Land for sale in Roger Mills County, Oklahoma, recently totaled approximately $7 million and around 3,000 acres. Roger Mills County ranks 70th out of 77 counties in the Sooner State for the total number of acres of land currently advertised for sale. Among cities in Roger Mills County with farms, ranches, hunting land and other land for sale, Cheyenne featured the most land for sale. Roger Mills County is Oklahoma's 13th largest county (1,146 square miles). It's located in the Great Plains Country Oklahoma region of Oklahoma.