A well laid out, enjoyable reference, but quite basic on the science. Would use as a starting point to review possible destinations and get a general overview of what to expect.
If you would like a bit more in-depth information, I would recommend the "Roadside Geology" series (eg. Roadside Geology of Northern California", etc.)
Gorgeous color photographs (1, 2,or 3 photos for each destination).
Good (basic) introductory info on the geology of California and the various regions of California. Perfect for a family road trip.
Beautiful satellite intro maps and maps for each region. Adequate road maps to help locate (generally) most destinations.
Good Glossary in the back (though it would have been great to have an illustrated Glossary for at least some of the words (ex. I don't think a layperson would read the definition of a "reverse fault" and fully understand it, while a small line illustration showing a reverse fault would explain it better.)
Geologic science is not very detailed.
Relatively few destinations(65)for a state as large, diverse, and geologically interesting as California.