There was a combined approximately $43 million of farms, ranches, hunting land and other land for sale in Ohio's Union County recently on Land.com. The total size of all Union County farms, ranches, and rural real estate for sale was around 1,000 acres. Union County ranks 56th in Ohio for the combined amount of land currently advertised for sale. Of all locations in Union County with land for sale, Marysville had the most land for sale. From an economic perspective, manufacturing and related services are the main sectors in Union County. Union County is Ohio's 49th largest county (436 square miles). It's located in the Central Ohio region of the state.