the
SNOWY TORRENTS Avalanche Accidents in the United States
1996–2004
Knox Williams Spencer Logan
FOREWORD The Snowy Torrents has been the most important source of information on avalanche accidents in the United States for the last 50 years. Four volumes of The Snowy Torrents have been published, but it has been more than twenty years since the last edition. The American Avalanche Association, with assistance from the Colorado Avalanche Information Center, is proud to continue this tradition with the publication of this book. As an association, we are dedicated to promoting and supporting professionalism and excellence in avalanche safety, education, and research in the United States. This book exemplifies that dedication by examining more than 200 avalanche accidents that have occurred in the US during the eight-year period from 1996-2004. We have learned a lot about avalanches and avalanche safety since the first volume of The Snowy Torrents was published in 1967. During that time, the popularity of winter sports, the number of people traveling in avalanche-prone terrain, and the sophistication of avalanche rescue equipment have all grown. Much has changed, but avalanche accidents still occur. As professional and recreational users of avalanche terrain, we still have room to improve. The case studies in this book have been carefully studied and reviewed by the authors and offer a chance for all of us to learn from others. We learn from our experiences, both individually and collectively. John Dewey wrote, “Failure is instructive. The person who really thinks learns quite as much from his failures as from his successes.” I implore you to use this book as an opportunity to learn from others and add that knowledge to your own. When you read a report, strive to stand in the shoes of those involved. Could you have made similar mistakes? What human tendencies can you identify with in a given report? Be objective and ask yourself how you would approach a similar situation differently. The American Avalanche Association will continue to move forward with additional volumes of The Snowy Torrents. Individually, we must make better-informed choices, and as a community, we must continue to share these choices—regardless of the outcome—so that others may live to enjoy the snow. It is my sincere hope that future volumes will contain fewer fatal accidents and more stories about close calls with positive outcomes. This will require members of our community to report not just fatal accidents, but their close calls, as well. Tragedy averted is not solely the work of luck; it is the sum of our knowledge and experience while dealing with uncertainty. —John Stimberis President, American Avalanche Association
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1996–1997
SEASON
1996–1997 SEASON
19961111
TRUMAN GULCH, WEST OF BRIDGER BOWL SKI AREA, MONTANA | November 11, 1996 One backcountry skier caught, partially buried, and injured WEATHER AND SNOWPACK CONDITIONS
Winter began in the Bridger Range of southwestern Montana when about three feet of snow fell in two late October storms. Near-surface faceted snow grains formed on all aspects in the Bridger Range during a Halloween cold spell. On November 4, three inches of new snow fell in the Bridgers and buried the near-surface faceted grains. From November 7 through 9, winds were strong from the west, with average wind speeds around 30 mph and gusts near 60 mph. ACCIDENT SUMMARY
Traveling alone
Two backcountry tourers and their dog were skiing in Truman Gulch on the west side of the Bridger Range. The party had climbed up the slopes of Bridger Bowl Ski Area, and then crossed the ridge into Truman Gulch. The pair noted variable snow conditions due to the recent strong winds. Both skiers carried avalanche safety gear. Around 12:30, the partners were out of sight of each other, separated by a slight ridge. The lead skier began to descend a gully full of drifted snow. He made two or three turns when the avalanche broke above him. The avalanche quickly knocked the skier down. He lost his skis and poles shortly after being caught. He was in “total swimming mode” as the avalanche carried him about 700 vertical feet through trees and over small rock bands. He received numerous contusions, including a deep contusion to his thigh from hitting a tree. RESCUE SUMMARY
The first skier was near the toe of the debris when the avalanche stopped. He was partially buried with only his face exposed. His head was downhill and his arms were near the snow surface. He was able to free his arms and dig himself out of the debris. He moved to some nearby trees. The second skier was just over a small ridge and did not see the avalanche occur. When he got to the gully, he saw the avalanche crown with no exit tracks. He began a search for his partner within a “few” minutes of the avalanche. As the second skier neared the avalanche debris, he heard his partner yelling. The pair decided that self-evacuation was not possible due to injuries and lost gear. The injured skier got comfortable and waited. The second skier climbed back up to the ridge and skied to the base lodge at Bridger Bowl where he notified the Gallatin County Sheriff’s Office. Two members of the Bridger Bowl Ski Patrol and two members of the Gallatin County Search and Rescue responded to the incident. They lowered the injured skier about 300 feet to a point where a helicopter was able to land. The skier was flown to a hospital. AVALANCHE DATA
Persistent Slab avalanche
The slab was drifted snow about one foot deep and 10 to 20 feet wide. The slab failed on a layer of near-surface faceted crystals buried under the wind-deposited snow (SS-ASu-R2-O). The slope faced northwest with a slope angle of 36 degrees.
