LONGMONT, Colo. - A powerful late-autumn storm dumped up to 24 inches of snow in the Colorado mountains on Tuesday before barreling onto the plains, prompting airlines to cancel 425 flights at the Denver airport and leaving hundreds of miles of highways slippery with snow and ice.

The snow tapered off Tuesday afternoon as the storm moved northeast, leaving behind drifts up to four feet high.

"It's going to be western Nebraska's turn next," National Weather Service meteorologist Todd Dankers said. "It's going to end up eventually in Minnesota."

It was the first big storm of the season for most of Colorado and Utah. Schools closed in some towns in at least four states.

Some flights at Denver International Airport were more than four hours late after at least seven inches of snow fell there, airport officials said.

More than 600 miles of Colorado interstate highways were snowpacked or icy, and gusts as strong as 58 m.p.h. left near-whiteout conditions in isolated areas of Colorado's eastern plains, Dankers said. Few highways were closed, however.

A snowplow slipped off a highway in the foothills west of Boulder early Tuesday and landed upside-down in a creek, but the driver wasn't injured.

The wind piled up drifts three to four feet deep in the small northeastern Colorado town of Merino. Schools and the town offices were closed but some businesses opened as usual.

"I think we're just more used to it," said Jada Gettman, owner of Grandpa's restaurant in Merino, which was open. "The snowing and blowing doesn't affect us as much."