The USA is one of the largest countries in the world in terms of area (at roughly 9.6 million sq km, it's about half the size of Russia) and around the same size as China (though, even with nearly 300 million residents, it's far behind China and India in terms of population).

The continental United States (the 48 states other than Alaska and Hawaii) is bound by the Atlantic Ocean to the east and the Pacific Ocean to the west, with much of the country's population living on these two coasts. Its only borders are shared with Canada to the north, and Mexico to the south. There are three major mountain chains in the U.S., the Appalachian Mountains, the Rocky Mountains and the combined Sierra Nevada and Cascade ranges. The Appalachians extend north from Canada, southwards to the state of Alabama, a few hundred miles (kilometers) west of the Atlantic Ocean. The Appalachians are the oldest of the three mountain ranges, and are not particularly high (the highest peak is 6,684 ft., 2,040 m), but offer spectacular sightseeing and excellent camping spots.

The Rocky Mountains, often simply called the "Rockies," are the highest mountains in North America, extending from Alaska to New Mexico. Much of the mountain areas are protected by the U.S. Government in national parks and are very rural. They offer spectacular natural wonders, hiking, camping, and sightseeing opportunities free from the congestion of the major cities.

The Sierra Nevada and Cascade ranges are the youngest of the three major mountainous regions. The Sierra Nevada extend across the "backbone" of California, and feature famous sites such as Lake Tahoe and Yosemite National Park. Formed by granite bedrock shoved up through the Earth's surface by fault action less than 3 million years ago, the Sierras give way in northern California to the even younger volcanic Cascade range. While the Rockies have the vast majority of high peaks, the highest point in the continental US is Mount Whitney, in the Sierra Nevada; and the fifth-highest, Mount Rainier is in the Cascade range.

The Great Lakes define much of the border between the United States and Canada. Formed by the pressure of glaciers retreating north at the end of the last ice age 10,000 years ago, the five lakes touch the states of Minnesota, Wisconsin, Illinois, Indiana, Michigan, Ohio, Pennsylvania and New York. The great lakes span hundreds of miles, and their shores offer everything from pristine wilderness areas to industrial "rust belt" cities.