U.S. Geological Survey Photographic Library
ID. Jackson, W.H. 97
Yellowstone National Park, Wyoming. Mud Geyser in action. The only true mud geyser discovered, 8 miles below Yellowstone Lake. It has a funnel-shaped orifice in the center of a basin 150 feet in diameter and in which there are two other hot mud springs. The flow of the geyser is regularly every six hours, the eruptions lasting about fifteen minutes. The thick, muddy water rises gradually in the crater, commencing to boil when about half-way to the surface, and occasionally breaking forth with great violence. When the crater is filled, it is expelled from it in a splashing, scattered mass, 10 feet in diameter, to 40 feet in height. The mud is a dark lead-color and deposits itself all about the rim of the crater. 1871.U.S. Geological and Geographical Survey of the Territories (Hayden Survey).
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