Later the valles were incorporated in the many variations of the historic high road, one of the first and busiest of Spanish America, which goes from the Rio de la Plata to Lima: a route both for armies and merchants. The plan proposed by Matienzo (1566) to make a road from the silver mines to the estuary of the Paraná, through the Valle de Calchaqui, seems to have been intended merely to improve a line of communication that had already been in use. Buenos Aires for a long time received European goods by this road. About 1880 the Salta route recovered for a time its continental importance, during the Pacific War and the occupation by the Chileans of the maritime provinces of Bolivia.[20] At that time it was the only outlet for Bolivia.
VEGETATION OF THE INTERIOR VALLEYS (ANDES OF THE NORTH-WEST).
Descent of Tafi del Valle, going to Santa Maria. The ravine is excavated out of the mass of coarse deposits which forms a fringe between the mountain and the valley. On this permeable soil the vegetation is particularly thin. Cactus.
Photograph by the Author.
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FOREST ON THE OUTER SLOPE OF THE SUB-ANDEAN CHAINS.
Sierra de San Antonio (Salta province). Perennial foliage, creepers, ferns.