Land for sale in Pennsylvania's Union County recently totaled almost $12 million and around 1,000 acres. Union County ranks 59th in the Independence State for the combined amount of land currently advertised for sale. Of all farms and rural real estate for sale in Union County, Lewisburg had the most land for sale. Government and state-level services are the main economic drivers in Union County. Union County is Pennsylvania's 64th largest county (317 square miles). It's located in the Alleghenies & Valleys Pennsylvania region of Pennsylvania.