United States

The United States of America is the third largest country in the world with an area of ​​9.8 million km2 and the third most populous country with 305.8 million inhabitants. The capital city is Washington, D.C. The country consists of 50 states, a District of Columbia and fourteen units. The United States limits the north with Canada south to Mexico and the Caribbean, the east by the Atlantic Ocean and west by the Pacific Ocean, plus the state of Alaska on the south by the Pacific Ocean, north to the ocean? Arctic, eastern Canada and west to the Bering Strait.

At both ends of the country in the east and west are the mountain ranges, the Appalachians in the east and the Rocky Mountains, Sierra Nevada and Cascade Range to the west. Between these ridges is the American plains crossed by rivers and the Nevada desert between the Rocky and Sierra Nevada. The hydrographic network of the United States is the Mississippi with about 3820 km in length and a flow of 12,740 m3 / s at the mouth. Its main tributaries of the Missouri River with a length of 4.130km and the Ohio River of 1,579 km Yukon Rivers in Canada, Rio Grande, Colorado River, Columbia. Apart from the rivers are the Great Lakes, five lakes, which together have an area of ​​238.260 km2. Due to the vastness of the country can find a wide variety of climates, árrtico and subarctic Alaska and Northeast, mild with rainfall throughout the year in the fourth southeast Alpine climate in the Rockies, temperate with dry summers in the coastal peaceful and dry climates and desert steppe in areas between the Pacific and the rocky, rocky, and the basin of the Mississippi.