MacKaye helped pioneer the idea of land preservation for recreation and conservation purposes, and was a strong advocate of balancing human needs and those of nature; he coined the term "Geotechnics" to describe this philosophy. In addition to writing the first argument against urban sprawl, MacKaye also authored two books, "The New Exploration: A Philosophy of Regional Planning" and "Expedition Nine: A Return to a Region". Thirteen of his essays were published in the collection "From Geography to Geotechnics". A co-founder of The Wilderness Society, he is best known as the originator of the Appalachian Trail (AT), an idea he presented in his 1921 article titled "An Appalachian Trail: A Project in Regional Planning." The Benton MacKaye Trail, some portions of which coincide with the Appalachian Trail, is named after him.