Matt Martinez

Built World

Tracking wildlife use of the crossings

Interstate 25 near Colorado's Greenland exit split 39,000 acres of habitat, and for decades elk and pronghorn could not cross it. The corridor averaged about one deer-vehicle crash per day in peak migration. In the overpass's first ten months, wildlife collisions dropped 91 percent, from a five-year average of roughly 40 a year to two.

Updated Oct 16