This turned out to be an interesting avalanche. It was the looker's left avalanche that the skier triggered. What I originally took to be a ski track entering the looker's right avalanche was in fact a more shallow crown that then stepped down to trigger a deeper storm slab. The smaller slide was perhaps 5" deep and 25' wide. The looker's right avalanche was triggered by a likely intentional cornice drop (though I bet they couldn't see the results b/c the trees obscured their view below. It was 16" deep and 150' wide...though the debris over-ran the standard cat-track above Michigan City that is commonly used to get to Twin Lakes Pass.

These would be classified as storm snow avalanches with a failure plan of - well - less rimed snow than what was above and below. Rimed dendrites as the failure plane with 2mm graupel above and below...with a 8mm graupel layer 10cm below the bed/failure plane...that was innocent. I was able to elicit full propagation (ECTP29Q2) on this culprit layer as well (see pic below) All academic, but in trying to re-engineer the events (CSI Grizzly Gulch someone called it)...here's what I believe happened -

1. A party ascended the early turn off to gain the Patsy Ridgeline.
2. The dropped a small-ish cornice above the steep gladed terrain that ran through the trees, triggered a 6" graupel slab which then triggered (stepped down) to the 16" deep and 150' wide slide looker's right. Only the party likely couldn't see the results b/c the view was obscured by the trees..and continued another 50' up the ridgeline.
3. They next dropped a much larger cornice (see pic)...but with no results. But had the cornice continued down the slope where it became much steeper, it likely would have triggered the pocket instead of the skier. (2nd pic)
4. 
5. Uncertain if anyone went for a ride...though a catch and carry could have dragged someone through the trees below -