No accurate maps have been made of the whole region covered by this report. A very excellent aerial survey has been made of the Navajo Reservation, but this does not extend more than eight miles east of Wijiji, and does not show quite all of the Chaco canyon. No profile or cross-section of Chaco Canyon exists, except for the maps made by the National Parks Service. As these cover only about three-quarters of a mile, they are not of great assistance in matters concerned with the grade of the stream bed. They are a valuable start, however, and they have been drawn on freely for any information which they contain
