Avalanche kills snowmobiler near West Yellowstone

Multiple skiers buried in slides throughout southwest Montana

By Tyler Allen EBS Managing Editor

BIG SKY – A 40-year-old snowmobiler was buried and killed by an avalanche Jan. 2, approximately 19 miles north of West Yellowstone in the southern Madison Range. The incident occurred in the Cabin Creek drainage on the west side of Sage Peak.

Weylon Wiedemann, of Pine City, Minnesota, triggered the slide from the bottom of the slope and was pronounced dead at the scene.

Gallatin National Forest Avalanche Center forecasters Doug Chabot and Alex Marienthal completed the accident investigation on Jan. 3 and planned to release the report Jan. 4, the day after EBS went to press.

Reached by phone Jan. 3, Chabot said four snowmobilers and two snow bikers from Minnesota had triggered a small avalanche and decided not to ride in dangerous terrain. The group was experienced in snow safety, Chabot said, noting that they were all carrying avalanche rescue gear and two of them had ridden in the West Yellowstone area in the past.

One of the group members was approximately 50 feet away from Wiedemann, where he had stopped his sled, and watched him get carried about 25 feet down the slope into a small gully. The avalanche was a hard wind slab that failed on facets—or weak snow—near the ground. It was approximately 300 feet wide and ran about 600 feet on a southwest-facing slope, according to Chabot.

The avalanche pinned the victim, Weylon Wiedemann of Minnesota, beneath his sled and under 3 feet of snow.

Research into avalanche burials indicates that, barring trauma, a victim has an approximately 80 percent chance of survival if they’re dug out within 10 minutes. However, the weight of the snowmobile on top of Wiedemann may have played a role in his death, Chabot said.

“A lot of times you go investigate and say, ‘What were they thinking?’ This was not one of those incidents,” Chabot said. “There were no other signs [of avalanches] along Sage Peak, or [nearby] Skyline Ridge. They just got really unlucky, and they got a lot of things rights. That’s what makes it extra tragic.”

This was the fourth avalanche fatality this winter in the U.S. and the second in Montana. On Oct. 7, a slide on Imp Peak, south of Big Sky, claimed the life of 23-year-old Bozeman woman Inge Perkins.

Two skiers were also partially buried Jan. 2 by an avalanche outside of the south boundary of Bridger Bowl ski area. They were stopped underneath the cliffs near the lower flanks of Saddle Peak when a small wind pocket of snow was triggered above them. The skiers were not injured.

On Dec. 29, two skiers triggered an avalanche west of Cooke City, near Barronette Peak, that caught them both, partially burying one skier. They were flushed through trees but were not seriously injured. The day before, on Dec. 28, two skiers remotely triggered a slide in the Sheep Creek drainage northwest of Cooke City, partially burying one up to their neck.

An avalanche on the west side of the Bridger Range on Dec. 29 carried a skier 1,200 vertical feet, which partially buried him and resulted in wrist and knee injuries. The skier was evacuated by Gallatin County Search and Rescue with assistance from Bridger Bowl ski patrol.

Heavy snow and strong winds between Christmas and New Year’s Day spiked the avalanche danger to “high” on wind-loaded slopes in Cooke City on Dec. 28—the area received 4 feet of snow over four days—and “considerable” throughout the rest of the GNFAC advisory area. With a break in snowfall after New Year’s Day, the snowpack in southwest Montana was trending more stable, but was a “spicy moderate” on Jan. 3, according to the avalanche center.

Visit mtavalanche.com for more information on the Jan. 2 accident, or to sign up for the daily advisory email.

Editor’s note: EBS Managing Editor Tyler Allen also serves on the board of the Friends of the Gallatin National Forest Avalanche Center.