Crown Butte Avalanche Fatality Accident Report

Activity
Snowmobiling
Date
1 snowmobiler caught, buried and killed
Synopsis

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On December 31, 2022 a snowmobiler was killed in a very large avalanche north of Cooke City, MT near Daisy Pass on a southeast facing slope of Crown Butte at 9,800’. Two brothers (ages 17 and 21) from Washington state were snowmobiling uphill on adjacent slopes. The older brother was climbing a steeper slope and triggered the avalanche 200’ below the top. He was carried and buried 5 feet deep near the toe of the debris which measured 10-15 feet deep. He was wearing an airbag pack that he did not deploy. Both riders had shovels and probes, but no avalanche beacons. A nearby group was gathered at the bottom of the slope when the slide happened. They noticed the powder cloud, turned around and saw a buried snowmobile and began to search. One rider went into Cooke City to alert Search and Rescue. Searchers located the buried rider with a probe line. He was extricated an hour after the avalanche happened, but resuscitation efforts were unsuccessful. The avalanche was 500 feet wide, 1.5-2 feet deep on average, 4 feet at the deepest and ran 600 vertical feet with a runout angle of 25 degrees. The avalanche is classified HS-AMu-R4-D3-O.