Issaquah ( ) is a city in King County, Washington, United States. The population was 40,051 at the 2020 census. 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 Wholesale Corporation. Issaquah is included in the Seattle metropolitan area.
thumb|Sunset Way in downtown Issaquah
History
thumb|left|Coal miners' homes in Issaquah, 1913
"Issaquah" is an anglicization of the Southern Lushootseed placename /sqʷáxʷ/, 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; seven attackers were indicted, but they were later acquitted or charges were dropped.
The city was officially incorporated by the Washington State legislature on April 29, 1892.
Geography
Issaquah is located east-southeast of Seattle at the south end of Lake Sammamish. Its neighboring cities are Bellevue to the west and Sammamish to the north. Issaquah resides within the Mountains to Sound Greenway.
According to the United States Census Bureau, the city has a total area of , of which are land and are water.
Issaquah is surrounded on three sides by what are known locally as the Issaquah Alps: Cougar Mountain on the west, Squak Mountain to the south, and Tiger Mountain to the southeast. To the north of Issaquah is Lake Sammamish. Cougar and Squak Mountains are home to sizable neighborhoods on their lower slopes, though the bulk of all three mountains are preserved in public ownership as Squak Mountain State Park, Cougar Mountain Regional Wildland Park, West Tiger Mountain NRCA, and Tiger Mountain State Forest.<nowiki> Geologists have noted the chemical and geological content of these three mountains to be much different from that of the </nowiki>Cascade Range, because they are not volcanic in origin, while the entire Cascade Range is postulated to have formed from volcanic action. They believe that these three mountains are the remains of a much older mountain range long since eroded by earthquakes, volcanic action, and shifting plates.
Climate
Issaquah has a warm-summer Mediterranean climate (Köppen: Csb) with chilly, extremely wet winters and warm, moderately humid summers. Although there is no dry season in Issaquah, winters are many times wetter than the summers. Rainfall amounts are extremely similar to the neighboring city of Sammamish, which is 0.06 inches wetter overall, with the same summer rain amounts.
Economy
Warehouse retailer Costco has been headquartered in Issaquah since 1996. Other major Issaquah employers include Microsoft, Siemens Medical Solutions' Ultrasound Group, Overtime Technologies, Boehm's Candies, and Darigold. Apparel wholesaler SanMar is also headquartered in the city. A large gravel quarry, operated by Lakeside Industries, is located on immediately north of downtown Issaquah. It is planned to be redeveloped into a residential and commercial neighborhood over a 30-year period as quarry operations are phased out.