WCS North America

Pronghorn Safe Passages

Each spring and fall, approximately 300 pronghorn (Antilocapra americana) make one of the longest mammal migrations in the lower 48 in order to access summer range in Grand Teton National Park and winter range on the Pinedale Anticline. Archaeological evidence suggests that these pronghorn have been migrating alongthis path, now known as the “Path of the Pronghorn”, for over 6,000 years.

Conservation Challenges

Today, the Path of the Pronghorn is the last existing pronghorn migration in and out of Grand Teton National Park. Approximately one half of the migration route crosses through the Bridger Teton National Forest; recognizing the importance of conserving this migration, this segment of the route was designated as the only federally recognized wildlife migration corridor in the United States.  Beyond the protection of the designated migration corridor on National Forest lands, private easements, and limited protection at Trapper’s Point, human activities on the landscape, including highways and housing developments, have severed other historic pronghorn migration routes. 

One bottleneck for pronghorn moving along this migration path is at Trapper’s Point, where riverine corridors and residential development constrict the route to a narrow intersection where thousands of animals are forced to cross U.S. Highway 191 (US 191). The highway crossing created a dangerous situation for humans and wildlife alike


Conservation Approach

WCS helped identify intersections between pronghorn migration corridors and US 191 where under and overpasses with fencing could guide pronghorn safely across the road and reduce wildlife vehicle collisions between pronghorn and motorists.  In 2010, the Wyoming Department of Transportation (WYDOT) used this information to invest $9.7 million along US191 to install fencing and crossing structures to protect both wildlife and highway travelers. In the fall of 2012, 8 wildlife crossing structures and 23 kilometers of fencing were completed and now successfully guide pronghorn and other wildlife safely under and over US 191, avoiding the risk of collisions with vehicles.


Long-distance migrations are one of the most essential and most threatened wildlife phenomena.  Unfortunately, few people have opportunities to see and appreciate the value of these seasonal migrations. The wildlife crossing structures at Trapper's Point span a busy highway south of Yellowstone and Grand Teton national parks.  This setting provides a unique opportunity for travelers to directly observe pronghorn and other species moving across the overpass, offering a unique opportunity for outreach to help build support for migration conservation.  WCS is leading an effort with partners to design and install an informative interpretive site that provides information on-site and on-line about this important ecological phenomenon and the infrastructure investments that have been made to conserve these migratory movements.


These new wildlife crossing structures are expected to reduce wildlife vehicle collisions by at least 80% and are anticipated to pay for themselves within 12 years by avoiding wildlife-vehicle collisions that would have incurred costs of the loss of wildlife, damage to vehicles, and injury to people. We are currently studying the effects of the structures and the adaptations of the pronghorn at Trapper’s Point in order to utilize lessons learned in other crucial wildlife road crossing locations around the world.


Our years of field research were pivotal in the effort to designate the first and only federal migration corridor in the U.S.  Further, this research informed the Wyoming Department of Transportation of the optimal locations for installing wildlife crossings and fencing to protect the migration and drivers.  More recently, our web camera was installed on the overpass and now provides a live look at real-time activity on the overpass.

Live video from the Trapper's Point Wildlife Overpass


 Project Partners (financial contributions marked *)

National Fish and Wildlife Foundation*, Wyoming Game and Fish Department*, Jackson Hole Conservation Alliance*, Water for Wildlife*, National Parks Conservation Association*, Wyoming Department of Transportation, Wyoming Migration Initiative, Pinedale Travel and Tourism Commission, Upper Green River Alliance, Grand Teton National Park, Western EcoSystems Technology, Inc., Green River Valley Land Trust, Bureau of Land Management, and Wyoming Office of Tourism*(pending).

Watch archived video of pronghorn crossing the Trapper's Point Wildlife Overpass, fall 2014


WCS North America Program
212 South Wallace Avenue, Suite 101 Bozeman, MT, 59715 USA
(406) 522-9333

Key Staff

Jon Beckmann
Connectivity Initiative Coordinator
Renee Seidler
Pronghorn Field Leader
All Pronghorn Field Program Staff >>

Partners Include

Water for Wildlife
Jackson Hole Conservation Alliance
National Parks Conservation Association
National Fish and Wildlife Foundation
Wyoming Game and Fish Department
Wyoming Migration Initative
Upper Green River Alliance