The two bridges appear to be of the same builder, likely one that was regional to those states as I haven't seen any like it around here.
Robert,
Interesting! Now I am really curious about the one James saw, and where its located which would help determine whether it was the design of a government or a builder. The design strikes me as unusual for a couple reasons. First, of course, the use of hub guard lattice railing mounted on top of the girder. Second, this "girder and floorbeam system" type bridge really isn't a "plate girder" in the traditional sense because its girders are not built-up from plate but are instead rolled beams.
Nathan:
Good catch about that stringer. Here is a nearly identical bridge.
http://bridgehunter.com/ks/marshall/irish-creek/
I actually did not think much of the Kansas example when I discovered it - just thought it was a "low-budget" modern bridge with some recycled parts. Now I am glad that I took a couple pictures of it.
Nice to see some photos of this rare bridge. Photo #25 shows a different but also interesting plate girder bridge with hub guard lattice railing. I am curious if you have additional photos of that bridge and would consider giving that bridge its own page on Bridgehunter. I would be curious to know where its located.
Nathan, Anthony:
A page for the Nebraska example has been uploaded. It is located in Grand Island, Hall Co., Nebraska.
http://bridgehunter.com/ne/hall/unnamed-creek/