Miscommunication among a large group of backcountry skiers was a factor that led to an avalanche that killed three Eagle County residents last week near Silverton, according to a final report from the Colorado Avalanche Information Center.

The avalanche, which occurred Feb. 1 near Ophir Pass in an area known as “The Nose,” caught four members of the seven-person group. Three died: Seth Bossung, 52, Andy Jessen, 40, and Adam Palmer, 49.

As with any avalanche involving fatalities, the CAIC performs an investigation into the circumstances that led up to slide. The final report for the incident outside Silverton was released Sunday.

The CAIC reported the group met Feb. 1 in Silverton for a multi-day backcountry hut trip east of Ophir Pass. The report says the age of the group ranged from people in their 30s to their 50s.

The report does not, however, identify any of the names of those involved.

“Some had been backcountry skiing together for many years, while others were new additions to the group,” the CAIC said. “Several of them had made annual trips into this hut for at least ten years. Four members of the group had been in the area since Friday skiing in the backcountry and with a local helicopter skiing operation. Three members of the group arrived Sunday (Jan. 31) evening.”

The group left Silverton around 10:30 a.m. Feb. 1 and drove to the winter road closure at Ophir Pass Road, a little more than 5 miles northwest of Silverton off U.S. Highway 550, before Red Mountain Pass.

At the trailhead, the group prepared for the outing, checking emergency transreceivers and discussing the avalanche conditions. At the time, the San Juan Mountains were listed at “considerable risk” for avalanche danger.

“Below treeline slopes may not propagate as wide, but avalanches will be deep and can be dangerous if they push you into trees or a terrain trap,” the CAIC’s avalanche report from that day read.

From Jan. 22 to Jan. 31, the CAIC documented more than 110 natural- and human-caused avalanches in the region – and that’s just slides reported to the center.

The group left the trailhead around 11:30 a.m. to head toward the hut. Noticing the avalanche danger on south-facing slopes, the group traveled one at a time through hazardous areas to reduce exposure.

The group arrived at the hut around 1 p.m., and decided to go out for an afternoon tour. The CAIC report says the group talked about The Nose, but did not plan to ski the area.

The manager of the hut, the CAIC reported, told the group there was “lots of avalanche activity on all aspects, and today is the warmest day since December.”

The group left the hut and went into a drainage between Ophir Pass Road and The Nose, and then climbed a gentle ridge to the south, heading toward The Nose.

Members reached a small saddle at 11,800 feet and decided to ski down a northeast-facing slope. The skiers went down one at a time, and started to regroup on a small knob above a gully.

And it was there where the tragic mistake occurred, according to the CAIC.

Before the entire group collected on the knob, one of the skiers, identified as “Skier 1,” began skiing down into the gully toward the Middle Fork of Mineral Creek. Two more people, Skier 2 and Skier 3, followed.

A fourth person, identified as Skier 4, also entered the gully. As Skier 4 was trying to warn Skier 3 to avoid steep slopes, the avalanche was triggered at about 3:20 p.m.

Skier 4 was the sole survivor of the avalanche. Speaking to the CAIC, Skier 4 said the avalanche happened in two waves.

Skier 4 was able to stay on his feet during the first wave and deployed an airbag. But then the larger, second wave hit and completely engulfed the group.

“It felt like I was in a river and I was fully under the snow for approximately 15 to 25 seconds,” Skier 4 said, and was “moving very fast a significant way down the gully.”

When Skier 4 came to a stop, his head was under the snow, but the airbag was visible on the surface. Skiers 1, 2 and 3 were completely buried.

The rest of the members of the group rode down into the gully and tried to find the buried skiers through a beacon signal. They spotted Skier 4’s airbag and quickly dug him out.

The group continued down the gully and found two signals close to each other, and a third signal about 100 yards farther down. The beacons showed the skiers could have been buried in up to 16 feet of debris and snow.

The group dug for more than two hours, and reportedly reached within 5 to 7 feet of the buried skiers. The group was even able to reach one of the buried skiers with a probe pole.

The CAIC said the group sent an SOS signal from an InReach emergency device at 4:40 p.m., and search and rescue crews in Silverton were mobilized around 5 p.m.

“At nightfall the four survivors were exhausted and made the difficult decision to start back to the hut,” the CAIC said.

Skier 4 had injured his knee in the slide, and lost both skies and poles. The group made snowshoes out of tree branches for him to be able to trek to the hut.

The group came into contact with search and rescue crews around 7:30 p.m., which helped the group back to the trailhead, arriving there around 10 p.m. The search was suspended until the following morning.

Because of avalanche danger and hazardous weather conditions, it took rescue crews a few days to dig out the skiers. The report says the skiers were found buried 9 feet, 11 feet and 20 feet under the snow.

The deceased skiers were flown out of the area by helicopter on Thursday.

Commenting on the incident, the CAIC said moving in large groups through avalanche terrain, one at a time, requires considerable time and careful coordination.

“Small communication errors and misunderstandings can be amplified in large groups,” the CAIC said. “This challenge may have played a role in this accident.”

The CAIC said there was an expectation among the group to regroup on that knob, but Skier 1 went down before everyone reconvened, causing the three other skiers to follow.

“There were suddenly four riders in the gully, all out of sight of the people on the knob when the avalanche released,” the CAIC said.

The CAIC said it was fortunate Skier 4 was higher on the slope, and able to deploy his airbag.

“The others were not as lucky, and were deeply buried,” the CAIC said. “In a terrain trap like this gully, the depth of avalanche debris can vary dramatically over a very small distance.”

The CAIC said deep burials are the most difficult, time-consuming parts of a rescue, dealing with fatigue, equipment breaking and large amounts of hard snow and debris.

“The four riders worked for hours and only got through the top half of avalanche debris above the victims,” the CAIC said. “Anyone who has dealt with avalanche debris over a few feet deep will tell you the digging gets more difficult and more complicated the deeper you go.”

Eventually, the CAIC wrote, it took an organized search and rescue group, with many people and power tools, two days to recover all three skiers.

The CAIC also pointed out that one of the skiers had a 10-year-old beacon. Newer beacons, the center said, can sometimes mistake one signal from an old beacon as two signals, which can cause confusion in finding buried skiers. Ultimately, the outdated equipment did not have a role in the outcome of the incident.

“It is a good reminder to make sure you understand the performance of the equipment you and your partners are using,” the CAIC said.

All three skiers who perished were well connected to the Eagle County community.

A joint letter from Eagle County and the town of Eagle said, “The families are surrounded by loved ones, and we are asking everyone to respect their wishes as to when and how they wish to communicate with others.”

Palmer was the county’s sustainable community director, and Bossung worked in the department. Jessen was the owner of the local Bonfire Brewery. Both Jessen and Palmer served on the Eagle Town Council.

“Our hearts are heavy with the loss of these three men,” the joint letter said. “Their contributions through their work in local government and local businesses, as well as their personal passions and their impact on the friends and family members they leave behind, have helped shape the community in ways that will be forever lasting.”

So far this winter season, the CAIC reports 10 backcountry users, including skiers, snowboarders and snowmobilers, have been buried in avalanches. Eight of those people have died, all backcountry skiers.

jromeo@durangoherald.com