Big Sky Resort Area District allocates $179k to study feasibility of wildlife crossing site
CENTER FOR LARGE LANDSCAPE CONSERVATION
This article is the last in a three-part series on wildlife-vehicle conflict. Catch up with part one and part two.
The Gallatin Valley has it all. Its natural beauty, access to recreation and quality of life all make it a highly desirable place to live and to visit. But can a place be too popular? U.S. Highway 191 through Gallatin Gateway is among the busiest two-lane highways in the state, with around 16,000 vehicles traveling on it each day. The growth of Gallatin County’s population and robust tourism in this gateway to Yellowstone National Park may be great news for the region’s economy but is not-so-great news for wildlife.
Adjacent to much of U.S. 191, the Gallatin River corridor serves as a migration route for deer and elk, and connects habitat for species such as wolverines, lynx, grizzly bears, mountain lions and wolves. Yet, the presence of U.S. 191 along the corridor means a high-volume road bisects national forest, wilderness areas and even a corner of Yellowstone National Park. The result is wildlife-vehicle collisions, and the less obvious “barrier effect” of heavy traffic on the daily and seasonal movement of a host of species.
Data from accident reports and animal carcass counts suggest a recent surge in collision numbers, which are a problem for human safety, in addition to wildlife. Unfortunately, impacts are likely even broader than available data indicate.
“What researchers see from systematic roadkill surveys in other locations is that road-killed animal numbers are often much higher than the crash and carcass data. This is especially true for smaller or rarer species, and for large animals that get hit, but don’t die on the road,” said Liz Fairbank, a road ecologist with the Bozeman-based, nonprofit Center for Large Landscape Conservation.
In 2021, the organization initiated a citizen science effort, involving local volunteers in mapping observations of live and road-killed wildlife on the highway. Fairbank says the data they collected complements the state’s carcass and collision data and enriches understanding of wildlife movement.
In 2023, CLLC and Montana State University’s Western Transportation Institute published the results of a multi-year U.S. 191/MT-64 Wildlife and Transportation Assessment. The Assessment combined local and expert knowledge, public data, citizen science and engineering expertise to identify important areas where wildlife accommodation measures—such as culverts, bridges, underpasses, overpasses and animal detection systems, together with fencing—can improve the safety of travelers and wildlife.
The assessment found 11 priority sites and developed recommendations to reduce wildlife-vehicle collisions and reconnect habitat along the 80-mile stretch of U.S. 191 between Four Corners and West Yellowstone, along with Montana Highway 64 (Lone Mountain Trail). The study analyzed 25 data sets from public sources and citizen science, including GPS-collared animals, aerial surveys, wildlife-vehicle collisions, wildlife carcasses, and habitat characteristics. Each 0.1-mile road segment was investigated, and priority areas were examined by a team of independent researchers and county, state and federal agency representatives.
The first and second highest-ranked priority sites are the Gallatin Gateway to Spanish Creek and the north of Big Sky entrance areas (the latter tied for second with a site surrounding Porcupine Creek). Now that priority sites have been identified, the next step to pursue measures within these or other areas is an engineering feasibility study of the exact location, design, constructability and cost of potential wildlife accommodations.
On June 6, the Big Sky Resort Area District allocated $179,000 to study the north of Big Sky entrance site. An engineering firm will examine wildlife overpasses, bridge retrofits and associated accommodations, including fencing to funnel wildlife to suitable structures, at this area and the “mouth of the canyon” within the Gallatin Gateway to Spanish Creek priority area.
Whether a crossing can be built, or another mitigation measure is suitable, will come down to a combination of soils, topography and the ability of a site to function as a wildlife crossing long-term. For any structure, the land on both sides of the highway must serve as wildlife habitat in perpetuity, whether through a conservation easement on private land or the presence of public land, depending on a priority site’s surroundings. Willing landowners and often the involvement of land trusts, are crucial for success.
The momentum toward addressing wildlife-vehicle collisions and other impacts of roads on ecosystems is growing in Montana and nationally. The Montana Department of Transportation is currently investigating safety and mobility needs through its U.S. 191/MT-64 Optimization Plan, and the federal Wildlife Crossings Pilot Program will accept applications in fall 2024 and 2025.
Wildlife Crossings Pilot Program grants require a 20% non-federal match, so strong public-private partnerships are essential to unlock 80% of project costs from federal funds. But the competitive grant program isn’t the only time-sensitive factor in pursuing crossings on U.S. 191.
“There is no ‘undo button’ for development,” says Fairbank. “The U.S. 191 area is developing, and the window of opportunity is closing to build a crossing in much of the northern part of the study area.”
Fairbank, who has participated in wildlife crossing projects in Montana, Wyoming and other western states, says that partnerships are key.
“The most successful efforts to stitch together fragmented landscapes and restore ecological connectivity with wildlife crossings happen when community leaders, citizens, scientists, public agencies, and nonprofit organizations work together with a common goal.”
The U.S. 191/MT-64 Wildlife and Transportation Assessment and subsequent work have been supported by area contributors, including Big Sky Resort Area District, Yellowstone Club Community Foundation, Moonlight Community Foundation, Turner Foundation, The Volgeneau Foundation, Weeden Foundation and Cinnabar Foundation.
Individuals interested in the findings of the US-191 Wildlife & Transportation Assessment and updates can learn more at largelandscapes.org/191
