TEACHER INSTRUCTIONS

Part I. The Mississippi & Missouri Rivers

NOTE: Comments and suggestions for the teacher are included with the italicized copy from the student page.

At each step you may be able to illustrate a term or application using rivers and features familiar to your students. Each lesson is designed as a set of pages and each page includes a sequence of steps. You will probably want to have them complete each page independently and then discuss their responses before proceeding to the next page. The final page (fourth) provides for assessment.

SUPPLIES NEEDED: Each student should have a copy of each lesson page (four in total), an expendable map showing major rivers, state outlines, and cities, and blue, green and red pens or markers. A suitable map master is included in the Our Land of Liberty Comprehensive Teacher's Manual or will be sent on request. Be sure to include your mailing address.

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. Teacher notes: You may need to illustrate the Mississippi "delta" with a large map of Louisiana and an illustration of the Greek alphabet. Deltas form where rivers emerge into a shallow basin with such sluggish current and so much silt that the flow does not carry the silt far enough to sea. Deeper, faster rivers seldom develop 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? Teacher notes: Student answers simply reflect their present understanding of river function. We're going to develop awareness that rivers have multiple "sources" including other rivers, watersheds, drainage basins, lakes, and springs. We want rivers to be seen as collectors of water and connecters of places.

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. Teacher notes: To begin associating river sources, we introduce tributaries. The river selected as the first above the Mississippi's mouth will depend on their map. It will probably be the Red or the Arkansas. They are going to trace these rivers in blue on their work maps later, but they could begin doing this now.

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? Teacher notes: It seems obvious, but let's be sure they understand rivers flow downward from higher levels and the ultimate source will be the highest. There is another confusing point emerging: river names do not always reflect the most distant point or largest channel. For example, the Missouri is a tributary of the Mississippi, but is actually longer! We commonly regard the "source" of a river to be the point at which it's name first appears. On the next lesson page, we will see that the source of the Ohio River is the conjunction of two others. The source of the Arkansas is in Colorado.

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? Teacher notes: We may also see the "mouth" of a river as the point where the name ceases. The mouth of the Ohio will be at the Mississippi. Tributaries seldom feed into other rivers through deltas, but may if the conditions permit (low gradient, shallow water, slow current, silt).

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? Teacher notes: As we go up a river, the name usually follows it's main channel. Of course the flow of water down the river is always increased where another river flows into it.

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." Teacher notes: Students should recognize that the "drainage basin" of the Mississippi is not limited to the land surrounding that river. This is key. This basin extends far to the west, all the way to the Rockies and the states of Montana and Wyoming. You may identify the three forks of the Missouri in Montana. On our next page we will expand the Mississippi drainage basin east along the Ohio River.

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? Teacher notes: If they are properly distinguishing river courses they will recognize Minnesota as containing the headwaters of the Mississippi. By now they are using a number of terms to reflect the origins of rivers: source, tributaries, forks, drainage basin, and headwaters. Other origins will be presented on the next page.

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? Teacher notes: Depending on the detail of the map the source of the Missouri may appear in Wyoming or Montana. As stated in #7, it is really at "Three Forks," Montana. A regional map of the northwest or state map may be used to reveal the exact source, (or sources) noting the forks that form it.

Copyright 2000 by Robert C. Law. Permission to copy granted provided this credit line is included:
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Links: Student text for this part - Part 2 - Part 3 - Part 4 - Return to lesson introduction - Home