McHenry County is in Northern Illinois. Of the 102 counties in the Prairie State, 391,091-acre McHenry County ranks 36th by size. Recent listings of residential land for sale in Illinois's McHenry County totals roughly 1,000 acres and a combined market value of roughly $127 million. By overall acreage, homesite is the most common type of land for sale in McHenry County. The average price of residential acreage for sale in McHenry County was $892,829. Browse all residential land and rural property for sale in Illinois to find residential land and properties that suit your lifestyle needs, from existing residential homes and estates to land ready for future residential-property development.