Nine backcountry skiers are dead after a massive avalanche struck near Castle Peak, just northwest of Lake Tahoe, California, on February 17, 2026. The disaster — which killed three professional guides and six clients from a group of fifteen on a guided backcountry ski trip — marks the deadliest avalanche in California’s recorded history and the deadliest in the United States in over 45 years. The group, led by Truckee-based Blackbird Mountain Guides, was on the final day of a three-day trip, returning from the Frog Lake huts to the trailhead when the slide hit at approximately 11:30 a.m. Six of the nine victims were mothers from the Bay Area, the Tahoe region, and Boise, Idaho.
Friends and family described them as close friends and “passionate, skilled skiers” — not reckless thrill-seekers, but experienced outdoorspeople who had taken the precaution of hiring professional guides. The tragedy has triggered investigations by Cal/OSHA and the Nevada County Sheriff’s Office, with a central question emerging: the Sierra Avalanche Center upgraded the avalanche danger rating to HIGH at 5:00 a.m. that morning, roughly six and a half hours before the slide. Whether the guides received and acted on that warning is now at the heart of the inquiry. This article covers what happened on Castle Peak, who the victims were, what the investigations have revealed so far, the legal and regulatory questions facing the tour operator, and what this disaster tells us about the state of backcountry skiing safety in the United States.
Table of Contents
- What Happened in the Deadliest U.S. Avalanche in Over 45 Years?
- The Critical Timeline — Did Guides Know the Danger Rating Was HIGH?
- Who Was Blackbird Mountain Guides, and What Happens Now?
- Backcountry Skiing’s Boom — and the Safety Infrastructure Struggling to Keep Up
- The Limits of Avalanche Forecasting and Personal Responsibility
- The Victims — Skilled Skiers, Not Reckless Beginners
- What Comes Next — Regulation, Litigation, and an Industry Reckoning
- Conclusion
- Frequently Asked Questions
What Happened in the Deadliest U.S. Avalanche in Over 45 Years?
The avalanche struck on Tuesday, February 17, 2026, on the slopes near Castle Peak in the Sierra Nevada. A group of fifteen skiers — eleven clients and four guides employed by Blackbird Mountain Guides, LLC — had spent two nights at the Frog Lake huts and were making their way back to the trailhead when the mountainside gave way. Of the fifteen people caught in the slide’s path, six survived and were rescued. Nine did not. The three guides killed were andrew Alissandratos, 34, of Verdi, Nevada; Michael Henry, 30, of Soda Springs, California; and Nicole Choo, 42, of South Lake Tahoe, California. The six clients who died were Carrie Atkin, 46, of Soda Springs; Lizabeth Clabaugh, 52, of Boise, Idaho; Danielle Keatley, 44, of Soda Springs and Larkspur, California; Kate Morse, 45, of Soda Springs and Tiburon, California; Caroline Sekar, 45, of Soda Springs and San Francisco; and Katherine Vitt, 43, of Greenbrae, California.
All nine victims were identified by the Nevada County Sheriff’s Office after a grueling five-day search-and-recovery operation that was complicated by continued intense winter storms. The last of the nine bodies was recovered by February 21, 2026. To put the scale of this disaster in context, the last U.S. avalanche with a comparable death toll occurred more than four decades ago. The deadliest avalanche in American history took place on March 1, 1910, near Stevens Pass in Wellington, Washington, when a massive wall of snow swept two stranded Great Northern Railway trains off the tracks and into a canyon, killing 96 people. Nothing in the modern backcountry skiing era has come close to what happened at Castle Peak.
The Critical Timeline — Did Guides Know the Danger Rating Was HIGH?
The central question now facing investigators is whether the Blackbird Mountain Guides team was aware of the escalating avalanche danger before they set out on the morning of February 17. The Sierra Avalanche Center had issued an avalanche watch on Sunday, February 15 — two days before the slide — putting backcountry users on notice that conditions were deteriorating. On the morning of the disaster itself, an avalanche warning was posted, and the center upgraded its danger rating to HIGH at 5:00 a.m., roughly six and a half hours before the slide struck. Whether the guides checked the forecast that morning, whether they had cell service at the Frog Lake huts to receive the updated rating, and whether a HIGH rating should have prompted them to alter their route or shelter in place are questions the Nevada County Sheriff’s Office is now examining.
