Colorado has officially completed construction of the I-25 Greenland wildlife overpass near Larkspur, marking the opening of North America’s largest wildlife overpass and a major milestone in the state’s efforts to reduce wildlife-vehicle collisions and protect critical habitat.
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Finished earlier this month by the Colorado Department of Transportation, the project includes a fully vegetated crossing surface designed to resemble the surrounding natural landscape. The overpass was completed in less than a year—ahead of schedule and within budget—and now allows elk, pronghorn, mule deer, black bears, mountain lions and other species to safely cross Interstate 25.
Spanning six lanes of traffic, the structure reconnects approximately 39,000 acres of habitat on both sides of I-25 between Larkspur and Monument, restoring a vital wildlife corridor that had long been disrupted by highway traffic.
“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,” said Governor Jared Polis.
CDOT officials emphasized the project’s safety benefits, noting that wildlife crossings are proven to significantly reduce crashes involving animals.
“The I-25 Greenland wildlife overpass is critical to the safety of both wildlife and motorists,” said CDOT Executive Director Shoshana Lew. “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 Greenland overpass fills a key 3.7-mile gap between existing wildlife crossings and completes the broader wildlife mitigation system built as part of the I-25 South Gap project, which improved 18 miles of interstate from Castle Rock to Monument. Before the system was installed, the corridor averaged roughly one wildlife-vehicle crash per day during peak migration seasons in spring and fall.
While five underpasses in the area are already being used successfully by both large and small mammals, the Greenland structure was specifically designed for species such as elk and pronghorn that prefer wide, open crossings rather than enclosed tunnels. The site was selected based on known wildlife movement patterns, proximity to water, and its role in connecting preserved open space.
Local and state leaders highlighted the long-term planning and collaboration behind the project. A multi-agency partnership involving the Federal Highway Administration, Colorado Parks and Wildlife, Douglas County, the Douglas Land Conservancy and the Colorado Cattleman’s Agricultural Land Trust helped bring the crossing to completion, with a federal Wildlife Crossings Pilot Program grant providing most of the funding.
“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.”
Colorado Parks and Wildlife officials said the overpass represents nearly a decade of planning and coordination.
“After more than nine years of planning and work, Colorado Parks and Wildlife is excited for Colorado’s wildlife to utilize this overpass,” said CPW Area Wildlife Manager Matt Martinez. “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.”
Measuring 200 feet wide and 209 feet long, the structure covers nearly an acre and is supported by 76 girders. More than 100,000 vehicles travel this stretch of I-25 daily, underscoring the overpass’s importance for both wildlife conservation and roadway safety as Colorado continues to invest in large-scale wildlife infrastructure solutions.
Originally reported by Colorado Government.
