The American Alpine Institute's blog reports that the North Cascades highway is closed for the season:

The gates are closed until spring on the North Cascades Highway. SR 20 was closed temporarily at 8 p.m. Tuesday, Nov. 15, in advance of heavy snow storms. When conditions and forecasts were reassessed early Monday morning, Nov. 21, maintenance and avalanche teams determined it wasn’t safe to attempt reopening the highway for Thanksgiving.