14 GUIDEBOOK OF THE WESTERN UNITED STATES. 



the mountain mass. In this valley is Golden, which for a time was 

 the Territorial capital. Here is the Colorado 'School of Mines, some 

 of the buildings of which may be seen on the left. Here are also 

 smelters and mills for reducing the ores mined farther up the creek. 



Immediately on leaving Golden the train plunges into the narrow, 

 tortuous canyon which Clear Creek has cut into the uplifted granite 

 mass. When boarding the train at Denver the traveler may have 

 wondered why this road was ever built narrow gage (3 feet), or, 

 even if so built, why it was not changed years ago to the standard 

 gage, but when he sees this canyon he no longer questions the wisdom 

 of the builders of the road in adopting the narrow gage nor that of 

 the management in retaining it. He soon realizes that only a single 

 narrow-gage line could have turned and twisted its way through 

 the canyon and that the change to standard gage would mean the 

 building of extensive tunnels and many bridges. The little narrow- 

 gage line, on the contrary, as shown in Plates VI and VII, winds 

 around every bend of the creek and every projecting spur of the 

 mountain and required almost no cutting of the solid rock. 



Although the canyon nearly everywhere has precij^itous walls, it 

 varies greatly in width. At some places, as shown in Plate VII, it is 

 merely a cleft sufficient to accommodate the stream that carved it ; at 

 others it is so broad that the stream has built flood plains upon which 

 the railroad has little difficulty in finding its way. The cutting power 

 of the stream has been nearly uniform throughout, but the resultant 

 form of the canyon depends largely upon the resisting power of the 

 rock through which it has been cut. Thus, where the granite is ex- 

 ceedingly massive — ^that is, without joints or fissures' of any kind to 

 weaken its resistance — the stream has not greatly widened its gorge, 

 but where the rocks are seamed with innumerable joints, or where 

 they have been so much squeezed as to form schists, the stream has 

 cut out a wide canyon. 



The rock in which the canyon is cut is generally called granite, 

 but some of it is banded and is properly called gneiss. (See foot- 

 note on pp. 9-10.) The bands of the gneiss show great contortions, 

 which are the result of movements in the rocky crust of the earth. 

 The gneiss is also seamed with dikes (rocky material that was once 

 melted in the earth's interior and forced into fissures of the rock) 

 and veins (mineral matter deposited from waters circulating through 

 fissures in the rock) of great variety of color and texture. In places 

 the rocks are nearly black with the mineral called hornblende; in 

 other places they are composed largely of white or pink feldspar or 

 are gray granites. 



At Forks Creek the canyon divides, and the railroad branch to the 

 right runs to Central City and Blackliawk, two of the most im- 

 portant and oldest gold-mining centers of Colorado. Central City 



