Once controversial highway program is now massive success story

Shown to reduce roadkill, wildlife crossings designed to help animals cross busy roadways may also help them navigate the climate crisis

Crossing the great divide: In Washington, animals are learning how to safely navigate highways like I-90. Photo: WSDOT

By K.C. Mehaffey. March 9, 2023. When Josh Zylstra saw the video clip of a cougar sauntering through the deep snow at the exit of a wildlife crossing on Washington’s Snoqualmie Pass on Jan. 2, he rushed it off to a colleague to post on Twitter and watched the excitement unfold.

As a biologist for the Washington State Department of Transportation (WSDOT), it’s part of Zylstra’s job to look through the thousands of video clips that come to his inbox annually from motion-sensor cameras set up at 11 wildlife crossings on a seven-mile stretch of Interstate 90.

Last year, there were close to 5,000 crossings—mostly deer, elk, coyotes and a multitude of smaller animals that are snowshoe hare-sized or larger.

But so far, the cameras have captured only one other cougar using a wildlife crossing on this major east-west highway.

“It was very exciting to see that. It’s not something we normally see,” says Zylstra of the cougar crossing.

He knows by following the research done in Canada’s Banff National Park, where there are 55 crossings in 50 miles of the Trans-Canada Highway, that it takes some animals years to get used to a new wildlife crossing.

It appears that cougars living near I-90 are becoming more accustomed to these man-made structures that—when combined with the appropriate fencing—help wildlife travel safely across roads and highways without being hit by a vehicle.

When the I-90 Wildlife Corridor Campaign kicked off in Washington in 2000, the project was controversial because of its high cost and questions about the effectiveness of crossings. The structures alone range from $500,000 to $6 million each.

But they’re now widely supported as the best way to reduce collisions and prevent unnecessary injuries and deaths to both animals and humans, not to mention the cost of damage to vehicles.

A recent Washington State University study found that on average, the crossings prevent one to three wildlife-vehicle collisions per mile each year.

Tool in battle against climate change

To wildlife advocates, the crossings are also important for connectivity. They allow wild animals to travel from winter to summer ranges or make their daily trek to and from watering holes, and help prevent populations from becoming genetically isolated.

Now, with the climate crisis impacting wildlife habitat, wildlife crossings are being seen as a vital tool to help wild animals be more resilient to the changes.

According to the Center for Biological Diversity, habitat loss and fragmentation are the primary drivers of the massive extinctions expected to come with climate change.

Cool look: Planners around the world have studied Canadian crossings, such as this one along the Trans-Canada Highway from Banff to Lake Louise. Photo: Adam Fagen/Flickr

“Roads and poorly planned development have profoundly negative impacts on biodiversity and ecosystem function, both of which are deteriorating worldwide,” the Center for Biological Diversity says. “Road kill numbers demonstrate the need for improved connectivity. For example, traffic is estimated to kill millions, if not billions, of animals on U.S. roads every year.”

On Feb. 14, the Center for Large Landscape Conservation and more than a dozen other organizations went a step further, issuing a statement urging government officials to consider climate change in the design of wildlife crossings.

“As effective as wildlife crossings can be, their siting and design too often fail to account for climate impacts. Incorporating these considerations is increasingly important to support climate-driven wildlife movements and range shifts,” their statement says.

Oregon behind the curve

Once they were shown to be effective, some western states quickly embraced wildlife crossings.

According to the Oregon Department of Transportation (ODOT), Colorado has 69 wildlife crossings; California and Utah each have 50; and Washington and Nevada have close to two dozen each. Oregon is lagging, with just six.

The Wildlands Network reports that Oregon drivers have a 1-in-180 chance of hitting an animal—the highest likelihood among West Coast states.

This session, the Oregon Legislature is considering House Bill 2999, which would establish a program to reduce wildlife-vehicle collisions, including feasibility studies and plans that may include wildlife crossings and roadway fencing.

Cidney Bowman, ODOT’s wildlife passage program leader, says Oregon drivers hit about 6,500 animals every year. The vast majority are deer and elk, but bear and cougars are also struck. Smaller animals aren’t generally recorded, she says.

Right this way, deer: Underpass in Montana along U.S. Highway 93. Photo: Confederated Salish and Kootenai Tribes, Montana Department of Transportation, Western Transportation Institute

ODOT has developed a map to pinpoint the areas where animals are most often struck.

The agency has also completed five undercrossings on Highway 97, south of Bend, and wildlife collisions there have dropped by about 86%.

But Bowman says the state hasn’t yet determined what projects to do next, partly because of the many complexities.

Along with extensive fencing, each project involves working with landowners on both sides of the roadway, and determining whether a more costly overcrossing is needed, or an undercrossing will do.

In addition to animals, people have been utilizing the Highway 97 crossings, which can deter wildlife, creating yet another consideration for future projects.

“We’ve learned a lot from the projects we have done,” Bowman says.

Crossings on I-5 planned

High cost has been the biggest impediments to building more wildlife crossings. But that’s changing.

Last year, the Oregon Legislature allocated $7 million in general funds to be invested in wildlife corridor projects. ODOT is hoping much of the allocation can be used as matching funds to get larger grants though a new federal program.

The Wildlife Crossings Pilot Program will spend $350 million over the next five years to help fund the design and construction of wildlife crossings across the country.

The bill—which is part of the federal Infrastructure Investment and Jobs Act—says that the cost associated with wildlife-vehicle collisions is estimated at $8.3 billion nationwide.

