Seven people remain on the missing list, the sheriff's office said.
A search for bodies continued in the debris left when the March 22 landslide raced across the North Fork of the Stillaguamish River and buried dozens of homes in the riverfront community about 55 miles northeast of Seattle.
Washington Gov. Jay Inslee and other state officials gathered on the steps of the Capitol in Olympia at noon Tuesday to lower the flag. Inslee ordered that flags at all state facilities be lowered to half-staff until the end of the day next Tuesday. April 22 also is the day President Barack Obama plans to survey the damage and meet with victims, first responders and recovery workers.
The slide covered about a mile of state Highway 530, cutting off the direct route between Interstate 5 and the town of Darrington, which is east of the slide and has a population of about 1,300. Reopening the highway is a priority for residents facing long detours.
It could take one to three months to clear all the mud, trees and other debris, state Department of Transportation officials told residents at a Monday night meeting in Darrington.
And it could be fall before damaged roadway is repaired or replaced so the highway could be used, spokesman Lars Erickson said Tuesday.
"We don't know how extensive the damage is," Larson said. "There are a lot of variables; timing could easily change significantly."
In the meantime, residents may be allowed limited use of a temporary access road that has been restricted to emergency vehicles, Larson said.
"We are working to get permission from property owners of that road to find a way to have some kind of limited local access to ease detour strains on communities there," he said.
Community meetings about the highway are scheduled Tuesday evening in Oso and Wednesday evening in Arlington, which is on the west side of the slide.