OMAHA, Neb. - A powerful winter storm that covered parts of Colorado with up to 6 feet of snow crept east across the Plains Saturday, knocking out electricity to thousands in Nebraska as the blanket of heavy, wet precipitation downed power lines and made travel treacherous.

Nebraska got more than a foot of snow, and forecasters predicted the storm would drop several inches Saturday in central Iowa before gradually weakening as drier air mixes in and the front continues east.

In York, Neb., Denise Smart spent her Saturday running the register at a mostly empty gas station near I-80 because few people were out in the snow.

"It was loads of fun getting here this morning at 6:30," Smart said.

While travel was difficult throughout the path of the storm, it caused the most problems in Colorado, where Interstate 70 was closed between Denver and the Kansas border until Saturday morning. More than 600 flights were canceled Friday in Denver.

All winter storm warnings expired in Colorado by Saturday afternoon, but warnings remained in place for eastern Nebraska and central and southwestern Iowa.

The National Weather Service said snowfall across the Denver area ranged from 14 to 20 inches. Nearly 4 feet covered the Pinecliffe area, while there was 18 inches near Boulder and 14 inches in the capital city itself. Several towns in eastern Colorado reported more than a foot of snow.

Ski resorts that have suffered below-normal snowfall this year welcomed the snow, but some benefited more than others. Echo Mountain near Denver received 55 inches of new snow, but the storm only dusted larger resorts in the central Colorado mountains.

The downside of all that fresh snow is greater potential for avalanches. The Colorado Avalanche Information Center reported 2 feet or more of new snow could easily overrun the weak, existing snow pack.

A band of heavy snow stalled over central Nebraska Friday, dumping more than 20 inches in rural McPherson County. A wide swath of Nebraska generally along Interstate 80 received 8 to 12 inches of snow on Saturday.

The highways in Nebraska and Iowa generally remained open during the storm except when accidents or downed power lines blocked the way, but officials urged people to stay off the roads if they didn't have to travel.

"This was an awful wet snow," said National Weather Service forecaster Dave Fobert.

Farmers in Nebraska and ranchers in drought-stressed eastern Colorado were grateful for the snow's moisture. But the high-moisture content also created problems because of the weight of the snow.

The heavy, wet snow caused tree limbs to break and knocked down power lines across Nebraska. More than 15,000 customers, mostly in southeast Nebraska, were without power around midday Saturday, but that number had shrunk below 10,000 by midafternoon.

Utility officials said the fresh snow initially made it difficult to make the needed repairs.

The weight of the snow also made homeowners work hard to clear their driveways.

"It's terribly heavy. It's even hard to move with a snow blower," said Faye Reiss, who lives in Minden, Neb. Reiss watched her snow-removal contractor struggle to move the snow Saturday.