CAIC: Colorado Avalanche Information Center

2020/02/10 - Alaska - Boulder Creek Drainage, South of Cooper Landing

Published 2020/02/12 by Wendy Wagner - Chugach National Forest Avalanche Center

Avalanche Details

  • Location: Boulder Creek Drainage, South of Cooper Landing
  • State: Alaska
  • Date: 2020/02/10
  • Time: Unknown
  • Summary Description: 1 snowmobiler caught, buried, and killed
  • Primary Activity: Snowmobiler
  • Primary Travel Mode: Snowmobile


  • Caught: 0
  • Fully Buried: 1
  • Injured: 0
  • Killed: 1


  • Type: HS
  • Trigger: AM - Snowmobile
  • Trigger (subcode): --
  • Size - Relative to Path: --
  • Size - Destructive Force: --
  • Sliding Surface: O - Within Old Snow


  • Slope Aspect: W
  • Site Elevation: 2600 ft
  • Slope Angle: 45 °
  • Slope Characteristic: --

Accident Summary

On February 10th, 2020 a snowmachiner was riding on west facing terrain above Boulder Creek. The rider triggered a slab avalanche 150′ wide, 3′ thick and running around 250′ down the slope. The rider was caught, carried and fully buried. Riders nearby saw the avalanche and began rescue efforts immediately. The rider was recovered and did not survive.

The avalanche failed on very weak faceted snow that formed during the early January dry and cold period. The slab over the weak layer was composed of hard snow that had been wind affected. The crown face thickness varied from 1 to 5 feet due to wind loading and scouring but averaged 3 feet. It is unknown where the avalanche was triggered.





Image Missing
Figure 7: Avalanche Flank Profile