I don’t have much to add to these four photos of the lock(s?) at Ardenheim. Ardenheim is just east of Huntingdon where the Raystown branch of the Juniata River joins with the main branch of the river.
The shot from summer is dated June 1971.
These are all dated April 1969. It almost looks like two locks. This one is not nearly as deep as the second one.
I would say that these two shots are of the same lock.
That’s all I got. The oldest topo map of this area was from 1922 and there is nothing on the web. If you know more, leave a comment.