Rocky
Mountains
The Rocky Mountains, or Rockies, is a name
given to a series of mountain ranges running down the west-centre of North America from
Alaska to Mexico. Their proper geological name is the Cordilleran Province. The real
Rockies are just in Colorado, Wyoming and Montana. Some mountains have gentle slopes with
rounded tops, but others are tall with jagged rocky peaks, many over 4000 metres above
sea-level. Between the snow-capped peaks lie wide valleys, plateaux, lakes and rivers. In
places there are hot springs, such as the geysers in Yellowstone National Park. The range
contains some of the most dramatic scenery in North America. The roads and railways that
cross them go through spectacular passes among the mountains.
The Cordillera started to form 190 million years ago, and is still slowly rising. As the
land rises, rivers cut deep valleys and canyons in places. The mountains separate rivers
flowing east, such as the Missouri, from those flowing west, like the Colorado river.
Life in the mountains
The region is home to 5 million people. There are deposits of metals such as iron, silver,
gold, lead and zinc, as well as uranium, phosphates and other salts. There is also coal,
oil and natural gas. Some rivers have been dammed to produce hydroelectric power. Other
places suffer from shortage of water. The winds blowing from the west bring rain to the
western slopes, leaving the central and eastern slopes dry.
The alpine meadows are full of wild flowers. Below the meadows, there are forests, and
cattle and horses graze on the grassy lower slopes. Many large mammals live in the
mountains and forests: grizzly and brown bears, cougars (also called pumas or mountain
lions), elk, deer, Rocky Mountain goats and wild mountain sheep. One of the most important
sources of income is tourism, including skiing, fishing and walking in the many national
parks.
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Mississippi River
The Mississippi River together
with its main tributary, the Missouri, is the largest river system in North America. The
Mississippi–Missouri flows a total 6019 kilometres (3740 miles) and drains an area of
3,221,000 square kilometres (1244,000 square miles). Every day it discharges 1600 million
tonnes of water into the Gulf of Mexico.
The Mississippi rises in Lake Itasca, west of the Great Lakes, and is itself 3779
kilometres (2348 miles) long. As well as the Missouri, which rises in the Rocky Mountains,
other large tributaries are the Ohio River which starts in the Appalachian mountains and
the Arkansas River. As it flows towards the sea, the Mississippi grows from a clear stream
winding its way through lakes and marshes, to a huge muddy river over 21/2 kilometres
(11/2 miles) wide, which wanders in huge sweeping curves across its flood-plain. The huge
amount of sediment carried by the river has built up a wide delta pushing out into the
Gulf of Mexico near New Orleans, and the river splits into hundreds of tiny rivulets as it
meanders over the delta.
In the first half of the 19th century the Mississippi was very important to the economy of
the South and Middle West of the USA. Steamboats carried cargo and passengers, and
showboats brought theatre to the waterfront towns. It was a colourful and glamorous
period. But after the American Civil War and the coming of the railways the Mississippi
never quite regained its former glory.
It is still an important highway for transporting cargoes of iron, steel, coal, petroleum,
chemicals and other raw materials and industrial products. In places, the river has been
straightened and its banks have been raised to improve the passage of river traffic and
hold back flood water.
(taken from
"Oxford Children`s Encyclopedia", OUP 96)
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