Treasure Island, San Francisco

Treasure Island, San Francisco
Name	Treasure Island
Location	San Francisco Bay, California
Coordinates	37, 49, 27, N...
Area km2	1.53
Population	Approximately 2,500
Population as of	2020

Treasure Island, San Francisco. An artificial island located in San Francisco Bay, it was constructed for the 1939–1940 Golden Gate International Exposition on shoals north of Yerba Buena Island. Following the exposition, the site was converted into a United States Navy station, playing a significant role during World War II and the Cold War. Today, it is a mixed-use neighborhood undergoing major redevelopment, known for its panoramic views of the San Francisco skyline, the Bay Bridge, and the Berkeley Hills.

History

The island was created from over 25 million cubic yards of dredged material from the bay, a project led by the WPA in conjunction with the construction of the San Francisco–Oakland Bay Bridge. It served as the site for the 1939–1940 Golden Gate International Exposition, a world's fair celebrating the completion of the Golden Gate Bridge and the Bay Bridge. After the fair, the United States Navy acquired the island, establishing Naval Station Treasure Island and later Naval Auxiliary Air Facility Treasure Island, which became a major processing center for sailors during World War II, including those deploying to the Pacific Theater. During the Cold War, it housed the Treasure Island Naval Station and was a key site for the U.S. Atomic Energy Commission's Naval Radiological Defense Laboratory. The base was selected for closure under the Base Realignment and Closure process in the 1990s, with ownership transferring to the City and County of San Francisco in 1997.

Geography and environment

The island is situated between San Francisco and Oakland, directly north of the natural Yerba Buena Island and connected to it by a causeway. Its geology consists entirely of bay mud and sand, making it vulnerable to liquefaction during seismic events, a significant concern given its location near the San Andreas Fault and Hayward Fault Zone. Environmental assessments have identified contamination from its military past, including traces of radium and other chemicals, leading to ongoing cleanup efforts supervised by the California Department of Toxic Substances Control and the United States Environmental Protection Agency. The shoreline provides habitat for local bird species and offers some of the most iconic views in the San Francisco Bay Area.

Development and infrastructure

Following the Navy's departure, the San Francisco Board of Supervisors approved a large-scale redevelopment plan managed by the Treasure Island Development Authority. The master plan, designed by architects like Skidmore, Owings & Merrill, envisions up to 8,000 residential units, commercial space, and new parks. Critical infrastructure projects include a new ferry terminal, a sea wall for sea level rise protection, and utility upgrades. The island's notable existing structures include the historic Administration Building from the 1939 exposition and the former USS Panay memorial. Development has been coordinated with agencies such as the San Francisco Public Utilities Commission and the Bay Conservation and Development Commission.

Demographics

As of the 2020 United States Census, the island's population was approximately 2,500 residents. The community is housed primarily in former Navy barracks and family housing, with a diverse mix of incomes. A significant portion of residents are participants in the San Francisco Mayor's Office of Housing and Community Development affordable housing programs. The population is expected to grow substantially upon completion of the redevelopment, which mandates a high percentage of below-market-rate units as part of the community benefits agreement with the city.

Culture and events

The island hosts several annual events that draw visitors from across the Bay Area, including the popular Treasure Island Music Festival, though its future location is uncertain due to development. The Treasure Island Museum, located in the former Administration Building, chronicles the island's history from the exposition through its naval service. Independent film productions and television shows, such as episodes of MythBusters, have frequently used the island's unique landscapes and empty hangars as filming locations. Its open spaces also regularly host events like the San Francisco Chronicle's "Championship" and various cultural fairs.

Transportation

Primary vehicular access is via the San Francisco–Oakland Bay Bridge from the Interstate 80 causeway that links to Yerba Buena Island. Public transportation includes the San Francisco Municipal Railway's 25-Treasure Island bus line, which connects to the Transbay Terminal in downtown San Francisco. A seasonal ferry service operated by the San Francisco Bay Ferry runs between the island and the San Francisco Ferry Building. The redevelopment plan includes a new multimodal transit center designed to prioritize pedestrian and bicycle access, with planned improvements to connect to the Bay Trail.

Category:Islands of San Francisco Bay Category:Artificial islands in the United States Category:Neighborhoods in San Francisco