Accident Report

Shrine Mountain, West of Vail Pass - CO

1 snowmobiler caught, fully buried, and injured - 2025/02/17
Lat: 39.5301034, Lon: -106.2516644
Backcountry Area: Vail & Summit County
Status: Final Report
Published: 2025/02/24
Authors: Jason Konigsberg, Mike Cooperstein, Ethan Greene - Colorado Avalanche Information Center

Avalanche

This avalanche occurred on the east face of Shrine Mountain, west of Vail Pass, in an area locally known as Shrine Bowl. It was a soft slab avalanche unintentionally triggered by a snowmobiler. The avalanche was medium-sized relative to the path and large enough to bury, injure, or kill a person. The avalanche broke on faceted crystals near the ground. It was approximately 2 to 4 feet deep and 550 feet wide. It ran around 350 vertical feet (SS-AMu-R3-D2-G).

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Date # Elev Asp Type Trig SizeR SizeD Problem Type
02/17/2025
1 TL E SS AM/u R3 D2 Persistent Slab

Avalanche Forecast

The Colorado Avalanche Information Center’s (CAIC) forecast for the area around Vail Pass for February 17, 2025, rated the avalanche danger at HIGH (Level 4 of 5). An Avalanche Warning was in place. There were two avalanche problems listed. The first problem was Persistent Slab avalanches on northwest through north to east aspects. The likelihood was Likely, and the expected size was Large to Very Large (up to D3). The second problem was Storm Slab avalanches. It was highlighted on all aspects and at all elevations. The likelihood was Very Likely, and the expected size was Small to Large (up to D2). The summary statement read:

"An Avalanche Warning is in effect for the Summit area. Heavy snow and strong winds will create very dangerous avalanche conditions starting early Monday and lasting through Tuesday. Large avalanches will be easy to trigger, and some could release naturally. You can trigger avalanches in the new snow large enough to bury you. Some avalanches will break deeper in the snowpack, propagating broader and larger than expected. You could trigger an avalanche from a distance or below. Travel in avalanche terrain is not recommended during this time."

Accident Details

Pertinent Weather & Snowpack

CAIC forecasters conducted fieldwork in the area on January 6, 2025. They noted a large avalanche in Shrine Bowl on the slope that would avalanche on February 17. The January avalanche left only a thin layer of snow on the ground. At the end of January, dry weather transformed the remaining snow into weak faceted crystals. A storm between February 13 and February 17 brought 2 to 3 feet of snow and strong winds to the Vail Pass area. This combination built a thick, dense snow slab on top of the weak snow near the ground. This setup of a strong snow slab over a weak layer was especially pronounced below east-facing (leeward) ridgelines.

Events Leading to the Accident

Riders 1 and 2 met at the parking lot at Vail Pass Winter Recreation Area at 8:30 AM on the morning of February 17. They had ridden together three times before. They discussed their plan for the day and confirmed that the avalanche airbags they both were wearing were armed. They did not discuss other avalanche safety equipment or check their avalanche rescue transceivers.

They spent several hours riding in relatively flat terrain near Shrine and Ptarmigan Passes before riding toward the north end of Shrine Bowl.

Accident Summary Both riders were traveling near the bottom of a steep east-facing slope on the north end of Shrine Bowl. Rider 2 was uphill of Rider 1 on a steeper portion of the slope. Rider 1 stopped to let Rider 2 descend. Rider 1’s snowmobile sunk into the snow as he stopped. Rider 2 continued across the slope to avoid Rider 1. Rider 1 hit the throttle and wiggled his sled to try to get his sled back to the surface. He was hit by an avalanche from behind. Rider 2 looped around to check on Rider 1, but he was gone. All Rider 2 saw was the avalanche debris and no sign of Rider 1.
Rescue Summary

Rider 2 went back to the last place he had seen Rider 1 and turned his avalanche rescue transceiver to search. He did not pick up a signal. At 12:10 PM he used his cell phone to call 911. He took out his probe pole and spot-probed likely burial points while he waited for help.

