678 r. w. pack oil fields of the pacific coast 



Location of the Oil Fields 



When one thinks of the petroleum resources of the Pacific coast of 

 North America, it is the California fields that are the subject of atten- 

 tion; for, although oil is known to occur at other places in this general 

 region, practically all the present production is obtained in California, 

 and the most promising prospective territory. is likewise located in that 

 State. 



Seeps of light gravity oil are known both in Alaska and along the north- 

 west coast of Washington. AVells have been drilled at botli places and 

 a small quantity of oil produced in Alaska, but the results have not as yet 

 proven the existence of any considerable quantity of oil. It is probable 

 that, because of the complicated geology and the thick glacial and forest 

 cover, the prospecting for oil in both places will be slow and expensive, 

 and therefore that the development of these localities will await the ex- 

 haustion of the present better defined fields. As the information regard- 

 ing these areas is so meager and in general so unreliable, this discussion 

 will be confined to the California fields. 



California for several years led all the States in the quantity of oil 

 produced annually, and, although during the past two years it has been 

 surpassed by Oklahoma, it still contributes more than 30 per cent of the 

 total amount of oil produced annually in the United States. Were it not 

 for the retardation in development caused by controversies as to title of 

 lands within the productive fields, it is pfobable that the State would even 

 now lead all others in the quantity of oil produced annually. Moreover, 

 owing to the thickness of the productive sands, the annual decrease in 

 production is relatively small as compared to the Oklahoma fields, and 

 California will almost surely be in the first rank again before long. 



All the producing fields in California lie in the coast ranges which 

 border the Pacific Ocean and in the southern half of the State — that is, 

 south of the Bay of San Francisco. Various seeps of oil of excellent 

 quality, apparently superior to most of that obtained in the productive 

 fields to the south, occur in the northern Coast Ranges — that is, northward 

 from the bay as far as the Oregon line. This oil issues from Cretaceous 

 shales and sandstones similar, both in age and in general lithologic char- 

 acter, to the beds yielding oil in the Rocky Mountain fields; but, unlike 

 that region, the structure in the northern Coast Ranges does not appear 

 to favor the accumulation of oil, for the beds are in the main steeply tilted 

 and truncated along the flanks of the main mountain uplift. It thus 

 appears that not only is the present supply of oil on the Pacific coast com- 



