Small rider triggered Avalanche Lionhead

LIONHEAD AREA
Lionhead Range
Code
SS-AM-R1-D1
Aspect
S
Latitude
44.72920
Longitude
-111.32300
Notes

We saw this today after it happened. Looked like a snowmobile triggered it. I believe it is mostly south facing. Thanks. 

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Snowmobile
R size
1
D size
1
Slab Thickness
12.0 inches
Vertical Fall
75ft
Slab Width
20.00ft
Snow Observation Source
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year