This work investigates the complex life cycle of the Pacific salmon and the ecological pressures threatening their survival in the river systems of the Pacific Northwest. Roderick Haig-Brown, a renowned conservationist and angler, utilizes his deep field knowledge and observational expertise to document the biological imperatives of the Chinook salmon. The text serves as both a scientific account and a plea for the preservation of the delicate river habitats necessary for the species' continued existence.

This text is regarded as a foundational piece of environmental literature that bridges the gap between technical ecological study and accessible nature writing. The author's perspective provides a clear, authoritative look at the intersection of human activity and aquatic wildlife preservation.