TWISP – With heavy snow in the forecast, the North Cascades Highway (State Route 20) will temporarily close tomorrow and may not reopen until next spring.
At 9 a.m. Friday, Nov. 18, the Washington State Department of Transportation will close a stretch of the scenic highway between the Diablo gate on the west side (milepost 134) and the Silver Star gate on the east side (milepost 171) due to the high potential for more avalanches this weekend.
The area has seen several stout shots of winter weather and some avalanche zones have already released, filling the roadside catchment basins. Any additional slides will hit the highway.
Drivers crossing Washington Pass this morning were greeted with more new snow on the pavement and a 3-foot accumulation on the shoulders.
Early next week, WSDOT will assess road conditions, avalanche danger and weather forecasts to determine if Thanksgiving travel on SR 20 is possible.
If the highway closes for the season, it would be on par with last year, when the road began its annual hibernation on Nov. 16.
The 37-mile winter closure zone begins seven miles east of Diablo Dam at milepost 134 on the west side of Rainy Pass (elevation 4,855 feet) to nine miles west of Mazama at milepost 171 below Washington Pass (elevation 5,477 feet).
Visitors planning a trip via the North Cascades Highway should check current conditions before they hit the road using WSDOT’s online travel tools.