Activity A.3 Rivers, Maps, and Math

Teacher Background

The Amazon basin holds the largest expanse of rainforest on Earth, but the Amazon is not the world’s longest river (that’s the Nile). Nor is the mighty Mississippi North America’s longest river. That’s the Missouri River, which begins at Three Forks, Montana, and flows 2714 miles to near St. Louis. The Mississippi River begins as a stream in Minnesota and travels south for 2350 miles until it drains into the Gulf of Mexico. The combined reach of the Missouri-Mississippi Rivers is 3741 miles—a length exceeded only by the Amazon and Nile Rivers. This Activity lets students compare and contrast rivers and landforms in the Northern and Southern hemispheres, setting a context for the biology and earth science to come.
Students will use printed and online reference materials to identify key rivers of North and South America.

Students will use printed and online reference materials to identify key forests, grasslands, mountain ranges and other landforms in North and South America.

Students will use map scales to compare and contrast the lengths of the Amazon, Mississippi and local river systems (optional).


  • Elevation
  • Longitude
  • Latitude
  • Watershed

  • Blackline Masters of outline map of Central and South America
  • Colored pencils or markers
  • Access to maps of North America, either online or from other texts or atlases
  • Transparencies and overhead marker pens
Ask students which is larger: the Amazon basin or the area of North America drained by the Mississippi River. Show them the watershed of the Mississippi on a map of the United States.
Pair students and distribute atlases or selected atlas pages. Hand out two Central and South America outline maps and have students title one “Physical Features” and the other “Political Boundaries.”

Read the instructions aloud and assign each pair a specialty area.

Have pairs locate and label on the outline maps (one with the political borders and the other with physical features): Guiana and Brazilian Highlands; Amazon Basin; Orinoco River, Rio de la Plata, the Paraguay and Parana Rivers; Lakes Maracaibo, Titicaca, Poopo, and Nicaragua; the Andes Mountains; the Panama Canal; Gulf of Panama and Mexico; the Atlantic and Pacific Oceans; Monteverde Cloud Forest Reserve; and, as featured during Live From The Rainforest, Brasilia, Rio de Janeiro, Belem and Manaus.

Have each pair prepare a transparency showing one special feature of an area: major transportation routes, biomes or ecosystems, watersheds of the Amazon and other major rivers, elevation contours, latitude/longitude including tropics and equator, natural resources, human uses of land, etc.

Have each group display their overhead and explain what they’ve done.

Conduct a full class discussion of completed pair maps, using wall map and transparencies of correct locations. Overlay an Amazon watershed transparency over a US map of the same scale to answer the opening question.

As a follow-up activity, you can assess knowledge by having the class make a jigsaw puzzle of the areas studied.

Divide class into cooperative groups of 3-4 students to work as members of Cartography Teams. In each group there should be a tracer, cutter/gluer, labeler/graphic artist, and question preparer.

Each group represents a country which they will trace as a puzzle piece on a scale that is consistent for all groups.

Each group will glue its piece onto poster board and cut it out.

After labeling their puzzle pieces, the groups can color, design and “dress up” their pieces by filling in major physical features or cities, common plants and animals, etc.

The last group member prepares a question to ask the class relating to the geography of their country.

Groups take turns placing their pieces on the class map, sharing designs and asking prepared questions.

Math Extension
North America/South America Data-hunt (all these facts can be found in the resources referenced below)

Students will compare the Amazon watershed with a local watershed or with that of the Mississippi River.

Have students use string to trace the courses of the Amazon, a local river and/or the Mississippi. Using map scales, calculate the respective lengths of the rivers. Figure out the ratios of the North American rivers to the Amazon.

Prepare transparencies showing the Mississippi and Amazon watersheds on the same scale. Overlay the maps to compare sizes. Calculate the total areas drained in square kilometers or miles using the map scales.

Gather comparable data on the two watersheds and prepare charts or graphs showing data such as the following: square miles of watershed; square miles of farmland, (rain)forest, or open grassland; length of river and its tributaries; number of tributaries; elevation at 100, 500, 750, 1000, 2000, 3000, and 4000 miles from the mouth; gallons of water that enter the ocean; and length of navigable river (by ocean- going vessels).

Compare Landsat images from 20 years ago to current ones and note changes in usage. Calculate the percentage change in type of land use.

Compare the population densities of different areas—rainforest, temperate forest, agricultural, suburban and urban.

Compare the wildlife population—density and/or diversity of two or more areas.

Multimedia Resources specifically suggested for this Activity

Interactive, historical, political and other map resources.

Maps of the Amazon and comparisons.

Mapping activities from the Geographic Education and Technology Programs of the Florida Geographic Alliance.

NASA EOS imaging for educators.

Landsat images—what they mean and a variety of images including before/after in the Amazon basin.

Mission to Planet Earth—how NASA gathers data.

Interactive map-maker.

A fun and easy way to learn about preparing relief maps—color your own online.

A comprehensive site with maps of and information about countries.

Mississippi River info and sources.

“The Amazon: South America’s River Road,” National Geographic, Feb 1995.


Rivers Run Through It (North America, that is)

Some “mighty” Mississippi facts:

The 250 tributaries of the Mississippi drain a total area of more than 1,247,000 square miles—1/3 of the nation’s land mass. It drains almost all the plains between the Rocky and Appalachian Mountains. The Ohio River, the second major tributary of the Mississippi, is formed in Pittsburgh by the junction of the Allegheny and Monongahela Rivers and flows 980 miles to Cairo, Illinois, where nearly 1/3 of the nation’s water drains past the confluence of the Ohio and Mississippi Rivers at Fort Defiance. Here the Mississipi reaches its widest point—4500 ft.

Ninety percent of the fresh water in the Gulf of Mexico comes from the Mississippi, which discharges an average of 612,000 cubic ft per second into the Gulf of Mexico—fifth in the world in terms of water volume.

The river sustains over 5 million acres of forested wetlands. It provides a habitat for 241 fish species. Its bluffs and bottom lands support 45 amphibious and reptile species and 50 mammal species. Forty percent of the nation’s migratory waterfowl use the river’s corridors for their flyway.

Ships can travel along the Mississippi for more than 1800 miles. The river generates close to $2 million annually from commercial fishing, and over $1.2 billion comes from upper river recreation.

The Mississippi River played a major role in the development of America, providing access to the country for Spanish and French explorers, pioneers and traders.

The name Mississippi means “Big River,” and comes from Indian tribes who lived in the Mississippi Valley. Those tribes include the Illinois, Kickapoo, Ojibway and Santee Dakota in the north and the Chickasaw, Choctaw, Natchez and Tunica in the south.