Land for sale in Garfield County recently totaled approximately $3 million and approximately 1,000 acres. Garfield County ranks 38th in the state for the total acreage of land currently advertised for sale. Pomeroy featured the most land for sale. From an economic perspective, government and state-level services contribute most to Garfield County's overall GDP. Garfield County is the 33rd largest county (718 square miles) in Washington. It's located in the Eastern Washington region of Washington.