- Columbia County, Washington (data.census.gov)
Columbia County, Washington has 868.6 square miles of land area and is the 31st largest county in Washington by total area. Columbia County, Washington is bordered by Walla Walla County, Washington, Franklin County, Washington, Garfield County, Washington, Wallowa County, Oregon, Umatilla County, Oregon, and Whitman County, Washington.
- Columbia County — Thumbnail History (historylink.org)
Columbia County, in southeastern Washington, has a population of 4,064 (in 2000), making it one of the more sparsely populated of Washington’s 39 counties. At 868.8 square miles, it is the ninth-smallest county in the state.
- Columbia County, Washington (Wikipedia)
Columbia County is a county located in the U.S. state of Washington. As of the 2020 census, the population was 3,952, making it the second-least populous county in Washington. The county seat and largest city is Dayton. The county was created out of Walla Walla County on November 11, 1875, and is named after the Columbia River (which does not flow through the county). Columbia County is included in the Walla Walla, WA Metropolitan Statistical Area.
