Scotch Bonnet peak MT 2 snowmobile fatalities.

https://mtavalanche.com/node/25278

Scotch Bonnet
Cooke City
12/27/2021
Code
AMu
Elevation
9900
Aspect
SE
Latitude
45.05660
Longitude
-109.95100
Notes

We are sad to report that yesterday, December 27th, two snowmobilers were caught and killed in an avalanche on Scotch Bonnet Mountain to the north of Cooke City. At the time of the avalanche, four riders were on the slope. Two were able to escape. All eight members of the group had rescue equipment. The avalanche broke 5’ deep and approximately 300’ wide on a southeast-facing slope.

Members of Park County Sheriff Search and Rescue arrived to assist with rescue and recovery efforts.

Our deepest condolences go out to the victim’s friends and family, members of the group and the search and rescue community. We will release further details as they become available.

Of note: a fair amount of trees in the start zone...tree were not good anchors in this case.

Attachment 398556

In my experiences that amount of vegetation creates deficit zones.

Quote:

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Originally Posted by Bunion 2020

Attachment 398556

In my experiences that amount of vegetation creates deficit zones.

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Makes sense yes. I've seen too many videos of slides in trees to view them as a "safer" place to be.

https://youtu.be/HRVGmkJnIog

Deficit zones? Like a thin snowpack w/ trigger points?

Sounds like it was triggered from below and broke on the rocks and krummholz near the ridge line.

Wonder if the continued snowmobile traffic in the area made the reporter nervous


Sent from my iPhone using TGR Forums

Quote:

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Originally Posted by NWFlow

Deficit zones? Like a thin snowpack w/ trigger points?

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areas of less than average stability. But often what you just described. I think of them (and specifically the zone pictured) as areas with spatial variability

Potato/Tomato......

Specifically in a continental/transitional snow pack all areas covered in snow will have some to a lot of spatial variability.

Those krummholz areas in my experience at/around treeline allow a higher level of temp. gradient and vapor transfer and a thin snowpack w/ trigger points or areas of less than average stability?

I don't follow the Cooke City snow pack that closely but my impression prior to Christmas was that there was a relatively stable snow structure for Montana but they were also getting a lot of snow and wind prior to the accident and putting 4 sleds and riders on that slope was more than it could support.

I ride and ski in Cooke all the time. We ski across the valley from Scotch on the N facing slopes all the time. People die on those south facing chutes every year. There is a reason those are always untracked while everything else is tracked up. I have stopped people from riding up those chutes quite a few times in my life. I stop and give people eyeing it up a quick 101 about those specific chutes and to find another place to ride avoiding south facing, wind loaded areas. 3-4 years ago I kept a group off it. Two days later when I got home one person was killed there again.

They had transceivers, but basic mountain knowledge is just as or more important. Reading the avy reports every day in areas you ride even if you are not there keeps you in the loop about persistent / problematic layers (which there has been all year in Cooke). Every skier and snowmobiler should take a level 1 avy course. It opens your eyes and dramatically improves your decision making in the back country.