Mountains are found on every continent in the world. Though there are some single-standing mountains, they are most often found in groups known as mountain ranges. Some mountains arise from volcanic eruptions, while others have been formed by the shifting of tectonic plates. Thus, mountains are commonly seen at the intersection of tectonic plates and in places where the Earth's crust is relatively thin.
The two largest mountain ranges in North America are the Appalachians and the Rockies. The Appalachian Mountains run from Quebec to central Alabama, and they serve as the dividing line between rivers that flow into the Atlantic Ocean and those that flow into the Gulf of Mexico. The Rocky Mountains are found in the western United States and run through Colorado, Utah and Wyoming.
The Andes Mountains are the largest chain of mountains in the world, and they run along the west coast of South America. Another well-known mountain range is the Alps, which are found in parts of Switzerland, France, Germany, Italy, Yugoslavia and Austria. The Himalayas are the tallest mountain range in the world. They are located across southern Asia and form a barrier between India and Tibet. Mount Everest, the tallest peak in the world, is located in the Himalayas.