My North Dakota Diary
'Sioux County was the last portion of the state to be originally organized into a county. The Standing
Rock Reservation comprised what is no Sioux county, North Dakota, and Carson County, South Dakota.
This whole Indian reservation was commonly called the Sioux Indian Reservation, so when this part was
made a county by proclamation of Governor Hanna on September 3, 1914, it was properly called Sioux
County with the approval of the white and Indian residents. The word Sioux is derived from the
Chippewa word, Nadowe-is-iw, or the French version of this word, Nadowes-sioux.' Source: North Dakota
Blue Book -- 1942