US-191 / MT-64 Wildlife & Transportation Assessment

Map 191 Assessment study area - Copyright: Center for Large Landscape Conservation

Exploring options to improve traveler safety and maintain wildlife movement in a gateway to Yellowstone

Yellowstone National Park’s 2.2 million acres provide critical habitat for the largest concentration of wildlife in the lower 48 states. But this habitat doesn’t stop at the park borders.

Herds of elk, deer and pronghorn move in and out of Yellowstone to access seasonal ranges, and predators like wolves and grizzly bears travel great distances. These species, along with bighorn sheep, wolverines, and others, move throughout the Greater Yellowstone Ecosystem—a richly biodiverse area composed of a patchwork of public and private lands.

However, directly northwest of the park, in Montana, this region is increasingly affected by growing traffic on roads and new subdivisions. As the area’s economy has expanded, so has the number of wildlife-vehicle collisions.

The US-191/MT-64 Wildlife & Transportation Assessment addresses this challenge by improving knowledge of wildlife movement and road safety along roads that connect Yellowstone National Park to the growing Montana population centers of Bozeman and Big Sky.

Goals of the Assessment: 

  • Identify areas with high levels of wildlife-vehicle collisions and those that are important to maintain wildlife movement
  • Inform and support communities and agencies in decision-making
  • Recommend measures to improve road safety as well as habitat connectivity for both land and aquatic species 

The Assessment report and Key Findings describe 11 priority sites and recommendations to reduce wildlife-vehicle collisions and reconnect habitat along this gateway to Yellowstone. 

Download Key Findings


Full Report: View the full report on the US-191/MT-64 Wildlife & Transportation Assessment (164 pages).

Data Portal & ROaDS tool: An accompanying data website allows citizen scientists to record sightings of live and roadkilled animals via a mobile app and describe important wildlife movement areas along the US-191 and Lone Mountain Trail road corridors. 

Flyer: Read a 2-page description of the Assessment. 

Community Information Sessions:

In October and November 2023, the Center for Large Landscape Conservation hosted a series of Community Information Sessions in Big Sky, Gallatin Gateway, and West Yellowstone, Montana. At each event, Center staff members presented key findings of the Assessment (see video below from the Big Sky session), including priority sites for mitigation, and responded to questions from community members. Representatives of the Montana Department of Transportation and Gallatin County also participated. Center staff are continuing to work with agency representatives and community members to further develop potential wildlife accommodation measures in 2024. 

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The Assessment is a joint project of the Center for Large Landscape Conservation and Montana State University’s Western Transportation Institute.

Western Transportation Institute

The US-191/MT-64 Wildlife & Transportation Assessment was made possible by the generosity of the following funders:

Big Sky Resort Area District
Moonlight Community Foundation
The Volgenau Foundation
Yellowstone Club Community Foundation

The above funders, along with:

Turner Foundation
Weeden Foundation
Cinnabar Foundation

are supporting continued work to share the findings of the Assessment and to lay the groundwork for potential implementation of recommendations.

Questions about the assessment? Please contact us at

Banner Photo: The Gallatin River and US-191 near Big Sky, Montana – Adobe Stock; Elk photo: NPS/Jacob W. Frank

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