List of counties in South Dakota

There are 66 counties in the U.S. state of South Dakota.
Todd County and Oglala Lakota County are two counties in South Dakota that do not have their own county seat. Hot Springs in Fall River County is the administrative center of Oglala Lakota County. Winner in Tripp County is the administrative center of Todd County. 
South Dakota's postal abbreviation is SD and its FIPS state code is 46.