While Yellowstone is famous for its amazing volcanic and hydrothermal geology, there are many other fascinating geologic features within the park. Immediately south of Madison Junction as you look east, the Madison River displays excellent examples of modern fluvial (river) processes.

 

We sometimes think of rivers as static and unchanging. In reality, they are dynamic and constantly changing course. Point bars, comprised of sand, record the lateral migration of river channels. Oxbow lakes and meander scars indicate previous locations of the river channel in the not too distant past. As the river laterally migrates back and forth, it deposits point bars that become amalgamated into one sand-rich channel belt. It is these channel belts, rather than individual river channels, that are usually preserved in the geologic rock record.