Pennington County, South Dakota

Pennington County
Pennington County
County
	Pennington County Courthouse in Rapid City
	Location within the U.S. state of South Dakota
	South Dakota's location within the U.S.
	Coordinates: 44°01′N 102°49′W / 44.01°N 102.82°W
Country	United States
State	South Dakota
Founded	1875 (created); 1877 (organized)
Named for	John L. Pennington
Seat	Rapid City
Largest city	Rapid City
Area
• Total	2,784 sq mi (7,210 km2)
• Land	2,777 sq mi (7,190 km2)
• Water	7.8 sq mi (20 km2) 0.3%
Population (2020)
• Total	109,222
• Estimate (2023)	115,903
• Density	40/sq mi (20/km2)
Time zone	UTC−7 (Mountain)
• Summer (DST)	UTC−6 (MDT)
Congressional district	At-large
Website	www.co.pennington.sd.us

Pennington County is a county in the U.S. state of South Dakota. As of the 2020 census, the population was 109,222,^[1] making it the second most populous county in South Dakota. Its county seat is Rapid City.^[2] The county was created in 1875, and was organized in 1877.^[3] It is named for John L. Pennington, fifth Governor of Dakota Territory, who held office in 1875 when the county was formed.^[4]

Pennington County is included in the Rapid City metropolitan statistical area. It is also the location of Mount Rushmore.

^ "State & County QuickFacts". United States Census Bureau. Retrieved March 21, 2024.
^ "Find a County". National Association of Counties. Retrieved June 7, 2011.
^ "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.
^ "Pennington County, SD History" Archived October 22, 2013, at the Wayback Machine. Pennington County official website. Retrieved January 8, 2011.