NPS photo

Surge Flow Waves

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.