The extreme southern extremities of the two former are composed of mighty precipices of columnarly eroded limestone called the Pink Cliffs.

Here is the beginning of the Terrace Plateaus, likewise bounded by vertical, barren cliffs.

Between the High Plateaus and the parks, the plateaus may be called, for convenience, Mesa Plateaus, as they are generally outlined by vertical cliffs.

This is the case also south of the end of the High Plateaus where, stepping down the great terraces, we arrive at the region immediately adjacent to the Grand Canyon, composed of four plateaus, three of them of mesa character, the Shewits, Uinkaret, Kanab, and Kaibab; and up at the head of Marble Canyon a fifth, the Paria, while still farther to the north-eastward is the Kaiparowitz.

The edges of these Mesa Plateaus, precipitous cliffs, stretch for many miles across the arid land like mountain ranges split asunder.