USGS Mineral Resources Data System (MRDS)

[JOHNM 22]

i wonder how accurate this system is as far as what the individual minerals have been found at each mine.  i was going to land matters which doesn't tell what mineral  has been found.  MRDS says it was a 2011 survey.  Looking at some of the places these mines were at i can't believe a guy would stay for lead, gypsum etc.   what do you experts think?