2007-01-032022-02-032007-01-032022-02-03http://hdl.handle.net/11124/10470The 'Adit' Tunnel 6/18/81.Date scanned: 2001-09-12.Identifier: NMHFM-659.Related photographs: NMHFM-658, NMHFM-660.Unmounted; text on verso.Held in the National Mining Hall of Fame and Museum.This is probably the adit tunnel for the Big Five Mine, showing mine drainage. The area of Lefthand Creek in the Ward district, Boulder County, Colorado was one of the region's richest gold and silver producers by 1870. The Big Five Mining Group consolidated five mining properties around Lefthand Creek and California Gulch in 1897. The ores from these mines were transported to Camp Frances mills for processing by way of an adit tunnel. Acid mine drainage from the Big Five Adit flows over waste rock, through a settling pond, and into Lefthand Creek. Contamination from the mine and mill areas was found to threaten drinking water supplies in the late 1990s. The area around the Big Five Mine tunnel, mill, and Captain Jack Mine was designated as a Superfund hazardous waste site in 2003.Rights management statement available at: http://library.mines.edu/digital/rights.htmlGold mines and miningMine drainageMiningSilver mines and miningUnderground miningStillImage