23-24

Snowmobiler triggered Avalanches (2) near Lulu Pass, Cooke City

Lulu Pass
Cooke City
Code
HS-AMu-R3-D3-O
Elevation
10200
Aspect Range
E-N
Latitude
45.07090
Longitude
-109.95800
Notes

A rider on 02/23/2024 triggered a large avalanche on the north side of Fisher Mountain near Lulu Pass. He was caught and carried downhill but luckily was not buried or injured. On the east side of the mountain, another avalanche was observed by the party and likely happened at the same time. This avalanche either happened sympathetically from the large slide or was remotely triggered by the rider. 

Number of slides
2
Number caught
1
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
Snowmobile
Trigger Modifier
u-An unintentional release
R size
3
D size
3
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness
36.0 inches
Vertical Fall
200ft
Slab Width
200.00ft
Snow Observation Source
Slab Thickness units
inches
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Riders on 02/23/2024 saw an avalanche that appeared to of broken naturally. However, a rider on 02/23/2024 triggered a steep slope around the corner and could likely have remotely triggered this avalanche as well. Photo: D.Shelley

Cooke City, 2024-02-23

A snowmobiler triggered a large avalanche on the north side of Fisher Mountain on 02/23/2024. He was caught and carried downhill but luckily was not buried. Photo: D.Shelley

Cooke City, 2024-02-23

Remotely Triggered Avalanches above McAtee Creek

Buck Ridge
Northern Madison
Code
HS-AMr-R2-D2-O
Elevation
9600
Aspect
NE
Latitude
45.17490
Longitude
-111.44600
Notes

From obs: "North facing aspect above McAtee creek.  Triggered one remotely while traversing below, ~150 yards away, and likely triggered the second one from below as well but cannot confirm. 4-6 foot crowns, 50-100 yards wide, ran 75-100 yards"

Number of slides
2
Number caught
0
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
Snowmobile
Trigger Modifier
r-A remote avalanche released by the indicated trigger
R size
2
D size
2
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness
48.0 inches
Vertical Fall
200ft
Slab Width
250.00ft
Snow Observation Source
Slab Thickness units
inches
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Riders triggered this pair of avalanches while crossing below this terrain, roughly 150 yards away. The location of the triggers is marked by the "x's" in the photo. Photo: M. Rolfson 

Northern Madison, 2024-02-23