Without the acquisition by the Oberlin College Archives of Professor George Allen's field notebook and his personal journal -- both written while Allen served on the 1871 Hayden expedition -- this book would not have been possible. Both documents were part of a large, well-cared-for collection of family papers which from 1936 to 1996 were sent periodically to the college. I was first alerted to the acquisition of Allen's field notebook in the early 1980s by the former college archivist, William Bigglestone. Several years later the remaining and largest share of the collection began arriving, including Allen's personal journal, as the gift of two sisters, Ellen Spears and the late Carolyn Miller. I gratefully acknowledge not only the Spears- Miller gifts but also the effort of College Archivist Roland Baumann, who was instrumental in expediting the acquisition process and provided me with comfortable space for the tedious transcription process of the Allen documents. He and the archival staff, Ken Grossi and Tammy Martin, assisted me in many valuable ways. Bill Bigglestone has shared his considerable knowledge of George Allen with me, and over the years has contributed the kind of support, interest, and advice so needed in preparing this kind of documentary book. I also wish to thank Clayton Koppes, dean of the College of Arts and Sciences at Oberlin College, who showed an interest in my work from its inception and helped provide college funds for the publication of additional photographs by William Henry Jackson.
Wyoming geologist David Love took an early interest in my work and provided me with a master's thesis on Ferdinand Hayden written in 1978 at the University of Wyoming by Sandra Oliver. Oliver's thesis alerted me to the existence of Albert Peale's 1871 Yellowstone journals, which, when combined with Allen's half-finished account of the Yellowstone Survey, made it possible to provide a complete narrative of the survey. Later Dr.