Distribution of Principal Gold Producing Districts of the United States
From 1907 until 1943 byproduct gold, obtained from base-metal ores, formed a small, though significant, fraction of the total production of this country. Only in World War II (1943-45 inclusive), when base-metal production increased and gold mines were closed, did byproduct gold contribute more than 50 percent of our annual domestic production, and since 1951 it has steadily outranked placer production. Most of the byproduct gold is recovered from porphyry copper ores. Large-scale copper mining at Bingham, Utah, has yielded sufficient gold to put this district in second place in annual gold production in recent years. The Lead district, South Dakota, has had the greatest total gold production and was also the largest producer in the United States each year from 1946 through 1965
Of the 508 principal districts, in 1959 about 400 were either dormant or had an annual production of less than 100 ounces. Of the 25 leading districts (listed in fig. 2), 8 are dormant, 5 produce less than 100 ounces annually or have sporadic production, and only 12 of them maintain activity comparable to that of the prewar period.