Back to back skier triggered avalanches in the Lower Snowfields and Hillman’s Highway

Back to back skier triggered avalanches in the Lower Snowfields and Hillman’s Highway resulted in one injury. Around 1230 a party of three were skinning up the Lower Snowfields. One person decided to head down while the other two continued up. The top skier stopped at the top of the “Christmas tree” for a break when he heard his remaining partner yell, “slide!”. Prior to the slide, both individuals observed shooting cracks propagating from their skis. The lower of the two people was caught and carried about 750 feet down the Lower Snowfields (D2R3*). During the ride, the victim swam feet first in an attempt to stay on top of the debris. At one point he hit a tree with his upper right ribcage. Debris momentarily went over his head and his mouth was packed with snow. When he stopped he was on his back and partially buried. He self extricated and a bystander showed up shortly after to help him. U.S. Forest Service Snow Rangers, members of the Mt. Washington Volunteer Ski Patrol and Mountain Rescue Service responded and were on scene in 20 minutes. The priority was to help the victim and assure no other people were caught in the slide. An initial search, a beacon search and thorough interviews with witnesses were conducted. The patient was able to walk to Hermit Lake under his own power where he was reassessed and transported down to Pinkham Notch via snowmobile.

Forty-three minutes after the initial avalanche, another one occurred in Hillman’s Highway (D3R3). Response time was immediate due to the proximity of the rescue crew working in the Lower Snowfields. Six people were in the gully at the time of the avalanche and some reported that it came from the top and was a natural avalanche. Confirmation of a natural avalanche was difficult due to low clouds and blowing snow. All witnesses stated that nobody was caught in the avalanche. With enough uncertainty about this fact, we conduced an initial search, a beacon search, a Recco search and a dog search. A probe team was mobilized to the area and held out of avalanche terrain for safety reasons. Clouds cleared and the fracture line became visible in the middle of Hillman’s Highway allowing us to confirm that the trigger was likely a person. We were able to deduce this due to the odd location of the fracture line, the suspicious amount of hangfire left above and the proximity of the people in the gully to the fracture line. Witnesses and bystanders stated that no one was missing and that they believed no one was caught. Based on this information and significant scene safety concerns we called off the search. Safety concerns included the instability of adjacent slide paths that run into the bottom of Hillman’s and the large amount of unstable snow left above the fracture line in Hillman’s, which included both of it’s primary start zones.

We are very happy that more people were not injured and no one was killed in these incidents, as this could have been a plausible outcome. Statistically, most avalanche accidents occur under Moderate and Considerable ratings. On this day, the Lower Snowfields were rated Moderate and Hillman’s Highway was rated Considerable. Both of these ratings state the potential for human triggered avalanches as being possible and probable respectively.

* “D” represents the destructive force of the avalanche on a scale of 1-5. “R” represents the size of the avalanche relative to the path, also represented on a scale of 1-5.