Colorado’s Greenland wildlife overpass is now the largest in the world
Colorado’s Greenland Wildlife Overpass, completed in December 2025, is now the largest wildlife crossing on Earth — nearly an acre wide and built to reconnect elk, pronghorn, and mule deer across one of the state’s busiest highways. The structure links 39,000 acres of conserved Douglas County land with over one million acres of Pike National Forest, restoring a migration corridor fragmented by Interstate 25. As part of an 18-mile system of crossings and fencing, it is projected to reduce wildlife-vehicle collisions by up to 90 percent. At 5 million, the investment is modest compared to the cumulative cost of doing nothing.









