Your Quick Guide to Identifying Butterflies in the Northwest At the park, in the garden, or on a walk, keep this tabbed booklet close at hand. Based on Jaret C. Daniels’ best-selling butterfly field guides, Butterflies of the Northwest features only species seen in Alaska, Idaho, Montana, Oregon, Washington, and Wyoming. It's organized by color for quick and easy identification. Narrow your choices by color, and view just a few butterflies at a time. The easy-to-use format and detailed photographs, with key markings of more than 100 species, help to ensure positive ID for even casual observers. The pocket-size format is much easier to use than laminated foldouts, and the tear-resistant pages help to make the book durable in the field.