Northern Gallatin

Two skiers were ascending a northeast-facing avalanche path on the northernmost ridgeline of Mount Blackmore around 1 PM when they triggered a large, dry slab avalanche that failed 3 feet deep, 150 feet wide, and ran 500 feet vertical. Debris piled up 4-8 feet deep. This photo captures the first area to avalanche on the climber's right side of the path. Photo: GNFAC

Northern Gallatin, 2024-03-19

Two skiers were ascending a northeast-facing avalanche path on the northernmost ridgeline of Mount Blackmore around 1 PM when they triggered a large, dry slab avalanche that failed 3 feet deep, 150 feet wide, and ran 500 feet vertical. Debris piled up 4-8 feet deep. One skier was carried to the bottom left of the runout zone. Photo: GNFAC

Northern Gallatin, 2024-03-19

Two skiers were ascending a northeast-facing avalanche path on the northernmost ridgeline of Mount Blackmore around 1 PM when they triggered a large, dry slab avalanche that failed 3 feet deep, 150 feet wide, and ran 500 feet vertical. Debris piled up 4-8 feet deep. One skier was carried to the bottom left of the runout zone. Photo: GNFAC

Northern Gallatin, 2024-03-19

Two skiers were ascending a northeast-facing avalanche path on the northernmost ridgeline of Mount Blackmore around 1 PM when they triggered a large, dry slab avalanche that failed 3 feet deep, 150 feet wide, and ran 500 feet vertical. Debris piled up 4-8 feet deep. Photo: GNFAC

Northern Gallatin, 2024-03-19

Deep Slab Avalanche near Mt Blackmore

Date
Activity
Skiing

Two skiers were ascending a northeast-facing avalanche path on the northernmost ridgeline of Mount Blackmore around 1 PM when they triggered a large, dry slab avalanche that failed 3 feet deep, 150 feet wide, and ran 500 feet vertical. Debris piled up 4-8 feet deep. The avalanche failed on weak, faceted snow near the base of the snowpack. 

As the group was about halfway up the avalanche path, they saw a small slide initiate to their right and then they heard a loud boom as the rest of the slope collapsed 250 feet above them. The skier lower on the path sprinted to the left into the trees to avoid getting caught. The second skier was 30 higher on the slope. He attempted to run off the slope but was unable to avoid getting captured. He was carried to the bottom of the avalanche path, got submerged in the snow, but thankfully came to rest on the surface. His partner initiated a beacon search and called his name, quickly finding him on top of the avalanche debris. The skier sustained significant injuries. They called 911 and Gallatin Country Sheriff Search and Rescue initiated a response with the Helicopter team. The two skiers worked to address injuries while awaiting rescue. GCSAR inserted a team with a helicopter that provided medical treatment and transported both the injured and uninjured skiers. The GNFAC was on scene to evaluate the scene for hazards to the rescue team. 

Region
Northern Gallatin
Location (from list)
Mt Blackmore
Observer Name
Dave Zinn

My partner and I were approaching Responsible FamilyMan via Avalanche Gulch early yesterday morning (3/18), and once we broke through the trees into the runout zone, we stumbled across a pretty large wet avalanche debris field. The debris terminated within ~50 yards of the max runout zone. Photo: R. Parsons

Northern Gallatin, 2024-03-19

Wet slide in Avalanche Gulch

Date
Activity
Ice Climbing
My partner and I were approaching Responsible FamilyMan via Avalanche Gulch early yesterday morning (3/18), and once we broke through the trees into the runout zone, we stumbled across a pretty large wet avalanche debris field. The debris terminated within ~50 yards of the max runout zone. It appeared to be a point release from a couple of pitches up (as we found no crown), and it just entrained a whole lot of snow on the way down. I've included some pictures.
 
We finished our day around 1:00pm when the gulch started receiving sun and hastily made our way back to the valley. 30 minutes of direct sun was all it took for us to notice rollerballs and a lot of meltwater seeping down the rocks.
Region
Northern Gallatin
Location (from list)
Hyalite - main fork
Observer Name
Robbie Parsons

Poor snow structure on Saddle Peak

Date
Activity
Skiing

On the drive up we could see a wet slide from yesterday that occurred in Argentina bowl, human triggered. We also got a report of a wet slide in St Lawrence path in Truman Gulch (not big). We toured along the ridge to the summit of Saddle. By 1000 the snow was softening. We dug below the first cliff band and found 7' of snow, the bottom 2' consisting of weak facets. A Deep Tap Test showed a clean shear at this interface. An avalanche could be triggered by 3 ways: more load from snowfall or wet avalanche debris, melt-water percolating through the snowpack to the facets, or human triggering from a thin spot.

By 1100 the snow was getting wet and punchy at lower elevations. Loose wet slides could trigger dry slab avalanches, a proposition we did not want to hang around for.

 

Region
Bridger Range
Location (from list)
Saddle Peak
Observer Name
Doug Chabot