In professional guiding, checking the morning avalanche advisory is considered a baseline safety practice — not optional, not aspirational, but fundamental. A HIGH danger rating on a day when the group’s planned activity involved traversing avalanche-prone terrain should, under standard guiding protocols, trigger a serious reassessment of travel plans. However, it is important to note that a HIGH danger rating does not mean all backcountry travel is impossible. It means that natural and human-triggered avalanches are very likely, and that travel in avalanche terrain demands extreme caution, conservative route selection, and in many cases, a decision not to go at all. The investigation will need to determine whether the guides made a defensible decision given the information available to them at the time — or whether the warning signs were missed or ignored.
Who Was Blackbird Mountain Guides, and What Happens Now?
Blackbird Mountain Guides, LLC, is an outdoor tour company based in Truckee, California, that offered guided backcountry skiing trips in the Sierra Nevada. The company operated the three-day Frog Lake hut trip that ended in catastrophe. Cal/OSHA has opened a formal workplace safety investigation into Blackbird, which is standard procedure when employees — in this case, three guides — die in the course of their work. The Cal/OSHA investigation will examine whether the company had adequate safety protocols in place, whether its guides were properly trained and certified, whether the company’s procedures required guides to check avalanche forecasts before departing on trips, and whether any workplace safety standards were violated.
Cal/OSHA has the authority to issue citations and fines, and its findings could have implications for how guided backcountry operations are regulated in California going forward. Separately, the Nevada County Sheriff’s Office investigation is examining the broader decision-making before and during the trip. This is a fact-finding inquiry, not a criminal investigation at this stage, but its conclusions could influence whether any legal action follows. For the families of the victims, the findings of both investigations will likely shape whether civil litigation is pursued against Blackbird Mountain Guides. Guided backcountry skiing trips typically require clients to sign liability waivers, but such waivers do not necessarily shield operators from claims of gross negligence — particularly if evidence shows that guides failed to heed clear and publicly available danger warnings.
Backcountry Skiing’s Boom — and the Safety Infrastructure Struggling to Keep Up
The Castle Peak disaster did not happen in a vacuum. Backcountry skiing has experienced an enormous surge in popularity over the past decade, accelerated by the COVID-19 pandemic when resort closures and lift-line restrictions pushed skiers into the backcountry in record numbers. Many of those skiers stayed. The result has been a significant increase in the number of people traveling in avalanche terrain, often without the training, experience, or equipment to manage the risks involved. Guided backcountry trips were supposed to be the safer alternative — a way for experienced recreational skiers to access challenging terrain with the benefit of professional risk management.
The Castle Peak tragedy complicates that narrative. When three out of four guides on a trip are killed alongside six of their eleven clients, it raises hard questions not just about one company’s practices, but about the adequacy of the standards, certifications, and regulatory oversight that govern the guided backcountry industry in the United States. Compare this to helicopter skiing operations in Canada, where operators are subject to rigorous government oversight, mandatory guide certification through the Association of Canadian Mountain Guides, and industry-wide safety protocols that include strict rules about avalanche forecast thresholds. The U.S. backcountry guiding industry operates with considerably less regulatory structure. Whether that changes in the wake of Castle Peak remains to be seen, but the conversation has already begun.
The Limits of Avalanche Forecasting and Personal Responsibility
One of the harder truths exposed by the Castle Peak avalanche is that avalanche forecasting, while vastly improved over the past several decades, is not a guarantee of safety. The Sierra Avalanche Center issued clear warnings — an avalanche watch on February 15, a warning and a HIGH danger rating on the morning of February 17. These tools exist precisely to prevent disasters like this one. But they only work if the people making decisions in the field receive them, understand them, and act on them. Even when forecasts are perfect, avalanches are inherently unpredictable at the scale of individual slopes. A forecast can tell you that conditions are dangerous across a region.
It cannot tell you which specific slope will slide, or when. This is why backcountry travel in HIGH danger conditions is not simply a matter of picking a “safer” route — it is a matter of accepting that the margin for error has shrunk to nearly nothing, and that the consequences of a wrong call are catastrophic. For recreational backcountry skiers who travel without guides, the Castle Peak disaster is a stark reminder that hiring a guide does not eliminate risk. It transfers the decision-making to someone with more training and experience, but the mountain does not care about credentials. Anyone entering avalanche terrain — guided or not — should understand the rating system, carry rescue equipment (beacon, shovel, probe), practice using it regularly, and be willing to turn around when conditions deteriorate. The hardest skill in backcountry skiing is not skiing. It is saying no.
The Victims — Skilled Skiers, Not Reckless Beginners
It is worth pausing on who these nine people were, because the reflexive public reaction to avalanche deaths often involves some version of “they should have known better.” These were not reckless beginners. Six of the nine victims were mothers — women with families, careers, deep ties to their communities in the Bay Area, the Tahoe region, and Boise. Friends described them as close-knit, passionate, and skilled. They hired professional guides. They carried avalanche safety equipment.
