Of 10 counties in the state, Sullivan County is eighth in terms of its size (552 square miles). Sullivan County is in Central New Hampshire. There is 1,000 acres of riverfront land and property for sale in Sullivan County, New Hampshire, based on recent Land Network data. The combined market value of farms, hunting land and other rural land and acreage for sale here is about $500,000. 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.