2020-21 Avalanche Season may Prove the Most Deadly in Decades

The week of Jan. 31- Feb. 6 marked the deadliest week for avalanches in over one hundred years. In total, 14 backcountry riders in the United States died indirectly from avalanches. The previous record was set in 1910 when an avalanche in Washington state swept away two trains in Wellington, killing 96 people.

Fourteen deaths occurred around the country in New Hampshire, Alaska, Montana, California, Colorado and Utah. The incidents were also spread across disciplines other than skiing with a snowmobile fatality in western Montana and three climbers in Alaska. Several states—including Montana—have reported a particularly weak snowpack and increased use of backcountry terrain (most likely caused by the pandemic) as significant contributing factors to the increase in frequency and severity of avalanche fatalities.

“The recipe we have—or the snowpack we have—is a situation that doesn’t happen often; the last time we had a similar snowpack was almost ten years ago,” said Doug Chabot of the Gallatin National Forest Avalanche Center (GNFAC). “We have this really weak snow at the ground, and when we have these situations we’re on pins and needles a lot of the year because we’re trying to figure out how much weight—how much snow—is it gonna take to break this layer at the ground.”

Avalanche forecasters call this situation a “persistent slab problem,” and while it is the least likely of most avalanche situations to slide, it has the greatest potential to create a deadly avalanche if it does. Forecasters attributed the two deadliest incidents in the record-breaking first week of February to persistent weak layers. On Monday, Feb. 1, four skiers were buried (three of whom died) in southwest Colorado after an avalanche broke on a persistent weak layer, burying one of the skiers twenty feet below the surface.

“The four riders worked for hours and only got through the top half of avalanche debris above the victims,” according to a report from the Colorado Avalanche Information Center. “Anyone who has dealt with avalanche debris over a few feet deep will tell you the digging gets more difficult and more complicated the deeper you go. Eventually, it took an organized search and rescue group, with many people and power tools, two days to recover all three riders.”

An analysis of the snowpack anywhere in the Bozeman area would show a similar instability to that experienced by the Colorado skiers. However, the unlikely nature of triggering a large slab avalanche often complicates decision-making for backcountry travelers. While avalanche conditions may decrease as snow piles up and the weak layer strengthens, the possibility of persistent slab avalanches will not disappear, and the resulting slides will only get bigger.

“It’s like walking around a minefield, and you’re like ‘oh there’s only one or two mines in this football field!’” says Chabot. “You can still trigger big avalanches, even though you’re seeing all these tracks, and skiing things where it seems—SEEMS—safe. But the recipe is still there.”

No matter the danger rating, snow on slopes steeper than 30 degrees can slide. A skier in New Hampshire triggered a slide on Monday, Feb. 1 that buried and killed him, despite the avalanche forecast declaring the danger “low.”

“Accidents like this serve as a stark reminder to us all of the role that luck can play in successful outcomes in our backcountry endeavors,” said the Mount Washington Avalanche Center. “Ian Forgays [the skier who died] had many years of experience in this terrain and, according to texts sent on Sunday, planned ‘to move slowly and intentionally’ knowing that some lines there are ‘rowdier than others.’”

So far, 32 backcountry users have died this winter—well over the seasonal average of 27—and the ski season still has a couple of months left (the last reported avalanche in the Bozeman area for the 2019-20 season occurred on June 11 at Fairy Lake where a skier triggered a wet-loose slide). And with more people getting out in the backcountry due to the pandemic, this season has plenty of potential danger left.

“We know there’s more people out there, and we encourage that—I’m excited that more people are getting out in the backcountry and enjoying being outside—but with that comes some crowds,” Chabot said. “With avalanches, a bad snowpack and more people in the backcountry means that there’s more triggers out there… the odds just go up that someone can get caught.”

According to the Friends of Hyalite (a local outdoor advocacy group that tracks usage of Hyalite canyon), a recent count totaled 17,297 vehicles traveling through Hyalite during the month of January—a 67% increase from January 2020.

So far this season only two recreationists have died in Montana as a result of an avalanche. Two snowboarders triggered an avalanche while traveling uphill at Beehive Basin, north of Big Sky. Early season snow followed by dry weather formed a persistent weak layer at the bottom of the snowpack that the two travelers triggered near the top of the ridge. The slide critically injured one of the riders, who died later on from the trauma.

“People tend to think that skinning uphill is pretty safe,” Chabot said. “And for that accident and others around the country, people are getting into avalanche terrain without knowing it. And once they’re in avalanche terrain without knowing it, chances are their partners are in it too… and when an avalanche happens and you have multiple burials, you almost always have multiple fatalities.”

On Saturday, Feb. 6, a group of skiers skinning uphill in Mill Creek Canyon, Utah triggered a major slide, burying six skiers and killing four. The leading party of four remote-triggered an avalanche above them while traversing a steep section of the hill one at a time, burying three of the members plus a party of three following below. One of the four was able to grab a tree and sustain the immense force of the avalanche sweeping over him—an action that usually proves too feeble for an avalanche. He called up to the fifth member of the group who was waiting for them above, and the two skiers located and dug out all six skiers. Only two of the six survived.

“Because they were all skinning uphill, the toe pieces were all likely in the walk or lock position, which would have made it very difficult for the skis to release from their feet,” said the Utah Avalanche Center in a report. “All people [except one] had both skis still attached to their feet when they were buried, which may have contributed to deeper burials.”

While avalanche education does not make backcountry users immune to avalanches, knowing how to recognize and travel through avalanche terrain significantly increases the odds of living to ski another day. For information on registering for avalanche classes visit mtavalanche.org/education, or visit the GNFAC home page for up-to-date avalanche advisories and local conditions. The MSU Outdoor Recreation Program also offers avalanche rescue clinics to teach recreationists how to use an avalanche beacon and probe. The last class of the year is on Tuesday, March 8, from 3:30-5 p.m. at the Outdoor Recreation Center and is for all experience levels. For more information and to register visit montanastate.campuslabs.com.