SOUTHERN PACIFIC LINES 269 
the early part of the uplift of the San Bernardino Mountains. It is 
probable that at the same time the San Bernardino Valley subsided 
somewhat, so that its rock floor, sheeted over by silt and sand, stood 
at a lower level than at present. Streams cut deep canyons in the 
mountains and carried boulders, rocks, and clay out over the plain 
until many hundreds of feet of alluvial material was accumulated. 
(Mendenhall. ) 
On approaching El Casco siding there is in view a steep-sided gully 
cut in the relatively level valley floor of fill, showing that there have 
been two stages of valley development—an earlier one, followed by 
some deposition, and the present one of invasion by a stream cutting 
rapidly to a lower grade. 
A few miles farther down grade San Timoteo Canyon opens into 
the eastern part of the San Bernardino Valley, which is traversed 
by the Santa Ana River, a large stream draining an area of con- 
siderable extent in the San Bernardino Mountains and used exten- 
sively for irrigation. Probably no other stream of its size in the 
United States is made to serve more varied uses. In its course of 
not more than 100 miles from the headwaters to the ocean the same 
water is used at least seven times for power and irrigation, by means 
‘of artificial storage, diversion into canals, and recovery of seepage 
water by pumping.® 
The railroad passes through Redlands station 3 miles south of the 
fine city of Redlands, which is noted forits oranges (see pl. 42, B) 
Sopa and for the beauty of its environment. A park in- 
: cluding Smiley Heights, with a notable collection of 
Elevation 1,350 feet. . 3 
opulation 14,177. fine trees, offers some spectacular drives with charm- 
eans 1,94 ing views of great orchards and vistas of the stately 
San Bernardino Mountains, their higher peaks capped 
by snow for a large part of the year. (See pl. 44, A.) Six miles 
northeast of Redlands is the deep canyon of the Santa Ana River, 
which is followed by a road that gives access to some of the many 
resorts in the higher parts of the San Bernardino Mountains. Near 
by are the Urbita Hot Springs, with a | swimming pool and 
sulphur and mud baths. The Redlands district is at the eastern 
margin of the great orange belt of southern California. The soil is 
favorable, being a porous sandy loam that keeps free from alkali 
under irrigation, and much of the land is sufficiently high to be safe 
from frost, which occasionally occurs in the lower part of the valleys 
on chilly mornings. Water for irrigation is both pumped from the 
large underflow from the Santa Ana Wash and diverted from the 
Santa Ana River and Mill Creek. 
8% See U, S. Geol. Survey Water-Supply Paper 636, pp. 176-177, 1930, 
miles. 
