Big Four Placer

RAMP, LEN, AND BROOKS, H.C., 1969, PLATINUM GROUP METALS, IN MINERAL AND WATER RESOURCES OF OREGON: U.S. CONGRESS, 90TH, 2D SESSION, COMMITTEE ON INTERIOR AND INSULAR AFFAIRS, SENATE PRINTING, P. 170-171.OREGON DEPARTMENT OF GEOLOGY AND MINERAL INDUSTRIES, 1952, OREGON METAL MINES HANDBOOK, SOUTHWESTERN OREGON--JOSEPHINE COUNTY (2D ED.): OREGON DEPARTMENT OF GEOLOGY AND MINERAL INDUSTRIES BULLETIN 14-C, V. 2, SEC. 1, P. 66-67.DILLER, J.S., 1914, MINERAL RESOURCES OF SOUTHWESTERN OREGON: U.S. GEOLOGICAL SURVEY BULLETIN 546, P. 111-112.RAMP, LEN, AND PETERSON, N.V., 1979, GEOLOGY AND MINERAL RESOURCES OF JOSEPHINE COUNTY, OREGON: OREGON DEPARTMENT OF GEOLOGY AND MINERAL INDUSTRIES BULLETIN 100, TABLE 1.PARKS, H.M., AND SWARTLEY, A.M., 1916, HANDBOOK OF THE MINING INDUSTRY OF OREGON: OREGON BUREAU OF MINES AND GEOLOGY, THE MINERAL RESOURCES OF OREGON, V. 2, NO.4, P. 36-37.