Thurston County
Thurston County is situated at the southern end of Puget Sound. As of the 2020 census, its population was 294,793. The county seat and largest city is Olympia, the state capital.
It has a total area of 774 square miles (2,000 km2), of which 722 square miles (1,870 km2) is land and 52 square miles (130 km2) (6.7%) is water.
Thurston County was created out of Lewis County by the government of Oregon Territory on January 12, 1852. At that time, it covered all of the Puget Sound region and the Olympic Peninsula. On December 22 of the same year, Pierce, King, Island, and Jefferson counties were split off from Thurston County. It is named after Samuel R. Thurston, the Oregon Territory’s first delegate to Congress.