Name ______Period ______Date ______Map Activity Stream Divides and River Systems

Background Every second over one-half of million cubic feet of water pours from the Mississippi River into the Gulf of Mexico, This water originally fell a 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 be examining the drainage basins (watersheds) for the Mississippi and other major river systems in the United States.

Map Skills and Objectives  To identify major United States river systems  To locate the drainage divides that form the boundaries of those systems

Materials  Colored pencils  Tracing Paper  U.S.A. Physical Map pg 744-745 in “Earth Science” text book

Procedure (Note: Read and understand ALL instructions before you begin.)

1. Use paper clips to fasten the tracing paper over the map of the major river systems of the United States. Trace the outline of the United States coastline with a black colored pencil 2. Locate the mouth of the Mississippi River on the river map on your data sheet. (Note: the mouth of a river is the point where it empties into a larger body of water.) Use the Physical United States map as a reference. Use a colored pencil to trace the Mississippi River and all of its tributaries on your data sheet map. (Include ALL rivers that are connected to the Mississippi plus the rivers connected to them. You are outlining the ENTIRE river system.) 3. Using the same colored pencil you used in step 1, CAREFULLY draw a continuous line around all the rivers you traced. The area inside this line should include ALL the rivers that flow into the Mississippi River system. THE LINE SHOULD NOT CROSS ANY RIVERS – each of the rivers in the system need to be entirely inside the line, and ONLY the rivers in the system should be included (no parts of other rivers allowed). Note: draw your line around the tributaries – not in and out between them. There should be NO white space between the river systems when you’re finished. Remember: if the water hits the ground, it has to flow either one way or the other, meaning it is part of one of the river systems. 4. Use the SAME colored pencil to LIGHTLY shade in the area. Label the enclosed area Mississippi River System. Be sure your labeling is legible – you might want to make a color key and label in the margin. 5. Repeat step 2-4 for the Colorado River System, Columbia River System, the Rio Grande System, and the St. Lawrence River System. Choose a different colored pencil and use it to outline, label, and shade the each river system. (Note: there are two Colorado River systems on your maps. Be sure to use the one that starts in Colorado.) 6. Carefully draw and label a dashed line showing the location of the Great Continental Divide. 7. Answer the questions in Analysis and Conclusions on your data sheet. Name ______Period ______Date ______Data Sheet: Stream Divides and River Systems

Analysis and Conclusions 1. Draw and label the Continental Divide on your map. What does the Continental Divide Represent? In the continental United States, what happens to rain that falls west of the Great Continental Divide? Rain that falls east?

2. The headwaters of three river systems are located in Colorado along the Great Continental Divide. Identify the three systems.

3. The headwaters of three different river systems are also found in Wyoming. Identify these three river systems.

4. What is the source (where the water flows FROM) of the water in the St. Lawrence River? In what general direction does the river flow? (Be careful with this question – think about which way water ALWAYS flows.)

5. Locate the rivers of central Nevada. Why are these river’s not part of a major river system?

6. Identify the river system on your tracing paper that is closest to your school. Name any source of the waters for this river. Name ______Period ______Date ______