I-90 Wildlife Bridges Coalition

Building connectivity for wildlife in the Cascades

Connecting habitat in the Cascades means making sure that large mammals can roam more freely north to south within Washington. The I-90 Project will make a critical 15-mile stretch of interstate along a busy passage between Snoqualmie Pass and Easton in the Cascades safer for people and wildlife. It features the first-ever freeway wildlife passage in Washington, featuring underpasses that will give wildlife and waterways an uninterrupted pathway. These underpasses allow terrestrial and aquatic mammals to safely travel across the interstate, which will be imperitive to keeping their ecosystems going and preventing traffic collisions. 

This plan to improve connectivity is the natural outcome of another historic project, The Cascades Conservation Partnership.

Administered by Conservation Northwest, the I-90 Wildlife Bridges Coalition was formed to make sure the freeway upgrade incorporates over- and underpasses and bridges for wildlife, which will open up a considerable space for travel. 

The I-90 Snoqualmie Pass East Project is designed to improve 14 key animal-travel areas on Interstate 90 between Hyak and Easton, an area busy with traffic and much frequented by wildlife. Improvements to the freeway ranges from avalanche control on key sections to diverting wildlife over and under the freeway through carefully designed passages.  Passages beneath the freeway include creek crossings, wildlife-size culverts, and over the interstate, two overpasses, one at Easton Hill and the other at the rock knob by the Keechelus Dam. These 150-foot-wide wildlife bridges span the length of the interstate. The bridges will be fully vegetated on top so the animals feel protected by forest cover as they cross.

 In 2008, the Washington State Legislature funded nearly all of Phase 1 of the project, and the Department of Transportation held a groundbreaking on first construction in August 2009. Still unfunded are 1.5 critical miles, including the Rock Knob wildlife bridge.

There are many endorsements for this project. Learn more at the Department of Transportation site.

I-90 Wildlife Bridges Coalition steering committee

• Alpine Lakes Protection Society 
• Biodiversity Northwest 
• Conservation Northwest 
• Kittitas Audubon Society 
• Seattle Audubon Society
  
• Sierra Club 
• The Cascades Conservation Partnership

Endorsing organizations

• American Rivers
• Center for Tribal Water Advocacy
• Defenders of Wildlife
• Humane Society of the United States
• The Nature Conservancy of Washington
• Washington Environmental Council