I-90 Wildlife Corridor Campaign

Since 2000, through The Cascades Conservation Partnership and the I-90 Wildlife Bridges Coalition, we’ve led efforts to reconnect Washington’s north and south Cascades by protecting and restoring habitat and establishing safe wildlife crossings under and over I-90.

These two coalitions represent only part of Conservation Northwest’s involvement in this area, which is organized internally under our I-90 Wildlife Corridor Campaign. This larger campaign includes our role administering coalitions and other projects including I-90 Wildlife Watch, as well as on-the-ground habitat restoration around the new wildlife crossings through volunteer, staff and contract revegetation work, and wildlife monitoring and snowtracking through our Citizen Wildlife Monitoring Project to document wildlife movement in this corridor.

On many fronts, we’re working to protect, connect and restore habitat in the I-90 corridor!

Learn about Cascade Crossroads, a documentary film we produced in 2018 to share the collaborative success story behind the I-90 wildlife crossings. Or watch WSDOT’s latest video (published in November 2021) about ongoing work!

Or watch this short film on our work for wildlife crossings:



I-90 Wildlife Corridor Campaign News

• November 2021: I-90 Snoqualmie Pass East: Critter Crossings in the Cascades, WSDOT Video
• September 2021: I-90 Wildlife Watch program sunsets after more than a decade collecting motorist reports of animals on the interstate near Snoqualmie Pass
• June 2021: Fisher photographed on trail camera near I-90 Wildlife Crossings
• June 2021: Video: I-90 wildlife crossing cameras capture big uptick in animal use near Snoqualmie Pass, The Spokesman Review
• April 2019: How wildlife bridges over highways make animals—and people—safer, National Geographic
• December 2018: New Animal Overpass Is Already Protecting Critters in Washington State, Smithsonian
• December 2018: Washington state builds bridge to keep wildlife off highway, Associated Press
• October 2018: Restoring habitat in the I-90 Wildlife Corridor
• September 2018: Critters are already using unfinished animals-only bridge over I-90, KUOW Radio
• September 2018: ‘It’s a long time coming’: $6.2 million wildlife bridge over I-90 nears completion, The Seattle Times
• September 2018: Bridge over I-90 offers safe passage for wildlife, Crosscut
• August 2018: I-90 Wildlife Watch: A Year in Review
• May 2018: Elk using I-90 wildlife crossings this spring
• February 2018: Your support creates safe passage for people and animals
• January 2018: Cascade Crossroads film documents story behind I-90 wildlife crossings

I-90 Wildlife Bridges

Conservation Northwest has been a leader in getting wildlife connectivity included in the I-90 Snoqualmie Pass East Project. 

Through our I-90 Wildlife Corridor Campaign and the I-90 Wildlife Bridges Coalition (of which we are the administering organization and fiscal sponsor), and by working with the Washington Department of Transportation (WSDOT), elected officials and our community allies, we’re focusing on making a critical 15-mile stretch of freeway safer for both people and wildlife.

Four large wildlife undercrossings are already completed and in use by animals big and small. Four more crossings are currently under construction, including the first of two planned wildlife overcrossings or “bridges”. Culverts are also being expanded for fish passage and smaller wildlife species.

A huge thank you to WSDOT, the U.S. Forest Service, Forterra and our other coalition partners who’ve supported this effort, including Sierra Club, The Nature Conservancy, Mountains to Sound Greenway Trust, American Rivers, The Summit at Snoqualmie, and many other organizations, business, elected and community leaders!

Wildlife undercrossings

Undercrossings include creek crossings, wildlife-size culverts, and three major wildlife underpasses or stretches of raised highway up to 900 feet long. The following undercrossings are now complete:

• Two undercrossings at Gold Creek east of Snoqualmie Summit at the northwest end of Lack Keechelus. Because Gold Creek Valley “funnels” traveling wildlife north-south, connecting with the east-west landscape of Snoqualmie Pass and Cold Creek valley to the south, it’s a natural migration route and important area for many species in the Cascades including elk, deer, bull trout, kokanee salmon and hopefully soon wolves and wolverines. 
• One undercrossing at Rocky Run Creek, to the east of Gold Creek, providing better aquatic connections for spawning bull trout and safe passage for wildlife between Lake Keechelus and thick forest to the north.
• One undercrossing at Resort Creek east of Rocky Run, providing similar benefits for both fish and wildlife.

Overcrossings or wildlife “bridges”

Two fully vegetated, 150-foot-wide overpasses are planned. Construction on the Keechelus Wildlife Overcrossing (formerly called the Price-Noble Wildlife Overcrossing) began in Spring 2015. In the fall of 2018, construction was completed, becoming Washington’s first-ever wildlife bridge over a highway or freeway, and the largest wildlife overcrossing in North America. 

Check out these photos of our staff members working with WSDOT to install remote cameras on the overpass, shortly after its completion! These cameras have already documented wildlife using the overpass to safely cross the highway.

A second wildlife overpass near Easton is planned and fully funded. Construction will begin in coming years.

Restoring the Habitat

The tens of thousands of acres that we protected in The Cascades Conservation Partnership were previously managed for intense timber harvest that included homogenous tree plantations and excessive and poorly maintained spur roads.

Through our campaign, we donated these lands to the U.S. Forest Service, adding to their already large restoration needs in the I-90 corridor. Therefore, we now aim to use the same energy that we brought to protecting lands in this critical location to restoring habitat for the watershed and wildlife.

Our Central Cascades Watersheds Restoration program is hard at work to restore the habitat within the corridor including on the lands protected during the Partnership by thinning forests to promote stand diversity and increase tree growth, while reducing unnecessary road miles fragmenting habitat and decreasing watershed health.

Finally, we are engaging volunteers to directly help improve habitat in the Gold Creek area near two of the new wildlife underpasses by removing invasive plants and planting native vegetation in partnership with both the Mount Baker-Snoqualmie and Okanogan-Wenatchee National Forests. Hundreds of volunteers have donated nearly 1000 hours each year to weed, mulch, and plant well over 10,000 plants to date, improving habitat for fish and wildlife and making the wildlife undercrossings more appealing.

Sign up for a habitat restoration work party today!

Monitoring Wildlife

One of the best motivations to keep up our work in the I-90 corridor and to measure our success is the wildlife moving through the area.

We support and engage with official agencies and other research efforts in the I-90 corridor and lend our volunteer capacity to further that work. We also work with partners and scientific advisers to organize the power of citizen science to bring a face to this landscape through our Citizen Wildlife Monitoring Project.

We also lead I-90 Wildlife Watch, a program that was launched to encourage the 27,000 motorists that drive I-90 through the corridor each day to report live or dead wildlife they see from their cars. 

These monitoring efforts are important for better understanding the movement of wildlife through the I-90 corridor and the Central Cascades, as well as the effectiveness of our efforts to protect, connect and restore habitat in the Snoqualmie Pass area.

The landscape in Washington’s Central Cascades, spanning Snoqualmie Pass and bisected by I-90, forms an important travel corridor for people, goods and wildlife.

Want to be a part of this important effort? Make a donation or become a member today.