I was caught in an avalanche today on a north facing slope on Santaquin Peak. The terrain where it happened consists of a maybe 600 vertical foot headwall that is sparsely treed narrowing to a gully that runs for 2,500 vertical feet. This is a pretty rarely skied area, and is a quite massive slide path that seems to run big regularly. There was evidence of a very large avalanche presumably from early January that snapped many trees and ran full track, producing a massive, probably 15-20 foot deep debris pile at its toe.

I was skiing in a group of three, and we were using this run as an exit run late in the afternoon after skiing several runs on Santaquin. We all congregated at a safe spot on the ridge the top of the run, with a great visual of the entire slope (see attached photo.) With my partners watching I dropped into the run, skiing the headwall somewhat fast and aggressively. The snow was untracked and consisted of very deep near surface facets untouched by the wind and was excellent skiing. I slowed down as the terrain narrowed into a gully, and was hit with what felt like a wall of snow. I fought hard to self arrest, sliding with my feet facing downhill and arms digging in to the bed surface. I very briefly was buried and then came up to the surface again, and was just barely able to stop myself. Before I could breathe a sigh of relief I was hit by another wave, got carried again and can't remember if this one ever buried me but I was able to self-arrest more quickly this time. I then deployed the airbag on my pack in case another wave hit and skied to the side so I was out of the line of fire. I was probably carried a max of about 100 vertical feet but was barely able to self arrest and felt like I could have easily been carried much further. I lost a pole in the slide (but found it about 1,000 vertical feet lower) and sustained no injuries. The slide path was mostly clean but there was a rock band quite a bit lower that could have easily caused an injury had I been carried over it. I was shocked by how much snow there was and how fast it moved considering it was entirely my sluff that started following me as soon as I dropped into the line.

Takeaways:

1). We didn't respect the terrain and did not discuss potential hazards of skiing this particular line. Due to perceived low avalanche danger we didn't perform many of our usual protocols for skiing in avalanche terrain. A simple ski cut likely would have made me aware of this problem, instead I charged straight into the line. On a similar note, either checking over my shoulder or just checking up on the side before the run narrowed likely would have made this a non-issue. I definitely feel like I let my guard down big time.

2). We had skied two other runs previously, on NW and N aspects and sluffing was only a minor concern. Additionally we have done quite a bit of skiing these past few weeks and any encounters with this snow stability problem were very manageable and unremarkable. While similar in steepness to our previous runs, our last run was quite a bit more radical in terms of terrain features and runout zones. Additionally the snowpack was much shallower due to the large January avalanche and this may have contributed to the snow being even more faceted and weak.

3). Radios may have helped in this situation. My partner yelled at me when he saw what was happening but I was already too far down the slope and couldn't hear him.

I was amazed at the sheer volume of snow that came down solely from my sluff. While being a somewhat unusal problem with our faceted snowpack it is definitely something that I will be much more vigilant about going forwards. Photo is a top-down view of the run before we skied it.