2007-01-032022-02-032007-01-032022-02-03https://hdl.handle.net/11124/7835USBM #40717; Figure 37 Air operated ventilation door, side door for foot traffic.Held in the Russell L. and Lyn Wood Mining History Archive, Arthur Lakes Library, Colorado School of Mines.Date scanned: 2002-08-26.Rights management statement available at: http://library.mines.edu/digital/rights.htmlScenes, undergroundUnderground miningMine ventilationStillImage