“Wildlife-vehicle collisions are a major threat to the survival of species, including birds, reptiles, mammals and amphibians,” it states.

On the road again: Blind curves, poor weather and darkness contribute to the deaths of hundreds of bears each year on U.S. roadways. Photo: National Park Service

Amy Amrhein, co-coordinator for the Southern Oregon Wildlife Crossing Coalition, is hoping ODOT will get about $20 million from the federal grant program to start building crossings along a 14-mile stretch of Interstate 5 between Ashland and the California border.

Daily, roughly 17,000 vehicles travel this stretch of highway that cuts through the Cascade-Siskiyou National Monument. The area is known for its biodiversity, which is a connecting point between the Coast Range and the Klamath Mountains to the west, and the Cascade Range and the High Deserts to the east.

Amrhein—who previously has worked for Sen. Jeff Merkley, D-Ore.—says that the coalition formed at the beginning of 2021, and has made great strides in a short amount of time.

“A bunch of us had been focused on connectivity in the region for a long time,” says Amrhein. “When we started to hear President Biden talk about an infrastructure bill, we felt like there would be potentially new money for wildlife crossings.”

So they formed the coalition and got the support of 17 organizations and agencies ranging from hunting and backcountry associations to conservation groups. The Oregon Wildlife Foundation—a coalition member—provides its nonprofit status. 

The coalition then raised about $130,000 to fund a design study that identified two overpass locations and six culverts or underpasses.

Amrhein says they wanted to be “shovel-ready” to vie for the new funding.

“So that was the impetus,” she says. “If we’re successful, we hope to begin construction in 2024 or 2025. That would be beyond our wildest vision of success.”

But work done with a federal grant will be just a beginning, as it may not include enough money to build the fencing, which is especially challenging in this steep section of highway through the national monument. 

Bowman says in addition to the I-5 project, ODOT is eying the federal grant for a handful of other wildlife crossing projects.

“We really found you have to have these partnerships to get funding,” she says, adding that one way Oregon residents can help is by purchasing a specialty license plate, with proceeds going to help fund wildlife crossings. 

Other western states are also preparing to apply for the federal grants. Last year, the Washington Legislature provided a $2.7 million appropriation that’s set aside to be used as matching funds for the pilot program.

Highway 97 projects       

One hopeful candidate is Safe Passage 97, a coalition in north-central Washington that has been working for 10 years to get a series of crossings along a 12.5-mile stretch of Highway 97 south of Tonasket.

According to Conservation Northwest—one of the coalition members—an estimated 350 deer are hit by vehicles in that stretch of highway each year, making it among the deadliest for wildlife in the state.     

“A whole lot of science through the Washington Connectivity Working Group shows that this 12 miles is one of the main crossing points for 10 focal species,” says Jay Kehne, sagelands heritage program lead for Conservation Northwest.

Kehne says the stretch of two-lane highway has good habitat on both the east and west sides and some of the least developed land, making it important for east-west connectivity.           

Despite unsuccessful attempts until last year to get funding from the state legislature, the coalition raised more than $260,000 in donations and in 2019 renovated a bridge over the Okanogan River as an undercrossing, and used the rest of the private funds to install one mile of fencing.     

“We’ve had a reduction of like 94% or 95% vehicle-deer collisions since that one mile went in,” says Kehne.

He says now that the public sees it working, the rest of the project has more support. But it would be impossible to raise the kind of money needed to complete the project.

“It has to be DOT stepping up to get the extra dollars,” he says.

Moose in Mount Rainier NP likely used crossing    

Conservation Northwest also led efforts to establish safe wildlife crossings along I-90 in Washington, which is now hugely supported by local organizations, government agencies and private citizens.

About half of the full project—which envisions 24 to 25 crossings along a 15-mile stretch of the highway—is complete.

The next major project is another overcrossing near Easton, scheduled for construction in the next couple of years.     

Zylstra, the WSDOT biologist, noted that last summer one of his cameras captured a moose traveling from the North Cascade Range to the south.

Then in December, a moose was documented for the first time at Mount Rainier National Park.      

“It’s highly likely the detected moose is the same moose that showed up in Josh’s videos using one of the I-90 crossing structures,” says Patricia Garvey-Darda, wildlife biologist for the Okanogan-Wenatchee National Forest. “Without crossing structures on I-90, this historic event may not have happened.”

More on the way: This wildlife overpass in Snoqualmie Pass is part of a system of established and planned over- and underpasses along I-90 in Washington. Photo: WSDOT/David Mosley

Garvey-Darda says connectivity is important for genetic exchange and variability, which is critical to the long-term viability of a species and its resilience to changes in the environment.

She’s excited about WSDOT plans for a new wildlife bridge and three large undercrossings that will reconnect populations of mountain goats that have been isolated from each other because of the highway.      

Citizens who follow WSDOT’s Snoqualmie Pass site are also enthusiastic about the crossings. When the video of the cougar crossing was posted, it generated dozens of responses, along with several questions about the kinds and numbers of wildlife using the crossings.

WSDOT spokesperson Summer Derrey, who posts the videos on Twitter, likes to interject a little humor when responding to the public’s posts.       

When one subscriber wrote, “SHOW US BIGFOOT!” she replied, “To the best of our knowledge, Bigfoot only come out when the pass cameras go down.”

Later in the thread, someone else asked if there were any Sasquatch sightings. So Derrey posted a photo of a miniature Bigfoot in a shadowbox.