Mill Creek is a city in Snohomish County, Washington, United States. It is located approximately 20 miles north-northeast of downtown Seattle and is part of the Seattle metropolitan area. The 2010 census population as of 18,244. Mill Creek was originally a planned community built around a golf course and country club as its centerpiece. Mill Creek was officially incorporated on August 30, 1983. The city has rapidly grown with large number of families and jobs and now contains a mixed-use, city-sponsored complex called Mill Creek Town Center. Before the turn of the 21st century much of Mill Creek was woods, but recently many apartment complexes have been built all along Bothell- Everett Highway and some other roads throughout the city. This has attributed to a much larger High school, going from a 2A school at its inception (1994) to a 4A school at around 2,000 students. It contains a large part of the green belt in the south-eastern part of town.