Issaquah ( ISS-ə-kwah) is a city in King County, Washington, United States. The population was 30,434 at the 2010 census and an estimated 39,509 in 2019. Located in a valley and bisected by Interstate 90, the city is bordered by the Sammamish Plateau to the north and the "Issaquah Alps" to the south. It is home to the headquarters of the multinational retail company Costco.
"Issaquah" is an anglicized word for a local Native American name, meaning either "the sound of birds", "snake", or "little stream". "Squak Valley", an older name for the area, also derives from this same Native American name.
In September 1885, the then-unincorporated area was the scene of an attack on Chinese laborers who had come to pick hops from local fields. Three of the laborers died from gunshot wounds, and none of the attackers were convicted of any wrongdoing.
The city was officially incorporated on April 29, 1892. Initially a small mining town, the city has changed noticeably both in its appearance and economic focus. Issaquah was originally developed to service the mining industry (on the two nearby mountains that now lend their names to the Cougar/Squak Corridor Park), and began as the town of "Gilman".