The combined value of farms, ranches, hunting land and other land for sale in Putnam County, Ohio, recently on Land.com was $3 million. This represents almost 1,000 acres of land and rural real estate for sale in Putnam County. Putnam County ranks 80th in the Buckeye State for the total acreage of land currently advertised for sale. Of all locations in Putnam County with land and rural real estate for sale, Ottawa had the most land for sale. From an economic perspective, manufacturing and related services are the main sectors in Putnam County. Putnam County is Ohio's 36th largest county (484 square miles). It's located in the Northwest Ohio region of Ohio.