The value of all farms, ranches, and rural real estate for sale in Union County, Ohio, recently was around $150 million, representing a combined 923 acres of land for sale in Union County. Union County ranks 46th in the Buckeye State for the total acreage of land currently advertised for sale. Of all locations in Union County with farms, ranches, hunting land and other 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 the 49th biggest county (436 square miles) in Ohio. It's located in the Central Ohio region of Ohio.