a i 
DENVER & RIO GRANDE WESTERN ROUTE. 25 
but a short distance from the upturned rocks along the mountain 
front, these sandstones lie practically horizontal, 
a fact which indicates that they are near the middle 
paerstion: sei feet. of the great downfold of the rocks east of the 
e Front Range. Figure 6 represents the edges of 
the upturned rock beds as they would appear if they had been cut by 
a giant knife at right angles to the trend of the mountain range. 
The Atchison, Topeka & Santa Fe Railway, which has been on the 
east (left) side of the train since it left Denver, passes over the Denver 
& Rio Grande Western Railroad at the town_ of 
Sedalia. Sedalia. The upland on the east is here nearer the 
Elevation 5,835 feet. track than it is farther north, and it stands out as 
Denver sen. @ plateau with a steep or even vertical front. Some 
of these steep slopes are merely projecting points of 
the highland, but others are parts of hills that have been isolated from 
Louviers. 
DANO R GW 
mie formation 
Montana group 
Os Colorado group 
2. Purgatoire and Morrison 
4000 6000 Feet 
acs ab aca sche 
Figure 6,—Section at mouth of Platte Canyon. 
it by the cutting of the streams. Such isolated remnants of a once ex- 
tensive plateau are very conspicuous on the west (right) of the road. 
A hill of this kind in the East would not be called by any special name, 
but in the West, and especially in the Southwest, a flat-topped hill is 
almost universally called by the Spanish name mesa, meaning table. 
Near Sedalia are the forks of Plum Creek, one of which comes from 
the south and the other from the east. The one that comes from the 
south offers the more direct course for the railroad, but the one that 
comes from the east is the longer and has the better grade, so it was 
selected, even though its course is more roundabout. | 
The most prominent of the mesas is Castle Rock, which may be seen 
far ahead on the right soon after the train passes When 
first seen it is so far away that it seems to be only a small hill, but 
as the train proceeds it becomes more conspicuous, until ata siding 
called Plateau it appears on the right as a very prominent conical 
