This report provides an overview of the intent, procedures, and results of oil and gas exploratory efforts in the Pacific Northwest. It is intended to serve as background material for an ongoing comprehensive evaluation of the petroleum potential of accreted terranes and associated tectonic basins of western Oregon and Washington by the united States Department of Energy, Morgantown Energy Technology Center. To achieve this goal, the report provides a compilation of published material pertaining to the following topics: 1) regional tectonic framework, specifically the origin and subsequent deformation of potentially petroliferous basins; 2) regional sedimentologic framework, emphasizing the origin, nature, and distribution of source rocks and reservoir rocks; and 3) detailed descriptions of the history, geology, and hydrocarbon potential of the areas in which oil and gas have been sought.