A total of 1,000 acres were listed for sale in Mercer County, Pennsylvania, recently, representing a total value of almost $28 million in Mercer County farms, rural land, hunting land and other land for sale. Mercer County ranks 47th out of 67 counties in the Keystone State for the combined amount of land currently advertised for sale. Among cities in Mercer County with farms, hunting land and other rural land and acreage for sale, Greenville had the most land for sale. Mercer County is the 33rd largest county (682 square miles) in Pennsylvania. It's located in the Great Lakes & Wilds Pennsylvania region of the state.