Second Annual Report of the United States Geological Survey of the Territories, embracing Wyoming
Pages 220-255 of the Report of the Commissioner of the General Land Office for the year 1868. Reprinted in 1873 under title: First, Second, and Third Annual Reports of the United States Geological Survey of the Territories for the years 1867, 1868, and 1869. 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).