It’s the northernmost highway that crosses the Cascades Mountains in Washington. Because of avalanche danger from the high slopes of Washington Pass and Rainy Pass, the highway is closed in late fall near Diablo on the west side and Mazama on the east side.

The Washington State Department of Transportation is reminding travelers to stay alert and plan for weather conditions.

Highway 20 between milepost 134 at Ross Dam Trailhead and milepost 171 at the Silver Star Gate had closed for the season in mid-November.

The North Cascades Highway reopened to the public on Earth Day, April 22, offering drivers access through one of Washington’s most scenic routes.

The Washington State Department of Transportation has reopened State Highway 20, also known as the North Cascades Highway, for the 2025 season.