The geology and mineral deposits of the Bancroft U camp are reviewed briefly. The relation of the deposits of the one type that has been found to be economic to other types of deposits and to geological features is described. The mineralogy and geochemistry of the ore deposits is described. The ages of the ore deposits, of other mineral deposits, and of the principal igneous rocks of the district are compared. It is concluded that there is a genetic relationship linking the ore deposits to certain granite intrusives, and that the deposits were deposited in major part by replacement controlled by type of rock and structure, and in minor part by fissure filling.