The value of land for sale in Grant County recently on Land.com was almost $2 million. This represents 1,000 acres of land and rural real estate for sale in Grant County. Grant County ranks 37th out of 66 counties in the Mount Rushmore State for the combined amount of land currently advertised for sale. Of all ranches, farms, hunting land and other rural land and acreage for sale in Grant County, Milbank had the most land for sale. Grant County is South Dakota's 48th biggest county (687 square miles). It's located in the Glacial Lakes & Prairies South Dakota region of South Dakota.