A combined 1,000 acres were listed for sale in Riley County recently; the overall value of all Riley County land and rural real estate for sale was around $18 million. Riley County ranks 43rd out of 105 counties in Kansas for the combined amount of land currently advertised for sale. Of all locations in Riley County with land for sale, Manhattan had the most land for sale. Government and state-level services are the main economic drivers in Riley County. Riley County is the 81st biggest county (622 square miles) in Kansas. It's located in the Tallgrass Prairie Kansas region of the state.