Treasure Island and Yerba Buena Island
Treasure Island and Yerba Buena Island has been known by many names including Seabird Island, Wood Island and Goat Island. Yerba Buena Island history includes a considerable amount of controversy over its use and ownership. Washington ordered its occupation in 1868 to keep Yerba Buena Island out of the hands of the Central Pacific Railroad. Treasure Island, a man made island, has been used as an international airport, site of the 1939–40 World’s Fair: Golden Gate International Exposition and as a military base. The Museum of The City of San Francisco has an article and links to additional World’s Fair information.
Clipper Cove—between Treasure Island and Yerba Buena Island was named for the airplanes that took off from the cove before the island was taken over by the Navy at the beginning of WWII. Clipper Cove and Treasure Island were recently host to the SF International Dragon Boat Festival.
In this 1935 historical aerial photo of the San Francisco, Oakland Bay Bridge construction you can see that Treasure Island does not yet exist!
The Bay Bridge
The San Francisco-Oakland Bay Bridge, an 8.5 mile long combination suspension / cantilever structure, passes through Yerba Buena Island and connects San Francisco with Contra Costa and Alameda Counties.
When it was first constructed the Bay Bridge was the most expensive man-made structure ever built, the longest steel high-level bridge in the world and the 58 foot Yerba Buena Tunnel was the tallest bore in the world.
The part of the Bay Bridge that connects San Francisco and Yerba Buena Island is really two suspension bridges. A monolithic concrete pier in the middle supports one end of each to the two bridges.
The Bay Bridge foundations extend to 200 and 242 feet below water — 100 feet into the mud. The deeper pier required more concrete than the Empire State Building and is bigger than the largest of the Pyramids in Egypt. Statistics and history of the Bay Bridge are on this Caltrans™ site.
A controversial design for replacing the east span of the San Francisco – Oakland Bay Bridge was accepted and construction begun, halted then started again. Part of the two tier span was damaged in the October 1989 Loma Prieta earthquake. Construction of the new East span is expected to be completed by the fall of 2013. State-owned bridges will have a toll increase to $4 to pay for cost overruns associated with delays as the governor and legislature debated design details.