DENVER & RIO GRANDE WESTERN ROUTE. 183 
grade. Within a short distance it rises above the grade, and below it 
may be seen a dark shale. This shale also rises downstream, and at 
milepost 388 the top of a brick-red massive sandstone (Triassic) 
appears beneath it on the opposite side of the valley. Wherever it is 
exposed this sandstone, on account of its deep and uniform color and 
its massiveness, is the dominating feature of the canyon. As the 
rocks dip toward the northeast (see Pl. LXXVI, A) and as the 
general course of the stream and of the railroad is toward the north- 
west, the rocks exposed on the two sides of the canyon are not neces- 
sarily the same. Even if the stream followed a straight course the 
beds at the same level on its opposite sides in the same stretch would 
be different, but the difference is greatly exaggerated because the 
stream swings from side to side in great meanders. At many places 
a point on the outermost part of a bend to the left is more than a 
mile from the outermost part of the next bend to the right. The 
farther the stream swings to the left the lower or older are the rocks 
in the canyon walls, and the farther it swings in the opposite direc- 
tion the higher or younger are the rocks in the walls. 
Wherever the brick-red sandstone rises 100 feet or more above the 
water there is an inner box canyon with vertical walls, but where 
this sandstone is below the water the canyon walls recede by slopes 
and terraces. This compound character of the canyon is shown in 
Plate LXXVI, A. At milepost 400, 2 miles beyond Bridgeport sid- 
ing, the railroad enters a tunnel that is excavated entirely in the mas- 
Sive brick-red sandstone, which is ideal material in which to drive 
a tunnel, for the roof needs no timber to support it, and the portals 
are equally durable. This tunnel is 2,256 feet long—nearly half 
a mile. ; 
In places the walls of the canyon are about 500 feet high, but they 
lack both the ruggedness and the regularity that characterize the 
other great canyons on this route. Finally they begin to decrease in 
height, until, half a mile beyond milepost 410, the traveler begins to 
see open country, and soon he finds himself back in the same shale 
valley that he left a few miles below Delta. A mile farther along 
the train reaches the station in the small village 
Whitewater. of Whitewater. Here Grand erect looms up og 
Elevation 4,665 feet. the right as the most conspicuous feature in the 
pe hdieage On leaving Whitewater the railroad 
again enters the canyon, which, however, 1s no- 
where so deep nor so interesting as it is farther up. Its walls om 
composed entirely of rocks of the Gunnison formation, or of rock 
i above it, and at no place does the brick-red sandstone again 
make its appearance. The river meanders broadly, swinging first 
to one side and then, to the other in sharp curves which make the 
