Despite the Bakken having been long recognized as one of the richest source rocks for oil and gas in North America, numerous questions remain about the character of the reservoir, the controls on production, the limits of the play, the timing, emplacement and trapping of oil, and the relationship of the reservoir units to other Bakken zones. This study attempts to answer all of these questions using an integrated geological, sedimentological, petrological, petrophysical and hydrogeological approach. The study covers the northwestern corner of North Dakota, from T141N, R88W to the Montana and Canadian borders.