Accident Report Forest Service Utah Avalanche Center

Saturday, December 12, 2004

Snowmobiler Fatality upper Trout Creek near Strawberry – Uinta Mountains

Provisional report by Craig Gordon

Location:

Uinta Mountains, Strawberry area, Upper Trout Creek, GPS 40.17.384 N, 111.06.970 W

Click HERE for photos.

Accident Summary:

Two males had been snowmobiling in the upper Trout Creek drainage. They decided to go to a slope very familiar to them. At around 11:30 they arrived at the base of the slope. They decided the more experienced of the two, who was wearing a beacon and did have a shovel, would attempt to climb the slope first. About mid way up, he got his machine stuck. He worked on it for a while, got hot and took off his helmet. While he was trying to get unstuck his partner, who had no rescue gear, climbed an adjacent slope. His intention was to get high enough on the slope in order to ride down to the stuck machine and assist in the excavation. As the witness got to the top of a bench he saw the crown start to propagate on the same slope the victim was on. The witness realized a large avalanche had been triggered. He circled back around to find no sign of the victim.

Rescue Summary:

The witness rode his machine to a nearby ridge and called 911. He also flagged down 3 or 4 riders to help him with the search. They followed him back and began probing likely areas with broken branches. The witness then jumped back on his machine and climbed another ridge and flagged down two riders who had beacons, shovels, and probes. They returned to the scene and found the victim within 5-7 minutes after their arrival using their beacons. It took another 7-10 minutes to dig him out. He was buried about 4’ deep, face up, not breathing and CPR was initiated. His machine was buried as well and later located about 60’ downhill.

Avalanche Data:

HS-AM-R5D3-O. It was a large, hard-slab avalanche, averaging 4’ deep (8’ at its deepest), and the crown was ¼ mile wide. The slab was composed of pencil hard, dense new snow and wind-deposited snow. The weak layer was faceted snow and surface hoar that was a result of the November dry spell.

Weather History:

Northern Utah experienced a huge snow storm with very strong winds on December 8^th and 9^th with snow lingering into the morning of the 10^th. This overloaded the buried weak layers and combined with a rapid temperature rise produced widespread avalanche activity in the proceeding days. An avalanche warning was in effect on December 8 – 10 with the danger rating of “extreme” on the 9^th and “high” on the 10th. The day of the accident the avalanche danger was rated as “considerable with deadly consequences.”

Considerable means that human triggered avalanches are probable.