18(59.] '-'-'- . [Haj'don. 



of the Laramie river. Altliougli covered thickly with l)oulders the soil 

 is good, and the grass excellent. It has been for years a favorite pasture 

 ground. 



Elk mountain is a short range of spurs with its highest point fronting 

 the creek ; it resembles the short range, with abrupt front, east of the 

 Little Laramie. The metamorphic rocks have been uplifted, while the 

 unchanged rocks have remained quiet, or been let down at the foot of 

 the mountain, without leaving that series of upheaved ridges which we 

 find running along the base of most of the mountains. The range is 

 about 10 miles long, forming what I have called an abrupt anticlinal; 

 that is, on one side of the mountain the anticlinal is complete, the un- 

 changed rocks inclining /r(9?« the mountain in regular order of sequence; 

 while on the mountain side the rocks are nearly vertical, and the sedi- 

 mentary beds jut up against the base, their edges being entirely con- 

 cealed. Against the north side of Elk moimtain the cretaceous and 

 some of the tertiary beds jut so abruptly that all the older rocks are 

 concealed, while on the opposite side, the entire series, from the granite 

 nucleus to the cretaceous formation, may be measured across their up- 

 turned edges. 



Along the immediate base of the mountains there is a belt of country 

 which in many instances might be called a monoclinal valley. It has 

 been even nrore smoothed by erosion than any of the valleys of the 

 streams, and always runs at right angles to them. Through this 

 valley of erosion the old stage road and Western Union Telegraph line 

 is located. 



North of the road can be seen a series of upheaved ridges somewhat 

 irregular in their continuity but gradually receding northward like sea 

 waves. The first ridge is composed of a series of dark brown indurated 

 clays and sands, with layers of more or less laminated rusty sandstone of 

 fine texture, and tendency to concretionary forms, varying rapidly in 

 thickness from 2 to TO or 12 feet, dipping N". 20" W. from 5° to 10^ 20° 

 west of north. In this ridge are quite extensive beds of lignite, one of 

 which is about six feet thick separated into three jjarts by layers of clay. 

 In the harder layers above and below are great quantities of indistinct 

 vegetable impressions. The interval between the first main ridge and 

 the second is about 1^ miles, and in that interval several lignite beds 

 crop out with layers of light gray fine graiiied siliceous rock. 



The second main ridge is composed of a variety of beds inclining 3° to 

 5°, the general color being brown, or light drab, while the harder layers 

 are rusty sandstones. One bed, perhaps 50 feet thick, is of fine gray 

 indurated sand with a gTcenish tinge. At the summit of this ridge were 

 very distinct indications of the lignite bed at some period iii the past. 

 Several feet of rocks were baked f,o a brick red, color, and fragments of 

 completely fused rock lay scattered about. From the bed of the Medi- 

 cine Bow to the summit of the second ridge I estimated that 1200 to 1500 

 feet of strata were exposed to view, and from the presence of lignite and 

 deciduous leaves I regarded them all as belonging to the tertiary series. 

 Some of the sandstones are inade up of an aggi^egate of crystals of 



