Stump Creek Bridge
Photo taken by Chris Gonnerman in May 2012
License: Creative Commons Attribution-Share-Alike (CC BY-SA)
Trusses were still being built in Iowa as the crossings of small creeks, and, in the case of my hometown of Muscatine, major river crossings, up until the mid 70s or so.
This might be one where the NBI has a rehab date rather than build date. I can't picture this being built new in 1967.