others (with the exception of Greenbank and Bayview) are all Census-designated places, and all but Bayview have their own post offices and ZIP codes. Economy Whidbey Island is divided economically into two different regions: the northern end of the island (encompassing Oak Harbor and Whidbey Island Naval Air Station), and the remainder of the island (encompassing Coupeville, Greenbank, Freeland, Langley, Clinton and the smaller communities in-between). The economy of the northern end of Whidbey Island is strongly influenced by the presence of Whidbey Island Naval Air Station near Oak Harbor (N.A.S. Whidbey). N.A.S. Whidbey is Oak Harbor's largest employer; thus, Oak Harbor has a predominantly service-based economy and several national chain stores have been attracted to the Oak Harbor area. The economy of Whidbey Island south of Oak Harbor relies heavily on tourism, small-scale agriculture, and the arts. Tourism is especially important for both Whidbey and Camano Islands. On Whidbey, tourists find a wide range of amenities in the towns of Oak Harbor, Coupeville, Freeland and Langley. Coupeville's Penn Cove Mussel Farm exports large quantities of its highly renowned Penn Cove Mussels. This aquaculture facility, along with a number of small farms, reflects the rural agricultural nature of most of central Whidbey Island. Many of these small farms host farm stands onsite, where customers may buy produce, flowers, meat, eggs and other locally raised products directly from the farmers. Whidbey is home to numerous working artists, writers, and performers. These include many well-known painters, sculptors, glass artists, wood workers, metal workers, mixed media artists, photographers, authors, poets, actors, and musicians. In addition to being a haven for artists, the southern end of Whidbey Island also serves as a minor bedroom community for the nearby cities of Everett, where the Boeing Everett Factory is located, and Seattle. Commuters to and from those areas use the Washington State Ferries system's run between Clinton and Mukilteo. Geography Whidbey Island is often claimed to be the longest island in the continental United States (or another similar claim), but according to the Seattle Times it cannot be correctly considered so. The island has several bays, including on its east side Oak Harbor with the town of Oak Harbor at its base, and Penn Cove with the towns of Coupeville and San de Fuca on its south and north shores respectively. Whidbey Island has four lakes that are part of its interior hydrology: Cranberry Lake (inside