Harbor Island is an artificial island in the mouth of Seattle, Washington's, Duwamish River where it empties into Elliott Bay. Built by the Puget Sound Bridge and Dredging Company, Harbor Island was completed in 1909 and was then the largest artificial island in the world, at 350 acres. Harbor Island was made from 24 million yd³ of earth removed in the Jackson and Dearborn Street regrades and dredged from the bed of the Duwamish River. Filling in the vast tide flats south of downtown Seattle, the dredging also created the area now occupied by Union Station, King Street Station, Seattle's sports stadiums, and much of the city's industrial base.

Since 1912, Harbor Island has been used for commercial and industrial activities, including secondary lead smelting, shipbuilding and repair, bulk petroleum storage, metal fabrication, and containerized cargo shipping. Warehouses, laboratories, and other buildings are located on the island. This aerial photograph of Harbor Island, taken on July 20, 1964, is looking south, along the Duwamish River. The SW Spokane Street Bridge connects the island to both banks of the river.

John Fraser Vallentyne (1928-2002) was an aerial photographer for The Boeing Co. and a staff photographer for the Seattle Post-Intelligencer in the 1950s-1960s.

Caption information source: "Harbor Island, at the time the world's largest artificial island, is completed in 1909," David Wilma, http://www.historylink.org/File/3631
Caption information source: "John F. Vallentyne, photographer, dies at 74," by D. Parvaz, Seattle Post-Intelligencer, July 1, 2002