Saturday March 20, 2021 - Mt Cokely (North Ridge)
size 2 avalanche on Mount Cokely today (March 20)
Today we were touring up Cokely, there was 2 in our party but we had another group of friends (6 in their party) also touring at a much more casual pace. We started the day by checking out the lower route into the west bowl. After noticing some avalanche signs in the snow pack we opted to avoid the route below the bluffs due to high exposure over the cliffs and obvious travel through prime avalanche terrain. We identified a layer from the recent snowfall about 15cm down at that time. We turned around and took the route over the north ridge to the summit of Cokely.
At the summit we transitioned and dropped in. We hugged the ridge the whole way down and the turns were GOOD however near the bottom of the ridge my partner decided to drop into a steeper convexted north facing aspect. I simultaneously got a little snow hungry and dipped over the edge for a turn… unfortunately this resulted in the entire area sliding. The other group that we knew happened to be crossing the section below us at the same time.
The crown was approximately 15-20cm deep. Both my partner and I seemed to have triggered different areas and it all combined into a very large area. The crown was approximately 100-150m long covering the entire terrain feature. My partner was able to put the brakes on and let the slide move past him as it was a shallow layer. Unfortunately 3 people in the other group made contact with the slide. Due to good spacing 2 people just had their skis covered by the snow. However one person found themself in a bad spot and was taken about 20m in the slide. The slide came to a stop and they found themselves buried up to their shoulders but were still able to move their arms. We quickly dug them out and there was no loss of gear.
Lessons were learned, it was crazy to see such a shallow layer move so much snow. I also think it’s important to note there were approximately 30 people in the backcountry on Cokely today!
Details: Where: Cokely - North Ridge Aspect: North Facing Size: 2 Elevation: Treeline (unsupported terrain as if it was alpine) Trigger: 2 snowboarders at 2 separate points propagating into one slide Burials: 1 partial burial up to shoulders Type: Storm slab Fracture depth: 15-20cm