Each is an updated file. Most of these you can download and then save to kindle on your phone for use when hiking.
These are useful links.
I’ve also added them to Useful links
Also, a huge list of links: https://www.lengthytravel.com/appalachian-trail-resources/?fbclid=IwAR3KigPSWGVM4GMJYnSpukbsOLoWuPSlnxTDFyVlc00Ez6SCoPjktT5K2Ks