Issaquah is a city in King County, Washington, United States. The population was 30,434 at the 2010 census.
According to the Washington State Office of Financial Management, Issaquah ranked 6th of 279 eligible incorporated communities in population growth between 2000 and 2005. Forbes.com ranked Issaquah the 2nd fastest-growing suburb in the state, and the 89th in the nation.
According to the United States Census Bureau, the city has a total area of 11.40 square miles (29.53 km2), of which, 11.38 square miles (29.47 km2) is land and 0.02 square miles (0.05 km2) is water
Issaquah is surrounded on three sides by the Issaquah Alps: Cougar Mountain on the west, Squak Mountain to the south, and Tiger Mountain to the east. To the north of Issaquah is Lake Sammamish. Cougar and Squak Mountains are home to sizable neighborhoods, 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. Geologists have noted the chemical and geological content of these three mountains to be much different than that of the Cascade Range, simply 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.