Island County Transportation Roads and Highways Major roadways on Whidbey Island include State Route 20 in the northern half of the island and State Route 525 in the southern half of the island. Several provincial routes also exist, mostly to provide coastal access. Whidbey Island is connected to the mainland by State Route 20, which extends westward from U.S. Interstate 5 near Mount Vernon in Skagit County. Camano Island is connected to the mainland by State Route 532, which extends westward from U.S. Interstate 5 near Stanwood in Skagit County. Provincial roads extend from State Route 532 once the land-sea bridge is crossed. Washington State Ferries maintains a water highway system to and from Island County via two routes. The Mukilteo-Clinton route (south Whidbey Island) and the Port Townsend-Keystone route (north Whidbey Island).  Air Transportation There are three airfields in Island County (excluding the Whidbey Island Naval Air Station). They are Oak Harbor Airport, Whidbey Air Park and Camano Air Park. Oak Harbor Airport is served by Harbor Airlines, with daily flights to the San Juan Islands and Seattle (Sea-Tac). The other fields accommodate private aircraft only. Port and Rail Service Though Island County has several marinas, there are no facilities large enough to accommodate large ship transportation. As for barge service, the U.S. Navy (North Whidbey) has one slip that handles aviation fuel. There are no railroad facilities in Island County. || ALHN Island County || ALHN Washington ||