The value of all farms and ranches for sale in Missouri's Warren County recently was almost $109 million, representing a combined 2,533 acres of land for sale in Warren County. Warren County ranks 25th out of 115 counties in the Show Me State for the total number of acres of land currently advertised for sale. Of all ranches, farms, hunting land and other rural land and acreage for sale in Warren County, Marthasville featured the most land for sale. Manufacturing and related services are the largest economic sectors in Warren County. Warren County is the 100th largest county (437 square miles) in Missouri. It's located in the Northeast Missouri region of the state.