I have been a trail monitor for the Appalachian Trail for probably over 15 years. A monitor, more precisely a corridor monitor acts as the eyes and ears for the AT. A monitor surveys the property and must like to bushwhack in the woods. Good map and compass work is needed in order to follow the property lines to make sure outsiders are not disturbing the National Park Service land.
Typical impacts might be littering, ATV use, hunting and other things you would not want on your property. Sometimes we find someone building a road or a building on these public lands.
If interested in checking this out, let me know.