The Colorado Department of Transportation (CDOT) has finished building the I-25 Greenland Wildlife Overpass near Larkspur, now recognized as the largest wildlife overpass in North America. The project, which included covering the structure with dirt and vegetation, was completed ahead of schedule and within budget.
Spanning six lanes of interstate traffic, the overpass connects 39,000 acres of habitat on both sides of Interstate 25 between Larkspur and Monument. This location is significant for local wildlife movement, including elk, pronghorn, mule deer, black bears, and mountain lions.
Governor Polis commented on the project’s significance: “Colorado is leading the way in reducing wildlife-vehicle collisions, and improving safety for both our motorists and wildlife. The I-25 Greenland wildlife overpass is a momentous feat, in our continued work to expand safe transportation options for both humans and wildlife, protecting critical habitat and our amazing outdoor spaces for generations to come.”
CDOT Executive Director Shoshana Lew highlighted the safety benefits: “The I-25 Greenland wildlife overpass is critical to the safety of both wildlife and motorists. The overpass is an essential component of the wildlife crossing system in this area, which is expected to reduce wildlife-vehicle crashes by 90%.”
The overpass addresses a 3.7-mile gap from other existing crossings along I-25 and completes a system that includes underpasses and fencing as part of the broader I-25 South Gap project. This larger effort improved an 18-mile stretch from Castle Rock to Monument. Before these measures were implemented, there was an average of one collision involving wildlife each day during peak migration seasons.
Research by CDOT shows that five underpasses are already being used by various mammals; however, this new overpass was designed specifically for elk and pronghorn that prefer wider open crossings. Its placement preserves open space corridors with access to water sources—areas known for high activity among large game species.
