The powerful winter storm that lingered over Colorado, punishing it with snowdrifts up to 10 feet high, had barreled out of the Plains states Monday, leaving thousands of homes and businesses without power.

At least 12 deaths were blamed on the storm, most in accidents on icy roads.

By Monday morning, no snow was falling across the middle of the nation as the huge storm that once stretched from Canada to Mexico had picked up speed and moved well to the east. The remains of the weather system poured rain along a line from Florida to New York, with snow in parts of New England.

A fleet of small planes canvassed snow-covered roads southeast of Denver on Sunday, searching for travelers stranded in areas where roads were blocked by snow drifts that measured 10 feet high. National Guard troops rescued at least 44 people.

"This is a very significant storm; it's in the record books," said Scott Blair, a meteorologist with the National Weather Service.

The storm struck on Thursday, but many roads in eastern Colorado remained closed Sunday. Interstates 70 and 25 reopened Sunday evening.

The National Guard was also mobilized in Kansas, where more than 44,000 homes and businesses were blacked out and stretches of more than a dozen highways were closed. Kansas Gov. Kathleen Sebelius declared an emergency.

Parts of Kansas got up to 32 inches of snow and wind piled it into drifts 15 feet high. The state Highway Patrol used an airplane to find stranded motorists.

Al Butkus, spokesman for the Kansas utility Aquila Inc., said it could be a week before power is restored to all customers.

"We've gotten 3 inches of ice on wires and connectors, and that ice stays there until it gets above freezing," Butkus said. "And the temperatures aren't moving above freezing."

In New Mexico, up to 2 feet of snow fell on Albuquerque and authorities had to clear a logjam of vehicles stuck along Interstate 40.

During the weekend in rural northeastern New Mexico, 44 motorists from as far as away as Louisiana took shelter at the home of Christine and Randy Glover after getting stuck in 3- to 4-foot drifts along U.S. 56, between Springer and Clayton.

"We just were in the right place at the right time," said Christine Glover. The Glovers had to guide some of the travelers to their house by radio because of whiteout conditions in blowing snow.

The Oklahoma Panhandle measured up to 18 inches of snow, closing major roads, and at least 5,000 utility customers were without electricity. Some 15,000 homes and businesses were in the dark in Nebraska.

The bulk of the storm hit the western and central Plains. Farther north, parts of southern Minnesota had 10 inches of snow.

Ten people were killed since Thursday in traffic accidents in Colorado, Texas and Minnesota. Four of those fatalities occurred Sunday in eastern Minnesota.

A tornado spawned by the same weather system killed one person Friday in Texas, and a Kansas man was reported dead Sunday in a rural home where a generator apparently had been in use during the blackout.

Warmer weather was forecast for later in the week in the region.