- Location: South of Red Mountain Pass, Sam's Trees
- State: Colorado
- Date: 2018/01/21
- Summary Description: 2 backcountry skiers caught and partially buried, 1 killed
- Primary Activity: Backcountry Tourer
- Primary Travel Mode: Ski
- Location Setting: Backcountry
- Caught: 2
- Partially Buried, Non-Critical: 1
- Partially Buried, Critical: 1
- Fully Buried: 0
- Injured: 0
- Killed: 1
- Type: SS
- Trigger: AS - Skier
- Trigger (subcode): u - An unintentional release
- Size - Relative to Path: R3
- Size - Destructive Force: D2
- Sliding Surface: O - Within Old Snow
- Slope Aspect: NE
- Site Elevation: 11092 ft
- Slope Angle: 38 °
- Slope Characteristic: Convex Slope
This was a skier-triggered, soft slab avalanche that was medium-sized relative to the path, and had the destructive force to bury, injure or kill a person (SS-AS-R3-D2-O/G). The avalanche failed on a layer of faceted, early-season snow near the ground, and released the entire season’s snowpack. The crown face was 18 to 22 inches deep and 240 feet across. The avalanche initiated on the steep, north-facing slope that forms the skier’s right side of the gully the group was descending. The fracture crossed the slope, and then continued down the ridgeline that formed the south side of the gully, resulting in a large slide that entrained a significant amount of snow. The avalanche broke at a subtle, mid-slope convexity, leaving a significant amount of snow in the start zone, and lingering hazard above the fracture line. A smaller avalanche was triggered sympathetically from the side of the gully as the debris ran by. The terrain in the track was open glades with some brush and aspen clumps. The force of the slide was insufficient to cause significant damage to the vegetation in the track.
The CAIC maintains the Red Mountain Pass snow study site approximately 1 mile north and roughly the same elevation of the accident site (11,070 ft). Forecasters measured 8 inches of snow and 0.45 inches snow water equivalent on the morning of January 21st. The Swamp Angel automated weather station, located just north of Red Mountain Pass at 11,050 ft, reported 10 inches of snow and 0.7 inches of snow water equivalent during the same period. Moderate to heavy snowfall continued through the day with temperatures in the single digits.
Winds at the Eagle automated weather station, located on a ridge top (12,852 ft) above the accident site, recorded southerly winds with hourly averages between 10 and 45 mph on January 20. The wind veered to the northwest by 9:00 AM on the 21st, blowing 20 to 30 mph with gusts between 34 to 53 mph through the day.
The weather during the week prior to the incident was mild and dry with daytime temperatures reaching above freezing several days at Red Mountain Pass. Nighttime low temperatures ranged from the single digits to low twenties. The week of January 7 to 14 was the stormiest of the season to date with 43 inches of snow and 3.4 inches snow water equivalent measured at the Red Mountain Pass snow study site. Prior to January 7, the snowfall in the region was historically low, with a total of only 17.5 inches and 1.2 inches snow water equivalent measured at the Red Mountain site during both November and December combined.
The total depth of the snowpack in the area of the accident ranged from about 40 cm to 60 cm. The avalanche slid on a crust/facet interface above a layer of depth hoar near the ground. The mid-pack was composed of rounded grains turning to faceted grains from the January 10th and 11th storm and the upper snowpack was the new snow from the January 20th and 21st storm.
Snowpack tests in a profile observed adjacent to the crown showed that cracks could easily propagate along the slab weak-layer interface. An Extended Column Test crack propagated across the column on tap number 13 (ECTP13). A Propagation Saw Test propagated to the end of the column (30/90 End) on a layer 45 cm below the surface, and a Compression Test failed in sudden collapsed in the depth hoar on tap 11 (CTM11SC).
There were other avalanches of similar depth on the same slope at a lower elevations, and to the southeast on a ridge above the accident site. Other backcountry users in the area site reported whumpfing and shooting cracks in flat areas in the valley and close to tree line on east and northeast aspects.
Events Leading to the Avalanche
Skiers 1 and 2 met at Purgatory Ski Area at 10:10AM and drove up to Red Mountain Pass together. On the way up they looked at the Colorado Avalanche Information Center (CAIC) forecast and developed a plan for where they would tour based on current conditions. They chose to ski Sam’s Trees and discussed the recent avalanche activity resulting from the January 10th and 11th storm. They did a beacon search at their vehicle and began skinning up at 11:45 AM. On their way up the skin track they continued discussing their descent plans. Both agreed to ski the northern ridgeline (center rib of Sam’s) and to avoid the first steep pitch.
As they descended, Skier 1 released a small (D1) avalanche without his knowledge. Skier 2 witnessed this and reported the slide to Skier 1. They met up and re-evaluated their plan. They decided they would continue down the center rib, avoiding the gully to the skier’s left. After leapfrogging and keeping each other within visual contact, Skier 1 stopped at a group of trees. Skier 2 then skied past him, accidentally drifting left of the center rib into the gully that they had discussed avoiding. Skier 2 stopped somewhere in the gully. Skier 1 proceeded downhill past Skier 2’s presumed location. Soon after, Skier 1 decided to slow down to see where Skier 2 was. This is when Skier 1 felt and saw snow flowing around his legs, pushing him downhill.
