Lewis and Clark Trail History

The Confluence of the Yellowstone and Missouri Rivers

The Yellowstone River drains an area stretching from the Rocky Mountains near Yellowstone National Park across northern Wyoming and southern Montana. On this map you can see it approaching the Missouri River from the southwest, joining with it right after it passes from Montana into North Dakota (the border is the vertical dashed line).

President Thomas Jefferson had specifically commanded Meriwether Lewis to follow the Missouri River to its source, so on the journey westward the expedition didn't try to explore the Yellowstone River. On the return journey eastward, however, Captain William Clark led a small group along the length of the Yellowstone, rejoining the remainder of the Corps of Discovery at the confluence with the Missouri.

A few key historical sites are found near this juncture, memorializing the American settlement of the northwest. The Missouri-Yellowstone Confluence Interpretive Center tells the story of the spot where these two great rivers converge, and provides the same magnificent view that expedition members enjoyed.

Fort Union Trading Post was the most important fur trading post on the upper Missouri from 1828 to 1867. At this fort numerous tribes met and traded buffalo robes and furs for goods such as beads, guns, blankets, knives, cookware, and cloth. At the reconstructed fort, various fur trade personnel are portrayed within the courtyard during summer months.

Fort Buford was built in 1866, and was one of a number of military posts established to protect overland and river routes used by immigrants settling the West. It later became a major supply depot for military field operations, and is probably best remembered as the place where the famous Sioux leader Sitting Bull surrendered in 1881. Original features at the site include a stone powder magazine, the post cemetery, and a large officers' quarters building now housing a museum.