The combined value of farms, rural land, hunting land and other land for sale in Illinois's Mason County recently on Land.com was $5 million. This represents almost 1,000 acres of farms and rural real estate for sale in Mason County. Mason County ranks 97th in the state for the total acreage of land currently advertised for sale. Of all locations in Mason County with farms, rural land, hunting land and other land for sale, Forest City featured the most land for sale. Mason County is the 47th biggest county (563 square miles) in Illinois. It's located in the Western Illinois region of the state.