Not worth buying and questionable worth reading. Seventy percent of the waters was better detailed in Flyfisher's Guide to Idaho. There were references to areas, but no grid to define what that area covers. Not even references to the Atlas & Gazetteer. No information on where to park or how to get there.
When I saw the pictures of small streams I was very interested in the book. But, it was filled with stories which mostly had nothing to do with out-of-the-way streams.
For 5-10 dollars more, get the Flyfisher's Guide to Idaho. Don't waste money on this book. Mine is going into the trash where it belongs.