The Rivers

The Face of the Land

The framework of America is built around a huge interior lowland that has yielded some of the country's greatest agricultural and mineral wealth. It contains a large portion of its population and is the heart of what politicians like to call "middle America". The region is drained by the Mississippi River and its great tributaries, one of the largest navigable river systems of the world. The Mississippi is the traditional dividing line between "East" and "West". To east and^vest, the land rises to mountain ranges that flank the lowland to either side and separate it from the Atlantic and Pacific Oceans.

The mountain ranges differ substantially from each other. The Appalachians on the east stretch are almost unbroken. They are not high and are set back from the Atlantic by a broad belt of coastal lowland.

While this coastal region contains little in the way of mineral wealth, it was here that the American nation was planted and took root in the 17th century. The original 13 colonies were all located in this belt, and almost half of American history has been played out here. Six states of the region are called New England. It was not until the Revolution (1775—1781) that significant numbers of American settlers began to spill westward across the Appalachians into the interior lowlands.

To the West of the internal basin lies the mighty system of mountains known as the Rocky mountains, — a collective term for all the huge rough country of the western third of the United States. It is part of a global mountain system that encircles the Pacific Basin. Here there is no coastal plain. The mountains along the Pacific coast drop abruptly and often spectacularly into the sea. This part of the country contains some of the highest mountains in North America. It has impressive scenery, considerable environmental variety, and great mineral wealth. It is hardly surprising that much of this western country was settled by adventurous folk in search of quick riches, of freedom from the conventions and traditions of the long-settled East. Its picturesque scenery and history have caused many Americans to see the West as a wild eccentric kind of place, a view reinforced by novelists, artists, and film-makers who have painted the American West in bright uncomplicated colors.

The Mississippi is one of the world's great continental rivers. It flows some 3,970 miles² from its northern sources in the Rocky Mountains to the Gulf of Mexico, making it one of the world's longest waterways. The Missouri is its chief western branch. Where the Missouri pours into the Mississippi from the west, it colors the river deep brown with small pieces of soil. Farther downstream where the clear waters of the principal eastern tributary, the Ohio, join the Mississippi, evidence of the difference between the dry west and rainy east becomes apparent. For miles, the waters of the two rivers flow on side by side, without mixing. Those from the west are brown because they wash away the soil in areas of sparse vegetation. 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.

Like the Mississippi, all the rivers east of the Rockies³ finally reach the Atlantic; all the waters to the west ultimately flow into the Pacific. The line that divides these rivers is called the Continental Divide. There are many places in the Rockies where a person may throw two snowballs, one to the east and one to the west, and know that each will feed a different ocean.

The two great rivers of the Pacific side are the Colorado in the south, and the Columbia, which originates in Canada and drains the north. The Columbia flows with quiet dignity. But the Colorado is a river of enormous fury — wild, restless, and angry. It races and plunges, cutting deeply into the desert rocks. But even the furious Colorado has been dammed and put to work. All the farms and cities of the southwestern corner of the country depend on its waters.

The Rio Grande, about 1,990 miles long, is the foremost river of the Southwest. It forms a natural boundaiy between Mexico and the United States, which together have built irrigation and flood control projects of mutual benefit.

Дата добавления: 2015-04-24