Tchankasndata

Tchankasndata is a Dakota name recorded for the lower Big Sioux River, from its falls to its meeting with the Missouri. The river rises farther north and flows south along the eastern edge of the Great Plains. Its falls cut through hard Sioux quartzite, creating a striking landmark on the river’s course. Below them, the valley continues toward the Missouri, linking the country of the northern prairies with that great waterway.