Yellowstone national park

YELLOWSTONE NATIONAL PARK

Established in 1872, Yellowstone National Park is America's first national park. Located in Wyoming, Montana, and Idaho, it is home to a large variety of wildlifeincluding grizzly bears, wolves, bison, and elk. Preserved within Yellowstone National Park are Old Faithful and a collection of the world's most extraordinary geysers and hot springs, and the Grand Canyonof the Yellowstone.
HISTORY
The human history of the Yellowstone region goes back more than 11,000 years. From about 11,000 years ago to the very recent past, many groups of Native Americans used thepark as their homes, hunting grounds, and transportation routes. These traditional uses of Yellowstone lands continued until a little over 200 years ago when the first people of European descentfound their way into the park. In 1872 a country that had not yet seen its first centennial established Yellowstone as the first national park in the world. A new concept was born and with it a new wayfor people to preserve and protect the best of what they had for the benefit and enjoyment of future generations.
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For geyser to occur there must be heat, water, and a plumbing system. Amagma chamber provides the heat, which radiates into surrounding rock. Water from rain and snow works its way underground through fractures in the rock.
As the water reaches hot rock it begins torise back to the surface, passing through rhyolite, which is former volcanic ash or lava rich in silica. The hot water dissolves the silica and carries it upward to line rock crevices. This forms aconstriction that holds in the mounting pressure, creating a geyser's plumbing system.
As superheated water nears the surface, its pressure drops, and the water flashes into steam as a geyser. Hotsprings have unconstricted plumbing systems.

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