Where Do Mountains Come From? | Geology for Kids

Mountains are made of the same stuff that we're all standing on right now, the hard, rocky layer of the Earth's surface, called the crust. The crust is the crispy, crunchy, rocky part of Earth. The dirt, the rocks, and all of the land on the planet are parts of the crust. It covers the whole Earth, even the land that's underwater.

Unlike bread crust, the Earth's crust isn't all in one piece. It's broken up into pieces, called plates that cover Earth like a giant jigsaw puzzle. These plates are huge and heavy, but they don't just sit there. In fact, they're always moving. They move very slowly, just a tiny bit at a time, about a few centimeters a year. But over long periods of time, all of that moving around can add up to some big changes!

Sometimes, two of the plates in the Earth's crust will move toward each other, and when they do, they start to press against one another. But they have nowhere to go! So they'll just push and push against each other until they start to crumple! Then, the rocks that make up the plates are pushed up and over each other. The more they push together, the more the land rises, and after a while, you have a mountain! And since the plates are so huge, when they push up against each other, they don't just make one mountain, they can make a whole mountain range!

Mountain ranges like the Alps in Europe, the Andes in South America, and Appalachians in the United States were all made this way, by two plates of the Earth's crust slowly crashing into each other! But because the plates move so slowly, it takes a really, really long time for this to happen. I'm talking millions and millions of years!

Some mountains are still growing! Mount Everest, the highest mountain on Earth, grows about four millimeters every year. And you know why? It's because the two plates that make up the land in that part of the world are still slowly smashing into each other. That means that the mountain is just a teeny bit taller this year than it was last year!

The plates of Earth's crust are always in motion, which means that a long, long time ago, the mountains we see today weren't there at all! And the Earth will look different in the future, too! But it will take a really, really long time. So the next time you're walking around on a beautiful mountain, you'll know where it came from!