Page 105 - Historical Study of Yerba Buena Island, Treasure Island and Their Buildings

Chapter 2 Treasure Island

2.1 Introduction

The history of Treasure Island is relatively short and easily divided into the following two eras:

• Construction through the Golden Gate International Exposition, 1936-1940
• Military use and occupation, 1940-Present (1995)

Construction of Treasure Island was started on February 11, 1936, by the Army Corps of
Engineers. Eighteen and one-half months later, on August 24, 1937, construction of the island
was completed on time and under budget. The building of the Exposition structures and the
landscape preparation continued for the next eighteen months. On February 18, 1939, the
Golden Gate International Exposition opened on schedule. The Exposition was built to celebrate
the completion of the Golden Gate and San Francisco-Oakland Bay Bridges. It was also an
attempt to draw the United States (US) citizens out of "the Depression" of the 1930s by a
positive display of unity among nations. The building of the island would also give the City of
San Francisco an international airport after the Exposition closed. The future was supposed to
look bright. But, war clouds had already gathered on the horizon. War had already broken out in
Europe, and Japan was well into its conquest of Korea, China, and Indochina. In fact, the
Swastika flag of Nazi Germany and the Rising Sun Flag of Japan were two of the many flags
waving at the Exposition's ground-breaking ceremony.

The reality of war was not to be denied. In the five months that followed the Exposition's
September 29, 1940 closing, the Navy was granted a lease to take possession of Treasure Island
" ... until the passing of this present national emergency." The City of San Francisco exchanged
the lease of Treasure Island to the Navy for the Navy's assistance in its obtaining bayshore
property in the City of San Bruno for an airport. San Francisco realized that Treasure Island
would become inadequate for use as an international airport. Advances in aircraft technology
demonstrated the growing need for a much larger parcel of land that would allow future
expansion. The San Francisco-Oakland Bay Bridge was becoming busier and planners could see
potential safety risks because of the closeness of flight paths to the bridge and its traffic. The
Navy, on the other hand, liked the placement of Treasure Island and preferred to remain there.
So, the deal was struck to the satisfaction of both sides.

2.2 Treasure Island Construction through the Golden Gate
International Exposition, 1936-1940

Built to celebrate the completion of the great engineering marvels of the Golden Gate Bridge and
San Francisco-Oakland Bay Bridge, Treasure Island was itself a magnificent 20 th Century
engineering achievement. Constructed by the Army Corps of Engineers in the incredibly short
time of 18½ months, the island has a perimeter seawall comprised of 287,000 tons of rock that
supports 29,665,152 cubic yards of sand and gravel fill which was dredged from the bottom of
San Francisco Bay. Once the seawall was raised to a height of 13 feet above sea level, the fill, a
mixture of sand, gravel, and baywater, was poured into the newly created cavity via dredge lines.
The baywater was separated from the sand and gravel and pumped from the developing island
through several wells. Once the cavity was filled, desalinization of the fill was accomplished by

September 1, 1995 Historical Study ofYerba Buena Island, 2-1
Treasure Island, and their Buildings