 Two of the five refineries operating in Washington are located near the town.One is owned and operated by Marathon Petroleum (opened in 1955, it was originally built and owned by Shell Oil and later operated by Andeavor [formerly Tesoro]), operating as the Marathon Anacortes Refinery, the other is owned and operated by Shell Puget Sound Refinery Company (opening in 1957, and originally built and owned by Texaco).Refining remains the area's largest industry, but the economic base now includes yacht construction/shipbuilding, tourism, and residential services for the nearby Whidbey Island Naval Air Station.