The value of all farms, ranches, hunting land and other land for sale in Darke County, Ohio, recently was $17 million, representing a total of 405 acres of land for sale in Darke County. Darke County ranks 62nd in the Buckeye State for the total acreage of land currently advertised for sale. Of all farms, ranches, and rural real estate for sale in Darke County, Greenville had the most land for sale. Manufacturing and related services are the largest economic sectors in Darke County. Darke County is the 13th largest county (599 square miles) in Ohio. It's located in the Southwest Ohio region of the state.