168 GUIDEBOOK OF THE WESTERN UNITED STATES. 
east and the San Gabriel Range on the west, which affords an easy 
outlet into the great coastal plain or valley of southwestern California. 
It is 40 miles west to the next pass, and to the southeast of this gap 
mountains of considerable height extend for 200 miles continuously 
to Colorado River. Some of the most notable cuts, 60 feet deep, are 
near Dell siding, in one of which will be seen a remarkable framework 
several stories in height, designed to prevent the sand from washing 
and sliding into the cut. 
Toward Gish the principal material is moderately compact, light- 
colored massive sandstone with conglomeratic streaks. It contains 
many fragments of feldspar and quartz, evidently derived from 
anite 
Halfway between mileposts 64 and 65 the canyon narrows, turns 
south, and passes between steep ledges of hard, older rocks of the 
igneous and metamorphic series constituting the mountain ranges to 
the east and west.? 
The mountain slopes are covered with bushes in considerable 
variety, in great contrast to the sparse vegetation on the Mohave 
Desert. The difference is due to increased moisture on the ocean 
side of the mountains. 
Near milepost 69 the canyon of Cajon Creek widens into a valley 
bordered by mountainous slopes, but with a wide wash in its center 
and a broad sloping terrace at the foot of the mountains on the north 
side. This terrace is terminated by a steep slope or high bank at its 
foot, where Cajon Creek has cut into it, a feature which is con- 
spicuous for 2 or 3 miles. As the valley widens, however, the cut 
bank ends and the slope blends with the general plain, which rises 
gradually to the rocky ledges at the foot of the mountain, These 
terraces and slopes consist of sand and gravel washed down from the 
mountains and deposited at their foot. On the terrace are several 
ranches with orchards of considerable size. 
At Verdemont station the west wall of the canyon ceases as the 
mountain slope bears away to the west, and the railway is in the 
' Just west of Gish, along Cajon Creek, 
are many prominent ledges of this rock 
dipping to the northeast at an angle of 20° 
or more. As the valley of the stream is 
descended (on a southeast course) the 
ridges on each side show numerous out- 
crops of the lower beds of the sandstone 
series about Cajon siding, and for some 
distance beyond. In this vicinity the 
beds are more and more tilted up until 
they dip north, or away from the moun- 
tains, at an angle of about 30°. They are 
believed to be of Miocene age. The rail- 
way and the valley in this locality follow 
the line of the faults which cut across the 
range. 
* Southward from this place these rocks 
appear extensively in the rocky slopes of 
the valley and they are cut by the railway 
i principal 
places on the lower slopes of the valley 
there are remnants of narrow terrace de- 
posits of gravel and sand, notably in cuts 
just. beyond milepost 67, which is four- 
enthsofa +. 3 +. 1 L- ading 
+, 
