Benton MacKaye (məkī´), 1879–1975, American forester and regional planner, b. Stamford, Conn., grad. Harvard (B.A., 1900; M.A. School of Forestry, 1905); son of Steele MacKaye. He was a research forester of the U.S. Forest Service; he planned and helped in the construction of the Appalachian Trail (1921) and served on the regional planning staff of the Tennessee Valley Authority (1934–36) and on the staff of the Rural Electrification Administration (1942–45). MacKaye's philosophy of regional planning is given in The New Exploration (1928).