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 Tribe 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^[which?] shifting instead to Chinook Jargon.^[1]

Plateau Sign Language
Langue des Signes du Plateau
Native to	Canada, United States
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
Maps of the various sign languages of Turtle Island (North America), excluding Francosign languages. Plateau Sign Language is labelled in orange as "PSL"

Further reading

• Mallery, Garrick (1881). "Sign Language Among North American Indians Compared With That Among Other Peoples And Deaf-Mutes". First Annual Report of the Bureau of Ethnology to the Secretary of the Smithsonian Institution, 1879-1880. Washington: Government Printing Office. pp. 263–552 – via Project Gutenberg.
• Clark, William Philo (1885). The Indian Sign Language – via Google Books.