Essential if you are from the Rocky Mountains. In fact, no matter where you are in North America, you could benefit from this book. About 1/3 of the plants are unique to the US Rocky Mountains, about 1/3 apply to anywhere west of the Rockies and about 1/3 are found anywhere in North America. The reason this book is so good is that Harrington is knowledgeable and honest. He explains a lot about each plant, tells you what he used it for, and how he prepared it. He gives you valuable tips, tells you what worked for him and what did not.
This is not a field guide for ‘identifying’ the plants. The line drawings by illustrator Y. Matsumura are technically excellent, but like other books with line drawings, only help if they are supplemented by good photographs. This book has a significant chapter on poisonous plants, which are usually short shrifted by other books. Other chapters are titled “Potherbs”, “Young Shoots”, “Salads”, “Roots and Underground Parts”, “Fleshy Fruits”, “Non-fleshy Fruits/Seeds” and “Miscellaneous – Beverages, Flavors, Smoking…”