California's first state-built wildlife overpass isn't finished yet — but the animals it was designed to help are not waiting. A trio of mule deer have already walked across the new structure, captured on camera in a moment that officials are calling a milestone for wildlife connectivity in the West.

The $20 million bridge spans a stretch of State Route 97 in Siskiyou County, near the Oregon border. It is the first wildlife overcrossing in California planned, funded, and built by Caltrans specifically to reconnect animal habitats — rather than as a side condition of another construction project.

A Camera Catches History

Nearly 100 wildlife cameras are installed in and around the overpass. In late May, one of them caught three mule deer ambling across the partially built structure, just 15 hours after crews wrapped up work for the day.

The UC Davis Road Ecology Center shared the image on June 2, prompting wide attention from wildlife groups and engineers.

"While the contractor is still completing final touches, it's incredible to see wildlife already embracing the new structure, even with workers still in the area," Caltrans wrote in a social media post. "Seeing animals use the structure this quickly is an exciting sign of the positive impact this project will have for both wildlife connectivity and public safety for years to come."

A Dangerous Stretch of Road

The overpass goes over a two-lane stretch of State Route 97 that has been one of the deadliest spots in the region for both animals and drivers. Between 2015 and 2020, more than 50 deer and 16 elk were struck and killed by vehicles along that corridor, according to data from Caltrans and the UC Davis Road Ecology Center.

The new structure aims to change that pattern. Miles of eight-foot-high fencing on either side will funnel animals toward the overpass and away from the asphalt.

Construction began in July 2025 and is expected to wrap up by this fall. The full design includes native vegetation across the top of the bridge to make the route feel like a continuation of the surrounding landscape.

Who Else Will Use It

While mule deer are the first confirmed users, biologists expect the crossing to benefit a much wider range of species. Mountain lions, black bears, and gray wolves all roam the region and could use the corridor to expand territories and find mates. A bobcat may have used the bridge in January, but officials have not been able to confirm that sighting.

Fred Shilling, director of the UC Davis Road Ecology Center, told reporters that the Siskiyou crossing is also notable because it was built proactively. Most wildlife crossings in the United States are mitigation requirements attached to larger highway projects. This one was designed from the start to reduce wildlife-vehicle collisions and reconnect fragmented habitats.

A Growing Movement

Wildlife crossings are gaining traction across the United States. Colorado, Wyoming, Utah, and Montana have all invested in over- and underpasses for elk, pronghorn, and other species. Caltrans is also building a much larger wildlife crossing over the busy 101 freeway in the Santa Monica Mountains, which is expected to open in 2026.

The Siskiyou bridge is a smaller, quieter version of the same idea — and a reminder that when humans build the right path, animals tend to find it remarkably quickly.