This is, I think, an abandoned Pratt Pony Truss type bridge with what remains of a timber wooden deck - with large holes in places. Pratt Truss bridges are characterized by having a horizontal top chord - the beam on the top which allows for longer spans but tend to not be as rigid due to the lack of cross braces. This one had six vertical braces, and two sets of thin tensionable rod diagonal braces nearer each end. The Pony refers to the height of the bridge - any taller and it would be a Pratt Through Truss bridge - because you travel through it with the sides taller than you. I did not cross it. And to get from one side to another took a long detour. Photographed April 2009.
If anyone has a better description of the bridge type let me know. I wonder also what the eyelets - three on each top chord and one on each end post, were for. Perhaps there was more to this bridge originally.