Of 102 counties in the Inland Empire, Jefferson County ranks 41st by size (583 square miles). Jefferson County is in Southern Illinois. Illinois's Jefferson County includes almost 1,000 acres of lakefront property for sale based on recent Land Network data. The combined market value of farms and rural land for sale here was nearly $300,000. 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 residential property.