The Idaho Transportation Department completed construction on the state’s first wildlife overpass this fall, and animals are already finding their way over the highway.

“We’ve gotten animals — particularly mule deer — on some still cameras. They seem to be crossing at night,” said Roger Phillips with Idaho Fish and Game.

Drone footage after a recent snowfall revealed tracks funneling toward the new SH-21 overpass between Lucky Peak and Idaho City. The project also included fencing along the highway to guide animals across.

Phillips said the fact that animals are using the crossing is a positive sign, but the infrastructure is still new for them. Some are ending up on the highway, so it’ll be important, he said, to watch that they learn this new habit.

“Where deer no longer feel comfortable crossing a major freeway or some kind of a barrier, then they will just quit migrating,” he said.

This is one of Idaho’s largest mule deer herds, he said. They winter in the lower elevation Boise River corridor and migrate up toward the Sawtooths in the spring. Elk numbers have been increasing in recent years, too.

There’s already a wildlife underpass on this road that was built in 2010, but state officials think the addition of the overpass will reduce vehicle collisions with big game by 80%.

The project, totaling about $6.5 million, was primarily funded by the Federal Lands Access Program within the Federal Highway Administration, but it was also supported by the Idaho Transportation Department, the Idaho Department of Fish and Game, the City of Boise and the Forest Service.

Other crossings are in the works or are planned for I-90 in North Idaho and US-30 in southeastern Idaho.

Find reporter Rachel Cohen on Twitter @racheld_cohen

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