PORTLAND, ORE. >> Residents in the foothills of the towering Blue Mountains in rural northeast Oregon were plucked from their flooded homes by helicopter and others rode to safety in the bucket of a front-end loader as relentless rain and melting snow pushed multiple rivers over their banks.

An earlier heavy snowfall in the mountains combined with two days of steady rain and warming temperatures to unleash floodwaters on the city of Pendleton and rural, mountain foothill communities to its east late Thursday and Friday. The Umatilla River crested just before 10 p.m. Thursday at more than 19 feet (5.79 meters), nearly four times the average height for that date. Rivers all around the region overran their banks, setting records as they went.

Oregon Gov. Kate Brown declared a state of emergency in Umatilla, Wallowa and Union counties late Friday to help communities deal with the severe flooding. The declaration means Oregon can mobilize the National Guard if needed.

Authorities were still conducting search and rescue operations Friday with two helicopters, trying to reach residents still boxed in by high water in rural communities like Gibbon and Bingham Springs. They also described a chaotic scene from late Thursday, when rescue personal had to improvise to get the last few residents out of a rapidly flooding area of Pendleton using heavy machinery usually used for road maintenance.

“The last few residents that we evacuated, we used a front-end loader and put them in the bucket. The current was pretty heavy, and there were a lot of obstructions underwater,” Pendleton Police Chief Stuart Roberts said. “It was difficult to navigate.”

A breach in the levee sent water into several large manufacturing plants and the wastewater treatment plant, Roberts said. Residents on wells were advised to boil their water.

Authorities in Umatilla County had used 35,000 sandbags by Friday and another 50,000 were en route from Portland, Oregon, about 210 miles (337 kilometers) to the west.

Evacuation shelters were open in Pendleton and on the Confederated Tribes of the Umatilla Indian Reservation, which was also hit hard by the flooding.

All but a nine-mile (14-kilometer) stretch of I-84 was once more open Friday after much more extensive closures earlier in the day. About a five-mile (8-kilometer) stretch of the freeway — which links Idaho and Oregon — will be closed for up to a week because of damage from the flooding, said Tom Strandberg, a spokesman for the Oregon Department of Transportation.

“There’s now a river running between the median, so it’s interesting — but at least the freeway is open now except for that detour,” he said Friday in a phone interview.

Resident Chantel Fuller told the East Oregonian that she watched the water rise Thursday until it filled her home in a matter of hours. Her neighbors’ home in rural Thorn Hollow was underwater, and other neighbors were stranded, she said.

“Our neighbors are stuck in their house and my husband and a friend went to go help them out and now they’re stuck on the roof. I’ve never seen it like this,” she said in a video clip posted on the newspaper’s website. “It flooded good last year — which is the highest I’ve seen it — and this year tops (that).”

The four were rescued. But the rescuers themselves had to spend the night there because of a fuel issue with the helicopter and were pulled out on Friday, Umatilla County Sheriff Terry Rowan said. The Oregonian/OregonLive reported 10 total rescues, but Rowan could not confirm that number.

Elsewhere in the Pacific Northwest, officials braced for more flooding and landslides from relentless rains.

King County in western Washington announced on Friday night that the Green River had reached flood stage. The county told people living near the river to take precautions.

Washington Gov. Jay Inslee issued an updated emergency proclamation for 20 counties because of damage from storms that are forecast to continue into the weekend. King County Executive Dow Constantine signed an emergency declaration Thursday to speed up response. A small number of National Guard troops were assisting residents near hard-hit Carnation, Washington.

Seventeen rivers in western Washington had reached flood stage, authorities said. Near Walla Walla, Washington, just north of the Oregon border, the Mill River crested at more than 20 feet (6.10 meters), setting a record, the National Weather Service said.

In western Washington, a tree fell on a car on State Route 18 west of Issaquah on Thursday night, blocking the highway for hours. No one was injured. People living in an apartment building in Issaquah were evacuated Thursday after Issaquah Creek breached its banks and began running under the building.

Snow levels will drop and heavy snow is expected in the Cascade Mountains through Saturday morning, the National Weather Service said. Winds are expected to pick up, too, they said. Snow is also expected in the Blue Mountains, but lower temperatures should stop the snow from melting and ease flooding.

Rivers were expected to drop below flood stage by Saturday morning, authorities said.