The James C. Flood Mansion is a historic mansion at 1000 California Street, atop Nob Hill in San Francisco, California, USA. Now home of the Pacific-Union Club, it was built in 1886 as the townhouse for James C. Flood, a 19th-century silver baron. It was the first brownstone building west of the Mississippi River, and the only mansion on Nob Hill to structurally survive the 1906 San Francisco earthquake and fire. It was declared a National Historic Landmark in 1966.