60 THE OASES OF THE NORTH-WEST 



that enabled them to dominate part of Argentina. 

 Colonization is even older here than in the Chaco 

 Salteno. It occupied two distinct periods, separated 

 by a long interval. At first it advanced from north 

 to south, passing round the foot of the Sierra. It is 

 marked by a line of springs, poor but permanent, 

 the waters of which are absorbed as soon as they flow 

 down to the porous alluvial beds of the plain. They 

 appear much in the names of the district aguitas, 

 aguaditas, and so on, abound. The road from La 

 Rioja to San Luis passed these springs, and some 

 population grew up about them. Thus the two sides 

 of the range the costa baja in the east and the costa alia 

 in the west became inhabited. The estate of Facundo 

 is one of these aguaditas of the costa alta. 



The two costas form the historic territory of the 

 Llanos. It was from there that colonization swarmed 

 over the plain long afterwards. This expansive move- 

 ment began about 1850 ; that is to say, at a time 

 when the breeders enjoyed comparative peace and 

 security, and especially when the invernadas of San 

 Juan and Mendoza were developed, together with the 

 export of cattle to the agricultural provinces of Chile. 

 The price of stock rose, and the unoccupied land became 

 of value. The occupation and exploitation of the 

 plain was the work of the last two generations. They 

 pushed on to the very edge of the salt lakes, leaving 

 no vacant space. The travesias which surrounded the 

 narrow inhabited zone of the costas were filled with 

 life. The Sierra and its two costas are no longer an 

 oasis in the desert, as they were in the time of Sarmiento ; 

 though they still differ from the remainder of the 

 pastoral zone in the density of their population and 

 the variety of their resources. 



The early date of the colonization may be traced in 

 a special system of tenure, though this is also found 

 in parts of the provinces of Catamarca and Santiago 

 del Estero. On the plain the right of ownership was 



