Rider triggered avalanche on Fisher mtn

Fisher Mtn.
Cooke City
Code
SS-AMu-R2-D2
Elevation
10000
Aspect
E
Latitude
45.06610
Longitude
-109.95900
Notes

From email 5/11/24: “Hey Guys, here are a few photos from the weekend.... the fisher peak avalanche happened today. Maybe cornice drop?”

From email 5/16/24: "I saw the photo of the fisher peak avalanche on the website. Figured I could fill in the blanks. Not a natural slide, snowmobile triggered.

At approximately 12:15pm last Saturday I was climbing above fisher bench and unintentionally set off a slab avalanche on fisher peak. I was jumping the cornice at the ridge and had a massive slope collapse, followed by shooting cracks and propagation downslope. I was able to wheelie through the crown and sidehill above the slide away from the debris area.

5 minutes before my climb, another snowmobiler put a high mark 60 ft away from where I climbed with no results. There were numerous tracks on the slope prior to this avalanche, I found the weak spot. My riding partner was watching me from a safe zone further south, as we knew there was new snow instabilities to watch out for, at a minimum.

We rode all day Friday without any obvious instabilities on similar slopes. We didn’t see the sheep mountain slide Friday morning. I took some pictures of the slide right after it happened. See attached…"

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Snowmobile
Trigger Modifier
u-An unintentional release
R size
2
D size
2
Problem Type
New Snow
Slab Thickness
20.0 inches
Vertical Fall
350ft
Slab Width
300.00ft
Snow Observation Source
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year