In May 2008 the Bridger-Teton National Forest designated a strip of land along the Gros Ventre Range an official pronghorn migration corridor. This action marked the culmination of long-standing advocacy efforts by the Wyoming Outdoor Council and its conservation partners to protect an important migratory pronghorn route. Pronghorn that summer in the Grand Teton National Park and Jackson Hole area travel to wintering areas in the Green River Basin each fall in the longest terrestrial animal migration in the lower 48 states–a round trip journey of approximately 340 miles. Much of their route passes through Bridger-Teton National Forest and Bureau of Land Management lands. The pronghorn’s route is constricted by four bottlenecks–areas where topography, vegetation, development, and other landscape features, restrict the animals’ passage. The best-known bottleneck occurs at Trappers Point, where the pronghorn’s route is constricted by encroaching subdivisions to a width of approximately half a mile. Designation of the Bridger-Teton’s portion of the migration corridor is a tremendous step in protecting the pronghorn’s migratory route. However, approximately 105 fences cross the pronghorn’s path and as many as 15,000 oil and gas wells could be drilled in the Upper Green River Valley in the next few decades. Therefore, the Wyoming Outdoor Council will continue working to protect what remains of the pronghorn’s corridor, particularly in areas that are experiencing intensive energy development and urbanization.
While the plight of the pronghorn has highlighted the concerns about migratory corridors in Wyoming, many other wildlife migration routes also face development pressures. Mule deer migrating between winter and summer ranges in the Atlantic Rim area in south-central Wyoming encounter rapidly expanding oil and gas development infrastructure. Mule deer from the Wyoming Range herd in western Wyoming suffer high losses as they cross a stretch of highway that bisects their migration corridor (although new underpasses have mitigated this threat).
Whereas many big game migration corridors between traditional summering areas and critical wintering range are widely known in Wyoming, few migration corridors have been identified for non-big game species in the state. For example, little is known about avian and bat migration corridors in Wyoming. Nevertheless, garnering such knowledge will become critically important as wind farms become increasingly prevalent across Wyoming’s landscapes. If wind farms are improperly sited they can exact a heavy toll on migratory birds and bats. The Wyoming Outdoor Council works with agencies and other entities throughout Wyoming to help protect wildlife migration corridors and critical habitats from development pressures.