The discovery well for the Prudhoe Bay field, the largest oil accumulatn yet found in the United States, was drilled on the Arctic coast of Alaska by ARCO and Exxon in 1968. A decade of exploratory geology and increasingly detailed geophysical surveys, mostly by Sinclair and British Petroleum in the early years, but then by a number of companies, preceded the discovery. Systematic U.S. Geological Survey (USGS) reconnaissance of the Brooks Range—the great mountain system of northern Alaska—had begun in the 1940s and was accelerated after the discovery, as was industry work. In the last decade, scientists from the Alaska Division of Geology and Geophysics and from various universities have become increasingly involved. This modestly priced two-volume work presents hitherto unavailable summaries of much of this modern work.