What were the years of operation of the mine that a novel group of acidophilic archaea found at?
Archaeal Richmond Mine acidophilic nanoorganisms: Archaeal Richmond Mine acidophilic nanoorganisms (ARMAN) were first discovered in an extremely acidic mine located in northern California (Richmond Mine at Iron Mountain) by Brett Baker in Jill Banfield's laboratory at the University of California Berkeley. Archaeal Richmond Mine acidophilic nanoorganisms:  These novel groups of archaea named ARMAN-1, ARMAN-2 ("Candidatus" Micrarchaeum acidiphilum ARMAN-2 ), and ARMAN-3 were missed by previous PCR-based surveys of the mine community because the ARMANs have several mismatches with commonly used PCR primers for 16S rRNA genes. Iron Mountain Mine:  Geologically classified as a "massive sulfide ore deposit", the site was mined for iron, silver, gold, copper, zinc and pyrite intermittently from the 1860s until 1963.
1860s until 1963