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1996–1997 SEASON COMMENTS
This accident included several elements common in early season conditions. Areas of wind-drifted snow, like the gully, offered sufficient snow depth to ride, but the slabs of drifted snow also sat over a thin layer of weak, faceted snow. Thus, in isolated spots, triggering avalanches can be possible or likely. A victim caught in a slide like this can be slammed into obstacles like rocks and stumps that are barely covered by the shallow snowpack.
PROVIDENCE LAKE, SOUTHEAST OF LOGAN PEAK, UTAH
19961206
December 6, 1996 Two snowmobilers caught; one fully buried ACCIDENT SUMMARY
Two snowmobilers, both in their late 20s, were riding powerful hillclimbing machines and highmarking on an east-facing slope near Providence Lake, in the Bear River Range of northern Utah. One rider got stuck on the slope, and the other rode up to help. The avalanche broke about 200 feet above them at about 17:15 in the afternoon, and caught both riders.
More than one person on a slope
RESCUE SUMMARY
One rider was partially buried and able to free himself from the avalanche debris. The other rider was fully buried. Another party of five snowmobilers saw the avalanche and rode to a nearby warming hut where there was a cache of avalanche rescue probes and shovels. They returned to the avalanche and began probing. Another party of three riders joined shortly after. Rescuers estimated that they had to search an area “50 by 60 feet.” The fully buried rider was located and the rescuers had uncovered his airway in about 15 minutes. He was buried facing downhill, with his head about 1.5 feet deep. He was unconscious but breathing when rescuers reached his head. The rider rested in the warming hut and rode back to the trailhead. One of the rescuers used a ham radio and reached 911 about the same time the rider’s face was uncovered. AVALANCHE DATA
Rescuers estimated the avalanche as about 300 feet wide. The slab was about 1.25 feet deep, with the majority of the slab on the hill the riders were climbing. COMMENTS
The group did not have rescue equipment. One of the rescuers noted that a key factor was having avalanche rescue equipment nearby at the warming hut. “They were put there a couple of years ago after another close call...[and] probably made the difference between life and death.” The nearby hut provided a location for the buried rider to recover, too.
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No rescue equipment
1996–1997 SEASON
19961207a
CURRANT CREEK PEAK, SOUTHEAST OF HEBER CITY, UTAH | December 7, 1996 Three snowmobilers caught and partially buried ACCIDENT SUMMARY
More than one person on a slope
Several snowmobilers were highmarking a very steep (45-degree) slope near Currant Creek Peak between the Wasatch and Uinta Mountains, about 10 miles southeast of Heber City, Utah. One rider got stuck high on the slope. Another rider got stuck just below him on the same slope. A third snowmobiler rode up to help. The avalanche released and caught all three. RESCUE SUMMARY
No rescue equipment
All three riders were partially buried-critical with just their hands sticking out. One rider freed his hand and eventually got himself out. He then helped dig one of the other riders out. They could not find the third rider. The two broke off tree branches and began to randomly probe the debris. A number of other snowmobilers in the area joined the search. One of the pair who self-rescued was probing about 100 feet above where he was buried. He saw the fingers of a glove sticking out of the snow. Rescuers dug down about three feet and found the rider blue in the face and not breathing. He started breathing on his own and eventually recovered enough to ride out. Rescuers estimate the third rider was buried about 25 minutes. He was wearing a helmet with a face shield, which was not filled with snow. AVALANCHE DATA
Persistent Slab avalanche
This avalanche broke four to five feet deep and 150 feet wide. The bed surface was a threeweek-old rain crust. The weak layer was faceted snow on top of the crust. The avalanche occurred on a steep, east-facing slope. It was a sunny Saturday, and the day after a storm. COMMENTS
Three very lucky riders. The next report describes a similar incident that occurred on the same day and also involved multiple riders caught with no companion rescue equipment. One of those riders was not so lucky. The incidents are two of five avalanches that caught 10 people on December 6 and 7, all documented by the Utah Avalanche Center. An avalanche warning was in effect from December 3 to 6.
