The Mississippian Lodgepole Formation in the Virden - Daly area was deposited on a northeast-trending carbonate shelf that consisted of interbedded fine-textured fossiliferous (bryozoans and crinoids) limestone and oolitic grainstones with fair to good permeability. The formation is divided into several members, which in the Virden area are: Unnamed, Whitewater Lake, Virden, Scallion and Routledge shale. The pools in the study area are defined by a series of structural highs with little or no observable closure. The oil is therefore likely held in combination structural-stratigraphic traps. The observation that permeable core (1-2 mD) in the oil pools can have no oil staining emphasizes the potential for a stratigraphic component to the trapping mechanism.