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 River is the longest river in Nebraska (its total length is 535 miles and it begins in Wyoming). A segment of the middle Niobrara has been designated by Congress as a Wild and Scenic River. More...