Sioux County is a county located along the southern border of the state of North Dakota. Based on the 2010 census, the population was
4,153. Its eastern border is the Missouri River and its county seat is Fort Yates. The county was created by proclamation of Governor Louis B.
Hanna on September 3, 1914 and named after the Native American Lakota, whose historic territory included this area and much more. The county
government was first organized on September 12, 1914.
The county lies entirely within the Standing Rock Indian Reservation, forming the northernmost 30 percent of the reservation. (The balance of
the reservation is in South Dakota). It is the only county in North Dakota that is entirely within an Indian reservation.
Sioux County is included in the Bismarck, ND Metropolitan Statistical Area.
Named for Dakota or Sioux Indians who inhabited the reservation.
County QuickFacts: CensusBureau Quick Facts
Created by proclamation of Gov. Louis B. Hanna on September 3, 1914, from the area encompassed by the Standing Rock Indian Reservation in North Dakota. Named for Dakota or Sioux Indians who inhabited the reservation. Government organized: September 12, 1914. County Seat: Ft. Yates, 1914-present.
As reported by the Census Bureau, the county has a total area of 1,128 square miles (2,920 km2), of which 1,094 square miles (2,830 km2) is land and 34 square miles (88 km2) (3.0%) is water
Bordering counties are as follows: