JACKSON HOLE, Wyo. — Recent heavy snows after a mild November has increased avalanche danger in a hurry. Several incidents around the region—some deadly—highlight the need for awareness when traversing in the backcountry.
Recent slides
According to the Bridger-Teton Avalanche Center, a few incidents since Christmas day have been worrisome.
On December 29 six snowmobilers remotely triggered a persistent slab avalanche at 8,590’ while riding a north facing slope near Stewart Peak in the Greys River area. All were wearing necessary avalanche gear and radios and deployed AVY bags upon first sign of instability as the slide made its way down the mountain.
“The avalanche came down fast from way above the riders and knocked two of riders off their sleds, but they stayed above the snow and were not buried,” stated one observer.
A day earlier, on December 28, skiers using sleds to access the chutes above Ski Lake stomped hard before they descended to test stability. Good thing they did. On the third stomp, the snow cracked just below one of the skiers, exposing the area behind it down to the rocks and ground.
“Stay away from Chicken Scratch (on Glory) and the like. These chutes are about the same elevation,” said one of the skiers.
On December 27, a trail groomer on Togwotee Pass noted a slide at about 9,226’ near the junction of V and K trails at the head of Maverick Creek.
A substantial avalanche upended trees on Treasure Mountain ridge in the Eddington Chutes area (south of Targhee) on December 27. The estimated 8-foot crown broke loose, running a full 1,400 feet to the valley below.
“I skin-skied briefly onto a low angle (sub 20 degrees) east-facing slope and heard an audible collapse. We immediately noticed a shooting crack running from my skis to the steeper slopes south. We remote triggered the avalanche from 500-800 feet away,” said one skier. “What we saw was astonishing. The crown was likely 10 feet at its deepest, and about 5-6 feet on the walls of the flanks. The avalanche clearly failed on the December 5th weak layer. The R4 avalanche ran the entire length of the path into the valley below, spraying a freight train of debris up the west side of Treasure Bowl summit.”
The pair of skiers thought about searching the debris for anyone who may have been caught up in the slide but considered the likelihood very slim. They had seen no tracks headed into the seldom-used area that day.
“The severe crown depth was clearly a product of monumental wind loading over the last week. We descended safely to the west, unharmed,” one of the skiers said.
Deadly avalanches
Two snowmachiners were buried and killed in an avalanche outside of Driggs on December 17. Kade McKinlay and Janson Webster, both 17 and both from Rigby, Idaho, were shuttling skiers to the top of Relay Ridge in the vicinity of Ryan Peak, west of Driggs at approximately 2:49pm on December 17 when a slide was triggered by one of the sledders.
More recently, two snowmobilers from Minnesota were caught and killed in an avalanche on Scotch Bonnet Mountain north of Cooke City, Montana on December 27. Reports pegged the enormous slide at 5 feet deep and approximately 300 feet wide on a southeast-facing slope.
Avalanche forecast
The current avalanche forecast calls for Considerable risk in the Greys River and Teton area; Moderate on Togwotee Pass.
“New snow over the past 24 hours combined with strong winds have created slabs that will be sensitive to human triggers above 8,000′. With additional snow and wind forecasted for this afternoon, expect these slabs to grow in size and sensitivity throughout the day,” the report stated today. “Avalanches involving the new snow have the potential to step down to older buried weak layers. Approach avalanche terrain conservatively today, as the consequences of being caught may be severe.”
