From introduction: Approximately fifty radioactive deposits and nearly fifty properties not abnormally radioactive were examined during a geologic reconnaissance for radioactive minerals in Idaho, Washington, and western Montana during the period July 1952 -- June 1955. The most important uranium deposits are in or near granitic to quartz monzonitic intrusions of probable Cretaceous age in central and northern Idaho, westernmost Montana, and northeastern Washington. The purpose of these reports is to describe the geology of the areas so that the possibilities for the disposal of high-level radioactive fluid waste in deep wells can be ascertained.