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?
The Niobrara is a crossroads of habitats where many species are on the edge of their range. 83 eastern species reach their western range limits and 47 western species approach their eastern limits here. Click "More" to visit the Niobrara National River "Nature & Science" page. More...