Avalanche: Hatcher Pass

Location: Arkose Peak, North Ridge

Route & General Observations

On January 7 a party of five skiers remotely triggered an avalanche in a nearby gully while ascending the north ridge of Arkose Peak on a westerly slope in Hatcher Pass (southeast of Lonesome mine). No skiers were caught.
Though we had no signs of instability on our approach, we were closely monitoring slope angles and were travelling on 30d or less slopes. On a broad slope to the right of a major gully, I skinned slightly closer to the gully than the others. Upon turning, I felt and heard a large whoomph and ‘rolling thunder’. We observed the lower third of the avalanche from our location. On the ski down the broad slope Elena and John reported shooting cracks. The day was mostly clear and calm with temperatures in the 20’s.
With closer inspection, the crown face was about 1’ with the right flank (climbers view) upwards of 3’ with two significant slabs. The crown face was at ~4,400’ and the runout zone at 3,600’. The debris was contained within the gully spread over about 300 yards and possibly 10’ deep or more.

Contact, Location & General Observations
Enter your contact information and a location for this observation. Note that you can submit anonymously, however if you would like to share your name with staff, but not the public, select No for "May we include your name in your observation"
Forecaster Comments

A great example of the untrustworthy nature of buried persistent weak layers. Traveling in avalanche terrain will continue to require attention to safe travel techniques and preparedness for rescue in the chance that you are able to trigger an avalanche. Buried persistent weak layers will continue to be problematic throughout the season, although the likelihood of triggering this avalanche problem will vary between periods of varying sensitivity and activity.
Buried persistent weak layers will also continue to allow people to trigger avalanches from above, adjacent to, from below, and remotely (such as this avalanche).
While many recreators were able to ride a large variety of terrain without incident this weekend, this avalanche demonstrates that while likelihood is low, consequence is high enough to bury, injure or kill.

Avalanche Details
If this is an avalanche observation, click yes below and fill in the form as best as you can. If people were involved, please provide details.
Trigger SkierRemote Trigger0
Avalanche Type Hard SlabAspect Southwest
Elevation 4100ftSlope Angle 30deg
Crown Depth 12inWidth 200ft
Vertical Rununknown  
Red Flags
Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.
Observer Comments

None until the avalanche.

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

Calm winds, mostly clear skies, shadowed terrain, mid 20's temperature.

Snow surface

2" of fresh dry snow over very hard non-breakable crust.


Not done.

Photos & Video
Please upload photos below. Maximum of 5 megabytes per image. Click here for help on resizing images. If you are having trouble uploading please email images separately to staff.