The Pacific-Union Club is a social club located at 1000 California Street in San Francisco , California , at the top of Nob Hill . It was founded in 1889 as a merger of two earlier clubs : the Pacific Club ( founded 1852 ) and the Union Club ( founded 1854 ) . The clubhouse was built as the home for the silver magnate James Clair Flood . The former Flood Mansion is located in the Nob Hill neighborhood . It was designed by Willis Polk . It is considered the first brownstone constructed west of the Mississippi River . Along with the Fairmont Hotel across the street , it was the only structure in the area to survive the San Francisco earthquake and fire of 1906
San Francisco earthquake and fire of 1906
1906 San Francisco earthquake
Pacific-Union Club