Lewis and Clark Camped Here

By editor

Twin Bridges, Madison County, Montana

In the early days of August 1805, the vast and uncharted landscapes of what would become Montana opened before the eyes of Meriwether Lewis and William Clark’s Corps of Discovery. It was here, at the confluence of two powerful rivers--the Jefferson and the Big Hole--that a small but consequential episode unfolded, one that highlights both the unpredictability of wilderness travel and the keen observation and perseverance of these early explorers.

Meriwether Lewis, known for his methodical nature and acute attention to natural detail, had pushed ahead of the main party with three men to scout the river forks. On August 5th, 1805, he reached the point where the Jefferson River, one of the three headwaters of the Missouri, meets the Big Hole River. The rivers themselves cut through ancient Precambrian formations of the Tobacco Root Mountains, their waters carrying sediments worn from rocks aged over two billion years. The Jefferson River flows sluggishly here, weaving through deep gravel beds and reaching across a valley shaped by glacial floods of the last Ice Age.

Lewis, understanding the importance of choosing the correct river route for the expedition’s passage westward, left a message on a green pole planted by the riverbank. The note instructed Clark and the main party to remain on the Jefferson River and avoid the Big Hole fork, which would lead them astray. Yet, nature intervened in a most unexpected way. A beaver, industrious and powerful, cut down the green pole and carried away the message, leaving Clark and his men unaware of Lewis’s guidance.

Clark, arriving two days later with the boats and men, began ascending the Big Hole River. The creek’s current was swift and the banks steep, carved from volcanic basalt and sedimentary layers that spoke of ancient seas and volcanic eruptions. The men pulled their boats upstream for nearly nine miles, straining against the cold, clear water that harbored cutthroat trout (Oncorhynchus clarkii), a native species that would have glistened beneath the surface.

The error was discovered when one of Lewis’s advance scouts intercepted them, informing Clark that they had taken the wrong river. The return downstream was fraught with danger. The swift current and rocky shallows threw Joseph Whitehouse from one of the canoes, an incident that could have ended in tragedy. Lewis described the event with candor in his journal: “Whitehouse had been thrown out of one of the canoes… a great part of our most valuable stores were wet and much damaged on this occasion… all the baggage wet, the medicine box… lost a shot pouch and horn with all the implements for one rifle lost and never recovered…” (August 6, 1805).

The loss of the medicine box was particularly serious, as it contained vital supplies for treating wounds and illnesses in a land far from any established settlements. The shot pouch and powder horn--tools essential for hunting and defense--also vanished in the mishap. These losses underscored the fragility of the expedition’s progress through a wilderness that allowed no margin for error.

Lewis reflected on the disappearance of the note with a dry acknowledgment of nature’s unpredictability: “…arrived at the confluence of the two rivers where I left the note. this note had unfortunately been placed on a green pole which the beaver had cut and carried off together with the note; the possibility of such an occurrence never once occurred to me when I placed it on the green pole…” (August 5, 1805). This simple sentence reveals the constant negotiations between man and environment--the unforeseen forces that shape travel and discovery.

After the mishap, the two halves of the expedition reunited near this spot on August 7th, 1805. The men made camp and took a day to dry their soaked baggage, their tents pitched among cottonwood trees (Populus deltoides) that lined the riverbanks. The cottonwoods, towering and swift to leaf in summer, provided shade and a respite from the scorching sun that beats down upon the Montana plains in August. The air was rich with the scent of sagebrush (Artemisia tridentata) and the distant call of red-tailed hawks (Buteo jamaicensis) circling overhead.

The expedition’s decision to leave one of their dugout canoes hidden in a thicket speaks to their strategic thinking. Dugouts, carved from single cottonwood trunks, were valuable but heavy craft. By stashing one behind brush, they lightened their load for the mountainous terrain ahead, where river travel would give way to portages and overland crossings.

On August 8th, a moment of cultural significance intersected with the natural landscape. Sacagawea, the Shoshone woman who served as guide and interpreter, recognized a high plain to the right of the river. She identified it as near the summer retreat of her people on a river beyond the mountains. This landmark, she told Lewis, was known to her nation as the Beaver’s Head. The name itself conjures the beaver’s presence and the shaping of waterways, a symbolic nod to the animal that had altered the expedition’s path just days before.

The Beaverhead region, characterized by rugged hills and the eastern edge of the Bitterroot Range, would soon reveal its formidable geography to the explorers. The mountains here, composed largely of the Belt Supergroup sedimentary rocks laid down in the Precambrian, towered as natural barriers. These ancient cliffs and valleys, sculpted by millennia of tectonic forces and glacial action, challenged every step of the journey.

Sacagawea’s recognition of her homeland was crucial. It confirmed to Lewis and Clark that they were approaching the territory of the Shoshone people, whose knowledge and assistance would prove indispensable in crossing the Rocky Mountains. Her presence bridged the natural world and the human stories embedded in it--a living link between the expedition and the indigenous cultures deeply attuned to these landscapes.

This brief episode at the forks of the Jefferson and Big Hole rivers encapsulates the complex interplay of observation, error, and indigenous knowledge. It underscores how the expedition moved through a land shaped by deep geological time--rivers cut through two-billion-year-old rock, mountains worn by ice and wind--and how the natural world could both aid and confound the explorers.

Lewis’s journals, with their precise notes and occasional reflections, offer a window into this moment. His words reveal a man keenly aware of how every detail--from a green pole on a riverbank to the scent of cottonwood leaves--could shape the fate of the journey. The beaver that felled the pole was not mere mischief but a participant in the unfolding story of exploration, its actions a reminder of the wild forces that governed this land.

As the Corps of Discovery moved onward from their camp near Twin Bridges, they carried with them not only their supplies and hopes but the lessons of this encounter--lessons about the rivers, the land, and the people who called this place home.

See also

• Lewis and Clark Camped Here at Twin Bridges, Madison County
• Beaverhead Rock at Dillon, Beaverhead County