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GUIDEBOOK OF THE WESTERTiT UNITED STATES. 



The railroad cut at the summit of the pass is in a volcanic breccia 

 made up of bombs and other fragments thrown out by a volcano and 

 afterward consolidated and cemented into a bed of rock. The source 

 of this volcanic material is not known, but it probably came from the 

 south, where the eruptions were many and violent, though they did 

 not extend into this region. This breccia is much younger than the 

 rocks of Ouray Peak, and it therefore does not indicate that that 

 mountain is a volcano. 



The steepest railroad grade on the east side of the summit is 4 per 

 cent, or 211 feet to the mile, a grade that is maintained from a point 

 not far above Mears Junction to the summit, a distance of 14 miles. 

 The grade on the west side is the same from the summit of the pass 

 to a point about a mile below Chester, a distance of 9 miles. As the 

 maximum grade on the standard-gage main line is only 3 per cent, 

 or 158 feet to the mile, a change in gage here would probably mean 

 an entirely new location, so as to avoid the steep grades and short 

 curves. 



On emerging from the snowsheds at the summit the traveler has 

 spread before him on the left the long slope down which the rail- 

 road winds with many loops and turns. This side of the mountain 

 is more nearly treeless than the east side, because it is much drier, for 

 it is swept by dry winds that have passed over the arid plateaus of 

 southern Utah and Arizona. There are no indications that glaciers 

 ever existed on this side, for the entire slope is exposed to view and 

 nothing resembling a terminal moraine can be seen. This fact also 

 is due to the strong west winds and the drier atmosphere on the west 

 side and to the greater heat of the sun's rays, which aided the melting 

 of the snow on the south and west sides. After the train loops back 

 directly under the pass there is little of interest to be seen ; the slopes 

 are generally smooth, and the valley is without scenic attractions. 



A short distance west of Marshall Pass the railroad goes from 

 volcanic breccia to granite and then onto quartzite and shale similar 

 to those seen below the Ouray or Leadville limestone in both Eagle 

 River canyon and the canyon of Colorado River above Glenwood 

 Springs. These rocks are not strikingly exposed and probably will 

 be detected only by those who look specially for them. 



from a toothache! Such a trip would 

 be bad enough to make under present 

 conditions, but what must it have been 

 through an unbroken wilderness and 

 across the backbone of the continent! 



Truly the " winning of the West " 

 called for courage and endurance of 

 which the traveler of to-day, with all 

 the comforts and even luxuries of 

 travel, can have little comprehension. 



