The value of all land for sale in Gregory County, South Dakota, recently was almost $41 million, representing a combined 8,214 acres of land for sale in Gregory County. Gregory County ranks 20th in the Coyote State based on the total acres of land for sale of the 66 counties in the Mount Rushmore State. Fairfax featured the most land for sale. Its economy is defined as agricultural, with 505 farms recorded in the county during the most recent U.S. Census. 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 South Dakota.