- King County, Washington (Wikipedia)
King County is located in the U.S. state of Washington. The population was 2,269,675 in the 2020 census, making it the most populous county in Washington, and the 13th-most populous in the United States. The county seat is Seattle, also the state’s most populous city.
- Pierce County, Washington (Wikipedia)
Pierce County is a county in the U.S. state of Washington. As of the 2020 census, the population was 921,130, up from 795,225 in 2010, making it the second-most populous county in Washington, behind King County, and the 60th-most populous in the United States. The county seat and largest city is Tacoma. Formed out of Thurston County on December 22, 1852, by the legislature of Oregon Territory, it was named for U.S. President Franklin Pierce. Pierce County is in the Seattle metropolitan area (formally the Seattle-Tacoma-Bellevue, WA, metropolitan statistical area).
- Milton is a city in King County and Pierce County counties in the U.S. state of Washington. The population was 8,697 at the time of the 2020 census. Milton borders the larger but newer town of Edgewood.