A unique feature of the Niobrara is a phenomenon known as surge flow. The river's combination of velocity, gradient, and sediment load cause the formation of sand ridges that result in short-term standing waves. Click for the bulletin on surge flow. You will need Acrobat Reader to open this file.
Surge flow is recorded at one other National Park Service site; Great Sand Dunes National Park and Preserve, in Colorado.
Did You Know?
Tall sandstone cliffs, a rocky streambed and rapids are unusual geologic aspects of this Great Plains River. Click "More" to visit the Niobrara Natonal Scenic River "Nature & Science" page. More...