The value of all land for sale in Union County, Pennsylvania, recently was nearly $11 million, representing a combined 123 acres of land for sale in Union County. Union County ranks 62nd out of 67 counties in the Keystone State for the total number of acres of land currently advertised for sale. Of all locations in Union County with land and rural real estate for sale, Lewisburg had the most land for sale. From an economic perspective, government and state-level services contribute most to Union County's overall GDP. Union County is the 64th biggest county (317 square miles) in Pennsylvania. It's located in the Alleghenies & Valleys Pennsylvania region of the state.