San Lorenzo River Bridge (36C0085) is a double-hinged, steel deck arch truss bridge with a steel open-lattice arch, timber road deck, and short, timber-stringer approach spans. It is a subtype of metal arches that uses a truss design with an arch form. It is a deck style bridge supported by webbed triangular members with a curved bottom chord, as well as spandrel columns and lateral beams. This type was more difficult to fabricate and construct than standard through trusses of the early-twentieth century, but was desired for its aesthetic value. It is one of four remaining bridges of its type in California, three of which are eligible for the National Register. The other bridges include: 12 0038, 17C0006, and 57C0416.