How Are Mountains Made?

Cross section of the Earth.

View of the Mount Everest region from space. Photo: NASA

Most mountains lie close to one another in groups or long lines. Each of the mountains described on the Mountain Fact Sheet is associated with a mountain range. For example, Mount Denali in Alaska is part of the Rocky Mountain range. This gives us a clue about how mountains are made.

The earth is made up of hot melted rock (core), surrounded first by a thick shell (mantle) and then by a thin shell (crust). The crust is beneath all of the continents and oceans that are located on the surface of the earth. Millions of years ago, the crust was in one piece and there was a single continent called Pangaea. Since then the crust has broken into several pieces. These pieces are called plates. Most plates are named for the continent that is located on them. For example, the continent of North America is located on the North American plate.

To begin to understand how mountains are made, you are going to piece the continents back together.