Details sketchy. I stumbled onto this avalanche not long after it occurred. It was after the wind was slowing this morning. It appears that snowmobilers were playing on small hills below the avalanche path and most likely triggered it from below. It overran some of their tracks. I was not able to get onto the debris because of dangerous conditions between me and the avalanche. I contacted Alta Central and Alta Ski Patrol. Some patrollers were able to view the path from high on the ridge and since no one was doing a search of the debris and also a couple of snowmobilers still riding near the area, it was assumed that no one was caught.
I dug the snowpit in this video just prior to finding the avalanche. I suspect a very similar structure was present on the slope that avalanched.