At midday on December 15, Rider 1 and Skier 2, a married couple and Crested Butte residents, left for a short tour. Rider 1 traveled on a splitboard, while Skier 2 was on lightweight touring skis. Since their plan was to ski up and descend the snow-covered Snodgrass Road, with no exposure to avalanche terrain, they chose not to bring their avalanche rescue equipment.

At the top of the road, they changed plans and decided to descend much steeper terrain off Snodgrass Mountain to the north. A friend had traveled off the north side the day prior and reported great conditions. The couple recognized they were ill-equipped for travel in avalanche terrain, but they proceeded.

From near the summit, they descended a steep, forested slope. Travel through the weak, faceted snowpack was difficult, and they hit many rocks and stumps. They descended about 1,000 vertical feet and arrived at the top of an open slope around 10,000 feet in elevation. Skier 2 watched while Rider 1 descended first. He made one turn and the slope avalanched. He was pulled into the flowing snow, and Skier 2 quickly lost sight of him.

The avalanche flowed through a band of small trees. Rider 1 was slammed into a four- to five-inch-diameter tree, and the impact broke his leg. Rider 1 was wrapped around the tree, unburied, and alert when the avalanche stopped.

Skier 2 followed her husband’s track onto the bed surface of the avalanche and carefully switchbacked down until she heard him call out and skied straight to his position lower on the slope. He was bleeding significantly and unable to walk. Despite poor cell coverage, Skier 2 was able to place a call to 911 at 2:26 p.m. A medical helicopter was able to land near the toe of the avalanche and pick up Rider 1 at about 4 p.m.

ANALYSIS

The soft slab avalanche broke on a layer of faceted snow capped by a thin layer of surface hoar, and it released broadly: about 300 feet across the full width of this small avalanche path. The extent of propagation for such a soft slab hints at the very weak nature of the snow below it. As the avalanche ran, it scoured most of the snow down to a buried sun crust. Debris piled up to three feet deep.

The Colorado Avalanche Informa- tion Center’s Gunnison zone rated the hazard as Considerable (Level 3 out of 5) near and above treeline, and Moderate (Level 2) below treeline. The CAIC recorded 186 avalanches in the Gunnison zone between December 10 and 14. Seventeen of the avalanches were triggered by people on below-treeline, northeast-facing slopes similar to the accident slope.

This couple made a last-minute decision to enter avalanche terrain without detailed knowledge of the terrain. (Rider 1 had ridden down the north side of Snodgrass three times before, while Skier 2 had not.) After a few minutes of descending, they recognized that they had underestimated the steepness and complexity of the terrain. Reflecting afterward, they described not knowing how to fix the situation they had created. Turning around and skinning to the ridge did not occur to them at the time, but it might have been the best solution.

Rider 1 was not buried and was very lucky that getting caught did not have much worse consequences. It’s a great reminder to always carry avalanche rescue equipment in the winter backcountry. (Source: Colorado Avalanche Information Center.)

Read the full report from Colorado Avalanche Information Center.