CAIC: Colorado Avalanche Information Center

2013/01/13 - Colorado - Raspberry Creek, near Marble

Published 2013/01/20 by Scott Toepfer & Brian McCall - Forecaster, CAIC


Avalanche Details

  • Location: Raspberry Creek, near Marble
  • State: Colorado
  • Date: 2013/01/13
  • Time: 2:15 PM
  • Summary Description: 1 skier caught, buried, and killed
  • Primary Activity: Backcountry Tourer
  • Primary Travel Mode: Ski
  • Location Setting: Backcountry

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: R2
  • Size - Destructive Force: D2
  • Sliding Surface: G - At Ground/Ice/Firm

Site

  • Slope Aspect: NW
  • Site Elevation: 10700 ft
  • Slope Angle: 43 °
  • Slope Characteristic: Planar Slope

Avalanche Comments

The last skier (Rider 4) in a group of four initially triggered a shallow, soft wind/storm slab approximately 85 feet wide, and 12 inches deep. Rider 4 was in the process of trying to ride out of this slab when the avalanche stepped down and released a deeper persistent slab which failed on basal facets. This deeper persistent slab was approximately 2 feet deep and 45 feet wide. The avalanche ran an estimated 1,100 vertical feet to the valley floor.

Weather Summary

A low pressure trough moved into Colorado on the night of January 11-12th. This system was supported by a jet stream which brought strong southwest winds to the Marble area during the storm.

Witnesses report that the weather on Sunday January 13th was cold and windy with continued light snow in the Marble area. There are two nearby SNOTEL sites to the incident in Raspberry Creek, North Lost Trail east of Marble at 9,201 feet, and Schofield Pass to the southeast at 10,701 feet. During the storm the Schofield Pass site recorded 10" of snow at 0.8" of water from Jan 11th through the 13th. North Lost Trail recorded 7" of snow at 0.4" of water in the same time period. High temperatures on the 13th reached -1° F at 14:00 at Schofield Pass and 8° F at 14:00 at North Lost Trail.

Snowpack Summary

Small storms during the fall of 2012 left a shallow snow pack in the Marble area prior to December. This snow pack was subjected to prolonged dry and cold periods, forming a base layer of weak facets and depth hoar. December was a snowy month in the area and brought the total snow pack up to a little below average depths. December's snow was followed by an extended cold snap with temperatures falling well below 0° F for many nights prior to January 13, 2013. The consistent cold temperatures drove the development of a persistent weak layers of near surface facets and surface hoar. This layer was buried by the Jan 11th storm snow, and is likely the culprit weak layer for the initial storm slab avalanche. The small storm snow avalanche  then stepped down to the deeper weak layers of depth hoar and facets that formed during October and November. CAIC staff were unable to get to the crown of the avalanche to confirm the exact snowpack structure.

Events Leading to the Avalanche

The west side of Marble Peak ridge has several indistinct gully features that fall steeply into Raspberry Creek. The group had discussed venturing into this area prior to the event of January 13th. They called the area "The Cul de Sacs" due to their proximity to other runs locally known as "the Alley's" on the Yule Creek side of the ridge. They numbered these one through three, with Cul de Sac number three being the furthest south feature.

On Sunday January 6, 2013 Rider 2 and 4 ventured into Cul de Sac 1 (C1), the same path where the avalanche accident occurred a week later. On the 6th, the group stayed on the southwest side of the slight gully feature and noted no instabilities. Rider 2 (with a party of three other riders) returned again on Wednesday January 9th for another tour on the same run, again noting no instabilities, but staying on the more west to southwest aspect of the line. By Sunday January 13 there were nine known sets of tracks on Cul de Sac number 1 from the previous week.

On Sunday January 13 at 09:00, the group of four skiers started their tour off the Yule Creek road by climbing an uphill skin track (the "Alley skin track") . They climbed east-facing terrain to the Marble Peak ridge and made their way along the ridge to west-facing run (Cul De Sac 2), off the backside of the ridge. The group discussed their line and what they might expect from the snow pack. They all agreed to descend one at a time and to stay riders right of the more shaded and wind loaded northwest facing side of the terrain feature.

The first skier down the line reported "spider web" cracks but no collapsing on a portion of his run that ventured a little too far to the skiers left. He reported this observation via radio to the rest of the group on the ridge line. This observation further reinforced their plan to stay riders right in the terrain feature, where the rest of the group descended without incident.

