In the mid seventies, the Appalachian Trail still had a lot of road walking.
The Cumberland Valley road walk has been rerouted since 1975.
To read an excellent account on the re-route, check out Korostof, N., Yanher, T., & Johns, T. (1991). In International Linear Parks Conference. Parkways, Greenways, Riverways: A Partnership for Beauty and Progress. Appalachian State University.
found at this link.
or this one
Yahner, T. G., Korostoff, N., Johnson, T. P., Battaglia, A. M., & Jones, D. R. (1995). Cultural landscapes and landscape ecology in contemporary greenway planning, design and management: a case study. Landscape and urban planning, 33(1-3), 295-316.
found here.