The overall value of land for sale in Washington's Columbia County recently on Land.com was nearly $8 million. This represents around 4,000 acres of land and rural real estate for sale in Columbia County. Columbia County ranks 39th in Washington for the total acreage of land currently advertised for sale. Among cities in Columbia County with land and rural real estate for sale, Dayton had the most land for sale. Agriculture and farming drives the Columbia County economy, with 308 farms recorded in the county during the U.S. Census in 2012. Farming activities in Columbia County generate annual revenues of $3 million, most of which is from crops. Columbia County is the 31st largest county (873 square miles) in Washington. It's located in the Eastern Washington region of Washington.