The main objective of this study is to bring forward the understanding of shallow gas and define prospective areas in the western plains of North America. This study will review geology by mapping structure/ isopachs/ facies edges, review hydrogeology by mapping head distribution, and evaluate exploration potential by mapping DST recoveries, PE plots and identifying exploration fairways and shadow zones using dynamic gas migration modelling. This method termed ‘Dynamic Migration Modelling’ is a tool that allows the calculation of the direction and intensity of gas migration, accounting for the effects of gas buoyancy and water flow. From this modelling "migration cells" for play types that occur in the Western Plains region have been identified. By examining these migration cells, areas which are prospective for gas charge can be differentiated from area with little or no gas prospectivity.