19961207b
BOUNTIFUL PEAK, EAST OF FARMINGTON, UTAH December 7, 1996 Three snowmobilers caught; two partially buried, and one buried and killed ACCIDENT SUMMARY
A group of four snowmobilers, Rick Adams (37), Todd Lomax (29), J.D. Horne, and Chad Horne, were riding together. They were highmarking a steep, east-facing bowl
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1996–1997 SEASON along the ridgeline of Bountiful Peak in the Wasatch Range, east of Farmington, Utah. Each rode the slope one at a time while the others waited below. Adams was riding near the top of the slope when the avalanche released around 11:40. Lomax was below Adams. “There wasn’t a sound at all. I just looked up and saw a wall of snow coming at us. I just yelled ‘Run!’ I just took off.” Lomax sped downhill and outran the avalanche. He yelled a warning to the Hornes, who were on foot and working on their sleds. The Hornes ran downhill. The avalanche caught J.D. and buried him to his waist. Chad was hit by his snowmobile, which the avalanche had sent tumbling through the air. Chad was almost completely buried, with only one hand above the debris and his snowmachine almost on top of him. RESCUE SUMMARY
Lomax helped rescue the Hornes. None of the group carried avalanche rescue equipment. They saw no sign of Adams. They searched the debris surface and sent one person for help. About 20 search and rescue personnel, including dog teams, arrived at the site in the afternoon and searched until dark. On the morning of December 8, searchers conducted explosive mitigation and got “spectacular” results, triggering avalanches on both sides of the initial avalanche. Searchers probed the debris for two days before the suspending the search. Adams was recovered on December 19, 11 days after the avalanche. A group from the University of Utah’s Department of Geology brought in a magnetometer. A few days prior to their search, friends of Adams had found snowmobile tread marks on a tree in the upper track. The geologists began searching a swath downhill from the marked tree. They “hit a huge magnetic spike” in a group of trees about 100 feet above the toe of the debris. They dug down five feet to find Adams’s snowmobile. They began a fine probe search from the snowmobile working uphill. The probe line found Adams 30 feet uphill from the snowmachine, under four feet of snow, lying horizontally with his head pointing upslope.
No rescue equipment
AVALANCHE DATA
Investigators on the debris next to two of the party’s snowmobiles. Photo Bruce Tremper, Utah Avalanche Center.
The initial avalanche averaged two feet deep, 600 feet wide and started on a 40-degree, east-facing bowl which spanned the aspects from southeast through northeast (SS-AMu-R3-O). It descended about 500 vertical feet with the crown face around 9,100 feet in elevation. The debris covered an area of about four football fields and was up to 15 feet deep where it filled a gully. The avalanche ran on a stout rain crust formed about three weeks prior to the accident. The weak layer was two to three mm of faceted snow, formed from low-density new snow that fell on top of the rain crust. The slab consisted of snow from two storms in the week prior to the accident, both with relatively dense, rimed snow. The structure described above was capable of producing large avalanches, as exemplified by the “spectacular” results on the morning of
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Persistent Slab avalanche
1996–1997 SEASON December 8. Specifically, one 4kg hand charge triggered an avalanche on one flank three to six feet deep and over 1,000 feet wide. The other flank broke out two to three feet deep and 600 feet wide with several 2kg hand charges. COMMENTS High avalanche danger
19961223
The Utah Avalanche Center issued an avalanche warning on each of the four days prior to the accident. The center rated the avalanche danger High on slopes like the one that avalanched. These riders were among the 10 backcountry travelers caught in avalanches in northern Utah on December 6-7. This group was riding the slope one at a time. However, the rest of the party had not moved far enough from the slope and were still exposed to potential avalanches. When the avalanche released, it caught three of the four riders. None of the riders were equipped with avalanche rescue gear. With transceivers, probes, and shovels, it is possible they could have located Adams and excavated him in time. It certainly would not have required several days of search and rescue volunteers conducting a fruitless search in potentially dangerous conditions.
