A dozen years after forming the Appalachian Mountain Club in 1876, its members embarked on an ambitious mission to build a refuge for hikers of the rugged ridgeline of the Presidential Range in the White Mountains. Now, 125 years later, the AMC is celebrating the anniversary of the nation’s oldest mountain hut system with special hut hikes, educational programs and commemorative items, including posters, patches, pint glasses and clothing. Each hut is staffed with a crew that includes a naturalist. Stays include dinner and breakfast, at a cost averaging $98 for AMC members and $118 for nonmembers. Staff members discuss the ecosystem around the hut and talk about what they do to minimize the impact to the environment.