Eastern portion of North Cascades Highway to reopen April 30; western section remains closed for major repairs

SR 20 to remain closed between Diablo Lake and Porcupine Creek

NEWHALEM - State Route 20/North Cascades Highway will partially reopen from the east side beginning at 2 p.m. Thursday, April 30.

Travelers will be able to access a portion of the highway from the east to milepost 156.8 at Porcupine Creek. The road will remain closed in both directions to vehicles and recreation between Porcupine Creek and milepost 130 near Diablo Lake on the west side. This will allow contractor crews working for the Washington State Department of Transportation to prepare for and begin extensive repairs following significant winter storm damage and a spring rockslide.

"This isn't just clearing debris," said WSDOT Assistant Region Administrator Melissa Ambler. "In many places, we have to rebuild the roadway from the ground up."

Damage spans multiple miles and goes well beyond what's visible from the surface, according to Ambler, who heads the agency's Mount Baker Area. In several locations, heavy runoff overwhelmed culverts and drainage systems, sending water over and beneath the roadway. That water washed away the material supporting the highway, leaving sections of pavement undermined. In some places, the road is no longer fully supported underneath.

WSDOT identified several locations where repairs need to be made before the road can fully reopen. Work to begin clearing the rockslide near Diablo Lake is expected to begin as soon as the week of May 4 and will be completed under a 30-day emergency contract.

While WSDOT has made repairs quickly to other highway emergencies this season, this situation is different. The additional work on SR 20 between mileposts 142-148 cannot be completed under the time constraint of an emergency contract, even working around the clock, due to the extent of the damage and the complexity of the repairs.

There are also multiple locations where:

• Embankments that support the roadway have been washed out and need to be rebuilt.
• Culverts are damaged or blocked and must be repaired or replaced.
• Drainage systems and ditch lines need to be reconstructed.
• Slopes above the highway remain unstable and require rock removal and stabilization.

WSDOT recently brought prospective contractors to the sites to assess the full scope of work and prepare bids. Once a contract is awarded, repairs are expected to take several weeks, with crews working up to seven days a week where possible.

This work will go beyond clearing debris. Crews will:

• Rebuild sections of roadway where the ground beneath the pavement washed away.
• Repair and replace culverts and drainage systems.
• Stabilize slopes above the highway.
• Restore guardrail and roadway infrastructure.

The precise timeline will depend on field conditions and the complexity of the work as it progresses. In some areas, repairs may require crews and engineers to adjust plans in real time as they uncover additional damage.

A more defined schedule will be available once a contractor is selected and construction begins.

The closed section of SR 20 will remain an active work zone during this time. There is no safe way to allow public access through the area, including hiking, biking or camping. While some damage is visible, much of it is not, including areas where the roadway is undermined beneath the surface and slopes above remain unstable.

"We're moving this work forward as quickly as we can," Ambler said. "Our goal is to reopen the highway safely and keep people informed on the progress we are making."