North America's Largest Wildlife Overpass Opens, Giving Elk a Safe Way Across
A 200-foot-wide wildlife overpass has opened across six lanes of Interstate 25 near Larkspur, Colorado — the largest in North America. The $15 million bridge connects 39,000 acres of habitat for elk, pronghorn, deer, bears and mountain lions, and is expected to cut wildlife-vehicle crashes by up to 90%.
EnvironmentGNGV Editorial Team4 min readLast reviewed September 28, 2026
For animals trying to cross one of Colorado's busiest highways, a daily gamble has been replaced by a safe path through the sky. Near Larkspur, between Denver and Colorado Springs, a vast new wildlife overpass now arches over six lanes of Interstate 25 — and at 200 feet wide and 209 feet long, covering roughly an acre, it is the largest such structure in North America. As Good News Network reported on March 28, 2026, the I-25 Greenland overpass opened to its first four-legged travelers after being completed ahead of schedule and on budget.
The bridge is the capstone of the wider I-25 South Gap Project, which already included five underpasses that mammals had begun using. Designed especially for elk and pronghorn — animals that need open space and a clear line of sight before they will cross — the overpass links some 39,000 acres of habitat split by the freeway. Beneath it, around 100,000 vehicles pass each day; above it, soil and native vegetation invite wildlife to move as if the highway were not there.
The safety case is stark. Before the crossing system was built, this stretch averaged about one wildlife-vehicle crash per day during the busy spring and fall movement seasons. Officials expect the completed network of overpass and underpasses to reduce those collisions by up to 90% — protecting drivers and animals alike. The $15 million project was funded largely through the federal Wildlife Crossings Pilot Program, in a partnership spanning state and federal agencies.
Wildlife crossings are quietly becoming one of conservation's most reliable success stories: where they are built, animals use them and deaths plummet. "Colorado is leading the way," Governor Jared Polis said of the milestone. The structure cannot, on its own, reverse habitat fragmentation across a fast-growing state — but it reconnects two halves of a landscape that traffic had severed, and it offers a replicable model. For every elk that walks safely over the interstate, it is proof that thoughtful engineering can let people and wildlife share the same crowded land.
