Benton MacKaye (/mæˈkaɪ/ mak-KYE; March 6, 1879 – December 11, 1975) was an American forester, planner and conservationist. He was born in Stamford, Connecticut; his father was actor and dramatist Steele MacKaye. After studying forestry at Harvard University (B.A., 1900; M.A. School of Forestry, 1905), Benton later taught there for several years. He joined a number of Federal bureaus and agencies, including the U.S. Forest Service, the Tennessee Valley Authority, and the U.S. Department of Labor; he was also a member of the Technical Alliance where he participated in the Energy Survey of North America.
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.