Snowmobiler avalanche fatality on Crown Butte

Crown Butte
Cooke City
Code
HS-AMu-R4-D3-O
Elevation
9800
Aspect
SE
Latitude
45.05250
Longitude
-109.96200
Notes

On December 31, 2022 a snowmobiler was killed in a very large avalanche north of Cooke City, MT. The avalanche occurred near Daisy Pass on Crown Butte on a southeast facing slope at 9,800’. Two brothers (age 17 and 21) from Washington were snowmobiling uphill on adjacent slopes. The older brother 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 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, 600' vertical, and broke on weak snow near the bottom of the snowpack. AMu-HS-R3/4-D3-O

Our deepest condolences go out to the family, friends, and those involved.  

Full report available here: http://www.mtavalanche.com/accident/22/12/31

 

Number of slides
1
Number caught
1
Number buried
1
Number killed
1
Avalanche Type
Hard slab avalanche
Trigger
Snowmobile
Trigger Modifier
u-An unintentional release
R size
4
D size
3
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness
24.0 inches
Vertical Fall
600ft
Slab Width
500.00ft
Weak Layer Grain type
Faceted Crystals
Weak Layer grain size
1.50mm
Weak Layer Hardness
4F
Slab Layer Grain Type
Decomposing and Fragmented precipitation particles
Slab Layer Grain Size
0.30mm
Slab Layer Hardness
P-
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year