| Reference | U. S. GEOLOGICAL SURVEY, U. S. BUREAU OF RECLAMATION, AND SOUTH DAKOTA GEOLOGICAL SURVEY, 1975 , MINERAL AND WATER RESOURCES OF SOUTH DAKOTA, SOUTH DAKOTA GEOLOGICAL SURVEY BULLETIN 16 { STOTELMEYER, R. B., KOCH, C. A., AND MCGREGOR, D. J., 1966 , THE MINERAL INDUSTRY OF SOUTH DAKOTA IN 1964 , SOUTH DAKOTA GEOLOGICAL SURVEY MINERALS REPORT 12 |