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 precipitous walls, it 
varies greatly in width. At some places, as shown in Plate VIT, it is 
merely a cleft sufficient to accommodate the stream that carved ‘ts at 
others it is so broad that the stream has built flood plains upon which 
the railroad has little difficulty in finding its way. Thecutting 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, ang the railroad branch to the 
right runs to Central City and Blackhawk, two of the most im- 
portant and oldest gold-mining centers of Colorado. Central City 
ip Rhee 
