Large recent avalanches near Cooke City

Large recent avalanches near Cooke City

Date
Activity
Snowmobiling

Today we rode north of Cooke City and looked at recent natural and Human-triggered avalanches. The slide on Fisher Mtn. was very large and appeared up to 10 feet deep. It had much more volume in the debris than the slide that was triggered on this same path in December.

We also looked at the slide on Crown Butte that was triggered by a snowmobiler yesterday. This was on a SW aspect at 9,600'. It was 1-3 feet deep and broke on a layer of surface hoar and large facets below a hard slab of wind-drifted snow. 

We saw two slides that had not been reported previously. One natural on the east side of Sheep Mtn. that was a hard slab of wind-drifted snow on a heavily wind loaded slope near the high ridgeline at 10,500'. The second was snowmobile triggered on a path called "Marty's" above Daisy Pass road. This was similar aspect as the slide on Crown Butte yesterday, and likely had a similar snowpack structure. We checked the debris for a beacon signal to be sure no one was caught, and did not find one. This may have been triggered today (3/12).

This recent activity is a clear sign the snowpack remained unstable with the recent loading event. Due to these slides breaking on persistent weak layers, I think similar human-triggered avalanches remain likely.

Region
Cooke City
Location (from list)
COOKE CITY
Observer Name
Alex Marienthal