ASSINIBOIN, an American Indian tribe in the northern Plains, of Siouan affiliation, closely related in dialect to the Yank ton Dakota, but separately mentioned as early as 164o. Their habitat in the 17th century was about Lake Winnipeg, and in the 18th century on the upper Saskatchewan, where they ultimately gave its name to the province of Assiniboia. In the early 19th century they were estimated at from 6,000 to 10,000; in 1902–o4 they numbered 2,500, about equally divided between Canada and the United States. Culturally they belong with the Dakota and Plains Cree. See R. H. Lowie, Am. Mies. Nat. Hist. Anthr. Pap., vol. iv. (1909) .