Alvord Lake Bridge

The Alvord Lake Bridge, located in Golden Gate Park, is the first reinforced concrete bridge built in the United States. Completed in eighteen eighty-nine, the structure is a single arch spanning twenty feet. Its designer, Ernest L. Ransome, utilized his own invention of square cold-twisted steel bars for reinforcement, embedding them longitudinally within the concrete to improve its strength. To give the bridge a natural appearance, Ransome used formliners to score and hammer the concrete surface so it resembled sandstone, and he added sculpted concrete stalactites to the underside of the arch to simulate a cave.