Lewis and Clark in Missouri River Country

By editor

Terry, Prairie County, Montana

On July 30, 1806, Captain William Clark and the members of the Corps of Discovery encamped on the north bank of the Yellowstone River, a little downstream from where it meets the Powder River. This confluence lies near present-day Terry, Montana, where the broad, slow-moving waters of these two rivers carve through sedimentary formations deposited over millions of years. Clark and his men were racing homeward after nearly two years of exploration, eager to reunite with Meriwether Lewis and the other half of their expedition, who had taken a separate route along the Missouri River. The landscape they rested in then was a rich and diverse expanse of plains and river bottomlands, teeming with life and geology that spoke to an ancient and dynamic earth.

The Yellowstone River here cuts through the Fort Union Formation, a sedimentary sequence laid down during the Paleocene Epoch roughly 60 million years ago. The land bears the imprint of deep geological time: layers of sandstone, shale, and coal seams tell a story of ancient swamps and floodplains long vanished beneath the advancing sea. The river’s slow meanders and the Powder’s gravelly tributary channel together form a fertile riparian zone that supports groves of cottonwood (Populus deltoides) and willow (Salix exigua), providing shelter for the abundant wildlife that Lewis and Clark so keenly observed.

Captain Clark’s journals from that day reveal his keen eye for both the natural world and the logistics of survival. He described the region as “the country is as yesterday beautiful in the extreme,” a phrase that captures the timelessness of the plains beneath the vast Montana sky. Their purpose was clear: to find a navigable route to the Pacific, but they were also collectors of knowledge, noting the prolific game in the area. Clark’s crew recorded sightings of bison (Bison bison), elk (Cervus canadensis), pronghorn antelope (Antilocapra americana), and deer, along with smaller mammals like beaver (Castor canadensis) whose pelts were coveted in global trade.

Meriwether Lewis wrote on May 8, 1805, before reaching this region, “We saw a great number of buffaloe, Elk, common and Black taled deer, goats, beaver and wolves... We can send out at any time and obtain whatever species of meat the country affords in as large quantity as we wish...” This observation speaks to the once-thriving populations that roamed the Northern Plains, a richness that modern conservation efforts strive to restore. The wolves he mentions, Canis lupus, played their part in the prairie ecosystem, shadowing buffalo herds to scavenge and cull the weak.

But this serene wilderness would not remain untouched. Over six decades later, the same confluence of the Yellowstone and Powder Rivers found itself a focal point for conflict and military expeditions during the Great Sioux War of 1876-77. Colonel David Stanley, leading a Northern Pacific Railroad survey party in 1872, encountered hostility that was a stark contrast to the peaceful hunting grounds of Clark’s day. Stanley’s report recounts how, on August 22, “just as we were going into camp 20 or 30 Indians concealed themselves behind the rough hills... During this skirmish an Indian calling himself 'Sitting Bull' stood behind a rock on the top of a precipice and addressed us at great length calling over the names of all the bands he would bring to our extermination, his list comprising all the Sioux, the Arapahoes and the Cheyennes.”

Sitting Bull, the Hunkpapa Lakota leader, embodied the fierce resistance of the native peoples against the encroachment of U.S. forces and settlers. The Powder River country became a staging ground for numerous military campaigns aimed at subjugating the Sioux Nation and their allies. In this landscape where the earth’s history unfolded in sediment and stone, human history writhed in conflict and survival.

On July 4, 1876, the ninety-ninth anniversary of American independence, General Alfred Terry and hundreds of soldiers camped near this same river junction, preparing for the campaign that would culminate in the Battle of the Little Bighorn just a few days later. The soldiers built large piles of wood intended for celebratory bonfires, their purpose abruptly overtaken by news delivered that afternoon via the steamboat Far West. The boat carried dispatches of Custer’s defeat, a vivid reminder that this land held power beyond its placid appearance.

The juxtaposition between the Corps of Discovery’s passage and the violent military struggles that followed cannot be overstated. In 1806, Clark’s party saw a land abundant with game and promise, a place where the natural world flourished under the vast sky and ancient geology. By the 1870s, that same land bore the scars of war and the relentless push of expansion. The rivers, the hills, and the plains remained, but their role had shifted from a resource and sanctuary to a contested frontier.

One must also consider the changes to the fauna that Lewis and Clark so carefully documented. The great herds of bison they encountered numbered in the millions, but by the late nineteenth century, these animals were driven nearly to extinction by hunting and habitat loss. The Audubon bighorn sheep that once grazed the rocky bluffs here have vanished entirely from the region, while species like grizzly bears (Ursus arctos horribilis), wolves, and moose have retreated to the more rugged mountain ranges. Efforts to reintroduce elk and bighorn sheep along the Missouri River and near Fort Peck Lake seek to restore elements of the ecosystem witnessed by the original explorers.

The Missouri and Yellowstone rivers themselves, arteries carved through the earth since the last glacial maximum, continue to shape the landscape. Their sediment load, floodplain dynamics, and seasonal rhythms remain vital for the plants and animals that survive here. The geological formations around the confluence -- including exposures of the Cretaceous Hell Creek Formation nearby, famous for dinosaur fossils -- remind us that this land’s story spans far beyond human memory.

Clark’s journey, the military campaigns, and the ecological transformations are chapters of a larger narrative written in stone, water, and living creatures. The Yellowstone and Powder Rivers, flowing steadily through the layers of time and history, invite reflection on how this country has changed and endured. As Clark once noted upon seeing the wildlife, “we can send out at any time and obtain whatever species of meat the country affords,” a truth that was abundant then, challenged now, and one that still informs our understanding of Montana’s natural heritage.

See also

• Lewis and Clark in Missouri River Country at Terry, Prairie County
• Military Camp: Exploration to Annihilation at Terry, Prairie County
• Evidence of the Expedition at Glendive, Dawson County