In May 2008, the Path of the Pronghorn became the first federally designated wildlife corridor in the United States. In 2012, a new overpass was constructed. ©From the video “Path of the Pronghorn.”

For nearly 6,000 years, pronghorn have made an annual migration from their summer range around the highlands of Grand Teton National Park to their wintering grounds, located about 170 miles south in the sagebrush-covered Upper Green River Valley near the town of Pinedale, Wyoming. But today, land development, large-scale energy enterprises, fences and roads are jeopardizing the ability of the animals to continue their traditional way of life.

The route the pronghorn take—one of the longest terrestrial mammal migrations in North America and the longest left in the Greater Yellowstone Ecosystem—is known as the Path of the Pronghorn. It became the first federally designated wildlife corridor in the United States on May 31, 2008. Unfortunately, U.S. Highway 191 cuts across that course in a very narrow and dangerous spot just west of Pinedale. Along a 12-mile stretch of road here, an average of 140 pronghorn and mule deer are killed each year.

In October 2012, a new, highway-crossing structure was built to help lessen the toll on the ungulates. The question, however, was: would the pronghorn be able to negotiate the newly designed overpass? The stakes were high; if the pronghorn balked, one of the West’s most iconic species could vanish forever from one of our most scenic national parks.

Watch the eight-minute video below, produced by NineCaribou Productions for the Wildlife Conservation Society. Discover what happened when the first group of pronghorn encountered the new overpass.

Here’s to finding your true places and natural habitats,