This book is fascinating, and not just for those who live or vacation in the San Juan Islands of Washington State. The focus is that area, of course, but the geology of this small area is built from many sources far and wide. Therefore, out of necessity, the book must cover global geology as it allowed these parts to accumulate into this area.

This book straddles two different and not entirely compatible audiences. On one hand, it tries to provide comprehensive and detailed coverage of what is known (and what is not yet understood) about the highly complex geology of the San Juan Islands; on the other hand, it tries to present this interesting information in a way that is accessible to casual readers. I think it manages to do both fairly well, although the density of information will serve those with a solid background in geology more than casual readers.

There are abundant photos, maps, and other graphics in the book that are very helpful for understanding the text. At times the need to flip back and forth among pages to find a referenced image was a little frustrating, but I don't think this could be avoided in a print book like this. I could see this information being presented digitally in a way that would streamline the reader experience of referring to supplemental material.

Overall, I'd like to read this book again, to glean information from it that I probably missed on my first reading. Yet I will probably pass it along for my kids to share, because they (like I) spent childhood summers playing on Orcas Island with no idea what was under our feet.