The upper end of an avalanche inside the Snowbird Ski Resort on Sunday, March 4, 2012.

MOAB — The body of an 18-year-old Colorado man buried in a Saturday avalanche in Grand County was recovered by searchers Sunday afternoon about the time a separate avalanche injured a snowboarder at the Snowbird Ski Resort.

Additional avalanches near Snowbird closed the highway in Little Cottonwood Canyon Sunday from about 11:30 a.m. until just after 4 p.m., according to Unified Police, keeping people already at the canyon resorts from leaving, and preventing many others from getting to the canyon.

A group of four snowmobilers from Colorado were riding in the Beaver Basin area of the LaSal Mountains when the Saturday avalanche was triggered about 10:30 a.m. "They said they kind of saw a white mist and all of a sudden, here it came," said Grand County Sheriff Steven White.

The name of the man killed has not yet been released. White said about 40 searchers and another 20 support personnel worked through the day Sunday to find the man buried in about 12 feet of snow. His body was located about 2 p.m. Sunday, about five feet from where the snowmobile was found at a depth of about 10 feet.

"It took a lot of digging," the sheriff said, adding that the slide area of about an acre was in a very steep ravine where snow depths are about 30 feet. No official determination had been made as of about 4:30 p.m. Sunday what triggered the avalanche that killed the man, though there was no obvious cause other than the snowmobiles, the sheriff said.

The Snowbird slide was triggered about 2 p.m. in the Blackjack area, a west-facing ski run off the Peruvian Ridge that separates Snowbird from Alta Ski Area. The slide was 2- to 3-feet-deep, 80-feet-wide and about 600-feet-long.

A 24-year-old snowboarder was caught in the slide. He was taken to Intermountain Medical Center. Snowbird spokeswoman Emily Moench said the man's injuries are not life threatening. No other skiers were injured.

The Snowbird avalanche was inside the resort in an area normally controlled for avalanches prior to opening for skiers, and avalanche-control measures were taken following the last snowfall, according to Snowbird. Moench attributes the cause of the avalanche, in part, to the rapid warming following the most recent snowfall.