Highway 20, the northernmost pass across the North Cascades, closed for the winter season at 6 p.m. Thursday.
Also called the North Cascades Highway or State Route 20, the scenic road connecting Whatcom and Skagit counties to the Methow Valley typically closes because of avalanche danger after the first significant snowfall of winter, according to the Washington State Department of Transportation.
A pair of late-week storms are expected to drop 2 feet or more of snow across the North Cascades, according to the National Weather Service.
Heavy rain was expected to start Saturday and last until at least Tuesday.
“The potential for up to 20 inches of snow beginning Thursday, followed by continued precipitation through the weekend and next week, has increased avalanche risk over Rainy and Washington passes. Travelers and recreationalists always should prepare for changing highway conditions when traveling into the mountains,” WSDOT said in an emailed statement.
The closure point is milepost 134, east of the mountain village of Newhalem at the Ross Dam Trailhead, WSDOT said.
Highway 20 usually opens in May, allowing Whatcom County residents easier access to warmer spring weather in Eastern Washington.