Originally determined eligible in the Caltrans 1985 Historic Concrete Arch Bridges in California Thematic Resources study; its continued eligibility was confirmed in the 2004 Caltrans Historic Bridge Inventory update: Concrete Arch Bridges.
The Tim Bell Road Bridge (38C0073) is a reinforced-concrete, open-spandrel, fixed, round-arch bridge that features an unusual use of both concrete and timber. The railings, spandrel posts, stringers and all members other than the ribs are timber. The bridge carries a rural road that in 1915 did not warrant a major building expense. The county surveyor's solution for providing an inexpensive permanent structure included using a poured reinforced-concrete arch and timber for the remaining structure. This confluence of reinforced concrete and timber stinger technologies is unique in California. The deck system was replaced in 1979, including the timber stringers, caps, and some timber posts.