RIVERS, LAKES, AND BAYS

The United States has many thousands of streams. The longest is the Mississippi. One of its folk names is "father of waters".

Two of the Mississippi's branches, the Ohio River and the Missouri River, also rank among the most important rivers of the world.

Where the Missouri pours into the Mississippi from the west, it colors the river deep brown. Farther downstream, where the clear waters of the principal eastern tributary, the Ohio, join the Mississippi, the difference between the dry west and rainy east becomes apparent. For kilometers, the waters of the two rivers flow on side by side, without mixing. Those from the west are brown with small pieces of soil. The waters from the east are clear and blue; they come from hills and valleys where plentiful forest and plant cover has kept the soil from being washed away.

The long Rio Grande (3,200 km) forms most of the border between the United States and Mexico.

In the northwest, the Columbia River and its chief branch, the Snake River, drain parts of Idaho, Washington, and Oregon. The Sacramento River and its chief branch, the San Joaquin, drain the great valley of central and northern California. The Colorado River and its many branches drain much of southwestern United States. These three river systems have great value as sources of water power.

The Yukon is a river as long as the Rio Grande but considerably greater in volume. It rises in the Canadian Rockies, but in its lower course it flows westward across Alaska to its mouth in Bering Sea.

The United States has thousands of lakes of all kinds and sizes. The northern state of Minnesota, for example, is known as the land of 10,000 lakes.

The Great Lakes make up the largest group of lakes in the country, as well as the greatest collection of fresh-water lakes in the world. Only Lake Michigan lies entirely inside the United States. The Superior, Huron, Erie, and Ontario form a border between north-eastern United States and Canada. They stretch 1600 km from east to west. This is nearly half the distance across the country. The lakes contain about half of the world’s fresh water.

The St. Lawrence Seaway, which the U.S. shares with Canada, connects the Great Lakes with the Atlantic Ocean allowing seagoing vessels to travel 3,861 kilometers inland, as far as Duluth, Minnesota, during the spring, summer and fall shipping season.

Another region of many lakes lies along the Gulf of Mexico and the Atlantic shore. There are hundreds of small lakes and lagoons deep in dark coastal swamps, or protected behind sandy coastal dunes.

A fourth group of lakes lies west of the Rocky Mountains. Some of these lakes are high in the mountains, others are shallow sheets of salty water. The most famous of these salty lakes are the Great Salt Lake, in Utah, and the Salton Sea, which lies about 72 m below sea level in Southern California.

Great bays cut deeply into parts of the United States coast line. There is an almost continuous series of bays along the Atlantic Coast. Many of the deep inlets form excellent harbors. Some of the country's most important ports lie near the heads of these bays. These ports include Boston, New York City, Philadelphia, Baltimore and Newfolk.

The South Atlantic and Gulf coasts have fewer bays. The most important ports here are Charleston, Tampa, Mobile, Galveston and Corpus Christi. Here the harbors are deep enough for ocean-going vessels. The southern coasts also have important coastal river ports, which include Savannah, Jacksonville, New Orleans, and Houston on the Houston Ship Canal.

The Pacific Coast has the fewest bays of any part of the United States coast line. The City of Los Angeles has built an artificial bay to form a harbor for its ocean trade.

Date: 2015-01-02; view: 1702