The fisher is a North American marten, a medium sized mustelid. The fisher is agile in trees and has a slender body that allows it to pursue prey into hollow trees or burrows in the ground. Despite its name, this animal seldom eats fish; the name may originate from the French word fichet, which referred to the pelt of a European polecat. In some regions the fisher is known as a pekan which is derived from its original name in the Abenaki language.
The fisher is found from the Sierra Nevada in California to the Appalachians in West Virginia and north to New England (where it is often called a fisher cat), as well as in southern Alaska and across most of Canada. Fishers are present in low density in the Rocky Mountains, where most populations are the result of reintroductions. There is recent evidence, however, that a Montana population persisted in a refugium despite extensive fur trapping in the area during the 1800s and 1900s. Fishers are most often found in coniferous or mixed forests with high, continuous canopy cover.