"Note to self: Pasty-skinned programmers ought not stand in the Mojave desert for multiple hours."
- John Carmack
A huge wall that the river has carved out from the soft stone over thousands of years. The river used to erode over a meter every year; however, these days it has been reduced to less than 30cm/year and through continued water control and anti-erosion measures it's expected that it can be reduced to about 10cm/year.