There was a total of $12 million of farms, ranches, hunting land and other land for sale in Gregory County recently on Land.com. The total size of all Gregory County land and rural real estate for sale was almost 3,000 acres. Gregory County ranks 26th out of 66 counties in the Mount Rushmore State for the combined amount of land currently advertised for sale. Gregory featured the most land for sale. Agriculture and farming drives the Gregory County economy, with 505 farms recorded in the county during the U.S. Census in 2012. Farming activities in Gregory County generate annual revenues of $14 million, the majority of which comes from livestock products. Gregory County is South Dakota's 30th biggest county (1,053 square miles). It's located in the Great Lakes South Dakota region of the state.