The west-half of the map sheet straddles the Rocky Mountain Trench and is dominated by the Helikian Purcell Supergroup, a thick accumulation of dominantly clastic rocks which forms the core of the Purcell Mountains and is exposed in thrust sheets along the western edges of the Kootenay Ranges. The east-half is underlain by a sequence of essentially unmetamorphosed sediments ranging in age from Helikian to Late Cretaceous. The stratigraphic succession is characterized by abundant carbonate rocks. Concordant intrusive rocks of Precambrian age occur, with less common discordant bodies of Cretaceous or Tertiary age.

Exploration targets are precious and base metals, industrial minerals and coal. Deposit types include sedimentary exhalative (McNeil - 082GSW024), veins (Vine - 082GSW050, Estella - 082GNW008, Bull River - 082GNW002), shear-related deposits, and mineralization related to monzonitic-syenitic intrusives within and east of the Rocky Mountain Trench.

Industrial mineral targets are principally phosphate (Cabin East - 082GSE205), gypsum (Sunrise - 082GSW045) and magnesite (Marysville - 082GNW005). Deposit types include evaporites, veins, replacements and marine sedimentary deposits.