CAIC

Avalanche Details

Location: Parrott Peak, La Plata Mountains
State: Colorado
Date: 2022/02/26
Time: 12:17 PM (Estimated)
Summary Description: 1 backcountry skier caught, partially buried, and injured
Primary Activity: Backcountry Tourer
Primary Travel Mode: Ski
Location Setting: Backcountry

Number

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

Avalanche

Type: SS
Trigger: AS - Skier
Trigger (subcode): u - An unintentional release
Size - Relative to Path: R3
Size - Destructive Force: D2.5
Sliding Surface: I - New/Old Interface

Site

Slope Aspect: NE
Site Elevation: 11200 ft
Slope Angle: 38 °
Slope Characteristic: Sparse Trees,Dense Trees,Gully/Couloir

Avalanche Comments

This was a soft slab avalanche triggered by a backcountry skier. The avalanche was medium sized relative to the path and destructive enough to injure, bury, or kill a person. The avalanche broke under recent snow on a 20 cm thick layer of faceted snow (SS-ASu-R3-D2.5-I). The crown face of the avalanche was 24 to 30 inches deep and about 200 feet wide. The avalanche started on a steep, rocky, wind-drifted rollover on a north to northeast-facing slope below treeline. The avalanche ran 1,100 vertical feet through a mixture of dense to sparse trees and into a treed chute. This was a Persistent Slab avalanche. To the east of the skier-triggered avalanche, two avalanches released sympathetically (SS-ASy-R2-D2-I).

Backcountry Avalanche Forecast

The Colorado Avalanche Information Center (CAIC) issued a Special Avalanche Advisory for all mountainous areas of Colorado on February 24 at 5:00 PM, as an Avalanche Warning expired. The Special Advisory was valid through February 27, and the statement read:

You can trigger a large and dangerous avalanche, and natural avalanches are possible. You can trigger an avalanche from below or an adjacent slope. Avalanches can break wider and run further than you might expect. Traveling on or under slopes steeper than about 30 degrees is not recommended.

The CAIC’s forecast for the South San Juan zone rated the avalanche danger as Considerable (Level 3) above, near, and below treeline on the day of the avalanche. The forecast listed Persistent Slab avalanches as the primary problem at all elevations on west through north to southeast-facing slopes, and south-facing slopes above treeline. The likelihood of triggering was Likely and the potential size was Small to Large (up to D2). The summary statement read:

Recent snowfall and wind drifting have built thick slabs above very weak snow layers. Today, winds shift from the southwest to northwest, expanding the distribution of dense, cohesive slabs of snow on easterly and south-facing slopes. Broader drifting could increase a rider’s chance of triggering a large, dangerous avalanche that breaks wide across terrain features or naturally provoke a slide to fail. Avoid smooth, rounded pillows of snow below ridges, in gullies, and respect the warning signs of potential danger like cracking or audible collapses.

Steeper slopes lower in elevation warrant the same avoidance as upper elevations, and a burial on Wolf Creek Pass Friday confirms you don’t need to tickle a wind-drifted slope to get into trouble. Conservative decision-making is crucial. Avalanches can run farther than you might expect, so give yourself a wider buffer than usual below steeper, more extensive terrain to manage the uncertainty of avalanche size.

Weather Summary

The Natural Resources Conservation Service's Columbus Basin SNOTEL site is 6 miles northeast of the accident site at an elevation of 10,785 feet. Snow began accumulating there in mid-October. The snowpack remained shallow through early December. Storms became more frequent from December 9, 2021 to January 1, 2022. During a series of storms starting December 22, the SNOTEL measured a gain of 8 inches of snow water equivalent (SWE). The site recorded 0.3 inches of SWE between January 2 and February 14. Between February 15 and February 25 SWE increased by 2.8 inches.

The CAIC maintains the Lewis Creek weather station 5 miles east-northeast of the accident site. The wind speed was between 15 and 30 mph at the Lewis Creek site between February 15 and 25. The wind direction was from the south, but turned to the southwest at the end of this period. The strongest winds occurred February 22 to 23, with hourly average wind speeds of 25 mph and gusts to 56 mph. Winds turned westerly on February 25 and were 5 to 15 mph with gusts in the 20s. The avalanche was triggered on a northeast facing slope in wind drifted snow.

