Undated (AP) _ Nearly 3 feet of snow shut down schools and most travel Wednesday in northern Arizona and the governor declared an emergency in two counties as a massive storm spread ice and snow from the Southwest into the western Dakotas.

A layer of ice briefly closed a coastal highway south of Los Angeles, ice made travel hazardous around the casinos of Las Vegas, Nev., and motorists needed escorts to drive through some Southern California mountain passes.

Workers using tracked and four-wheel drive vehicles rescued at least nine people stranded in hard-hit central Arizona, where authorities planned to use 5-ton National Guard trucks to reach about 50 people reported unharmed but eager to leave a Baptist camp near the Mogollon Rim.

Rescuers searched the mountains and ocean for two private airplanes that disappeared during storms over Southern California.

A twin-engine Piper Seminole with two people aboard disappeared from radar screens Tuesday off Santa Monica, Coast Guard Petty Officer Leo Kay said. And a single-engine Cessna 206 with two people aboard vanished Monday during storms over the San Gabriel Mountains, Civil Air Patrol Lt. Col. Ernie Pearson said.

''It seems like it (snow) has shut down Arizona to some extent. If you don't have chains you aren't going anywhere,'' said Alexis Smith, a receptionist at the Bellemont Truck Center on Interstate 40 at Bellemont, Ariz., between Flagstaff and Williams. She said that area had 32 inches of snow on the ground by early Wednesday.

The storm spread snow from the Southwest into the western Dakotas, and winter storm warnings were posted for parts of Montana, Colorado, New Mexico and Arizona, with up to a foot of additional snow possible at some higher elevations, the National Weather Service said.

The high country of northern Arizona was hardest hit by the storm. Flagstaff, at an elevation of about 7,000 feet, had 25 inches by noon Wednesday and Prescott, to the southwest at around 5,000 feet, had 26 inches. It was the heaviest snow in the region in seven years.

Schools were closed in both cities Wednesday and more snow was forecast.

Arizona Gov. Evan Mecham declared a state of emergency for Gila County and Yavapai County, which includes Prescott, to make state aid available.

Most main streets in the former territorial capital were plowed Wednesday but ''some side streets still have two foot of snow on them,'' said olice Lt. Angelo Lira. In spite of the snow, the city warmed to 55 degrees with sunshine.

In Strawberry in central Arizona's high country, ''The big problem isn't driving, it's walking,'' said Jean Turner, operator of Turner's Strawberry Lodge. ''You can't even go out to your wash house without being waist-deep in snow.''

By mid-afternoon Wednesday 30 inches of snow was on the ground at Payson, 20 miles south of Strawberry, and ''a lot more'' fell in outlying areas, said Gila County sheriff's Lt. Harry Cain.

Cain said deputies used ''snow cats'' to rescue six people who became stranded while cutting wood northeast of Payson.

Harry Stevens, Yavapai County emergency services director, said the ''Jeep Posse,'' a volunteer group, rescued three people.

''We got them out and the Salvation Army put them up,'' said Stevens. ''In a couple of weeks we'll go back and see if we can get their car out. It got buried.''

Fairfield Snowbowl, a ski area in the mountains 10 miles northwest of Flagstaff, got 42 inches Tuesday. ''The snow's up to their chests,'' manager J.R. Murray said of skiers.

Other snow amounts included 28 inches at Lander, Wyo.; 24 at Red Lodge, Mont.; and 24 at Brian Head, Utah. Los Alamos, N.M., got 6 inches for a total so far this winter of 121, just a half-inch shy of its record for an entire winter.

The snow closed 100-mile sections of I-40 across northern Arizona and I-17 from Flagstaff south toward Phoenix on Tuesday. Both were reopened Wednesday, but only to vehicles with snow tires or chains.

On the southern edge of the storm, rain drenched Arizona's deserts and police closed a number of flooded streets in Phoenix. But farther south, at Nogales on the Mexican border, 2 inches of snow had fallen and schools were closed in surrounding Santa Cruz County.

In Southern California, I-5, the state's main north-south artery, was closed overnight.

The Pacific Coast Highway was closed for nearly two hours Wednesday at Huntington Beach, on the south side of Los Angeles, because of hail and ice, police Officer Dennis Hashin said.

The storm also spawned water spouts that capsized some small boats in San Diego Bay and lightning that burned a four-story, antique-filled house belonging to newspaper publisher Randolph Hearst.

Utility officials said electricity was restored by Wednesday to 122,000 customers affected by two days of outages caused by lightning.

Nevada had border-to-border snow Wednesday, including a rare dusting at the gambling settlement of Laughlin, in the state's normally mild and dry southern tip.

Winnemucca, Nev., dipped to a record low of 3 below zero.

Up to 19 inches of snow fell in the mountains of Colorado and avalanche warnings were issued for the southern and central mountains.