A 20-year-old elk hunter from Seattle died when his pickup truck was swept into the Cowlitz River in southwest Washington, authorities said.
Gov. Chris Gregoire declared a state of emergency for 18 counties, authorizing the National Guard to activate and the state Emergency Management Division to coordinate assistance.
More than a dozen Guardsmen were sent late Monday to eastern Skagit County near the Canadian border, with the Skagit River expected to reach record levels, to rescue an unknown number of people, said county spokesman Don McKeehen. Another 150 troops were expected Tuesday.
Those rescued had not heeded a recommendation to evacuate before waters blocked their escape route from several small towns near Concrete, McKeehen said.
In the King County town of North Bend, about 30 miles east of Seattle, the Snoqualmie River slopped over a levee, prompting emergency officials to urge residents of two neighborhoods to evacuate, county spokesman David Tushin said Monday night. He could not estimate how many people might be affected.
A large mudslide near Skykomish, northeast of Seattle, blocked eastbound lanes of U.S. Highway 2, a major east-west route across Washington, while a mudslide earlier Monday near Tacoma delayed an Amtrak passenger train.
Officials at Mount Rainier National Park, which had more than 10 inches of rain in the 24 hours ending Monday afternoon, closed the main park road, turned visitors away and sent employees home early via the only exit road open.
"We want to prevent visitors getting trapped inside the park. The road is vulnerable to washouts in several key places, and there is only one way out," superintendent Dave Uberagua said.
A sheriff's helicopter in Snohomish County, just north of Seattle, rescued several transients stranded on a sandbar where they had been camping. More than 100 students at an environmental camp in southwest Washington were evacuated, for fear that high water would cut access to the camp.
About 200 to 225 elk hunters were evacuated Monday from hunting camps near the Cowlitz River, said Lewis County Sheriff Steve Mansfield. The body of Andy McDonald was recovered late Monday when his truck was pulled from the water.
The National Weather Service warned officials in Skagit County -- where the Guard performed its rescues -- to expect worse conditions than in 2003, when flooding caused $17 million in property damage in Concrete and 3,400 households were evacuated, he said.
The warm-weather rainstorms, propelled by air currents from Hawaii in a pattern called the Pineapple Express, could cause flooding of record proportions, the weather service said. Several rivers had already jumped their banks.
As of early Monday afternoon, Stampede Pass on the Cascade crest east of Seattle had more than 8 inches of rain in the previous 24 hours, while Seattle-Tacoma International Airport recorded nearly 4 inches. Most rivers were expected to crest Tuesday.