Members of a Potomac Appalachian Trail Club (PATC) day hiking group at the summit of Mount Katahdin in 1939. Of the 37 individuals in the image, 22 signed the photograph on the back. Almost half of the group is female, showing the high degree of participation in these expeditions by female members of the Club. It is also worth noting that the now iconic sign on the Katahdin summit was not there in 1939.

A group of day hikers at an Appalachian Trail shelter in the Great Smoky Mountains National Park (1959).

A small group of volunteer trail maintainers on the Appalachian Trail in the Great Smoky Mountains National Park, May 19, 1947. The Appalachian Trail is unique among America's long distance hiking trails in that it is maintained almost exclusively by groups of volunteers from the many trail clubs that take care of the Trail along its more than 2,000 mile course.