When navigating in the backcountry and especially when navigating offtrail, a handrail refers to a feature you can follow towards your intended destination while maintaining accurate knowledge of your location, at least along one axis. Examples of handrails include rivers and streams (the most classic example), a fence or power line, a specific altitude in mountainous terrain, the shoreline of a large body of water, a linear canyon, or even other man-made features such as roads.
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