CAIC: Colorado Avalanche Information Center

2013/02/02 - Colorado - Cement Creek, north of Gladstone

Published 2013/02/06 by Ann Mellick, Susan Hale - Forecaster, CAIC


Avalanche Details

  • Location: Cement Creek, north of Gladstone
  • State: Colorado
  • Date: 2013/02/02
  • Time: 2:00 PM (Estimated)
  • Summary Description: 2 skiers caught, 2 partially burried
  • Primary Activity: Backcountry Tourer
  • Primary Travel Mode: Ski

Number

  • Caught: 2
  • Fully Buried: 0
  • Injured: 0
  • Killed: 0

Avalanche

  • Type: SS
  • Trigger: AS - Skier
  • Trigger (subcode): u - An unintentional release
  • Size - Relative to Path: R3
  • Size - Destructive Force: D2
  • Sliding Surface: O - Within Old Snow

Site

  • Slope Aspect: E
  • Site Elevation: 11700 ft
  • Slope Angle: 38 °
  • Slope Characteristic: Concave Slope,Planar Slope

Accident Summary

This incident occurred in close proximity (in both time and space) to a fatal avalanche accident. In both cases, the characteristics of the slope (aspect and elevation) and the snowpack (slab and weak layer) were very similar. The avalanches released within about 20 minutes of each other. Although in many ways these avalanches were quite similar, the outcome for the two parties was quite different. The account of the fatal avalanche accident is described in a separate report. 

This area is accessed via County Road 110, just north of Silverton Mountain Ski Area. The group dug a snowpit on their first ascent. It was on an east-facing slope that was near treeline. They described the results of their snow profile as "moderate" and decided to continue skiing. The group skied one run on the east-facing terrain just to the skier's right of the typical uptrack, and another on more north-facing terrain. During both runs the group did not see any cracking in the snowpack or observe any whumpfing. They skinned back up to the summit for a final run,  where they saw another party of three about to ski similar terrain. They decided to descend down the east face a little further to the skier's right (the other group they saw proceeded around the cirque to ski a different line).  

All three party members skied about 1/3 the way down to a steeper rollover.  Skier 1 dropped directly onto the slope and made about 10 turns before traversing off to the side to wait. Skier 2 skied down toward Skier 1, stopping about 10 feet further downhill.  During Skier 2's descent the slope fractured and Skier 3 yelled warnings.  Both Skiers 1 & 2 tried to move out of the way.  Skier 1 braced against a tree and was pinned up to his waist.  Skier 2 was able to move farther away and managed to stay upright as snow gathered up to his thighs.  Skier 3 watched safely from above, spotting his friends. Party members stayed in voice contact. Skier 3 helped dig out Skier 1, while Skier 2 dug himself out. 

They all descended the debris and exited the area via County Road 10.  On their way out they noticed fresh avalanche debris 15-20 ft above the road. They decided to go back and investigate because the group of skiers they saw at the top of the run was headed in that direction. As they traveled uphill they met one of the skiers from the other group. This skier explained that all three of them had been caught in an avalanche. One of the members of his group was injured and the other was likely deceased.

Skier 2 left to notify the ski patrol at Silverton Mountain. After deciding it was unsafe to go back up the avalanche path, Skier 3 also left to go help find patrol, as he was more familiar with the ski area.  Skier 1 remained with the victim. 

Note: After pondering the chain of events, Skier 1 later commented that their snowpit location was fairly representative of the first lines they skied, but ultimately less representative of the slope that avalanched (the snowpit was on an easterly aspect near treeline).  The first two laps were also in more moderate terrain - less steep, tighter glades and without the steep breakovers. 

Media

Images

Snowpits

Image Missing
Figure 12: A snow profile observed at crown of the avalanche.