The backcountry ski trip organized by Blackbird Mountain Guides in California’s Sierra Nevada ended in tragedy after an avalanche struck near Castle Peak as a powerful winter storm moved into the state, authorities said. The group of 15 backcountry skiers had set out on a three-day trek organized by Blackbird Mountain Guides into remote wilderness near Frog Lake in the Tahoe National Forest. They made their way Sunday to huts at about 7,600 feet (3,415 meters), carrying their own food and supplies.
Before the group began its return plans, the Sierra Avalanche Center issued public alerts for the area. On Sunday morning at 6:49 a.m., the center issued an avalanche watch indicating large slides were likely in the next 24 to 48 hours. Around 5 a.m. Tuesday—the morning the group was scheduled to return toward the trailhead—the center increased the watch to a warning, authorities said.
Within hours, an avalanche hit near Castle Peak and trapped the skiers, the Associated Press reported. Nevada County Sheriff Shannan Moon said at a Wednesday news conference that eight people were killed and one person remained missing. Moon also said investigators were examining the decision to proceed with the trip Sunday despite forecasts of a major storm, and it was not known whether the guides would have known about the avalanche warning as they returned to the trailhead.
Search and rescue efforts unfolded under difficult weather conditions. Authorities said six skiers were rescued after sheltering in place for hours while searchers battled blizzard conditions, as the storm intensified in the region.
Blackbird Mountain Guides said in a statement Tuesday that it was coordinating with authorities and that three of its guides were among those killed. Before the disaster, the tour company said its guides were highly skilled in dealing with extreme conditions and offered avalanche education. On its website, the company advertised the “Frog Lake Huts” trip with language that it would “navigate in and out of the huts, manage the risks, and find the best terrain and snow quality” for customers, and it described the itinerary as rated for intermediate-to-expert skiers with at least 20 days of backcountry experience.
The company’s materials also said guides would carry first aid kits, while participants were required to bring their own ski equipment and avalanche gear, including a beacon, shovel and probe. The website description said participants should be adept with backcountry touring skills and have a solid foundation of touring before the trip, and it advised that guides generally find excellent backcountry snow conditions even though travel can still require moving through difficult conditions.
Avalanche experts described conditions that can make danger spike during short periods of heavy snowfall. Brandon Mathis, a Durango, Colorado backcountry skier trained in avalanche safety, said there is no single hard-and-fast rule for when avalanche risk makes a mountain too dangerous to traverse, but he said there are signs skiers should watch for. “Things get serious, needless to say, out there. So knowledge is one of your best tools for safety,” Mathis said.
Heath of snowfall and wind-driven loading were also cited by the Sierra Avalanche Center. The center said rapidly accumulating snow piling on fragile snowpack layers, along with strong winds, contributed to the treacherous conditions, according to the report. The town of Soda Springs, near where the avalanche took place, recorded at least 30 inches (76 centimeters) of snow in a 24-hour period, the report said, citing the Soda Springs Mountain Resort.
Anthony Pavlantos, owner of Utah-based Prival USA, makes avalanche safety equipment and runs mountain safety programs. He said heavy snowfall in 24 hours is a “really big red flag” and that the safest option is often to leave rather than hunker down. “High intensity snowfall in short amounts of time can increase the avalanche hazard fast,” Pavlantos said. “So, you already have a snowpack sitting on the snow and then you have all this new snow that’s falling down at a high rapid rate. That new snow can slide on that old snow surface.”