GEOLOGICAL SURVEY OF THE TERRITORIES. 147 



Some of these gems are very beautiful, and the sprangles or dentritic 

 delineations are wonderfully like the stems of moss, and it is quite dif- 

 ficult for most travelers to believe that they are not actually plants im- 

 prisoned in the flinty mass. Most of the agates are of little value, but 

 occasionally one is found of great beauty that will sell for $50 or $75. 

 They are also found in the Middle and South Parks to some extent ; 

 those in the Middle Park being regarded as by far the best. Beautiful 

 specimens of opal, semi-opal, or opaline, occur, and when found are 

 especially attractive. A variety of opal of a milky- white color, and very 

 transparent, was found in a lode of gold-bearing quartz, near Idaho, 

 Colorado, and was much sought after for a time. 



CHAPTER XII. 



BEAR RIVER TO GREAT SALT LAKE VALLEY. 



For more than two. hundred miles we have passed over what appears 

 to be one of the most desolate regions of the West. Even the most enthu- 

 siastic of our companions in travel will not hesitate to pronounce it a 

 desert. Yet a careful analysis of the soil will show that it possesses the ele- 

 ments of fertility. If streams of water could be made to circulate through 

 these broad, treeless, and almost plantless plains, and the same amount 

 of human industry employed as has been so remarkably exhibited by 

 the Mormons in Salt Lake Valley, there is no doubt they would become 

 productive. Whether in the great future this state of things can be 

 brought about by artesian wells and cheap labor is a question for the 

 people of that future to determine. It is my duty simply to present the 

 facts as I read them. As we proceed westward from Fort Bridger, we 

 note at once the favorable change that takes place in the aspect of the 

 country and of the vegetation. Broad plains and sloping hills, crowded 

 thickly with grass, with an almost entire absence of the wild sage, are 

 now the rule. Patches of the quaking asp appear here and there, and 

 along the streams are fringes of the Cottonwood. 



Soon after leaving Carter Station, toward the west, the pinkish beds 

 come in suddenly. They seem to rise from beneath the Bridger Group. 

 Their dip is about northeast 3° to 5°, and they have evidently been dis- 

 turbed slightly by the later movements which elevated the Uinta range. 

 This series of strata, to which I have given the provisional name of the 

 Wasatch Group, are composed of red, indurated, arenaceous clays, with 

 beds of grayish and reddish gray sandstones alternating. Pinkish and 

 purplish clays are the dominant features, and give the lithological charac- 

 ter to the groups as far west as Echo Canon, when the conglomerates pre- 

 vail. The latter group is full of beds of sandstone, largely concretionary, 

 but the sandstones or harder layers are seldom of a reddish color. Be- 

 fore reaching Bridger Station the strata on either side of the road are 

 horizontal, or nearly so. A long flat ridge extends down a little east of 

 north from the Uinta Mountains, between Black's Fork and the Muddy. 

 This may be regarded as the geological divide between the waters of 

 the Great Salt Lake Basin and the drainage of Green River. The 

 Muddy is one of the branches of Black's Fork, which flows into Green 

 River, and west of this stream we have what is called the eastern rim 

 of the Great Basin of Salt Lake. If we were to travel southward to 

 the foot of the Uinta Mountains from the railroad along this divide, we 

 should be able to detect no well-marked line of separation between the 



