Saturday’s avalanche that claimed the lives of four Utah backcountry skiers could have been even deadlier but for the fast rescue work by one skier who clung to a tree to escape the slide that carried away seven others.
Two separate parties of skiers were ascending a bowl in Mill Creek Canyon outside Salt Lake City when a 1,000-foot-wide avalanche broke loose above them, scouring much of Wilson Glade’s northeast face, according to the Utah Avalanche Center, which is investigating the accident and will post a full report in the coming days.
The debris completely buried six skiers and partially buried a seventh. The one skier who was not trapped initiated a search for his buried companions. Using a transceiver, this skier, who has not been officially identified, quickly found signals being transmitted by beacons carried by the buried skiers and dug down to two trapped under 3 to 5 feet of snow, according to forecaster Drew Hardesty.
“He ... grabbed a tree and held on for dear life while all the while the avalanche washed over him and buried everyone else,” Hardesty said. “And at that time, to see this occur and then have the wherewithal to go acquire the [beacon] signals and do not one but two full and deep burials and rescue two lives, is amazing.”
While those two were rescued in time to save them from possible suffocation, by the time the others were found, they were already dead from suffocation or traumatic injuries they may have sustained, according to preliminary report posted by the avalanche center. The U.S. Forest Service operates the center as a public service to help keep backcountry recreationists safe.
Wilson Glade is in Mill Creek Canyon’s upper reaches under the divide with Big Cottonwood Canyon in the heart of the Wasatch Mountains’ ski country, famed for its fine snow in easy-access alpine terrain.
According to official reports, one group of five skiers entered Wilson Glade from Big Cottonwood while a group of three entered from below in Mill Creek. Both groups were ascending when the avalanche released, according to forecaster Nikki Champion. It was not known whether the avalanche released naturally or if the skiers triggered it “remotely,” that is, from a distance.
The skier who managed to avoid getting trapped by the slide was touring in the group of five.
In most backcountry avalanches, a skier or snowmobiler triggers the slide while riding or skiing in the starting zone. That does not appear to be the case in what is Utah’s deadliest avalanche since 1992.
Utah’s lethal avalanches typically occur on slopes that face north or northeast, are pitched steeper than 38 degrees, and exceed 8,000 feet in elevation, according to a 2015 analysis by Hardesty.
Saturday’s slide fit those characteristics with the exception of slope angle. This avalanche was triggered on a relatively tame 31-degree slope, likely evidence that the conditions were exceptionally unstable that day.
Due to Utah’s shallow snowpacks, the recent round of midwinter storms led to extreme avalanche hazards as the new dense snow piles on what forecasters call “persistent weak layers” that are primed to release.
The Wilson Glade slide was also substantially larger than initially reported. A 3.5-foot-deep “hard slab” broke free across 1,000 feet and tumbled 400 vertical feet, according to an updated preliminary report.
While skiing avalanche-prone slopes, backcountry skiers are taught to keep enough distance from one another to minimize the chances that more than one will be caught in the event the snowy slope gives way. That way if someone is completely buried, their companions may be in a position to rescue them.
This principle generally works while parties are skiing down a slope. It’s rare for more than one skier to get caught in most Utah slides, but Saturday’s massive avalanche occurred while these groups were ascending, presumably in single file via a “skin track,” according to Hardesty. As a result, all eight skiers were in the slide’s path at once even though the two groups were fairly far apart. Two skiers in each group survived.
“Multiple-casualty avalanches are uncommon in the course of looking at our avalanche accidents since 1940. They do happen, but they’re rare,” Hardesty said. “I would say that by many metrics and standards, this avalanche accident bucked the trend, because our average number of accidents over the last 30 years has either flat-lined or slightly diminished — despite the exploding use of the backcountry.”
Avalanches have claimed 21 lives across the U.S. this season, 15 in the past week alone, putting this winter on track to being among the deadliest on record. And winter is barely half over.