Avalanche
A group of three snowbike riders were all caught in a fatal avalanche in the South Fork of Dickson Creek, east of Red and White Mountain near Valley Vail, CO on Feb. 15, 2020. All three of them were caught, one was partially buried, and two were killed.
The CAIC said in a report that the group unintentionally triggered a hard-slab, medium-sized slide relative to the avalanche path that produced enough force to injure, bury, or a kill a person. It happened when a persistent weak layer failed. It is believed that the avalanche broke on an old layer of faceted snow roughly three feet below the surface and was likely triggered from the bottom of the slope. The crown was 3 to 4 feet deep, 600 feet wide, and the debris ran about 300 vertical feet, the CAIC said.
The group was prepared for backcountry travel as they were all carrying avalanche transceivers, probes, and shovels, Vail Daily reports. Riders 2 and 3 had avalanche airbag packs, although the triggers were zipped up in their shoulder straps at the time of the accident. It was when the group encountered a piece of terrain that they had not planned for did things take a turn for the worst. Here are the play by play events that led up to and followed the avalanche on this horrific day, provided by the CAIC.
Events Leading to the Avalanche
A group of three snowbike riders (Riders 1 through 3) left the Red Sandstone Road winter access point at about 10:30 AM on Saturday February 15, 2020. Their plan was to ride in the Red and White Mountain area. They rode up the groomed road (US Forest Service road 700) making their way to Red and White Mountain, playing on low-angle slopes and in meadows as they went. At one point they saw a group of snowmobilers high marking near a recent avalanche. They did not know when the avalanche released, but decided to continue avoiding steeper slopes.
At a hairpin turn in the groomed road (USFS Road 700 which goes over Muddy Pass), they spent some time playing in the meadows and open areas between the groomed tracks. Around 2:30 PM they crossed the groomed road and headed south up a narrow unnamed drainage with forested sides, near the headwaters of South Fork of Dickerson Creek. Rider 3 was in the lead, but started to bog down and made a sharp turn in a small open area to keep his momentum. Riders 1 and 2 continued up the drainage and Rider 3 looped around and followed their track (placing him at the back of the group). Riders 1 and 2 followed the creek bottom until it widened slightly and they reached an opening in the trees. There were dense trees ahead and on the slope to their left, but the northeast-facing slope to their right was broad, open, and steep with only sparse trees. Riders 1 and 2 made small looping turns in the bottom of the drainage and along the lower portion of the slope, so their bikes were facing down the drainage, back the way they had come.
Accident Summary
Rider 3 came into the open area and saw Riders 1 and 2 above him on the slope. He looked up and saw the avalanche breaking in the far upper left (southern) portion of the slope. He waved to Rider 1 as he turned uphill to head back down the drainage, passing between Rider 1 and Rider 2. All three riders were heading down the drainage, with Rider 3 furthest back the way they had come (to the north), when the avalanche overtook them. Rider 3 rode out the side of the avalanche into a group of dense trees. Only the track of his snowbike was buried in avalanche debris (partially buried-not critical).
Rescue Summary
Rider 3 got off of his bike and turned his avalanche transceiver to receive. The distance reading on the unit was 30 meters (98 feet) and the numbers decreased as he walked back up the drainage yelling for Riders 1 and 2. He reached an area where the distance reading dropped to 5 meters (16 feet), but could not find an area with a lower reading. He began to probe for his friends, but did not get a strike. He moved “3 or 4 feet” of snow off of the area and probed again. He got a strike and began to dig. After about an hour of digging Rider 3 had a narrow hole “about 10 feet deep”. He found Rider 1, but just a portion of his coat. Rider 3 knew he was going to need help. He got back on his snowbike and rode towards a yurt operated by Vail Backcountry Tours (VBT) that he passed that morning.
When Rider 3 reached the yurt, staff from VBT alerted Vail Mountain Rescue (VMR) and eventually the 911 dispatch center for Eagle County. Two people from VBT and Rider 3 returned to the accident site to continue searching. On their way back they encountered a group of six people on four snowmobiles and one snowbike. The six riders joined the rescuers and the group of nine all returned to the site and began digging out Rider 1 and looking for Rider 2.
The group had some difficulty locating Rider 2. The lowest reading they could get on an avalanche transceiver was 5.5 meters (18 feet). Eventually they got a positive probe strike under a tree about 20 feet (6 meters) across and slightly down the drainage from Rider 1. They worked to free Rider 2 until about 9:00 PM when Vail Mountain Rescue reached the site. Given the time elapsed, darkness, increasing snowfall, and no easy way to evaluate the avalanche hazard above the site, the group left and returned to the Red Sandstone trailhead. VMR returned the following morning to recover the bodies of Riders 1 and 2.
Comments
All of the fatal avalanche accidents we investigate are tragic events. We do our best to describe each one to help the people involved and the community as a whole better understand them. We offer these comments in the hope that it will help people avoid future avalanche accidents.
This group was prepared, but not planning, to travel in avalanche terrain. All three carried avalanche transceivers, probe poles, and shovels. Riders 2 and 3 had avalanche airbag packs, although the triggers were zipped up in their shoulder straps at the time of the accident. The group spent the entire day playing in dense trees or on low-angle slopes, specifically avoiding avalanche slopes. At the end of the day they decided to enter an unfamiliar drainage, and attempted to turn around and retreat when they saw the steeper slope. Maybe the only thing they could have done to avoid this situation is to use maps or a mobile phone app to look at the area before they left the road. Both the open nature of the slope and the slope angle over 30 degrees are apparent in satellite imagery and contour maps.
The avalanche forecast for the day described “tricky” conditions. The snowpack on this slope had one distinct and one subtle weak layer. Both were buried under a thick layer of snow about a week old. They were unreactive in Extended Column Tests and required fairly long cuts to get cracks to extend in Propagation Saw Tests. We don’t know what the snowpack looked like where the group triggered the avalanche or on the slope; all of that information was destroyed in the slide. However, data from snow profiles observed in the crown and flank of the avalanche are quite reflective of a spooky Moderate avalanche hazard: strong snow, avalanches are difficult to trigger, and avalanches large to very large maybe even bigger. A Moderate avalanche danger (2 of 5) can still describe dangerous avalanche conditions. In the last seven years, 32 people were killed in avalanches in Colorado. Eleven have died during periods of Moderate avalanche danger, including all four killed during the 2019-2020 season.
The slide caught the group in a terrain trap, a gully that produced a deep burial. Both riders were buried between 8 and 10 feet (2.5 to 3 meters) deep. This contributed to a difficult rescue scenario. We did not interview every member of the rescue party, but the discussions we had indicate the probes they used were less than 250 centimeters long. The group had to move snow off of both riders to pinpoint their locations.
