Abstract Four machines were observed during over-story removal of conifer stands in Idaho by two methods: skidding of whole trees on undesignated trails, and skidding of tree lengths on trails designated in advance. A rubber-tired skidder handling whole trees had the lowest costs, $19 per cunit at an average skidding distance of 530 feet, and the highest production, 37.1 cunits per day. Least production, 22.6 cunits per day, was with a crawler tractor of low horsepower. A crawler of medium power and a torsion-bar track machine were intermediate in cunit production. Output was generally increased when tree lengths were skidded on designated trails, but costs per cunit varied with machine productivity. Designation of trails somewhat lessened the damage to advance reproduction and reduced the roaded area by almost half.