SANTA CLARA VALLEY: HOPPER-PIRU FIELDS. 
69 
leuni in this region, the center of curvature in this case being construed 
as a part of the axis of an anticline. Such an occurrence has been 
encountered at a number of points in the oil fields of the Coast Range. 
The anticline on which the San Cayetano wells are located has a 
northeasterly trend from a point a little southwest of the wells to the 
divide between Hopper and Reasoner canyons. The length of the 
fold is, therefore, about 2 miles. Except for these wells the anticline 
is unprospected, but there is no reason for the choice of one location 
over another. As the territory develops it will be interesting to note 
the success of drilling to the northeast of the present field. That the 
anticlines of this region may yield oil in more than one locality is evi¬ 
denced by the Modelo anticline, which carries the very productive 
territory of the Modelo wells and also that of the Sunset Oil Company. 
The yield of the San Cayetano wells is but 4 or 5 barrels of 14° grav¬ 
ity oil, but it is thought that this will increase as drilling is carried 
deeper. 
SUNSET WELLS. 
The Sunset wells, 11 in all, are located on the east side of Hopper 
Canyon, a short distance above the entrance of a lateral gorge that 
heads against Modelo Canyon. They penetrate the Modelo sand¬ 
stone, which occurs also in the wells of the Modelo Oil Company to 
the east. The dip of the beds is about 45° N.—that is, the wells 
have been drilled on the northern flank of an anticline the axis of 
which has a general N. 80° W. strike. Apparently the anticline is 
the same as the Modelo, although the connection between the two 
has not been traced. The area covered by the Sunset wells is some¬ 
what less than a half mile east and west by 500 to 600 feet north 
and south. 
The depth of the wells is generally less than 600 feet. The pro¬ 
duction is between 3 and 15 barrels per day, with a variable and in 
several wells excessive amount of water. It is thought that the 
production might be considerably increased by cleaning the wells. 
The oil is run into a common tank, and the gravity there obtained 
by the writer was 16.4° B. An initial yield as great as 75 barrels 
was obtained from certain of the wells several years ago. In Janu¬ 
ary, 1906, only five of the wells were being pumped. 
The Sunset wells afford another case of production in a region of 
highly crumpled strata and a rapid succession of flexures. 
FORTUNA WEL1£. 
The wells of the Buckhorn Oil and Transportation Company are, 
perhaps, best designated by their early name, Fortuna. The terri¬ 
tory is the farthest south of the productive areas in Hopper Canyon, 
lying about 2 miles north of the town of Buckhorn. 
Bull. 309—07-6 
