Highway 530 reopens after days-long closure due to slide concerns

OSO – Highway 530 near Oso reopened this afternoon following an emergency closure due to an unstable slope above the highway.

This past weekend, crews installed 11 monitoring locations to track ground movement and analyzed the hillside twice a day. After several days of no measurable movement, geologists have decided to reopen the highway.

Snohomish County officials have also lifted the voluntary evacuations for residents. WSDOT assistant regional administrator Dave McCormick said, “We know this is a vital path for many folks and appreciate your understanding as we worked to keep residents safe and track any movement of this twenty—four-acre slide.”

“The highway could close again if crews detect significant ground movement,” McCormick said. On April 3, WSDOT crews were notified about ground movement near Montague Creek along the south side of Highway 530.

On April 7, DNR crews observed additional ground movement. Heavy rains over winter and spring most likely contributed to the movement. Highway 530 was closed between Oso Loop Road (milepost 34) and C-Post Road (MP 38). The detour required travelers to use Highway 20, which added at least an hour to a one-way trip.e slide is approximately 1.5 miles southwest of the 2014 landslide that killed 43 people.