The Eastern Wilderness Act of 1975 expanded protections of the original Wilderness Act (1964) to a variety of wilderness areas in the Eastern United States. Of these, only the James River Face Wilderness in Virginia contained a portion of the Appalachian Trail, but over the coming decades a growing list of wilderness areas in the Appalachian Mountains included more and more of the Trail.

The Wilderness Act of 1964 provided federal protection for large tracts of public land deemed to be at risk. The original land acquisition for the National Wilderness Preservation System included just over 9 million acres of land, largely in the western U.S., and today includes almost 110 million acres. Written by Wilderness Society member Howard Zahniser, the Act requires that those areas added to the System be kept as free of human imprint as possible and that its wilderness character be preserved.

This sign outside Monson warns Appalachian Trail hikers that they are about to enter the dreaded 'Wilderness,' a 90-mile stretch that offers few human contacts and almost no amenities

"Pie lady," Sydney Pratt, gets a lot of customers from hikers on the Appalachian Trail, Monson, Maine

Appalachian Trail sign in Damascus, VA

Benton MacKaye, who was first to propose the Appalachian Trail, poses for a photo along the Trail near Newfound Gap in the Great Smoky Mountains National Park on September 24, 1933.

A modern-day aerial view of Monson, Maine

Inside of the slate company mill operation with several workers. Monson slate is considered to be a fine quality because of the black color.