek and one of its tributaries at MP 7.6 and 7.9, respectively. The 

pavement condition of this segment was evaluated as very poor to poor. The surfacing between MP 5.5 
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

 September 27, 2019 38

and 8.0 is especially poor with evidence of sloughing, cracking, and erosion. The proximity of the river 

throughout this section, combined with steep side slopes and landslide areas, presents special geotechnical 

concerns. Several active landslides were documented during the field review on the east side of Shields 

River Road between MP 6.1 and 7.5. The geometric review showed seven substandard horizontal curves 

and one substandard vertical curve. At one location, MP 8.0, a combination horizontal/vertical curve was 

also noted as having sight distance issues. There have been five crashes along this segment over the past 

ten years. There is a cluster of three rollover crashes at a tight s-curve near MP 6.0. Two of the three fatality 

markers noted in the study area are present in this section. 

Recommendations: 

 Reconstruct to typical section standard. 

 Flatten side slopes and install guardrail on s-curve near MP 

6.0. 

Considerations: 

 The roadway surfacing is failing with evidence of 

geotechnical and slope stability issues. 

 Shields River Road crosses or lies adjacent to delineated 

floodplains. 

 There are four culverts noted as needing additional 

environmental evaluation. 

 There are concrete stock passes at MP 4.2 and 6.0. 

Estimated Cost: 

 Typical Section 1 (24-feet): $3,300,000 

 Typical Section 2 (28-feet): $5,100,000 

 Typical Section 3 (30 feet): $5,600,000 

Segment 3: Porcupine Road to Hill Road (MP 8.4 to 14.2) 

Shields River Road generally parallels the Shields River throughout this section. The roadway crosses the 

river at MP 14.1 via a bridge that is in good condition. There are seven major culverts in this section, 

including several associated with the Horse Camp Ditch. Several of the culverts in this section are in poor 

condition with detached culvert sections at MP 14.0 and poor roadside drainage. There is evidence of water 

pooling at MP 9.7, 12.2, and 12.3. The pavement ranges from failing to fair based on the PASER evaluation. 

Between MP 12.0 and 13.5 the surfacing is especially poor and shows evidence of severe degradation 

including alligator cracking and failing patch repairs. The roadway is relatively flat through this section with 

steep side slopes in a few areas. There are six substandard horizontal curves at two locations, MP 11.3 

and 13.8. These areas are noted as having sight distance issues due to trees and other vegetation in the 

clear zone. There is a fatality marker in this this section at MP 12.9 which appears to be at one of the 

substandard horizontal curves. 

Recommendations: 

 Reconstruct to typical section standard. 

Considerations: 

 Adjacent wetlands may be impacted by development. 

 Shields River Road crosses or lies adjacent to delineated floodplains. 

 There are 12 culverts noted as needing additional environmental evaluation. 

There are safety concerns at MP 6.0 due 

to steep side slopes, deteriorating roadway 

edges, and limited sight distance. 
Shields River Road Planning Project, MT Park 34(1)

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Estimated Cost: 

 Typical Section 1 (24-feet): $3,500,000 

 Typical Section 2 (28-feet): $5,300,000 

 Typical Section 3 (30 feet): $5,900,000 

Segment 4: Hill Road to Smith Creek Road (MP 14.2 to 15.7) 

This segment of Shields River Road was paved in 2010 as part of an ARRA project. There are no major 

bridges or culverts in this section. The intersection where Hill Road, Hamilton Road, and Shields River 

Road meet (MP 14.2) is a sharp 90-degree curve. The intersection has stop control along Hill Road but is 

missing signage along Hamilton Road. Additional signing warning of the sharp curve is also missing or has 

fallen over. 

The community has expressed interest in building a parking lot for winter use at the intersection of Shields 

River Road and Smith Creek Road (MP 15.7). The parking lot is desired to be large enough for about 45 

cars and 15-20 trucks plus trailers and plowed, upon request, during the mid-December to mid-April season. 

The primary purpose of this parking area would be to facilitate snowmobile and other winter recreational 

access. 

The existing surfacing is currently in good to very good condition. A chip seal is needed to help preserve 

the condition of the surfacing, and to extend the overall pavement life. At some point in the future, 

resurfacing will also likely be needed. 

Recommendations: 

 Pavement preservation and general maintenance. 

