Wildlife overpasses examined near Island Park

Contractor crews start installing sections of the eastbound portal of the wildlife overcrossing on Interstate 90 east of Snoqualmie Pass in Washington state in this Aug. 22 photo. The Idaho Transportation Department is considering similar wildlife overcrossings among options for improvements of U.S. Highway 20 as it approaches West Yellowstone. Washington State Department of Transportation

An artist’s rendering of a wildlife overcrossing on Interstate 90 east of Snoqualmie Pass in Washington state. The Snoqualmie Pass in the rendering is under construction. The overcrossing is scheduled to be complete in 2019. Washington State Department of Transportation

The Idaho Transportation Department is reviewing options for the improvement of U.S. Highway 20 as it approaches West Yellowstone, Mont., and it could mean a safer future for area migratory wildlife and motorists alike.

But the notion of wildlife overpasses near Island Park has also seen a backlash, where some have cast the idea as part of a United Nations’ conspiracy.

Highway 20, particularly between Idaho Falls and Rexburg, has seen a burst of improvements over the past few decades, including expansions and replacing stop-signed intersections with overpasses and interchanges. But the section north of the city of Chester, which extends 53 miles to the Montana border, has seen fewer improvements.

ITD has $22 million to be spent on improvements to a 4-mile stretch from the intersection of Highway 20 and Idaho 87 and the Montana border.

“The highway is old and beyond its useful life,” ITD Project Manager Eric Verner said. “It needs to be replaced, and we can improve it as we’re working.”


ITD has outlined four alternatives. The first, the most bare-bones option, would simply replace the pavement on Highway 20.

The second would replace the base underneath the road, known as ballast, as well as the asphalt, and it would involve construction of three wildlife overpasses, along with fencing along the stretch of road meant to funnel animals into the crossings. It would also involve additional passing and climbing lanes, cutting back trees where they shade the road in order to reduce ice in winter, and wider shoulders for bicyclists and pedestrians.

The third includes all the road improvements from the second alternative, but includes only warning signs for wildlife crossings. The fourth would add a single wildlife overpass with more limited fencing, along with signs and other wildlife protection measures.

ITD is moving through environmental assessments and evaluating the cost and efficacy of all four alternatives, holding several recent meetings in the Island Park area.

Verner said preliminary comments from the community put significant emphasis on doing something to reduce the number of collisions between wildlife and vehicles.

Verner said police reports were filed for 15 wildlife collisions in the area over a four-year period, but that likely significantly under counts the total number of accidents. In many cases, motorists hit an animal but don’t report it. And if the animal makes it to tree line before dying, it’s unlikely the accident will ever be reported.

Renee Seidler is Idaho Fish and Game’s statewide transportation specialist. She said the section of road near the Idaho-Montana border isn’t just bad for cars, but also for the rich local ecosystem.

“U.S. 20 through the Island Park region is pretty detrimental to our wildlife, not only including collisions, which are above average, but also in terms of fragmentation,” she said.

The area is a key crossing for wolverine and other predators, as well as for deer, elk and moose.

“It’s pretty common knowledge that this is a really important area,” Seidler said. “U.S. 20 sits on the boundary of Yellowstone and the High Divide region.”


Kim Trotter is U.S. Program Director with Yellowstone to Yukon, an environmental group that works in the U.S. and Canada with the goal of ensuring free wildlife passage throughout a large section of the northern Rockies.

“We’re not talking about making everything wilderness, but instead, how do we create a permeable landscape?” Trotter said.

“If we want to see wildlife thrive as the world around us changes, we need to make sure there’s habitat connectivity.”

Trotter said overpasses in other areas, notably near Banff National Park in Canada, have made great strides toward connecting fragmented populations of wildlife. More than 300,000 wildlife passages have been documented there, and the number has steadily risen as animals have become more accustomed to using the overpasses.

“It’s been hugely successful,” she said.

Now, she said, there are documented instances of collared female grizzlies using the crossings many times per day with cubs in tow.

“They’re having breakfast on one side, crossing over for lunch, and coming back for dinner,” she said.

Kathy Rinaldi is the Idaho conservation coordinator for the Greater Yellowstone Coalition. The group has long worked to preserve wildlife in the Yellowstone ecosystem, and it sees the proposed overpasses as important both for motorists and wildlife.

Rinaldi said Highway 20 currently divides summer and winter ranges for two large elk herds, so the entire herds have to cross the highway at least twice per year.

Another danger for wildlife, Rinaldi said, is that as traffic gets heavier and the road gets wider, it presents a greater obstacle for migrating wildlife. At some point, there’s enough traffic that they won’t cross the road, leaving them isolated from part of their seasonal range. It also fragments population, leaving small pockets of wildlife that don’t have much exchange of genetic material with outside animals, which can leave them weaker.

Seidler said measures such as wildlife crossing signs do nothing to make roads more permeable to wildlife, but overpasses have been very successful.

“As long as they are built with fencing, past studies show them to be 80 to 100 percent in reducing wildlife/vehicle collisions, which is phenomenal,” she said.

Agenda 21

Many in the Island Park area are on board with wildlife overpasses. Jean Bjerke has lived part-time in Island Park with her husband since 1999.

“I love Island Park,” she said. “It’s a little piece of heaven.”

Bjerke said there’s been a long-standing problem with wildlife collisions on Highway 20, with large roadkill found regularly. And for Bjerke, a wildlife photographer, those collisions are a threat to what brought her to the area.

“Everything I’m about as a photographer is photographing the beauty of nature,” Bjerke said. “My concern is for the wildlife, not my photography business. I want my grandchildren to have the chance to see a moose. I want them to have a chance to be in Island Park and see a grizzly bear.”

However, there has also been a small campaign against the wildlife overpasses driven by individuals ideologically aligned with the further-right corners of the tea party and the John Birch Society. The campaign includes a six-part series in the Gem State Patriot News, a website aligned with the tea party. That series, which was circulated locally, claims to link proposed wildlife overpasses to a secret United Nations agenda to force people to leave the country and inhabit cities.

“The true agenda is pushing us off our land into cities, taking control of our resources, and dictating how, if at all, we can use what is rightfully ours,” the Gem State Patriot News wrote.

Others have explicitly invoked Agenda 21, a little thought-of, nonbinding statement of support for sustainable development signed by the U.S. and many other counties in 1992 that has become favorite fodder for conspiracy theorists.

“There is a very small local group who oppose wildlife safety measures for reasons I find difficult to understand,” Bjerke said.

Reporter Bryan Clark can be reached at 208-542-6751.