Name________________________________________________________________________________
River Systems and Drainage Basins (Watersheds)
Every second, over 500.000 cubic feet of water pour from the Mississippi River into the Gulf of
Mexico. All of this water originally fell as precipitation in places as far away as Montana and
Pennsylvania. Over time, the water flowed through various tributaries of the Mississippi River
System and then flowed into the Gulf of Mexico. Water always flows downhill and all
streams/river eventually end up flowing into the ocean.
In this activity, you will examine the drainage basins (watersheds) for the Mississippi River as
well as other rivers.
Question – Where are several United States river systems and the Great Continental Divide?
Vocabulary
1. River = a large body of water flowing in a channel
2. Stream = a body of water flowing in a channel
3. Tributary = a stream that flows into another stream or large body of water
4. Drainage Basin (Watershed) = an area drained by a river
5. Precipitation = When water falls from the sky
Vocabulary (continued)
6. Mouth of a river = the area where a river flows into the ocean/lake
7. Source of a river = Where a river begins. It is usually at a higher elevation in the
mountains.
8. Continental Divide = a divide separating river systems that flow to opposite sides of a
continent.
9. Base level = the body of water that a river flows into.
Materials
1. A map of the major rivers in the United States
2. Colored pencils
3. A Physical United States map – On page 654-655 of the Heath textbook in the classroom
Procedure
1. Open the textbook to the Physical US map on page 654-655.
2. Locate the mouth of the Mississippi River on the river map. Use a colored pencil to
trace the Mississippi River and ALL of its tributaries onto the map.
3. Any stream/river that leads into the Mississippi is a tributary of the Mississippi River.
These tributaries extend very far away from the Mississippi River.
4. Draw a curvy line around all of the rivers/tributaries you traced onto the map. This
includes all of the rivers/tributaries that flow into the Mississippi River.
5. With a colored pencil lightly shade in the area you outlined in step #4.
6. Label the area you outlines in step #4 “Mississippi River System”.
7. There are two Colorado Rivers on your maps. Be sure to locate the one that starts in
Colorado. Before you do anything, read step #8.
8. Use a different colored pencil to outline, label and shade the Colorado River System.
9. Repeat step #8 for the Columbia River System.
10. Repeat step #8 for the St. Lawrence River System.
11. Repeat step #8 for the Rio Grande River System.
12. Draw a curvy line showing the location of the Great Continental Divide which runs along
the Rocky Mountains.
13. Label the divide “The Great Continental Divide”.
Questions
1. In the United States, what happens to rain that falls west of the continental divide?
2. What three river systems are located along the Great Continental Divide in Colorado?
1.
2.
3.
3. In which river systems are the following rivers found:
a. Snake river__________________________
b. Platte river__________________________
c. Green river__________________________
d. Wabash river________________________
e. Cumberland river_____________________
f. Gila river____________________________
4. What is the source of the water in the St. Lawrence River?
5. In which general direction does the St. Lawrence River flow?
6. The Mississippi River is the base level for which three rivers?
1.
2.
3.
7. What is the largest river that flows through Westchester New York? Where does this
river originate? What is its base level?