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 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.

Letter from Carl Hayden to Stephen Mather requesting that congress pay W. W. Bass the sum of twenty-five thousand dollars for his properties.

Letter from Stephen Mather, National Park Service to Carl Hayden on payment to W. W. Bass.

Letter from Stephen Mather to Carl Hayden regarding the sale of Bass properties to the Santa Fe Railroad Company.

Geological examination of the park canyonland, with description of the rocks, water sculping process, volcanic cones and outflows, and land erosion. This edition is Volume 2, 1977 reprint, of the author's 1882 monograph. Includes 12 color maps, 10 color views and is number 280/1500.