Now, the migrating antelope have a safer way to cross the highway—their own overpass. The wide new bridge was built to preserve the animals' historic migration route.
Wildlife underpasses on other Wyoming highways have reduced vehicle mortalities for deer and other wildlife by more than 80 percent in some areas. But pronghorn, who rely on their powerful eyesight and fast running speeds to escape from danger, are reluctant to walk into the low, dark underpasses, so they needed a different solution.
The overpass was a gamble: No one knew for sure if the antelope would actually use it. But as this picture by wildlife photographer and National Geographic Young Explorer Joe Riis shows, the antelope knew just what to do when they came to the overpass at Trappers' Point. Eight-foot-tall (2.4-meter-tall) game fences funneled the animals to the overpass, and they sprinted over and continued south toward their winter range.
The Wyoming Department of Transportation, after failing to get federal funding for the project, wrote the $9.7 million check for the Trappers' Point overpass, as well as another overpass, six wildlife underpasses, and fencing on both sides of this 12-mile (19-kilometer) stretch of Highway 191. The savings to the state and drivers from avoiding vehicle damage while saving the lives of deer, antelope, and other species will pay for the project in a dozen years.