Nat Grainger, Jesse Dudley, Andy Bond, Zach Miller

Salt Lake » Big Cottonwood Canyon » Days Fork » Two Dogs

Day's Fork, Two Dogs

10,100'

North

39°

Unknown

Cornice Triggered

Soft Slab

Persistent Weak Layer

Facets

2.5'

60'

600'

Standing in the flats of Upper Days, we watched a cornice-triggered slide come off of the Days Headwall just east of Two Dogs. Slide had come off the ridge and stepped down to bare ground with a 16-30" crown 50-70 ft. wide. Ran full-track and as it went over the cliffband triggered another pocket about 1 ft. deep. Debris was 2-3.5 ft. deep by around 40 ft. wide with some impressive-sized cornice chunks (5-10 ft. long) that had run the full path. The path was littered with talus, trees, and cliffs and would NOT have been pleasant or manageable to take a ride through. Slide took out ski tracks in two different shots from earlier in the day.

Of note, we saw multiple parties kicking cornice with little regard for others in the area and below in the slide paths. The fact that the problematic layer has been recently identified as the below-rain facets but that this one pulled straight to the bed surface indicates the serious power and weight cornices can have on the sensitivity of the current snowpack. Cornice Awareness is something that should be taken seriously right now in our wind/rain/facet layer cake scenario. Even skinning close-to or skiing within the general proximity of the ridges can trigger heavy pieces that may have detrimental implications on the snowpack and people below. Immediately post-avalanche we encountered multiple solo travelers crossing the debris pile and similar slopes without beacons. Other questionable etiquette recently throughout the northern powder circuit.