The avalanche that hit Skier 1 first was probably the smaller of the two slides. It pushed him 50 to 60 ft downhill, but he was able to ski out to the skier’s right and stop. Before he could turn around he was hit by a second wave of snow about waist high and it knocked him over and pushed him another 50 to 60 feet downhill. He was moving head first downhill, struggling to keep his head above the debris. Skier 1 saw a small spruce tree and managed to grab and hold on as the snow rushed past. The moving snow released his skis and kept sliding by him for several seconds before stopping, leaving him buried to his waist. Skier 1 yelled Skier 2’s name several times and started digging himself out. Not hearing a response from Skier 2, he looked at his watch and noted the time as 1:20 PM. Skier 1 immediately took his cell phone out to call 911, but he did not have cell service and was unable to make the call.
After Skier 1 dug himself out of the snow, he began screaming for help. He fired three rounds from a .22 caliber pistol into the air hoping to attract the attention of anyone nearby. He pulled out his transceiver and switched it into search mode. His beacon was not receiving a signal, and he guessed Skier 2 was on the slope above him. He crawled uphill through the soft debris about 10 feet to get on the avalanche bed surface. Once on the bed surface he checked his transceiver again--still no signal--so he continued uphill another 20 feet before receiving a signal from Skier 2's transceiver. He followed the signal until the display read 3 meters and he began a pinpoint search. A few moments later he noticed a glove sticking out of the snow a few feet to his right.
With his shovel, Skier 1 began digging in the area he though Skier 2’s head was based on the orientation of the protruding hand. Skier 1 reached Skier 2’s head and uncovered his face and chest and noted the time as 1:28 PM. Skier 2 was buried face up (supine position) with his head about 3 feet below the surface. His legs were higher than his head, but buried about 5 feet deep under a mound of debris. Skier 2 was not breathing and unresponsive. Skier 1 removed his glove and checked Skier 2 for a pulse. He did not feel one. Skier 1 began rescue breaths but was unable to adequately ventilate Skier 2. He calmed himself for a moment and made two stronger breaths and noted Skier 2’s chest rise and fall each time. Skier 1 proceeded to start CPR. After 10-14 cycles of chest compressions, Skier 1 decided he needed to change his focus and attempt to find help.
Skier 1 grabbed his backpack and shovel and headed down the gully screaming “Help!”. After 90-100 yards downhill he got a response from another party of two skiers--Skiers 3 and 4. A separate, solo tourer--Rider 5--also responded to the calls. Yelling back and forth, they decided the Rider 5 would descend to the highway and call 911 for help. Rider 5 made the call at 2:24 PM.
Skier 1 climbed back to Skier 2 and resumed CPR. After about 20 minutes Skiers 3 and 4 reached the accident location. Skier 3 assessed the situation and decided they should move Skier 2 due to the potential for additional avalanches. They all agreed and moved Skier 2 to a safer location about 20 feet to the north. At the safer site they built a platform in the snow and continued CPR.
With CPR ongoing, they decided Skier 4 should descend to the highway to help Search and Rescue (SAR) locate the accident site. After 20 minutes passed, there was no sign of SAR. Skier 3 began to worry that Skier 4 did not make it to the highway safely, and Skier 3 descended to determine if Skier 3 had. Skier 4 had indeed safely arrived at the highway. The decision for Skier 3 to leave the accident took place at 3:45 PM.
Skier 1 continued CPR alone until SAR arrived on scene at 4:40 PM. Rescuers packaged Skier 2 in a rescue sled and began transporting him downhill following hypothermia protocols of 5 minutes of compressions and 5 minutes of transport. Rescuers reached the bottom of Sam’s Trees at 5:50 PM, and a snowmobile team took Skier 2 to an ambulance waiting on the highway.
Both Skiers 1 and 2 read the current CAIC avalanche forecast that morning. They discussed and developed a plan to avoid steeper slopes and certain aspects. They noted recent avalanche activity. Despite these discussions they still ended up in terrain they had planned to avoid. There can be many reasons for this: bad visibility, the lure of powder, losing orientation on the slope…whatever the reason, it is not an uncommon experience for backcountry travelers. Reviewing the accident photos, Skier 1 was surprised at how far off their planned route they ended up.
Their decision to ski in this particular area was also influenced by the presence of other vehicles parked at the trailhead. This reaffirmed their discussions that it would be a good place to ski that day.
The slope that avalanched was relatively small, but the snow slid into a tight gully with sparse trees. Debris piled up deeper in the terrain trap than if it had run on a broad, open slope.
Figure 12: Fracture line profile dug into the crown of the avalanche on a north-northeast aspect at 11,110' ASL. Snowpit tests produced moderate results despite the slope having previously collapsed.