State Route 20 is the northernmost route across the Cascade Mountain Range in Washington and is commonly referred to as the North Cascades Highway. This Scenic Byway offers travelers a wide array of beautiful vistas and is part of the Cascade Loop, a 400-mile driving tour through the Cascades. Take a virtual drive on the highway from your computer.
Pass status: Open
UPDATE: Monday, Sept. 22 - East of the North Cascades, SR 20 is open between Twisp and Okanogan over Loup Loup summit, where it was closed Aug. 21 by heavy flooding. However, now drivers should expect delays at milepost 208, about halfway between Twisp and Loup Loup. Traffic is reduced to one lane, with a pilot car guiding vehicles around a half-mile of washed out highway lane. Rebuilding the second lane is expected to take a few more weeks. Off-road repairs will continue for another month or more. Five miles of SR 153 between Twisp and Carlton remains closed due to three washouts. An easy 13-mile detour is available via the Twisp-Carlton Road.
Why we close the highway in winter:
We close the North Cascades when weather, snow conditions and avalanche danger threaten the safety of drivers and our maintenance crews. We close the highway on the west side at milepost 134, east of Diablo, and on the east side at milepost 171, 14 miles west of Mazama. As the snow gets too deep for the plow truck, the east closure point is moved 7 miles down to the Early Winters Information Center at milepost 178. Avalanches typically close the highway between late November and mid December.
Reopening in the spring is usually accomplished by early May.
Current driving conditions:
Between April and November when the road is typically open, we post the current North Cascades Pass report on our WSDOT mountain passes Web page as we do for all of the passes. May through October, pass conditions are only posted if there's a potential travel hazard.
Current weather conditions:
For recreation purposes and while the highway is closed, or in the summer when the pass reports are suspended, you can find weather information with these links:
Contacts for more information
Jeff Adamson, Communications
North Central Region-Wenatchee
Tom Pearce, Communications
Sign up for: E-mail updates for the North Cascades Highway