 The formation is the youngest in a group of formations which belong to the Challis Sequence rocks.The formation unconformably overlies rocks of the Eocene Sanpoil Volcanics and much older Triassic and Permian formations.The formation is bounded on its edges by a series of high-angle strike slip faults, which have contained the Klondike Mountain Formation in a series of graben structures, such as the Republic Graben.