Where the Yellowstone Meets the Missouri

Southwest of Williston, near the Montana line, two of the great rivers of North America come together. The Yellowstone, running north and east from its origins near the Continental Divide in Wyoming, delivers its final miles here and pours into the Missouri. This confluence has been one of the most consequential geographic facts in the history of the American West.

Meriwether Lewis and William Clark reached this spot in April of eighteen oh five, on their way upstream to the Pacific, and again in eighteen oh six on the return journey. The expedition's journals record the meeting of the waters, noting how large the Yellowstone was beside the Missouri. The Corps of Discovery used the confluence as a landmark and a rest stop; the point where you could turn up the Yellowstone toward the Crow heartland, or continue up the Missouri toward the Mandan, Hidatsa, and eventually the Rockies.

For the fur trade that followed, the confluence was an address. The American Fur Company put Fort Union right at this junction for a reason: every canoe and keelboat and, eventually, steamboat on the upper river had to pass this point. Pelts coming down the Yellowstone drainage merged with robes from the Missouri corridor, and the whole combined harvest moved east from here.

The channel has shifted since Lewis and Clark's time. Garrison Dam upstream on the Missouri, completed in nineteen fifty-four, altered the river's sediment load and hydrology enough that the exact meeting point is not where it was two centuries ago. But the topography remains, and on a clear morning, when the Yellowstone's green-gray water fans into the Missouri's brown current, you can still see what every person who passed this way for ten thousand years saw: two rivers becoming one, and a choice about which direction to go.