The best account of western coal mining is Andrews.
David A. Wolff, Industrializing the Rockies: Growth, Competition, and Turmoil in the Coalfields of Colorado and Wyoming, 1868-1914 (Boulder: Univ. of Colorado Press, 2003), 5-6, 21-22.
An exception was the Rocky Mountain Coal and Iron Company, which supplied the Central Pacific.
Wolff, Industrializing the Rockies, 33.
Gardner and Flores, Forgotten Frontier, 26.
Gould to Silas U. U. Clark, Feb. 29, 1876, HM 62486, Gould to Silas Clark, Aug. 3, 1878, HM 62500, Railroadiana (Western USA), pt. 2, 1869-1901, Huntington Library.
"A Plea for Free Labor," in Bromley, Chinese Massacre, 90.
Storti, Incident at Bitter Creek, 59-66.
Gardner and Flores, Forgotten Frontier, 27-29, 33-39.
Clark to Bromley, Oct. 28, 1885, Orr to Callaway, Oct. 30, 1885, UP, RG 2361, box 21, Labor Disputes, Oct. 1885.