How do little streams become a river?

Have you ever dipped your fingers in a little stream? The water feels cold and quick. You can hear it go trickle, trickle over the stones.

A stream is small enough to step across. A river is wide and deep, far too big to jump over. So how do little streams become a river?

High up on a hill, a little stream runs down between the rocks. It runs down because the Earth pulls the water. The Earth pulls you down a slide in just the same way.

On the hills all around, other little streams run down too. Each one follows the ground, lower and lower. The Earth pulls them all toward the same low place.

We call that low place a valley, which means the low ground between hills. A valley is like the bottom of a big bowl. Water from every hill slides down into it.

Down in the valley, one little stream runs right into another. Splash! Now two streams touch each other. What do you think happens to their water?

The two streams join and become one stream. They join because the valley floor has one lowest path, and both waters flow into it. Now that one stream carries the water of two.

Further along the valley, more little streams join in, one after another. Each one brings its own water. With every new stream, the big stream grows wider and deeper.

At last, so much water flows together that nobody can step across it. Now people give it a new name. They call it a river!

Earth pulls little streams into a valley, where they join to make a river. Each stream that joins makes the water wider and deeper.

Trickle by trickle, the little streams from every hill flow on together. Now they are one wide river, rolling through the valley.