The Dean River originates as a small stream high in the Chilcotin Plateau in the heart of British Columbia. It carves its way to the Pacific through the Nimpo and Anahim Lakes area, where numerous rapids and waterfalls impede the upstream journey of Steelhead and salmon. Consequently, the fish population is concentrated in the lower and middle reaches of the Dean River. The Summer Run of Steelhead begins as early as June and extends until the end of September. A canyon near its confluence with the middle section prevents weaker fish from ascending. Only the strong Steelheads, Chinook salmon, and Coho salmon manage to navigate through the canyon into the middle section of the Dean River.