My partner and I ascended Patterson Ridge, following a skintrack that had been put in shortly before us. At around 9400’, the track led looker’s left above the Kessler Slabs. This put us on to an exposed/wind-loaded 40-degree NE slope (measured with inclinometer) leading away from the ridgeline. We switched back into the trees and began to immediately notice cracking in the new snow. As we made our way back to the ridge, snow collapsed 3 feet below me on the OS/NS interface. 2” of sluff ran further out of sight. I dug a hand-pit and noted that the snow was 12”-14” and bonded very poorly with the melt/freeze crust beneath. Aware of the instability and windloading on the NE aspect, we proceeded one at a time between islands of safety back to the ridge separating Kessler Slabs and God’s Lawnmower where windloading was not noted (snow depth about 8”). At 9600’, we watched a loose-dry sluff run from the top of Kessler about 1500’ through a gully on The Mower.

We were forced to decide between descending Patterson’s ridge or continuing onto the face of God’s Lawnmower. While the ridge is heavily treed, we felt the trees were unlikely to provide anchor to possible soft-slab avalanches that may run on the steep slope. It seemed likely that any slide big enough to carry us would take us through a ride into trees and other hazards below. We therefore opted to carefully make our way on to the face of God’s Lawnmower. We felt that we could more effectively navigate the slope by skiing one at a time and avoiding terrain traps that could pile up debris or take us through rocks and trees.

I proceeded first, making a ski cut to an island of safety with no reactivity. I signaled to my partner to leap frog me to another island of safety a few hundred feet below and she made her way to a stop. I took a couple of turns on the treed slope towards my partner. In doing so, my sluff triggered a slab about 50’ below me which ran for about 150’. I made my way to my partner and came to a stop. Very spooked now, we decided on the next island of safety on an elevated knob in the mellower terrain below us. We met at the knob (approx. 8700’) and assessed the terrain below us. The slope became steeper with a convex rollover ahead of us and skier’s right. Skier’s left was a slight gully with a mellow transition to the flat terrain below us. The slope was not as steep as the section that we had just descended, but I failed to measure the slope angle at this point.

My partner descended left and made two turns out of my view. I began to move to get her back in view and immediately heard her yelling from below. I dropped further and unknowingly onto some hangfire from the avalanche that she had triggered. I could see the debris had run onto the flat terrain but did not immediately see my partner. While pulling out my beacon, I noticed that she was sitting upright on the bed surface about 2/3 down the slide path. I descended the bed surface to her. She was slightly shaken up but otherwise fine. Luckily, we had made it out of the steep terrain and were able to pick our way carefully back to the car.

The avalanche was about 80’ wide and ran for about 250’ on the OS/NS interface (as expected). We chose to ski this slope knowing the possibility of a slide occurring, confident that it would be unable to fully bury a person and that it was clear of any terrain hazard. The aspect we skied was not windloaded, but the new snow was extremely reactive on the melt-freeze crust below. We recognized significant instability signs while ascending but unfortunately had ascended far enough that we faced a tricky decision on where to descend safely. I believe that careful decision-making and clear communication between partners was pivotal to our outcome today. I stand by our decision to continue onto the face of God’s Lawnmower. From our position, we could effectively ski the face carefully and avoid its terrain traps. The ridgeline presented a more significant terrain hazard in my opinion.

However, our day was not without its mistakes. Following the previous skintrack led us into dangerous terrain away from our intended goal. I failed to measure the slope which failed and was also out of sight as my partner was carried. We also opted to ski higher-consequence terrain in moderate conditions with known hazard—I ultimately underestimated the reactivity of the new snow. This was a great learning experience for both of us and we are happy to be alright.