Contractor crews are stabilizing the slope above State Highway 20 and are on track to fully reopen the road (also known as the North Cascades Highway) near Rockport early in August, the Washington State Department of Transportation said in a press release last week.
A portion of the highway between Marblemount and Rockport has been closed since a large rockslide on June 10. A 14-mile detour takes motorists around the slide area by way of State Highway 530, Rockport Cascade Road and Cascade River Road.
WSDOT said the construction crews will spend the next two weeks drilling into the hillside to insert rock dowels. The long metal rods will reinforce the hillside to prevent future rockfall, WSDOT said. Grout will anchor the rods and metal plates will be attached to hold the large rocks in place.
Once the hillside is stabilized, crews will remove the remaining fallen rocks and debris and reopen the closed portion of the highway, WSDOT said.
The initial rock slide dumped about 150 cubic yards of debris onto both lanes of the highway at milepost 98. By the following morning, more rocks had fallen, piling up to 1,000 cubic yards of debris, enough to fill about 70 dump trucks, WSDOT said.
Funding for the project comes from Washington state’s preservation funds and is expected to cost around $700,000.