An overhanging edge of snow, or cornice, that broke underneath the feet of a Bigfork man in the Jewel Basin is what caused the deadly avalanche in early February, according to investigators.
Bigfork resident Mark Albee, 42, was backcountry skiing with his brother when he was killed by a large avalanche south of Wildcat Lake on Feb. 1.
Stan Bones, an avalanche specialist with Flathead National Forest, released the incident report for the Twin-Wildcat Lakes avalanche on Feb. 17, detailing the chain reaction event that occurred in old snow. Authorities had issued a regular backcountry avalanche advisory the day before the incident that rated the avalanche danger as considerable between the elevations of 5,500 and 7,500 feet on all mountain ranges. Backcountry travelers were advised that natural avalanches were possible, while human triggered avalanches were likely, the report said.
Albee was an experienced skier and was wearing an avalanche beacon at the time of the accident. He and his brother Iain had stopped on a ridgeline south of Wildcat Lake at around noon, the report said. Iain told investigators he and his brother were about to continue into the bottom of the Noisy Basin drainage “when he heard a pop, saw the snow crack and felt the snow settle under his skis, rocking him back on his heels.”
Bones wrote that the broken cornice appears to have triggered a slab release that was roughly 140 feet wide at the top of the ridge. The avalanche engulfed Albee and carried him roughly 500 vertical feet down the slope where his body was later found. Official cause of death was asphyxiation.
Failing slab thickness and crown heights were highly variable, ranging from 12 inches to over 10 feet, the report said.
The weight of the collapsing cornice was estimated to be close to 35 tons with a destructive force that could bury and destroy a car, Bones wrote. Huge cornices regularly grow at many ridge locations along the Swan Crest, the report said. The avalanche also began releasing across the slope further to the north, crossing over other rock outcrops and reaching into adjoining swales. This exponentially increased the amount of involved snow, the report said.
“We hold Iain Albee, both Mark and Iain’s families, and their friends in our prayers during this difficult time of loss,” Bones wrote in the final lines of the report.