Wildlife crashes dropped 90 percent after the crossing opened

Wildlife-vehicle collisions have dropped more than 90 percent along an 18-mile stretch of Interstate 25 in Colorado, where officials finished a decades-long crossing system in December 2025. The final piece, a $15 million bridge near Monument, is the largest wildlife overpass in North America, spanning six lanes of a road that carries 100,000 vehicles a day. Before the fencing and underpasses, elk and pronghorn had few safe options. "It was an effective wall that they had to play Frogger and try to get across," said Brandon Marette, a wildlife biologist for Colorado Parks and Wildlife. The overpass runs 200 feet wide by 209 feet long, and the big animals took to it fast. For the first time in decades, pronghorn are crossing to the west side of I-25. Elk have ambled over on camera. Rabbits and northern leopard frogs have used it too. Since the bridge opened, two collisions have been reported along that stretch.