The value of farmsand rural real estate for sale in Jefferson County recently on Land.com was approximately $22 million. This represents nearly 1,000 acres of land and rural real estate for sale in Jefferson County. Jefferson County ranks 62nd out of 72 counties in the Badger State for the combined amount of land currently advertised for sale. Watertown featured the most land for sale. From an economic perspective, manufacturing and related services are the main sectors in Jefferson County. Jefferson County is Wisconsin's 61st largest county (582 square miles). It's located in the Southwest Wisconsin region of the state.