To a beaver, a culvert providing fish passage under a forest road looks like a hole in a dam in need of fixing.

Over the years, beavers in the Mount Baker-Snoqualmie National Forest had filled a 17-foot-wide pipe, flooding a road along the Suiattle River. The U.S. Forest Service asked area tribes for help.

The Stillaguamish Tribe has been working with Snohomish County and private landowners to build “beaver deceivers” to prevent the industrious animals from clogging culverts.

“We have a beaver translocation program, but we’re trying to keep as many beavers in place as possible,” said Jennifer Sevigny, wildlife biologist for the Stillaguamish Tribe.

Tribal staff clear a beaver dam from a culvert

Tribal staff clear a beaver dam from a culvert near the Suiattle River.

“We were fortunate the Stillaguamish Tribe had the supplies and equipment on hand and had staff that could train some of our natural resources staff in removing the dam from the culvert and building the deceiver,” said Emily Wirtz, wildlife biologist for Sauk-Suiattle. “Now, we will be ready for any potential future beaver disturbance in the Darrington area.”

When they aren’t flooding roads or property, beaver dams, lodges and underwater passages provide reservoirs of cool water that benefit other wildlife, plants and fish.

In June, natural resources staff from the Stillaguamish and Sauk-Suiattle tribes cleared the culvert of branches and sediment before installing fencing around the opening. Beavers will be able to build new dams around the fencing, while being deceived by underwater pipes that maintain the water level and flow.

“I really feel overwhelmed with the support of the tribes in meeting common goals of retaining beaver on the landscape, providing for fish habitat, protecting the road and providing resources,” said Phyllis Reed, wildlife biologist for Mount Baker-Snoqualmie National Forest. “A big salute to the ingenuity, efficiency and hard work of the Stillaguamish and Sauk-Suiattle crew, as well as the gracious support in resources and materials.”

View more photos of the beaver deceiver installation on Northwest Treaty Tribes’ Flickr page.

Click to learn more about beaver relocation programs.