The 553-acre (224 ha) Thomas Lake area in the northeastern corner of the city, bordered to the north by 132nd Street and east by Seattle Hill Road, was annexed in 2005 and added 2,200 residents to the city's population.

annexation of

Wikipedia contributors. (2024, January 16). Mill Creek, Washington. In Wikipedia, The Free Encyclopedia. Retrieved February 13, 2024, from https://en.wikipedia.org/w/index.php?title=Mill_Creek,_Washington&oldid=1196087295

History of Western State Hospital (dshs.wa.gov) Western State Hospital is located on the site of historic Fort Steilacoom, which served as a military post from 1849 to 1868 until the federal government abandoned it. The Washington territory purchased the fort with the intent of turning it into a hospital for people who suffered from mental illness. The hospital, then called the Insane Asylum of Washington Territory, opened in 1871 with 15 male and six female patients.

Mill Creek, Washington (Wikipedia) Mill Creek is a city in Snohomish County, Washington, United States. It is located between the cities of Everett and Lynnwood, approximately 20 miles (32 km) northeast of Seattle. The city has a population of 20,926 as of the 2020 census. The city lies along State Route 527 and North Creek, a tributary of the Sammamish River, on the east side of Interstate 5.