Walworth County, South Dakota

Walworth County
County
Walworth County Courthouse, Selby
Walworth County Courthouse, Selby
Map of South Dakota highlighting Walworth 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: 45°26′N 100°02′W / 45.43°N 100.03°W / 45.43; -100.03
Country United States
State South Dakota
Founded1873 (created)
1883 (organized)
Named forWalworth County, Wisconsin
SeatSelby
Largest cityMobridge
Area
 • Total
745 sq mi (1,930 km2)
 • Land709 sq mi (1,840 km2)
 • Water36 sq mi (90 km2)  4.8%
Population
 (2020)
 • Total
5,315
 • Estimate 
(2023)
5,269 Decrease
 • Density7.1/sq mi (2.8/km2)
Time zoneUTC−6 (Central)
 • Summer (DST)UTC−5 (CDT)
Congressional districtAt-large
Websitewalworthco.org

Walworth County is a county in the U.S. state of South Dakota. As of the 2020 census, the population was 5,315.[1] Its county seat is Selby.[2] The county was created in 1873 and organized in 1883.[3] It is named for Walworth County, Wisconsin.[4]

flows southward along the county's west boundary line. Swan Creek flows west-northwest through the county's SW corner, discharging into the Missouri. The county's terrain consists of semi-arid rolling hills, carved by drainages and gullies. Most of the area is devoted to agriculture.[5] The terrain slopes to the south and east, although the western portion of the county drops westward into the Missouri River valley. The county's highest point is on the eastern portion of its north boundary line, at 1,982 ft (604 m) ASL.[6] The county has a total area of 745 square miles (1,930 km2), of which 709 square miles (1,840 km2) is land and 36 square miles (93 km2) (4.8%) is water.[7]

The eastern portion of South Dakota's counties (48 of 66) observe Central Time; the western counties (18 of 66) observe Mountain Time. Walworth County is the westernmost of the SD counties to observe Central Time.[8]

  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
  5. ^ "Walworth County · South Dakota". Google Maps. Retrieved April 27, 2024.
  6. ^ ""Find an Altitude" Google Maps (accessed February 9, 2019)". Archived from the original on May 21, 2019. Retrieved February 10, 2019.
  7. ^ "2010 Census Gazetteer Files". United States Census Bureau. August 22, 2012. Retrieved March 28, 2015.
  8. ^ Map of Time Zone Line through South Dakota (accessed January 30, 2019)