A Christmas Eve blizzard howled across Colorado and Wyoming yesterday, leaving up to 40 inches of snow and stranding thousands of holiday travelers, while flood-ravaged towns in the Midwest watched rivers rise and residents began evacuating low-lying areas.

With snow continuing at an inch or more per hour, a state of emergency was declared in Denver and surrounding communities and the National Guard was called out. The Colorado State Patrol formally closed every major highway east of the Continental Divide.

"That means travel at your own risk," said Capt. Dennis Kennaugh. "We're immobilized as far as emergency and medical assistance goes."

Tornadoes skipped across Arkansas, Oklahoma, Missouri and Mississippi, killing one person in Arkansas, injuring at least 16 others and causing extensive damage. Less than 24 hours earlier, more than a dozen tornadoes leveled homes and businesses and injured more than three dozen people in Arkansas, Missouri and Oklahoma. Damage was estimated at $10.6 million.

The first big storm of the winter, which contributed to 14 deaths when it blasted the West Coast earlier this week, is "a real doozy," said Ryan Tilley of the National Weather Service in Kansas City. The death toll from a week of storms was at least 35 nationwide.

More than 40 inches of snow smothered parts of Yellowstone National Park. Two feet of snow covered Casper, Wyo. Wondervu, Colo., southwest of Boulder, received a foot of snow in four hours overnight.

Maintenance crews at Denver's Stapleton International Airport gave up trying to keep even one runway clear, and the airport, one of the 10 busiest in the nation, was closed.

In Atlantic City, Wyo., 80 miners at a U.S. Steel plant were stranded at work because of blowing snow. But spirits were high and food freezers full, a security guard reported.

Few traffic accidents were reported, apparently because the holiday kept many people at home, but snow plows were sent out to reach up to 10 vehicles trapped by drifts on Interstate 15 in eastern Idaho.

About 300 people stranded on Interstate 70 east of Denver were rescued by the State Patrol and taken to a public school at Deer Trail. Officials said there was plenty of food.

The storm, bearing winds up to 50 mph, was in Nebraska last night and drifting slowly toward the Great Lakes.

"We're looking at a very dynamic winter storm system with a lot of moisture in the atmosphere for it to work with," said Tilley. "There's likely to be much more precipitation."

At Stapleton International, news that howling wind and a foot of snow had prompted the first shutdown of the airport since 1954 sent travelers scrambling at first for new flight bookings. Soon, however, ticket counters closed, too, and customers looked for ways to pass the time. Santa Claus put in an appearance at The Timberline bar and received a rousing ovation.

Grounded travelers lined up at pay telephones as relatives and friends were contacted about the unexpected change in plans.

A large number of military personnel on holiday leave were caught at Stapleton by the storm. Most seemed determined not to return to base.

Eventually the airlines sealed off all concourses and many of the would-be travelers left, apparently to hole up in hotels just west of the terminal.

In the lower Midwest, flash flood watches were posted for parts of Illinois, Missouri, Arkansas, Texas and Kentucky.

Rivers and creeks in southeastern Missouri, inundated three weeks ago by record floods, were engorged by up to three inches of rain and began creeping over their banks. People living in low-lying areas of Marble Hill were evacuated.

"Everyone's moving out or sandbagging again. It's a frantic, day-before-Christmas effort," said a volunteer answering the telephones at the Bollinger County sheriff's office.

Water was reported three feet deep in some sections of Piedmont. About 100 people were taken to a relief shelter in the Masonic Temple.

In Salem, Ill., where the normally placid Town Creek was swollen by four inches of rain, city officials began preparing evacuation shelters for residents of a mobile-home park threatened by floodwaters.

Tornadoes and high winds ripped through southern Tulsa, Ketchum and Wright City, Okla., yesterday, damaging more than 50 homes, officials said. The winds caused at least $250,000 in damage to Wright City, and a Tulsa couple and their year-old son were hospitalized after their trailer overturned.

In southwestern Arkansas, battered Thursday by tornadoes that caused more than $5 million damage to Texarkana, the mayor of Malvern imposed a 9 p.m. curfew to keep looters and sightseers out of damaged neighborhoods.