Kevin McLeod, co-owner of the Riverview RV Park, wades through floodwaters near a partially submerged car Wednesday, Dec. 9, 2015, after he hooked up a pump to get rid of water that flooded RV's and other vehicles Wednesday morning in Puyallup, Wash.

Kevin McLeod, co-owner of the Riverview RV Park, wades through floodwaters near a partially submerged car Wednesday, Dec. 9, 2015, after he hooked up a pump to get rid of water that flooded RV’s and other vehicles Wednesday morning in Puyallup, Wash.

Ted S. Warren/AP

Washington Gov. Jay Inslee declared a state of emergency Wednesday following extensive flooding and landslides that closed major roadways.

Days of rain have left thousands without power in western Washington and Oregon, and led to some home evacuations.

“There are people in need across Southwest Washington and the rest of the state and we’re here to provide whatever assistance the local communities require,” Inslee said in a statement. “We’re in this together.”

Southwest Washington was hit  particularly hard Tuesday night, as hundreds of Cowlitz County residents were isolated by the surging Kalama River.

Cowlitz County and each of its cities also declared their own states of emergency Wednesday.

Ernie Schnabler, director of emergency management for Cowlitz County, said rain relentlessly poured Tuesday night.

“We were just kind of aimed at with a fire hose, meteorologically speaking,” he said. “It was coming down in buckets. You have seen downpours that maybe last 10 or 15 minutes during a thunderstorm, but it was coming down just like that for hours on end.”

Map: Landslide Risk In The Northwest

Heavy rains have contributed to some significant landslides in the Northwest, including the deadly 2014 Oso landslide. Oregon and Washington lead the nation in landslide mapping, but even their inventories are a patchwork of studies with varied purposes and levels of detail. Use this tool to see past landslides, and future landslide risks near you.  Editor’s note: This map was built in 2014, and the data from government agencies may have updated since then.

A landslide Wednesday afternoon closed the northbound lanes of I-5, the state’s busiest highway, near Woodland, Washington.

State transportation officials also closed a 45-mile stretch of U.S. Route 12 in south central Washington after heavy rains washed out a portion of the road west of White Pass, Washington.

Spokeswoman Summer Derrey said crews were waiting for safe conditions Wednesday before going in to assess the damage and determine how to make repairs. She said the stretch — east of Packwood and just west of Naches — is closed indefinitely.

Inslee directed members of the Washington Military Department to coordinate state responses to the flooding.

According to the governor’s office, Lewis and Snohomish counties were also highly affected by rainy and windy conditions this week.

The Associated Press contributed to this report.