A total of around 1,000 acres were listed for sale in Mason County, Illinois, recently, representing a combined almost $6 million in Mason County farms, hunting land and other rural land and acreage for sale. Mason County ranks 90th in the state for the total acreage of land currently advertised for sale. Among cities in Mason County with farms, hunting land and other rural land and acreage for sale, Forest City had the most land for sale. Mason County is Illinois's 47th largest county (563 square miles). It's located in the Western Illinois region of Illinois.