Filtering by
- All Subjects: maps
- All Subjects: Mining
- All Subjects: Matthes, François Émile, 1874-1948
- All Subjects: Theodore Roosevelt Dam (Ariz.)
- All Subjects: Tillotson, Miner Raymond, 1886-1955
- All Subjects: World War I
- Creators: Hayden, Carl T.
- Creators: The Military engineer
Letter from Carl Hayden to George Otis Smith asking his advice regarding the mining of asbestos deposits in the Grand Canyon.
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 L. L. Ferrall on the favorable conditions for creating a national park and the prospect of the United States entering WW I.
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 Ed Hamilton informing him that Superintendent Tillotson will submit a report on the conditions of the road between Grand Canyon Village and Rowe's Well.
Letter from Carl T. Hayden to Alf Dickenson about mine locations within the park.
Letter from Carl T. Hayden to Louis C. Cramton about potential prosecution of people with mining claims within park boundaries.