The 1915 American Grand Prize and Vanderbilt Cup were both held on a temporary circuit in the grounds of the Panama-Pacific Exposition close to San Francisco’s Golden Gate Bridge. It was a grand setting with palm trees lining the course that ran past the sites impressive pavilions. Unusually for a road course much of the surface was made of wooden planks which cannot have helped when it rained during the GP. Dario Resta’s Peugeot won both events. The area which had held a race in 1909 later became the city’s Marina District.