I don't know if you are anywhere near Bartow county, since they are reference books, the library probably won't do interlibrary loan (but you can always try)- there are books by Bill Scaife in the library. There is a book on Allatoona Pass for sale at the Etowah Valley Historical society (at least there was) but they probably have their own copy you can peruse. There is a pic on the wall of the old courthouse (where the Etowah Valley Historical society is located) of the railroad (more like the destruction around it) at the Etowah river I don't remember if there is a specific date with the pic though.