Of 67 counties in the Independence State, Sullivan County ranks 50th by size (452 square miles). Sullivan County is in Northeast Mountains Pennsylvania. Recent Land Network data shows roughly 1,000 acres of lakefront homes and property for sale in Pennsylvania's Sullivan County, which is valued at a combined $659,900. Browse all waterfront property for sale in Sullivan County on the Land Network to find the marina, lakefront and other recreational property that meets your needs, from waterside land perfect as a retirement investment to existing residential waterfront land and property for hunting, fishing and other outdoor-recreation pursuits! The most common type of land for sale by combined acreage in Sullivan County is residential property.