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

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

Letter from Gifford Pinchot to John H. Page denying his request to build a railway on the rim of the Grand Canyon for the Canyon Copper Company.

Letter from Harold Greene to Carl Hayden regarding the proposed boundaries for the national park bill.

Letter from L. S. Williams to Carl Hayden stating there should be no objection to Saginaw and Manistee Lumber Company having their timber contract extended as it is greatly favored.

Letter from L. S. Williams to Carl Hayden suggesting a boundary amendment to the national park bill.