Plateau Sign Language

Plateau Sign Language
Native to	Canada, USA
Region	Columbia Plateau
Ethnicity	Various First Nations and Native Americans of the Columbia Plateau region
Extinct	18th century
Language family	contact pidgin
Writing system	none
Language codes
ISO 639-3	None (mis)
Glottolog	None
Attested historical range of Plateau Sign Language among other sign languages in the US and Canada (excl. ASL and LSQ).

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 Coleville), with western nations shifting instead to Chinook Jargon.