Sixth Annual Report of the United States Geological Survey of the Territories, embracing portions of Montana, Idaho, Wyoming, and Utah, being a report of progress of the explorations for the year 1872
Conducted under the authority of the Secretary of the Interior. List of annual reports, with contents of each, and author and subject index may be found in "Catalogue and index of the publications of the Hayden, King, Powell, and Wheeler surveys" by L.F. Schmeckebier. 1904. (U.S. Geological Survey. Bulletin no. 222).