Thurston County
Also known as Thurston County, Washington, Thurston County, WA
county in the state of Washington, United States
Key facts
- Country
- United States
- State
- Washington
- Founded
- January 12, 1852
- Named after
- Samuel Thurston
- Seat
- Olympia
- Largest city
- Lacey
- County manager
- Leonard Hernandez
- Total
- 774 sq mi (2,000 km )
- Land
- 722 sq mi (1,870 km )
- Water
- 52 sq mi (130 km ) 6.7%
- Estimate 2025
- 304,261
- Density
- 408/sq mi (158/km )
- Time zone
- UTC−8 ( Pacific )
~30 min read
Article
Thurston County is a county located in the U.S. state of Washington. As of the 2020 census, its population was 294,793. The county seat is Olympia, the state capital.
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. Today, the county includes the southernmost part of the South Puget Sound and areas south along the I-5 corridor.