A technique in forest harvesting by which logs or whole trees are dragged over the ground, as opposed to being lifted in the air, to a landing, where they are loaded on trucks for transport to a mill. The logs may be dragged by mechanical means, such as a crawler tractor or rubber-tired skidder, or by draft animals. Skidding normally disturbs the ground surface and forms "skid trails" which may be used once or reused in subsequent harvests. Soil in skid trails, especially on steep land, may channel water flow during rainfall and snow melt and be susceptible to erosion.