Snowmobiler triggered hard slab avalanche Sheep Mtn.

...we rode over the saddle between Sheep and Scotch Bonnet and saw an avalanche that appeared very recent, and likely triggered by a snowmobiler. It was on a west facing slope at 10,000', and was a hard slab 1-4 feet deep and 150' wide, ran about 200' vertical. AMu-HS-R3-D2-O. This was a clear sign that weak layers exist, especially where the snowpack is relatively shallower, and recent snow has been drifted into thick slabs that are unstable over this weak snow.