American marten (Martes americana (Turton, 1806)) was traditionally associated with old-growth forests, but recent evidence suggests that they are frequently found in younger forests as well. To better understand habitat requirements by this economically important furbearer, we investigated its fine-scale movement behavior in relation to local prey activity (tracks) and stand age. We georeferenced 34 marten tracks (57 km), associated prey tracks, and subnivean forays in a balsam fir forest of southern Québec, Canada. Marten movements were more tortuous in the presence of high numbers of prey tracks and near subnivean foraging sites. The latter relationships were stronger at a fine spatial scale (10 m movement steps) than at coarser scales (20 or 40 m movement steps). Marten movement tortuosity was unrelated to forest stand age after accounting for prey activity. These results support the hypothesis that the American marten does not hunt mainly in old-growth forests but appears to concentrate its foraging behaviour in areas with high prey activity.