A large landslide occurred overnight on forestland just east of Oso, Washington, in Snohomish County. The slide, which is visible from Highway 530, affects several acres of state trust land managed by DNR on Wheeler Mountain. The slide appears to have originated on a private holding and then flowed down a steep hillside onto state trust land. No public roadways or privately owned roads are affected, but a DNR-managed road in the area is closed until debris can be cleared.
DNR engineers in the region plan to have heavy equipment and crews at the ready should they be needed over the extended Thanksgiving Day weekend. The National Weather Service predicts another round of heavy rain, winds and mountain snow to hit Thanksgiving Day, on top of the already soaked soils across much of western Washington.
This landslide and others occurring recently will be mapped carefully and entered into a database that DNR maintains. DNR’s Geology and Earth Resources Division combines those data with other landslide research to create hazard maps showing the areas least safe for construction. Learn more on DNR’s Landslide Hazards mapping web page.