Crossing in Progress
- 7 days ago
- 3 min read
By Andrew Xie Feb. 11, 2026
In December 2025, the Colorado Department of Transportation (CDOT) celebrated a historic milestone in both wildlife protection and roadway safety with the completion of the Greenland Wildlife Overpass in Douglas County, officially the largest wildlife overpass in North America. The overpass was constructed as part of the Interstate 25 (I-25) South Gap Project, a CDOT initiative launched to refine an 18-mile stretch of the highway between the towns of Castle Rock and Monument. Spanning six lanes of traffic on I-25, the overpass provides elk, deer, bears and many other species safe passage across a highway that once severed their habitat.
“Protecting our nation’s wildlife should be a priority when building highways. We share this planet, so highways should not just take into account cars, but also animals and the habitats that they pass through,” Sophomore Elijah Yoon said.
Before the overpass was built, the stretch of I-25 was responsible for one wildlife-vehicle collision every day during peak migration seasons, per Forbes, as the highway cuts through a key ecological point where animals migrate between high-altitude ranges in the summer and lower ground in the winter. The result over the years: millions of dollars in property damages, numerous human injuries and thousands of animal deaths. Although the area already had several underpasses, elk and pronghorn tended to avoid these confined spaces. Rather, they prefer the wide, open sightlines provided by overpasses to maintain their high running speeds and scout for predators.
The structure was designed not just to serve as a road allowing animals to cross I-25, but also to feel and seem like a natural, continuous extension of the earth. The bridge measures approximately 200 feet wide and 209 feet long—covering just over 41,800 square feet—and provides nearly an acre of land to traverse on. Furthermore, the gently sloped arch is layered in several feet of soil along with native plants, grasses, shrubs and trees, mimicking natural terrain to facilitate crossing.
The overpass reconnects once-fragmented landscapes: 39,000 acres of Greenland Open Space on the east with more than one million acres of the Pike National Forest to the west. By connecting these habitats, it restores migration paths for herds between seasons. Although the bridge serves a variety of species, the wide, open overpass is specifically designed for larger animals like elk and pronghorn. The overpass will also be used by black bears, mountain lions, coyotes and various small mammals, allowing herds to reach seasonal food sources and breeding grounds safely, ensuring biodiversity in the area for future generations.
“Biodiversity is about protecting entire ecosystems, not just individual species. That is why the construction of this overpass is so significant. It keeps migration routes safe and accessible, helping make sure these ecosystems can survive and flourish for future generations,” Junior Kyuwon Yeom said.
The project was brought together through the collaboration of various state agencies, with CDOT leading the construction and engineering of the crossing. Colorado Parks and Wildlife provided the biological data, while Douglas County and the Federal Highway Administration provided much of the funds necessary through the Wildlife Crossings Pilot Program, a federal grant program aimed at reducing wildlife-vehicle collisions. The crossing was completed with a budget of approximately $15 million, a cost that is predicted to be offset by long-term savings—emergency responses, vehicle and structure repairs and medical bills—associated with an expected 90% decrease in wildlife-vehicle crashes, according to Colorado Governor Jared Polis.
As the current largest overpass in North America, the Greenland Wildlife Overpass has already set the precedent for future projects. Already, California is working on the Wallis Annenberg Wildlife Crossing on U.S. 101, which is expected to surpass the size of the Greenland Crossing upon its completion this year. As highways continue to be built across the country, the Greenland Crossing stands as a model for how infrastructure development can coexist with environmental protection, protecting both people and wildlife alike.
About the Contributors
Andrew Xie
staff writer
Andrew Xie is a sophomore at Leland High School and the Sports and Opinions Page Editor for The Charger Account. When he's not sleeping in on weekends, you can find him playing video games, watching movies, or hanging out with friends.
Krio Moon
artist
Krio Moon is a junior at Leland and an artist for The Charger Account. Outside of school, she likes to play tennis, watch superhero movies, and read books.
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