There is a new version of this book available published in 2009. It is completely updated and includes many new charts, figures, and maps. It is a great book, but I am a little biased because I am a co-author on the new edition.
For anyone in Utah with a wish to know about the geology this is great. You can figure out the rocks around you and when and where they came from. If you want to find any particular rocks or gems it is also helpful.
This is a really good read if you are interested in Utah geology. Some of the material is a bit on the technical side, but Hintze does a great job of making it all quite understandable.