The Sauk (Sac) lived around the upper part of Green Bay and the lower Fox River in northeastern Wisconsin, but moved over a large part of eastern Wisconsin and northwestern Illinois during the historic period. Most of the Sauk now live with the Fox on the Sac and Fox Indian Reservation in Tama, Iowa; the Sac and Fox Tribe of Missouri (living in Kansas and Nebraska) ; and the former Sac and Fox Indian Reservation in east-central Oklahoma. They speak an Algonkian language.
Hagan, William T. (1958). The Sac and Fox Indians. Norman: University of Oklahoma Press.