A Guide to Freshwater Fishes of Oregon is the first authoritative guide to the native and non-native freshwater fishes found in Oregon. It provides identification aids and images for most of the 137 known species and subspecies. Larval and juvenile stages and hybrids are also illustrated for some groups. Many groups of Oregon fishes are difficult to identify because of their size, diversity of forms, or lack of comprehensive study. In addition, ongoing debate remains about the number of species or subspecies in Oregon. This guide makes use of established naming conventions while highlighting apparent biological diversity. This compromise between accepted nomenclature and a system that reflects the true biodiversity of Oregon’s fishes reflects the delicate balance between scientific communication and the organism’s place in nature. Written by a scientist who has studied diversity in marine and freshwater fishes for decades, and beautifully illustrated with the author’s photographs and full-color drawings by renowned “fish artist” Joseph R. Tomelleri, A Guide to Freshwater Fishes of Oregon is as visually pleasing as it is scientifically rigorous. With annotated keys and detailed color illustrations, it will be useful to professional biologists, sportsmen and anglers, and anyone curious about the diversity of freshwater fishes of Oregon