This interim report is designed to show the present status of the Geological Survey's information and the parts of a comprehensive program necessary to improve our information about the raw material resources of uranium and thorium. Rarely in geologic work has it been necessary. to determine so completely a nation's resources of useful minerals in so brief a span of time. Ordinarily, information on mineral resources Is accumulated during a long period of years. However, uranium and thorium were suddenly thrust from a position of subsidiary economic interest into one of great strategic importance. Information concerning their occurrence must, therefore, be obtained as rapidly as reliable methods of investigation will permit. Accordingly the program must be at once comprehensive and carried out over an area more extensive than is usual in the search for and appraisal of most other mineral resources.