276 GUIDEBOOK OF THE WESTERN UNITED STATES 
Six miles northwest of Ontario is the mouth of San Antonio Canyon, 
one of the larger drainage outlets from the San Gabriel Mountains, 
Geile: which furnishes considerable water for irrigation. On 
gioco the plain the creek bed spreads into half a dozen 
ulation 13,583. irregular ‘‘washes,’’ which are crossed by the railroad 
uf i iiaaans 1,963 near Ontario. From the gravel and sand under the 
lain a large amount of water is pumped for irrigation. 
The water is conveyed in canals lined with concrete and is distributed 
in underground pipes so as to prevent loss by leakage and evaporation. 
Ontario, with its companion settlements, North Ontario, San 
Antonio Heights, and Upland, extends widely across the salle slope 
and up the foothills of the mountains. The settlement is traversed 
by a handsome tree-shaded boulevard, Euclid Avenue, which runs 
north to the foot of the mountains. Ontario is surrounded by many 
orange and lemon groves and other products of irrigation, and one of 
its chief industries is a fruit-canning establishment, claimed to be the 
largest in the State. 
Pomona is a commercial, residential, and educational center, built 
on the western margin of the plain that extends from San Bernardino 
Pe to the San Jose and Puente Hills. Itis surrounded by 
omona. . « 
Elevation 886 fect,  °UenSIVe groves of oranges and other fruits and pro- 
ulation 20,804. duces large amounts of walnuts and grapes. About 
he Orleans 1,967 Pomona were grown the first oranges shipped from 
California. The underground water supply is utilized 
for irrigation by pumping from hundreds of wells. Much attention 
has been given to making the landscape lovely with trees and garden- 
ing. At Claremont, not far north, are the Claremont Colleges, one 
of the most beautiful and outstanding institutions of learning in the 
coast region, and the Greek Theater, which seats 4,000. 
Three miles west of Pomona the vailioad passes over a low divide 
between the San Jose and Puente Hills and descends the canyon of 
San Jose Creek. The San Jose Hills, to the north, consist mainly 
of a thick succession of shales and sandstones of the Puente formation 
(middle and upper Miocene). At their northeast end, 2 miles north- 
west of Pomona, there is granite * overlain by lava flows and volcanic 
tuffs and agglomerates at the base of the Tertiary section, 
similar succession on the south side of the railroad constitutes the 
ular flows, and tuffaceous sandstone 
are also found in the area north of San 
Jose Creek constituting the east end 
of the San Jose Hills. South of Spadra 
a few blocks of sandstone are included 
in the intrusive rocks, and there is @ 
vein of coarse calcite traceable for a 
| mile or more, which was burned for 
plaster by the early Spanish settlers. 
| (ee p, 293.) 
