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GUIDEBOOK OF THE WESTERN UNITED STATES. 



dish band about the foot of the white cliffs. The 

 relation of these beds to the Uinta Basin is shown 

 in figure 37. 



In the vicinity of Rulison the cliffs are very con- 

 spicuous, and from Rulison to Grand Valley the 

 train runs practically at their feet. These cliffs, 

 which tower to a height of 3,500 feet above the 

 railroad, are but the points of long spurs which 

 far back from the river unite in a broad, *unbroken 

 plateau. The upper part of the cliffs is composed 

 of white shale and sandstone known to geologists 

 as the Green River formation. These rocks, al- 

 though originally dark, weather uniformly to a 

 dull white. The base of the cliffs is made up of 

 the maroon shale of the Wasatch formation, which 

 is exposed at several places between Grand Valley 

 and Salt Lake City. As shown in Plate LXIII, 

 the Green River formation makes prominent cliffs 

 on the north side of the valley and occurs also in 

 the high parts of Battlement Mesa, on the south. 

 Its presence is generally indicated by its white 

 color, which shows wherever the cover of brush 

 and trees has been removed. In such places it is 

 soon cut into castellated forms. 



Most of the lower part of the valley is irrigated 

 and produces good crops and considerable fruit. 

 A sloping terrace on the south side of the river, 

 opposite the village of Grand 

 Valley, is irrigated by streams 

 that come down from the higher 

 parts of Battlement Mesa, and 

 the scene here is a pretty picture 

 of rural peace and prosperity. The principal 

 scenic feature is the great white cliff (PL LXIII) 

 immediately back of the village. All except about 

 600 feet at the base of this cliff is composed of 

 shale of the Green River formation, which, aside 

 from its striking color, is notable because it con- 

 tains a large amount of organic material, mostly 

 remains of plants, from which oil may be obtained 

 by destructive distillation. Oil has not yet been 

 produced commercially from this shale, but it 

 probably will be when crude oil from wells be- 

 comes scarcer and the demand for gasoline is 

 greater than it is to-day. This shale has been 



i£ Grand Valley. 



I Elevation 5,104 feet 



C Population 257. 



'^ Denver 404 miles. 



