32 Southern Valley Loams. 
“sand hill.’ All are distinctly calcareous. Even in the case of 
the latter, which is the lightest and is made of almost ninety per 
cent of inert sand, it is so deep and has its plant food in such 
highly available condition that it is producing very large crops 
of fruits where there is no rise of the bottom water to prevent 
root penetration. In the foot-hills of the Sierra Nevada there 
are some loose loams of light color resulting from the decompo- 
sition of granite, but they are as a rule inferior to the red foot- 
hill soils, which are more clayey, and will be mentioned among 
the clay loams later. ; 
The soils prevailing in the valley of southern California, from 
Redlands at its head to Los Angeles at its opening out toward 
the sea, consist chiefly of granitic sand, which at some points 
on the slopes forms the soils exclusively, but everywhere con- 
stitutes a prominent ingredient of the valley and mesa lands. 
These mesa lands are conspicuous for their orange-red tint, and 
the red sandy loam of which they are composed, to depths vary- 
ing from ten to as much as eighty feet, is evidently the choice 
soil for orange culture. It is manifest that at some remote epoch 
it filled the entire valley. Of the middle portion much has been 
washed away, but islands of it form red-land tracts of greater or 
less extent all over the region, traversed by and more or less 
commingled with, the granitic wash from the valleys and cai- 
ons of the Sierra Madre. The latter frequently consists largely 
of gravel, and were it not for the luxuriant natural vegetation 
borne by these gravel beds, few would have thought of devoting 
them to the costly experiment of orange planting, which, never- 
theless, has proved eminently successful even on these unpromis- 
ing-looking masses of debris. In the upper valley (San Bernar- 
dino Valley proper) the red loam is conspicuous, and gives its 
name to the flourishing settlement of Redlands, on the terminal 
slope; but the heavy flow of water from the upper cafions, nota- 
bly from that of the Santa Ana River, has scoured it out of the 
valley itself, and left there, at least on the northern portion, gray 
and blackish granitic loams of great depth and productiveness, 
underlaid, and therefore underdrained, by the enormous gravel 
beds that hold the artesian water of this favored region. 
The reddish mesa soils prevail through the smaller southern 
California valleys as well, and are similar in character, as they 
are derived from similar geological formations. 
Where the surface descends gradually to the seashore, and 
not in bluffs, there are, as in Los Angeles and Orange Counties, 
coast flats several miles in width, where the soil is a dark-colored 
sandy loam, glistening with scales of mica, and more or less 
affected with alkali in the lower portions. Similar soils are 
found in tracts of greater or less extent up the coast as far as 
