Thank you for the info. For a budding engineering student,this is terrific for me.
To answer Chalon Harper's comments, Koss Construction was the contractor, not engineer. The bridge was designed by Missouri State Highway Department. Chief Engineer For the Bridge was B. H. Piepmeier. The contractor would have bid on the design, and yes, they did work elsewhere in the state, but I doubt they had any say in the design. I did find some interesting information from the National Register Nomination for this bridge which is one of the longest nomination narratives I have ever seen and is VERY informative about the history of the bridge. You may wish to view it as well at http://www.dnr.missouri.gov/shpo/nps-nr/91000591.pdf
For interest, I attached a historic photo from that Nomination Form with this post, as well as one of the modern nomination photos that shows the bridge layout more clearly than the photos currently here.
The similarities seen to the bridges in Oregon may have to do with the architectural style that was used with this arch bridge. From the National Register Nomination:
The Y Bridge clearly fits a stylistic category, "Classical Moderne," a conservative form of Art Deco which came to the forefront during the depression era of the 1930s... a simplified and monumental modernistic neoclassicism. The Y Bridge, therefore, represents an early example of a style which would be so associated with the public works projects of the 1930s that it is sometimes referred to as PWA (Public Works Administration) Moderne, and which dignifies many courthouses and other public buildings constructed in the Ozarks. While Classical Moderne is associated with the PWA, its inception clearly precedes the PWA.
This is a genuine, beautiful, historic Y bridge: not a modern non-historic one such as seen in Zanesville, Ohio, which was demolished and replaced with a modern bridge that still has the Y shape but has destroyed all historic material.
It seems to me Koss Construction patterned some of their bridges off of Conde B. McCullough bridges with their open-spandrel arch. Also the elegance in them is reminiscent of Mr.McCullough's bridges.
All I can say is.......WOW!!!
Bridge enthusiasts,does this bridge type not remind you of a Conde B. McCullough (Oregon Bridge Engineer) bridge? When I first saw this it hit me it looks like a McCullough bridge.
I live in Zanesville, Ohio . The OFFICIAL Y-BRIDGE CITY. Ours is part of the Famous Zanes National Road built around 1900. Which is STILL used for public transportation.