How common are fatal avalanches? Castle Peak snowslide deadliest in California

An avalanche near Castle Peak on Tuesday swept away 15 people, leaving eight dead and one missing.

It’s the deadliest avalanche on record in California according to data going back to 1951 kept by the Colorado Avalanche Information Center.

And it’s the deadliest in U.S. in the last 40 years, following a slide on Mount Rainier that killed 11 people in 1981.

Search and rescue crews had successfully rescued six survivors Tuesday night in the backcountry near Truckee. The search continued for the nine others still missing around 11:30 a.m., according to search and rescuers led by the Nevada County Sheriff’s Office.

In a news conference, the Sheriff’s Office announced eight of the missing were found dead. One remains unaccounted for.

The avalanche came during a fierce winter storm that dumped heavy snowfall on the Sierra Nevada.

But it’s far from the first fatal avalanche in California history, or even in this season. Here’s what to know:

Have there been other fatal avalanches in the area?

The latest avalanche came about six weeks after a separate, fatal slide on the backside of Castle Peak claimed the life of a 42-year-old man.

Chris Scott Thomason of Bend, Oregon, was killed Jan. 5 when an avalanche was triggered as he and four companions were snowmobiling in the area.

The group had set out from the Johnson Canyon area and successfully reached Castle Peak before the avalanche occurred on their return trip, authorities said at the time.

Thomason was buried in the snow and located by his partners using avalanche beacons. They began CPR, assisted by an off-duty Truckee Fire medic who came upon the scene, but he did not survive.

Three other fatal slides have happened close to Castle Peak since 2012.

Castle Peak sits just north of Soda Springs on the north side of Lake Tahoe and is a popular destination for backcountry recreation, with terrain ranging from lower-angle slopes to steeper runs.

Where have other fatal snowslides happened in California?

California has averaged one avalanche fatality per year, according to the Colorado Avalanche Information Center data. But despite how fairly uncommon deaths are, the state has a history of snowslide tragedies.

The area surrounding Alpine Meadows has the dubious distinction of the largest number of fatalities since 1951, according to the Colorado Avalanche Information Center. Seven people were killed in March 1982 after a massive avalanche crashed into the base area of the ski resort, Outside Magazine said.

The area also recorded a total of five fatalities in avalanches in 1976, 1990 and most recently in 2013.

Squaw Valley and the surrounding area and Mount Baldy have each recorded five fatalities since 1951, according to the Colorado Avalanche Information Center.

At least six people in the U.S. have died in avalanches this season as of Wednesday, according to the Colorado Avalanche Information Center. That includes two in California: the snowmobiler who was killed near Castle Peak on Jan. 5 and a ski patroller killed near Mammoth Lakes on Dec. 26.

Is backcountry skiing dangerous?

The 15 people caught up in an avalanche Tuesday were reportedly on a guided backcountry skiing trip.

Backcountry skiing or snowboarding involves skiing on ungroomed snow in sparsely populated areas generally outside ski resorts, WildsNow said.

“Regardless of whether you hike, snowshoe, skin, ride a lift or take a helicopter to get there, any time you’re outside of the maintained and controlled boundaries of a resort, you’re in the backcountry,” REI said.

Thirteen backcountry skiers have died in California avalanches since 1979, most recently in February 2025, when a skier was killed at Powderhouse Peak south of Lake Tahoe, data from the Colorado Avalanche Information Center shows.

REI advised backcountry skiers to be aware of avalanche conditions, assess fitness levels, carry proper safety gear and plan ahead.

What to know about avalanches

Avalanches happen quickly and catch people by surprise. They can move between 60 and 80 mph and typically happen on slopes of 30-45 degrees, according to experts.

Skiers, snowmobilers and hikers can set off an avalanche when a layer of snow collapses and starts to slide down the slope.

In the U.S., avalanches are most common from December to April, but they can happen at any time if the conditions are right, National Geographic reported.

People heading into snow should always check the local avalanche forecast at Avalanche.org, officials with the U.S. Department of Agriculture said, and have an avalanche beacon, probe and shovel ready.

“Emergency services are usually too far away from the scene of an avalanche, and time is important,” Simon Trautman, a national avalanche specialist, said. “A person trapped under the snow may not have more than 20 or 30 minutes. So, in a backcountry scenario, you are your own rescue party.”

If an avalanche breaks out, it’s best to move diagonal to the avalanche to an edge, Trautman said.

“Try to orient your feet downhill so that your lower body, not your head, takes most of the impact,” officials said. “You may also get into a tight ball as another way to protect your head.”

The Bee’s Daniel Hunt contributed to this story.

This story was originally published February 18, 2026 at 11:52 AM with the headline "How common are fatal avalanches? Castle Peak snowslide deadliest in California."