Wildlife bridges and underpasses led to a dramatic decline in animal-related car crashes, according to Mark Lawler, a biologist for Colorado Department of Transportation.

The five underpasses and two overpasses that cross Colorado 9 south of Kremmling have reduced wildlife related crashes by almost 90 percent, Lisa Schwantes communications manager for CDOT said Thursday.

There are more than 30 passages, which vary in construction, across the state of Colorado, only two of them cross over the highway.

“They’re extremely important,” Jeff Peterson, wildlife program manager for CDOT, said. “When you get into conflicts with wildlife that raises the issue.”

Statistics obtained by CDOT show that from 2006 to 2016 on U.S. 160, in the area between Durango and Bayfield, there were 472 car-animal collisions, a large number of them involving mule deer.

According to Lawler, the number could be higher, however, since vehicle-wildlife collisions are often underreported.

An underpass crossing U.S. Highway 160 between Durango and Bayfield was completed in the fall of 2016 by CDOT. Photographs taken with a remote camera at the underpass show the passageway is being used by deer, coyotes, raccoons and other small animals.

“At the (Durango) underpass we’re seeing a large number of mule deer going through the structure daily,” Lawler said. “Animals are using the structure; we’re not just moving the problem.”

CDOT has teamed up with Colorado Parks and Wildlife to conduct a study identifying other key wildlife crossing spots throughout the state.

“We want to make sure that if were going to do it, we’re doing it right. That’s why we don’t just throw them in everywhere we can,” Peterson said. “Putting the correct crossing in the correct place for the species you want to get from one place to another — that’s where it gets tricky.”

Crossings can cost anywhere from $300,000 up to more than $1 million. The crossings are paid for by CDOT, using tax dollars. Even though the crossings can be expensive, the lack of them ends up being expensive as well since insurance companies estimate damages to vehicles from wildlife collisions averages about $4,000 per incident.

“Roads all over the state run right through these migration paths, when they go back and forth a lot of animals are hit on the highway every year,” Joe Lewandowski, spokesperson for Colorado Parks and Wildlife said. “We’re very enthused about how CDOT is paying a lot of attention to this. There are many many needs in transportation across the state and this is just one of them.”

According to Peterson, the newest one is a bicycle trail and wildlife crossing combination that goes through Colorado 9 south of Dillon.

“We are continually studying and reaching new ways and better ways to add permeability to the highway for wildlife,” he said.