Wildlife Collisions Fell 91% After Colorado Opened a Grass Bridge Over I-25

19 Oct 2026, 20:55 by Sari Moon · Thought Catalog

Colorado Department of Transportation

Updated 18 seconds ago, October 19, 2026

In the roughly 10 months since the Greenland Wildlife Overpass opened across I-25 between Larkspur and Monument, drivers have struck two animals. State wildlife and transportation officials put that at a 91% drop.

From 2013 to 2017, that same stretch averaged 32.2 reported wildlife-vehicle crashes annually. Over about four and a half years, drivers hit nearly 200 animals there, including 119 deer, 18 black bears, 10 mountain lions and one moose.

The Greenland Wildlife Overpass spanning I-25 between Larkspur and Monument, Colorado — a 200-foot-wide, soil-and-grass bridge CDOT calls the largest wildlife structure of its kind in North America. Credit: Colorado Department of Transportation.

The overpass opened in December 2025: a soil-and-grass deck 200 feet wide and 209 feet long, spanning six lanes that carry more than 100,000 vehicles a day. It cost $15 million, backed by a $22 million federal grant, connects about 39,000 acres, and CDOT calls it the largest wildlife bridge structure in North America.

It was built beside five underpasses because elk and pronghorn avoid tunnels. “We’re seeing elk herds cross the bridge. We’re seeing pronghorn for the first time in decades cross over to the west side of I-25 because of the bridge,” said Chuck Attardo, CDOT’s environmental manager for the corridor. “Animals are like people. They like choices.”

“They pay for themselves in about 15 years,” Attardo said, “because of all those accidents that they prevent.” Starting Jan. 1, 2027, Colorado drivers can add an optional $5 to their registration to fund more crossings.

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