A total of nearly 1,000 acres were listed for sale in Grant County, South Dakota, recently, representing a combined almost $7 million in Grant County farms, ranches, hunting land and other land for sale. Grant County ranks 30th in South Dakota for the total acreage of land currently advertised for sale. Milbank had the most land for sale. Grant County is the 48th largest county (687 square miles) in South Dakota. It's located in the Glacial Lakes & Prairies South Dakota region of the state.