Predicting the performance of in-situ recovery processes in the McMurray formation is required to optimize development planning and resource management. These performance predictions are sensitive to many parameters; however, vertical permeability is perhaps the most critical geological parameter. There are many challenges associated with the estimation of vertical permeability: (1) it is difficult to collect representative core measurements, (2) the high viscosity of the bitumen makes it impossible to perform well testing, (3) statistical approaches and the notion of representative elementary volumes (REVs) are challenged by heterogeneities at all scales and (4) the nature of the heterogeneities is variable within different depositional environments. This paper summarizes these challenges, then presents a consistent numerical modelling framework based on core data, core photographs, conventional well-logs, high-resolution image logs and detailed geological interpretation. The framework includes: dividing the stratigraphic column into facies with similar spatial arrangement of sand/shale, constructing high-resolution models of sand/shale, assigning porosity and permeability to sand/shale, calibrating the models to direct measurements, solving for effective horizontal and vertical permeability at the appropriate scale and transferring the results to geomodelling. This framework is described in detail and demonstrated with illustrative examples. Considerations for even better results are discussed.