2023/04/28 - Colorado - King Solomon Mountain, east of Silverton

Published 2023/05/16 by Brian Lazar, Jeremy Yanko - Colorado Avalanche Information Center

The first week of April saw the most prevalent dust deposition event of the season. This dust continued to re-emerge between smaller storm events and became a crust layer that served as a bed surface for storm snow and subsequent wet avalanches. By April 16, warm temperatures and repeated melt-freeze cycles consolidated the snowpack. This pattern continued until additional snowfall returned to the region on the morning of April 24. The snowfall from April 24 to 26 quickly settled and became a reactive storm slab breaking on the “dust-crust” interface.

A fast-moving storm on the evening of April 27 deposited six to eight inches of cold, low-density snow. Moderate to strong northwest winds drifted this snow into small slabs on northeast to east through south-facing slopes above treeline.

A group of four backcountry skiers (Skiers 1 through 4) departed from Silverton on the morning of April 28. They planned to ski the northeast face of point 13045, the northernmost peak of King Solomon Mountain. They scouted the slope with a drone on April 26. They climbed on skis from the Arrastra Creek drainage to the northwest ridge of King Solomon Mountain. The ridge steepens above treeline, and they climbed the rest of the way to point 13045 on foot with crampons.

Skier 1 was slightly higher and skier’s right on the ridge than the other three. He descended first. After his third turn, Skier 1 triggered a very small avalanche in wind-drifted snow (SS-ASu-R1D1.5-I). The avalanche knocked him off his feet and sent him tumbling about 400 vertical feet down the very steep slope before he self-arrested. He scrambled over to a large rock for shelter from any further overhead hazard. He called the others on two-way radios and told them he was uninjured, but had lost both skis in the fall. The skis were stuck upright in the snow about 75 vertical feet above him.  

The group decided that Skier 2 would traverse over to the avalanche bed surface and work his way down to Skier 1. Skier 2 intended to make a slope cut across the 50 to 100 feet of undisturbed snow and trigger any remaining wind-drifted snow.

Skier 2 moved diagonally across the slope. He triggered the avalanche as he crossed a subtle, convex terrain feature between two gullies. The slab initially broke at his feet, but the crack quickly propagated uphill. The avalanche swept him off his feet, over some rocks, and about 1500 feet down the slope. When the avalanche stopped, he was in a seated position, buried to his chest in avalanche debris (partially buried--not critical). His lower leg was seriously injured. He radioed to the rest of the group to alert an organized rescue group.

Skier 3 triggered the SOS function on his Garmin InReach device. Skier 4 called friends in Silverton and provided details to relay to search and rescue. The two then carefully worked down the ridge and entered the slope at a different, lower location when they found a route they felt they could safely navigate. 

The avalanche flowed past, but not over, the rock Skier 1 was sheltering below. He was able to gather one of his and one of Skier 2’s skis and descend to his friend. He helped remove the snow around Skier 2 and began first aid. Skier 1 estimated the debris pile was no more than 3 feet deep and 70 feet wide.

Skiers 3 and 4 arrived. The group assembled a manufactured rescue sled and used that to transport Skier 2 downhill. The terrain and Skier 2's injury made travel slow and difficult. The group stopped moving downhill when they saw search and rescue members approaching. They dug a platform so rescue members could provide more substantial medical care. Search and rescue members transferred Skier 2 to a robust rescue sled and transported him to a waiting helicopter. The helicopter flew Skier 2 to a hospital. Silverton Mountain Rescue and Flight for Life were involved in the rescue.

Slope cutting is a technique for reducing the hazard that involves releasing an avalanche by traveling across the start zone of an avalanche path. It is commonly used by avalanche workers and less frequently by recreationalists (here is a video by Bruce Jamieson that describes why and offers useful advice). Slope cutting is a useful tool, but the number of situations where it can be applied safely is relatively small; where the snowpack, terrain, group, and skill of the cutter are all conducive to this approach. The results can be disastrous if any of these factors is out of alignment. This is why the technique is typically used by teams of avalanche workers, operating in familiar terrain, and as part of a season-long snowpack management program. In this avalanche, the group skied in similar terrain and found small loose-snow avalanches and shallow soft-slab avalanches during the two days preceding the accident. On the day of the accident, Skier 1 triggered a soft-slab avalanche that was small, but large enough to carry him down the slope. Skier 2 then attempted a slope cut, in challenging terrain with little room for error. He underestimated the difficulty of cutting this slope and the size of the avalanche that would release. Once caught, it would have been very challenging to get out as the slide accelerated down the path. 

The group responded effectively to the accident. Their two-way radios allowed for quick and clear communications in the wake of both avalanches. Their satellite communication devices and cell phones allowed them to immediately initiate an emergency response. Their first aid equipment and emergency rescue sled allowed them to provide critical treatment to a severe lower leg injury and begin evacuating Skier 2. Their response decreased the time it took to get Skier 2 to advanced medical care with the help of emergency response personnel. 

This incident is an example of how small avalanches, or even a slip, can lead to serious consequences in very steep and rocky terrain. A similar set of circumstances led to a fatal accident in the Gore Range in April of 2020.