The National Petroleum Reserve in Alaska (NPRA) lies north of the Arctic Circle on the northern slope of the Brooks Range. Oil seepage on the Arctic Coast was reported in the 1900s, and the hunt for commercial oil deposits began as early as 1921. In 1923 President Harding set aside the western half of the Arctic Slope as Naval Petroleum Reserve No. 4, more recently redesignated as the National Petroleum Reserve in Alaska. Throughout this long history, the U.S. Geological Survey has been the principal source for geological and geophysical information for this area. The 39 chapters of this book are grouped under a number of areas of interest: exploration history; resource assessment; geological framework; geochemistry; geophysics; paleontology; reservoir rocks; and special studies on such subjects as a cultural resources program, engineering geological studies, and a computer data and graphics system.