Winter storms that have brought heavy snow and rain to the western US have killed at least three people.
Up to 5ft (1.5 meters) of snow has so far fallen on California's Sierra Nevada mountains, and more snowfalls are expected in the coming days.
One county in Nevada was declared an emergency area after a levee burst, flooding hundreds of houses.
Hundreds of thousands of homes and businesses are without power in California, Oregon and Washington.
A woman was killed by a falling tree in Oregon, and a falling branch killed a transport worker in Northern California.
In Los Angeles another woman died when her vehicle was swept into a flood channel. Rescuers found her boyfriend clinging to a tree.
In Lyon County, Nevada, about 3,000 people were stranded after a levee along a canal broke early on Saturday, flooding parts of the town of Fernley. Thousands of residents had to flee their homes.
As waters receded late on Saturday, the town's mayor reported damage to at least 300 houses, and Nevada governor Jim Gibbons declared the county an emergency area.
California and Nevada officials have closed nearly 100 miles (160km) of Interstate 80 - the main east-west link between northern California and Nevada - because of poor visibility.
California Governor Arnold Schwarzenegger has declared emergencies in three counties hard hit by the storm.
In southern California, areas denuded by October's forest fires were bracing for flooding and mudslides.
Although blizzard warnings have been now downgraded, authorities are urging all non-essential travel be postponed.