For 17 years the late Dr. Herbert J. Pack, former Station Entomologist, made a study of the reptiles and amphibians of Utah. His original idea was to publish a comprehensive treatment of the snakes and lizards of his state, and whenever opportunity was afforded collected data on their distribution, habits, and economic importance. At the time of his death, on January 5, 1930, many notes and drawings of lizards were left; a manuscript on snakes, presented for his master's thesis to the Utah State Agricultural College in 1923, was also in his possession. Bulletin 221 contains essentially the information presented in this thesis. Little attempt has been made to bring it up to date, the thought being to present the material for what it is worth, even though it might not contain references to a few species added to the list of forms known to occur in Utah. Papers by Dr. V. M. Tanner and Mr. A. M. Woodbury add a few species and a number of new localities to the list herein recorded.
Pack, Herbert J., "Bulletin No. 221 - Snakes of Utah" (1930). UAES Bulletins. Paper 182.