Dozens of avalanches reported in a week’s timeframe
A string of avalanches last week has left the snow pack in the backcountry riddled with giant cracks and debris, and although no human deaths occurred, one canine companion was lost.
Some of the biggest avalanches occurred on White Mountain, on Gothic Mountain, near Walrod Gulch in Cement Creek, and in the Terminator Chutes of Crested Butte Mountain.
The largest avalanche of the group occurred on Saturday, February 9 at approximately 2:30 p.m. on White Mountain, a 13,400-foot peak with multiple bowls about six miles northeast of Crested Butte.
Crested Butte resident and international mountain guide Jean Pavillard was on White Mountain that day with five friends who were learning the necessary skills for mountain guiding. “It was a demonstration of guiding in complex terrain features,” Pavillard says, and adds the intent was to experience and test snow pack below, at and above tree line on different aspects of the mountain. Upon reaching the summit of White Mountain, Pavillard says they decided to ski the safest, most obvious line down along a low angle ridge between the north and south bowls.
“As we skied we used a very conservative approach,” Pavillard says of skiing from point to point, and within a certain lateral width. He says they had chosen three islands of safety from which to maintain visual and verbal contact. At the time of the slide Pavillard says he and two other skiers were at the lowest island of safety, two were at the middle and one was up top.
Pavillard says one of the other skiers with him at the lowest island asked why there were so many limits on their skiing, and he explained how a skier-triggered slide could propagate above the ridge and take everybody out. “I had just finished describing that to her, and maybe 10 seconds after that the slide went,” he says.
Pavillard says the avalanche was triggered by a skier coming down from the middle island. There was heavy wind loading up top, which created a thick surface layer. Pavillard believes as the skier descended, he encountered softer snow and sank into the snow pack more. By skiing deeper into the snow, he says it may have caused a greater impact, enough to cause a critical failure in a hidden, weak layer. Pavillard says for the five others skiing with him, it was their first avalanche experience.
A crown broke only a few yards to the left of the skier, and the entire south bowl slid almost 1,500 feet across, Pavillard says. Only moments later the north bowl slid nearly 2,000 feet across. Both bowls slid 2,000 vertical feet at a depth of 5 to 10 feet according to Pavillard’s estimates. Debris could be found a mile down the valley.
While the fourth skier directly triggered the avalanche in the south bowl, the avalanche in the north bowl occurred hundreds of feet away from his position. This type of avalanche is called a sympathetic slide. Crested Butte Avalanche Center director Alan Bernholtz says, “It’s an avalanche started by another avalanche… the energy created (by an avalanche) is enormous. It’s something that can’t be duplicated by a skier or explosives. An avalanche can rock or shake the terrain much farther distances than a regular backcountry skier. So it’s kind of a domino theory – when one fails, the other fails.”
Pavillard says he was unable to feel vibrations from the slide from his position, but the two skiers above could feel the ground shake beneath them. All six could easily hear the avalanche. “It’s an easy sound to recognize or remember, but hard to define. It’s kind of a big roar. It sounds sometimes soft, and sometimes very powerful,” he says. Pavillard says he’s seen slides of this magnitude from far off while skiing in the Swiss Alps, but he has never been so close to such a large avalanche.
The White Mountain avalanche was clearly visible from the town of Crested Butte and the slopes of Crested Butte Mountain Resort (CBMR). It was also readily visibly by helicopter, and it just so happened that a camera crew working on the next Warren Miller skiing movie was flying around CBMR filming action on the slopes when the slide occurred. Pavillard says the helicopter immediately flew north toward White Mountain to check for survivors. “They were on top of the game in making sure everyone was okay,” he says.
Only moments before the White Mountain avalanche, a large triggered slide occurred at CBMR. CBMR ski patrol director Erik Forsythe says patrol set out mid-day on an exploratory mission into the Terminator Chutes to see if they were safe for an afternoon filming session. “Obviously they weren’t,” Forsythe says.
The Terminator Chutes are a series of three chutes to the skier’s left of Sunset Ridge, outside of the ski area boundary.
Patroller Billy Rankin says the slide occurred at 2 p.m., and was triggered by a four-pound ‘air blast’ explosive used for avalanche control work. Rankin says the slide was between two and five feet deep, occurred 50 feet above where the charge was placed, and ran 200 feet wide. “The debris took out several trees. It just went full track and spilled in this powder cloud over the cliff band,” Rankin says.
