Observer Name

UAC Staff

Observation Date

Avalanche Date

Region

Salt Lake » Big Cottonwood Canyon » Gobblers Knob

Location Name or Route

Gobbler's Knob - Whitesnake

Elevation

10,000'

Aspect

South

Trigger

Skier

Trigger: additional info

Unintentionally Triggered

Avalanche Type

Soft Slab

Avalanche Problem

Persistent Weak Layer

Weak Layer

Facets

Depth

18"

Width

600'

Vertical

1,250'

Carried

2

Caught

2

Buried - Partly

1

Buried - Fully

1

Injured

1

Killed

1

Accident and Rescue Summary

Two skiers, a 50 year old male (Tyson Bradley) working as lead guide and a 49 year old client (Douglas Green), were backcountry skiing in the Mill A drainage of Big Cottonwood Canyon. They were part of a group of 8 containing 3 guides and 5 clients who ascended Gobbler's ridge via Baker pass. They observed a size 2.5 (destructive scale) natural avalanche from the previous day on an east facing slope on Mt. Raymond but no cracking, collapsing or other signs of instability on the day of the accident.

Bradley and one client descended a south facing avalanche path west of and adjacent to the path of the fatal avalanche. After this run the client left the area because he had a meeting in town at 12:30 p.m. They skied the slope without incident while the rest of the group skied a north westerly facing, treed slope known as the “Benign Line.”

After the first run Bradley re-ascended the ridge and approached the top of the run called Whitesnake. He was joined by three others, one of whom was Douglas Green, and an apprentice guide. The third guide and one other client skied the “Benign Line” again.

Bradley dropped into the Whitesnake path, made a few ski cuts, and stopped 300' downhill at an island of safety on skier’s right about a foot above and to the side of where the avalanche released (see photo). He directed Green to ski to him. The apprentice guide and the other two clients remained at the top of the run. After regrouping, Bradley began skiing again and directed Green to remain where they had stopped. While skiing the next section, the guide felt the slope collapse (which is the weak layer failing just before the avalanche releases). At the same time he noticed Green had started skiing as well. The apprentice guide and the other two clients remained at the top of the run.

Bradley was caught in the avalanche but continued moving right. He impacted a tree and was pushed upward by the avalanche but not carried downhill. He was partially buried and sustained minor injuries. Green was carried downhill and fully buried. He inflated his avalanche air-bag backpack at some point during the avalanche.

After extricating himself from avalanche debris, Bradley skied down the scoured avalanche path and around an exposed rock band where he triggered a small avalanche. He started a beacon search at the edge of the avalanche debris. After covering several hundred yards of debris, he acquired the Green’s signal. His beacon indicated a distance of 77 meters. At the burial location the smallest distance displayed by his beacon was 0.9 meters. He pinpointed Green’s exact location with an avalanche probe.

Green was fully buried on his side with his head approximately 3 feet deep and his body approximately 4-5 feet. His avalanche airbag was inflated. Maximum debris depth was 15 feet. Bradley dug him out of the debris and began CPR. He could not find a pulse. The apprentice guide and two other skiers arrived about a minute after Bradley began digging. They assisted in the exhausting work of digging Green out of the debris. The avalanche was reported at 14:30 to Alta Central Dispatch by the third guide. A medical helicopter landed and evacuated both the Bradley and Green to a hospital in Salt Lake City where Green was pronounced deceased.

The enormous debris pile snapped aspen trees and covered the terrain trap gully below the avalanche path for hundreds of yards. There was no stauchwall or lower boundary of the avalanche because the slab covering the entire slope released, creating an enormous amount of avalanche debris. The avalanche - estimated at 1-2' deep and 600' wide, pulled down every bit of snow between the starting zone near the ridge at 10,000' and well into the gulley at 9000'. The alpha angle, the angle from the toe of the debris to the crown, was 22 degrees.

The Utah Avalanche Center rated the avalanche danger in this terrain as Considerable and had issued an Avalanche Warning on January 21, 2016. See danger rose and bottom line below from that day’s advisory.

“There [are] many weak layers and issues that will cause avalanches today. All the red flags are present. Widespread recent avalanche activity both natural and human triggered, recent snow and strong winds, widespread faceted layers in the snowpack, and today will have strong sunshine and temperatures possibly going above freezing. All these factors combine to make very dangerous avalanche conditions and a HIGH avalanche danger.”

The full advisory from that day can be found at: