ALBUQUERQUE, N.M. (AP) _ A second day of thick, wet snow stranded travelers along major New Mexico highways on Tuesday and shut down the town of Roswell, where so much snow all at once is an alien presence.

The National Guard was sent out with all-terrain vehicles to help clear major highways, and Gov. Gary Johnson declared a state of emergency for counties in the southeast, opening the door to disaster relief money.

Nearly a foot of snow brought travel to a halt in Roswell, better known as the place where believers insist an alien spaceship crashed 50 years ago. A foot of snow is about as much as Roswell gets in an entire year.

Snow stopped falling at about 8 a.m., but roads in and out of Roswell were still closed by midday and truck stops overflowed with snowbound truckers.

Bill Scaff of Tempe, Ariz., was heading from Ohio to Los Angeles with a flatbed truck and tried to make an end run around the snow by dropping down through Texas to Roswell.

``I decided I would try the southern route and it was just as bad or worse than over there,'' he said from Price's Truck Stop.

``We've got a mess,'' said truck stop employee Thea Bass.

The heavy snow also pulled down power lines in Roswell, leaving many people in the dark or without heat in the city of about 48,000 people in southeastern New Mexico. The mercury fell to 30 degrees at Roswell, which sits on the Pecos River at an elevation of about 3,700 feet.

``We were too shorthanded to go out and check on all of the elderly people without electricity,'' said Becky Hamner, a Chaves County sheriff's administrator. ``The sheriff's posse worked all night rescuing who they could.''

There was no immediate word how many people had no power; utility officials did not immediately return calls.

The storm headed eastward during the afternoon, spreading more snow across the Plains from the Texas Panhandle into Kansas. The Oklahoma Panhandle had 8 inches by early afternoon, and thunderstorms resulted in flash flood watches for parts of Texas and Louisiana.

The storm had piled up as much as 20 inches of snow Monday on northern Arizona's San Francisco Peaks near Flagstaff and on top of Mount Lemmon outside Tucson in the south.

And forecasters warned that yet another storm would probably hit the Southwest on Christmas Eve.

Cold air blew into Southern California, dropping temperatures Tuesday morning to 35 at seaside Santa Barbara and 46 in downtown Los Angeles. Freezing temperatures to the north included 21 at Lancaster and 26 at Paso Robles.

The cold didn't last long enough to damage citrus crops, and daytime highs jumped back into the normal 60s and 70s, but more cold was forecast.

The snow made travel difficult across large parts of New Mexico.

Most of the 170-mile stretch of Interstate 40 from Albuquerque to the Texas state line was shut down, along with several state highways through mountains and the high desert.

Farther west, numerous accidents slowed travel on I-40 across northern Arizona, with some people delayed five to six hours east of Flagstaff.

In southwestern New Mexico, a 60-mile stretch of I-25 from Socorro to Truth or Consequences was closed during the night.

In the Northeast, meanwhile, snow fell across much of upstate New York and northern New England, with up to 8 inches in Maine by midafternoon. Schools opened late or closed in upstate New York, Connecticut, Massachusetts and New Hampshire.