[en] The Hailey quadrangle in central Idaho lies at the boundary between the Northern Rocky Mountains and the western Cordilleran Physiographic Provinces. The area is dominated by intrusives of the Idaho and Sawtooth Batholiths, but contains considerable exposures of Tertiary and Quaternary volcanics, and Paleozoic sedimentary rocks. Magnetic data apparently show some expression of the intrusives of the Idaho Batholith. Areas of faulted Paleozoic and Tertiary rocks appear to express themselves as roughly defined regions of high frequency/high amplitude wavelengths. The Hailey quadrangle has been unproductive in terms of uranium mining, though some prospects do exist south of the town of Hailey. The quadrangle contains significant exposures of the Tertiary Challis Formation (primarily volcanics) which has been productive in other areas to the north. A total of 161 anomalies are valid according to the criteria set forth in Volume I of this report. These anomalies are scattered throughout the quadrangle. The most distinctive groups of anomalies are associated with Tertiary igneous rocks in the mountainous areas