The Washington State Department of Transportation issued this news release on the winter closure of SR20/North Cascades Highway
DIABLO – The final page will soon turn on State Route 20/North Cascades Highway this year. The winter gates will close at 4 p.m. Friday, Nov. 10 due to avalanche risk, and there will be one less route for vehicles crossing the Cascade Mountains.
Washington State Department of Transportation crews have plowed SR 20 between the gates at mileposts 134 near Diablo and 171 west of Mazama since snow began falling in early October. But, new snow has continued to fill avalanche chutes. The forecast for more this weekend makes it too dangerous for our crews to work or the public to drive below full avalanche zones.
“We know this route is popular for access to businesses, relatives and outdoor adventures said WSDOT Twisp Maintenance Supervisor Don Becker. “Our crews work hard to keep it open through the Thanksgiving weekend, but this year it isn’t possible due to the amount of snow in the forecast.”
The highway temporarily closed twice in the last three weeks due to snow accumulation in avalanche chutes.
This year’s closure is a week or so earlier than typical. Last year, the North Cascades Highway closed on November 18. The only time the highway remained open through the winter was in 1976, when a drought produced record-low snowfall.
Winter access along the highway
Snowmobilers, hikers, skiers and other winter adventurers are free to use the roadway behind the gates, but they do so at their own risk.
Starting the 2018 chapter
When conditions permit, crews will reopen the highway in spring 2018. Clearing the 37-mile-long mountain pass highway requires crews working from both sides for roughly four to six weeks.