This report presents a stratigraphic framework within which the Doig hydrogeology has been interpreted. Within the study area, the Doig Formation is a gasifer, or a reservoir in which gas is the continuous fluid on a regional scale. The origin and continuity of the gas charge in the Doig siltstone and sandstones in the study area is addressed, and the regional migration of gas through the Doig Formation is discussed. A definite vertical pressure/ potential gradient exists in the Doig, and that gradient indicates a vertical migration of gas through the Doig Phosphate upward into the Doig and then into the regional Halfway aquifer. The upward migration is facilitated by erosion of the tighter siltstone units by channels at the upper and lower Doig unconformities. Faults and Doig channels, oriented parallel to the direction of regional gas migration, appear to focus the gas flow.