Land for sale in Roger Mills County recently totaled almost $7 million and 2,000 acres. Roger Mills County ranks 69th out of 77 counties in the Sooner State for the total acreage of land currently advertised for sale. Of all farms, ranches, and rural real estate for sale in Roger Mills County, 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.