Surface water sources in southern Alberta are fully allocated and it is projected that groundwater resources will face increased pressure as a result. In order to facilitate the development of a regional land use plan and groundwater management framework, the Alberta Geological Survey is conducting a regional hydrogeological assessment between Calgary, Lethbridge, and the US border. This Calgary-Lethbridge Corridor (CLC) covers approximately 22 000 square kilometers and includes portions of the Bow and Oldman River basins. The CLC was identified as a priority area due to the relatively large population, and increasing agricultural and hydrocarbon development in combination with limited understanding of regional groundwater flow and potential groundwater-surface water interaction. The CLC study will take an integrated approach to deliver a consolidated assessment of the regional hydrogeology, grounded in an updated geological framework. New geological modelling is underway to produce a 3D geological model of bedrock units in the region. Mapping the Neogene-Quaternary sediments overlying bedrock will focus on delineating the spatial distribution and hydrostratigraphy of coarse-grained units (potential aquifers) and fine-grained units (potential confining layers). These geological models can be used in conjunction with hydrogeological information from sources such as the Alberta Water Well Information Database. Regional recharge, which is important for considering the sustainability of groundwater resources will be estimated via a 1D modelling approach. Preliminary results of this study are presented and show a strong dependence on groundwater use from bedrock and buried sands in paleovalleys.