A tree well is a hidden void or depression that forms around the base of a tree in areas with significant snowfall. This space, composed of loose snow, air, and sometimes low-hanging branches, poses a hazard to individuals in forested, snow-covered environments. These formations are a danger, especially for skiers, snowboarders, and snowmobilers venturing into ungroomed terrain.
Understanding Tree Well Formation
Tree wells develop due to how snow interacts with tree structures. Coniferous trees, such as firs and hemlocks, have branches that extend outward and downward, creating a canopy effect. This canopy intercepts falling snow, preventing it from accumulating directly around the tree’s trunk, leaving a less dense or hollow space at the base.
The snow within a tree well remains unconsolidated and lacks the stability of packed snow. This void can deepen with increased snowfall, sometimes reaching depths of up to 20 feet in large forests. The tree trunk can also radiate a small amount of heat, contributing to this unstable snowpack. This creates an inverted cone shape, wider at the bottom, which can conceal the well’s true depth.
The Dangers of Tree Wells
Tree wells are hazardous because they can trap a person, often leading to snow immersion suffocation (SIS). When someone falls into a tree well, they frequently go in headfirst, becoming disoriented and inverted. The unconsolidated snow acts like quicksand, making it difficult to self-extricate or gain leverage. This struggle can cause more snow to collapse from above, further burying the individual.
Suffocation results when snow packs tightly around the victim, obstructing the airway or compressing the chest. In an inverted position, breathing becomes difficult, and the body’s struggle can worsen the situation by pushing more snow into the airway or deepening the burial. Hypothermia also poses a risk, as prolonged exposure in cold, wet snow can rapidly lower body temperature, impairing judgment and physical ability. Up to 90% of individuals who fall into a tree well cannot rescue themselves without assistance.
Prevention and Self-Rescue Strategies
Preventing a tree well incident begins with awareness and planning. Always ski or snowboard with a partner, maintaining visual contact, especially in ungroomed terrain or gladed areas. Treat all trees as potential hazards, as tree wells can be difficult to identify due to concealment by low-hanging branches. Remaining on groomed trails significantly reduces the risk of encountering these voids.
If you fall into a tree well, attempt to grab the tree trunk or any available branches to stop your descent. Resist the urge to struggle or thrash, as this can cause more snow to collapse around you. Instead, create an air pocket around your face and mouth to ensure you can breathe. Yell loudly or use a whistle to alert your partner to your location.
If your partner falls into a tree well, do not leave them to seek help. Immediately begin rescue efforts while calling for additional assistance if possible. Prioritize clearing snow from their airway, being careful not to dislodge more snow into the well. Dig from the side or below towards their head, rather than attempting to pull them out from the direction they fell in, as this can cause further injury or re-burial. Create a safe pathway to extricate them from the snow.