Madison Valley: 
Identifying road kill hotspots to guide mitigation efforts

As a follow-up to our Bozeman Pass project and its success in reducing roadkill and increasing public safety, the Craighead Institute has begun work with the Montana Department of Transportation to initiate a similar project on US Highway 287 in the Madison Valley.

Madison Valley is situated in the Greater Yellowstone Ecosystem (GYE) and plays a key role in connecting this ecologically intact ecosystem to the other intact areas of the Central Rockies.  US Highway 287 forms a partial barrier for wildlife movement between protected lands around Yellowstone Park and a large intact block of core wildlife habitat on public lands that exists in the Gravelley, Snowcrest, and Centennial Mountains. As with Bozeman Pass, wildlife-vehicle collisions (WVC) along Highway 287 create both public safety and wildlife connectivity issues. Species of interest from a safety perspective are any large-bodied animal – pronghorn, bighorn sheep, mountain goat, deer, bear, elk, and moose. From a connectivity perspective, it is important to consider barrier effects that traffic imposes on elk, grizzly bear, pronghorn, wolverine and boreal toad, as these are species whose combined connectivity needs encompass those of all other species in the Madison Valley. 

To reduce risk to motorists, and to better understand areas of concern with regard to connectivity in the Valley, road mortality data needs to be systematically collected and mapped to elucidate patterns of WVC and identify hotspots.  Like with Bozeman Pass, these data can then be used to guide design modifications and mitigations that will allow wildlife to safely cross the highway. Improving safety and connectivity can be done now in a timely and cost-effective manner.  As time goes by, traffic volumes are likely to increase along with risk to motorists, and impacts on wildlife, if the road design is not improved.  Mitigations can be built into planned construction projects to minimize cost if data are available in the early planning stages. Wildlife habitat and connectivity modeling by the Craighead Institute and Wildlife Conservation Society (WCS) has identified three key areas for wildlife movement that should be the focus of data collection and highway improvement efforts - Norris Hill, Papoose Creek, and Raynolds Pass areas.

A body of research, including the Craighead Institute’s study on Bozeman Pass, supports the conclusion that properly located crossing structures, combined with wildlife fencing, can reduce or eliminate wildlife-vehicle collisions while increasing connectivity.  

Now that the project is approved, Craighead Institute and Western Transportation Institute staff is currently  setting up and conducting a systematic road kill survey of Highway 287 from Norris to Raynolds Pass for a two year period.  At the end of the project, data will be analyzed with an MDT biologist in order to develop a set of recommended mitigations at specific sites on Highway 287.