Williams (1995) and Froede (1996) provided a dramatic example of rapid cliff formation by cliff sapping, a very rapid form of erosion. A comparison is made with a larger set of cliffs, eroded in an earlier time at Colorado National Monument. The author envisions the development of West Central Colorado topography in two phases: first, the retreat of Flood waters, carving the broad valleys (Shaver, 1998); and, second, a period of catastrophic post-Flood erosion, producing features such as the cliffs at Colorado National Monument. Catastrophic sapping may have applications to other sites in the Colorado Plateau region.