INTRODUCTION The Mississippi and Missouri Rivers are America's two greatest rivers. In this part we are going to use them to learn some important basic things about rivers in general.
| 1. On a map of the United States locate the Mississippi River. It flows through Louisiana into the Gulf of Mexico. It is one of America's best known rivers. If you look closely where the Mississippi enters the Gulf you may see a number of channels. These are separate outlets of the Mississippi River resulting from the shallowness of water there. This end of the river is called its mouth and the pattern of channels is referred to as the delta. It gets this name because it resembles the Greek letter "delta" which is shaped like a triangle. Can you see how the mouth of the Mississippi forms a triangle? Most rivers do not end in deltas. |
| 2. When we think of a mouth, we usually think of that thing we put our food into! We think of an entrance. Well, with rivers it is the opposite. The mouth of a river is where the water comes out! Where do you think the water goes in? |
| 3. Since the mouth is the place where water flows out, we assume there must also be a place where water flows in. But wait a minute, when we follow the Mississippi up from its mouth, we discover many places where water flows in! Follow the Mississippi north from its mouth. Soon you come to another river that flows into it. What is its name? We call such rivers tributaries; they contribute water to the main river. |
| 4. Find where the Arkansas River flows into the Mississippi. (This is the mouth of the Arkansas.) The Arkansas is a tributary of the Mississippi. Follow the Arkansas River westward as far as you can. Where does it actually begin? This is its source. Since water flows downhill, what do we know about a source? |
| 5. Go back to the mouth of the Arkansas River where it joins the Mississippi. Now walk your fingers north (up) the Mississippi until you come to the Missouri River. (If your map has cities on it, this will be at St. Louis.) This is the mouth of the Missouri River. Does it have a delta? |
| 6. Go "up" the Missouri (west and north). You will pass many tributaries of the Missouri. Together all these rivers supply water to the Mississippi which then drains it into the Gulf of Mexico. You may not always be able to tell it, but each time you meet a tributary, the main river becomes smaller. Why is this? |
| 7. Tributaries of a river are like branches of a tree. They feed the trunk, in this case, the Mississippi. Rivers grow by gathering water from all the land about them. We call this region a drainage basin. It is like a sink where falling rain and snow flows into a drain. Describe the drainage basin of the Mississippi River. After you have gone far enough up the Missouri River you will find a place where it forks. Forks are like tributaries in that they come together, but they are often similar in size. We may think of them as parts of the same river. The Missouri is formed by three "forks." |
| 8. Go back to the Mississippi River and find its source. We call the area around a river source its headwaters. What state are you in when you reach the headwaters of the Mississippi? |
| 9. Now that you have found the Mississippi, Missouri, and Arkansas Rivers, carefully trace each of them in blue. In what state is the source of the Missouri?
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