Camas Cove District
Commodities: gold, silver
This placer district (also called Tyson Creek) is in the southeast corner of Benewah County. The report of the State Inspector of Mines for 1932 lists seven properties there, but no other information is available.
St. Joe District
Commodities: lead, copper, gold
This district (part of which is called Round Top by some) is in the northeast corner of Benewah County, It is crossed by the Chicago, Milwaukee and St. Paul Railroad, but some of the prospects are accessible only by trail. The district (not to be confused with the area of the same name in Shoshone County) is underlain by Belt (largely Prichard) sedimentary rocks out by granodioritic and monzonitic dikes and locally also by lamprophyre and pegmatite, Locally, the old rocks are masked by Tertiary gravel and basalt much younger than the mineralization. Lodes have long been known and intermittently prospected in the St. Joe district, but there has been little, if any, production and none of the mines is extensively developed.
The lodes are replacement deposits in shatter zones in the Belt strata. Pyrrhotite, arsenopyrite, pyrite, sphalerite, galena, chalcopyrite, and possibly tetrahedrite (named in approximate order of decreasing abundance) occur in a gangue of quartz and calcite. The reference in Mineral Resources, listed below (see reference document), show that some placer mining has been done.
