80 



GUIDEBOOK OF. THE WESTERN UXITED STATES, 



coarse red conglomerate tliat is seen to best advantage toward the 

 right (north). These ridges were formed by mountain-making move- 

 ments which fractured the once horizontal layers and shoved them 

 up to a vertical position, and by erosion, which carved them into 

 the present forms. 



■m 



Beyond this series of sharp ridges and well exposed in the gorge^ on 



about 1,100 feet thick. 



formation 



format 



: numbers of fossil si 

 'go in the Beckwith 



Knight. 



Elevation 7,043 feet. 

 Omaha 916 miles. 



A.sp 



crops out. Still farther west the route again enters 

 an area occupied by the red beds of the Wasatch 



group 



Knight 



Wasatch of this reg: 



from Knight station. 



& 



About 2 miles west of the station the train reaches the open valley 

 of Bear River, a broad marshy flood plain over which the river 

 meanders in a serpentine course and which at times of hicrh water is 



com 



Benr River rises in the Uinta Mountains, about 

 50 nules to the south, and flows in a circuitous route, first northwest- 

 ward and then westward, around the north end of the Wasatch 

 Mountains, and finally doubles back upon itself in a general southerly 

 coui-se and empties into Great Salt Lake. Measurements of its flow 

 show that on the average 375 cubic feet of water passed Evanston 



every second in 1914. 



current is swift in some places, and 



from this point in its course to its mouth 



feet. Water from Bear River and its tributaries is utihzed 

 gating about 75,000 acres of land. 



consists 



dark sliale, some of it carbonaceous, and 



im 



and in some places it includes beds of coal . 

 It may be distinguished from the older, 

 .unfossiliferous Beckwith beds by its 

 darker color and by the fossils near its 

 base. 



Some parts of the formation contain 

 numerous fossil plants, as w^ell as shells of 

 fresh^water and brackish-water mollusks, 

 unlike those found in Cretaceous beds 



elsewhere. 



formation 



distributed, being known only from Bear 

 River City— an early construction camp 

 of the Union Pacific near Bear River on 

 the line now abandoned — northward to 



the Salt 



River Range. 



Its thickness 

 000 feet. 



The Bear River beds were formed not 

 far from the continental land mass that 

 remained above water throughout Upper 

 Cretaceous time, west of the interior sea, 

 and it probably represents a delta at the 

 mouth of a river that drained this old con- 

 tinent. The presence of fossil plants, coal 

 beds, and fresh-water invertebrates in the 

 Bear River formation, together with its 

 stratigraphic position beneath the Aspen 

 formation, which ia known from fc^ils 

 contained in it to be of Benton (Upper 

 Cretaceous) age, has led to the somewhat 

 persistent suggestion that the Bear River 

 maybe the time equivalent of the Da- 

 kota sandstone, although its maximum 

 thickness is about 50 times that- of the 

 Dakota, 



