134 



GUIDEBOOK OF THE WESTERN UNITED STATES. 



a photograph taken at tliis point, looking downstream. The first 

 tunnel near milepost 350 is cut in the massive granite, which con- 

 tinues to rise higher and higher in the canyon as the train proceeds. 

 The part of the canyon in which the base of the quartzite is only 

 a few score or few hundred feet above water level is its most inter- 

 esting and picturesque part, which is all too soon passed by the 

 trains. The canyon walls are nearly vertical, and the cliffs formed of 

 the quartzite stand up like immense architectural structures an*! 

 present great variety of form and color. The joints, which cut the 

 rocks in at least two directions, give rise to smooth vertical faces of 

 rock and to buttresses and minarets almost without number. The 

 canyon here is narrow and tortuous, and many magnificent vistas 

 can be had of the swiftly flowing river and the dark walls, which 

 even at midday seem to envelop the deeper parts with a somber haze. 

 From this apparentlj^ interminable narrow labyrinth the traveler 

 at length emerges into a more open part of the canyon, where he 

 may well be surprised to find dwelling houses and the station of 

 Shoshone. (See sheet 5, p. 150.) Here is the intake of the great 

 hydroelectric plant of the Colorado Power Co., whose transmission 

 lines the traveler may have seen near LeadviUe and near Idaho 

 Springs, west of Denver. The river is dammed at 

 the small railroac} tunnel just below Shoshone, and 

 the water is carried through a tunnel cut in the solid 

 rock to the power plant, which is 3^ miles farther 

 down the canyon.*^ The traveler may not realize the quantity of 

 water carried in this tunnel, but if he is making his journey in 

 summer he is soon aware that practically all the water of the river 

 has disappeared into the open mouth of the tunnel. 



The general attitude of the rock beds in this canyon and the adja- 

 cent plateaus on the north and south is shown in figure 34, which rep- 

 resents them as they would appear in a deep trench cut across the 

 canyon at Shoshone. The beds dip to the south, and the LeadviUe 

 limestone forms the surface of much of the plateau on the north, 

 but the limestones and sandstones on the south are covered by a great 



Shoshone. 



Elevation 6,119 feet 

 Denver 350 miles. 



^'In the cauyou near Shoshone the 

 Colorado Power Co. has built a large 

 plant for generating electricity by wa- 

 ter power — a hydroelectric plant. By 

 means of a diversion dam built just 

 below the station the water of Colo- 

 rado River is turned into a large con- 

 crete-lined tunnel, which carries it 

 along the north wall of the canyon 

 for 3* miles. When flowing at its full 

 capacity this tunnel will deliver 1,250 

 cubic feet of water every second to im- 



mense steel tubes called penstocks, 

 into which it is dropped to river level, 

 175 feet below. In its fall it drives 

 two large turbine wheels with a total 

 capacitj' of 18,000 horsepower, which 

 in turn drive generators of 14,000 

 horsepower. The electric current is 

 transmitted at a voltage of 100,000 

 through wires carried on high steel 

 towers for a distance of 180 miles to 

 Denver and is used also at several in- 

 termediate points. 



