Ah yes, I remember now.
First bridge I recall on this site was one peeled log with a handrail held up by a smaller log angling down to center of span from each end of bridge. As that was long ago I could easily be misremembering where it was.
Second bridge was built by AMC's paid seasonal pro crew on the abutments you see in the photo. It was a pony truss bridge made of extruded fiberglass members produced by ET Techtonics. Like all bridges it can be washed away in a flood, which happened in April 2011 during the Spring snowmelt, I seem to recall there was an ice jam plus heavy rains, but am not certain of those details. It was a strong well-built bridge. Too bad the designers did not think to make the abutments higher than they are. Since the brook drains the east side of Kinsman Ridge from Kinsman Pond Trail clockwise around to Hi-Cannon Trail including Kinsman Pond and Lonesome Lake... if there is ever another bridge there, I am sure the abutments will be much higher.