The year 1955 marks a continued decline in exploration for oil in the United States and in the world as judged from the employment of seismograph parties. The decline indicates that in the United States we have passed an upper limit of action within the framework of exploration practices as they have existed. The precipitate rise of geophysical exploration was due to the effort of exploration companies to be “firstest with the mostest.” The rapid coverage of prospective oil areas in the United States and in world, however, has not resulted in a complete exploration of the sedimentary areas. Many areas may be considered virtually unexplored. In addition, frontiers exist in the search for very-small-relief structures and stratigraphic traps by geophysical methods. Application of improved instruments, techniques, and interpretations to these problems will result in a new phase of sustained exploration with successes going to those with the most complete information and the best ideas. A changing geophysics will occupy an important place in the world petroleum economy, with at least 450 billion barrels of oil yet to be found.