The route of the Lower Trail follows what was once the Juniata Canal. Later the canal was filled in and the route became part of the Pennsylvania Railroad. A history of the Juniata Canal describes how it was part of a canal system crossing Pennsylvania. Inclined railways were used to carry the canal boats across mountains to connect on canal system to another.
The Allegheny Portage Railway was used to carry the canal boats across the mountain. The National Historic Site for this railway is located about 15 miles west of the western end of the Lower Trail. This is a very interesting site with a restored section of the railway which carried canal boats across the mountain.
There are several historic markers like this showing the history of the canal and railroad.