Avalanche: Twin Lakes Pass

Observer Name
Coyne/Fredbo/Conover
Observation Date
Saturday, December 14, 2019
Avalanche Date
Saturday, December 14, 2019
Region
Salt Lake » Big Cottonwood Canyon » Twin Lakes Pass
Location Name or Route
Twin Lake Pass
Elevation
10,000'
Aspect
East
Trigger
Skier
Depth
2'
Width
1,500'
Comments
Backcountry 101 Course
Tour started out of the Brighton Region to Twin Lakes Resevoir to Twin Lakes Pass.
Making wise terrain choices minimize exposure and risk the group navigated terrain well, focusing on aspect and slope angle. Appoximately 300-400ft below the Twin Lake ridgeline the group noted cracking as they broke trail due to increase PI and windloading. We stopped to regroup and discuss risk/ hazards/ and managing a smaller pocket of wind slab. With a plan in mind, we had one skinner continue upwards, 10 steps later the trailbreaker unintentionally triggered a small wind pocket on a benign slope. The failure of this small slope then sympathtically triggered several other avalanches above us throughout Highway to Heaven (1000ft wide) and then off toward the Heaven's Gate side of the pass. NE-E-SE aspects running approx. 60ft on smaller slopes and 300ft on larger slopes in the D2 range. Likely failing on prefrontal graupel pooling below rocky cliff bands that was loaded by New Snow/ Wind Loading. One small pocket directly off the pass looks to have failed to the ground on facets? The group had made solid terrain choices to ascend and we were on a safe ridge out of slide paths. We did not proceed forward to check out the crowns, ripped skins, and skied back down our skin track. Our BC 101 got a full value day.