CAIC

Avalanche Details

Location: Highlands Ridge, Desolation Row, Aspen zone
State: Colorado
Date: 2011/04/04
Time: 1:15 PM
Summary Description: 1 skier caught and killed
Primary Activity: Sidecountry Rider
Primary Travel Mode: Ski
Location Setting: Sidecountry

Number

Caught: 1
Partially Buried, Non-Critical: 0
Partially Buried, Critical: 0
Fully Buried: 1
Injured: 0
Killed: 1

Avalanche

Type: SS
Trigger: AS - Skier
Trigger (subcode): u - An unintentional release
Size - Relative to Path: R1
Size - Destructive Force: D2
Sliding Surface: O - Within Old Snow

Site

Slope Aspect: NW
Site Elevation: 10900 ft
Slope Angle: --
Slope Characteristic: Sparse Trees,Gully/Couloir

Avalanche Comments

Compared to the overall size of this path, the skier triggered avalanche that occurred on April 4th was very small. Due to the shape of the terrain, a large start zone funneling into a narrow gully and through a small cliff band, the consequences of triggering even a small avalanche are very high.

Weather Summary

Larger scale weather patterns during the winter of 2010-2011 were dominated by La Nina. This had resulted in above average precipitation in all areas of the Roaring Fork Valley. As of early April, SNOTEL weather stations showed 118% of the the average precipitation for this winter season. The weekend prior to the accident saw some significant swings in the local weather conditions. Saturday April 2nd had clear skies and very warm temperatures.Local weather stations showed high temperatures that afternoon of 47F near treeline elevations. The morning hours of Sunday April 3rd saw a powerful and fast moving storm pass through the area. Strong southwest winds blew at higher elevations and snow totals of 12-15 inches were reported at nearby ski areas during a 12 hour period. Lightning was also observed during the morning hours. On Monday April 4th, the day of the accident, skies again cleared. Temperatures were cool during the morning hours and they warmed up gradually throughout the day. The group reported "perfect" weather with blue skies and calm winds.

Snowpack Summary

Due to the nature of the terrain, rapid warming, and increased wind loading, CAIC staff were unable to gather any snowpack observations at the crown face of the avalanche. After conducting interviews with the group and examining photos of the crown, it appears that the slide was triggered from a shallow spot in the snowpack. It initially fractured around 6-8 inches deep in the upper snowpack. The avalanche then propagated across the slopes into an area of deeper snow. The storm on Sunday April 3rd, the day before the accident, did produce one large natural avalanche on the Highlands Ridge about 1 mile north of the accident site. It ran on the same northwest aspect and at a similar elevation. Both of these avalanches failed in old snowpack layers.

Events Leading to the Avalanche

On April 3rd, a group of four riders made plans to ski steep lines off of Highlands Ridge. On the morning of April 4th, they met early, and a 5th friend joined them. They first skied a backcountry line known as Green Trees in Maroon Bowl. After this first lap, they regrouped to ski a line one bowl to the south of Maroon Bowl known as Desolation Row. The group used chair lifts at the Aspen Highlands ski area to access the terrain for both runs.

Accident Summary

The avalanche path, Desolation Row, drops from the Highland Peak ridge line down into the Maroon Creek valley. The group entered this path just above treeline on a west facing rib that made up the skiers right side of the path. They spaced out and skied one at a time for several short pitches down this initial section. As the group reached treeline elevations, they made a traverse to the skiers left side of the bowl into northwest facing terrain. On this traverse, the group again moved one at a time. The fourth skier moved quickly across this traverse and near the end of it, triggered a slab avalanche from a shallow spot in the snowpack. The crown face of this avalanche was only 6-8 inches deep at the trigger point. It quickly propagated across the slope and became much deeper. Skier number 5, towards the end of this traverse, got very close to the 4th skier in an effort to shoot some video with a camera he carried. He was caught in and killed by the avalanche that was triggered just in front of him. One contributing factor to this accident was the lack of distance between the 4th and 5th skiers during their traverse.

Rescue Summary

The group executed a quick companion rescue (approximately 15-20 minutes), first by descending complicated steep terrain. After 10 minutes of descending, they picked up a signal with their avalanche beacons, pinpointed, probed and were performing CPR in an additional 6 minutes. After approximately 45 minutes of CPR, they decided they could not revive the victim and continued to descend to call 911. Mountain Rescue Aspen deployed to the scene and decided it was unsafe to proceed with the recovery that afternoon. Mountain Rescue Aspen and staff from the CAIC went into the accident site during the early morning hours on April 5th, and retrieved the victim by 10:30 am.

Comments

Despite the outcome, the group of backcountry skiers involved in the avalanche performed a rapid and efficient search for their buried partner. Mountain Rescue Aspen worked quickly and diligently the day after the accident to recover the victim.