Avalanche Accident in Tuckerman Ravine

Two hikers descending from the summit triggered an avalanche that carried them down the Lip of Tuckerman Ravine.  In this incident, a group of four hikers started up from Pinkham Notch Visitor Center. Along the ascent, the group separated into two teams of two. Descending in poor visibility and fading daylight, the faster team lost the trail and inadvertently began descending the Lip. This forecast area had been rated Considerable avalanche danger due to expected wind loading late in the day. The slower team, realizing the other party had gone off trail, followed their tracks to the crown line of the avalanche. From there they were able to verbally communicate with their friends and learn the extent of the injuries. They decided it would be safer to descend the Lion Head Summer Trail to summon assistance.

As an avalanche forecasting center, we were not surprised that the party triggered an avalanche in the location they did. Considerable danger includes “human triggered avalanches are likely” in its definition. Weather conditions in the days prior to the accident created conditions ripe for avalanche activity. About a week before the accident, Mt. Washington was subjected to a warm rain event. This created slick crusty snow surface conditions for future snow and wind-loading land on and create new stability problems. In the 48 hours prior to the event, about 10.5” of new snow had fallen, with 1-3” having been forecasted for the 28th. During this time, west and northwest winds also increased in speed from 30-40mph to 60-80mph. This created a situation with increasingly dense slab building on top of weaker layers, all of which sat on the pre-existing crust.  This is a typical scenario for Mt. Washington; one in which we regularly see human triggered or naturally triggered avalanches.

The hikers rode the avalanche to the base of the Open Book, adjacent to Lunch Rocks. Along the way they sustained non-lifethreatening injuries. In the debris, they ended up only partially buried or on top of the snow, one was at the toe of the debris and the other at the top of the debris. They reported taking about a half hour to collect themselves and figure out what happened. They also did not understand where exactly they were, or that the Tuckerman Ravine Trail could be followed downhill from their location. They knew they had fallen a long way below the trail they intended to descend, so they began to climb back up, which is when they began communicating with their friends above.

The uninjured hikers arrived at the AMC Caretaker’s quarters to tell her of the accident. She quickly notified USFS Snow Rangers, who began mobilizing rescue teams. Rescuers included USFS Snow Rangers, members of Mountain Rescue Service and Androscoggin Valley Search and Rescue, caretakers from the AMC and HMC cabin, and a handful of helpful bystanders who were staying overnight at the Harvard Cabin. The rescue itself was not particularly noteworthy. A rescue team climbed to the injured hikers, assessed and treated their injuries, and short-roped them down to the floor of Tuckerman. From there the hikers walked down under their own power to Hermit Lake to a waiting snow tractor. They were then transferred to an ambulance at the bottom of the Sherburne Ski Trail.

Analysis:

This is an accident that could have been avoided if just a couple small factors played out differently. Most obviously, if the group had stayed together and stayed on the Lion Head Trail, they would never have entered avalanche terrain.  The two more experienced hikers had been planning to do an overnight at Hermit Lake, while the two with less experience were only doing a day trip. Hence, the two with lightweight daypacks were able to move more quickly than the heavily-laden duo. This was the primary reason for one group going faster than the other, as we understand. The plan had been for the hikers to all regroup at the summit, but the faster group went down ahead. Often in incidents involving missing or overdue hikers, splitting the group is a contributing factor. Many times there is no contingency plan made, or if there is one it is not followed. In this event we don’t know exactly what their meeting plan was. However, if they had either kept the group together for the duration, or stuck with the plan to regroup,  the chances for staying on the trail and avoiding the incident would have been better.