New Year's travelers jammed the Denver airport, trying to get out of town ahead of a snowstorm that caused flight cancellations and threatened to close runways and gum up the United States' busy holiday travel season for the second time in a week.
Managers at the United States' fifth-busiest airport drew up snowplowing plans, and airlines urged ticket-holders on Thursday to flee Denver early or delay departures until after the storm. United Airlines and Frontier, which together account for 80 percent of traffic at Denver International Airport, canceled 322 flights for Thursday evening and Friday morning.
By Thursday night, 10 inches (25 centimeters) of snow had been recorded in the Denver area, and snow falling at a rate of 4 inches (10 centimeters) an hour piled up 28 inches (71 centimeters) in the foothills west of the city.
The heavy snow forced officials to close several major highways in northern Colorado, including Interstate 25, the main north-south route, about 60 miles (100 kilometers) north of the city near Wyoming. Accidents on Interstate 70 blocked travel on the state's main east-west route west of Denver.
Gov. Bill Owens again declared a statewide disaster emergency, just a week after a pre-Christmas blizzard shut the airport for two days, stranded 4,700 holiday travelers and backed up flights around the country.
Bus line Greyhound also canceled all trips out of Denver on Friday and more cancelations could follow this weekend.
The broad storm stretched from the Rocky Mountains into the western Plains; winter storm warnings were in effect for parts of Colorado, Wyoming, Texas, western Nebraska and Kansas, and New Mexico.
The airport and airlines called in extra workers, and security lines moved relatively quickly. But long lines formed at ticket counters as travelers tried to adjust their plans. The Frontier line snaked across the cavernous terminal and wrapped around behind the lines of other airlines on the other side of the building.
Frontier waived its usual change fee to encourage passengers to catch earlier flights, the AP says.
Federal courts closed early, as did many government offices and businesses in Denver and other cities in the state's main population corridor along the Rocky Mountain Front Range.
In New Mexico, the storm forced officials Thursday to close parts of two interstate highways. Numerous crashes were reported along both, state officials said.
In California, another powerful winter storm left tens of thousands of people without power on Thursday as winds gusted to near-hurricane force and blowing snow closed a stretch of a highway in the mountains north of Los Angeles for 11 hours. It reopened Thursday morning, the AP says.
Forecasters in California warned of dangerous winds, with gusts over 80 mph (50 kph), through Friday morning in the region's valleys and mountain passes.