Human-Triggered Avalanche Underscores Hazard Conditions

By Beacon Staff

A large avalanche in Glacier National Park that swept a skier nearly 800 feet last week underscored the dangerous backcountry conditions in Northwest Montana.

A skier from Missoula suffered substantial injuries after being caught in a human-triggered avalanche a day after safely skiing the same section of Elk Mountain near Marias Pass. The skier was partially buried and sustained a broken arm, six broken ribs and head lacerations on the afternoon of Jan. 8, according to an incident report released by the Flathead Avalanche Center. A snowboarder accompanying the skier who witnessed the slide alerted 911.

The skier was not wearing an avalanche transceiver. He was buried above his waist and his helmet was broken into pieces, the report said.

The avalanche occurred on a south/southeast facing slope on the south side of an area locally known as “The Backstrap.” The average slope angle of the starting zone was roughly 35 degrees, according to the incident report. Avalanche dimensions were difficult to determine due to conditions, but the crown depth appeared to range between 12 to 36 inches deep. The avalanche was almost 145 feet wide and ran approximately 1,400 vertical feet down slope. The crown was located at approximately 7,200 feet in elevation and the toe of the debris was around 5,800 feet.

The local hazard conditions rose to “considerable” that day and remained that way through Jan. 14, according to an advisory from the FAC. The arrival of significant snowfall in the past week and high winds created weak surface conditions at mid and upper elevations in the Flathead Valley.

“Natural avalanche activity is possible so avoid playing beneath steep opens. Backcountry users will need to avoid steep open terrain especially where wind loaded until conditions settle again,” the advisory reads. “Even steep sheltered terrain is suspect with the recent rain crust and the underlying buried surface hoar interface. Seek out sheltered low angled terrain to perform pit investigations and progress cautiously from there.”

Avalanche conditions were expected to drop to “moderate” after Jan. 14 with moderating temperatures and trace amounts of snow, according to an FAC advisory on Jan. 12.

However dangerous conditions still exist in several sections of backcountry.

“Weak interfaces in the upper third of the snowpack will be maintained and/or enhanced with the cold temperature,” the FAC advisory read.

“Wind slabs and cross loaded terrain will remain sensitive and will mellow with a little more time, but time is the key,” the report added.

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