GNFAC investigation: We went and looked at the avalanche that partially buried a groomer without injury to the driver at 8:15 p.m. the night before (2/27). The slide broke on facets at the ground and was 2-3' deep, 100' wide, and ran 600' slope distance. It put 8' of debris on the road cut. The slope was west facing at 7,500' and averaged 38 degree steep in the starting zone . Weak snow at the ground is found throughout our advisory area.
The groomer triggered the avalanche when he was clearing a wind drift from the road. The groomer is badly damaged.
Crown: N45.38528, W111.06487, 7802 feet
Toe of debris: N45.38554, W111.06693, 7482 feet
Alpha Angle: 30 degrees
Billings Gazette Article HERE.