There was a combined $15 million of farms, ranches, and rural real estate for sale in Riley County recently on Land.com. The total acreage of all Riley County farms and ranches for sale was nearly 1,000 acres. Riley County ranks 59th out of 105 counties in the Sunflower State for the total acreage of land currently advertised for sale. Of all farms, ranches, hunting land and other land for sale in Riley County, Manhattan had the most land for sale. From an economic perspective, government and state-level services contribute most to Riley County's overall GDP. Riley County is the 81st biggest county (622 square miles) in Kansas. It's located in the Tallgrass Prairie Kansas region of the state.