Avalanche: Monte Cristo

Observer Name
Aaron Rice
Observation Date
Thursday, March 13, 2014
Avalanche Date
Wednesday, March 12, 2014
Salt Lake » Little Cottonwood Canyon » Monte Cristo
Location Name or Route
Monte Cristo - Upper Bowl
Slope Angle
Trigger: additional info
Unintentionally Triggered
Avalanche Type
Soft Slab
Avalanche Problem
Wind Drifted Snow
Weak Layer
Density Change
A bit late, as I was taking advantage of the amazing weather all day yesterday and didn't get around to writing this up. The avalanche problem that showed its face in this incident was well documented in other reports and in the advisory today, so I thought about not writing it up, but I think there is an additional good lesson to be learned from this particular incident.

We started out at the Alta trailhead at 5:30 and skinned up to Superior. We estimated about 50-100 people were skinning up. we counted about 20 headlamps ahead and more than that behind, and it seemed that only half the people had their headlamps on as the snow made it bright enough with out them. Our objective was not the south face however, we were going to ski Monte Cristo.
As we got to the top at 715, the wind was really blowing and transporting a good amount of snow. But today was the day to ski MC... and we didn't even want to think about skiing the south face with 50 other people. We skied the edge of the world line off the top of MC. I skied first. The snow was definitely wind affected, but mostly scoured as the wind was mainly out of the north. None of our group of 3 had ever skied MC and I was not sure exactly how to get into the the chute proper, so I slowed down a bit and traversed east towards superior. I crossed a couple small gullies. The second one instantly spidered under my feet. I kept moving and easily made it to the ridge 10 or so feet away. I looked back and the snow had fractured 20+feet above my track and 50 feet down the ridge along the gully. It then picked up a bit of speed and poured over cliffs and into MC gully where it was hard to see how far it went. I am guessing it went a good ways as it looked to still have a bit of speed as it went out of sight (maybe 800ft vertical).

The other 2 in my party and another party of 2 (making 5 ppl total) skied down to me. We all stood there for a bit looking above us at more windloaded terrain- some of which looked a bit thicker and harder. I was a bit shaken and we eventually decided to skin and boot back out, via the "edge of the world" line where there was a scoured strip of snow.

The instability that we came across was new snow and thin soft windslab instability. Danger that I have always referred to as manageable. However, we were in hard to manage and unfamiliar terrain, making the danger less manageable or as we decided unmanageable. I was a bit shaken by the experience, and learned that manageable avalanche danger is only manageable in manageable terrain.
picture 1: A windloaded sunrise - should have put up some red flags for us.
picture 2: Edge of the World - more wind transport, we did think about this slope being scoured as a safe thing, but neglected to recognize that the slopes below would be loaded.
picture 3: ski track in yellow, crown in red. Not a big, wide or deep avalanche, but not something you would want to get tangled up in either.