38 ■ SURVEY OF COLORADO AND KEW MEXICO. 



nearly liorizontal, altliongli not more than ten miles in a straight line 

 from the metamorpliic rocks. The whole prairie country has been so 

 planed off that it is finely and gently rolling, and the drainage is excel- 

 lent. The streams which flow from the sides of the mountains are fed 

 by perpetual springs, and are consequently persistent and nniform in 

 their amount of water, affording the best water-i)ower in the coimtry. 



From the soda lakes to the great "divide" the cretaceous and tertiary 

 beds, outside of the No. 1 sandstone ridge, are smoothed down and 

 grassed over so that they are not conspicuous, though there are exi:)os^ 

 ures enough to guide the geologist. They are so concealed by suijerfl- 

 cial gravel and sand that they ijresent no good sections either to show 

 the strata or dip. This regularity of the surface renders the Platte 

 Valley, as well as those of its branches, remarkably fine for farming 

 and grazing, and vast herds of cattle already cover the grassy hills and 

 l)lains. The terraces and benches which extend down from the foot of 

 the mountains are well shown. 



Along the Platte River, near the canon, a coal bed was opened at one 

 time, but now it is covered with loose material which has fallen from . 

 above, so that it is entirely concealed. The strata here are nearly ver- 

 tical. There are two beds of coal, in all about five feet thick, separated 

 by about two feet of clay. The coal is not very good, and has not been 

 used for three years. It is probably the same bed seen at Golden City, 

 thinning out southward. 



Along the Platte and Plum Creeks, the streams cut heavy beds of 

 boulder gravel and fiue sand, and it is under this deposit the coal is 

 found. The valleys of the South Platte, and its branches, between Den- 

 ver and the mountains, are exceedingly fertile and productive, and at 

 this time they are covered with splendid crops. Nearly or quite all of the 

 available bottom lands are already taken up by actual settlers, and are 

 under cultivation. The present season has been unusually favorable for 

 farming throughout the Avest. 



The plain country south of Denver comes close u^) to the foot of the 

 mountains, so that the belt of upheaved sedimentary rocks grows nar- 

 rower and narrower until, a few miles south of the Platte caiion, they 

 cease entirely for a time. The ridges are very high, ranging from four 

 hundred to six hundred feet above the bed of the Platte. To the south- 

 west can be seen, rising like a range of mountains, the high "divide" 

 between the waters of the South Platte and Arkansas Elvers, covered 

 quite thickly with pines. 



The first main ridge contains a few layers of No. 2; alternations of 

 clay and sand passing down into the sandstones of No. 1. This ridge 

 is quite massive and inclines 43°. In the channel of the South Platte, 

 the distance from the outside of the ridge containing the sandstones of 

 No. 1 to the metamorphic rocks, is not more than half a mile. From 

 this point to the "divide" the ridges are split np and much crowded. 

 The reddish and variegated sands are worn, by atmospheric agencies, into 

 the most wonderful and unique forms, equal to the " Garden of the 

 Gods," only on a much smaller scale. Here also the red and variegated 

 sandstones jut up against the metamorphic rocks as if the continuity 

 was unbroken. Indeed, the apparent conformity is complete. 



The hills of the first range, composed of metamorphic rocks, are curi- 

 ously rounded and grassed over, and are made up of a reddish, decom- 

 posing granite. But, as we ascend, these peaks or rounded cones become 

 sharper, the sides more rugged, and the rocks more comx)act. 



As we go southward the indications of beds of Jurassic age become 

 more and more feeble. Under the massive sandstones of No. 1 are a 



