OSO, Washington (CNN) -- Still struggling to find possible bodies buried in mud, rescue crews will hold a moment of silence Saturday at the exact hour one week ago when a landslide struck rural Washington state, killing 17 people.

The momentary vigil is part of a statewide observance scheduled for 10:37 a.m. PT, the appointed hour on March 22 when a hillside mass collapsed 60 miles northeast of Seattle and obliterated homes, trees and anything else in its path for hundreds of acres in a Stillaguamish Valley community called Oso.

Gov. Jay Inslee announced Friday that a silent pause will be held. "I know that every Washingtonian holds in their heart the people of the Stillaguamish Valley and we all wish we could ease their pain," he said in a statement.

At Darrington, about 15 miles from Oso, residents and officials will hold a town gathering outside the bay doors of the firehouse and will conduct the momentary silence.

A forecast of continuing rain Saturday is expected to compound the slow movements of rescue workers, who are laboring in chest-high mud and must negotiate propone tanks, septic tanks and other debris in the disaster zone.

"Morning everyone," Snohomish County officials posted on their Twitter page. "We're expecting heavy rain this morning near ... slide site. Could be challenging for ground teams, air operations."

Snohomish County Executive Director Gary Haakenson said Friday evening that the official death toll is 17, which is the same number as had been given earlier in the day. Officials had earlier indicated they would announced a new figure on Friday, but that announcement was never made as the county medical examiner's office continued processing its findings.

Officials also said late Friday the number of missing and unaccounted for is 90, just as it has been for several days.

"It's a very, very slow process," Haakenson said late Friday. "It was miserable to begin with, and ... it's rained heavily in the past few days. It's made the quicksand even worse."

Friday's downpours added to rain that fell the previous two days, with more such precipitation likely through the weekend and beyond, according to the National Weather Service's forecast.

Ironically, the rainfall comes as waters started to recede in the area following last Saturday's landslide near Oso, with flooding from the Stillaguamish River. Areas that dried are now saturated again.

In response, local officials brought in more geologists to ensure active monitoring of another potential landslide that could put hundreds of rescue workers into harm's way.

Steve Mason, a Snohomish County fire battalion chief, explained "everything is gray, so anybody you're going to find in there, anything of any importance that you're going to find in there looks gray. So you have to really focus."

Given the potential that a person -- dead or alive -- might be hidden in the morass, crews tried to be meticulous in their work.

"Most of it is just digging in the mud and trying to find closure for people," volunteer searcher Gordon Storoe said. "Literally, a handful of dirt at a time."

The more rain, the harder it is to sift through that dirt, not to mention move through it.

Snohomish County Executive John Lovick noted that some workers were taken out of one area due "some sloughing" before geologists surveyed the situation and determined it was safe to go back.

Workers have made big progress in creating an east-west roadway to connect searchers on both sides of the landslide.

Still, in between, "the digging is very tough," Mason noted.