Columbia County on the map of Washington 2025. Cities, roads, borders and directions in Columbia County of Washington.

Columbia County is located in the southeastern part of the state of Washington. This special county is named after the Columbia River. The county seat of Columbia County is Dayton. The county's area is about 869 square miles. Established in 1875, today Columbia County is home to 4 thousand residents. This map shows the borders of Columbia County as well as neighboring counties, including major highways and natural objecsts as of 2025. Zoom in or out of the map using the plus/minus panel. Move the center of this map by dragging it. Also check out the satellite map of Columbia County.