While both the White Mountain and Terminator Chutes avalanches were human triggered, a completely natural large avalanche occurred several days earlier on Tuesday, February 5 on the flanks of Gothic Mountain near the Rocky Mountain Biological Laboratory (RMBL).
Gothic’s only permanent resident and longtime RMBL business manager billy barr says over the course of 36 winters witnessing avalanches on Gothic, “That’s the biggest I have ever seen it run.”
barr estimates the slide was 2,000 feet across at the crown, and it ran over 3,000 vertical feet, not including the distance it went back up the other side of the valley. “It ran across the whole meadow all the way to the trees on the other side,” barr says.
barr says the avalanche was so powerful, the blast of air sent blocks of snow, branches and pinecones hundreds of feet back up the other side of the valley, and turned the snow on that side into hard pack. He says the same aspect of the mountain has created large avalanches before, and although this slide stretched over the RMBL research meadow, considerable slides have taken different directions and reached the Gothic townsite cabins before.
Bernholtz says the Gothic avalanche was unique because that day the Avalanche Center was reporting considerable danger in the backcountry, but not high or extreme danger – which is usually when large natural avalanches occur. Bernholtz says high winds early in the week may have put enough stress on an already overloaded snow pack, causing the Gothic slide.
The Avalanche Center was also reporting considerable avalanche danger on Friday, February 8 when a skier triggered slide occurred up Cement Creek, six miles south of Crested Butte. This avalanche claimed the life of a pet dog named Tara, but fortunately skiers Holly Annala and Erika Montgomery came out with only scrapes, bruises, and some missing equipment.
According to Annala’s report to the Avalanche Center, the day started with skiing a lap by the Cement Creek Caves, without any signs of instability. Then the two skiers and dog hiked up again and headed for a particular gully.
“People had directed us to this ‘low angle’ gully that they had just skied the day before, but we were not familiar with the terrain or the snow pack of this area,” Annala writes. Montgomery began first and skied toward a clump of trees and stopped. Annala then started making turns when the avalanche occurred.
She writes, “As I passed (Erika) on my turn, I heard her shout ‘come this way’ and knew immediately what it was. I swerved left because those trees were only 15 feet away, but there was no time before a blast of snow and air knocked me down. I slid and rolled probably 300 feet…I swam as much as I could but the snow was very heavy, I could only move one arm. But this was enough to keep my face and arm free when I came to a stop… We were both able to rescue ourselves, but the dog and some of our equipment was gone.”
While Annala was trapped, a second, sympathetic slide occurred several hundred feet away, but missed the two skiers. Annala writes, “Usually I am fairly cautious and don’t ski places I don’t know without a person who knows the area, and not on considerable danger days. The angle of the slope fooled us as well, because we couldn’t see the east facing rib that slid through the trees at the top. Often a look at the snow pack helps me make a decision but I passed this up as well. A series of bad judgment calls nearly cost me my life.”
Bernholtz says the Cement Creek slide would have been hard to predict, particularly because it was not an established avalanche path. “It’s very benign looking terrain. It looks like nothing could happen, but it just goes to show all you need is a slope steeper than 30 degrees, an unstable snow pack, and a trigger,” he says.
Numerous other slides were observed and reported in the same week. According to the Avalanche Center’s website natural avalanches have occurred on the flanks of Axtell Mountain, Whetstone Mountain and Round Mountain next to Highway 135, and near Pitkin. Another avalanche was reported to be caused by a snowmobile above Cement Creek Ranch, which also caused several smaller sympathetic slides.
As of Tuesday, February 12 the Avalanche Center was reporting a danger rating of considerable at and above tree line, and moderate below tree line. However, Bernholtz says conditions can change daily, and because of the type of snow the area receives along the Continental Divide avalanche danger can linger for weeks in certain areas. “We’re having a really good winter as far as stability goes, but people have to remember that each storm can bring instability in the snow pack…the snow pack, being mid-February, is going to be in a transition and people need to be aware,” Bernholtz says.
Weather and avalanche information for the Crested Butte area can be found at www.cbavalanchecenter.org