Deep Slab Avalanches in Cooke

Ben Zavora of Beartooth Powder Guides and the GNFAC investigated a skier triggered avalanche near Daisy Pass (3/2). It was remotely triggered (they were not on the slope) and failed on a layer of feathery surface hoar crystals that formed in early January. The slab was 4 feet thick and very dense and termed a Deep Slab Avalanche. The recent snow and wind added weight and stressed this layer to its breaking point. In January we found surface hoar on all aspects, so it's a bit scary. Remotely triggering a 4' deep hard slab avalanche is dangerous. The slope angle at and near the crown was only 31-32 degrees; very shallow. Surface hoar is known to break on less steep slopes, which can catch us off-guard.

It's time to recalibrate our thinking because deep slab avalanches are deadly, yet not very widespread. It will become a low-probability, high consequence problem.