Eight people died after an avalanche struck near Castle Peak in the Sierra Nevada mountains on Tuesday, and rescue teams are searching for a ninth who is presumed dead. Six members of the 15-person ski group have been rescued.
The "football-field sized" avalanche, which was the deadliest in modern California history, hit during the popular "ski week" holidays in the state.
Sisters Caroline Sekar, 45, of San Francisco, and Liz Clabaugh, 52, of Boise, Idaho, were among those who died, their brother told the New York Times.
McAlister Clabaugh, 50, said that many in the group of 11 skiers had been friends since university and would regularly meet for ski trips.
"These are two of the best people I've ever known," Clabaugh said. "They were incredible sisters, mothers, wives and friends. And the idea that they are both gone is, I don't even know how to put it into words."
Max Perrey, the mayor of nearby Mill Valley, told local media that some of the 11 clients on the ski trip, including at least one who died, were mothers from his city, which is in nearby Marin County.
One of the deceased was the spouse of someone on one of the search-and-rescue teams, making continued rescue efforts "challenging emotionally", according to Sheriff Wayne Woo, from neighbouring Placer County.
Three guides from the Blackbird Mountain Guides, who were leading the group back from a three-day backcountry skiing expedition, were killed in the avalanche, according to the company.
Sugar Bowl Academy, a ski school in Placer County, California, said multiple members of its community had died in the avalanche but declined to identify them due to ongoing search efforts.
"Emergency responders are still working to recover all of the victims and are not at this time sharing the personal details of the victims and the survivors out of respect for the families affected," the academy said.
"We are an incredibly close and connected community," executive director Stephen McMahon said. "This tragedy has affected each and every one of us. The depth of support for the families whose lives have been changed forever reminds us of how special this community is."
The avalanche swept away 15 people who were making their way back from the ski trip.
Rescuers, stymied by inclement weather, so far have located the bodies of seven women and a man killed in the avalanche.
The extraction of the victims stalled on Thursday due to hazardous weather conditions, the Nevada County Sheriff's Office, which is leading the search, said on Thursday.
Recovery efforts are expected to carry into the weekend. The Nevada County Sheriff's Office said on Thursday that it is unable to confirm the identifications, ages, affiliations, or cities of origin for the victims until the recovery mission is completed.
The heavy snowstorm has prevented rescuers from transporting the bodies from the backcountry to a morgue in the nearby town of Truckee, Nevada County Sheriff Shannan Moon said at a news conference on Wednesday.
Moon said the search continues for a second man from the group who is presumed dead.
Placer County Sheriff Woo has urged the public to avoid the Sierras, mountain travel and the backcountry during inclement weather over the next few days so that officials can focus on recovering the bodies.
On Thursday, the National Weather Service issued another winter weather advisory for the greater Lake Tahoe area that said another 6-12in (15-30cm) of snow is expected to accumulate in the Tahoe basin, with more at higher elevations.
Ridge winds were expected to gust as high as 45mph (72km/h) on Thursday evening, causing poor visibility and near whiteout conditions.