DENVER — Colorado is on track to openDENVER — Colorado is on track to open what transportation officials say will be the “world’s largest” wildlife overpass, aiming to dramatically reduce dangerous animal-vehicle collisions along one of the state’s busiest highways.

The $15 million Greenland Wildlife Overpass is rising above Interstate 25 at Mile Point 165.4, just north of Monument — a critical corridor for migrating elk, mule deer, pronghorn and other large animals.

When finished, the crossing will stretch 209 feet over six lanes of I-25 and span 200 feet in width, connecting 39,000 acres of big game habitat in Douglas County with more than 1 million acres of the Pike National Forest.

Why It Matters

‍The goal is to make this high-traffic stretch — which sees roughly 85,000 vehicles a day — significantly safer for both drivers and wildlife. “The crossing is expected to curb vehicle-animal collisions along the corridor by 90%,” according to the Colorado Department of Transportation (CDOT).

More than 5,000 vehicle-wildlife crashes are reported every year in Colorado, costing the state about $80 million annually in vehicle damage, medical expenses and wildlife loss.

State of Play

‍The overpass is now halfway complete, with the project moving into its third of four phases, CDOT spokesperson Tamara Rollison told Axios Denver. The final phase of construction kicks off in September, with full completion targeted for December — just in time for winter wildlife movement.

Bigger Picture: A Statewide Push

‍Colorado is no stranger to wildlife crossings. CDOT has already built more than 100 animal crossings statewide, most of them underpasses and tunnels. But the Greenland Overpass represents a new scale for the state’s efforts — and a national model for how highways can be redesigned to reconnect fragmented habitats.

“It’s not just about saving wildlife — it’s also about protecting people,” Rollison noted. As Colorado’s population grows and daily traffic on I-25 rises — projected to hit 150,000 trips daily by 2040 — the need for safe wildlife routes across the Front Range will only increase.

What Drivers Should Know

‍Until the project wraps at the end of the year, drivers should plan for daytime and overnight lane closures, narrower lanes, temporary shifts, and slower speed limits through the work zone.

When complete, the overpass will give elk, deer, and other big game animals a safer route over I-25 — helping them follow seasonal migration paths that have existed for centuries but are increasingly disrupted by highways and development.

With the Greenland Overpass nearly halfway done, Colorado is sending a clear signal: in the race to balance growth with conservation, safe wildlife crossings can deliver big returns for both animals and drivers.

‍Why It Matters

‍The goal is to make this high-traffic stretch — which sees roughly 85,000 vehicles a day — significantly safer for both drivers and wildlife. “The crossing is expected to curb vehicle-animal collisions along the corridor by 90%,” according to the Colorado Department of Transportation (CDOT).

More than 5,000 vehicle-wildlife crashes are reported every year in Colorado, costing the state about $80 million annually in vehicle damage, medical expenses and wildlife loss.

State of Play

‍The overpass is now halfway complete, with the project moving into its third of four phases, CDOT spokesperson Tamara Rollison told Axios Denver. The final phase of construction kicks off in September, with full completion targeted for December — just in time for winter wildlife movement.

Bigger Picture: A Statewide Push

‍Colorado is no stranger to wildlife crossings. CDOT has already built more than 100 animal crossings statewide, most of them underpasses and tunnels. But the Greenland Overpass represents a new scale for the state’s efforts — and a national model for how highways can be redesigned to reconnect fragmented habitats.

“It’s not just about saving wildlife — it’s also about protecting people,” Rollison noted. As Colorado’s population grows and daily traffic on I-25 rises — projected to hit 150,000 trips daily by 2040 — the need for safe wildlife routes across the Front Range will only increase.

What Drivers Should Know

‍Until the project wraps at the end of the year, drivers should plan for daytime and overnight lane closures, narrower lanes, temporary shifts, and slower speed limits through the work zone.

When complete, the overpass will give elk, deer, and other big game animals a safer route over I-25 — helping them follow seasonal migration paths that have existed for centuries but are increasingly disrupted by highways and development.

With the Greenland Overpass nearly halfway done, Colorado is sending a clear signal: in the race to balance growth with conservation, safe wildlife crossings can deliver big returns for both animals and drivers.

Originally reported by Alayna Alvarez in Axios Denver.