Southwestern Manitoba lies along the northeastern flank of the Williston Basin. The pre-Mississippian strata of southwestern Manitoba comprise a wedge of sediments that attain a maximum thickness in the southwestern corner of the province, and are progressively truncated to the east and north. This erosional truncation forms a series of progressively older subcrop and outcrop belts towards the northeast. These strata contain numerous beds that have reservoir characteristics comparable to productive stratigraphic equivalents elsewhere in the Williston Basin. Southwestern Manitoba is favorably situated for the occurrence of stratigraphic and structural features necessary to provide trapping mechanisms. Limited deep drilling has revealed numerous examples of geological conditions analogous to those instrumental in providing trapping mechanisms in typical pre-Mississippian Williston Basin play types. The migration characteristics of Williston Basin oil-source systems and the occurrence of numerous shows in the pre-Mississippian of southwestern Manitoba suggest evidence that these strat have been charged with hydrocarbons from deeper basinal sources. The stratigraphic distribution of these shows is consistent with that of pre-Mississippian pools elsewhere in the Williston Basin. There is evidence that reservoir development, trapping mechanisms, and hydrocarbon charge are present in the pre-Mississippian strata of southwestern Manitoba. Potential exists for large reserves of high-quality oils at relatively shallow depths. This area has been very sparsely explored and offers a somewhat unique and exciting exploration opportunity.