In a space so limited as that which is available here one can not do more than sketch, in the shortest sort of an outline, the features characteristic of the oil fields along the Pacific coast of North America. The writer will, therefore, present here only a brief discussion of the broader geologic features that appear to be common to the California fields. Although these fields are among the more recently developed ones, and although the geology—stratigraphy and structure alike—of the region in which the fields lie is woefully complicated, still the larger geologic features that govern the occurrence of petroleum in these fields are pretty well known, probably better known than they are for many other fields in the United States. No attempt will be made to outline or to discuss the areas of prospective value or to estimate the quantity of petroleum available in this region. . . .