Letter of introduction for Dwight B. Heard on the arrival of National Park Service Director Stephen T. Mather to Phoenix. Mather's visit includes trips to Roosevelt Dam and Tumacácori.

Letter from Carl Hayden to W. W. Bass asking his opinion on the proposed boundaries of the National Park. GC Natl Park written on the letter in blue pencil.

Letter from Carl Hayden to W. W. Bass asking his opinion on the proposed boundaries of the National Park. GC National Park written on the letter in red pencil.

Letter from Carl Hayden to Hugh E. Campbell with an enclosed outline map of the proposed boundaries of Grand Canyon National Park.

Letter from Carl Hayden to L. S. Williams about the potential to expand the park boundaries.