Geology of uranium and associated ore deposits, central part of the Front Range mineral belt, Colorado

The Central City district and adjoining mining areas in the central part of the Front Range mineral belt have supplied small quantities of uranium ore intermittently since the discovery of pitchblende at Central City in 1871. During the early years of development the uranium production form the region was of national importance, and until 1951 the region was this country's principal domestic source of pitchblende. In recent years, however, the production has been insignificant although the search for uranium has been greater than at any previous time. The pitchblende occurs as a local minor constituent of gold- and silver-bearing base-metal sulfide veins, chiefly valuable for their gold content, which have yielded ores valued at about $200 million.