A kayaker paddles on the flooded Interstate 5 in Chehalis, Wash. A storm that battered the Pacific Northwest for two days moved on Tuesday, leaving behind flooded homes, fallen trees and washed-out roads, including the region's largest highway.

Seattle ? Residents of Oregon and Washington, slammed by a huge Pacific storm packing hurricane-force wind, struggled Tuesday to escape flooded communities, dig out of mudslides and navigate road closures.

Severe flooding shut down a 20-mile stretch of Interstate 5 near Chehalis, Wash., cutting off a main connecting route between Portland and Seattle. The highway – covered by eight feet of water after a dike broke – will be closed at least through Thursday, forcing lengthy detours.

Thousands of trees were downed, as were power lines and communication links.

Southwest Washington was hit especially hard. By late Tuesday, 1,500 evacuees squeezed into three emergency shelters in Grays Harbor County. “We haven’t even begun damage assessment yet,” said Ken Walkington, sheriff’s operations deputy.

States of emergency were declared in Washington and Oregon, and officials anticipated a massive and costly clean-up effort.

“Yesterday was about ‘how do we contain problems,'” Washington Gov. Christine Gregoire said at a news conference Tuesday. “Today, it’s the human stories that we are beginning to see.”

At least five deaths were blamed on the storms, which battered the Northwest beginning Sunday.

Wind gusts reached up to 100 mph on some parts of the coast; as much as 10 inches of rain fell in some areas.

Two men died in Grays Harbor County, one when a tree fell on him in Aberdeen and one who had medical problems related to a power outage in Montesano. A third person died in Mason County when a mudslide buried him in a house in a remote area about 20 miles north of Shelton. According to the King County Sheriff’s office, two hikers were found dead Tuesday from an avalanche triggered by rain in the Cascade Mountains.

“This is at least a 50-year storm,” said Dean Byrd, Mason County Sheriff chief deputy. “We got a 1-2-3 punch: Snow on the weekend, then high winds and rain.”

Returning from a helicopter tour of flooded Vernonia, Ore., where 300 residents had to be rescued after torrential rains, Oregon Gov. Ted Kulongoski cautioned that it would take time for a complete recovery.

“You can see it in the faces of the people that this is the Christmas season,” Kulongoski said. “They are supposed to be celebrating and looking forward to a very joyous time. They now know it’s going to be a period of time to recover and try to get their lives back together.”

In Washington, more than 150 people were rescued by helicopter in Mason and Lewis counties.

State transportation officials set up a lengthy detour around the closed section of Interstate 5. Officials advised motorists to avoid travel between Seattle and Portland until the waters recede.

Across the region, winds have died down and the rains have eased. The forecast also improved, with some lighter shower activity expected and drier, sunnier weather predicted for the end of the week.