Elk NetworkConstruction Underway for Idaho’s First Wildlife Overpass

General | August 25, 2023

A 12-mile stretch of Highway 21 in remote southwest Idaho is especially deadly for elk and mule deer. How deadly? Crews with the Idaho Transportation Department (IDT) and Idaho Department of Fish and Game gathered 77 deer and elk carcasses struck by vehicles between Idaho City and Lucky Peak, east of Boise.

After more than three years in the making, construction is underway between mileposts 10 and 22 on Idaho’s first wildlife overpass to improve the situation.

“We have a migrating herd of deer and elk that winter back and forth between their winter range and their summer range, and they have to cross State Highway 21,” Scott Rudel, Idaho Transportation Department environmental planner, told KTVB-TV. “But when they are crossing, they create a mobility issue between the motorists who encounter them.”

The final structure will range from 120 to 150 feet in length. Tall fencing will run parallel to the highway to funnel wildlife over the roadway. Crews previously built an underpass about a mile away and trap cameras show elk and deer are already using it.

“There are about 7,000 to 8,000 animals that winter on the Boise River Wildlife Management Area. The animals will cross back and forth,” Rudel told KTVB-TV.

Other partners include the Federal Highway Administration-Western Federal Lands Highway Division, U.S. Forest Service, City of Boise and the Rocky Mountain Elk Foundation, which contributed funding to the project.

Construction is due to finish by the fall of 2023.

Click here to watch a report about the overpass construction.

(Photo source: Idaho Department of Fish and Game)