Sierra avalanche kills snowmobiler, identified as 42-year-old from Oregon
At least one person died Monday after an avalanche struck a popular snowmobiling area near Castle Peak in Nevada County, prompting a large emergency response to look for more trapped in the snow.
About 45 first responders — including Nevada County sheriff’s deputies, search and rescue teams and fire agencies from the surrounding area — were dispatched after a 911 call reported a snowmobiler missing in the backcountry near Truckee. The call was transferred from Washoe County, Nevada, to the Nevada County Regional Dispatch Center at 2:19 p.m., the Nevada County Sheriff’s Office said in a statement.
“As events unfolded, it was learned the one snowmobiler initially reported missing was found buried under the snow several minutes later,” the Sheriff’s Office said. “He was recovered by fellow recreationists and despite lifesaving efforts, he did not survive.”
The victim was identified as Chris Scott Thomason, 42, of Bend, Oregon, according to the Nevada County Sheriff’s Office.
Authorities confirmed Tuesday that all others known to be in the area had been accounted for and were safe. The incident began when five experienced snowmobilers left the Johnson Canyon area and successfully reached Castle Peak. On their return, an avalanche was triggered on the backside of the mountain, burying one rider.
Thomason’s companions, who were equipped with avalanche beacons and certified at performing cardiopulmonary resuscitation, quickly located and dug him out. CPR was initiated immediately by the snowmobilers, according to the Sheriff’s Office.
“After successfully retrieving him and beginning CPR, another group of three individuals, not affiliated with the group, came across the scene,” the Sheriff’s Office said in a statement. “One of these individuals happened to be an off-duty Truckee Fire medic who immediately began leading emergency efforts and CPR.
“Despite the group taking several safety precautions and Thomason receiving high-level CPR, he sadly did not survive the incident.”
The incident marked the second fatal avalanche in the Sierra Nevada region in less than 10 days.
On Dec. 26, two ski patrollers at Mammoth Mountain were caught in an avalanche while conducting avalanche mitigation work before the resort opened. Both were rescued and hospitalized, but one of them — 30-year-old Cole Murphy — later died of his injuries, the resort announced.
The latest avalanche followed a storm system that dropped more than 40 inches of snow in a seven-day period at the nearby UC Berkeley Central Sierra Snow Lab, officials there said Monday morning. Half of that fresh snow fell in the 24 hours ending 10 a.m., the lab said.
While the snow has been a boost for a ski season that began with below-average snow levels, the wave of storms to pound the Sierra have heightened avalanche danger coming off the holidays, typically the busiest time for ski resorts statewide.
On Monday morning, the Sierra Avalanche Center reported that the recent storm was beginning to wind down, but warned that avalanche risks remained elevated due to strong winds and unstable snow.
“Unstable snow is expected in areas where slabs of wind-drifted snow have formed, along with dry loose sluffs in more wind-protected terrain,” the center said in its daily advisory. “Recreating on lower-angle slopes out of the wind can help reduce the risk of being caught in an avalanche today.”
The terrain near Castle Peak was listed under a “considerable” avalanche danger on Monday. The risk was expected to drop to “moderate” by Tuesday.
The Nevada County sheriff’s Search and Rescue team had been working on a separate missing person case in Placer County but were redirected to the avalanche, about 10 miles west of Truckee. Tahoe Nordic Search and Rescue also responded. Crews deployed three SnoCats, three snowmobile teams and several ski teams to reach the scene, according to the Sheriff’s Office.
The search party wrapped up late last night, deputies said, after accounting for all individuals known to be in the area.
“The Sheriff’s Office extends its sincere condolences to the family and loved ones impacted by this tragic incident,” deputies said.
This story was originally published January 5, 2026 at 8:09 PM.
