Gianella Bridge, Spanning Sacramento River at State Highway 32, Hamilton City, Glenn County, CA
Significance: The Gianella Bridge is the oldest remaining highway swing bridge in California. It is important in local history for its relation to events in local economic and agricultural development. It is the work of John B. Leonard, one of the most important early 20th century bridge engineers. It was listed on the National Register of Historic Places in 1982.
Survey number: HAER CA-44
Building/structure dates: 1908-1911 Initial Construction
Building/structure dates: 1937 Subsequent Work
Building/structure dates: 1954 Subsequent Work
National Register of Historic Places NRIS Number: 82004614