Exploration and development activity has increased significantly during the past 5 years in the northern deep Gulf of Mexico. This activity has been caused by several factors, including significant discoveries in deep water (>1500-ft water depth), outstanding reservoir performance in some of these discoveries, expiration of 10-year leases originally purchased in the mid-1980s, innovative production techniques, and new federal royalty relief. Exploration and production has occurred in three general exploration subprovinces: present shelf, deep water, and the subsalt that extends from shelf into upper slope. Each subprovince consists of slightly different geology and, subsequently, different economic scenarios. This paper introduces the geologic setting for a portion of the outer shelf and upper to middle slope region in the northern Gulf of Mexico. The following eight papers demonstrate how the petroleum systems of the deep Gulf of Mexico can be analyzed by using an integrated approach. This issue of the Bulletin includes papers that describe the petroleum geology of the northern Green Canyon and Ewing Bank region: petroleum fields and discoveries, sequence stratigraphy, biostratigraphy, three-dimensional seismic stratigraphic interpretation, structural geology using restorations, interaction of salt tectonics and sedimentation, and geothermal modeling and path migration prediction.