Avalanche Danger Is Ongoing

Summer is nearly here, but the threat of avalanche lingers in many Western mountain ranges where it’s been an unusual season for one of nature’s more unpredictable phenomena.

Since late October, 27 people have died in the United States in avalanches, which is about average. What’s unusual is that two deaths occurred in developed ski areas, including in May in Colorado and another in January when a teenager was swept off a ski lift near Las Vegas.

In the previous 19 years, just three of the 416 known avalanche deaths in the nation -- less than 1% -- occurred within ski areas, according to the National Avalanche Center, in part because operators patrol their slopes.

“We at Squaw Valley have a group of us ... if it’s a beautiful day or if it’s a storm day, we communicate before we send anybody up onto the hill,” said Jimmy King, mountain manager at Squaw Valley USA.

On a stormy day -- and winds can hit 150 mph at the resort on Lake Tahoe’s California side -- workers start at the top with explosives to break up cornices and slabs of snow that fall harmlessly down the slopes.

“If I’ve got even just one single patroller that goes up there and says, ‘I’ve got a problem, I don’t like it,’ we stop. We don’t open to the public,” King said.

Last month’s slide at Arapahoe Basin near Breckenridge, Colo., occurred in the morning, when snow usually is more stable. But in this case, warm overnight temperatures had melted the snowpack, creating heavy wet slabs of snow, according to Scott Toepfer of the Colorado Avalanche Information Center.

In southern Nevada, an expert said there may have been no way to predict the slide that killed a 13-year-old snowboarder at Mt. Charleston.

“When this avalanche released, it was unprecedented,” said Doug Abromeit, director of the U.S. Forest Service’s National Avalanche Center in Ketchum, Idaho, who investigated the slide.

While forecasting avalanches is nearly as unlikely as predicting an earthquake, there are conditions that accompany slides, said Bruce Tremper, director of the U.S. Forest Service Avalanche Center in Salt Lake City.

Almost all avalanches occur on slopes of 35 to 45 degrees and are most likely after a heavy snowfall is followed by clear weather that lets ice crystals form, producing an unstable layer below the next heavy snow.

Wind also forms drifts and cornices that are avalanche-prone.

While most avalanches occur from late fall through early spring, two climbers were killed in an avalanche on Mt. Rainier a year ago. Two years earlier, three climbers perished in a June slide at Alaska’s Denali National Park. A Colorado slide killed a climber July 5, 1997.

Tremper himself is no stranger to swimming through tons of snow. In November 1978, the then-24-year-old former national circuit ski racer was working at Montana’s Bridger Bowl ski area.

“I was skiing alone (first mistake) and not even wearing a beacon (second mistake),” he writes. “Even in my ignorance, I could see that it was hardly a subtle situation. Over a foot of new snow had fallen the night before and it was blowing hard, loading up the step slopes

“I had no idea how quickly the slab can pick up after it shatters like a pane of glass.... Then it was like someone pulled the rug out from under me and I instantly flopped down onto the snow.

“I jumped to my feet and tried to build up my speed again so I could jet off to the side. But the blocks (of snow) were moving all around me, like skiing on tumbling cardboard boxes, and nothing seemed to work.”

Moving downhill about 20 mph, he managed to grab a small tree, but it snapped off. Then the tumbling started.

“My hat and mittens were quickly ripped off along with my skis. Snow went everywhere, down my neck, up my sleeves, down my underwear, even under my eyelids.... Every time I opened my mouth to breathe, the avalanche kind of injection-molded my mouth and throat full of snow.”

Unlike many avalanche victims, he managed to stay near the surface by swimming until the wave of snow began to slow.

“I decided that day that I wasn’t an avalanche expert, not even close, and that was the real beginning of my avalanche education.”

The deadliest avalanche to sweep through a ski area hit March 31, 1982, at Alpine Meadows, north of Squaw Valley.

Chairlift operator Anna Conrad and her boyfriend had skied to the resort, closed because of avalanche danger. The unstable snowpack let go and crashed through the three-story employee building. Seven people were killed, including Conrad’s boyfriend and Bernie Kingery, the veteran mountain manager.

Conrad, trapped beneath a bank of lockers, was buried under 10 feet of snow for five days. The ordeal cost Conrad her right leg below the knee and the toes on her left foot, but she survived.

“It’s just being aware, staying on top of it,” King said of evaluating storm situations. “We’ll all come up with our ideas, our solutions and look into the past.... Remember what happened at Alpine Meadows.”

Tremper, who spoke at this year’s annual Operation Sierra Storm at Caesars Tahoe, gave some daunting statistics about the power of avalanches -- and the slim odds of surviving one.

* 90% of all avalanches are triggered by the victim or someone with them.

* Outrunning an avalanche is unlikely, unless it’s possible to race perpendicular to the slide; a dry snow avalanche reaches 60-80 mph within five seconds.

* 25% of all victims are beaten to death by tumbling snow, ice, rocks and trees.

* Once a person is buried, survival is usually up to companions because the victim is locked in an icy cell that allows no movement and provides minimal oxygen; exhaled carbon dioxide accumulates to a deadly level in as little as 15 minutes.

* 93% of buried victims survive if they are rescued within 15 minutes, 50% after 30 minutes. After two hours, the efforts shift from rescue to recovery.

Experts advise companions to search relentlessly for 30 minutes before seeking help. If the victim doesn’t have an avalanche beacon, the options are the needle-in-a-haystack approach of probes and, finally, search dogs.

“Dogs are great at finding people who are already dead,” said Knox Williams, director of the Colorado Avalanche Information Center.

Tremper said even dogs’ sensitive noses aren’t likely to find somebody who’s buried more than 6 feet deep.

“If you escape the avalanche, you’re the rescue party. You’ve got to get them out,” Tremper told the gathering of meteorologists at Tahoe.

While the number of U.S. avalanche deaths has hovered around 28 a year over the past decade, Tremper predicted that the total will rise because of improving skiing and riding equipment that lets people go deeper into the backcountry.

He also said that as equipment gets better, the temptation increases to sneak into the untracked powder of the backcountry, which probably is why 93% of all avalanche victims are male.

“Us men,” he said. “Throughout history, we’ve always needed to go out and slay our dragons. A lot of people are going out to slay their backcountry dragons and a lot of them aren’t coming back.”