Elk find safe passage under I-90 thanks to wildlife crossings

ConservationNWAdmin / Feb 16, 2018 / Connecting Habitat, I-90 Wildlife, Wildlife Crossings

Note: This blog originally appeared on our I-90 Wildlife Watch project webpage. An effort to document wildlife movement around Snoqualmie Pass between North Bend and Easton, I-90 Wildlife Watch is led by Conservation Northwest with support from Central Washington University, the Washington State Department of Transportation, the Washington Department of Fish and Wildlife, the U.S. Fish and Wildlife Service, and the U.S. Forest Service.

By Jen Watkins, Conservation Associate and I-90 Wildlife Bridges Coalition Coordinator

Fall is a time when wildlife are on the move in the Cascades, from elk and mule deer making seasonal migrations to black bears looking for a meal before hibernation. This extra animal activity makes checking the remote cameras operated by the Washington State Department of Transportation (WSDOT), Washington Department of Fish and Wildlife, Conservation Northwest, U.S. Forest Service and other I-90 Wildlife Watch project partners particularly exciting this time of year!

Along with reports from motorists, snowtracking and roadkill data, these motion-activated cameras document animal movement in the I-90 corridor and have informed wildlife crossing projects and habitat conservation between North Bend and Easton.

Recently, a WSDOT biologist sorting through the thousands of images from cameras at the recently-completed wildlife underpasses at Hyak and Gold Creek found amazing images of some of the first elk using these structures.

Elk are an iconic North American ungulate species that are highly valued culturally, socially, and ecologically. Though not as numerous as in the Rocky Mountains, elk are fairly common in the Cascades today. Their large size and tendency to travel in herds makes them one of the more noticeable species spotted by motorists and recreationists in the I-90 corridor. Elk travel seasonally, typically roaming between summer ranges in the high and mid-elevation forests and meadows of the Cascades and winter range in either the sage-steppe foothills to the east of the mountains or the farmlands, forests and river valleys to the west.

The six lanes of Interstate 90 can present a dangerous barrier to elk on the move—and people, too. Reaching weights well over 500 pounds and standing more than four feet at the shoulder, elk crossing the busy interstate were a primary concern highlighting the need for safer passage on Interstate 90 for both motorists and wildlife through the construction of wildlife crossings.

“We have known that elk were in the area on both sides of the interstate, and we know that they are more active in the project area in fall for sure” said Josh Zylstra, wildlife biologist with WSDOT. “The state of the science tells us that elk typically don’t like things over their head, and therefore they tend to be more cautious about utilizing structures that cross under the roadway.”

While data from other states and provinces shows that elk prefer more open wildlife “bridges”, Zylstra’s images revealed that elk were not only utilizing both wildlife crossing structures at Hyak and Gold Creek in October 2017, but weren’t in a hurry to pass under the interstate as traffic moved above. The images and videos from the remote cameras capture elk browsing on grasses and shrubs growing in the underpass, and taking their time moving through.

Upon reviewing the images Josh observed, “Seeing them underneath the Gold Creek bridge utilizing the structure was great, but it was especially exciting to see them utilize the smaller structure just to the west of the Gold Creek bridges (near Hyak) that is accessible for them all-year round even when the waters flood the Gold Creek bridge.”

“Additionally, the really cool thing in reviewing the remote camera footage was seeing their comfort level. They didn’t appear to be spooked by anything overhead. In fact, photos recorded several elk bedding down for over two hours within the Gold Creek underpass. It seems like it’s doing a good job of mimicking a natural environment.”

While these photos are exciting, what they mean for the future is even more inspiring.Elk mothers are known to teach their calves favored migration routes. Now that they’ve begun to utilize the wildlife crossings, it’s expected we’ll see more elk making safe passage under I-90 while anticipation builds for how they’ll respond to the first wildlife overpass set to be complete next year. Stay tuned for more updates!

Visit our Flickr photo gallery to see more images of elk using the I-90 wildlife crossings.