Floodplains and Plateaus. The Little Missouri River still flows through Theodore Roosevelt National Park. It winds back and forth like a snake. This is called meandering (me-an-der-ing). In between the bends, or meanders, of the river are broad flat places. The flat areas are floodplains. When the river floods, the water spills into these plains. These flood waters leave soil rich in nutrients. When the flood ends, plants grow again and life returns. These floods do not happen often, and many years pass before the water rises again.