July 25, 2025
The AHC and Corridor Monitoring
by Corrie Monitte and Lucy Cantwell

I’m a corridor monitor from the Appalachian Trail Conservancy (ATC). I’m here to tell you about the work that your club and 30 other maintaining clubs do to preserve the 2,000-plus-mile footpath known as the AT.

Once a year, the Allentown Hiking Club monitors the boundaries of the AT “corridor” (the sliver of land on either side of AHC's 10.3-mile section of the trail). This is land owned by the National Park Service, and it extends a few hundred feet on either side of the trail.

A critical component of the stewardship of the AT maintaining clubs is corridor monitoring and boundary maintenance—keeping a close eye on the federal estate purchased to protect the Appalachian Trail. Corridor monitoring means walking along and examining the border between this NPS land and the adjacent lands (for example, privately owned lands, state game lands, municipalities) to assure that all boundary markers are in place and no encroachments have occurred. This involves leaving the AT treadway and bushwhacking over rocks and through dense vegetation to locate "monuments," i.e., the markers installed by the original surveyors to establish a line between NPS lands and that of neighboring landowners.

The Allentown Hiking Club monitors 35 tracts containing over 600 acres, which has 106 surveyor's monuments and about 15 miles of exterior boundary. This is divided into 7 sections and is monitored by women and men from our club who commit to individual segments of about 4-7 miles each. Encroachments, such as illegal dumping of waste, timber theft, rock piles, discarded machinery, hunting blinds, or evidence of incompatible uses such as ATVs are also documented. These discoveries are subsequently reported to the ATC and corrective action is taken, if needed.

During the monitoring we also post signage along the boundary lines, indicating which areas belong to the NPS, and address minor maintenance issues around the monuments. Volunteer monitors thus become the “eyes and ears” of state and federal landowning agencies. Monitoring helps assure the American public that its investment is being cared for and protected.

The monitoring process is not unlike a scavenger hunt, with instructions and GPS to assist you. If you are a person who loves an adventurous hike, this is it. Some of our long-time monitors, who have been performing this function for upwards of 20 years or more, are no longer able to commit to this duty. So we are looking for some new volunteers to help with this very important task!

Just like our little friend above, you can be a part of this action team! According to the ATC Volunteer Leadership Handbook, Corridor Monitors "are responsible for visiting and reporting on the condition of an assigned area of corridor land within a Trail club’s section.... Volunteers interested in monitoring may be quite different from those who like trail work—good monitors often enjoy orienteering, bushwhacking, and traveling in rugged terrain." If you think you might be interested in participating in corridor monitoring, please contact the AT Monitor Coordinators listed under "Contacts" in this newsletter.

We'll teach you how to collect the required information by pairing you with an experienced monitor assessing his/her section of the trail. The commitment on your part, after this simple training, is basically one day a year, scheduled by you at your convenience. Be adventurous! Volunteer and see what it's all about!

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To learn more about the Appalachian Trail Conservancy, and how it is working to protect and preserve the natural, historical, cultural, and recreational resource known as the AT, please visit the ATC website.