Observation: Chugach State Park

Location: O'Malley NW Gully

Route & General Observations

Noted an obvious slide in the standard hikers route up the NW O’malley gully. Unknown how old it was or it was natural or human-triggered. It appeared to have started about halfway up the gully, and ran to near the bottom; estimated at 500 feet long with the debris field around 100 feet wide.

We dug a few hand pits at around 4200′ during an aborted attempt of the NW ridge and noted an obvious weak layer on the ground, as well as a propensity for the ~6″ slab above it to propagate.

We also noticed a few other smaller slides coming down off the N side of the ridge that connects little O’malley/false peak/o’malley, but none of the them were as large or noticeable as the one in the gully.

Red Flags
Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.
Obvious signs of instability
Recent Avalanches?Yes
Collapsing (Whumphing)?No
Cracking (Shooting cracks)?Yes
Weather & Snow Characteristics
Please provide details to help us determine the weather and snowpack during the time this observation took place.


Snow surface

Melt freeze crust on top, loose and unconsolidated snow below it.


There was 6-8” of snow as we approached the ridge, and at around 4200 feet where we turned around it was as deep as 2’ in some places, although the average depth was around 10”.

Informal snowpack assessments at 4100-4200' on the NW ridge: There was an obvious faceted weak layer on the ground, we dug a few hand pits and were easily able to break a cohesive slab off, which slide on the ground most of the time. Tried to test for propagation by isolating an approx. 4’x 1’ block and pushing on one corner. The whole block broke off in one unit and slid on the ground. Most of these informal tests were conducted on 30-50 degree slopes on a NW aspect. There was another weak layer, that also appeared to consist of facets about 2” down from the top of the snowpack, although in our tests this layer failed much less frequently than the one on the ground.