This is a topic that I very much enjoy reading about so am reviewing in comparison to several other similar books. Callan writes about his decades spent all over California in various settings, which made the book very enjoyable to me. I got to spend some time with him vicariously in the southern Californian desert as well as the mountains of northern California AND even time in the urban setting of Riverside and San Bernardino, which was new to me for this field. In addition to the information on the different geographical settings, or rather along with, there is information about the different animal life of those areas. I learned a lot about fish poaching and using illegal methods of fishing that were interesting as well as info about reptiles. I don't like fishing or hunting and the catch and release program drives me crazy. Poor fish! Oh God I'm caught! No wait......I'm free! oh NOOOO I'm caught again. So what I found interesting was not learning to fish, but rather the ecological implications for the earth and the different methods of poaching. You know it was that old thing that if the poachers would put as much energy into work as they do poaching, they might all be rich. The urban setting was focused on exotic animals often used in the film industry, as well as those just kept by collectors. The reading became more difficult as Callan moved more into larger mammals such as elk, deer, bears, etc. Sorry to be so prejudiced, but I like bears better than fish and hurting them creeps me out more. There was a lot of info on the market for bear gall bladders as medicine. The intricacy of the whole poaching and marketing is pretty amazing and the author goes into detail about the undercover work involved. I found it very interesting especially as I am familiar with the areas covered in the book. The relationships between the poachers was fascinating. The author also talked a lot about the relationships between game wardens as well as relations with other agencies. I very much enjoyed this four star read. Thanks to the publisher for giving me an early review copy of this book. I read the ebook.