iSdS.] j^yi [lliiydcn. 



I'otween the well marked Cretaeeons beds and the meta- 

 raorphic rocks nearly all the rocks are l)rick-rcd, or tinged more 

 or less with red from the presence of tiie peroxide of iron, and 

 diffused through them there is a certain amount of gypsum ; 

 hence they have been called gypsifcrous deposits. In the Black 

 Hills, Big Horn and \\'in(l River Mountains these red beds are 

 largely developed, and there they contain beds of beautiful white 

 amorphous gypsum, varying in thickness from five to sixty feet. 

 Along the east slope of Pike's Peak in Colorado these forma- 

 tions contain valuable beds of gypsum, but in the Laramie 

 Plains I have as yet observed no regular beds. The thickness 

 of these deposits was estimated by Prof. Hall to be about 3000 

 feet, while the Cretaceous beds were 500 to 800 feet thick. 



Camping with our wagons at the base of the main range of 

 mountains near the source of the Little Laramie, we prepared 

 to ascend the mountains on horse-back to the gold mines ; the 

 distance was about ten miles before we came in view of the 

 " diggings," and to reach them made an ascent of about 2000 

 feet above the bed of the creek. We were then between 10,000 

 and 11,000 feet above the sea, very near the elevation of per- 

 ])etual snow and where frost occurs every night of the year. 

 On the summits of these lofty mountains are some most beauti- 

 ful open spots without a tree, and covered with grass and flow- 

 ers. After passing through dense pine forests for nearly ten 

 miles, we suddenh^ emerged into one of these park-like areas. 

 Just in the edge of the forest which skirted it were banks of 

 snow six feet deep, compact like a glacier, and within a few feet 

 were multitudes of flowers, and even the common wild straw- 

 berry seemed to flourish. These mountains are full of little 

 streams of the purest water, and for six months of the 3'ear 

 good pasturage for stock could be found. 



The gold is sought after in the gulches that are formed by the 

 little streams that flow from the Medicine Bow and other snowy 

 mountains, most of which flow into the North Platte. We 

 labored for two daj^s to discover the quartz seams which, we 

 supposed to be the source of the straj^ lumps of gold, but the 

 great thickness of superficial drift which covers all these moun- 

 tains, concealed them from our view. The gold as far as known 

 in this district seems to be confined to the lower glacial drift. 

 That valuable mines will be found in these mountains at no dis- 

 tant day seems ver}- probable. The geological evidence is quite 

 conclusive, and the mountains are a continuation northward of 