 Enhance signage at MP 14.2 (intersection of Shields 

River Road/Hill Road/Hamilton Road) to warn drivers of 

the sharp curve. 

 Coordinate with USFS and private residences to 

construct parking lot at the Shields River Road/Smith 

Creek Road intersection. The parking lot is estimated to 

cost approximately $25,000 not including right-of-way. 

(Note: this cost is not included in cost estimate) 

Considerations: 

 Adjacent wetlands may be impacted by development. 

 There is a conservation easement held by Gallatin Valley Land Trust on both sides of the roadway 

between MP 14.2 and 14.5. 

 Additional right-of-way from private land owners would be required to construct the desired parking 

area at the intersection with Smith Creek Road. 

Estimated Cost: 

 $70,000 (chip seal) 

 $640,000 (resurfacing) 

Segment 5: Smith Creek Road to End Project (MP 15.7 to 19.5) 

This portion of Shields River Road has gravel surfacing. In 2010, the surfacing was improved, and the 

roadway widened to 24 feet from MP 15.7 to 16.8 and to 20 feet from MP 16.8 to 19.5 as part of an ARRA 

project. Included in the project was the replacement of an existing single-lane bridge over the Shields River 

(MP 16.8) with a new two-lane bridge along with asphalt paving for a short section on the bridge 

approaches. Other drainage crossings were also improved with the project. 

Most of the existing signage at the 

intersection of Hill Road/Hamilton 

Road/Shields River Road has fallen over or is 

missing. 
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

 September 27, 2019 40

Shields River Road crosses the Shields River, South Fork Shields River, and Mill Creek through this section. 

There are 3 major culverts and 15 total culverts, all of which are in good condition. There are 13 substandard 

horizontal curves and 2 substandard vertical curves in this section. Two vertical curves (MP 17.5 and 18.1) 

and two horizontal curves (MP 19.3 and 19.4) were documented as having sight distance/clear zone issues 

during the field review. At MP 17.4, 18.3, and 19.2, areas of steep side slopes exist on the north side of the 

road. 

The gravel surfacing is generally rated as good based on the PASER assessment. Annual maintenance is 

needed to maintain the surfacing and to reduce the presence of rutting and washboards. Ensuring proper 

roadway drainage will also help extend the life of the surface. At some point in the future, resurfacing will 

likely be needed. 

Recommendations: 

 Roadway preservation and general maintenance. 

Considerations: 

 Shields River Road crosses or lies adjacent to delineated 

floodplains. 

 There are five culverts noted as needing additional 

environmental evaluation should improvements occur. 

Estimated Cost: 

 Annual maintenance 

 $790,000 (resurface) 

6.3. COMBINED RECONSTRUCTION

The previous section provided options for improving the roadway in segments. A segmented approach was 

evaluated due to the anticipated difficulty in securing funding for improving the length of the corridor. A 

combined reconstruction approach is discussed in this section should it be desirable to improve the corridor 

with a single project. This combined approach includes all of the improvements identified for Segments 1, 

2, and 3 of the Shields River Road. Although more expensive, this approach addresses the most critical 

areas of concern in a single project. Included in this option is reconstruction of the pavement surfacing from 

MP 0.0 to 14.2. Additional enhancements to improve the safety of roadway users, including guardrail and 

signage, are also recommended. 

Recommendations: 

 Reconstruct to typical section standard from MP 0.0 to 14.2. 

 Install guardrail on s-curve at approximate MP 6.0. 

 Enhance signage at MP 14.2 (intersection of Shields River Road/Hill Road/Hamilton Road) to warn 

drivers of sharp curve. 

Considerations: 

 The roadway surfacing is failing with evidence of geotechnical and slope stability issues at spot 

locations, particularly between MP 6.1 and 7.5. 

 Adjacent wetlands may be impacted by roadway reconstruction. 

 Shields River Road crosses or lies adjacent to delineated floodplains. 

 There are 27 culverts noted as needing additional environmental evaluation. 

The gravel surfacing is in good condition. 

General preservation and maintenance 

should be completed annually to extend 

the life of the surface. 
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

 September 27, 2019 41

Estimated Cost: 

 Typical Section 1 (24-feet): $9,100,000 

 Typical Section 2 (28-feet): $13,900,000 

 Typical Section 3 (30 feet): $15,400,000 

6.4. SUMMARY OF OPTIONS AND ESTIMATED COSTS

The improvement options described in the previous sections are intended to offer a range of potential 

mitigation strategies for corridor issues and areas of concern. Five improvement options were proposed for 

logical segments of the roadway. An option is also presented which includes full reconstruction of the 

section of the corridor with poor asphalt pavement conditions. A summary of the improvement options is 

provided in Table 6.1 and shown graphically in Figure 6.4. 

