The correct answer to this open question is the following.
Hikers owe a debt of gratitude to Appalachian trail club members because these 31 Appalachian trail clubs and their members volunteered to maintain the trail and take care of the signals and markers for the hikers to have a good experience. This groups provided shelters to the millions of hikers that yearly travel along the 2,144 miles Appalachian National Scenic Trail, the longest footpath of the world.