Taken sometime in the 1970s after it was damaged by a flash flood.
Photo taken by Grover Brinkman
BH Photo #125990
After looking at the enlarged photo of the piers on the Stone Church Road Bridge, I now see my original assumption was incorrect. The piers are poured concrete, not riveted steel like I thought. So, it looks like the entire bridge (including the piers) was replaced. However, I still stand by my claim that the Stone Church Road Bridge and the mystery bridge are one in the same.
The terrain in the background of photo three of four of the Stone Church Road Bridge bears a striking resemblance to the terrain shown in the background of the "Mystery Bridge" photo. The years also coincide since the "Mystery Bridge" was damaged by a flood in the early 70s and the Stone Church Road Bridge was rehabilitated in 1971. Lastly, the superstructure of the Stone Church Road bridge does not appear to be circa 1925 construction. However, its piers do resemble those commonly built during that period. It is reasonable to assume that after the flood damaged the original bridge, the trusses and deck were removed and replaced with more modern steel I-beams. However, the superstructure we now see was simply constructed on the original piers. I would say the "Mystery Bridge" shown in the 1970s photo is that of the original Stone Church Road Bridge.