||Western Liard Basin, British Columbia
||The Besa River Formation is a stratigraphical unit of Devonian age in the Western Canadian Sedimentary Basin. The Besa River Formation subdivided into 6 informal lithostratigraphic units composed primarily of dark grey to black, carbonaceous siltstone to shale.
||The Besa River Formation is overlain by the Banff Formation in its eastern extent, while to the west it is overlain by the Mattson Formation and overlays the Dunedin Formation in the west of its extent in British Columbia, and the Slave Point Formation in the east. In the Northwest Territories, The Besa River Formation rests on the Nahanni Formation in the east and the Road River Formation in the west.