Letter from Field Assistant Horace M. Albright to Carl Hayden requesting letters to be drafted in regards to the grazing of sheep and cattle on national park lands. Bankhead and Henderson are singled out as not keeping to their permit restrictions.

Letter from Horace M. Albright to Carl Hayden requesting a formal submission from Coconino County concerning the Bright Angel Trail.

This plan was undertaken by the Arizona Department of Transportation Multimodal Planning Division Aeronautics Group to evaluate and recommend a terminal area layout to meet anticipated terminal area demands.

Cooperative National Park Resources Studies Unit for University of Arizona, effects on Glen Canyon Dam releases on Grand Canyon River trips, a technical report, vol. no. 16.