Sullivan County is in Northeast Mountains Pennsylvania. Of the 67 counties in the Keystone State, Sullivan County ranks 50th in terms of size (452 square miles). There is roughly 1,000 acres of residential land for sale in Sullivan County, Pennsylvania, based on recent Land Network data. The combined market value of farms and rural land for sale here is roughly $3 million. The average price of residential acreage for sale in Sullivan County was $510,466. Browse all residential land and rural property for sale in Pennsylvania to find residential land and properties that suit your lifestyle needs, from existing residential homes and estates to land ready for future residential-property development.