The Belle Fourche River was the primary erosional agent of the sedimentary rocks around Devils Tower. Today, the river is a “meandering river,” consisting of a series of horseshoe-shaped meander bends.
The Belle Fourche River continues to erode Devils Tower, slowly cutting away at the tower’s southern flank. The river also deposits sediments, forming stream terraces.
To hear more about erosion and deposition along the Belle Fourche River, listen to a ranger talk.