Clark County, Washington

45°46′N 122°29′W / 45.77°N 122.48°W / 45.77; -122.48

Clark County
County
Clark County Courthouse
Location within the U.S. state of Washington
Washington's location within the U.S.
Coordinates: 45°46′N 122°29′W / 45.77°N 122.48°W / 45.77; -122.48
Country	United States
State	Washington
Founded	August 20, 1845 as Vancouver District
Named for	William Clark on September 3, 1849
Seat	Vancouver
Largest city	Vancouver
Area
• Total	656 sq mi (1,700 km2)
• Land	629 sq mi (1,630 km2)
• Water	27 sq mi (70 km2)  4.1%
Population  (2020)
• Total	503,311
• Estimate  (2022)	516,779
• Density	770/sq mi (300/km2)
Time zone	UTC−8 (Pacific)
• Summer (DST)	UTC−7 (PDT)
Congressional district	3rd
Website	clark.wa.gov

Clark County is the southernmost county in the U.S. state of Washington. As of the 2020 census, the population was 503,311,^[1] making it Washington's fifth-most populous county. Its county seat and largest city is Vancouver.^[2] It was the first county in Washington, first named Vancouver County in 1845 before being renamed for William Clark of the Lewis and Clark Expedition in 1849. It was created by the Provisional Government of Oregon in Oregon Country on August 20, 1845, and at that time covered the entire present-day state.^[3] Clark County is the third-most-populous county in the Portland-Vancouver-Hillsboro Metropolitan Statistical Area, and is across the Columbia River from Portland, Oregon.