Stream Divides and River Systems
SKILLS AND OBJECTIVES
• Identify the major river systems of the United States and the divides that separate them.
MATERIALS: 5 different colored pencils and Appendix B Physical United States Map, pages 708–709
BACKGROUND: Every second, over one-half of a million cubic feet of water pours from the Mississippi River
into the Gulf of Mexico. This water originally fell as precipitation in places as far away as Montana and
Pennsylvania. Over time, the water flowed through the various tributaries of the Mississippi River system,
working its way to the Gulf. In this exercise, you will examine the watersheds for the Mississippi and other
major river systems of the United States. Most rivers in Virginia flow into the Chesapeake Bay and therefore
are a part of the Chesapeake Bay Watershed.
For 20 points, you will:
 Trace neatly each of the 5 river systems with its own color (5pts.)
 Draw neatly the divide around each river system. (5pts.)
 Lightly shade in each of the five river systems and Label their names (2pts.)
 Answer each question on the back of the map correctly (8pts.)
Please read and follow all Procedures carefully!
1. Find the Potomac, James and Roanoke Rivers which run through Virginia. Trace over each river in
any colored pencil and label their names the map.
2. Locate the Mississippi River on your map using the Physical United States Map as a reference on
pages 708-709. Trace over the Mississippi River and all of its tributaries with a colored pencil of your
choice.
3. With the same colored pencil, draw a circle around the rivers you traced in Step 1. This will
represent the divide or boundary between watersheds. The circled region should include the entire
Mississippi River and its tributaries, but should not include any of the other rivers.
4. In the same color, lightly shade in the circled area representing the Mississippi watershed.
Remember, a River System and all the land that drains into it is called a Watershed!
5. Label the circled area the “Mississippi River System”.
6. Repeat Steps 2-5 for the rivers listed below. Use a different color to outline and lightly shade
each river system. Keep in mind that neighboring river systems share the same divide like a border.
There should not be gaps or “white space” between river systems that are next to each other.
-Colorado River -Rio Grande River -Columbia River
-St. Lawrence River (includes the Great Lakes)
Name: ______________________________________ Date: ______________________ Block: ___________
River System Map – Analysis and Conclusions
1. Draw and label the Erie Canal on your map. (Refer to the image on the board).
a) In 1825 engineers completed construction of the Erie Canal, which connects the Hudson River & Lake
Erie. Does the Erie Canal increase or decrease the size of the St. Lawrence River drainage basin?
_____________________________________________________________________________________
b) Why do you think they built the Erie Canal back in 1825?
_____________________________________________________________________________________
2. Draw and label the Continental Divide on your map.
What is the Continental Divide? ____________________________________________________________
3. What is the water source that feeds the St. Lawrence River? _____________________________________
In what general direction does the river flow? (circle one) NE
SE
NW
SW
4. Locate the rivers in central Nevada. Why don’t you think these rivers flow into the ocean? (think elevation)
________________________________________________________________________________________
5. The headwaters or source of three rivers systems are located in Colorado along the Continental Divide.
Identify the three river systems that intersect in Colorado.
A)___________________________ B) __________________________ C) __________________________
6. The headwaters of three different river systems are also found in Wyoming. Identify the three river systems
that intersect in Wyoming.
A)___________________________ B) __________________________ C) __________________________
7. What topographic feature is the Continental Divide associated with?_______________________________
8. What major watershed are the James and Potomac Rivers a part of?
_______________________________________________________
9. How is it possible that the Susquehanna River, located in PA and
MD, can affect the water quality off the shores of VA?
________________________________________________________
________________________________________________________
10. If a pollutant was placed into a river located at the star, the
pollution would most likely travel into the _____.
a)
b)
c)
d)
Pacific Ocean
Arctic Ocean
Chesapeake Bay
Gulf of Mexico