Kogan

Kogan lies in the mountains of the upper Selemdzha, near the stream called Dyukh-Kogan. The stream joins the Selemdzha high in its course, where the larger river has the character of a mountain torrent. Forested ridges enclose the upper valley, whose waters flow west to the Zeya and then south to the Amur. Farther downstream the Selemdzha winds through less rugged country on the edge of the Zeya–Bureya plain.