Snowpack Summary

Snow began to accumulate in the La Plata Mountains in early October, but the snowpack remained shallow and weak through early December. A series of storms from December 23 to January 3 brought significant snowfall to the area and resulted in a widespread avalanche cycle. The remainder of January into mid-February was unusually dry and most of the snowpack below treeline turned into weak, faceted grains.

Snowfall resumed on February 13, bringing the first significant new snow load to the weak faceted snow surface. This new snowfall and strong southwesterly winds caused a spike in avalanche activity, and the CAIC issued an Avalanche Warning and High (Level 4 of 5) danger on February 23 and 24. The CAIC documented 85 avalanches in the South San Juan zone between February 22 and 24 on west to north to east aspects at all elevations. The Avalanche Warning expired at 5:00 PM on February 24, and was replaced with a Special Avalanche Advisory warning about dangerous backcountry avalanche conditions from February 25 to 27.

Events Leading to the Avalanche

On the morning of February 26, Skiers 1 and 2 parked at the winter closure of La Plata County Road 124 north of Mayday and headed into the backcountry for a day of skiing. They made one run on a northeast-facing slope into Snowslide Gulch, directly south of Root Creek. Then they crossed the valley bottom and ascended to a ridge between Snowslide Gulch and Root Creek. They noticed natural avalanches and cracks in the snow that occurred in the previous few days.

On the ridge the pair looked at digital maps and discussed options to ski into Root Creek. Skier 2 suggested descending along the ridgeline above steep slopes. Skier 1 had previous experience in the terrain and mentioned there were lots of trees and no open start zones below the ridge.

Accident Summary

Skier 1 descended several hundred feet down the ridgeline. Skier 2 then descended to join him. Skier 1 began skiing as Skier 2 arrived. Skier 1 went over a steep roll and had made several turns when Skier 2 saw the slope fracture and begin to avalanche. The avalanche occurred at approximately 12:17 PM.

The avalanche started on a steep, tree-covered slope. It carried Skier 1 through the trees into a gully. The avalanche ran 1,100 vertical feet. Skier 1 deployed his avalanche airbag. He was carried past the deepest point of the debris pile and partially buried near the toe of the avalanche.

Rescue Summary

Skier 2 carefully skied onto the bed surface of the avalanche. He searches with his avalanche-rescue transceiver and looked for visual clues while descending the avalanche path. He noticed the avalanche got wider as it traveled downslope. Skier 2 picked up a transceiver signal near the toe of the avalanche debris, then saw Skier 1. Skier 1 was partially buried, with both his legs covered in avalanche debris. They made voice contact.

Skier 2 called 911 at 12:27 PM and then began digging Skier 1’s legs free. Skier 1’s leg was injured and there was lots of blood in the snow. Skier 2 improvised a tourniquet. Worried about additional avalanche hazards, Skier 2 moved Skier 1 downhill to a group of trees. Skier 2 called 911 again at 12:44 PM to provide an update on the severity of Skier 1’s injury.

La Plata County Search and Rescue and Flight for Life responded to the accident. The helicopter flight crew contacted Skier 2 by text message at 1:25 PM and then landed in a meadow several hundred feet downhill from the skiers. The flight crew, pilot, and Skier 2 moved Skier 1 to the helicopter. The helicopter flew Skier 1 to a hospital, then returned to evacuate Skier 2.

Comments

Skier 1 sustained significant injuries in the avalanche. A fast rescue was key to saving his life. Some important elements included:

Skier 2’s initial call to 911
The first-aid Skier 2 provided in the field and the additional information he provided during his second 911 call
The decision by the Flight for Life crew to evacuate Skier 1 rather than bring in additional resources

The avalanche packed snow inside of Skier 1’s clothes. Unable to move, he quickly became cold, and hypothermia would have become an issue of increasing importance had the rescue taken longer.