The arch with welded sections built up from rolled plate steel cut in the arch form with welded seams, and the Modernist simple pipe railings and rounded concrete end posts are the bridge's most distinctive features. The Smith River Bridge is an important example of a bridge from just after World War II. Welding was not widely used in bridge construction in California until the mid- to late-1950s. The arch is tied back and secured to the abutments with heavy welded shoes. Both the welding and the arch design led to the use of less steel than might have been used in a truss structure. The welded arch also enhanced the bridge's aesthetic design. Welding afforded cleaner lines and a smooth appearance to the steel components and exhibit the abstract qualities indicative of post-war Modernism.