Land for sale in Putnam County, Ohio, recently totaled around $3 million and 1,000 acres. Putnam County ranks 80th out of 88 counties in the state for the total acreage of land currently advertised for sale. Of all locations in Putnam County with ranches, farms, hunting land and other rural land and acreage for sale, Ottawa featured the most land for sale. Manufacturing and related services are the largest economic 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.