Thompson, Erwin N., "The First Fortifications, 1853–1863", The Rock A History of Alcatraz Island 1847—1972, Ocean View Publishing Company, Carmel, California, 2014 (accessed 28 June 2015).
archive.org
Cullum, George W., "1836, William H. Warner", Biographical Register of the Officers and Graduates of the United States Military Academy (Volume I), James Miller Publisher, New York, New York, 1 January 1879, p. 498.
Cullum, George W., "Robert S. Williamson", Biographical Register of the Officers and Graduates of the United States Military Academy (Volume II), James Miller Publisher, New York, New York, 1 January 1879, p. 209.
Bancroft, Herbert Howe, The Works of Herbert Howe Bancroft, (Volume XXX), History of Oregon: 1848–1888, The History Company Publishers, San Francisco, California, 1888, pp. 503–506.
Bach, Melva "Captain William H. Warner"Archived 2014-01-11 at the Wayback Machine, History of the Fremont National Forest, Fremont National Forest, United States Forest Service, United States Department of Agriculture, Bend, Oregon, 1990, p. 12.
Tinker, Joan Cockcroft, Introduction to "Excerpts from Last Diary", University of Rochester Library Bulletin (Volume XVII, Number 1), Department of Rare Books, Special Collections and Preservation, University of Rochester, Rochester, New York, Autumn 1962.
Bach, Melva "Captain William H. Warner"Archived 2014-01-11 at the Wayback Machine, History of the Fremont National Forest, Fremont National Forest, United States Forest Service, United States Department of Agriculture, Bend, Oregon, 1990, p. 12.