CHAIR PEAK, NORTHWEST OF SNOQUALMIE PASS, WASHINGTON | December 23, 1996 Two climbers caught, fully buried, and killed WEATHER AND SNOWPACK CONDITIONS
In the Snoqualmie Pass area of the Cascade Range, over two feet of snow fell between December 20 and 23. The new and drifted snow buried several layers of surface hoar and storm instabilities. Snowfall was light and scattered on Sunday, December 22. The weather deteriorated significantly Sunday night, with an additional seven inches of snow and 0.7 inches of snow-water equivalent falling with increasing southwesterly winds. Temperatures warmed during the day on Monday. An additional 1.3 inches of snow-water equivalent fell with strong southwesterly winds on Tuesday, December 24, with significantly rising temperatures and freezing levels. ACCIDENT SUMMARY
On Sunday, December 22, two climbers, Robert Mattson and Matthew Ichihashi, both 19, headed out to climb Chair Peak. Chair Peak is a popular climb about four miles northwest of Snoqualmie Pass. The pair snowshoed in on Sunday to establish a base camp. Rescuers assume the pair climbed Monday morning and triggered or were caught by the avalanche Monday morning or early afternoon. RESCUE SUMMARY
Family members reported the climbers overdue around 20:00 on Monday, December 23. King County Search and Rescue teams began searching early Tuesday morning. Deteriorating weather hampered the search. Rescuers experienced rising temperatures, increasing snowfall, and poor visibility. Avalanche conditions were dangerous, with
30
1996–1997 SEASON numerous natural avalanches occurring. Authorities suspended the search after “three avalanches struck in two hours.” Clearing skies on Wednesday, December 25 allowed a helicopter fly-over. Rescuers spotted the climbers’ tent on a bench above Source Lake and a faint hiking trail that disappeared into avalanche debris. They also saw evidence of an avalanche crown extending around much of the cirque to the east of Chair Peak. They concentrated their efforts in the avalanche debris and located the climbers late Wednesday afternoon by transceiver search. The transceivers were early Christmas presents. The climbers were found within 30 feet of each other, buried under 2.5 to 3.5 feet of avalanche debris. AVALANCHE DATA
The Northwest Avalanche Center issued avalanche warnings for High danger December 20, 21, and 22. Over two feet of snow had fallen on “several weak layers” of surface hoar and storm instabilities in the area since December 20. Numerous natural and triggered avalanches were reported from the nearby Alpental Ski Area, in avalanche paths above Interstate 90, and in the surrounding backcountry Sunday and again on Monday.
High avalanche danger
COMMENTS
The victims headed into the backcountry when the avalanche danger was rated High and an avalanche warning was in effect, though whether the victims knew of the warning is unknown. In these conditions, large natural avalanches and human-triggered avalanches are likely or very likely. It is difficult to avoid being in or below avalanche terrain, so backcountry travel is not recommended. Sadly, the victims’ newly-gifted beacons did them little good, because they were both buried. One hopes the beacons did not contribute to an over-confidence in their skills to manage the dangerous conditions.
FLAGSTAFF MOUNTAIN, NORTH OF ALTA, UTAH
19961226
December 26, 1996 One backcountry snowboarder caught, buried and killed ACCIDENT SUMMARY
Flagstaff Mountain is a popular backcountry area in the Wasatch Range above the town of Alta, Utah. Greg Dres (35) was last seen around 15:00 on December 26, heading up Flagstaff in stormy weather. He failed to meet his girlfriend that night. The morning of December 27, she and friends discovered that Dres’s car had been towed from the Flagstaff trailhead overnight. RESCUE SUMMARY
Search and rescue personnel began looking for Dres on December 27. Late in the day, Al Soucie, the US Forest Service Snow Ranger for Little Cottonwood Canyon, joined the crew of a Life Flight helicopter in an aerial search. They noticed a large avalanche in Days Fork, the drainage just northwest of Flagstaff Mountain. However, it was too windy to land and too late to launch a ground search.
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Traveling alone