The records include general correspondence, 1901-51, with an index, 1901-16; a collection of geologists' field notebooks, 1867-1939, consisting of notes, usually in diary form, rough sketches, maps, and diagrams made in the course of geologic investigations or in the examination of individual mines; summaries relating to stratigraphy compiled for the Committee on Geologic Names, 1894-1938; and records relating to the Arkansas bauxite program, 1942-46. There are also records of the Section of Areal Geology, consisting of correspondence relating to folios for the GEOLOGIC ATLAS OF THE UNITED STATES, 1907-20, and records relating to the Section of Western Areal Geology, 1912-16; records of the Mineral Resources Division, including correspondence relating to war activities, 1917-18, a general file, 1918-19, and fiscal records, 1887-88; general records of the Mineral Deposits Branch, 1910-52, relating to chromite depositis, 1941-45, potassium nitrate, 1916-18, potash, 1944-49, and other metals, 1942-46; records relating to western dolomite investigations, 1942-45; records of the Section of Geology of Iron and Aluminum Deposits, including staff correspondence, 1915-45; records of the Fuel Branch, consisting of correspondence concerning fuel development, 1943-48; and records of the Foreign Geology Branch, including a report file on strategic minerals in Brazil, 1941-46, and records concerning the Brazil mica and quartz programs, 1943-45. Also records of Arnold Hague, including a general file of letters, memorandums, and reports, 1881-86; letters received and sent, 1880-1916; records relating to proposed legislation for forest reserves, 1890-97; records concerning meteorology, 1885-87; manuscripts and reference material, 1883-1915; and publications relating chiefly to Yellowstone Park, 1869-1912.
