While the cultivated area was thus growing toward the south, it was being reduced in the north of the province of Buenos Aires and the south of Cordoba. The lands of the lower Rio Cuarto were not occupied. About 1860 (Martin de Moussy) the farthest establishments in this sector were S. Jose de la Esquina and Saladillo on the Tercero. The road to Chile by the Rio Cuarto, Achiras, and San Luis was threatened. The advance of colonization in this zone was at first in the west to Villa Mercedes on the Rio Quinto. The line of the Rio Cuarto by Carlota was reoccupied, and before 1875 the frontier had been pushed back to the Rio Quinto, where it joined the forts of southern Buenos Aires by way of Sarmiento, Gainza, and Lavalle. At last, in 1878, General Roca abandoned the classical methods of fighting the Indians, and took the offensive. He deprived the Indians of their refuges to the south of San Luis and the Central Pampa, and threw them back toward the desert. The Argentine troops followed in their steps as far as the Andes and the Rio Negro. There are to-day few traces in the immense territory that was won of the indigenous population. Its extreme mobility had masked its numerical inferiority.[6] [6] M. J. Olascoaga gives (_La conquete de la Pampa: Recueil de documents relatifs a la campagne du Rio Negro_, Buenos Aires, 1881) valuable documents concerning both the details of the fight with the Indians and the distribution of their _invernadas_ (common lands) in the region of the Pampas. Olascoaga translates it "winter quarters"; it was pasturage on which they kept their cattle and from which they set out on their expeditions. The history of the northern frontier is much the same. At the end of the eighteenth century the Spanish outposts ran along the course of the Salado. To the north of Santa Fe, at Sunchales, Soledad, and San Javier, they protected the direct route from Santa Fe to Santiago del Estero. These outposts were abandoned during the revolutionary period, and the Indians advanced as far as the suburbs of Santa Fe. The roads both to Santiago and, by the Quebracho Herrado, to Cordoba were cut.[7] Urquiza reorganized the Santa Fe frontier, first as far as San Javier, then below 29 deg. S. lat. between Arroyo del Rey on the Parana and Tostado on the Salado. The expedition of 1884 brought the Argentine army as far as the Bermejo, and broke the resistance of the Tobas. The forts which, more to the north, guarded the province of Salta, on the further side of the Sierras de la Lumbrera and Santa Barbara, had been dismantled at the beginning of the nineteenth century, as the tribes in this part of the Chaco were not hostile.[8] [7] See Thomas J. Hutchinson, _Buenos Aires and Argentine Gleanings_. [8] See Geronimo de la Serna, "Expedicion militar al Chaco," _Bol. I, Geog. Argentino_, xv. 1894, pp. 115-79.