DENVER & BIO GRANDE WESTERN ROUTE. 



197 



of radium are obtained, and one of the most productive districts lies 

 in Paradox Valley, Colo., 15 or 20 miles east of the La Sal 

 Mountains. 



The low hills of McElmo rocks seem endless, but finally they are 

 passed, and at milepost 501 the railroad cuts through the Dakota 

 sandstone, which dips about 30° W. Next it enters the Mancos shale, 

 which the traveler last saw at Mack, before he entered Ruby Canyon, 

 and the features of the surface now become more subdued and softer, 

 and he has a better opportunity to see what surrounds him. To the 

 north he will see the familiar Book Cliffs, but they are so far away 

 that their character is scarcely apparent. HoweAer, they swing to 

 the south around the great anticlinal point through which Ruby 

 Canyon is cut. and in 15 or 20 miles they will be so near the track 

 that the}^ can be clearly seen. 



At the place where the railroad crosses the Dakota sandstone, at 

 milepost 501, it is within a mile of the great bend which Colorado 

 River makes to the northwest, but despite its nearness the river lies so 

 deep in its canyon that it is not visible from the train. Three miles 

 beyond this point is the village of Cisco, which is 

 one of the largest shearing and shipping points in 

 this great sheep-herding country. One unfamiliar 

 with this region might think that there was little 

 or no pasturage here for even a sheep, but when 

 rain falls the country is green with grass, and even in times of 

 drought there are forage plants that might not be noticed by the 

 unaccustomed eye. 



After the train passes Cisco the La Sal Mountains are in plain 

 sight, and the traveler may see the great red wall on the east and also 



Cisco. 



Elevation 4,375 feet, 

 Population 95. 

 Denver 504 miles. 



tain.s the remains of immense reptiles 

 (dinosaurs). 



West of the mountains a similar as- 

 semblage of fresh-water sandstones 

 and shales lies immediately beneath 

 the Dakota. Undoubtedly this forma- 

 tion is in part equivalent to the Mor- 

 rison, but as it is supposed to contain 

 lower beds than the Morrison it can 

 not be considered exactly efiuivalent, 

 so it was called the Gunnison forma- 

 tion. 



Later, in working out the succession 

 of formations in the San Juan Moun- 

 tains in southwestern Colorado, Cross 

 found that beds nearly equivalent to 

 the Gunnison were greatly expanded, 

 especially in the lower part, and he 

 80697»— 22 14 



felt compelled to introduce the term 

 McElmo for rocks of nearly the same 

 age as the Morrison, and the term La 

 Plata for a massive white underlying 

 sandstone. The La Plata sandstone 

 should perhaps be included in the Gun- 

 nison. Recent work has extendetl the 

 names McElmo and La Plata north- 

 west to Greenriver, Utah. 



In spite of this confusion it seems 

 best here to use the three terms, so the 

 name McElmo is applied on sheets 7 

 and 8, although Gunnison was used oa 

 Sheet 6 for rocks of about the same age. 

 The reader should therefore remember 

 that the Morrison, Gunnison, and Mc- 

 Elmo include rocks that may be equiva- 

 lent in age. 



