Of 44 counties in the Gem State, Jefferson County is 28th in terms of its size (1,105 square miles). Jefferson County is in Eastern Idaho. The total value of approximately 1,000 acres of riverfront land and property recently listed for sale in Jefferson County, Idaho, was about $2 million. Browse all waterfront property for sale in Jefferson 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 Jefferson County is house.