Blewett Pass on Highway 97, which stretches between Leavenworth, Chelan County, and Ellensburg, Kittitas County, is closed for the nearby Labor Mountain fire.
Crews from the Washington State Department of Transportation closed the pass overnight Sunday and will reassess conditions Monday, WSDOT East said in a post online. The road is closed from milepost 178 to 149.
The Labor Mountain Fire is burning nearby at over 7,600 acres. The fire was started by lightning on Sept. 1, according to the Northwest Interagency Coordination Center.
Authorities have ordered some residents along Blewett Pass to evacuate.
Drivers should take Interstate 90 or Highway 2 as alternate routes, WSDOT said.
But Vantage Bridge on I-90 is reduced to a single lane in both directions, the agency warned. Drivers sho