- Location: Ashcroft- Near Lindley Hut
- State: Colorado
- Date: 2010/02/23
- Summary Description: 1 skier caught, buried, and killed
- Primary Activity: Backcountry Tourer
- Primary Travel Mode: --
- Location Setting: Backcountry
- Caught: 1
- Partially Buried, Non-Critical: 0
- Partially Buried, Critical: 0
- Fully Buried: 1
- Injured: 0
- Killed: 1
- Type: SS
- Trigger: AS - Skier
- Trigger (subcode): u - An unintentional release
- Size - Relative to Path: R3
- Size - Destructive Force: D3
- Sliding Surface: O - Within Old Snow
- Slope Aspect: NW
- Site Elevation: 10600 ft
- Slope Angle: 37 °
- Slope Characteristic: Sparse Trees
Avalanche occurred on a NW and W facing slope with the crown at 11,000 ft. It was 500 ft wide, running a maximum of 400 vertical feet. Crown propagated across both W and NW facing terrain in the start zone and debris flowed through several different tracks into the deposition zone.
Starting on Thursday, the 18th of February, the Aspen area experienced a large winter storm. The first two days dropped lighter snow totals with 5.5 inches of new snow showing up on a mid mountain weather station at Aspen Mountain. This weather station sits at 10,150 ft and is the the closet to the accident site. On Saturday the 20th through Monday the 22nd, the storm increased in intensity bringing another 28.5" of new snow. The storm slowly cleared on the afternoon of the 23rd, the day of the accident, leaving totals of 35 inches of new snow and 2.5 inches of water equivalent.
Avalanche danger forecasted by the Colorado Avalanche Information Center in the Aspen zone was rated HIGH for all aspects and elevations on the 21st and 22nd of February. On the 23rd, danger decreased below treeline to CONSIDERABLE. That day, the forecast noted "The avalanche danger has eased only slightly for today after the weekendâ€™s large cycle of natural avalanches. Conditions are still very dangerous and the isolated large natural avalanches have still run within the last 24 hours. Conservative terrain choices still required for safe travel."
During the early part of the winter of 2009 and 2010, the Aspen zone forecast area had experienced below average snowfall totals and some colder temperatures. This combination of weather factors created a lower snowpack weak layer of facets and depth hoar that was present at the accident site near the Lindley Hut. A period of high pressure and clear skies in the weather during the middle of January also created a thinner weak layer of small faceted snow grains that could be found in the middle of the snowpack at the accident site. This mid January layer would become the initial failure layer of the fatal avalanche. In some places, the avalanche stepped down and failed near the ground in the lower snowpack depth hoar layer. These weak layers were stressed by the significant weight of three feet of new snow on the weekend prior to the accident. The victim unfortunately triggered this tender combination of slab and weak layer from partway up the slope.
Events Leading to the Avalanche
On the afternoon of Tuesday February 23rd, 3 members of a larger group of 6 staying at the Lindley Hut headed out for a short tour on low angled slopes above the hut. The Lindley hut, part of the Braun Hut System, located roughly 4 miles south of the old mining town of Ashcroft and 16 miles south of the town of Aspen.
The group had not intended to ski very much, but were planning to make a few turns and play around on a jump on the lower angled west facing slopes above the hut.
During the afternoon hours of the 23rd, 3 members of the group at the hut were skinning up and skiing down on some lower angled slopes about 1/4 of a mile east of the hut. At the time of the avalanche two members of the group of 3 were standing on flat terrain in the vicinity of a jump built above a small rollover at the bottom of the slope. The victim was last seen skinning uphill on his telemark equipment approximately 150 vertical feet above the jump. The last seen point was near what would eventually become the track of the avalanche in sparse trees on the skiers left side of the avalanche path.
The victims two partners below did not see him trigger the avalanche, so the last seen point and his exact location at the time the avalanche initiated is not known. The victim was found with one ski still on and a climbing skin still attached to that ski. Based on this information, and his last seen point, we suspect that he was still skinning uphill on a slope just over 30 degrees at the time the avalanche started.
The victim was carried around 150 vertical feet down the slope and buried three feet deep in a dense stand of trees.
All three members of this group did own avalanche rescue gear including beacons, shovels, and probes but since they had not planned on skiing very much, they left most of this rescue equipment behind at the hut as they headed out that afternoon. They did carry two shovels with them to help build the jump at the bottom of the slope.
When the avalanche started, one member of the group of two down at the jump grabbed a shovel and headed up towards the debris. Since they knew the victim was not wearing an avalanche beacon at the time he was caught, the initial search included a visual check of the debris for the victim or other clues to his location. The other member of this group returned to the hut to grab further help, backpacks, and rescue gear.
Once the rescue gear was retrieved from the hut and organized, the group probed likely burial areas uphill from trees and in areas of deeper debris for approximately 2.5 hours. They did not find the victim during this search. Partway through the groups rescue effort, one person from the hut skied out towards Ashcroft to find a phone and contact the sheriffs office.
Early the next morning, 18 members of Mountain Rescue Aspen along with 3 rescue dogs, where flown into the site to help find the victim. He was located by an alert from one of the dogs after about 1 hour of searching. He was found in a dense stand of trees near the toe of the avalanche debris.
Figure 4: Profile of the flank of the avalanche about 1/2 way up the path.