The overall value of farms and ranches for sale in Oregon's Gilliam County recently on Land.com was $20 million. This represents around 100,000 acres of ranches, farms, hunting land and other rural land and acreage for sale in Gilliam County. Gilliam County ranks 35th in the state for the total acreage of land currently advertised for sale. Of all farms, ranches, hunting land and other land for sale in Gilliam County, Arlington had the most land for sale. Gilliam County is Oregon's 25th biggest county (1,222 square miles). It's located in the Central Oregon region of Oregon.