PHYSICAL FEATURES OF COLORADO VALLEY 



533 



Conceive of three geographic terraces, many hundretl feet high, 

 and many miles in width, forming a great stairway, from the Toom'- 

 pin Wu-near' Tu-xoeap'^ below, to the valley of the Uinta, above. The 

 lower step of this stairway, the Orange Clifi's, is more than 1,200 

 feet high, and the step itself is two or three score miles in width. 

 The second step, the Book CliiFs, is 2,000 feet high, or more, and a 

 score of miles in width. The third, or npper step, is more than 2,000 

 feet high. Passing along this step, for two or three score miles, we 

 reach the valley of the Uinta ; but this valley is not 5,000 or 6,000 

 feet higher than the Toom!-pin Wu-near' Tu-ioeap\ for the stairway 

 is tipped backward. 



Climb the Orange Cliffs, 1,200 feet high, and go north to the foot 

 of the Book Clitfs, and you have gradually descended, so that at the 

 foot of the Book Cliffs you are not more than ICO feet above the 

 foot of the Orange Cliffs. In like manner the foot of the Brown Cliffs 

 is but 200 feet higher than the foot of the Book Cliffs, and the 

 valley of the Uinta is not quite 300 feet higher than the foot of the 

 Brown Cliffs. 



To go by land from the valley of White River to the Toom'-pin 

 Wu-iiear' Tu-weap\ you must gradually, almost imperceptibly, climb 

 as you pass to the south, for a distance of forty or fifty miles, until 

 you attain an altitude of 2,500 or 3,000 feet above the starting-point. 

 Then you descend from the first terrace, by an abrupt step, to a lower. 

 Still continuing to the south, you gradually climb again, until you 

 attain an altitude of more than 1,000 feet, when you arrive at the 

 brink of another cliff, and descend abruptly to the top of the lowest 

 terrace. Still extending your travels in the same direction, you climb 

 gradually for a third time, until you reach the brink of the third line 

 of cliffs, or the edge of the escarpment of the lower terrace, and here 

 you descend by another sudden step to the plane of the river, at the 

 foot of Labyrinth Caiion. In coming down by the river, of course 

 you do not ascend, but you pass these terraces along the plane of the 

 river, the upper terrace through the Caiion of Desolation, the middle 

 terrace through Gray Caiion, and the third through Labyrinth Canon. 



The bird's-eye view (Fig. 1) is intended to show these topograph- 

 ic features. The escarpment below, and in the foreground, repre- 

 sents the Orange Cliffs, at the foot of Labyrinth Caiion ; the second 

 escarpment, the Book Cliffs, at the foot of Gray Caiion ; the third, 

 away in the distance, the Brown Clifls, at the foot of the Caiion of 

 Desolation. It will be seen that the three tables incline to the north, 

 and are abruptly terminated by cliffs on the south. For want of space 

 the whole view is shortened. 



In the three caiions there are three distinct series of beds, belong- 

 ino- to three distinct geological periods. In the Caiion of Desolation 

 we have Tertiary sandstones; in Gray Caiion, Cretaceous sandstones, 

 shales, and impure limestones ; between the head of Labyrinth Canon 



