Parks Bar Bridge, Spanning Yuba River at State Highway 20, Smartville, Yuba County, CA

Significance: The Parks Bar Bridge is significant under Criterion C, as a distinctive example of an unusual method of construction. It is one of the earliest and largest remaining examples of the Thomas System of pre-cast, reinforced concrete, three-hinged arch bridges. This early 20th-century design and method of bridge construction was patented by William M. Thomas during his association with W.S. Post in their Los Angeles engineering firm of Thomas and Post. This is the sixth of approximately seventeen Thomas System bridges built in California, and one of only three remaining. The bridge was determined eligible for the National Register of Historic Places in 1986.

Survey number: HAER CA-132

Building/structure dates: 1913 Initial Construction

Building/structure dates: 1924 Subsequent Work

bridges concrete arch bridges open spandrel arches three hinged arches transportation civil engineering smartville parks bar bridge parks bar bridge yuba yuba river highway state highway yuba county california leslie crook barry lee gill historic american engineering record noble brothers david parks w s post william m thomas ultra high resolution high resolution library of congress national register of historic places

1969 - 1980

Library of Congress

http://www.loc.gov/

No known restrictions on images made by the U.S. Government; images copied from other sources may be restricted. http://www.loc.gov/rr/print/res/114_habs.html