Crossing U.S. Route 20
From the northwest corner of Yellowstone National Park, U.S. Route 20 crosses the Continental Divide at Targhee Pass and winds its way south into Idaho, past the mountain streams and waterfalls of Caribou-Targhee National Forest.
Busy highways through natural areas usually spell trouble for wildlife, especially wide-ranging species like grizzly bears, elk and moose.
As they slice through the landscape, roads decrease available habitat and pose a constant danger to animals trying to cross them. Beyond those obvious dangers, highways also fragment wildlife populations into smaller, isolated sub-populations—a process that decreases genetic diversity and degrades the long-term health of any species.
But U.S. Route 20 is not just any highway. It’s the first major road that animals encounter as they roam west out of the protected lands of the Greater Yellowstone Ecosystem, and it bisects several known migration routes for elk and moose, which cross the highway twice yearly in the spring and fall. Other animals, such as grizzly bears, are also known to cross the highway throughout the year as well.
In 2015, Idaho Fish and Game, Idaho Transportation Department (ITD) and the Wildlife Conservation Society (WCS) teamed up to release a report, US 20 Island Park Wildlife Collision Study, which stressed the highway’s negative effect on wildlife movement.
Although wildlife-vehicle collisions occur along this entire stretch of road, the report’s authors identified several high-collision areas where wildlife fencing, crossing structures and other efforts could go a long way toward reducing wildlife-vehicle collisions overall.
With that and other studies revealing a clear call for action, several groups—including Y2Y, WCS and the Caribou Targhee National Forest—have come together to develop innovative ways to improve the highway.
Our collaborative effort involves identifying wildlife corridors to reduce wildlife-vehicle collisions, as well as determining the most effective structures (such as fencing and over- and underpasses) to serve that purpose, plus an education campaign to convince others of their overall importance.
Providing safe wildlife passage on U.S. Route 20 is a long-term vision. As the number of people visiting Yellowstone National Park and surrounding areas increases every year, so does traffic along this stretch of road.
Taking wildlife crossings into account for any future road upgrades is not only a boon for animals, but for drivers too. If done right, these efforts could serve as a positive example for countless other roadways bisecting ecosystems throughout the Yellowstone to Yukon region and beyond.