ures. The Echo Cliffs displacement is a flexure. Just over the zone of flexure a long ridge extends from north to south, known as the Echo Cliffs. It is composed of a comparatively hard and homogeneous sandstone of a later age than the limestones of the Marble Canyon Plateau west of it; but the flexure dips down so as to carry this sandstone which forms the face of the cliff (presented westward) far under the surface, so that on the east side rocks of still later age are found, the drop being several thousand feet. The inclined red sandstone stands in a ridge more than 75 miles in length, with an escarped face presented to the west and a face of inclined rock to the east. The western side is carved into beautiful alcoves and is buttressed with a magnificent talus, and the red sandstone stands in fractured columns of giant size and marvelous beauty. On the east side the declining beds are carved into pockets, which often hold water. This is the region of the Thousand Wells. The foot of the cliffs on the east side is several hundred feet above the foot of the cliffs on the west side. On the west there is a vast limestone stretch, the top of the Marble Canyon Plateau; on the east there are drifting sand-dunes. The terraced land described has three sets of terraces: one set on the east, great steps to the Kaibab Plateau; another set on the west, from the Great Basin region to the Kaibab Plateau; and a third set from the Grand Canyon northward. There are thus three sets of cliffs: cliffs facing the east, cliffs facing the west, and cliffs facing the south. The north-and-south cliffs are made by faults; the east-and-west cliffs are made by differential degradation. The stupendous cliffs by which the plateaus are bounded are of indescribable grandeur and beauty. The cliffs bounding the Kaibab Plateau descend on either side, and this is the culminating portion of the region. All the other plateaus are terraces, with cliffs ascending on the one side and descending on the other. Some of the tables carry dead volcanoes on their backs that are towering mountains, and all of them are dissected by canyons that are gorges of profound depth. But every one of these plateaus has characteristics peculiar to itself and is worthy of its own chapter. On the north there is a pair of plateaus, twins in age, but very distinct in development, the Paunsagunt and Markagunt. They are separated by the Sevier River, which flows northward. Their 98 CANYONS OF THE COLORADO. southern margins constitute the highest steps of the great system of terraces of erosion. This escarpment is known as the Pink Cliffs. Above, pine forests are found; below the cliffs are hills and sand-dunes. The cliffs themselves are bold and often vertical walls of a delicate pink color.