The value of all farms, hunting land and other rural land and acreage for sale in Clay County recently was almost $900,000, representing a total of 73 acres of land for sale in Clay County. Clay County ranks 100th in the Land of Lincoln for the total number of acres of land currently advertised for sale. Of all locations in Clay County with farms, rural land, hunting land and other land for sale, Flora featured the most land for sale. Manufacturing and related services are the largest economic sectors in Clay County. Clay County is the 60th largest county (469 square miles) in Illinois. It's located in the Southern Illinois region of Illinois.