The Permo-Carboniferous Rocky Mountain Group may be divided into 3 formations. From the top down these are: the Ishbel Formation of Permian age, the Kananaskis Formation of early Middle Pennsylvanian age, and the Tunnel Mountain Formation, mainly of Morrowan age. The Ishbel Formation contains the Middle Permian "Russian" fauna Spirifer osborni Harker, Spirifer (? Choristites) cf. soderberghi Dunbar, Spiriferella cf. saranae de Verneuil, Dictyoclostus cf. neoinflatus Licharew, and Helicoprion sp. A new fusulinid, Schwagerina rapsoni, of low middle Permian age, occurs low in the Ishbel Formation. A Morrowan brachiopod fauna low in the Tunnel Mountain Formation includes Spirifer cf. matheri Dunbar and Condra, Composita cf. subquadrta Hall, and Derbya cf. robusta (Hall).

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