Twin Lakes Fatal Avalanche

Location Name: 
Granite Mountain NNE Face Above Twin Lakes
Region: 
Goose Lake Area
Date and time of avalanche (best estimate if unknown): 
Sun, 01/31/2016 - 13:00
Location Map: 
United States
45° 5' 57.84" N, 116° 11' 28.914" W
US


Red Flags: 
Recent avalanche activity
Obvious avalanche path
Terrain Trap

Observation made by: Forecaster
Avalanche Observations
Avalanche Type: 
Slab
Slope: 
38degrees
Trigger type: 
Snowmobiler
Crown Height: 
2 ft
Aspect: 
Northeast
Weak Layer: 
Other - explain below
Avalanche Width: 
150ft.
Terrain: 
Near Treeline
Elevation: 
7 700ft.
Bed Surface: 
Other - explain below
Avalanche Length: 
200ft.
Number of similar avalanches: 
2
Number of people caught: 
1
Number of full burials: 
1
More detailed information about the avalanche: 

 

Unfortunately, a snomobiler was fatally caught and buried while climbing a steep, complex gully on the leeward, North face of Granite mountain on Sunday afternoon of the last day of January 2016. The slab avalanche failed on our persistent slab problem that we had been tracking---buried surface hoar 80 cm/ 2.5 feet down that formed around Christmas...we could not get the layer to fail in our stability tests on the crown, and believe that the slide may have been triggered from a thin spot in the slab on the flank, in the chute where a snowmobile could saw through the weak layer easier? The victim was wearing a beacon, deployed his airbag, and ended up buried underneath 5 feet of debris near the bottom, asphyxiating before being dug up after 15-20 minutes. CPR was un-successful.

Avalanche Photos: 
Snowpit or crown profile photo or graph: