ned key to the interpretation of American rock art. Interest in the subject has grown significantly among professional archaeologists and informed lay persons in recent years, but the purpose and meaning that the intriguing symbols had for their creators remain a mystery. Although the significance of the symbols will never be known for certain, educated guesses can be made. The "Field Guide" brings together 600 commentaries on specific symbols by over one hundred archaeologists, anthropologists, researchers, and Native American informants. Intended to be used in the field, as well as a reference, the book includes a pictorial key at the beginning and is organized by tentative meaning or by description. The reader can easily find the one or several of the 500 illustrations that most closely match the symbol in question. Patterson emphasizes the tentative nature of the interpretations and has included an index by neutral archaeological description as well as complete documentation of every excerpted comment. The range of the book is from the northern states of Mexico to Utah and from California to Colorado.