Pennington County, South Dakota
Pennington 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°00′8.456″N 102°49′25.683″W / 44.00234889°N 102.82380083°W | |
| Country | United States |
| State | South Dakota |
| Founded | January 11, 1875 (created) April 19, 1877 (organized) |
| Named after | John L. Pennington |
| Seat | Rapid City |
| Largest city | Rapid City |
| Area | |
• Total | 2,784.459 sq mi (7,211.72 km2) |
| • Land | 2,776.765 sq mi (7,191.79 km2) |
| • Water | 7.694 sq mi (19.93 km2) 0.28% |
| Population (2020) | |
• Total | 109,222 |
• Estimate (2024) | 115,979 |
| • Density | 41.777/sq mi (16.130/km2) |
| Time zone | UTC−7 (Mountain) |
| • Summer (DST) | UTC−6 (MDT) |
| Congressional district | At-large |
| Website | pennco.org |
Pennington County is a county in the U.S. state of South Dakota. As of the 2020 census, the population was 109,222, making it the second most populous county in South Dakota, and was estimated to be 115,979 in 2024. Its county seat is Rapid City. The county was created on January 11, 1875, and was organized on April 19, 1877. It is named for John L. Pennington, fifth Governor of Dakota Territory, who held office in 1875 when the county was formed. Pennington County is included in the Rapid City metropolitan statistical area. It is also the location of Mount Rushmore.