24 miles SW of Jackson WY, Bradley Mountain, Heliski Client Three helicopter skiers including the guide were caught in a large avalanche they triggered, 14-16 inches deep, 300 feet wide and ran 1000 vertical feet. The guide and one client were partially buried and one client was totally buried. It occurred on only a 30-32 degree northeast facing slope and it drained into a gully where the debris could pile up deeply. One of the victims, a woman, was buried 10 feet deep and it took the guides 25 minutes of hard work to dig her out despite locating her with a beacon very quickly. The avalanche broke on a Christmas surface hoar layer which was widespread throughout much of Wyoming and Idaho. Although no new snow had fallen in the previous 4 days, temperatures had warmed over the previous couple days settling the overlying snow into a slab. It was in the mid 30's at the time of the accident. ----------------------------------------------------------------- Heli-skier is killed in huge avalanche By Angus M. Thuermer Jr. Jackson Hole News jhnews@wyoming.com 1/17/96 A 29-year old Amherst, Mass. skier was killed in an avalanche on the northeast slopes of Bradley Mountain Sunday. Ginger Shaw died of suffocation after being buried under 40 inches of snow for approximately 25 minutes. She was found with the aid of avalanche transceivers, but revival efforts failed. A second skier, part of a party of 15 on the peak that day with High Mountain Helicopter Skiing, was partly buried in the midday slide. The 9,292-foot high mountain is approximately 22 miles southwest of Jackson. A fragile layer of surface hoar under more than a foot of new snow was the culprit said Gary Poulson of the Bridger-Teton National Forest. He reviewed the incident with the ski company to see if there were any holes in High Mountains safety procedures. We haven't come up with anything yet, Poulson said. The avalanche broke across approximately 60 yards on a 30 degree slope at an elevation of 8,000 feet. The crown was about 16 inches deep. The slide ran 2,500 feet from crown to toe and descended an estimated 800 vertical feet. Debris were piled in a gully up to 10 feet deep, Poulson said. When Shaw was uncovered, pilot Ken Johnson of Mountain Rotors flew to Jackson and picked up Rusty Palmer and Rolf Belden to administer advanced resuscitation efforts. Back at the slide path, Palmer was awed by the avalanche track. It was an impressive avalanche, Palmer said. It was very long, very tight - a very narrow canyon. They were swept all the way to the bottom. Shaw was half way down the slope when it released. The stress level on the scene was high, Palmer said. The ski guides were all business as they continued cardio-pulmonary resuscitation which they had begun after uncovering Shaw. I can't say enough about the heli guides and the job they were doing, Palmer said. They were amazingly efficient. It was an amazingly easy for Rolf and me. The two concentrated on giving the victim drugs, ensuring her airway was open, supplying oxygen and placing a heart monitor on her. Then they helped load her into the helicopter. Because the aircraft was not set up for transporting a patient, Palmer made the decision to land on the highway in the Snake River Canyon and bring Shaw to Jackson via ambulance. A vehicle from Alpine was waiting. It's my feeling that 40 minutes of good resuscitation is always better than 5 minutes of bad resuscitation, he said. Belden and Palmer continued lifesaving efforts. They were in contact with a doctor at St. Johns Hospital. On the way a mutual decision was reached to stop the revival efforts. The struggle to restart Shaws heart had been going on for an hour and 40 minutes, Palmer said. At some point you've got to realize you can't do anymore, Palmer said. There just wasn9t anything else we could do. It was very sad. Shaw was a long-time client of High Mountain. She had been skiing with the company since the mid 1980s. High Mountain guides and clients had been in the backcountry the previous three days skiing slopes at similar elevations and aspects. It was their first day on Bradley. Ironically, it was a day when forecasters at the Bridger-Teton's 733-2664 avalanche hotline had downgraded danger from high to moderate. There was a caveat; A weak layer persisted one to three feet below the surface and human triggered avalanches would be possible on colder aspects, forecasters warned. Guides on the day's outing had 50 years of collective experience in heli-skiing and mountain guiding. To test the fatal slope, at least one had skied across the avalanche starting zone, but the snow had held fast. The crew is authorized to use explosives to test slopes but none were employed Sunday. The death is the first in the company's 20-year history. A co-owner of the company had been buried previously and others have been swept downhill by slides but not covered. The weak layer of surface hoar formed from water vapor forming crystals on the top of the snowpack during a cold spell when there was no snow, Poulson explained. On top of the fragile crystals, almost a foot and a half of new snow subsequently fell. That loose snow coalesced into a soft slab because of warming temperatures, Poulson said. When disturbed by the critical weight, the slab cracked and began to slide on the weak layer, starting the avalanche. Junie Fuchs, owner of the company said the crew did a good job locating Shaw and the other victim. We thought it to be quickly when you consider all the circumstances involved, he said. We're very, very confident we did everything possible to recover and evacuate the victim as fast and safely as possible. ----------------------------------------------------------------- A deadly layer of frost Rockies. By Angus M. Thuermer Jr. Jackson Hole News jhnews@wyoming.com A long period of cold, clear weather followed by snow may be responsible for creating a weak layer in the snowpack across the Rockies that has killed five people. An avalanche that ran on the weak layer of 3surface hoar2 killed 38-year-old Amherst, Mass., resident Virginia 3Ginger2 Shaw when she was helicopter skiing south of Jackson Jan. 14. Similar avalanches killed a snowboarder near Vail, two others near Sun Valley, a cross-country skier near Laramie and buried three snowmobilers in Montana. Bridger-Teton National Forest avalanche hazard forecaster Jim Kanzler believes the same weakness may be responsible for all the incidents. This hoar is tricky stuff, Kanzler said. It makes a good sliding surface. Kanzler, whose daily hazard report can be heard by dialing 733-2664, said hoar is like a winter dew. It is formed from moisture in the air crystallizing on the snow's surface during periods of cold, still weather. Conditions ideal for forming surface hoar dominated the Rockies at the end of December. Surface hoar water crystals can be small or can grow to several inches in height. The Avalanche Handbook by David McClung and Peter Schaerer says other complex factors also help the crystals grow. Water vapor moving through the snowpack from the warm ground to the cold surface may add to the growing crystals, the authors write. The result is a miniature forest of delicate ice plates balanced on top of a snow slope. There, they are of little consequence. Buried by new snowfall, however, they become a big danger. Following the cold, snowless weather that prevailed in the Rockies in December came a series of storms. They provided the snow slabs that have slid on the now-buried surface hoar. Backcountry skier Keith Benefiel likened buried surface hoar to Teflon-coated playing cards. They are both slick and flat, and may even support an overlying layer of snow like a house of cards. All that is needed is a trigger, like a skier crossing a slope, to break free a slab of snow and start an avalanche in motion. The danger sometimes eases with time, Kanzler said. But the threat can remain in isolated pockets for weeks. Kanzler said it's possible for such slides to run as long as two months after the formation of surface hoar. It's documented, he said. We could have problems next month.