A total of 3,000 acres were listed for sale in Madison County, Idaho, recently; the combined value of all Madison County ranches, farms, hunting land and other rural land and acreage for sale was approximately $43 million. Madison County ranks 42nd in the Gem State for the combined amount of land currently advertised for sale. Of all locations in Madison County with land and rural real estate for sale, Rexburg had 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 Idaho.