Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Perkins County is a county located in the U.S. state of South Dakota. As of 2000, the population was 3,363. Its county seat is Bison. It is, in area, the second largest county in South Dakota, its size being exceeded only by Meade County. According to the U.S. Census Bureau, the county has a total area of 2,891 square miles (7,487 km²), of which, 2,872 square miles (7,437 km²) of it is land and 19 square miles (49 km²) of it (0.66%) is water.