A snowy forecast means State Route 20 North Cascades Highway will close for the season at 6 a.m. on Wednesday, Dec. 11. This is the latest road closure date in more than a decade.
Washington State Department of Transportation crews close this stretch of SR 20 every year once snow fills the avalanche chutes that line the highway, which poses a safety risk to travelers and road crews.
The closure points are at milepost 134/Ross Dam Trailhead and at milepost 171/Silver Star Gate. When significant snow begins to fall, WSDOT crews will move the western closure point back to milepost 130/Colonial Creek Campground and the eastern closure point to milepost 177/Early Winters Campground. These weather-dependent changes usually happen in January. Signs along SR 20 are posted in advance of the closure point and updates on the WSDOT website will reflect where the road is closed.
Hikers, skiers, snowmobilers and other recreationalists can access the closed portion of highway during the winter season. Users should park in designated parking areas to allow plow drivers the space they need to clear snow around the closed stretch’s access gates.
WSDOT closes this stretch of highway due to avalanche risk, so anyone using this area should check forecasts and be aware of quickly changing conditions in the mountains. Travelers can also check conditions with North Cascades National Park before trips to this area.
In late winter/spring 2020, WSDOT avalanche and maintenance crews, including Mazama the Avalanche Rescue Goat, will assess conditions and begin clearing work to reopen this cross-state route through the Cascade Mountains.