• CENEX oil refinery detail, Billings, Montana
  • CENEX oil refinery detail, Billings, Montana-2
  • CENEX oil refinery detail, Billings, Montana-3
  • CENEX oil refinery, Billings, Montana
  • cooling unit, Praxair plant, Loveland, Colorado
  • distilling tower, Praxair plant, Loveland, Colorado
  • mineral hopper, South Dakota
  • nodding donkey pumps, northeast Colorado
  • oil pipeline pumping station, northeast Colorado
  • Praxair liquid air plant, Loveland, Colorado
  • talc mill detail, southern Montana
  • talc mill, southern Montana
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