CAIC: Colorado Avalanche Information Center

2012/02/25 - Colorado - Big Horn Gulch, south of Red Mountain Pass

Published 2012/03/13 by Matt Steen and Spencer Logan - Forecaster, CAIC


Avalanche Details

  • Location: Big Horn Gulch, south of Red Mountain Pass
  • State: Colorado
  • Date: 2012/02/25
  • Time: 3:30 PM
  • Summary Description: 2 skier caught, 1 partially buried-critical and 1 buried
  • Primary Activity: Backcountry Tourer
  • Primary Travel Mode: Ski
  • Location Setting: Backcountry

Number

  • Caught: 2
  • Partially Buried, Non-Critical: 0
  • Partially Buried, Critical: 1
  • Fully Buried: 1
  • Injured: 0
  • Killed: 0

Avalanche

  • Type: SS
  • Trigger: AS - Skier
  • Trigger (subcode): r - A remote avalanche released by the indicated trigger
  • Size - Relative to Path: R2
  • Size - Destructive Force: D2
  • Sliding Surface: O - Within Old Snow

Site

  • Slope Aspect: W
  • Site Elevation: 10520 ft
  • Slope Angle: 40 °
  • Slope Characteristic: Gully/Couloir

Avalanche Comments

This relatively small avalanche ran into a terrain trap. The short drop meant the debris remained soft, but deposited 8 to 10 feet of snow along the creek bottom. A small pocket on the opposite gully wall ran, and another pocket about 50 yards away avalanched sympathetically. All three avalanches were two to three feet deep, and probably failed at the top of the predominant basal facet layer located throughout the zone.

Weather Summary

Snowfall in 2011 was below average on Red Mountain Pass. There were 42 inches of snow in November and 34 inches in December. Snowfall from January 1st to the 16th was only 1.5 inches, nearly nonexistent. By the end of the month, an additional 40.75 inches of snow fell. Snowfall continued into February with 58.5 inches of snow falling between February 1st and the 25th. Total Snow Water Equivalent from the beginning of January to February 25 was 8.2 inches of water.

Snowpack Summary

The shallow early season snowpack and a dry start to January created a layer of weak faceted snow near the ground. Over 8 feet of snow fell between January 1 and February 25. That snow formed a dense slab over the facets. Observers reported widespread cracking and collapsing almost daily throughout late January and early February.

Events Leading to the Avalanche

A party of 8 skiers toured to the west of Red Mountain Pass in the morning. They “preformed multiple snowpit tests.” In the afternoon, the group toured into U S Basin and descended Big Horn Gulch. They planned to ski low angle terrain. The group split up for the descent. We assume that Skiers 1 through 4 were in the first group and Skiers 5 to 8 traveling slightly behind. The group reconvened at the location of the avalanche prior to the event.

Accident Summary

Skiers 1 through 5 were in the gully bottom, while Skiers 6 through 8 were above the incident site in a location upstream in the gully. Skier 1 moved past Skiers 2 through 5 to a point 15 feet away from the group. Skier 1 then collapsed the slope and triggered the avalanche from below but was not caught. At the same time Skier 6 was descending into the gully, upstream from where Skiers 2 through 5 were located. Skier 2 was directly in front of Skier 3, and “was able to push out of the way of the avalanche” and Skiers 5 and 6 were further upstream of the slide. The avalanche caught Skiers 3 and 4. Skier 3 was partly buried-critical, with only a hand above the debris. Skier 4 was fully buried. Skiers 3 and 4 were buried 6 to 10 feet apart. Skier 7 descended to the avalanche site after hearing that the avalanche occurred, while Skier 8 remained in a safe location above the incident site.

Rescue Summary

Skiers 1 and 2 “immediately” grabbed Skier 3’s hand and quickly excavated their face. They cleared snow from Skier 3’s mouth “so they could breath and communicate.” Skier 3 was buried face up, about 2 feet deep.

Skiers 1 and 2 then joined Skiers 5 and 6 and 7 in a beacon search. “The lowest readings on their beacons were 1.8-2.0 m.” One member spot probed the area while others began to dig. It took about 5 minutes to locate Skier 4 and excavate to their head. “Skier 4 was unresponsive but began to breath” once snow was cleared from their mouth. Skier 4 was buried face down, about 6 feet deep. The party dug out Skier 4, then returned to Skier 3.

“Skier 3 was given an Avalung and covered with a jacket to protect them from the hole collapsing and burying them again. It was difficult to prevent snow from collapsing back” into the hole. Neither skier was injured. All their gear was recovered. One or more party members acted as an avalanche spotter at all times.

Comments

Both buried skiers were not wearing Avalungs. An Avalung was given to skier 3 while skier 4 was being excavated. Skier 4 was able to form a small air pocket with their hands.

The party member that reported the incident had some good refelections about the group and rescue.
  • The party was large with mixed abilities. That "complicated communication and decision making."
  • There was a "false sense of security" because the group was at lower elevations and had not seen signs of instability.
  • Navigating the immediate terrain was challenging, and the slope that avalanched was not visible from higher in the gully.
  • Having a point-last-seen for Skier 4 helped the beacon search.
  • Once they knew it was a deep burial, some group members began digging while others probed and continued to pin point.
  • Digging was organized, and the large party allowed for frequent rotations.

Media

Images