Plateau Sign Language

Plateau Sign Language, or Old Plateau Sign Language, is a poorly attested, extinct sign language historically used across the Columbian Plateau. The Crow Nation introduced Plains Sign Talk, which replaced Plateau Sign Language among the eastern nations that used it (the Coeur d’Alene, Sanpoil, Okanagan, Thompson, Lakes, Shuswap, and Colville), with western nations shifting instead to Chinook Jargon.