On back: "SAN FRANCISCO-OAKLAND BAY BRIDGE; Walter G. Swanson; 500 Sansome St. - GA rfield 1415. San Francisco. File 900.11 B-12/BD. Aerial view of Pier E-3 of the East Bay Crossing with erection of fender and pedestals in progress. This is the world's deepest pier - extending to a maximum depth of 242 feet below sea level."