Avalanche: Hatcher Pass

Location: South side of marmot near Rae Wallace

Route & General Observations

Started at Fishhook parking lot, skinned up to Marmot and continued on the SE side of the ridge to Rae Wallace. At higher elevations ski crampons were helpful for ascending on the windboarded snow. Near the peak of Rae Wallace, we transitioned to skiing.

Avalanche Details
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Trigger SkierRemote Trigger Unknown
Avalanche Type Soft SlabAspect East Southeast
Elevation 4500ftSlope Angleunknown
Crown DepthunknownWidth 20ft
Vertical Run 1000ft  
Avalanche Details

After transitioning, we crossed a few feet above a "whale's back", and continued a few hundred feet below the ridgeline. About 50 yards past the whale's back, we saw avalanche debris travelling downslope and into the creekbed. The crown was about 15 feet below our ski tracks that were above the "whale's back". We did not have any red flags prior (no shooting cracks, no whoomphs, no crowns), and did not hear the avalanche. It appeared that the slab started relatively small, but the debris collected surrounding snow as it ran toward the creekbed. The debris continued moving quickly in the creekbed. We continued forward to get a better view of the area below and determined that there were no other people in the area of the creek. We did determine that an area we had previously thought was wind affect was likely old debris from a small wind slab on a more southern aspect of the bowl, but it did not appear to be recent.

Events of the day

Traveled back the way we came, and determined with a probe that the "whale's back" was a wind created feature, kind of like a cornice, but on terrain that doesn't provide an opportunitiy for much overhang. We did not see any cracks connecting our ski tracks to the crown, and estimate that our weight created a wedge type of feature, pushing the snow underneath the "whale's back" and triggering a wind slab to release. No other signs of instability on the ski out, just lots of variable snow surface quality.

Rescue events


Weather & Snow Characteristics
Please provide details to help us determine the weather and snowpack during the time this observation took place.

Flat light and good light traded off throughout the day.

Snow surface

A little bit of everything, wind affect and wind board at higher elevations, some soft snow and a lot of breakable crust at lower elevations.


No formal stability tests.