JIM WEST / SCIENCE PHOTO LIBRARY JIM WEST / SCIENCE PHOTO LIBRARY
Jack pump (also known as a nodding donkey) at an oil well. Jack pumps are used for oil extraction where the natural pressure in the oil well is too low to force oil out at an economic rate. Such pumps are now becoming less frequently used as new recovery techniques are developed. Photographed near Denver, Colorado, USA, with the snow-capped Rocky Mountains in the background.
Model release not required. Property release not required.