Vail & Summit County
AvalancheAnonymous · May 11, 2019 · Vail & Summit County
Weather
Sunny, light wind, 20-30 degrees.
Snowpack
Dust on crust for most of the tour. A 6-24 inch wind slab at the top of the gully below the cornice.
Avalanche
We triggered a D1 windslab at the top of the east-northeast-facing gully just south of the summit of Coon Hill at approximately 12,600 feet. It ran approximately 500 vertical feet. One person was caught and taken for a ride for about 40 feet. One dog was caught and taken for a ride for about 100 feet. There were no injuries or burials; we're not even sure the dog noticed. Events leading up to the avalanche: As a group of three, we left the trailhead at about 7:30 am. We discussed our avalanche concerns for the morning tour, which were primarily windslab. Once in the basin, we made a plan to ski from the summit of Coon Hill. We ascended the ridge to the summit, noting that the snowpack was mostly hardpack and unconcerning. At the summit, we planned to traverse under the cornice to the gully. We discussed that a small windslab might exist, but that it was not large enough to be "concerning." We made a plan to ski cut the gully and ski one at a time. Skier 1 traversed under the cornice and ski cut the gully without triggering anything. He stopped on the ridge just south of the gully in a safer zone. Skier 2 traversed under the cornice and skied the gully without incident. Dog 1 entered and stopped partway down the gully, confused whether she should follow Skier 1 or 2. Skier 3 (a snowboarder) traversed under the cornice; Dog 1 started to run uphill towards Skier 3. At the top of the gully, directly under the cornice, Skier 3 triggered a small wind slab under his feet. He arrested on the bed surface as the slab slid by him. The slide was not large or fast-moving enough for him to feel the need to trigger his airbag. Dog 1 was caught by the slide and took a ride for approximately 100 feet before exiting the slide. The slide continued another ~500 feet toward the bottom of the gully. Skier 3 exited the debris and skied down the bed surface to confirm that Dog 1 and Skier 2 were ok. The crown appeared to be 6-8 inches, but slide debris contained hard windslab up to 24 inches thick. There was no cornice failure.