A combined 3,000 acres were listed for sale in Union County, Iowa, recently; the overall value of all Union County farms, ranches, and rural real estate for sale was nearly $25 million. Union County ranks 70th out of 99 counties in the Cyclone State for the combined amount of land currently advertised for sale. Creston had the most land for sale. From an economic perspective, manufacturing and related services are the main sectors in Union County. Union County is Iowa's 91st largest county (425 square miles). It's located in the Western Iowa region of the state.