W. H. Mills to CPH, June 30, 1892, CPH Papers, ser. 1, r. 51.
CPH to Mills, Jan. 9, 1892, Jan. 11, 1892, CPH Papers, ser. 1, r. 50.
Mahl, Memoirs, Southern Pacific Co., F-1, Mahl Papers.
Mahl, Memoirs, Southern Pacific Co., F-1, Mahl Papers.
Stuart Daggett, Chapters on the History of the Southern Pacific (New York: A. M. Kelley, 1966, orig. ed. 1922), 136-38.
Mahl, Memoirs: P.I. Co., G18, Mahl Papers.