A complete and consistent set of interpreted formation tops has been compiled for the Cooper Basin, representing wireline log picks that are based on criteria designed to reflect regionally mappable lithological breaks. In addition, some units were identified on palynological evidence. These data employ the stratigraphic nomenclature established twenty-five years ago, with the addition of subdivisions of the Nappamerri Group and an additional informal member in the Patchawarra Formation. Data from this project are now being used by MESA to compile high quality, detailed depth structure and isopach maps for the area.