244. Yellowstone National Park
Even though they were very volcanic millions of years ago, only a couple was still active today.
In Yellowstone National Park, however, there is a large area of land, which indicates recent volcanic activity.
This area contains hot springs, geysers and mud springs.
Hot springs, like geysers, are caused by underground water being heated by hot rocks down in the earth.
This hot water is then forced to the surface.
When the surface rock is soft or porous, then the hot water bubbles up like a spring.
When the surface rock is hard, then the hot water shoots up through any hole in the rock that it can find.
These spurts of hot water are called geysers.
Yellowstone also contains mud pots or mud springs.
These happen when the hot water is turned to steam, and the steam carries mud and clay to the surface.
Yellowstone Park is high up in the Rocky Mountains of Wyoming.
Very few white people went there until the 1860s.
It is said that Indians avoided the area because they thought that evil spirits lived there.
In 1869, three men from Montana decided to explore this remote area.
They were very impressed with its natural wonders and talked about it to others.
Two other exploring expeditions followed in the next two years.
These visitors were so enthusiastic about the beauty and majesty of Yellowstone
that they asked that it be made a national park.
At that time, there was no national park system in America.
Nonetheless, in 1872, the American government agreed to set aside these lands as a public park.
Why were the early visitors to Yellowstone so impressed?
First, the scenery is spectacular.
The Yellowstone River has created its own Grand Canyon through years of eroding its rocky banks.
It is the yellow color of these canyon walls that gave Yellowstone its name.
The area has many waterfalls, including the 308-foot high Lower Falls in the Yellowstone River.
There are many beautiful lakes, and the largest is Yellowstone Lake.
The area is rich in wildlife.
Among the mammals are black bears, grizzly bears,
elk, moose, mule deer, bison, bighorn sheep,
coyotes, pronghorn antelope, beaver and wolves.
Birds, especially waterfowl, are common all year.
These include the trumpeter swan, blue heron,
cormorants, bald eagles, osprey, pelicans,
Canada geese and many kinds of ducks.
Sport fish are also plentiful.
About 80% of the forests consist of lodge pole pine,
but there are many other evergreens.
Wild flowers are numerous and varied.
But the chief attractions are the geysers and hot springs.
They occur in what was a very volcanic area a million years or so ago.
Here, hot molten lava from the center of the earth has remained close to the surface of the earth.
This lava heats the surface rocks, which in turn, heats the underground water.
The heated water shoots up to the surface as geysers, or bubbles up as hot springs.
The most famous geyser is Old Faithful
which shoots its plume of water 150 feet into the air every 65 minutes or so.
The eruption lasts up to five minutes.
There are 200 geysers in Yellowstone Park and about 50 of them are spectacular.
Some shoot their spray over 200 feet high.
Visitors from all over the world are delighted that this region has been preserved as a national park!