what county is rapid city, sd located in?
Rapid City (Lakota: Mni LÃºzahaÅ OtÈÃºÅwahe; Swift Water City) is the second-largest city in South Dakota (after Sioux Falls) and the county seat of Pennington County. Named after Rapid Creek, on which the city is established, it is set against the eastern slope of the Black Hills mountain range.