The United states of America is the fourth largest country in the world in both area and population. The United States of America is a federal republic consisting of 50 states, one federal district (Washington, D.C.), and one incorporated territory (Palmyra Atoll).The total area of the USA is 3.6 million square miles which is equal to about 9.6 million square kilometres. The population of the USA is about 250 million people. Out of the 50 states, California is the most populous, with an estimated 38,332,521 residents as of 2013;The United States covers the entire midsection of North America, stretching from the Atlantic Ocean in the East to the Pacific Ocean in the west. It is also bordered by Canada And Mexico. It also includes Alaska, in the northwest corner of North America; and Hawaii, far out in the Pacific. The country, excluding Alaska and Hawaii, has three major mountain ranges which traverse it from north to south. Looking at the eastern United States we find the Appalachian Mountains. As geologically old mountains, the Appalachians generally are no higher than about 3500 feet. The Appalachian Mountains extend from the northern trip of Maine southwestward to Alabama. This region has many mountain ranges, such as the White Mountains and the Green Mountains of northern New England. Travelling west, the next great range mountains is the Rockies. The Rockies are geologically younger than the Appalachians and therefore they are higher and more rugged. Finally, near the west coast, you will see both the sierras and the Cascades. The Sierras and the Cascades make up the western coastal range. It is in the Sierras that the highest peak in the US is located. This is Mount Whitney with an elevation of some 14500 feet. As I have known for many years it was thought that Mount Shasta was the highest mountain. But in 1864 the Whitney Geological Survey discovered Mount Whitney to be higher than Shasta. And as you have already guessed probably it was named in honor of Josiah Dwight Whitney, the state geologist and leader of the Geological Survey.
Now, let’s discuss the geography of the land areas that these great mountain ranges divide. We begin with the western coastal range and move toward the east. This huge area basically consists of plateaus and plains. The area between the Coastal Range and the Rockies is most often called the Intermontane Plateau and makes up 1/3 of the area of the country. The area is generally higher and drier than the areas that lie to the east. Further to the east we enter the vast interior lowland. The interior lowland comprises one half of the area of the US. Geographically, this lowland contains three distinct regions. Starting at the Rockies and moving eastward is the great plains, the highest and the driest of the three regions. East of the Great Plains and continuing to the Appalachian Mountains is the Central Lowland. The third region is the Coastal Plain which extends from Texas in the south-west through the Florida peninsula and all the way to New York in the north-east.
The US is a land of rivers and lakes. Mississippi River is the major river the United States (2,339 miles) (3,765 km). It flows from northwestern Minnesota south to the Gulf of Mexico, just below the city of New Orleans. It is a significant transportation artery and when combined with its major tributaries (the Missouri and Ohio rivers) it becomes the third largest river system in the world.
The USA has rich deposits of coal, oil, iron, zinc, copper, silver, phosphate rock, natural gas, uranium and nonferrous metals. The country has one fourth of the world’s coal deposits.
