
As I planned a recent hiking trip to eastern Oregon, I knew I would bring two essential companions: my good old dog, and The Roadside Geology of Oregon by David Alt and Donald Hyndman.
This handy little book explains, in easy layman's terms, the geological processes that shaped our extraordinary state. Interestingly, because it is designed as a travelers' reference, the book is organized by road. So, for instance, as you travel along U.S. Route 26 through Mitchell and John Day, you can flip to the appropriate section of the book and read an explanation of those astonishing red, purple and green cliffs you can see alongside the highway.
The library has several books in the Roadside Geology series. They're great to have along on your next trip.