Elk, pronghorn, mule deer, black bears, mountain lions and a variety of other species are now able to cross the I-25 Greenland wildlife overpass near Larkspur, which is North America's largest wildlife overpass.
In December 2025, the Colorado Department of Transportation completed construction of the structure, including covering the overpass surface with dirt and vegetation. The project was completed in less than a year, ahead of schedule and on budget.
This overpass spans six lanes of interstate traffic, connecting 39,000 acres of habitat on both sides of I-25 between Larkspur and Monument.
"Colorado is leading the way in reducing wildlife-vehicle collisions, and improving safety for both our motorists and wildlife," said Colorado Governor Jared Polis. "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," said Governor Polis.
"The I-25 Greenland wildlife overpass is critical to the safety of both wildlife and motorists," said Shoshana Lew, CDOT executive director. "The overpass is an essential component of the wildlife crossing system in this area, which is expected to reduce wildlife-vehicle crashes by 90 percent."
The overpass is strategically located to address the 3.7-mi. gap from other wildlife crossings and completes the wildlife crossing system of underpasses and fencing as a part of the I-25 South Gap project — which improved 18 mi. of I-25 from Castle Rock to Monument. Prior to the system being built, there was an average of one wildlife-vehicle crash a day in the fall and spring wildlife movement seasons. CDOT's research shows that the five underpasses are successfully being used by large and small mammals. However, the Greenland overpass was specifically designed and constructed to provide safe passage for elk and pronghorn. These species prefer wide open overpass structures.
The overpass location connects wildlife corridors and preserves open space with good proximity to water. The location also is a known area for high movement of large game.
A multi-agency partnership with the Federal Highway Administration, Colorado Parks and Wildlife, Douglas County, the Douglas Land Conservancy and the Colorado Cattleman's Agricultural Land Trust made the Greenland wildlife crossing possible. As part of the Wildlife Crossings Pilot Program, a federal grant award provided the bulk of the funding for the project.
"In Douglas County, we take great pride in being responsible stewards of our resources — including our natural spaces and wildlife," said Commissioner George Teal. "Since 1996, our county — in partnership with CDOT, Colorado Parks and Wildlife and FHWA — has been safeguarding the wildlife habitat along the I-25 corridor. The completion of this wildlife crossing is a tremendous milestone, and we congratulate everyone who has been a part of this effort, which also benefits public safety and transportation."
"After more than nine years of planning and work, Colorado Parks and Wildlife is excited for Colorado's wildlife to utilize this overpass," said Matt Martinez, CPW area wildlife manager. "We look forward to deer, elk, bears, mountain lions and many other species safely crossing I-25, once a major barrier to migration and wildlife movements.
"In collaboration with our partners at CDOT, Douglas County, Douglas Land Conservancy and other stakeholders, wildlife overpasses and underpasses along I-25 will reconnect large tracts of open space along the southern Douglas County I-25 corridor."
