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.

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

Letter from F. R. Goodman to Carl Hayden expressing Coconino County's interest in handing over Bright Angel Trail to the government provided a sufficient amount of money is appropriated to build a road from Maine to the Grand Canyon.

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 Ralph H. Cameron to Carl Hayden thanking him for forwarding Senate Bill No. 390 with the report of March 31st, 1918, and expressing interest in their upcoming meeting in Washington.

Letter from Ralph H. Cameron to Carl Hayden requesting a delay on the introduction of the Grand Canyon bill until he can meet with himself and Senator Ashurst in Washington.

Letter from Ralph H. Cameron asking to speak to Carl Hayden concerning a matter relevant to the bill granting National Park status to the Grand Canyon.

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.

Letter from F. R. Goodman to Carl T. Hayden asking for clarification about the agreement to construct an approach road to the park