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SALT LAKE COUNTY — In the past several days, Utah has seen intense avalanche activity. When a storm cycle like that starts, Little Cottonwood Canyon Road is very vulnerable to slides, and road closures.
Often, powder-hungry skiers and snowboarders head to the mouth of the canyon only to be held up while avalanche crews make the road safe.
"The goal of our program is to recognize when those conditions are approaching, and then close the road and use explosives to bring the avalanches down when the road is closed," explained Chris Covington, an avalanche forecaster for the Utah Department of Transportation.
The goal of our program is to recognize when (avalanche) conditions are approaching, and then close the road and use explosives to bring the avalanches down when the road is closed.
–Chris Covington, avalanche forecaster
Little Cottonwood Canyon Road has the highest avalanche risk of any major road in North America. Covington said it's the riskiest because of the number of cars on the road, the number of times avalanches reach the road, and the amount of road covered when those avalanches come down.
"The combination of how close the avalanche paths are to the road here, and how much snow falls in this canyon, really leads to it having such a high avalanche hazard index," Covington said.
On average, Little Cottonwood Canyon Road closes for parts of 19 days each year. When it does, crews work hard to get it reopened quickly by firing charges from 105 mm Howitzers. The guns were built for the battlefield, but they blast a natural enemy in this canyon.
Ski patrol workers from Alta and Snowbird man the guns, supervised by a UDOT avalanche forecaster. Other UDOT personnel keep an eye on the road while they're blasting the avalanche start zones up near the ridges. Another member of the team keeps an eye on the weather and the incoming snow.
Each year, the crews keep an eye on 35 named avalanche chutes in the upper half of the canyon. Those chutes have historically released slides that can reach the road.
From Feb. 29 through March 4, UDOT shot off 179 artillery rounds and dropped 27 explosive charges from a helicopter, triggering numerous slides.
"The goal of our safety program is to keep knocking down smaller avalanches so we don't let the snow build up, and have one giant avalanche that comes down and buries the road," Covington said.
Last week, as snow storms moved across the Wasatch Front, the avalanche crews kept at it for five days. That meant numerous road closures — two overnight, and one that lasted five hours Sunday afternoon.
"Each 12 hours, as we got more weight on top, we knew more avalanches would occur," Covington said.
From Feb. 29 through March 4, UDOT shot off 179 artillery rounds and dropped 27 explosive charges from a helicopter, triggering numerous slides.
"What we have had is large storms, then large breaks between storms, which kind of makes the snow on the ground very weak and very susceptible to avalanche when more snow piles on top," Covington said.
The crews couldn't trigger an avalanche in Little Pine chute, below the entrance to Snowbird, until the fourth day of their control work. But they finally watched it come down.
"It just feels great to know that the the threatening avalanche paths have had an avalanche, and that the road is safe to open," Covington said.
