A rider triggered a large avalanche that carried his snowmobile downslope into a tree. He managed to jump off his machine as the slide broke and escaped being carried. He did not deploy his airbag and was uninjured. The snowmachine tumbled downslope and hung up on a tree.
The rider had nosed over a convexity and started sidehilling when the avalanche released. It broke on a northeast-facing slope at about 5800 feet elevation. The crown was about 75 yards wide and debris ran roughly the same distance down slope. The crown was 18-20 inches deep and the slide appears to have run on weak facets above the 1/13 crust. The rider and his partners were wearing avalanche rescue gear and had read the day's forecast. They were aware of the heightened danger on northeast slopes and were stepping out carefully.
See quick observation for details. Snowmachine not damaged. 4 riders in group.
