This illustration represents the important areas of uppermost Cretaceous, Paleocene, and Eocene nonmarine sediment deposition. The basins and other features (e.g., Cypress Hills) are shown by the distribution of Paleocene sediments. This means the outline of the basins and other features approximates the K/T boundary in the northern Great Plains and intermontane basins (Hartman image basinmap).

This illustration represents the uppermost Cretaceous (green), Paleocene (gray), and lower Eocene (pink) bedrock strata of the Williston Basin and Cypress Hills (of Saskatchewan). Important K/T boundary study intervals are shown in blue-boxed areas (Hartman image Geog12).