Found the answer to my old question. This bridge was moved here in 1952, which would account for the mystery pier below the structure, which would have been from the previous bridge.
As I've looked more at the photos I posted last week of the bridge (in particular http://bridgehunter.com/photos/32/21/322166-L.jpg), I am scratching my head as to why there is a pier on the northwest end of the bridge. That pier is on the left side of the photo and has since partially collapsed. It doesn't appear to have borne any structural load. Was there another bridge here before this one?
Pure speculation, but the portal bracing indicates a possible George E. King structure. Of course, portal bracing rarely gives a definitive identification of the builder, but it can provide some clues.
Thanks for putting a name to the detail. Armed with that information, I found another publication that describes the detail, and notably includes a drawing on the following page.
http://books.google.com/books?id=GcM5AAAAMAAJ&dq=%22Star%20S...
Waddell calls it a "star strut", and seems to not like ones made from only two angles like the ones on this bridge.
In the glossary in the 1916 edition of _Bridge_Engineering_ he says, "A strut formed of either two or four angles placed back to back. The two-angle form is not a satisfactory type, as it fails to develop as high an ultimate strength as might properly be anticipated."
I haven't seen many star struts - and haven't ever seen any others built with lattice tying the angle stock together.
James and I discussed this vertical detail and its not like anything either of us has seen before.
The vertical member in photo 8 has been built up in an unusual way. Anyone know of others like it?
This bridge vertical and one on the Barker Bridge in Williamson County, Tx
George King did build down there so it makes sense. The Barker Bridge did have a dis-configuring makeover to it's portals that hinders a possible connection, but this feature is so unusual I feel that parental lineage is very likely.
Photos "Borrowed" from James Baughn and Garry Taylor for comparison usage.