Idaho Lawmakers Pass Resolution Supporting Wildlife Crossings and Habitat Connectivity

Article March 24, 2026

Two mule deer stand amid dry brush in front of a wire fence looking toward a two-lane highway, as a semitrailer with an orange cab speeds along the road. — Mule deer pause by a fence along U.S. Highway 30 in southeast Idaho. The state plans to begin construction of wildlife underpasses and fencing in the area in 2026 to help prevent collisions between motorists and animals.

In 2025, Idaho was the nation’s second-fastest growing state by population percentage. More people mean more drivers on the road, which, in a state rich in iconic wildlife such as mule deer, elk, and moose, also means a greater risk of collisions between vehicles and wildlife as these animals migrate between their habitats. On average, Idaho experiences more than a thousand of these crashes each year on its highways at an estimated annual cost of nearly $150 million.

Idaho lawmakers have taken notice of this problem and have outlined a set of solutions. Earlier this month, the Legislature passed Senate Concurrent Resolution No. 124, which supports investment in wildlife crossing infrastructure such as overpasses and underpasses that are proved to keep roads safer, reduce accidents, and support important wildlife populations. The resolution is a meaningful step toward reducing wildlife-vehicle collisions and addressing the habitat fragmentation—development, including roads, energy exploration, and residential construction, that can impede or block vital routes for species—that puts drivers and animals at risk.

View along a highway looking through a tunnel that runs under a large brown masonry bridge, topped with high fencing, that extends beyond the roadway on both sides. The sky above is blue with puffy white clouds. — Idaho’s Cervidae Peak Wildlife Overpass features fencing on either side of the highway to help funnel wildlife to the crossing.

This legislative momentum is also backed by the success of a recently completed wildlife crossing project. In 2023, the Idaho Transportation Department finished construction of the Cervidae Peak Wildlife Overpass over State Highway 21 near Boise. The overpass, which is the first of its kind in the state, is a roughly 150-foot-long bridge designed with natural terrain that guides elk, mule deer, and other migrating animals away from the highway. Department officials expect the overpass to reduce collisions between animals and the highway’s 14,000 daily drivers by 80%.

Five mule deer walk on a grassy overpass with fencing visible behind them and mountain peaks and a pale pink sky in the background.

The Cervidae Peak overpass provides a crucial link in the biannual migration of more than 8,000 mule deer, elk, and antelope. In winter, these animals use the overpass to move to Boise River Valley, avoiding the deep snow in the central Idaho mountains. They return to higher elevation habitats in the spring, where the temperature is cooler and they have access to more vegetation.

The decline in mule deer numbers across most of the Western U.S. highlights the need for crossings and other solutions to habitat fragmentation. Thankfully, Idaho’s elected leaders are taking proactive steps to address public safety and wildlife conservation. Senate Concurrent Resolution No. 124 sends a clear signal that Idaho’s lawmakers are ready—in keeping with the state’s proud tradition of practical problem solving—to move forward on wildlife crossings with support from local communities who see the need firsthand.

Nic Callero works on The Pew Charitable Trust’s U.S. conservation project.