COOKE CITY — According to the Gallatin National Forest Avalanch Center, a snowmobiler was killed Saturday, Dec. 31, 2022, in a very large avalanche north of Cooke City.
(Note, the original story posted contained the wrong date, the incident occurred on Dec. 31, 2022, not Jan. 31, 2022. Article has been updated with correct date)
The avalanche occurred on a southeast-facing slope at 9,800’. Two riders were snowmobiling uphill on adjacent slopes. One was climbing a steeper slope and triggered the avalanche 100-200’ below the top. He was carried 600 vertical feet and buried 5 feet deep. The buried rider was wearing an airbag pack that was not deployed. Both riders had shovels and probes. They were not wearing avalanche beacons.
A nearby group of riders rode up to the slide within minutes after it happened, saw a buried snowmobile and began to search for the buried rider. One rider from that group went into Cooke City to alert Search and Rescue. The buried rider was located with a probe line an hour after the avalanche happened. He was unable to be revived with CPR and AED at the site.
The avalanche appeared to be 2-4' deep, 500' wide, ran 600' vertical, and broke on weak snow near the bottom of the snowpack.
In a social media post, officials said this fatality is the clearest possible indicator that the snowpack remains capable of producing large and dangerous avalanches.
"Slides can break on weak layers in the lower snowpack, within the snow that’s fallen over the last week (particularly where it has been wind drifted) or on a weak layer buried just beneath it. Continued patience (avoiding avalanche terrain) and adherence to safe travel protocols (riding one at a time, carrying rescue gear, and watching your partners for a safe spot) are the best ways to manage these concerns. MODERATE danger across the region."
This is a developing story and will be updated as more information becomes available.
Photo: Snowmobile triggered avalanche along Lionhead ridge. 12/31/22. T. Anafarta photo.