The above illustration is a detail from a 1939 booklet issued for the Golden Gate International Exposition held on Treasure Island. Man-made Treasure Island was originally designed to be San Francisco’s new airport, and it briefly served in that capacity throughout the run of the Fair, and shortly thereafter as America prepared to enter World War II. A Pan Am Clipper is shown just to the right of Yerba Buena Island, where the new San Francisco-Oakland Bay Bridge passes through. The Clippers were seaplanes, and they docked in the port harbor north of Treasure Island.
Passenger air travel was then in its infancy, and it was soon determined that Treasure Island would not provide runways of a sufficient length for safe landing for non-amphibious aircraft. Also, Treasure Island provided an unobstructed view of the Golden Gate, and people were seriously worried about enemy submarine attacks. Since there had been a naval station on the natural island of Yerba Buena since 1898, it was perfectly logical for the United States Navy to extend its operations to Treasure Island, which was now connected to Yerba Buena via a vehicular exit from the bridge.
This map shows an extremely condensed view of the peninsula lying to the south of San Francisco. The upper left-hand corner of this illustration depicts a man parachuting down toward the San Francisco Municipal Airport, which has, of course, been greatly expanded, and still serves as San Francisco’s airport today.