I visited this bridge today and photographed it. (Photo below.) It actually has a picnic table at the end, so it looks like the Corps is allowing pedestrian use, but the bridge isn't being maintained and is rusting badly. Do we know when it was built? Judging by the style and the rivets (machine made and not molded), my guess would be the 1940s, but it's hard to tell. There's also clearly a support left on the opposite shore, so I'm guessing a Parker Through Truss completed the bridge at one time.
Melissa,
The details on this bridge seem to point to a likely late 1910’s-early 1920’s build date; my guess would be 1925 or earlier. Most of the rust looks to be minor surface rust (at least looking at the photo); it looks to be in good condition overall. Thanks for posting the pic; it’s a beauty!