The avalanche occurred on an upper-elevation, north-easterly facing slope west of Lamoille Lake. It was unintentionally triggered by a snowbiker. It was medium-sized relative to the path and produced enough force to bury, injure, or kill a person and break a few trees. The avalanche broke several feet deep and approximately 90 feet wide (SS-AMu-R3-D2). It occurred on an upper elevation, rocky slope at 9965 feet, which is exposed to the wind.

There is no Avalanche Center for the Ruby Mountains.

Pertinent Weather & Snowpack

Observers in the Ruby Mountains reported that the first measurable snow for the winter fell in mid-November. This was followed by almost a month with only around 6 inches of total snowfall. A high-pressure system in mid-December brought high temperatures above 50 degrees at 8051 feet. Snowfall began on December 24th, and up to 48 inches of snow fell between December 24th and the 28th; strong winds accompanied this snowfall. SNOTEL Lamoille #3, 3 miles north of the accident site at 8051 feet elevation, saw SWE increase 1.8” in the time period and was 156% of normal for the water year. The high temperature was 42 F on the day of the accident. Observers reported standing puddles of water at the Thompson Creek Campground (2200’ below the site) on the day of the accident.

Accident Summary Riders 1,2,3, and 4 left from the Roads End Trailhead for a day of motorized snowbiking. They all wore avalanche transceivers and airbags and carried radios and rescue equipment. There is no avalanche forecast center in the Ruby Mountains; however, the group discussed avalanche conditions and agreed to space out and stick to riding low-angled slopes.

At approximately 11:00 AM, the group was riding in the Dollar Lakes area, where several other motorized groups were also recreating. Rider 2 crossed the slope first, followed by Rider 1, approximately 150 yards behind. The group observed an avalanche release above the riders.

Rescue Summary

Initially, the group was not alarmed, as the avalanche appeared small with no significant powder cloud. However, Rider 2 quickly radioed that they could not see Rider 1. The group, along with other nearby snowmobilers, mobilized to search for Rider 1. After initial confusion with avalanche transceiver signals, the group began to turn off snowmobiles, cellular phones, and any other device that may cause avalanche transceiver interference. A group of two rescuers was probing near the partially buried snowbike and located Rider 1 approximately 15 yards downhill. At the same time, a beacon pinpoint search indicated their burial location. A GPS satellite device was used to notify emergency responders of the incident. Due to snowfall and gusty winds, emergency responders had to approach the site on foot or by snowmobile.

Rider 1 was found buried approximately two feet deep and was unresponsive when removed from the debris. Their airbag was not deployed. Rescuers immediately initiated CPR. The Elko County Sheriff's Office Search and Rescue team members equipped with an AED and rescue sled were brought to the site via snowmobile. Rider 1 was transferred to the rescue sled and transported to a flat area, where they were loaded into a tracked UTV for evacuation to the trailhead.

Comments

All the fatal avalanche accidents we investigate are tragic events. We do our best to describe each accident 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.

The group was well-prepared, carried rescue and communication devices, and wore airbags. They discussed current conditions at the trailhead and planned to minimize their risk by traveling one at a time and sticking to low-angled slopes. As weather patterns shift and storms approach your area, it's crucial to scale back your objectives until you've had the opportunity to assess how the snowpack is adapting to new snow loads. While areas with dedicated Avalanche Centers benefit from regular forecasts throughout the winter, the ultimate responsibility for slope-scale decisions lies with you and your group, regardless of location. Dialing back your objectives in snow conditions where you have high uncertainty, such as after recent snowfall and wind events, includes not only avoiding traveling on steep slopes but also giving yourself a wide buffer from steep slopes above.

The rescue operation quickly became chaotic when eight nearby riders joined to assist the group. There was significant delay and confusion as rescuers attempted to switch avalanche transceivers to search mode. This highlights the importance of regular practice with safety equipment to ensure its use becomes second nature in emergencies. Given the inherently high-stress nature of avalanche accidents, the use of rescue equipment should be instinctive. While practicing rescue skills is crucial, it's equally important to familiarize yourself with your airbag. Make it a habit to ride with your trigger accessible and practice deploying the airbag as frequently as you practice with your beacon. These skills can significantly improve response time if caught in an avalanche, thereby increasing your chances of survival.

Assigning the person with the most avalanche experience to lead the avalanche rescue can save crucial time. A leader can ensure all rescuers have their avalanche transceivers switched to search mode and identify and remove any devices or machines that may interfere with the signal from the accident site. Assigning a leader can minimize confusion and prevent duplication of efforts.

Electronic devices such as mobile phones, snowmobiles, heated clothing, and motion cameras can disrupt the signals of avalanche transceivers, potentially compromising their ability to accurately send or receive signals. Minimize this interference by turning off all non-essential electronic devices during a rescue and keeping necessary devices at least 20 cm away from transceivers in search mode. Regular practice with your transceiver in various conditions and potential interference scenarios will help you understand its performance limitations and adjust your search strategy accordingly during an actual rescue.