The overall value of farms and ranches for sale in Idaho's Madison County recently on Land.com was approximately $34 million. This represents 3,000 acres of farms, ranches, hunting land and other land for sale in Madison County. Madison County ranks 42nd out of 44 counties in the Gem State for the total acreage of land currently advertised for sale. Rexburg featured the most land for sale. Madison County is the 42nd largest county (473 square miles) in Idaho. It's located in the Eastern Idaho region of the state.