Name ______Period ______Date ______

Map Activity

Stream Divides and River Systems

Background

Every second, over 500,000 cubic feet of water pour from the Mississippi River into the Gulf of Mexico. All this water originally fell as precipitation in places as far away as Montana and Pennsylvania. Over time, the water flowed through the various rivers and 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

  • Physical United States map, pages 708-709 in your textbook
  • Chapter 13 of your textbook
  • Colored pencils
  • Picture 10.19, Major Rivers of the United States, attached

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

  1. Turn to the Physical United States map,pages 708-709, in your textbook.
  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 Riverand all of its tributaries on the Major Rivers of the United Statesmap, 10.19. (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 2, 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’s part of one of the river systems.

  1. 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.
  2. Locate the Colorado River. Choose a different colored pencil and use it to outline, label, and shade the Colorado River system. (Note: there are two Colorado rivers on your maps. Be sure to use the one that starts in Colorado.)
  3. Repeat step 5 for the Columbia River system, the Rio Grande system, and the St. Lawrence River system. using a different colored pencil for each river system.
  4. Carefully draw and label a line showing the location of the Great Continental Divide.
  5. Answer the questions in Analysis and Conclusions on your data sheet.

Analysis and Conclusions

  1. In the continental United States, what happens to rain that falls west of the Great Continental Divide? Rain that falls east?
  1. The headwaters of three river systems are located in Colorado along the Great Continental Divide. Identify the three systems.
  1. Identify the river system in which each of the following rivers are found:
  1. Snake River......
  2. PlatteRiver......
  3. Green River......
  4. WabashRiver......
  5. Cumberland River......
  6. Gila River......
  1. 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 – and the answer is not “south”!)
  1. Identify three rivers for which the Mississippi River is the base level.
  1. Identify the bay, sound, or gulf that serves as base level for
  1. the Sacramento and San Joaquin rivers......
  2. the Alabama River system......
  3. the Connecticut River system......