An avalanche on the back side of Whitefish Mountain Resort killed two backcountry skiers Sunday and searchers combed the slide area for other possible victims, Flathead County Sheriff Mike Meehan said.

Meehan said the avalanche occurred on Fiberglass Hill in the Canyon Creek drainage.

Emergency responders were alerted to the avalanche around noon, and more than 100 search and rescue people were quickly called to the scene.

Meehan released a statement indicating the body of a victim was recovered at about 1:18 p.m. and a second body at 4:16 p.m. No names were released.

The number of people missing in the slide is unknown, Meehan said early Sunday evening.

"At this time, there are conflicting statements to responders about how many more victims might have been buried in the avalanche," he said. "If the scene of the avalanche is safe for rescue workers, rescue efforts will continue throughout the night."

In addition, three men caught in an avalanche while snowmobiling in the Star Valley south of Jackson have been found dead.

The Star Valley Search and Rescue team found the three men in the Cottonwood Lake area Saturday.

The Lincoln County sheriff's office hasn't released the men's names.

A dispatcher at the sheriff's office who didn't give her name said Sunday that she didn't know when the avalanche occurred. No further details were available.

The sheriff described the avalanche as "massive," and said the slide area began high on the mountain side, is several hundred feet wide and piled up between 25 and 35 feet of snow by the time it came to a stop.

Avalanches have killed at least 17 people across the West since Nov. 12. The national annual average for avalanche deaths is about 25. Thirty-five people were killed nationwide in avalanches in the 2001-2002 season, the most on record, according to the U.S. Forest Service.