A tree well is a significant, hidden hazard faced by skiers, snowboarders, and snowshoers who venture into areas with deep snow near trees. It is essentially a pocket of unstable, unconsolidated snow that forms around the base of a tree, particularly near dense evergreen varieties. This serious threat is often overlooked by winter recreationists who focus primarily on avalanches.
Defining the Hazard and How They Form
A tree well is a void of loose snow surrounding a tree trunk. This phenomenon occurs when a tree’s lower branches, especially those of conifers, create a sheltered canopy that prevents falling snow from consolidating near the trunk. The branches shield the area, meaning the snowpack around the tree is much lower and less dense than the snow farther away.
This “insulation effect” leaves a deep, often vertical, cylindrical hole filled with light, fluffy, unconsolidated snow instead of packed snow. The surface of this void is frequently concealed by the tree’s low-hanging boughs or a thin layer of surface snow. These wells can be surprisingly deep, sometimes extending as far as 20 feet in areas with substantial snow accumulation, creating a trap that is difficult to spot until someone has already fallen in.
Understanding the Extreme Danger of Tree Wells
Falling into a tree well is dangerous because the victim often falls headfirst, resulting in inversion. Once inverted, the loose, unstable snow collapses instantly around the person, quickly filling the space and compacting tightly due to the force of the fall and the victim’s weight. This sudden entrapment leads to Snow Immersion Suffocation (SIS), which is the primary cause of death in these incidents.
The danger is compounded by the loss of leverage in the loose snow, making self-extraction nearly impossible. Struggling or thrashing only causes more unconsolidated snow to settle and compact around the body, further restricting movement. Studies show that most people caught in this manner cannot rescue themselves. The rapid suffocation that follows can occur as quickly as drowning in water, emphasizing the narrow window for survival without immediate assistance.
Essential Safety Measures and Self-Rescue Techniques
Prevention is key to avoiding a tree well incident. Maintain a safe distance from tree trunks and their low-hanging branches when skiing or riding off-piste. Always venture into ungroomed or gladed terrain with a partner and maintain visual contact. If you lose sight of your partner, stop immediately and re-establish your position before continuing down the slope.
If you find yourself falling, immediately fight to stay upright and try to grab onto the tree trunk or any branches to prevent sliding deeper into the well. Once trapped, the immediate action is to create an air pocket around your face by clearing the snow. Then, remain calm to conserve both oxygen and energy, which is vital for survival. If you are inverted, use a whistle or your voice to signal your location.
If your partner falls into a tree well, do not leave them to get help, as time is extremely limited. Immediately begin rescue efforts by first assessing where their head is located. The safest method for extraction is to tunnel in from the side toward the victim’s head, being careful not to knock more snow onto them. Once the airway is cleared, continue expanding the tunnel until the victim can be safely pulled out. Never attempt to pull them out the way they fell in, as this risks further compaction.