A sign marking the Appalachian Trail at a road crossing near Bobblet's Gap in Central Virginia, August 4, 2016.

As the Appalachian Trail was being constructed in the 1920s and 1930s, the various trail clubs at first used their own methods for blazing the Trail's route. However, it soon became clear that a common approach was needed to help hikers know how to stay on the new trail's path. The executive committee of the Appalachian Trail Conservancy agreed at its 1929 meeting to an official insignia for the trail blazes utilizing the now familiar AT logo.

Trail clubs experimented with several different means of marking the Trail, with the ATC ultimately settling on a galvanized metal marker like the one seen here. Ultimately, the metal markers were replaced by the now familiar (and easier to maintain) white blaze. This particular marker was photographed on the Trail north of Troutville, Virginia in 2016.

Appalachian Trail Sign, Plum Orchard Gap, Georgia, just south of the North Carolina/Georgia border.

Marking the Appalachian Trail in the Great Smoky Mountains National Park. Albert Roth is adding one of the original AT blaze signs to the trail route just south of Clingman's Dome.