Land for sale in Grant County recently totaled approximately $2 million and approximately 1,000 acres. Grant County ranks 41st in the state for the total acreage of land currently advertised for sale. Of all locations in Grant County with land for sale, Milbank featured the most land for sale. Grant County is South Dakota's 48th largest county (687 square miles). It's located in the Glacial Lakes & Prairies South Dakota region of the state.