The group then skinned back up a ridge on the north side of Cul de Sac 2. No instabilities were noted on the skin back up to the Marble Peak ridge. Once the group re-gained the ridge they traversed north to the top of Cul de Sac 1. There was no further discussion about the snow pack, and a plan was made for a second run descending Cul de Sac 1

Accident Summary

Rider 1 descended to a prominent lone tree about a third of the way down Cul de Sac 1 (C1) and stopped to act as a spotter for the rest of the group. Rider 2 then began his run staying to the riders right of the sun/shade line that separated the west and northwest aspects and the spotter's tree. Rider 2 stopped at a terrain bench above a rollover that drops steeply towards Raspberry Creek. This was the start of the previously set uphill skin track. Rider 3 then descended a little to the skiers right of the line set by Rider 2. He also stopped at the bench where the up track started.

At approximately 14:15 Rider 4 began his descent and went left of the tracks set by Rider 2 and 3. This took him closer to the wind-drifted and more northwest facing side of the terrain feature. As Rider 4 neared the tree where Rider 1 was spotting from, he made a hard left turn, and triggered a shallow and soft wind-slab in the recent storm snow. Riders 2 and 3 saw a powder cloud develop and yelled at Rider 4 to go left in order to get out of this small slide. At this time Rider 4 was now turning right and heading into the slight gully feature along with the flow of the soft wind slab. He then attempted to make a hard turn back to his left just as the avalanche stepped down to a deeper weak layer near the ground. Rider 4 appeared to lose control when this deeper avalanche started and he was swept into the debris and carried downhill past Riders 2 and 3. Riders 2 and 3 closely watched their partner as he was carried past the bench, over a steep roll in the terrain, and on towards the valley floor approximately 250 vertical feet down slope.

Rescue Summary

Riders 1, 2 and 3 immediately switched their beacons to receive and raced to the valley floor. Rider 1 lagged a bit further behind and checked some likely burial areas for a signal before arriving at the valley floor. Rider 2 picked up a signal quickly and Rider 1 probed and felt what he thought was Rider 4. Riders 1 and 2 began to probe and dig where they thought they had a probe strike, while Rider 3 continued to fine search with his beacon. Rider 1 pin-pointed Rider 4 when hit the victim's boot. The debris was very soft and the rescue team quickly uncovered Rider 4. They estimated that the beacon search, probing, and shoveling took only 5-10 minutes. Rider 4 was found about 115 cm deep in a supine position with his head facing back up slope.

After they uncovered Rider 4, Rider 1 took the quickest route to go call for help. This meant climbing back up to Marble Peak ridge, descending the east slopes to Yule Creek Road and heading down the road to Marble to call for help from the Marble Fire Station. (There is no cell phone service in the Marble area). Riders 2 and 3 stayed with Rider 4 to provide care and CPR.

Rider 1 began his exit at 14:30. He stopped briefly at the Marble fire station but no one was there, so he continued a couple more blocks to Rider 4's house in town and called 911. 911 dispatch received the call at 15:41, about 1 hour and 45 minutes after the avalanche.

During this time Riders 2 and 3 finished excavating Rider 4, who had no pulse and was not breathing. They began CPR. At some point Rider 2 and 3 built a makeshift sled from their gear and moved Rider 4 some 100 feet down valley staying to the riders left side of the valley. By now Rider 2 and 3 were running out of daylight.  Rider 4 was unresponsive, and they felt that it necessary to get out of the valley before temperatures dropped significantly that evening. Egress out of the Raspberry Creek drainage is very challenging and they felt they needed some daylight to make a safe exit. At about 18:00, Riders 2 and 3 made it out of the Raspberry Creek drainage near the old Marble airport landing strip.


Comments

The terrain off of the Marble Peak ridge into Raspberry Creek is committing and exposed. The group made the decision to ride the terrain after several exploratory trips over the preceding seven days. They felt that if they stayed rider's right of the slight gully feature on the more west and southwest aspects, that they could safely ride these lines. Rider 4 ventured furthest left, and this decision resulted in the fatal avalanche. Rider 1 made an extraordinary effort to climb up hill  2,000 vertical feet and then make the 2,000 foot descent into Marble to call for help. Riders 2 and 3 had some hard decisions to make in Raspberry Creek. With nightfall and much colder temperatures imminent they made the hard choice to leave their friend and find their way out of difficult terrain.

The CAIC would like to thank Crested Butte Search and Rescue, the Marble Fire Department, and the Gunnison County Sheriff's Office. These agencies made significant contributions to this report.

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