Idaho invested in their first and only wildlife overpass in November 2023 – and one year later – the $7.5 million project is proving to be a success.
The goal of the overpass was to reduce vehicle and animal collisions by 80%. Since the overpass has been standing, there have been zero vehicle and animal collisions on the stretch of the project.
“This project is all about collaboration – the name of safety and mobility for our drivers and motors, you and I, your families, our friends, everybody in Idaho that uses this as well as the wildlife in Idaho,” said Scott Rudel, environmental planner with Idaho Transportation Department.
The overpass sits just north of Lucky Peak – about a mile past an existing underpass that was built in 2010 – also for wildlife. Around 9,000 mule deer and 2,400 elk cross that exact stretch of Highway 21 with their migration patterns – leading to serious collisions on the road.
"The animals are going back and forth all through late fall, winter and early spring, before they go back to their summer or winter habitat,” Rudel said.
In the last five years, before the overpass was built, there have been four “serious” collisions between vehicles and animals on Highway 21 where the wildlife migrate, Rudel said, causing a need for more resources.
“They both do one thing, and the main thing is to provide permeability across the busy highway corridor,” Rudel said.
The Federal Highways Administration's Federal Lands Access Program helped fund the project -- and ITD just won a President's Award for Environment and Planning through the American Association of State Highway and Transportation.
While they don't have specific numbers, through video evidence and prints on the overpass, Rudel said it’s clear mule deer and elk are using the overpass.
“We know that it's been working,” Rudel said.
Neighbors who live near the overpass said they see deer and elk frequently – and know to be careful on Highway 21 to not hit them.
“They're crossing right before dusk and then right before the sun goes down,” said Tammy Thornton, who lives north of the overpass.
She said she still sees several elk near her property – not within the designated fencing area to lead wildlife to go across the overpass. Brian Pearson, with Idaho Fish and Game, said they are looking to expand the fencing in order to accommodate for that.
"One of the improvements that we're looking at is improving the fencing and extending the fencing to continue to direct animals to use the overpass structure,” Pearson said.
Right now, the fencing only covers about a mile of Highway 21. With expanded fencing, it would cover about four miles of land, Rudel said.
"We've got another phase of fencing that's going to be coming through in the next year,” Rudel said.
Other cities across Idaho are also looking at adding a wildlife overpass to their busy roads. Rudel said ITD is proposing one across U.S. 30, near Rocky Point.
“They have kind of a similar issue where mule deer migrate from their summer range across U.S. 30 to kind of winter range along the wildlife management area down there,” Rudel said.
With new projects in the works to improve the existing overpass and add new ones throughout the state, Rudel said the main goal is safety – for drivers and animals.
“It's for all the generations to come of Idahoans and it's important,” Rudel said. “It's important for everybody in Idaho to know that it's their wildlife and it's their wildlife crossing.”