Table 6.1: Improvement Options Summary 

Segment Recommendation Estimated Cost 

Segment 1: US 89 to 

Pinkerton Road 

(MP 0.0 to 3.8) 

 Reconstruct to typical section standard. 

 24-feet: $2.3M 

 28-feet: $3.5M 

 30-feet: $3.9M 

Segment 2: Pinkerton Road 

to Porcupine Road 

(MP 3.8 to 8.4) 

 Reconstruct to typical section standard. 

 Install guardrail on s-curve at approximate MP 6.0. 

 24-feet: $3.3M 

 28-feet: $5.1M 

 30-feet: $5.6M 

Segment 3: Porcupine Road 

to Hill Road 

(MP 8.4 to 14.2) 

 Reconstruct to typical section standard. 

 24-feet: $3.5M 

 28-feet: $5.3M 

 30-feet: $5.9M 

Segment 4: Hill Road to 

Smith Creek Road 

(MP 14.2 to 15.7) 

 Pavement preservation and general maintenance. 

 Enhance signage at MP 14.2 (intersection of Shields 

River Road/Hill Road/Hamilton Road) to warn drivers 

of sharp curve. 

 $70k (chip seal) 

 $640k (resurfacing) 

Segment 5: Smith Creek 

Road to End Project 

(MP 15.7 to 19.5) 

 Preservation and general maintenance. 

 Annual maintenance 

 $790k (resurfacing) 

Combined Reconstruction 

(MP 0.0 to 14.2)

 Reconstruct to typical section standard. 

 Install guardrail on s-curve at approximate MP 6.0. 

 Enhance signage at MP 14.2 (intersection of Shields 

River Road/Hill Road/Hamilton Road) to warn 

drivers of sharp curve. 

 24-feet: $9.1M 

 28-feet: $13.9M 

 30-feet: $15.4M 
Shields River Road Planning Project, MT Park 34(1)

 Preliminary Engineering Report 

 September 27, 2019 42

Figure 6.4: Improvement Options 

ELK CREEK M UDDYCREEK

POT ER CRE

K

SHIELDS RIVER

DEEP CREEK

DAISY DEAN CREEK

COTTONWOOD

RESERVOIR HORSECREEK

SUNLIGHT CR EEK

SOUTH FORK SHIELDS

POTTER

CREEK RD

FLATHEAD CREEK RD

CRAZY BEAR GULCH

SHIELDS RIVER RD

BRIGHT LN

DAISY DEAN RD

ELK CREEK N

SHIELDS RIVER RD

ELK CREEK RD

HORSE CREEK RD

HILL RD

HORSE CREEK RD S

US HIGHWAY 89

N ANDERSON RD

MATHER LN

LODGEPOLE

PI N K ERTON RD

SMITH

CRE K RD

ELK CREEK RD S

PORCUPINE RD

SHY RD

ELK CRE K RD

JORDAN BENCH RD WOODS LN

COAL CAMP RD

OLD FLATHEAD

CREEK RD

Segment: 4 MP 14.2 to 15.7 Segment: 3 MP 8.4 to 14.2

Segment: 5 MP 15.7 to 19.5

Segment: 1 MP 0.0 to 3.8

Segment: 2 MP 3.8 to 8.4

Enhance Signage MP 14.2

Install Gaurdrail on S-Curve MP 6.0

19

7

5

3

17

18

15

14

11

8

0

12

10

4

Wilsall

89

86 38

25

37

22

36

23

24

26

27

28

The Combined Reconstruction improvement option

includes Segments 1 - 3 and the spot improvements 

at MP 6.0 and MP 14.2.

