The thin layer of gravel at your feet rests on colorful layers of
slippery bentonite clay. Because bentonite swells when wet,
exposed badlands slopes tend to slump away along fracture
lines, collapsing the canyon back toward its rims. Notice the
mounds of slump material at the base of the painted hills.
The dry streambed in the canyon floor is more typical of
desert erosion. After sudden storms in the mountains, flash
floods roar down the channel, carving the canyon deeper and