Chinook (shĭnŏkˈ, chĭ–) [key], Native American tribe of the Penutian linguistic stock. Altogether twelve main tribes spoke Chinook languages; all were in the Columbia River valley. The Chinook themselves were on the lower extremity of the river and, with the Clatsop, constituted the now extinct Lower Chinook branch of the linguistic stock (see Native American languages). The village was their main social unit, and a wealthy chief might control several villages. Slavery was common among the Chinook. Their food consisted mostly of fish, roots, and berries. They were skilled with canoes, were noted traders, and practiced the custom of potlatch. They lacked the totemic art and the secret societies of their neighbors. They were well known to the traders on the Pacific coast in the late 18th cent., and a corrupted form of their language known as Chinook jargon served as a trade language from the Columbia River to Alaska. There were some 800 Chinook in the United States in 1990, working primarily in fishing, logging, and lumbering.