172 
OIL DISTRICTS OF SOUTHERN CALIFORNIA. 
DEVELOPMENT. 
The central is the oldest field in the Los Angeles district, its first 
productive well having been sunk in 1892. As soon as oil was assured 
other wells were drilled in the immediate vicinity, and the field grew 
rapidly. The development of that part of the field lying east of 
First street was practically complete by the end of 1896, while most 
of the wells in the western part were sunk during the period from 
1897 to 1900. There are at present (February, 1906) 516 wells in 
the central field, of which 206, or about 40 per cent, are pumping, 
while 310, or about 60 per cent, are either abandoned or not pumping. 
In the region west of Bonnie Brae street the proportion of pumping 
wells is 60 per cent, but in the eastern part of the field it is only 31 
per cent. This is doubtless due to the greater age of the eastern 
wells. The wells vary in depth from 500 to 1,400 feet, averaging 
deeper in the western than in the eastern part. The eastern wells 
now produce from 2 to 8 barrels per day, and the western wells go 
considerably higher, some possibly to 12 or 15 barrels. The average 
for the field is said to be about 4 barrels. At their inception some of 
the wells in the western part of the field gave 60 barrels per day, 
but soon fell off to 20 barrels. The gravity of the oil in this field 
varies from 14° to 16° B. 
WESTERN FIELD. 
LOCATION. 
The western field includes all of the oil-producing territory lying 
to the west and northwest of Coronado street, north of Westlake 
Park, with the exception of the area described on pages 186-195 as 
the Salt Lake field. In its restricted sense the western field is a belt 
trending N. 70° W., about one-half mile wide at its southeast end 
and one-fourtli mile wide at its western terminus southeast of Cole- 
grove. Within this area of about 1| square miles are four rather 
distinct groups of wells, the area covered by them being, something 
less than one-lialf the total area of the oil-yielding belt. 
TOPOGRAPHY. 
The region of the western field, viewed topographically, is one of 
transition from the pronounced hilly country northwest of Elysian 
Park to the broad, gently southward-dipping Los Angeles-Santa 
Monica plain. Its characteristic features are low rolling hills, sepa¬ 
rated by more or less strongly pronounced ravines, which run in a 
southerly or southwesterly direction. 
