Environment

The continental US stretches across North America 'from sea to shining sea'. There are three major mountain ranges: the Appalachians in the east, the titanic Rocky Mountains in the west and the Sierra Nevada along the border of Nevada and California. The country has abundant natural resources and vast swathes of fertile soil.

The Atlantic Coast is the most heavily populated area and retains strong traces of its European heritage. This is where the oldest American cities such as Boston, New York, Washington and Philadelphia are located, and where most of the major events in early American history took place. The central northeast is marked by the humongous Great Lakes (Superior, Michigan, Huron, Erie and Ontario), which occupy an area larger than most European countries. The rivers and canals linking the lakes to the Atlantic Ocean made virtual seaports out of midwestern cities like Chicago and Detroit.

The central area drained by the Mississippi, Missouri and Ohio Rivers is the grain basket of the country. Farther west, on the Great Plains, are the country's chief grazing areas. This is cowboy country, though today the trusty steeds tend to be battered pickup trucks rather than hi-ho Silvers. Desert predominates in the southwest, where the climate and degraded soils keep population density to a minimum, and where you really don't need much of a wind to see tumbleweed bouncing across the highway. Cross the Sierra Nevada and you're on the West Coast, which was settled by Americans only 150 years ago but has been on a headlong rush into the future ever since.

The USA borders Canada to the north and Mexico to the south. Alaska juts out from northwestern Canada; Hawaii lies 2500 miles (4000km) off the country's western coast, in the middle of the Pacific.

With such varied topography, the US has extremely diverse ecosystems. The most impressive flora are the huge sequoias of the West Coast, some of which are believed to be the oldest living things on earth. The eastern states are home to leafy hardwood forests of maple, oak and elm, which burst into colour in autumn.

The largest land mammals, such as black and grizzly bears, elk and deer, roam the northwestern states. The southern states are home to some of the most interesting fauna, including the marsupial opossum and the alligator. Beasties to avoid include rattlesnakes, bears, wild boar, alligators and Hank, a gas station attendant from Perth Amboy, New Jersey.

The USA is a federal system, and powers not delegated to the federal government by the Constitution are retained by the states. Nevertheless, the powers of the central government have increased over the years relative to those of state governments. Each state has its own constitution and a government that generally mirrors that of the federal government. The governor is the state's chief executive, and a state senate and a house delegation enact state laws (Nebraska alone has a unicameral state government), and a state police and court system enforce them. Among other things, states are responsible for education, criminal justice, prisons, hospitals, administration of elections, regulation of commerce and maintenance of highways. Many of these things are now done in cooperation with federal government, especially for funding purposes.

The states are further divided into counties, boroughs, parishes, cities, towns, school districts and/or special districts that provide services like police, sanitation, schools and so on. Local government units often combine to administer a large urban area as a single unit, as in the five boroughs of New York City.