A powerful late winter snowstorm intensified over the central Rocky Mountains today with heavy snow and wind leading to airport and road closures, power outages and avalanche warnings in parts of Colorado, Wyoming and Nebraska.

The National Weather Service in Wyoming called it a “historic and crippling” winter storm that would cause extremely dangerous to impossible travel conditions through at least early Monday.

Major roads southeast of a line that crosses diagonally from the southwest corner of Wyoming to its northeast corner were closed today, including roads in and out of Cheyenne and Casper.

Over 2 feet of snow had fallen just outside Cheyenne by 9:30 a.m. Saturday, the weather service reported, while other areas around the city had seen 16 to 19 inches. A SNOTEL site at Windy Peak in the Laramie Range reported 52 inches of snow in a 24-hour period ending this morning, the weather service said.

A person who answered the phone at the Love’s Travel Stop in Cheyenne, but declined to give his name, said 98 trucks were stranded there. They were taking fuel out a can at a time to fill up generators on the trucks to keep their refrigerators or freezers running, he said.

Interstate 80 was closed across southern Wyoming and into the Nebraska panhandle, where a foot of snow was reported just north of Kimball, Nebraska. Interstate 25 was closed north from Fort Collins, Colorado, to its end at Buffalo, Wyoming.

At Denver International Airport, the runways were closed just before noon today due to blowing snow and poor visibilities.

“Many flights have already been canceled so the runway closures have minimal impacts,” airport officials said in social media posts. A foot of snow fell at DIA on Saturday and another foot was expected today.

The Northern Colorado Regional Airport that serves the Fort Collins and Loveland areas was closed today morning after also receiving a foot of snow, according to the airport’s social media accounts.

An avalanche warning was in effect today for the Rocky Mountains west of Fort Collins, Boulder, Denver and Colorado Springs where “intense snowfall will cause large and destructive avalanches,” Colorado Avalanche Center said. The center warned that avalanches could happen in unusual locations and recommended against traveling in the backcountry.

An avalanche blocked Colorado Highway 14 in north-central Colorado today, the Department of Transportation said.

Nearly 32,000 Excel Energy customers were without power Sunday in north-central Colorado, while smaller outages were reported in the same area by the Poudre Valley Rural Electric Association

Rocky Mountain Power in Wyoming has reported several outages. At one point overnight, service was interrupted to nearly 2,600 customers in Casper and Glenrock and 2,800 customers in Lander. Just under 1,000 people were without power in the Casper area today.

The power company expects more service interruptions as the storm continues.

“Heavy snow and drifting conditions from wind is expected to make travel and repair work increasingly difficult today,” Curt Mansfield, vice president of operations for Rocky Mountain Power said in a statement today.