DARRINGTON, Wash. -- Families coping with the loss of friends, neighbours and normalcy sought comfort in church services Sunday, as crews worked to recover more victims from the soggy pile of mud that buried the small mountainside community of Oso in Washington state, more than a week ago.

Late Saturday, authorities said the number of people believed missing decreased substantially, from 90 to 30. The official death toll of victims identified by the medical examiner increased by one, to 18, said Jason Biermann, program manager at the Snohomish County Department of Emergency Management.

Rescue crews said Sunday that many of the dogs that have been essential in the search for victims will take a two-day break. Days of sniffing through cold, soupy mud and nearly nonstop rain have taken their toll on the animals, and officials say dogs can lose their sensing ability if they work too long.

"The conditions on the slide field are difficult, so this is just a time to take care of the dogs," said Kris Rietmann, lead spokeswoman for the team working on the eastern portion of the slide.

Dogs from the Federal Emergency Management Agency, more recent arrivals on the scene, will continue working, said Heidi Amrine, another spokeswoman for the operation.

Engineers were watching for any material sloughing off the landslide area, making sure that a weekend of torrential rainfall doesn't displace more land.

Meanwhile, many residents attended church services for solace ahead of another week of recovery efforts.

"I can only compare it to a hot hearty meal after a very cold day," Slava Botamanenko of Darrington said of the church services.

Botamanenko works at the hospital in Arlington and said he spent two nights there to be sure he was available for work after the slide shut the road.

Authorities have said they have recovered more than two dozen bodies, but they won't be added to the official tally until a formal identification is made. And, underscoring the difficulty of identifying those killed in one of the deadliest landslides in U.S. history, Biermann said crews are not always discovering complete remains.

This weekend, crews completed a makeshift road that will link one side of the debris field to the other, significantly easing the recovery operation. They've also been working to clear mud and debris from the highway, leaving piles of gooey muck, splintered wood and housing insulation on the sides of the road.

Searchers have had to contend with treacherous conditions.

The search area has septic tanks, gasoline, propane tanks and other hazards. When rescuers and search dogs leave, they're hosed off by hazardous materials crews stationed at the edges of the debris field.

The slide dammed up the North Fork of the Stillaguamish River, causing water to pool up on the east side. The river cut a new channel through the mud, but torrential weekend rainfall has raised the water level nearly 30 centimetres, Rietmann said Sunday.

In at least one place, the water level has risen so high that it's covered areas that have already been searched by Snohomish County responders, said Tim Pierce, leader of Washington Task Force 1, a search and rescue team.

"At this point there's no point in searching (that area) again until the water drops back down," Pierce said.

Rescuers should get some relief soon. Mainly dry weather is forecast Monday through Wednesday in Western Washington.

The size of the debris field is also smaller than initially thought, officials said Sunday. After further scientific review and analysis, geologists have determined that the size of the debris field is about 120 hectares in size. That's just under half the size of the earlier projected 2.6 square kilometres.

Away from the whirring chain saws and roaring bulldozers, many residents of the nearby community of Darrington sought quiet comfort in church services.

All week, a steady stream of people has stopped in to pray at the Glad Tidings Assembly of God on the edge of town, Senior Pastor Les Hagen said.

"At a time like this, everybody knows they've got to have God's help," Hagen said.

Baumann reported from Seattle.