From David Briggs, History of the Silver Bell Mining District, Pima County, Arizona: "Over the past 150 years, the Silver Bell mining district evolved from a collection of small, intermittent, poorly financed and managed underground mining operations that struggled to make a profit from high-grade ores; to a small but profitable producer, deploying innovative mining practices and advancements in technology to successfully develop the district's large, low-grade copper resource." Online at http://repository.azgs.az.gov/uri_gin/azgs/dlio/1714 .
Photographer: ADMMR
Photo Date: circa 2005
Photo Location Accuracy: Known Location
Photo Tags: copper, Cretaceous, mining, porphyry copper, Silver Bell 
