Letter from A. F. Potter to John H. Page referring his request to build a railway to the District Forester at Albuquerque, New Mexico.

Letter from A. F. Potter to Carl T. Hayden describing John H. Page's request to build a railway for the Canyon Copper Company as "impractical."

Letter from George Otis Smith to Carl Hayden regarding mining rights in the Grand Canyon.

Letter from Carl Hayden to George Otis Smith asking his advice regarding the mining of asbestos deposits in the Grand Canyon.

Letter from George Otis Smith, U.S. Geological Survey to Carl Hayden regarding asbestos mining prospects in the Grand Canyon.

Letter from Carl T. Hayden to Louis C. Cramton about potential prosecution of people with mining claims within park boundaries.

Letter from Carl T. Hayden to Alf Dickenson about mine locations within the park.