Reference | {Deposit:: US BUREAU OF MINES, 1955 , BLACK HILLS MINERAL ATLAS, SOUTH DAKOTA: PART 2 , BUREAU OF MINES INFORMATION CIRCULAR 7707}{Production:: US BUREAU OF MINES, 1955 , BLACK HILLS MINERAL ATLAS, SOUTH DAKOTA: PART 2 , BUREAU OF MINES INFORMATION CIRCULAR 7707 .} |