There was a total of almost $7 million of land for sale in Piatt County recently on Land.com. The total acreage of all Piatt County land and rural real estate for sale was around 1,000 acres. Piatt County ranks 76th in the state for the total number of acres of land currently advertised for sale. Monticello featured the most land for sale. Piatt County has a large agricultural economy, with 426 farms recorded in the county during the latest U.S. Census. Farming activities in Piatt County generate annual revenues of $18 million, most of which is from crops. Piatt County is the 67th biggest county (439 square miles) in Illinois. It's located in the Central Illinois region of the state.