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GUIDEBOOK OF THE WESTERN UNITED STATES. 



parallel with them. The men were eag^er to climb the mountains, 

 explore their wonderful peaks and valleys, and see the country that 

 lay beyond, but a few days of hard climbing up the rocky slopes 

 satisfied them that they could not reach the siunmit of the range 

 in a short time and that mountain climbing was not so easy as it 

 appeared from a distance; so they were content to proceed south- 

 ward along nearly the route that is now followed by the Denver & 

 Eio Grande Western Railroad. The entrance to the canyon may be 

 seen from the train, but, owing to its many bends, the canyon does 

 not appear to be an open cut through the mountain front. 



In many places at the foot of the mountains the steeply dipping 

 sandstone forms sharp hogbacks, which may be seen from the mov- 

 ing train, and, as the sandstone is mostly red, the traveler will soon 

 learn to associate red sandstone and hogbacks with the foothills of 

 the mountain front. These beds are very prominent near the mouth 

 of Pliun Creek and may be seen to good advantage from milepost 17, 

 about 11 miles up the creek. 



The scenery of the lower part of the valley of Plum Creek is 

 smooth and uninteresting. The surface is a rolling upland, which 

 can not be irrigated from the South Platte because it lies too high 

 above that river, and it consequently appears rather barren to those 

 who are accustomed to a more humid climate. The only railroad 

 station in this part of the valley is Louviers, which is merely a ship- 

 ping point for the DuPont Powder Co., whose plant for the manu- 

 facture of high explosives is on the west (right) of the track. 



Above Louviers Plum Creek swings eastward, and it is bordered 

 on its east side by bluffs and mesas of white sandstone." Although 



^" All the rock seen near the railroad 

 track from Denver to a point beyond 

 Palmer Lake is composed of fragments 

 derived from the decomposition of the 

 granite and gneiss of the mountains. 

 This material, which consists mostly 

 of quartz and feldspar, is known to 

 geologists as arkose. The formation 

 is called the Dawson arkose, and it is 

 of the same geologic age as the forma- 

 tions about Denver that have been 

 called the Denver and Arapahoe for- 

 mations. Richardson, in the Castle 

 Rock folio (No. 198) of the Geologic 

 Atlas of the United States, describes 

 the rock as follows : 



"The Dawson arkose, derived from 

 the Pikes Peak granite and associated 

 rocks, was laid dowTi under various 

 continental conditions, chiefly as wash 

 and fluviatile [stream] deposits accom- 



panied by local ponding. During the 

 accumulation of the arkose tliis region 

 may be conceived of as a piedmont 

 [foot of the mountain] area having a 

 moist and temperate climate, an area 

 in which the vegetation was character- 

 ized by the presence of many fig trees, 

 palms, magnolias, poplars, willows, 

 oaks, maples, etc., and which was occu- 

 pied by Triceratops (huge three- 

 homed dinosaurs), crocodiles, turtles, 

 and other reptiles and by primitive 

 mammals." 



In other words, the material derived 

 from the mountains was carried out on 

 a nearly flat surface and deposited by 

 the streams in mucli the same way as 

 the streams of to-day are carrying the 

 waste of the mountain I'ocks and 

 spreading it over the low parts of the 

 plains. 



