I wish every bioregion had an overview like this. I particularly appreciated the sections on climate, geology, and plants. The animal sections were a bit underwhelming, as they seemed either too broad and too generic, e.g. entire insect orders treated together with quite a bit of text spent on general descriptions of the group. I also suspect a fairly strong bias toward southeastern Arizona where the Desert Museum (and most of the authors) are based, but that worked well for me since that's probably the part of the Sonoran Desert I wanted to learn about. Of course, now I want to visit more Sky Islands, the Sierra Madres, more of Baja.