{"id":10083,"date":"2026-04-03T23:08:19","date_gmt":"2026-04-03T23:08:19","guid":{"rendered":"https:\/\/wildgreenquest.com\/?p=10083"},"modified":"2026-04-03T23:08:19","modified_gmt":"2026-04-03T23:08:19","slug":"why-was-the-tahoe-avalanche-so-deadly","status":"publish","type":"post","link":"https:\/\/wildgreenquest.com\/?p=10083","title":{"rendered":"Why Was the Tahoe Avalanche So Deadly?"},"content":{"rendered":"


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Published April 3, 2026 04:34PM<\/p>\n<\/div>\n

Almost two months after a deadly Tahoe avalanche killed nine people in California on February 17, avalanche experts have published an official incident report on the tragedy. According to an analysis<\/a> by the National Avalanche Center and the Colorado Avalanche Information Center, a wide range of factors\u2014from weather to slope angle\u2014contributed to the disaster. But perhaps most crucial was the decision by guides to have all 15 members of the party travel together amid worsening avalanche conditions.<\/p>\n

\u201cExposing only one person at a time to avalanche terrain is an accepted best practice for backcountry travel,\u201d the report notes. \u201cThis group consisted of 15 people. Analysis of past avalanche accidents has indicated that larger group sizes (four or more people) have a higher chance of being caught in avalanches.\u201d<\/p>\n

Rick Rogers was a member of the San Bernardino County Sheriff\u2019s Search and Rescue team in California for 11 years. He also worked as a ski patroller for Heavenly Ski Resort in Tahoe from 2010 until his retirement in 2023. He\u2019s familiar with the area where the deadly avalanche occurred.<\/p>\n

\u201cNot being privy to the decision-making process, the only way to mitigate this accident 100 percent would have been to stay in the huts and ride out the storm,\u201d Rogers told Outside<\/em>.<\/p>\n

(Left) Looking down from the likely starting zone of the avalanche. (Right) Looking up from the <\/span> (Photo: American Avalanche Association)<\/figcaption><\/figure>\n

The 30-Degree Danger Zone<\/h2>\n

According to the report, the group \u201ctraveled below avalanche terrain and through the runout zone of an avalanche path during a period when a natural or human-triggered avalanche was likely to very likely.\u201d The area recorded 111 inches of snowfall during the storm between February 15 and 19, the report stated, adding to an already precarious snowpack<\/a>.<\/p>\n

Rogers told Outside<\/em> that he was also confused by the group\u2019s decision to travel together amid the worsening avalanche conditions.<\/p>\n

\u201cMy question is whether this group knew they were underneath the avalanche terrain during the storm. When you\u2019re traveling through known avalanche terrain like that, it\u2019s best to travel one person at a time or to stay put,\u201d he said. \u201cI was in the area for the storm, and it was dumping.\u201d<\/p>\n

When touring the backcountry, several factors make certain terrain more prone to avalanches, one being the angle of the slope. According to a report<\/a> published by the Sierra Avalanche Center, the avalanche likely started on a slope with an angle between 36 and 40 degrees. The burial site was located on a slope with a gradient of 22 to 25 degrees.<\/p>\n

\u201cAround 30-degree slopes are where avalanches tend to happen,\u201d Rogers explained. \u201cAny steeper, the snow tends to slough off during the storms. Less of an angle, the snow doesn\u2019t run off.\u201d<\/p>\n

The report also notes that the group consisted of 15 people. Analysis of past avalanche accidents has indicated that groups of four or more people are more likely to be caught in avalanches. Larger groups tend to have a heightened risk tolerance, greater difficulty communicating, and a greater impact on the snowpack, according to the American Avalanche Association<\/a>.<\/p>\n

Another backcountry avalanche consideration is anchors\u2014trees, rocks, or other features that can help stabilize the snowpack. Typically, it\u2019s safer to ski in areas with more anchors when the snowpack is unstable. A satellite image of the avalanche area, however, showed its path cut through a well-established slide area, where there were few anchors for snow.<\/p>\n

\"A
A satellite image shows where the fatal avalanche occurred, outlined in red<\/span> (Photo: American Avalanche Association)<\/figcaption><\/figure>\n

The Dangerous Physics of Wind-Loaded Slab<\/h2>\n

Officials measured wind gusts over 125 miles per hour in some areas near where the slide occurred, which Rogers says isn\u2019t uncommon for major Pacific storms that roll through the area. What\u2019s more important is how and where these high winds deposit snow.<\/p>\n

\u201cThe wind contributes a lot to the creation of avalanches because it transports snow,\u201d Rogers said.<\/p>\n

Wind deposits snow on the leeward, or downwind, side of a ridgeline as it blows over. Wind also packs snow down. In the Sierra Avalanche Center\u2019s report, the snow was described as a soft slab, meaning it moved as a single, cohesive chunk.<\/p>\n

\u201cAs the air is flowing up and over the ridgeline, it swirls and deposits snow on the other side of the ridge. As you look at the ridgeline, one side may be scoured and rocky while the other side can have several feet of snow,\u201d Rogers said.<\/p>\n

According to the report, the group was skiing below that leeward slab of snow. Poor visibility would have made it difficult to see the snowpack, determine the slope angle, and spot anchors, the report said.<\/p>\n

\"This
This is the slope where the avalanche occurred, taken three days later. By that time, the storm had covered up any signs of the avalanche or its debris.<\/span> (Photo: American Avalanche Association)<\/figcaption><\/figure>\n

Sierra Cement and the Science of Snowpack<\/h2>\n

Because the Sierra Nevada mountain range is so close to the ocean, snow tends to have a high moisture content\u2014sometimes called the snow water equivalent<\/a>\u2014making it particularly heavy. Snow water equivalent represents the depth of water that would result if the snowpack melted and serves as an important metric for forecasting avalanche danger. On the day of the avalanche, the SWE was 2.7 inches, indicating a very dense layer of snowfall.<\/p>\n

\u201cWe refer to it as \u2018Sierra Cement,\u2019\u201d Rogers said. \u201cThe more water, the heavier the snow, the more likely it is to slide.\u201d<\/p>\n

The avalanche report also noted a layer of facets, two to four inches thick. Facets are crystals that form in the snowpack when snow repeatedly melts, refreezes, and becomes buried. These layers can create unstable conditions, and if buried beneath a slab, they can trigger a snow slide.<\/p>\n

\u201cIn this instance, there was a facet layer, which is a weak layer in the snowpack, then a rain crust, then four to six inches of new snow, and then we got a big storm,\u201d Rogers said. \u201cThere was a lot of snow lying on top of a weak layer.\u201d<\/p>\n