The combined value of land and rural real estate for sale in Putnam County recently on Land.com was around $200,000. This represents almost 1,000 acres of farms, hunting land and other rural land and acreage for sale in Putnam County. Putnam County ranks 97th in Illinois for the total acreage of land currently advertised for sale. Of all farms and rural real estate for sale in Putnam County, Putnam had the most land for sale. Putnam County is the 102nd largest county (172 square miles) in Illinois. It's located in the Western Illinois region of Illinois.