The overall value of land and rural real estate for sale in Madison County, Idaho, recently on Land.com was approximately $42 million. This represents 3,000 acres of farms and ranches for sale in Madison County. Madison County ranks 42nd out of 44 counties in the Gem State for the combined amount of land currently advertised for sale. Among cities in Madison County with ranches, farms, hunting land and other rural land and acreage for sale, Rexburg had the most land for sale. Madison County is the 42nd biggest county (473 square miles) in Idaho. It's located in the Eastern Idaho region of Idaho.