Sioux County was created on 3 September 1914 from Standing Rock Reservation and part of the old Morton county. It was given a full set of officials by appointment of the then Governor, Louis B. Hanna, with Fort Yates designated as the county seat. It was named after the Native American Lakota, whose historic territory included this area and much more. It is located along the southern border of the North Dakota with an eastern border as the Missouri River. The county lies entirely within the Standing Rock Reservation, forming the northernmost 30 percent of the reservation (The balance of the reservation is in South Dakota). As of the 2010 census, the population was 4,153.

Standing Rock Reservation History Book - South of Cannonball - Sioux County History

Voices From the Western Frontier National Register Of Historical Places
Fort Yates
History Photos Digital Horizons
Lots of Sioux County pictures.
North Dakota State Historical Society Ghosts of North Dakota
Poorhouses In North Dakota Pictures Of Penny Postcards
The Record.
Historical magazine was published at Fargo, N.D. from 1895 to 1905. Focus on north Dakota historical and biographical articles. Index only. Order through NDSU.