4 
OIL DISTRICTS OF SOUTHERN CALIFORNIA. 
The centers of settlement in the Santa Clara Valley include Ven¬ 
tura, Santa Paula, Fillmore, Piru, Newhall, Camulos, and Saugus, 
their relative importance being in the order named. 
The oil fields north of the Santa Clara Valley are developed on the 
open slopes in front of Mount San Cayetano and in the tributary can¬ 
yons to a distance into the range of 5 to 10 miles. These fields 
include in succession from east to west, Piru, Modelo, Nigger, Hop¬ 
per, Tar, Little and Big Sespe canyons, and the San Cayetano, Silver 
Thread, and Ojai fields. They follow in their development the line of 
the higher mountains. From Santa Paula Canyon westward, how¬ 
ever, there is a line of wells in Adams, Salt Marsh, Wheeler, and Aliso 
canyons, along the south side of Sulphur Mountain, in strata younger 
than those carrying most of the wells in the fields just referred to. 
Prospecting is carried on west of Aliso Canyon, even as far as the 
valley of Ventura River, but no productive territory has yet been 
found in that area. 
The productive wells south of the Santa Clara Valley are confined 
to the northern slopes of the Santa Susana Mountains and Oak Ridge, 
with the exception of a single well in the canyon of Placerita Creek, a 
stream which drains a portion of the northwestern slope of the San 
Gabriel Range. The field in which this well lies is the easternmost 
of those developed. Next westward is the Elsmere field, a mile or two 
southeast of Newhall; to the southwest of Newhall, in canyons de¬ 
scending from the Santa Susana Mountains, are, successively, the 
Rice, Wiley, Towsley, Dewitt, and Pico fields, the last noted in the 
past, as well as at present, for the lightness of its oil and the magni¬ 
tude of its production. Along the northern face of Oak Ridge, 5 or 
6 miles west of the Pico field, are those lying in Tapo, Eureka, and 
Torrey canyons; Wiley, Garberson, Shields, Grimes, and other can¬ 
yons have also been prospected, but without much success, except 
in the case of Grimes Canyon, west of which no developments have 
thus far taken place. 
The railway connection for these oil fields is the Coast division of 
the Southern Pacific, which unites with the San Joaquin Valley 
division at Saugus and passes thence southward to Los Angeles, dis¬ 
tant 33 miles. 
GEOLOGIC FORMATIONS.a 
GENERAL STATEMENT. 
The formations of the Santa Clara Valley include certain Pleisto¬ 
cene beds of which the precise horizon is not determined; a great 
series of conglomerates, sandstones, and arenaceous clays which were 
designated by Hamlin some years since as the Fernando formation 
a See p. 143 for table of tentative correlations between the oil-bearing formations of southern Cali¬ 
fornia. 
