Snowmobile triggered avalanche resulting in fatality near Lost Lakes

Location Name: 
Forestdale Divide
Region: 
Carson Pass Area
Date and time of avalanche (best estimate if unknown): 
Fri, 03/02/2012 - 15:30
Location Map: 
United States
38° 40' 7.32" N, 119° 57' 19.908" W
See map: Google Maps
US


Red Flags: 
Recent avalanche activity
Whumphing noises, shooting cracks, or collapsing
Recent loading by new snow, wind, or rain
Obvious avalanche path
Terrain Trap
Observation made by: Forecaster
Avalanche Observations
Avalanche Type: 
dry,slab,
Slope: 
40degrees
Trigger type: 
Snowmobiler
Crown Height: 
5 ft
Aspect: 
Northeast
Weak Layer: 
Old Snow
Avalanche Width: 
190ft.
Terrain: 
Above Treeline
Elevation: 
8 400ft.
Bed Surface: 
Old Snow
Avalanche Length: 
1 140ft.
Number of people caught: 
1
Number of full burials: 
1
More detailed information about the avalanche: 

A 35 year old male snowmobiler triggered this slide around 3:30 on March 2nd. The avalanche carried him down the slope and into trees. The slide buried the snowmobiler 3 to 4 feet deep. His partners located him and determined that he did not survive the avalanche and subsequent burial. Search and rescue recovered his body March 3rd after calling in Kirkwood Ski Patrol to mitigate the remaining avalanche hazard with explosives. The explosives triggered a second avalanche in the path to the climbers left of the snowmobile triggered slide.

Both avalanches failed on the crust/facet combination below the new snow. The crown of the snowmobile triggered avalanche ranged in depth from 6 inches to 5 feet with an average crown depth of 4 feet. The slopes near the avalanches had large (100 ft long and 3-4 ft deep) shooting cracks in them.

Photos 1 and 2: Snowmobile triggered avalanche crown from the side

Photos 3 and 4: Overview photos showing both the snowmobile triggered avalanche (looker's right) and the explosives triggered avalanche (looker's left)

Photo 5: The victim's snowmobile. Note the broken frame, bent tunnel, and other severe damage to the sled.

Photo 6: Google earth image of the slide.

Our thoughts and sincere condolences go out to the family and friends of this snowmobiler.

Snowpit or crown profile photo or graph: 
Avalanche Photos: 
Avalanche observation video: 

Snowmobiler triggered avalanche near Lost Lakes

Weather Observations
Air temperature: 
Precipitation: 
Air temperature trend: 
Wind Direction: 
Accumulation rate: 
More detailed information about the weather: