Members of the Roanoke Appalachian Trail Club on Potts Mountain in Central Virginia during the fall of 1939. Day hikes like this one were a central activity of the AT Clubs for many decades.

A trail maintainer along the Appalachian Trail in 1932. The caption on the reverse of this photograph reads: "Homeward bound, with her pack and pruning shears after a day's work on the Appalachian Trail." Trail volunteers like this young woman were, and remain, essential to the building and maintaining of the Appalachian Trail.

Members of one of the Potomac Appalachian Trail Club (PATC) Shenandoah National Park trail crews creating water diversions on one of the many trails in the Park. Members of Appalachian Trail maintaining clubs devote hundreds of thousands of volunteer hours each year to the maintenance of the AT and its associated side trails.

Leaving the bus on a PATC trip to Smoke Hole, West Virginia, April 19, 1936. PATC hiking trips during this era were often organized with bus service for members.

Members of an Appalachian Trail maintenance crew from the Philadelphia Trail Club, March 23-24, 1935, near Little Gap, PA. The crew of 12 spent the weekend clearing scrub oak and other underbrush from the route of the Trail and blazed the new route they had created.

A member of the Philadelphia Trail Club clipping vegetation along the Appalachian Trail, March 23, 1935, on the Little Gap, PA section of the Trail. Club members "cut scrub oak and cleared nearly half a mile through the thickest growth," and later, "paint[ed] blazes all the way through to meet the blazes in from Smith Gap," according to a report of the trail work weekend. This work weekend was one of many that the Philadelphia Trail Club utilized to build their short section of the Trail in 1935.

Photograph of the Appalachian Trial between Thunderhead Mountain and Derrick Knob in the Great Smoky Mountains National Park. The photographer was Commodore (Cliff) Clifton Dunn and the photograph was taken in 1965.

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.

The Black Outdoors is a rapidly expanding organization that promotes hiker diversity.

Rulette Mapp is the founder and CEO of Outdoor Afro, an organization that focuses on encouraging men and women of color to experience and feel comfortable with outdoor activiteis such as hiking, biking, and camping.