They did what they were supposed to do. The three guides — Alissandratos, Henry, and Choo — were professionals who had made backcountry skiing their careers. Their deaths underscore that expertise and experience, while essential, are not immunity. The mountain is indifferent to your resume. What happened at Castle Peak was not a failure of individual judgment by the skiers who signed up for the trip. Whether it was a failure of professional judgment by the guides, or a failure of systems and protocols, is what the investigations will determine.
What Comes Next — Regulation, Litigation, and an Industry Reckoning
The aftermath of the Castle Peak avalanche is likely to play out on several fronts simultaneously. The Cal/OSHA and Nevada County Sheriff’s Office investigations will establish the factual record. Civil litigation from the families of the victims seems probable, particularly if the investigations reveal that the guides did not check or did not act on the morning’s HIGH danger rating.
And the broader backcountry guiding industry will face renewed pressure to adopt — or be subjected to — more rigorous safety standards and regulatory oversight. Whether this disaster becomes a turning point for backcountry safety regulation in the United States depends on what the investigations find and whether there is political will to act on the findings. The Stevens Pass disaster of 1910 led to the construction of the Cascade Tunnel, fundamentally changing how railroads managed avalanche risk. The question now is whether the Castle Peak disaster of 2026 will produce a comparable shift in how the backcountry skiing industry manages the risks it sells to its clients — or whether the moment will pass, the news cycle will move on, and the next group of skiers will head into the mountains under the same regulatory framework that failed to prevent this one.
Conclusion
The Castle Peak avalanche of February 17, 2026, killed nine people — three guides and six clients — making it the deadliest avalanche in California’s history and the worst in the United States in more than 45 years. The victims were experienced, well-equipped skiers on a professionally guided trip. They did the things you are supposed to do to manage backcountry risk, and they died anyway. The investigations now underway will determine whether their deaths were the result of an unforeseeable natural disaster or preventable failures in professional judgment and institutional oversight. For anyone who ventures into avalanche terrain — or who is considering hiring a guide to do so — the lessons of Castle Peak are uncomfortable but essential.
Check the forecast. Understand what the danger ratings mean. Carry rescue equipment and know how to use it. Ask your guide what their decision-making protocol is when the danger rating is HIGH. And understand that in the backcountry, there is no such thing as zero risk. There is only the relentless, honest management of risk — and the willingness to turn around when the mountain says no.
Frequently Asked Questions
What was the Castle Peak avalanche?
On February 17, 2026, an avalanche struck near Castle Peak, northwest of Lake Tahoe, California, killing nine backcountry skiers — three professional guides and six clients — from a group of fifteen on a guided trip operated by Blackbird Mountain Guides. It was the deadliest avalanche in the United States in over 45 years.
Who were the victims of the Castle Peak avalanche?
The three guides killed were Andrew Alissandratos (34), Michael Henry (30), and Nicole Choo (42). The six clients killed were Carrie Atkin (46), Lizabeth Clabaugh (52), Danielle Keatley (44), Kate Morse (45), Caroline Sekar (45), and Katherine Vitt (43). Six of the nine victims were mothers from the Bay Area, the Tahoe region, and Boise, Idaho.
What caused the Castle Peak avalanche?
The avalanche struck during a period of intense winter storms. The Sierra Avalanche Center had issued an avalanche watch on February 15 and upgraded the danger rating to HIGH at 5:00 a.m. on February 17, approximately six and a half hours before the slide. Investigations are examining whether the guides received and acted on these warnings.
Who is investigating the Castle Peak avalanche?
Two investigations are underway. Cal/OSHA has opened a workplace safety investigation into Blackbird Mountain Guides, LLC, the Truckee-based company that organized the trip. The Nevada County Sheriff’s Office is separately examining the decision-making before and during the trip.
What was the deadliest avalanche in U.S. history?
The deadliest avalanche in U.S. history occurred on March 1, 1910, near Stevens Pass in Wellington, Washington, when a massive snow slide struck two stranded trains, killing 96 people. The Castle Peak avalanche is the deadliest in the U.S. in the modern backcountry skiing era.
Can you still sue a backcountry guide company if you signed a liability waiver?
Liability waivers are common in guided backcountry trips, but they do not necessarily protect operators from claims of gross negligence. If investigations show that guides failed to heed publicly available avalanche danger warnings, the waivers may not shield the company from civil liability. The outcome of the current investigations will likely influence any legal action by victims’ families.