18,800 in United States (2010 census), decreasing. 31 monolinguals (1990 census). 25,000 L1 speakers of all Sioux dialects in a total population of 103,000 (Golla 2007). Population total all countries: 20,460. Ethnic population: 5,000 Yanktonais (1997 D. Parks); 20,475 (2000 census).
Several widely dispersed reservation communities in Minnesota, eastern Nebraska and the Dakotas; South Dakota, Yankton and Crow Creek reservations; North Dakota, northern Standing Rock Reservation, Devils Lake and Fort Peck reservations. Also in Canada.
Most youth prefer English [eng] or do not speak the language. Teaching programs at every level, preschool through university (2007). Few children (1998).