Decision Point

On June 2, 1805, the Corps of Discovery made camp under a grove of cottonwood trees on the bank of the Missouri River. From where you are standing you can see the same problem that presented itself to the expedition at this point—the Missouri River seemingly splits into two waterways.

Despite their maps and conversations with traders and local Natives, this major river feature was completely unknown to Captains Meriwether Lewis and William Clark. A mistake could cause the loss of the travel season and jeopardize the expedition as a whole, so a decision would need to be made carefully.

Many expedition members believed the northern branch to be the Missouri, but Lewis and Clark disagreed. Their studies suggested the southerly path was the true Missouri, maintaining that if the Missouri originated in the mountains then its composition would change from a muddy bottom to something more in line with alpine rivers, like the branch to the south.

Lewis travelled northwest while Clark journeyed southwest in an attempt to settle the issue. They each gathered enough information to support the southerly route, Lewis being so convinced he named the northern tributary Maria’s River, in honor of his cousin.

With a decision made the group elected to head southwest. Lewis left first with a small group on foot on June 11 with Clark and the main party following by water the next morning. On June 13, Lewis and his party reached a ridge and saw the spray of the Great Falls of the Missouri rising above the plains. Word was quickly sent back to Clark and the main party letting them know the choice to head southwest was correct.