SALT LAKE CITY (ABC4) – Avalanches are one of the most terrifying events in nature. The snow, sometimes silent and sometimes roaring with rushing air and cracking trees, can bring new levels of primal fear, let alone the death and destruction they can leave behind.
With Utah’s canyons being favorites for recreation, avalanche danger is deadly in the winter. For example, the road in Little Cottonwood Canyon, 57% of the 9 miles, are in avalanche runout zones.
That’s why crews work constantly on avalanche mitigation.
Utah, specifically Little Cottonwood Canyon, is the birthplace of avalanche forecasting and mitigation in North America.
According to the Central Wasatch Commission (CWC), It all started in 1938 when the Alta Ski Area operated on a special permit. Authorities realized avalanches were a danger. In 1939 they hired Doug Wadsworth as the first Forest Service Snow Ranger. He was tasked with minimizing avalanche safety hazards on SR210.
CWC says, “Wadsworth created the first avalanche safety rules in North America for skiers and people traveling on the Little Cottonwood Canyon Road. These rules stated that people should stay out of Little Cottonwood Canyon for a few days during and after storms, to keep off of or under steep slopes with no trees after a storm, and not to park under avalanche paths.”
Now, crews from both UDOT and the ski resorts coordinate to mitigate and control avalanche dangers.
According to one of the Avalanche Forecaster’s for UDOT’s Avalanche Safety program, Mark Saurer, “Our goal is to create little avalanches while the roads are closed to prevent larger natural avalanches.”
How do they do it? Mitigation crews cause smaller avalanches using three devices, RACs (Remote Avalanche Control Systems), and a device invented in California called the “Avalauncher,” and good old fashion military Howitzers from the 1950s.
Crews try to work often at first light to knock down the danger areas.
UDOT Region Two District Engineer Shawn Lambert says: “The Howitzers are used for avalanche mitigation primarily and most frequently in Little Cottonwood Canyon, but also in Provo Canyon and Big Cottonwood Canyon. They are used when avalanche conditions present a potential hazard to the roadway and the traveling public. These assessments are made by our crew of experts on the UDOT avalanche crew. The howitzers are used to mitigate avalanche paths in several areas throughout the upper and mid canyon.”
The Howitzer was first used in 1946. the USFS hired a veteran named Monty Atwater (later the inventor of the “avalauncher,” and he was the first person to work with military artillery for avalanche control.
Saurer says two permanently mounted avalanche guns are in Little Cottonwood Canyon, One at Alta and one at Snowbird. But two more are owned by the ski resorts.
The guns can hit targets 3000 to 4000 yards away, giving the avalanche mitigation team the ability to try and trigger small avalanches for about 6 miles of the 9-mile canyon road.
The CWC says that Utah is the only place in the entire country where military artillery is fired over an inhabited civilian area. New systems are coming online, but sometimes the big guns are the best weapon to fight avalanches.
According to Saurer, by using the new RACs system, they have been able to stop shooting over 75% of the populated areas. They do not shoot military artillery over the town of Alta anymore.
Here is an example filmed by UDOT’s Avalanche Safety’s Mark Saurer of an avalanche being triggered at East Hellgate. This avalanche was triggered with both the road and backcountry area closed.
A report at Ski Utah says before avalanche mitigation, “the town of Alta itself was destroyed multiple times by historic avalanches. Lives were lost, and catastrophic damage to structures was a regular occurrence.”
Now, when a storm approaches, crews get ready to either start shooting during the storm or at first light.
The targets to trigger the danger areas are known, and even though they are using 1950’s technology, the gun’s dial-in targeting is preset, so crews know exactly where they are shooting.
When a big storm approaches, everything is planned and prepped. At the time of publishing this report, crews were preparing for a four-day storm cycle expected to drop a lot of snow in the canyons.
Avalanche mitigation work is there to help keep people and infrastructure safe. Little Cottonwood Canyon presents a particular set of dangers. There is no option to close the canyon and let the snow sit because people live there.
75% of Alta can be in the path of avalanche snow.
Lambert adds, “Roadway closures are initiated by the UDOT Avalanche crew when current avalanche conditions require mitigation. Road closures in Little Cottonwood Canyon are done in coordination with the ski resorts, the Town of Alta, Unified Police Department, and the US Forest Service. The roadway closure is carried out by the Town of Alta Police, Unified Police, and UDOT road crews. Once the roadway has been cleared of traffic, the avalanche crew performs mitigation on any slide paths that present a hazard. Following the avalanche mitigation, the conditions are assessed again before opening the road to traffic. Roadway closure information is communicated through the UDOT Cottonwood Canyons website and the UDOT Traffic app.”
Saurer ‘the big difference between what UDOT does and the ski areas do is they focus on keeping the roads safe, not on keeping backcountry areas safe to ski.
For the latest backcountry safety information follow Utah Avalanche Center.