credit system, its modes of transport, its community life, the way in which the land is utilized, the coming and going of the nomadic mountain shepherds, relations with tributary oases scattered in still more remote and isolated valleys up and down the western flank of the cordillera—all these give it a distinc- tive quality, and yet at the same time it serves as an example of the mode of organization and of the functioning of a distant desert town tied equally to the great wastes of highland Ata- cama and the lofty mountains and to the distant settlements beyond them.
Just as Copiapé serves to illustrate the life of larger com- munities based on irrigation but dependent also upon mines and railway, so San Pedro illustrates the structure of the smaller communities distant from the railway and resting their economic life upon the old and primitive means on which they have depended ever since their foundation centuries ago.
The dependence of the shepherds upon the high pasture along the western flank of the Andes and also the local pastures on the eastern slopes and basins of the main chain that forms the international boundary makes it difficult to administer a customs service precisely upon the boundary line, for the site is both cold and inaccessible. The shepherds pay no attention to the boundary in fact, and both Argentinian and Chilean slopes of the Western Cordillera are tributary to San Pedro. The customhouse is not located in the settlements at the base of the mountains but is near Tambillo, where the trails from the mountains converge toward San Pedro. The duty upon Argentine sheep driven across the international boundary into Chile is 4 pesos Chilean per sheep and 40 or 50 pesos per 100 pounds of wool.
The Economic Life of the Oasis
On account of the dependence of San Pedro upon the cattle trade, the proposed railway across the mountains by way of the Guaitiquina gorge meets with disfavor here, for if it reached the coast by running south of the salar it would divert to another route the cattle trade, now the chief transport busi- ness of the town and the chief support of the alfalfa industry.