The Waterpocket flexure, represented in the stereogram (Plate II), is better known in detail than any other of the great flexures of Southern Utah. It is far from following a straight line, but like most lines of orographic disturbance swerves to the right and left, while maintaining a general trend. The amount of its “throw”, or the difference in level between adjacent parts of the two blocks which it divides, is inconstant, its maximum being 7,000 feet. At some points the flexed strata are inclined at an angle of 50° while at others their greatest dip is but 15°. Toward the north the flexure twice divides. One of its branches, the Blue Gate flexure, has a throw in the same direction, and by its separation diminishes the throw of the main flexure. The other, the Red Gate flexure, has a throw in the opposite direction, and by its separation increases the throw of the main flexure. Or in other words, the blocks at the west of the main flexure stand higher than those at the east; and of two blocks which lie at the west, that at the north of the Red Gate flexure stands higher than that at the south; while of two blocks at the east, that which lies northwest of the Blue Gate flexure is higher than the one at the southeast. CLIFFS AND PLATEAUS. Let us now return to the topographic map (Plate I) and examine the forms into which erosion has wrought the disturbed strata. Thanks to the aridity of the climate, the erosion has been greatly influenced by the varying texture of the rocks. Every hard stratum, if inclined, stands forth in a ridge, or if level, caps a plateau. The Masuk Sandstone, undermined by the weathering of the Masuk Shale, breaks off everywhere in a cliff which completely encircles the Masuk Plateau. The plateau stands upon the Blue Gate Sandstone, and this breaking off in a cliff upon all sides constitutes another plateau. The Blue Gate Plateau, in turn, rests upon the Tununk, and that again upon the Henry’s Fork. Passing either to the north or to the south from the Masuk Plateau, one descends a great geological stairway, of which each step is a hard sandstone and each riser a soft shale. Toward the Waterpocket flexure the edge of each plateau is upturned, and if one goes westward from the Masuk Plateau, he will cross in the first mile the upturned rocks of all the lower tables. The preservation of the Masuk Plateau is due in part to the fact that it lies in a slight synclinal, but chiefly to the arrangement of the drainage lines. No streams cross the Henry Mountains, but all go around, and the plateau occupies the divide between those which flow southward to the Colorado and those which flow northward to the Dirty Devil.