So I realized after looking closely at aerial photos of Indian Line at Claireville, that my assumptions about the bridges there were wrong. I had thought that the Indian Line bridge was washed out by Hurricane Hazel in October 1954 and replaced by the Bailey Bridge that I was so familiar with driving over in the 1970's. The aerial photos clearly show that although there was extensive flooding in 1954, the bridge at Indian Line was NOT washed out by Hurricane Hazel, and it was there until construction of the Claireville Dam in 1963/64. At that point, they built a detour road with the Bailey Bridge - see above, so the traffic could still travel around the dam construction. I also had not realized that it was almost 10 years after Hurricane Hazel before the dam was built. It was clear by the width of the bridge north of the dam, and the alignment of the road over the dam, that the original plan was to restore Indian Line back to that alignment and that the road would travel over the dam, and the Bailey Bridge would be removed as it was temporary. For some reason (probably changing their mind about traffic crossing the dam), the alignment was never put back to the dam road, and the 'temporary' Bailey Bridge remained in faithful service until 1983 when the 427 was extended. Almost 20 years that single lane Bailey Bridge was the main route up Indian Line. You can clearly see the Bailey Bridge in the photo above, although I have still never found any photos of it from the ground. It was my daily route in the late 1970's and I recall stopping at the traffic lights there that let traffic alternate on the single lane.
Here in 1983, you can see that the Bailey Bridge has been removed.