MAZAMA, Wash. — State Route 20, also known as the North Cascades Highway, in Whatcom County closed for the winter on Nov. 10, 2021, due to avalanche risk.
SR 20 is closed to traffic between milepost 134/Ross Dam Trailhead and milepost 171/Silver Star Gate.
The highway was originally expected to close Nov. 15, but at the time the Washington State Department of Transportation (WSDOT) said the closure could happen earlier depending on snow, ice and winter conditions.
SR 20 is the northernmost route across the Cascade Mountain Range in Washington. It's also part of the Cascade Loop, which is a 400-mile driving tour through the Cascades, according to WSDOT.
The WSDOT said the seasonal closure date has been assessed on a case-by-case basis in the past, but a closure date was set this year to allow travelers to plan ahead.
The highway usually closes between late November and mid-December due to avalanches.
Hikers, skiers, snowmobilers and other winter recreationists can access the closed portion of the highway during the winter season by parking in designated areas and allowing plow drivers to clear the snow.
WSDOT recommends checking the forecast and road conditions before you go, as conditions can change quickly in the mountains.
The stretch of highway closed last year on Nov. 16. SR 20 usually reopens in the spring by early May.