For the first time, river fishing for sea trout is comprehensively described in a book. The phenomenon of summer river-fjord-river migrators is addressed for the first time in the German-speaking world. The fascination of river fishing lies in the chance to catch one of the large sea trout - every year, fish over 10 kg are caught. However, for many beginners, this type of fishing is a mystery. This book now distills decades of experience and decodes the secrets of river fishing: How does the sea trout behave in the river? What are the best fishing techniques and baits? Where are the typical spots for fish in the river? What influence do water levels, time of day, and weather have? The book provides an overview of the most successful fly patterns for sea trout fishing in the river from world-class fly tier Ulf Sill for the first time.