The Greenland Wildlife Overpass in Colorado is redefining how transportation infrastructure can coexist with wildlife.
Spanning six lanes of Interstate 25 in Douglas County, the newly completed structure is the largest wildlife overpass in North America and is designed to reconnect thousands of acres of habitat that were long divided by one of the region’s busiest highways.
For decades, the stretch of I-25 between Denver and Colorado Springs has cut through a key wildlife migration corridor. Elk, mule deer, pronghorn, bears, and mountain lions regularly move between seasonal habitats in the area. But crossing the highway was dangerous for animals and motorists alike. During peak migration seasons, the corridor averaged roughly one wildlife-vehicle collision per day.
The Greenland Wildlife Overpass aims to change that. The bridge measures about 200 feet wide and 209 feet long, covering nearly an acre of land and arching over the six-lane interstate. It is designed to look and function like natural terrain, with soil and vegetation covering the structure so animals can cross as if they were moving through the surrounding landscape.
By restoring this natural pathway, the overpass reconnects approximately 39,000 acres of habitat on both sides of the highway. Wildlife crossings like this are built to solve a growing ecological problem: habitat fragmentation. As highways, cities, and infrastructure expand, landscapes that once formed continuous ecosystems become divided into isolated patches.
Animals that depend on large territories or seasonal migrations may struggle to find food, reproduce, or maintain healthy populations when these connections disappear. The Greenland Wildlife Overpass provides a safe route across the interstate for a wide range of species. Large mammals such as elk and pronghorn are expected to be the most frequent users, but smaller animals, including foxes and coyotes, may also benefit.
To encourage wildlife to use the crossing, engineers designed the structure with open sightlines and gradual slopes so animals can see clearly across the bridge and feel comfortable crossing. The overpass is also part of a broader wildlife safety system built along this section of highway. The I-25 South Gap project includes additional wildlife underpasses and miles of fencing that guide animals toward designated crossing points.
Together, the system is expected to reduce wildlife-vehicle collisions in the corridor by up to 90%. That reduction would benefit both wildlife conservation and public safety. Collisions between vehicles and large animals can cause serious injuries, vehicle damage, and fatalities. Nationwide, such accidents cost billions of dollars annually in medical expenses, insurance claims, and infrastructure damage. By preventing animals from entering traffic lanes and giving them safe crossing points instead, wildlife overpasses help protect drivers while preserving animal migration routes.
Colorado has become a leader in wildlife crossing infrastructure. The state has already built dozens of crossing structures across highways, though most are smaller tunnels or underpasses. The Greenland Wildlife Overpass stands out for its size and scale. It fills a 3.7-mile gap between existing crossings, completing a wildlife movement network across the region.
More than 100,000 vehicles travel this section of I-25 each day, making it one of the busiest highways in Colorado. Without a safe crossing, animals attempting to migrate across the road faced a high risk of collisions.
Wildlife bridges, such as the Greenland Wildlife Overpass, represent a growing trend in ecological infrastructure. Similar crossings have been built in countries including Canada and the Netherlands, where vegetated bridges allow animals to pass safely over highways.
Studies show that when combined with fencing and other mitigation measures, wildlife crossings can dramatically reduce collision rates and help restore ecological connectivity. The Greenland Wildlife Overpass also demonstrates how conservation goals can be integrated into modern infrastructure projects. Instead of treating roads and wildlife habitats as competing interests, engineers and conservationists are increasingly designing solutions that support both transportation and biodiversity.
As highways expand and wildlife habitats become more fragmented, structures like this may become an increasingly important tool for protecting ecosystems. For animals migrating through the state’s foothills, the Greenland Wildlife Overpass in Colorado offers something simple but powerful: a safe path across a barrier that once divided their world.
