trailO

TrailO, or Trail Orienteering, is a discipline of orienteering that concentrates on the precise identification of terrain features from a map and control descriptions, rather than navigation at speed. Competitors traverse a course consisting of a series of controls; at each control, they must decide which ground feature at the location corresponds to the description on the map. The control descriptions specify the intended feature (for example, a boulder on a slope, a small reentrant, or a mound) and are used to distinguish the correct feature from decoys placed nearby. The emphasis is on careful observation, map interpretation, and decision making, and courses are designed to be accessible to a wide range of abilities, including visually impaired athletes in some formats.

TrailO uses standardized formats, with the most common being Line-O and Position-O, though other formats exist. In Line-O, the contestant must determine whether a feature lies on a specified line on the map; in Position-O, the correct feature must be identified from among several candidates. The sport is governed internationally by the International Trail Orienteering Federation (ITOF), which organizes the World Trail Orienteering Championships (WTOC) and sets rules for national and international events. National federations run local events that feed into regional and world-level competition.

TrailO has evolved as a bridge between traditional orienteering and accessibility, allowing participation irrespective of running speed or endurance in many formats while maintaining rigorous map-reading challenges.