12 GUIDEBOOK OF THE WESTERN UNITED STATES. 
around and double back upon itself, thus zigzagging its way up the 
mountain slope. The train climbs steadily upward, and one by one 
the ridges that from below seemed to be of great height are sur- 
mounted and they are found to be only low spurs of the still higher 
mountains above. 
As the train nears the summit and encircles the little pond called 
Yankee Doodle Lake, the traveler may see some of the effects, other 
than the rounding of valleys, that the old glaciers have produced on 
the mountain scenery. In the canyons below, where the ice moved 
down in a great stream from the heights above, its effect was to 
smooth and round the slopes and to do away with much of the 
ruggedness that must have marked these canyons before they were 
occupied by the ice. Near the summit the ice scooped out in the side 
of the mountain great amphitheaters, called cirques, making the 
tops much more rugged than they were before. The circular depres- 
sion that holds Yankee Doodle Lake is such a cirque, and all the vast 
rock slopes above the lake have been steepened by undercutting by 
the ice. Other cirques (such as those shown in Pl. V) may be seen 
in the mountains; indeed, the entire front above this place, up which 
_ the railroad finds its way to the summit, consists of the walls of 
cirques that have united. The steepness of this slope is due almost 
entirely to the action of ice. In places the road is constructed along 
the upper edge of one of these great cirque walls, and the traveler 
may look down on the right nearly 1,000 feet into the cirque below. 
Although the cliff has an appreciable slope, it appears to be vertical 
-especially when viewed from the moving train. 
At last the traveler reaches the summit, at Corona, 11,680 feet 
above the level of the sea, but the great aoniiaada through which the 
train passes have prevented him from getting a fair view of the 
mountain summit. As soon as the train stops at Corona he may pass 
from the confinement of the snowshed and enjoy to the utmost the 
boundless space of the mountain top. On the crest in any direction 
there are peaks higher than Corona, the most prominent being James 
Peak (13,260 feet) on the south and Longs Peak (14,255 feet) on the 
north, but they can be seen from only a few points. On the west 
the traveler can look down on the billowy surface of Middle Park, 
one of the surface basins in the midst of the mountains; and on the 
east he can look over the wide expanse of spur and ravine up which 
the train has so laboriously clim 
The railroad beyond Corona descends the fairly smooth western 
slope of the Front Range by many loops and turns until it reaches 
the floor of Middle Park. It crosses this immense basin in the heart 
of the mountains, cuts through the Gore or Park Range beyond in a 
deep, rugged canyon, and then continues westward across the great 
plateau country of northwestern Colorado. The plateau contains 
