The History of Avalanche Control in the United States
Updated: Apr 19, 2021
The early dawn boom of avalanche bombs detonating is a common morning alarm clock in many mountain towns around the United States. For many avid skiers, these explosions are welcome sign, reporting the arrival of fresh snow and a powder day ahead. Nonetheless, they also serve to remind us of the unstable, complex, and dangerous nature of recreating in the volatile and hazardous environment of snowy mountains.
The mountains demand not only stoke, but caution and respect. According to Colorado Avalanche Information Center, so far in the 2020-2021 winter season, 35 people in the U.S. have died from avalanches, including 20 skiers and snowboarders. Avalanche knowledge is crucial to the survival of mountain towns, the maintenance of roads and highways, the operation of ski resorts, and the safety of backcountry skiers.
Awareness of avalanches and the huge risks they pose first arose with western expansion in the United States during the 19th century. As pioneers began exploring and settling the West, particularly as part of the mining boom of the mid/late 1800s, they experienced the threat and destruction of avalanche events. Miners quickly developed techniques of building avalanche barriers and splitters to protect their surface facilities.
It was not until the 20th century that the United States government started interesting itself in avalanche mitigation.
Alta: The Birthplace of Avalanche Control
Alta, a ski resort located in Little Cottonwood Canyon, Utah, is the birthplace of avalanche research, forecasting, and control in North America. In 1939, the United States Forest Service (USFS) hired the first ever snow ranger, Douglass Wadsworth to look into mitigating avalanche danger in Little Cottonwood. The canyon had a particularly high avalanche risk because of its steep terrain and large snowfall. The town of Alta itself had been destroyed multiple times in history by severe avalanches and catastrophic damage to town structures and even lost lives were becoming too regular an occurrence.
Wadsworth began developing basic safety protocols to protect travelers and skiers in Little Cottonwood Canyon. This often entailed closing the roads and ski access for days after a storm to allow the snow to settle and natural avalanches to run their course. However, these closures were inconvenient and unpopular, so he also sought to develop techniques for actively reducing avalanche danger. In February 1939, Wadsworth, with the help of Karl Fahrner, then the Director of the Alta Ski School, made the first North American attempt to trigger an avalanche with the use of explosives. While the charge failed, it marks the beginning of a long history of human avalanche mitigation through explosives.
Monty Atwater: The Grandfather of U.S. Avalanche Mitigation
In 1945, as the snow ranger team in Alta was beginning to grow, the USFS hired Monty Atwater. Atwater was a World War 2 veteran of the 10th Mountain Division, a troop specializing in navigation and combat in snowy, mountainous terrain. Atwater had observed European practices of triggering avalanches using military artillery during the war, and brought this expertise to his work at Alta.
In 1949, Atwater arranged for the Utah National Guard to bring 15 rounds of 75mm French Howitzer to Alta, the first use of military artillery for avalanche control in the United States. The artillery allowed the snow rangers to have high accuracy in launching explosives at a far range. This technique of avalanche control was so successful that military artillery became a permanent fixture at Alta.
Nonetheless, despite the efficacy of the military ordinances, this technique also presented many limitations and restrictions. First of all, only army troops were permitted to fire the weapons, often limiting the flexibility of mountain staff to conduct avalanche mitigation, particularly when large snow storms prevented troops from getting to the mountain. Atwater himself was reported to have fired the artillery on several occasions without military permission, a source of tension between the ski patrol force and the military troops. In addition, artillery was a limited resource and supply was bound to run out eventually.
Atwater thus began exploring and perfecting the use of handheld explosives and means of launching them that could replace and supplement the artillery and larger guns. His most famous invention is the Avalauncher, which uses pressurized nitrogen to shoot 1kg explosives up to a few hundred meters. While the accuracy, range, and explosive size capability were inferior to that of the military machines, they required fewer men to operate and, as a civilian tool, less governmental oversight and red tape.
Avalanche Control & Research Beyond Alta
Techniques and practices developed by Atwater and his team at Alta soon spread around the country. Following Alta’s model, the USFS systematically expanded its snow ranger programs to other areas with high avalanche dangers including Berthoud Pass, Colorado and the passes of the Cascades in Washington. Military artillery was installed in various states to mitigate avalanche risks that threatened major highways. Avalaunchers also became widely used as a popular alternative where military artillery was not an option.
The Forest Service also invested institutionally in expanding the field of avalanche research and science. In 1949, the USFS started the Alta Avalanche School, the foundation of what is now known as the National Avalanche School. This academy became a hub of avalanche research where expert scientists could come to exchange the newest information and mitigation techniques. Other important research centers popped up across the country, most notably the U.S. Army’s Snow Ice and Permafrost Research Establishment in New Hampshire and the avalanche research program at Montana State University in Bozeman.
