AASHTO Journal - Colorado DOT Completes I-25 Greenland Wildlife Overpass

The Colorado Department of Transportation recently completed construction of the new I-25 Greenland Wildlife Overpass near Larkspur, which is among North America’s largest wildlife overpasses; work that included covering the structure’s surface with dirt and vegetation.

[Above photo by the Colorado DOT]

Some 76 girders hold up the deck of this overpass – completed in less than a year, ahead of schedule and on budget – which spans six lanes of interstate traffic and connects 39,000 acres of habitat on both sides of I-25 between the towns of Larkspur and Monument.

Colorado DOT said more than 100,000 vehicles a day travel this area and that the wildlife expected to use this overpass include big game animals such as moose, bear, mountain lions, elk, mule deer, and pronghorn deer – along with smaller animals as well.

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, Colorado DOT said.

[Editor’s note: The Wyoming Department of Transportation recently produced a video detailing some of the hazards posed when wildlife traverse highways and how state departments of transportation are working to mitigate those hazards.]

The overpass is strategically located to address the 3.7-mile 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 that improved 18 miles 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. Colorado DOT said its research shows that the five underpasses are successfully being used by large and small mammals.

“Colorado is leading the way in reducing wildlife-vehicle collisions and improving safety for both our motorists and wildlife,” noted Governor Jared Polis (D) in a statement. “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.”

“The I-25 Greenland wildlife overpass is critical to the safety of both wildlife and motorists,” added Shoshana Lew, Colorado DOT’s 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.”