The value of all ranches, farms, hunting land and other rural land and acreage for sale in Gilliam County, Oregon, recently was almost $20 million, representing a total of 8,707 acres of land for sale in Gilliam County. Gilliam County ranks 34th out of 36 counties in the Beaver State for the combined amount of land currently advertised for sale. Of all farms and ranches for sale in Gilliam County, Arlington had the most land for sale. Gilliam County is the 25th biggest county (1,222 square miles) in Oregon. It's located in the Central Oregon region of the state.