Eight of the nine skiers missing in California after an avalanche have been found dead and one remains missing in horrific blizzard conditions, police said on Wednesday.

Rescuers have been desperately searching for the group which was caught in the avalanche early on Tuesday on Castle Peak in the Tahoe area. Earlier, six skiers were found alive.

"We are still looking for one of the members at this time," Nevada County Sheriff Shannan Moon said, cautioning that the storm is hampering any movement.

"Extreme weather conditions I would say is an understatement: lots of snow, gale-force winds, winds making it impossible to see," Moon said.

Blackbird Mountain Guides, the company leading the doomed backcountry trip, said the 11 clients and four guides had been staying at the Frog Lake huts since Sunday and were "in the process of returning" back to base.

Over 40 first responders launched the search, according to officials, including "highly skilled rescue ski teams" from both Boreal Mountain Ski Resort and Tahoe Donner's Alder Creek Adventure Centre.

But after quickly finding the six known survivors, the teams came up empty handed.

Experts had warned of severe avalanche risk.

Placer County Sheriff Wayne Woo pleaded with the public to stay away until the weather clears.

"Please avoid the Sierras during this current storm and in the upcoming days, avoid mountain travel. It's treacherous."

Sheriff's office Captain Russell Green also told local station KCRA that backcountry skiing is inherently dangerous.

"People go out and use the backcountry at all times," Green said. "We advise against it, obviously, but I wouldn't say that it's uncommon. Not that it was a wise choice."

The Colorado Avalanche Information Centre has tallied six US avalanche fatalities so far this season, including one in Castle Peak in January. (AFP)



Edited by Cecil Wong