There was a combined around $55 million of land for sale in Custer County recently on Land.com. The total of all Custer County farms and ranches for sale was around 3,000 acres. Custer County ranks sixth in the state for the total acreage of land currently advertised for sale. Custer featured the most land for sale. Government and state-level services are the main economic drivers in Custer County. Custer County is the 16th largest county (1,559 square miles) in South Dakota. It's located in the Black Hills & Badlands South Dakota region of South Dakota.