By Keith Coffman
DENVER, March 5 (Reuters) - An avalanche tore down a southwestern Colorado mountainside on Wednesday burying five snowmobilers, one of whom remained unaccounted for, in a winter season that has already left at least 19 people dead, authorities said.
The group set out from the town of Mancos and were snowmobiling in the rugged San Juan Mountains in the western state's remote Four Corners area when the slide occurred at an elevation of 10,500 feet, Montezuma County Undersheriff Lynda Carter said.
Four were in good condition, but a fifth man, identified as Anthony Robert Yates, was still missing, Carter said. The search for Yates will resume at daybreak on Thursday.
Avalanches have killed at least 19 people in the United States so far this winter, approaching an average of 28 people killed annually by snow slides in the United States, government data shows.
Experts attribute the rise in deadly slides to heavy, wet snowfall that has blanketed the mountain West in recent months after an extended dry spell weakened an early season snow base.
A ski patrol official conducting research died in a avalanche on Tuesday in Conejos County, Colorado.
A woman who was buried alive along with her husband by an avalanche that swallowed their house late last week in Missoula, Montana, died of her injuries on Sunday night. (Reporting by Keith Coffman in Denver; Editing by Eric M. Johnson and Kevin Liffey)