In the 1850s, Irish immigrants began to settle in the Oak Harbor area, followed by Dutch immigrants in the 1890s. The town of Oak Harbor was officially incorporated on May 14, 1915. In July 1920, the “Oak Harbor Fire” destroyed much of the town. The town struggled through the Great Depression (1929-1939) until 1941 when the Navy arrived to build an air base. Suddenly Oak Harbor, a quiet farming community of some 650 inhabitants, was transformed into a boomtown as thousands of construction workers and Naval personnel arrived in the area. The number of active duty military personnel in Island County, excluding dependents, stays relatively constant, at about 6,000 to 7,000.
Whidey Island's and Island County's largest city.