CAIC: Colorado Avalanche Information Center

2016/01/16 - Colorado - Hagerman Pass

Published 2016/01/19 by Ethan Greene - Forecaster, CAIC


Avalanche Details

  • Location: Hagerman Pass
  • State: Colorado
  • Date: 2016/01/16
  • Time: 12:30 PM (Estimated)
  • Summary Description: Two skiers caught and partially buried, one injured.
  • Primary Activity: Backcountry Tourer
  • Primary Travel Mode: Ski
  • Location Setting: Backcountry

Number

  • Caught: 2
  • Partially Buried, Non-Critical: 2
  • Partially Buried, Critical: 0
  • Fully Buried: 0
  • Injured: 1
  • Killed: 0

Avalanche

  • Type: SS
  • Trigger: AS - Skier
  • Trigger (subcode): u - An unintentional release
  • Size - Relative to Path: --
  • Size - Destructive Force: --
  • Sliding Surface: Unknown

Site

  • Slope Aspect: S
  • Site Elevation: 11800 ft
  • Slope Angle: --
  • Slope Characteristic: --

Avalanche Comments

The avalanche occurred during a storm event with heavy snowfall and strong winds. The party relayed estimates of the size to the CAIC investigator, but the investigator and rescuers did not visit the site of the avalanche. We can make an educated guess of the character of the avalanche given our knowledge of the snowpack prior to the incident and weather during the event. The slide probably broke at the new/old snow interface releasing as a soft slab avalanche. The slab probably formed during the period of intense snow transport described by the group. The avalanche was certainly large enough to kill people (D2), but probably not large enough to destroy a timber structure (D3). The avalanche was likely relatively small compared to what the slope could produce (R2). The avalanche was unintentionally triggered by skiers (SS-ASu-R2D2-O).

Weather Summary

A winter storm moved into the Sawatch Range late on January 14th. The Brumley SNOTEL site (10,601 feet on the east side of Independence Pass) and Fremont SNOTEL site (northwest of the top of Fremont Pass at 11,400 feet) each had one inch of new snow on the morning of January 15th. The storm progressed during the day with more snow and west to northwest winds in the 10 to 20 mph range. On the morning of January 16th, there was an additional 4 inches of new snow at both the Brumley and Fremont SNOTEL sites. Snowfall, heavy at times, continued through the day with northwest winds in the 20 to 30 mph range with gusts in the 40s and 50s. By the morning of January 17th, an additional 6 inches of new snow had accumulated at the two SNOTEL sites. 

There are no manual or automated weather stations in the area where the accident occurred. Based on conditions we observed on January 17th and the description from the party, significantly more snow fell around the Skinner Hut, with very strong westerly winds over Hagerman Pass. 

Snowpack Summary

The snowpack in the Sawatch Range began to build in late October. The snow on the ground remained quite shallow through November with about one significant storm event each week. The snowpack was already thin and weak when a dry period arrived in early December. A series of storms in late December and early January built layers of new and wind-drifted snow on top of a weak, faceted foundation. These storms produced a significant avalanche cycle in the Sawatch zone between December 25th and January 1st. Another extended period of dry weather produced weak faceted snow on and near the snow surface in early January. By January 14th, the snowpack consisted of several layers of weak faceted snow. In many near and below treeline areas the snowpack could barely support the weight of a skier or snowmobiler.  

Events Leading to the Avalanche

Two skiers planned a multi-day traverse from the trailhead on USFS Road 505, to the Betty Bear Hut, the Skinner Hut, and then to the Turquoise Lake trailhead. They traveled to the Betty Bear Hut on January 15, 2016. The next day they began a traverse over Hagerman Pass and to the Skinner Hut. As they crossed the pass they encountered strong winds and blowing snow. These conditions made it difficult to communicate and navigate. The visibility ranged from around 1/8th of a mile to less than a few feet. The pair followed the summer road over the pass. They moved across a narrow terrain feature on the east side, following the summer road as it heads towards a rocky knob. Here the road turns to the north, but the two skiers inadvertently moved to the south onto steeper terrain above Hagerman Lake. They were aware that the blowing snow was loading slopes to the lee of the pass and increasing the avalanche danger. Their equipment was still in uphill mode, with climbing skins on their skis and bindings set for touring, as they followed the terrain, in poor visibility onto steeper slopes.  

Accident Summary

The two skiers followed the terrain as in gradually steepened and lead them downhill. They noticed sluffing in the new snow and then felt the snow moving around them and pushing on the back of their legs. The avalanche knocked both skiers off of their feet and they fell forward. They swam to try to stay on top of the moving debris. They went under and then fought their way to the surface several times. The debris slowed as it came to a bench in the terrain. When it stopped, Skier 1 was partially buried with his head and both arms above the snow. Skier 2 had his head and one arm free.

Rescue Summary

Skier 1 was able to dig out his pack and get out his shovel. He dug himself out of the snow. Skier 1 was injured and had lost both poles. Though injured, he was able to move over to Skier 2. Skier 2's legs were under about six feet of snow and needed help to extricate himself from the debris. Skier 2 was uninjured, but lost both poles and one ski. The two knew the winds were still moving snow onto the slopes above them. They decided to descent to the low-angle terrain below Hagerman Lake ( about 11,300 feet). They followed the low-angle terrain to the east and eventually ascended to the Skinner Hut (11,620 feet). The avalanche released about 12:30 PM and the two reached the hut about 8:30 PM. There were several other groups at the hut. They called the Lake County Sheriff's dispatch center and reported the accident. On January 17th, Lake County Search and Rescue traveled to the Skinner Hut, provided medical treatment to Skier 1, and transported Skiers 1 and 2 to the Turquoise Lake trailhead.

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