A combined around 1,000 acres were listed for sale in Mason County recently; the overall value of all Mason County land for sale was around $4 million. Mason County ranks 85th in the state for the combined amount of land currently advertised for sale. Among cities in Mason County with land for sale, Chandlerville 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 the state.