Folded title: The Grand Canyon of the Colorado. "This map was compiled from 1972 aerial photography and field surveyed by Bradford Washburn, assisted by Barbara P. Washburn, Harry R. Feldman, and Wendell Mason. Relief by Tibor G. Toth, research and compilation by Thomas L. Gray, contours by Norbert and Walter Vasques, all National Geographic staff." Relief shown by shading, contours, spot heights, and hachures. "Transverse Mercator projection." "Supplement to National Geographic, July 1978, page 35A, vol. 154, no. 1." Computer mosaic of the Grand Canyon, location map, map of Landsat imagery area, geologic cross section of the Grand Canyon, 3 relief diagrs., and text on verso.