The USFS also sought the advice and expertise of international experts, particularly given that avalanche research in other countries was often more developed than in the United States. The Swiss were the primary pioneers of avalanche awareness, producing research on the physical behavior of snow and the dangers of avalanches as early as 1876. Other countries with notable histories of avalanche research include France, Canada, Norway, Austria, Japan, Iceland and Russia. The USFS and other avalanche research institutions invited researchers, engineers, and experts from these countries to visit the United States’ most avalanche-prone areas and provide consultation on best practices.
The De-Centralization of Avalanche Research
In the late 20th century, the United States Forest Service began to pull back from its involvement in avalanche control. First, beginning in 1972, it began winding down the snow ranger program and declined to be responsible for avalanche mitigation within private ski areas. The resorts and their ski patrols became fully accountable for patrolling their properties.
As a result, local and regional avalanche centers began to grow in strength. These new institutions were also responding to increasing demand for public awareness about avalanche danger. They provided education to local communities and more real-time, location-specific avalanche forecasting.
Today, there are avalanche research centers across the United States at a number of universities and scientific research institutions. The Forest Service National Avalanche Center continues to be a center of American research in this field, also supporting a number of regional centers. While these bodies remain fairly decentralized, they are highly collaborative with national and international colleagues working closely to exchange information and cutting edge technologies.
Progress and Development in Avalanche Research
Developments in avalanche control have occurred in two main areas: understanding of snow properties and weather patterns allowing better forecasting of avalanche events and more precise targeting of avalanche control; and improved safety of delivery systems for explosives through advances in ski equipment, helicopter technology, and stability of explosives.
Early avalanche control was often, in the words of one ski patroller, “putting a bunch of Forcite dynamite sticks together and going out and going, ‘I think we should throw some over here, and I think we should throw some over there.’” In other words, much of the avalanche patrol strategy was based on instinct or past experience, rather than a response to conditions of the moment. Over time, increased knowledge about which kinds of slopes and snow conditions were more likely to produce avalanche events allowed patrollers to hone in on high risk areas and more precisely target their avalanche mitigation.
Improvements in ski gear have also allowed patrollers to traverse further into uncontrolled slopes. While patrollers used to have to wade through waist deep snow in normal shoes or snowshoes, they can now use backcountry skis and skins to more easily navigate newly fallen snow.
The Forefront of Avalanche Control Technology
While there have been improvements in the targeting of avalanche control and the placement of explosives, the actual techniques of avalanche mitigation have not changed much since their development by Montgomery Atwater in the early 1950s. Four principal procedures of avalanche control route setting have dominated the past 7 decades:
Ski cutting: rapidly traversing a slope on skis to initiate an avalanche
Hand charging: hand lighting and throwing an explosive
Avalaunching: using the Avalauncher or another similarly rigged device to launch explosives
Artillery: using military-grade artillery to fire explosives at far range and with high accuracy
The 21st century has seen electronic detonation systems become the new cutting edge of avalanche control research, the first major innovation in the area of avalanche control techniques in decades. This innovation has been driven by a desire to reduce the risk of explosive accidents to ski patrol and to eliminate and replace artillery in avalanche mitigation.
Here are three examples of new electronic detonation systems being employed today:
Gazex
Pressurized oxygen and propane are stored underground. This gas can be mixed and set off by remote control. The shockwave produced collides with the snow surface triggering an avalanche.
Wyssen Towers
Invented in Switzerland, these tall metal towers contain explosive magazine equipment similar to charges thrown by hand that can be activated by remote control. They can be reloaded with explosives by helicopter.
O’Bellx
These egg-shaped cones store oxygen and hydrogen which is detonated remotely. They can be installed, removed, and refilled by helicopter, limiting human handling of explosives, and are very popular because they are low cost and low maintenance.
With the development and installation of remote avalanche mitigation systems, snow safety professionals and outdoor recreators everywhere will benefit from enhanced safety and efficiency. In the words of Dave Richards, Director of Alta’s Avalanche Department, “What it all boils down to is improving the level of safety to the skiing public and the level of safety to my employees.”
While you're here, learn more about the history of skiing.
About the Author
Kyra Whitelaw is a rising senior at Stanford University studying Political Science. Originally from New York City, Kyra has been skiing since she was 3 years old at a variety of resorts on the East coast and out West. She is currently on a gap year and living in Kings Beach, California working as a ski instructor at Northstar.