Sully County, South Dakota

Sully County
Sully Courthouse (2013)
Sully Courthouse (2013)
Map of South Dakota highlighting Sully County
Location within the U.S. state of South Dakota
Map of the United States highlighting South Dakota
South Dakota's location within the U.S.
Coordinates: 44°43′N 100°08′W / 44.71°N 100.13°W / 44.71; -100.13
Country United States
State South Dakota
Founded1873 (created)
1883 (organized)
Named forAlfred Sully
SeatOnida
Largest cityOnida
Area
 • Total1,070 sq mi (2,800 km2)
 • Land1,007 sq mi (2,610 km2)
 • Water63 sq mi (160 km2)  5.9%
Population
 (2020)
 • Total1,446
 • Estimate 
(2023)
1,494 Increase
 • Density1.4/sq mi (0.52/km2)
Time zoneUTC−6 (Central)
 • Summer (DST)UTC−5 (CDT)
Congressional districtAt-large
Websitewww.sullycounty.net

Sully County is a county in the U.S. state of South Dakota. As of the 2020 census, the population was 1,446,[1] making it the fifth-least populous county in South Dakota. Its county seat is Onida.[2] The county was created in 1873 and organized in 1883.[3] It is named after General Alfred Sully, who built Fort Sully.[4]

Sully County is included in the Micropolitan Statistical Area of Pierre.

  1. ^ "State & County QuickFacts". United States Census Bureau. Retrieved March 20, 2024.
  2. ^ "Find a County". National Association of Counties. Retrieved June 7, 2011.
  3. ^ "Dakota Territory, South Dakota, and North Dakota: Individual County Chronologies". Dakota Territory Atlas of Historical County Boundaries. The Newberry Library. 2006. Archived from the original on April 2, 2018. Retrieved March 31, 2015.
  4. ^ Legislative Manual, South Dakota, 2005, p. 597.