1Only mile posts found during field review

are shown. 0 1 2 3 0.5 Miles Map Legend

Spot Improvement

Segment 5

Segment 4

Segment 3

Segment 2

Segment 1

Mile Post1
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7.0. PUBLIC MEETING SUMMARY 

Education and outreach are essential elements in successfully informing individuals about the planning 

process and soliciting feedback on the study outcomes. A public meeting was held at the Shields Valley 

Senior Citizens Center in Wilsall, Montana on Tuesday August 13, 2019 from 4:30 to 6:30 PM to give 

members of the public an opportunity to speak with project staff and have their questions answered about 

the planning study. The Public Meeting Summary (Appendix G) reviews the meeting details and 

summarizes the public comments received. To effectively notify interested parties about the opportunity to 

attend the public meeting and offer comments to the planning team, several notification methods were 

employed including postcard meeting invitations, email invitations, distribution of flyers, social media posts, 

and advertisements on the project website. 

The public meeting was formatted as an open house with no formal presentation. This format allowed each 

attendee to speak directly with project staff and/or representatives from FHWA and Park County. Display 

boards were used to summarize key points from this Preliminary Engineering Report and facilitate 

discussion. The public also had the opportunity to review and comment on the recommended improvement 

options. 

A total of 36 community members signed in at the public meeting and two written comments were received 

at the meeting. Additional comments were received after the meeting during the public review period of this 

Preliminary Engineering Report (Appendix H). In general, questions and comments centered on current 

roadway conditions, potential benefits and drawbacks of improvement options, and other project concerns 

that should be considered. The following highlights the verbal comments received: 

 Timeline: Some attendees were concerned about the deterioration of the roadway over the next 

several years before construction can be completed and the costs of maintenance within that same 

time. Project staff explained that future improvements would be implemented by Park County and 

the availability of funding is the primary factor on when a project may be constructed. 

 Heavy Vehicle Traffic: Some of the participants were concerned with the impact that heavy 

vehicles (logging and agricultural equipment) have on Shields River Road. These vehicles were 

cited as a cause of some of the poor pavement conditions including pot holing and rutting. 

 Maintenance: Many of the participants expressed frustration regarding the current condition of 

Shields River Road. Although maintenance work occurs annually, the repairs often fail after the 

following winter and freeze/thaw period and are not a solution to the main problems. 

 Safety: Safety was noted as a concern by many meeting attendees. High speeds combined with 

tight curves, steep side slopes, and poor pavement were cited as common causes of crashes or 

near misses on Shields River Road. In particular, the area between MP 6.0 and 7.2 is of concern 

from a safety standpoint due to the narrow roadway, poor geometrics, and steep slopes. 

In general, most participants agreed that repaving Shields River Road from MP 0.0 to 14.2 is needed. Most 

participants also felt that the newly paved portion past MP 14.2 and the gravel section were fine as is and 

only need general annual maintenance. Regarding the options for repaving the corridor, there were mixed 

opinions. Some felt that the 24-foot typical section was fine and should be kept to expedite project 

development due to the lower costs. Participants favoring this option noted the low traffic volumes and 

immediate need for resurfacing as reasons for support. Others felt a wider section with shoulders, such as 

Option 2 with a 28-foot typical section, would be better. A wider roadway was said to be needed to 

accommodate the large agriculture vehicles, improve safety, and provide room for snow storage. Some 

participants felt it would be short sighted to not expand the roadway to meet future demands. Most 

participants agreed that the 30-foot typical section is not necessary (Option 3). Regardless of which option 

is selected, most participants expressed a desire for centerline and shoulder striping. 
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8.0. CONCLUSION AND NEXT STEPS 

This study evaluated the Shields River Road corridor to gain a better understanding of corridor goals, 

objectives, constraints, and opportunities. A thorough analysis of applicable data from Park County, FHWA, 

USFS, MDT and other resources was conducted to identify an initial set of improvements that would 

address the operational characteristics, safety, and physical condition concerns of the existing facility. This 

evaluation led to a set of improvement options to be considered by appropriate project sponsors moving 

forward. 

The pavement on the first 14.2 miles of Shields River Road is old and in poor condition. In order to preserve 

access to the residential, agricultural, and recreational lands, improve safety, and accommodate future 

travel demands, reconstruction of the roadway is necessary. From an implementation standpoint, it may be 

desirable to improve the roadway incrementally. With this in mind, three reconstruction project segments 

were identified: Segment 1: MP 0.0 to 3.8; Segment 2: MP 3.8 to 8.4; Segment 3: MP 8.4 to 14.2. If desired, 

and if funding can be secured, these segments can also be combined into a single project to improve the 

14.2-mile section. 

The remaining 5.3 miles of the study corridor were recently improved by the Forest Service through an 

ARRA project. This section of the corridor is still in good condition and does not need full reconstruction. It 

is recommended that a chip seal be completed along the pavement section (MP 14.2 to 15.7) to preserve 

and extend the surfacing life. The gravel section (MP 15.7 to 19.5) should receive annual maintenance to 

ensure proper roadway drainage to reduce rutting, potholes, and washboards. Cost estimates are also 

provided for future resurfacing of these segments. 

The ability to develop a project is dependent on the availability of existing and future funding. At the current 

time, funding has not been identified to proceed with a project. Should Park County elect to proceed with a 

project, the following steps are needed: 

 Identify the option(s) that best meets the safety, environmental, and social needs in the area 

identified in the study; 

 Identify and secure a funding source or sources; and 

 Follow appropriate guidelines for project nomination and development, including a public 

involvement process and environmental documentation that describes potential impacts and 

mitigation measures from the proposed action. 

Any future project should be consistent with the needs and objectives contained in this study. Should this 

study lead to a project (or projects), compliance with appropriate funding and environmental regulations will 

be required. The information presented in this report can serve as a baseline for future project development 

and to apply for funding support. 
Shields River Road Planning Project, MT Park 34(1)

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 September 27, 2019 45

REFERENCES 

1

 Park County, Capital Improvements Plan 2016-2020, 

http://www.parkcounty.org/uploads/files/departments/30/Park-County-2016-2020-Capital-ImprovementsPlan.pdf

2

 US Forest Service, Gallatin Forest Plan, 1987, Amended December 1, 2015, 

https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fseprd487022.pdf 

3

 Forest Service, USDA, The Gallatin National Forest Land and Resource Management Plan, Final 

Environmental Impact Statement, 1987, 

https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fseprd497084.pdf

4

 United States Forest Service, Shields River Road Improvement Decision Notice and Environmental 

Assessment, 2004. Unknown reference. 

5

 Forest Service, Gallatin National Forest Travel Management Plan, Record of Decision, October 30, 

2006. 

6

 Park County, Park County Active Transportation Plan 2016-2020, February 25, 2016, 

http://www.parkcounty.org/uploads/files/pages/43/Final-Park-County-Active-Transportation-Plan.pdf

7

 Park County, Nittany Grant Works, Land Solutions, LLC, Park County Growth Policy, May 1, 2017, 

http://www.parkcounty.org/uploads/files/pages/36/Growth-Policy-with-Appendices-attached.pdf

8

 FHWA. December 1995. Report number PD-96-001. “Recording and Coding Guide for Structure 

Inventory and Appraisal of the Nation’s Bridges. 

9

 23 CFR 490.409 – Calculation of National Performance Management Measures for Assessing Bridge 

Condition. 

10 Montana Department of Transportation, Bridge Design Standards, 

https://www.mdt.mt.gov/other/webdata/external/bridge/design-stds-manual/design_stds_manual.pdf

11 Park County, Transportation Standards, Adopted October 28, 2014, 

http://www.parkcounty.org/pdfs/RdD/2014-10-31%20TS%20Standards_Sept2015.pdf

12 American Association of State Highway and Transportation Officials. 2002.Standard Specifications for 

Highway Bridges. 17th Edition. Washington, D.C. 

13 United States Department of Agriculture Forest Service, Motor Vehicle Use Map Custer Gallatin 

National Forest, 2018, https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fseprd582785.pdf

14 Park County, Park County Road Maintenance, 

https://parkcounty.maps.arcgis.com/apps/webappviewer/index.html?id=876e7852b92f48ceb2cc0671a69e

92b9

15 American Association of State Highway and Transportation Officials, A Policy on Geometric Design of 

Highways and Streets, 7th Edition, 2018, Washington, D.C. 

16 American Association of State Highway and Transportation Officials. 2001. Guidelines for Geometric 

Design of Very Low Volume Local Roads (ADT≤400). Washington, D.C. 

 
Shields River Road Planning Project, MT Park 34(1)

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 September 27, 2019 46

 

17 Montana Bureau of Mines and Geology, Compilation of Landslide Location Maps and Index for 

Identification of Slide-Prone Areas: A Pilot Study for the Butte District, December 2002, 

https://www.mdt.mt.gov/other/webdata/external/research/docs/research_proj/landslide/final_report.pdf