At least one person was killed in a traffic accident during a Winter Storm Zephyr. The weather appears to be to blame for at least one fatal crash Sunday on U.S. Highway 285 southwest of Denver.

The highway was one of the worst for accidents in the storm. Two law enforcement cruisers were also hit along the road in less than an hour responding to other crashes.

Traffic began rolling again across a southern Wyoming artery that had been shuttered for more than 24 hours and officials in Nebraska made plans to move some primary polling locations Monday following Winter Storm Zephyr, which brought up to 3 feet of snow to the Rockies and spawned thunderstorms and tornadoes in the Midwest.

Interstate 80, a major east-west truck route, reopened in Wyoming a day after its closure stranded thousands of travelers and truckers. The interstate quickly became crowded with the trucks that had packed rest areas.

The lingering snow slowed down Monday morning's commute in the Denver area but driving conditions were worse in the mountains.

(MORE: Winter Storm Zephyr Updates | Zephyr Forecast)

Here state-by-state impacts from Winter Storm Zephyr:

Colorado

The snow that began falling on Mother's Day caused some power outages as it weighed down newly greening trees.

Among those affected by the outages was Denver International Airport, where some escalators and elevators temporarily stalled Monday morning. Airport spokeswoman Julie Smith said a backup generator spared the airport any major problems. At least 27 arriving and departing flights were canceled due to the weather, but Smith said there were no major delays. Crews were working overnight to de-ice runways.

The snowstorm has increased the state's avalanche danger.

Ethan Greene of the Colorado Avalanche Information Center says that the new snow is landing on top of a thick hard pack of earlier snowfall. Strong winds can dislodge it and start avalanches. The danger may persist for several more weeks because much of the snow in the Rockies hasn't started to melt.

More than a foot of snow fell in some parts of Colorado's mountains since the storm began Sunday. Eight people have died in avalanches this year in the state.

Wyoming

Intsterstate 80 reopened Monday in the wake of Winter Storm Zephyr, which boosted the mountain snowpack by more than 3 feet in some places.

State Department of Transportation spokesman Bruce Burrows said the shear amount of heavy, wet snow that fell Sunday and strong winds taxed the agency's snowplows and road crews and forced them to close an 180-mile stretch of Interstate 80 between the Nebraska state line and Rawlins

"I wouldn't say it necessarily caught us off guard," Burrows said. "The strength of the event and a relatively unusual amount of precipitation or moisture this late in the year just made it really impossible for us to keep up with it."

Burrows said the interstate in southwest Wyoming had to be shut down because there was no place for truckers to seek refuge in Cheyenne, Laramie or Rawlins in southeast Wyoming.

Public schools and the Laramie County Community College also were shuttered Monday in Cheyenne, where 11.8 inches of snow fell on Sunday. It is the fifth-greatest May snowfall in the city, dating to 1889.

The National Weather Service reported estimated snowfall of up to 39 inches in the Snowy Range and Sierra Madre mountains in south-central Wyoming.

The storm increased the statewide snowpack to 152 percent of median, according to the Natural Resources Conservation Service in Casper. The statewide snowpack the previous week was 132 percent of median.

Nebraska

Up to a foot of snow fell near Harrison in Sioux County on Sunday. National Weather Service meteorologist Tim Trudel said Monday that there was 4 to 6 inches on the ground as of 8 p.m. Sunday north of Kimball, and he expected 1-2 inches to fall there Monday as another portion of a storm system moves through.

Trudel said "it's not too terribly unusual to have snow fall" on May 11 in Nebraska, citing a report from Scottsbluff: The 5 inches that fell there on Sunday bested the 1983 date record of 2.6 inches.

He said westbound Interstate 80 remained closed Monday morning to keep motorists from reaching Wyoming, where travel conditions were even worse.

The Associated Press contributed to this report.

MORE ON WEATHER.COM: Winter Storm Zephyr in Photos

Heavy snow weighs down trees and bushes as a woman runs in Washington Park in Denver on Monday, May 12, 2014. (AP Photo/Ed Andrieski)