National Uranium Resource Evaluation, Elk City Quadrangle: Idaho and Montana

The Elk City Quadrangle was evaluated to identify and delineate geologic environments favorable for the occurrence of uranium deposits. General surface reconnaissance, low-level aerial radiometric traverses, and geochemical sampling were conducted for all geologic environments within the quadrangle. Determinations of favorability and deposit classification were based on similarity to known uranium deposits. Each environment was categorized as favorable, unfavorable, or unevaluated based on recognition criteria established for the National Uranium Resource Evaluation. The Tertiary Challis Formation was determined to be favorable for the occurrence of volcanogenic uranium deposits. All other geologic environments were determined to be unfavorable, although several areas may warrant further examination.