Near Smartsville in Nevada County, California — The American West (Pacific Coastal)
The Yuba River Bridge at Parks Bar
1913 - 1994
William Thomas established himself as a leader in early reinforced concrete bridge design by developing the "Thomas System." This system consisted of precast construction, three-hinge arches and open spandrels. Each arch had three flexible connections: one on each base and one joining the arch halves in the middle. Open spandrels (triangular spaces between the arches and the deek) added to the beauty of the bridge.
Over time, the river bed lowered and eroded the bridge's base. Undermining of the footings hastened replacement of this impressive early example of the "Thomas System."
This bridge was determined eligible for the National Register of Historic Places in 1984
Topics. This historical marker is listed in this topic list: Bridges & Viaducts
Location. 39° 13.17′ N, 121° 20.005′ W. Marker is near Smartsville, California, in Nevada County. Marker is on Timbuctoo Road south of California Highway 20. Timbuctoo Road is the access road to the river. Touch for map. Marker is in this post office area: Smartsville CA 95977, United States of America. Touch for directions.
Other nearby markers. At least 8 other markers are within 4 miles of this marker, measured as the crow flies. Timbuctoo (approx. 0.9 miles away); Sucker Flat (approx. 1.9 miles away); Church of the Immaculate Conception (approx. 2.1 miles away); Smartsville Grocery (approx. 2.1 miles away); Smartville / Smartsville (approx. 2.1 miles away); Edward James McGanney (approx. 2.1 miles away); Mooney Flat Hotel (approx. 3.2 miles away); Hammon Grove (approx. 3.6 miles away). Touch for a list and map of all markers in Smartsville.
Also see . . .
1. Historic American Buildings Survey, Engineering Record. Information regarding the bridge along with numerous photos of its construction and completion. (Submitted on April 8, 2012.)
2. William Thomas. A short biography of William Thomas published in Western Edition Notables of the West, Vol. I, Page 778. Published in 1913. (Submitted on April 8, 2012.)
Credits. This page was last revised on June 16, 2016. It was originally submitted on April 8, 2012, by Syd Whittle of El Dorado Hills, California. This page has been viewed 864 times since then and 34 times this year. Photos: 1, 2, 3, 4, 5. submitted on April 8, 2012, by Syd Whittle of El Dorado Hills, California.