GEOLOGICAL SURVEY OF THE TERRITORIES. 17 



also masses of sandstone which appear like mud-rock, and layers like 

 impure white limestone, probably composed largely of sulphate of lime 

 and magnesia. From our camp on the Laramie we enjoyed one of the 

 beautiful sunsets which are not uncommon in this western country. 

 But this was a rare occasion, for the sun passed down directly behind 

 the summit of Laramie Peak. The whole range was gilded with a 

 golden light, and the haziness of the atmosphere gave to the whole 

 scene a deeper beauty. Such a scene as this could occur but once in a 

 lifetime. From Laramie Biver to the Bitter Cottonwood our road 

 extends over broad, grassy plains, entirely underlaid by the recent ter- 

 tiary beds. Upon our left the mountains are in full view, and the grassy 

 plains seem to extend to the granite foot-hills. As the Bitter Cottonwood 

 Creek seemed to be the nearest point to the Laramie Peak, we camped 

 here two days to make an examination of that region. On the morning 

 of August 12th I started for Laramie Peak with Messrs. Gifford, Jack- 

 son, Elliot, Turnbull, and Ford; passed up the valley of the Cottonwood 

 to the foot-hills of the mountains. Mr. Jackson made a large number 

 of excellent photographic views, which will prove of interest not only 

 to science but also to all lovers of " the picturesque in nature." The 

 scenery in this region is very attractive as well as instructive. The 

 valley of the Bitter Cottonwood, as well as the numerous little ravines 

 that flow into it, are inclosed by rather high bluff-like banks, which 

 show no rocks older than the White Biver tertiary, until we reach the 

 base of the mountains. Still there is a great thickness of what we have 

 called "local drift," which increases to the base of the mountains, 

 and to a great extent conceals all other rocks. This superficial drift 

 becomes coarser and the stray rocks less wofn the higher we ascend. 

 The difference in elevation between our camp on the Cottonwood, and 

 the base of Laramie Peak — a distance of twenty-five miles — is about 

 one thousand eight hundred feet. I have previously noticed the enor- 

 mous development of the sedimentary ridges north of the Chugwater, 

 and the flexure of the mountains around to the north and northwest ; 

 also, the dying out of the ridges in the plains one after the other in the 

 usual en echelon manner. Between Laramie Caiion and Horseshoe Creek 

 these ridges are not seen at all, rising above the surrounding country, 

 and they are exposed only in one locality, to a limited extent, by one of 

 the branches of the Cottonwood, cutting a deep valley through the 

 superficial drift and tertiary beds, just at the base of the mountains. 

 The red beds and carboniferous limestones only, are seen on each side of 

 the road which leads from Fort Laramie to Laramie Peak. Here are two 

 small rounded hills capped with carboniferous limestones. Still, for the 

 most part, the drift and tertiary beds jut up against the granite foot-hills, 

 and the long, table-like benches extend down for miles with a gradual 

 but rather rapid descent, giving a far-extended but beautiful and pic- 

 turesque appearance to the scene. 



Between the Chugwater and the Laramie Biver the surface seems to 

 have escaped erosion to a great extent, while between Laramie Biver 

 and the Bitter Cottonwood Creek the erosion has been tremendous. 

 All the ridges, which must have been from five hundred to one thousand 

 feet in height, have been smoothed clown and concealed, and the gueiss 

 and granites which form the foot-hills or lower ranges have been worn 

 away so that they project but little above the surface. We have there- 

 fore a belt of country underlaid by metamorphic rocks, five to ten 

 miles in width, covered with most excellent grass, as level as the plains, 

 and very desirable for settlement j which, but for erosion, would have 

 been as rugged as any portion of the mountainous district. As we 

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