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Colorado’s Largest Wildlife Overpass Has Cut Animal-Vehicle Collisions by 91%

By Emma Taggart on October 29, 2026

Before North America’s largest wildlife overpass was built on a stretch of highway between Denver and Colorado Springs, an animal was hit by a vehicle almost every day. But in the 10 months since the overpass opened across Interstate 25 between Larkspur and Monument, just two animals have been struck—that’s a 91% drop.

The Colorado Department of Transportation completed the 209-by-200-foot bridge—called the I-25 Greenland Wildlife Overpass—in December 2025. The $15 million project was designed in collaboration between state engineers and wildlife biologists to help animals like elk, mule deer, and pronghorn move safely across one of Colorado’s busiest highways. The overpass spans six lanes of interstate traffic, connecting 39,000 acres of habitat on both sides of I-25.

“We are thrilled,” says Bridget O’Rourke, a spokesperson for Colorado Parks and Wildlife. “Wildlife overpasses and underpasses and funneling animals to have a safe path across the roads, it’s been statistically proven that it’s successful.”

While the overpass was built primarily for larger wildlife, trail cameras and surveys have also captured smaller animals making use of the crossing, including rabbits and northern leopard frogs. The Colorado Wildlife and Transportation Alliance is now studying the results to work out where future crossings could have the biggest impact. Six more projects are in the design phase, including Colorado’s first overpass built specifically to help Rocky Mountain bighorn sheep safely cross Colorado 40.

Starting in January, Colorado drivers will have the option to pay an additional $5 fee to help fund wildlife crossings across the state. The scheme is similar to the $29 Keep Colorado Wild pass, which has raised $146 million since its launch in 2023.

O’Rourke says, “With your $5, it might not sound like a lot, but it adds up, and it’s something our state genuinely cares about.”