he winter at Fort Mandan allowed Lewis and Clark to gather substantial information about the upper Missouri country and its people, but they knew virtually nothing about the lands and people beyond the Rocky Mountains. They anticipated a gentle grade from the continental divide westward to the Pacific, drained by the "river of the West."

Imagine their dismay after reaching the pinnacle of the western landscape, the continental divide, only to find the most challenging mountain travel still ahead of them. They were truly traveling without a roadmap.

Read excerpts in the links below from Lewis and Clark's journals to learn of some of the communication challenges and how they were overcome.

Have you ever played "telephone," where you pass some specific message from one person to the next and then compare notes from beginning to end? Think about the requirements for thorough communication and all the challenges faced by the Corps due to language barriers and cultural differences. How thoroughly do you imagine the players in these scenarios to have understood each other?