Updated

A levee break flooded hundreds of homes Saturday as the storm that has pummeled the West Coast with high wind and heavy rain dropped a thick blanket of snow on the Sierra Nevada on Saturday.

Thousands of people had no power in three states and thousands more had been told to leave their homes in mudslide-prone areas of Southern California.

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Up to 44 inches of snow had fallen in some parts of the Sierra Nevada, the National Weather Service said Saturday morning. Forecasters expected the storm to dump as much as 10 feet at higher elevations of the mountain range by Sunday.

East of the Sierra in Nevada's Lyon County, a levee broke early Saturday along an agricultural canal, releasing water as much as 3 feet deep into the town of Fernley and stranding about 3,500 people, authorities said. Rescuers were using school buses, boats and helicopters.

No injuries were reported.

The Fernley area had gotten heavy rain on Friday plus snow.

"It was a mess up there last night," said Chuck Allen of the Nevada Department of Public Safety. "It's so cold here. The snow is about 2 inches in depth and the temperatures are right near the frigid mark both for the rescuers and rescuees."

Flights were grounded Friday and trucks overturned in Northern California as wind gusted to 80 mph during the second wave of the arctic storm that has sent trees crashing onto houses, cars and roads. Hundreds of thousands of customers lost power from central California into Oregon and Washington.

In the south, residents of Orange County canyons that were stripped by wildfires last fall — making them susceptible to mudslides — nervously watched weather reports to learn when they might be hit by the fierce wind and heavy downpours forecast for the area.

"There's a little bit of a letup right now in the rain, but there's still a huge band of rain that's going to come in today," Ted MacKechnie, a National Weather Service forecaster, said Saturday morning.

About 3,000 people in four canyons had been told to leave their homes by 7 p.m. Friday, Orange County fire Capt. Mike Blawn said.

However, there was no indication how many obeyed. "We have been hearing that very small percentage of them actually evacuated," Battalion Chief Kris Concepcion said.

Flash flood warnings were in effect Saturday for broad swaths of Southern California, including most of Los Angeles County and southeastern Santa Barbara County.

Homeowners in Southern California and the Central Valley stacked sandbags and hay bales around their homes to keep out floods. A voluntary evacuation was in effect at an apartment complex northwest of downtown Los Angeles because of flooding and a small mudslide.

In the Sierra Nevada, where a winter storm warning was in effect, the California Department of Transportation said Interstate 80, the main east-west link between Northern California and Nevada, was reopened Saturday, but tire chains were mandatory on a 60-mile stretch. While the highway was shut down during the night, the Red Cross set up a 200-bed shelter in Truckee for stranded motorists.

Winter storm warnings also were issued for mountain areas in Colorado, where forecasters said several feet of snow is possible this weekend.

In the Sierra National Forest, three missing members of a Clovis family were found in good condition just after nightfall Friday, ending a daylong search, when rescuers found them with three other hikers who had apparently gotten trapped by the snowfall.

The state opened its emergency operations center Friday to coordinate storm response, and Gov. Arnold Schwarzenegger said he had spoken with Homeland Security Secretary Michael Chertoff by phone.

About 440,000 homes and businesses from the Bay Area to the Central Valley were in the dark early Saturday, down from about 1.5 million the day before. It could be days before all the lights are back on, Pacific Gas & Electric officials said.

The sprawling storm system also toppled trees and cut power to thousands of customers in Washington and Oregon.

"A huge tree, over 100 years old, just fell across the house. It just wrecked the whole thing," Faye Reed said of her daughter Teenia's damaged home north of Sacramento. "They won't be able to live in it. The whole ceiling fell in, and now it's raining inside."