Cordilleran ice sheet

Remember when you played with your sandbox toys and you made a mountain out of sand? Now imagine the whole world covered in mountains made out of ice! That's what the Cordilleran Ice Sheet was like a long, long time ago.

The Cordilleran Ice Sheet was a really big sheet of ice that covered the western part of North America, from Alaska all the way down to California. It was so big that it even covered parts of the ocean!

This ice sheet was formed way before you, your parents, or even your grandparents were born. About 2.6 million years ago, the Earth started getting colder and colder, which caused snow to pile up and turn into ice. This ice covered North America and created the Cordilleran Ice Sheet.

This ice sheet was really heavy, like a giant polar bear sitting on top of the land. It was so heavy that it pressed down on the Earth's crust and created deep valleys and mountains, just like you pressing down on the sand in your sandbox makes little hills and valleys.

Now, you know how ice cream melts when it gets too hot? The same thing happened to the Cordilleran Ice Sheet. The Earth started getting warmer about 15,000 years ago and the ice started melting. The melting ice created huge rivers and lakes that filled up valleys and low-lying areas. Some of these rivers even carved out canyons, like the Grand Canyon in Arizona.

Today, the Cordilleran Ice Sheet doesn't exist anymore. All that remains are the valleys, mountains, rivers, and lakes it created. Scientists still study the Cordilleran Ice Sheet to learn more about the Earth's history and how it changes over time.