Former Superintendent Edmund B. Rogers and Park Naturalist David de L. Condon gave me access to the records of the Park. Their interest in advancing the knowledge of Yellowstone has been keen and constant.

My Yellowstone Park ranger-colleagues also served as sources of information and occasional critics. It is probable that each of them will be able to identify an element of his own thought or expression in the narrative. As my campfire lectures evolved into a unified monograph, guidance was received from professional historians. They have been more critical than the rangers but not less kind.

At the State College of Washington, Dr. Herman J. Deutsch and Dr. Claudius O. Johnson made the college’s Northwest Collection available. They also joined their colleagues, Dr. W. B. Thorson and Dr. C. M. Brewster, in making many fine and comprehensive criticisms, which combined to strengthen the narrative. Several of my colleagues at Idaho State College gave direction and increased purpose to the discussion of conservation and wild life principles. They are Dr. Ray J. Davis, Albert V. S. Pulling, and DuWayne Goodwin. Dr. Carl W. McIntosh, president of the college, has extended many courtesies. Professor Wallace E. Garets edited the manuscript.

Former Yellowstone National Park Naturalist, Dr. C. Max Bauer, gave encouragement from the inception of the study and reviewed the final draft. Other National Park officials from whom wise council and valuable suggestions were received include Dr. Carl P. Russell, former National Park Supervisor of Interpretation, and Dr. Alvin P. Stauffer, Chief of Research and Survey. The collaboration of J. Neilson Barry was invaluable in the exposition of the discovery phase in the chapter on John Colter. J. Fred Smith, Delbert G. Taylor, and Mr. and Mrs. George Marler have also given material support to this effort.

The illustrations are principally the work of William S. Chapman, North District Ranger.

The support of Yellowstone Park Superintendent Lemuel A. Garrison and Chief Park Naturalist Robert N. McIntyre in bringing forth this Third Edition under the auspices of The Yellowstone Library and Museum Association is indeed appreciated.

Lastly, gratitude is due my wife, Bessy N. Beal, and our son, David, and his wife, Jean, for the typing of the manuscript and for the rendering of much additional service to this enterprise. MERRILL D. BEAL