CAIC: Colorado Avalanche Information Center

2021/01/08 - Utah - Dutch Draw, Park City Ridgeline

Published 2021/01/11 by Staff - Utah Avalanche Center


Avalanche Details

  • Location: Dutch Draw, Park City Ridgeline
  • State: Utah
  • Date: 2021/01/08
  • Time: Unknown
  • Summary Description: 1 sidecountry rider caught, buried, and killed
  • Primary Activity: Sidecountry Rider
  • Primary Travel Mode: Snowboard
  • Location Setting: Accessed BC from Ski Area

Number

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

Avalanche

  • Type: SS
  • Trigger: AR - Snowboarder
  • Trigger (subcode): u - An unintentional release
  • Size - Relative to Path: R2
  • Size - Destructive Force: D2
  • Sliding Surface: O - Within Old Snow

Site

  • Slope Aspect: E
  • Site Elevation: 9800 ft
  • Slope Angle: 39 °
  • Slope Characteristic: --

Avalanche Comments

Classification for this avalanche is SS-AS/AR-R2-D2-O

Avalanche crown slope angle: 39 degrees

Avalanche Width: 150 feet

Avalanche Length: 600 feet

Alpha angle: 32 degrees

The vertical drop of the avalanche was approximately 400 feet. The snowboarder was carried approximately 200 vertical feet.

On the day of the accident, the avalanche danger was rated CONSIDERABLE on the slope where this avalanche occurred.

Weather Summary

On the day of the accident, skies were partly cloudy, winds were generally light and westerly, and temperatures were in the mid-20s F.

In the week leading up to the accident, there were two small storms, and many human triggered avalanches in the area. Storm 1 on January 3rd brought 1-4 inches of new snow and moderate winds out of the southwest at upper elevations. The following day on January 4th, a human-triggered avalanche occurred about 2 miles north of the 9990 chairlift in the backcountry on a slope called Sound of Music, an east aspect at 9,200'. Storm 2 on January 5th brought 8-10 inches of new snow (containing 0.75 - 0.9 inches of water) with moderate to strong westerly winds. That day, 10 human-triggered avalanches were reported to the UAC. On January 6th and 7th, nine human triggered avalanches continue to be reported. Almost all activity involved avalanches failing in weak, faceted snow now buried 1-2.5 feet deep.

Snowpack Summary

We dug a snowpit on a safe representative slope nearby and found a snowpack structure that has been seen widespread across the Park City Ridgeline. The layers shown in our snowpit profile were similar to the ones in the crown of the avalanche.

The layer of concern is a varying thickness layer of facets sitting on top of a melt-freeze crust that likely formed during the end of November and the beginning of December. This facet crust interface has been seen widespread across the Park City Ridgeline. The avalanche failed within the weak facets sitting atop the supportable melt-freeze crust. The avalanche initially failed mid-slab in some places, stepping down to the melt-freeze crust, but did not step all the way into the facets at the ground in any places on the crown or slide path.

Accident Summary

A 31-year-old male snowboarder from Clinton, Utah, was killed in an avalanche in Dutch Draw area off of Silver Peak. The snowboarder was riding with a skier, and neither of them was carrying any avalanche rescue gear. The pair was riding in the Canyons Village area of the Park City Mountain Resort, where they took four chair lift rides, ultimately bringing them to the top of the 9990 chairlift around 9:40 a.m. They hiked a short distance to access the Dutch Draw area at the top of the chairlift via the backcountry exit gate. From this gate, they left the ski area boundary, entered into the backcountry, and followed a ridgeline to the top of Silver Peak.

At the top of the Silver Peak, the rider began his descent of a slope called Conehead. When the snowboarder was midway down the slope, the skier started her descent. After making two turns, the avalanche broke at her feet, and the snowboarder was still midway down the slope where he was caught, carried, buried, and died from the avalanche. The skier was not caught in the avalanche.

Other avalanches along the Park City Ridgeline in the last week have been triggered remotely from ridegtops while others have been triggered by people low on slopes. It cannot be determined how this avalanche was triggered. It is likely that this avalanche was triggered by at least one of the two people on the slope or possibly by both.

Rescue Summary

The skier who was not caught in the avalanche called 911 at 10:09 a.m. and 911 dispatch notified PCMR patrol, who then requested air support. In addition to the skier, there was a party of two and a party of one who had been riding in the area. Helicopters from the Utah Department of Public Safety (DPS) and AirMed responded. A helicopter from Lifeflight was also in the air and available if needed. The skier was transported from the scene via the DPS helicopter, and the other three people left on foot. Once the scene was clear, explosives were dropped from the DPS helicopter and triggered one avalanche to the looker’s right of the original avalanche.

Following the explosive work to make the scene safe from additional avalanches, rescue personnel from Summit County Search and Rescue, Park City Mountain Ski Patrol, the Park City Fire District, and Wasatch Backcountry Rescue arrived on the scene. An initial search was done with avalanche transceivers and a RECCO detector, but the snowboarder was found with an avalanche rescue dog. He was buried 2 feet deep and dug out of the debris at 2:30 p.m. His snowboard was still attached to one foot while his other foot had been pulled out of his boot. No obvious signs of significant trauma were reported.

Media

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Snowpits

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Figure 14: Snowpit profile below. The red line indicates the weak layer on which the avalanche fractured.