The value of all land and rural real estate for sale in Washington's Columbia County recently was almost $8 million, representing a combined 3,417 acres of land for sale in Columbia County. Columbia County ranks 39th in Washington for the total acreage of land currently advertised for sale. Dayton featured the most land for sale. Columbia County has a large agricultural economy, with 308 farms recorded in the county during the latest U.S. Census. Farming activities in Columbia County generate annual revenues of $3 million, most of which is from crops. Columbia County is the 31st biggest county (873 square miles) in Washington. It's located in the Eastern Washington region of Washington.