Mule Deer Make History on California’s First State-Built Wildlife Highway Crossing

In a promising event for wildlife in Siskiyou County, California, three mule deer were observed crossing a new wildlife bridge just hours after the completion of its initial construction phase. The overcrossing, designed to span State Route 97 near the Oregon border, aims to mitigate the frequency of dangerous wildlife-vehicle collisions that have plagued the area for years.

Officials from Caltrans District 2 shared the news on social media, highlighting that construction of the bridge began in July 2025 and is nearing its completion. The crossing has already gained attention from local wildlife, with the first confirmed users being the three mule deer captured on camera as they traversed the structure on May 24.

The overcrossing is being closely monitored by approximately 100 cameras set up by researchers from the University of California, Davis’s Road Ecology Center alongside personnel from Caltrans. These cameras provided valuable footage of the deer using the bridge, marking a significant milestone as it represents the first documented wildlife crossing on California’s inaugural overpass crafted specifically to aid animals traversing state highways.

Caltrans officials expressed excitement over the early signs of wildlife adopting the new infrastructure, despite ongoing construction. This enthusiasm was captured in a recent social media post, which noted, “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.” Additionally, a bobcat was also spotted using the overcrossing, further demonstrating its potential utility for various species.

Fraser Shilling, who heads the Road Ecology Centre at UC Davis, commented on the significance of the project. He stated, “This marks the first time wildlife have used the first-ever wildlife overcrossing in California. It heralds a new era of wildlife overcrossings to improve wildlife connectivity.” The project is particularly important given that the area has been identified as a hotspot for wildlife-vehicle incidents.

Between 2015 and 2020, data compiled by Caltrans and the Road Ecology Center revealed that more than 50 deer and 16 elk lost their lives along this corridor. The new overcrossing is expected to provide a safer passage for various species including gray wolves, elk, mountain lions, black bears, and, notably, mule deer.

What makes this project especially noteworthy is that it represents California’s first wildlife overcrossing that has been specifically planned, funded, and constructed by Caltrans to improve wildlife connectivity. Previous overcrossings in the state were often constructed as part of mitigation efforts linked to other projects rather than as a dedicated initiative.

The swift adoption of the structure by local fauna is seen as an encouraging early indicator of the positive long-term impact the bridge may have. “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,” Caltrans remarked.

As California continues to grapple with the challenges of coexisting with natural wildlife populations, this new crossing serves as a hopeful solution that could pave the way for similar projects across the state. It highlights a growing recognition of the need for infrastructure that accommodates both human and animal movement, ensuring safety and promoting ecological coexistence.