Members of the Summit County Sherriff’s Office (SCSO) and the Summit County Rescue Group (SCRG) responded to the request for help. A Special Operations Unit Deputy Sheriff arrived at the Vail Pass Rest Area at approximately 12:30 PM. A Summit County Rescue Group (SCRG) volunteer was in the parking area preparing to go backcountry skiing when he received the notification about the accident. The two rescuers snowmobiled 2.5 miles to the accident site, arriving at the toe of the avalanche at 1:08 PM. The deputy began searching with his avalanche rescue transceiver but did not get a signal. The SCRG rescuer was walking over to interview Rider 2 when he noticed a small piece of orange fabric, no bigger than the size of a tennis ball, sticking out of the snow. He dug in the snow and realized it was the inflated airbag from Rider 1’s avalanche airbag pack. The SAR volunteer, deputy, and Rider 2 dug in the snow and hit Rider 1’s helmet with a shovel. They removed the snow from around the front of Rider 1’s helmet and he began to talk to the rescuers. He had been buried for just over an hour. Other rescuers reached the accident site and provided care for Rider 1. They transported him back to the parking lot and transferred him to an ambulance, which took him to a hospital.

Comments

We do our best to describe avalanche accidents to help the people involved, and the community as a whole better understand them. We offer the following comments in the hope that they will help people avoid future avalanche accidents.

On the day of the accident, Rider 1 forgot his avalanche rescue transceiver at home. The two did not check their transceivers at the trailhead or discuss if not having this piece of equipment would impact their plans for the day. The two did check their avalanche airbags, which likely contributed to Rider 1’s survival. This accident highlights the importance of checking your equipment at the trailhead before heading into the backcountry.

Avalanche airbag packs are an important piece of avalanche safety equipment and can increase your chance of survival (by 44%); however, they do not guarantee your survival. Twenty-nine percent of the people killed in Colorado in an avalanche died from a traumatic injury they sustained in the avalanche. Airbags can fail to inflate when you need them for a variety of reasons (see the first citation in this paragraph). You can also still get buried with an inflated airbag as was the case in this accident. While carrying an avalanche airbag is a great idea, you should also have a device that allows people to find you if you get buried in the debris. The best way to “be searchable” is to wear an avalanche rescue transceiver. In most cases, digging someone out of avalanche debris is the most time-consuming part of the rescue, so you should also carry an avalanche probe and shovel every time you enter avalanche terrain.

Rider 1 survived under the snow for about an hour, which is unusual. Your chances of living longer than 1 hour under the snow are less than 25% and maybe less than 10%. The three most common mechanisms for death in an avalanche are traumatic injury in the ride, asphyxiation in the debris, and hypothermia. Rider 1’s survival is likely due to the combination of a few factors and we can think about these issues in conjunction with these three mechanisms. Trauma: Rider 1 did not sustain a life-threatening injury in the avalanche. His ride in the avalanche was not violent enough to injure him and the debris did not push him into trees, rocks, or over a cliff. Asphysia: Rider 1’s airway was not obstructed and he had enough of an air pocket in the debris to breathe for over an hour. There are a few factors that likely contributed to this. First, the debris was relatively soft and uncompacted. Second, he wore a snowcross helmet that kept snow from packing into his mouth and nose. Third, he was buried on his side facing downhill with his inflated airbag uphill of his head, which limited snow compaction around his head. Hypothermia: Although Riders 1 and 2 needed help from an outside rescue group, the rescue was fast and efficient. The Summit County Sheriff’s Office and Summit County Rescue Group reached the accident site within an hour of the 911 call. They quickly resolved a potentially difficult rescue scenario, provided critical care, and brought the riders out of the backcountry. The rescue team’s effort certainly played an important role in the positive outcome. This could have easily been a fatal avalanche accident.

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