Another Willamette Valley town, Turner, was also being threatened by floodwaters. The Marion County sheriff's office said five rescue boats have been sent to assist residents there. To the west of Oregon's Coast Range, residents were being evacuated in the town of Mapleton, with a population of about 900.
Near Issaquah, Wash., a person backing an all-terrain vehicle out of a shed was killed by a falling tree, King County sheriff's Sgt. Cindi West said. Other details about the incident weren't immediately available.
Washington State University in Pullman was closed. The University of Washington also cancelled Thursday classes at three campuses, including Seattle.
The storm caused hundreds of roadway accidents, but no fatalities. The state Transportation Department closed Highway 18 near Issaquah because of falling trees.
"We want to make sure all the limbs that are going to come down, come down," said DOT spokeswoman Alice Fiman in Olympia.
Karina Shagren, a spokeswoman for Gregoire, said even though an emergency declaration has been issued, the National Guard has not been called up. Shagren said that what sparked the proclamation was concern over truck drivers carrying dairy products not being able to drive more than 12 hours a day due to federal regulations.
East of the Cascades, a light snow continued to fall Thursday, and drivers crept along roads slowly throughout the region. Cleanup work at the Hanford nuclear reservation was called off for the day, and the Pacific Northwest National Laboratory closed as well.
At a bus stop near the Seattle neighborhood of Ballard, Canadian transplant Jennifer Hastings waited for the bus to head downtown.
"I didn't buy snow tires. This is Seattle. We were like, 'it doesn't snow here,'" said Hastings, who moved here last year.
Cooper reported from Albany, Ore. Associated Press writers Doug Esser, Ted Warren, Shannon Dininny, Rachel La Corte, Nigel Duara contributed to this report.
- Debate Takeaways: Rubio shaken, Trump not...
- Rubio faces barrage of attacks in Republican...
- Charity parodies — videos tell another...
- 5 things to know about the Super Bowl and sex...
- N. Korea praises launch, others see as covert...
- Rescuers in Taiwan pull out survivors from...
- Over 100 missing, 14 dead as strong quake...
- Pope's sex abuse panel tells survivor to take...
- US adds just 151k jobs in January; 4.9... 29
- Donald Trump calls for Iowa election... 14
- Kentucky Sen. Rand Paul quits 2016 GOP... 12
- Once a bromance, now a brawl: Trump and... 10
- 5 things to know about the Super Bowl... 9
- In a U.S. divided on gun control,... 8
- Clinton's New Hampshire challenge:... 6
- Clinton seeks to cut into Sanders' New... 6