Before the Lewis and Clark Expedition, Europeans knew little about what lay west of the Mississippi River. The mental maps of expedition members could not prepare them for what lay ahead; nonetheless, they met and overcame numerous challenges in the diverse habitats they encountered.

In this lesson, students will consider how they perceive geographic features and obstacles, and how expedition members might have done so. If possible, begin the lesson before your students see the large-format film Lewis and Clark: Great Journey West or explore the Lewis and Clark Web site, and finish it afterward.

Geography, history

Standard 2: "How to use mental maps to organize information about people, places, and environments in a spatial context"
Standard 4: "The physical and human characteristics of places"
Standard 6: "How culture and experience influence people's perceptions of places and regions"

One hour (not including time to see movie)

• Computer with Internet access (or photocopies of the photo gallery, "Challenges of the Lewis and Clark Expedition")
• Photocopies of the map, "Lewis and Clark Expedition Routes"
• Blank Xpeditions outline map of the United States (two for each student)
• Writing and drawing materials

Students will

• describe and draw their perceptions of geographic features;
• consider what Lewis and Clark might have known or thought about the geography of the West before they began their journey;
• compare and contrast perceived challenges with real challenges;
• realize that perceptions can change based on experience; and
• think about ways people overcome obstacles.

Everyone has "mental maps," the internalized representation of what we know about locations and the characteristics of places. "Maps of the mind" are one way we make sense of the world, and how we store and recover information about the patterns and shapes of physical and human characteristics on Earth. We create mental maps based on what we experience, read, or hear.

Ask students to describe the following habitats: mountain, river, prairie, desert, ocean. Why do they picture these geographic features as they do? Have they seen these features? Read about them? Seen movies or read stories about such places? Have students draw each of these features, and briefly explain why they "see" these features as they do.

Show students the map "Lewis and Clark Expedition Routes." Before Lewis and Clark began their journey, most of the West was unmapped, and Europeans had no idea what the West was like. Lewis and Clark's men believed they would face challenges such as mountains and wild animals—some geographers of the time thought that the expedition might encounter volcanoes, wooly mammoths, or even the Lost Tribes of Israel. Write on the board or an overhead:

• Physical features
• Native groups
• Wild animals

Following are some of the ways people thought about western North America in the early 1800s.

• A "Northwest Passage" existed—a river or series of closely connected rivers that crossed the continent all the way to the Pacific Ocean.
• Western mountains consisted of only a single ridge.
• There were mountains of pure salt, and erupting volcanoes.
• The Indians were blue-eyed people who spoke Welsh.
• Prehistoric animals such as wooly mammoths roamed the land.

Have students use a blank Xpeditions outline map of the United States to draw or map how Lewis and Clark might have pictured these things.

At this point in the lesson, have students see the large-format film Lewis and Clark: Great Journey West or thoroughly explore National Geographic's Lewis and Clark Web site. Have students pay particularly close attention to the trek through the Bitterroot Mountains in a snowstorm, an encounter with the Teton Sioux, the herds of buffalo, and the grizzly bear encounter.

Students can also see photographs of some of the obstacles Lewis and Clark faced in "Challenges of the Lewis and Clark Expedition."

How were students' original ideas similar to or different from the actual encounters? Were the actual obstacles anything like Lewis and Clark might have imagined? Were they more or less dangerous than they had expected? How were Lewis and Clark able to overcome the obstacles they faced?

Ask students to think about obstacles they may have faced in their own lives. Were they prepared to overcome them? How? Remind students that every experience they have helps prepare them for whatever obstacle may lie ahead.

Once Lewis and Clark reached the Pacific Ocean, were they better prepared to face unknown obstacles on the return journey? Either alone or in pairs, have students use new blank Xpeditions outline maps of the United States to draw mountains, rivers, and wild animals, showing what Lewis and Clark actually saw on their trip. Have students write sentences comparing these new maps with the first maps they drew, illustrating how what Lewis and Clark learned on their journey differed from what they had expected. How might they have planned their trip differently if they had had better information about what to expect?

• Consider geographic obstacles students may face in getting from home to school, or from school to a park. How can these be overcome?
  
  
• Do students think Lewis and Clark were adequately prepared to meet the challenges they faced? Were encounters with the land and animals "obstacles"? Were encounters with Native Americans "challenges"? Why or why not?

National Geographic: Geography Action! 2003—Habitats
National Geographic: Lewis & Clark
PBS: Lewis & Clark