Geology of the Yellowstone National Park; Part 2; Descriptive Geology, Petrography, and Paleontology - Hague A. Arnold; Innings J. P.; Weed W. H.; Walcott C. D.; Girty G. H.; Stanton T. W.; Knowlton F. H. (Monographs of the United States Geological Survey Vol. 32, Part 2)