Four snowmobilers were buried in an avalanche in the Sawtooth Mountains about 36 miles north of Ketchum Sunday afternoon, killing one and injuring one, according to the Blaine County Sheriff's Office.
Killed in the avalanche was George Gilbert Martin, a 64-year-old Bellevue man. He was buried in the snow for 60 minutes, and those at the scene were unable to revive him with CPR.
His wife, Lesley Dianne Martin, 70, also of Bellevue, was transported to the hospital for treatment of injuries and hypothermia. She was buried in the snow for 90 minutes.
"They speculate that she had a pocket of air," said Holly Carter, a spokeswoman for the sheriff's office. She is listed in good condition Monday afternoon at St. Lukes Wood River Medical Center, a hospital spokeswoman said.
The group was snowmobiling about 2.5 miles up Frenchman's Creek in the Smiley Creek area northwest of Galena Summit when the avalanche occurred just after 2 p.m.
The avalanche broke from the top of the ridge and ran down the hill, across the meadow hitting and buried all four, according to the Blaine County Sheriff's Office.
Susan A. Swanton, 56, and Robert C. Swanton, 65, of Sutherlin, Oregon were able to dig themselves out. Then they began searching for their companions. They found George Martin, but were unable to locate a beacon signal for Lesley Martin.
They rode one of the unburied snowmobiles down to the highway to flag down help. Three other snowmobilers summoned to the scene were able to find Lesley Martin's beacon, and they quickly dug her out.
Leslie Martin was transported to the hospital by the Ketchum Fire Department. She had symptoms of hypothermia and was admitted in stable condition.
All four snowmobilers were wearing avalanche beacons, the sheriff's office said.
"The use of avalanche beacons was a critical tool locating the victims involved in this avalanche," Blaine County Sheriff Gene D. Ramsey said in a release Monday. "We continue to stress that the backcountry is extremely unstable and we strongly encourage people to wear beacons and be properly equipped if they are not going to stay out of avalanche areas.
The Sawtooth Avalanche Center determined the meadow is a natural avalanche pass.
"It appears that the fracture initiated when one of the victims stepped through the new snow slab and penetrated the old faceted layer at the ground," the sheriff's office said. "This caused a large collapse that propagated uphill and released the avalanche 9000 feet in elevation in the uppermost part of the path."
The avalanche traveled about 1,400 vertical feet, according to the Avalanche Center. The "debris" was 4 to 8 feet deep and 300 to 400 feet wide, and it was categorized as a "D3 avalanche." That means the strength of the avalanche could bury and/or destroy trees, vehicle or wood-framed house.
From the Sawtooth Avalanche Center's website:
"Continued snowfall and wind-loading will maintain or elevate the danger in all middle and upper elevation terrain. Avalanches will likely fail on mid-storm weaknesses and could be large. Avoid wind-loaded slopes, steep consequential terrain, and large avalanche path runouts. At lower elevations, natural wet snow avalanches are possible before temperatures cool and you may encounter isolated wind slabs following today's forecast wind event."
View Fatal avalanche in Blaine County in a larger map