1. Have students brainstorm human-environment interactions along a river.

To help students access prior knowledge, have them imagine different scenes they might see along a river. Ask: What kinds of land and land use might you see along a river from beginning to end? (Ideas may include cities, wilderness, farms, fishing areas, factories, and homes.) List students’ ideas on the board.

Next, help students see how humans and the environment are linked along rivers. Have students fold a sheet of paper to make three columns. Have them title the first column “Land Use by Rivers,” the second “Impacts on Humans,” and the third “Impacts on the Environment.” In pairs or small groups, have students list 8-10 land use types from the board, then fill in the remaining columns with their ideas. Work through a couple of examples together as a class. For example, for “cities,” the impact on humans might be “flooding of the river could cause damage” or “the river is a peaceful place to watch wildlife”; the impact on the environment might be that “trash and other pollution can be washed into the river.” For “farms” the impact on humans might be “Water is available for crops”; an impact on the environment might be “fertilizers run off into the river.”

2. Have students arrange the River Puzzle pieces.

Give each pair of students the River Puzzle handout, and have them cut along the lines to make the pieces. Looking at their brainstorming ideas, the notes you wrote on the board, and the puzzle pieces, have students add to their list any new ideas for land use along a river. Have each team place the “source” piece, the beginning of a river, near the top of a large sheet of construction paper and the “mouth” piece, the riverʼs end, near the bottom. Each pair then arranges the remaining pieces to show how they imagine a typical river flows.

3. Have students share their rivers.

Have each pair join with another pair of students and have them compare their rivers, describing why they arranged them the way they did. Students can rearrange pieces if they’d like. Then, have a whole class discussion with volunteers sharing their river flow. Help students think about where rural, urban, and suburban land uses are typically located. Pairs can have one more opportunity to move the puzzle pieces around until they're satisfied. Ask students to tape the river to the construction paper.

4. Have students discuss impacts of human activity on a river.

Discuss as a class how different activities or land uses along a river could affect people, animals, and plants downstream—in the direction of, or closer to, the mouth. Write the following questions on the board as prompts:

• In what ways do people use rivers?
• Which activities in a riverside town could affect the river?
• Where along a river would water be clean for swimming or fishing?
• How might farming affect the water in a river?
• How might building a dam or water treatment plant affect a river?
• What could happen to a river when a factory is nearby?

5. Have students reflect on the path of a river from source to mouth.

Ask each student to complete his or her reflection on a piece of paper. You may want to collect students’ reflections to assess their understanding of the topic.

Have younger students imagine being a drop of water moving along the river they created. Ask what the drop would experience on its journey. Prompt students to describe sights in and out of the water, smells, water temperature, and more. How would people’s actions affect the drop of water?

Have older students envision a boat ride down the river from the source to the mouth, describing sights, sounds, smells, human impacts and modifications to the land, and other characteristics observed on the journey.