the northwestern corner of Wyoming (with portions in southwestern Montana
and eastern Idaho as well), Yellowstone is the
oldest national park in the world. It also has
more geysers and hot springs than any other area
in the world. The park covers 2,219,823 acres.
major volcanic eruption occurred in the
Yellowstone area about two million years ago.
About 600,000 years ago, another explosion of
magma and gas created a huge crater about 40
miles long and 30 miles wide, and that crater is
now occupied by Yellowstone Lake. The lake, which
lies 7,733 feet above sea level, is the largest
high-altitude lake in North America. It measures
about 20 miles long and 14 miles wide. During the
eruption, lava covered more than 1,000 square
miles and formed the broad pateaus that
characterize Yellowstone today.
The Grand Canyon of the Yellowstone cuts
through the landscape for about 20 miles. Carved
by the Yellowstone River, which flows out of
Yellowstone Lake, the canyon reaches a depth of
about 2,000 feet in some places. The river flows
over two waterfalls -- the Lower Falls plunges
308 feet, and the Upper Falls 109 feet.
Yellowstone remains one of the
most volcanically active regions in the world. A
huge mass of magma about two miles below the
surface has erupted at least 27 times during the
past two million years, and remains forever
poised to erupt in a massive explosion again.
That same magma provides heat for more than 200
active geysers and thousands of hot springs, the
greatest concentration of these phenomena in the
North Geyser Basin is the
hottest and most active thermal area in
Yellowstone. The temperature of the water in some
of the springs reaches more than 200º F. Several
of the geysers may erupt at the same time.
Steamboat Geyser set a world record by hurling
its water 400 feet into the air.
Prismatic Spring, in Midway Geyser Basin, is the
largest hot spring in Yellowstone. Its pool,
which has a deep blue center ringed with pink,
measures 370 feet in diameter. Algae is what
gives the edge of the pool its color.
The Lower Geyser Basin includes
the Fountain Paint Pots, a series of hot springs
and bubbling pools of mud formed by steam and
other gases that rose from holes in the ground
and changed the surrounding rock into clay.
Minerals in the clay give the mud various colors.
Great Fountain Geyser erupts from the center of a
large pool. Its bursts of water sometimes spout
200 feet above the pool.
Mammoth Hot Springs, beautiful terraces are
formed by gently flowing waters. The waters
deposit a form of limestone called travertine,
building large terraces one above the other.
Algae and bacteria give some of the terraces
various colors. The terraces change continually
through the years as the waters build them up.
Some springs die, and the terraces become gray.
The Upper Geyser Basin includes Old
Faithful, the most famous geyser in the park,
which erupts on an average of every 65 minutes;
the actual intervals between eruptions actually
vary from about 30 to 90 minutes. The geyser
sends a stream of boiling water more than 100
feet in the air. Other geysers in the area
include Castle, Giantess, Grand and Grotto.
Morning Glory Pool, one of the most beautiful hot
pools in the basin, resembles the flower for
which it is named in both color and shape.
The mountains of the Washburn
Range rise most prominently in the northern part
of Yellowstone Park. Mount Washburn is the
highest point in the park, with an elevation of
10,243 feet. Specimen Ridge has some of the
park's most famous petrified forests. The trees
of this forest were buried by lava ash during
volcanic eruptions over 60,000 years ago.
Minerals from the ash seeped into the trees and
turned them into stone.
Obsidian Cliff is a mountain of
black glass that was formed by molten lava.
Lichens now cover the glass in many places.
Plants and Wildlife
The most abundant tree in Yellowstone is
the lodgepole pine. Forests of Douglas fir,
Engelman spruce, limber pine and subalpine fir
also grow in the park. During the summer, the
mountain meadows display a variety of
wildflowers, including the fringed gentian,
Indian paintbush, monkey flower and mountain
More than 200 species of birds
and over 40 kinds of other animals live in
Yellowstone. Trumpeter swans,
blue herons, white pelicans, bald eagles
and gulls feed on fish in the park's lakes and
rivers. Those fish include cutthroat trout,
gayling, mountain whitefish and rainbow trout.
Elk are the most common of the large
animals in the park. Approximately 20,000 elk in
the park in the summer, and about half of them
stay through the winter. Yellowstone is also home
to about 1,000 bison and 250
grizzly bears. Other large animals in the park
include black bears,
cougars, moose and mule deer.
The Sheepeaters are known to
have lived in the area now encompassed by
Yellowstone Park. Other tribes, including the
Bannock, Crow and Blackfeet crossed the area to
hunt bison and elk.
The United States obtained the
Yellowstone region in 1803 as part of the Louisiana Purchase. John Colter, a member of the Lewis and
Clark Expedition, was probably the first white
person to see Yellowstone; he travelled alone on
foot through the area in 1807 and 1808. Trappers
who later explored the area often returned with
stories of spouting geysers, hot springs and
bubbling mudpots, but no one believed them. In
1870, General Henry D. Washburn, the Surveyor
General of the Montana Territory, led an
expedition to check out the reports of the
trappers. In 1871, a government expedition led by
geologist Ferdinand V. Hayden documented the
unusual features of the park.
On March 1, 1872, President Ulysses Grant signed a bill establishing Yellowstone
Park to preserve its natural resources. Civilian
superintendents administered the park for the
first few years, but they were unable to stop
widespread hunting and trapping there. The Army
took over control of the park in 1886, and a
detachment of cavalry protected the park and its
wildlife until 1916, when Congress established
the National Park Service.
National Park Service http://www.nps.gov/yell
Yellowstone National Park http://www.yellowstonenationalpark.com
President Ulysses Grant
National Park Service
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