Letter from Joseph J. Cotter to Carl Hayden regarding the use of water power and summer homes in the proposed park boundaries.

Letter from Stephen T. Mather to Carl Hayden with markup of bill S 390 for the proposed National Park.

Letter from the Director of the National Park Service, Stephen T. Mather, to Jesse L. Boyce informing him that immediate action is being taken to remove the TNT from the Grand Canyon.

Letter from Stephen T. Mather to Carl Hayden regarding amendments to the national park bill including Mather's approval of the Secretary of the Interior granting railroads rights of way.

Letter from Joseph J. Cotter to Carl Hayden providing a rebuttal to W. W. Bass' objections to the Grand Canyon National Park Bill.

Letter from Stephen Mather to Carl T. Hayden regarding automobile regulations within Grand Canyon National Park.

Letter from Stephen T. Mather to Carl T. Hayden advocating for a reduction in automobile fees for the South Rim entrance.

Letter from Stephen T. Mather to Carl T. Hayden regarding a negative newspaper article about the National Park Service and Stephen Mather.

Letter from Stephen T. Mather to Carl T. Hayden thanking Hayden for his advice about visiting Arizona.

Letter from Carl Hayden to Stephen Mather regarding the sale of Bass properties.