Overview
The mountain sits on an active volcano. Not a metaphor. Mammoth is part of the Long Valley Caldera, and it vents 50-150 tons of carbon dioxide daily through cracks in the rock. In 2006, three patrollers fell into one of these vents and suffocated.
2006 was the worst year: eight dead, including that volcanic incident and a run of four skier deaths in four days. The 2025-26 season is shaping up badly too. Four deaths so far, two of them patrollers killed in avalanches ten months apart, in nearly the same spot.
What happened
The fumarole collapse
The 2005-06 season dumped 52 feet of snow on Mammoth. Somewhere beneath all that white, volcanic vents kept pumping out CO₂, melting caverns into the snowpack from below.
Four patrollers were reinforcing a fence around a known fumarole on the Christmas Bowl run when the snow bridge collapsed. Two fell 21 feet (6.4 m) into a cavity with CO₂ concentrations between 20-90%. Both died on impact. A third patroller survived the fall but his oxygen mask failed to seal properly during rescue attempts. He died from carbon dioxide and hydrogen sulfide exposure. Seven others were injured in the rescue effort.
The avalanche chutes
Same chutes. Same job. Ten months apart. Both patrollers were doing avalanche mitigation on Lincoln Mountain when they got caught in slides.
Claire Murphy, 25, was caught on February 14, 2025 during Presidents Day weekend prep. Wind was howling "like a jet engine" according to witnesses. Her partner triggered the slide with his skis and was buried to the neck but survived. Claire was swept into a fir tree — trapped upright, back against the trunk, facing uphill toward the wall of snow. She died on scene.
Her mother Lisa Apa told the LA Times she begged Mammoth to review their procedures. When Cole Murphy died ten months later, she texted a ski patrol manager: "You killed another ski patroller... you've learned nothing."
Cole Murphy, 30 (no relation), was caught on December 26 during post-Christmas mitigation. An avalanche from a neighboring chute may have propagated horizontally to where he was working. He was buried under approximately one meter of debris for 18 minutes. When rescuers extracted him, his skin was blue and he wasn't breathing. Airlifted to Renown Regional Medical Center in Reno; pronounced dead December 28.
Four days in January
In a normal season, Mammoth sees about three deaths total. In late January 2006, four people died in four days. None of the deaths were related to each other.
January 26: 16-year-old boy from San Diego died after taking a jump too fast on an intermediate run and missing the landing. He was wearing a helmet and reportedly experienced. January 27: 39-year-old man from Laguna Niguel lost control at high speed on an intermediate trail, struck a tree after hitting a mogul. Died four days later at Renown Regional Medical Center. January 28: 61-year-old Los Angeles dentist became disoriented in windy, snowy conditions that had closed some lifts. Collided at full speed with a 30-foot boulder in a canyon area. January 29: 63-year-old man from Garden Grove suffered a fatal heart attack while skiing.
Everyone
The resort opened in 1955, but records from before 1973 aren't digitized. This timeline starts with the first documented fatality.
Unidentified skier
Fell on Dropout 2, slid headfirst for hundreds of yards. Witnesses watched from Chair 23.
Snowboarder (beginner)
Died of apparent head injury. Was wearing a helmet.
Cole Murphy, 30 Patrol
Buried 18+ minutes during avalanche mitigation. Died December 28 at Reno hospital.
Raymond Albert, 71 "Every Day Ray"
Found head-down in deep powder after Christmas storm. CPR unsuccessful.
Claire Murphy, 25 Patrol
Caught in avalanche during mitigation work. Crushed against a fir tree.
McAnally, Juarez, Rosenthal Patrol
Three patrollers killed in fumarole collapse. Fell 21 feet into CO₂-filled cavity.
31-year-old woman Patrol (off-duty)
Caught in avalanche near Twin Lakes. Broken back and leg.
63-year-old man (Garden Grove)
Fatal heart attack while skiing.
61-year-old dentist (Los Angeles)
Collided with 30-foot boulder in whiteout conditions.
39-year-old man (Laguna Niguel)
Lost control, struck tree after hitting mogul. Died four days later.
16-year-old boy (San Diego)
Missed jump landing on intermediate run. Was wearing a helmet.
About the mountain
- Location
- Mammoth Lakes, California · Eastern Sierra Nevada
- Summit Elevation
- 11,053 feet (3,369 m)
- Skiable Terrain
- 3,500 acres with 3,100 ft vertical drop
- Annual Snowfall
- 400 inches average
- Owner
- Alterra Mountain Company (since 2017)
- Geological Note
- Located on an active volcanic system (Long Valley Caldera). The mountain emits 50-150 tons of CO₂ daily.