Abstract
The Bureau of Mines investigated the silver production potential of the Leadville (California) Mining District, Lake County, Colorado, in 1966-67. The mining history of the district, the ground conditions encountered in mining, and the mine-support methods used are reviewed. The drainage problem is discussed in detail. An initial objective was to establish the existence of potential silver resources minable by low-cost open pit methods, particularly in the silver-bearing manganese halos surrounding the major deposits. The report concludes that under present conditions, development of the deposits in the area is not economically feasible; however, a pioneer rotary noncore drilling program demonstrated that this type of exploration is technically feasible. Potential reserves of silver and associated metals are estimated. Possible mining methods for recovery of the reserves are discussed. Future production possibilities from the various subareas of the district are analyzed, considering optimum operating size. Consolidation of small individual holdings for unit operation is recommended. Type of operation, amount of rehabilitation, size and type of concentrating plants required drainage and other mining problems, and metal price trends are discussed as they bear on economic feasibility of development. (Out of print.)
