The route runs by way of Cachi. The route between San Pedro and Cachi is supported by international arrangement between Argentina and Chile, each country supplying half the necessary cost, but the carriers are Argentinians wholly. From Cachi to Salta on the cast and from San Pedro to Calama on the west the mails are carried according to separate clomes- tic arrangements made by the respective governments. The mails from the east arrive at San Pedro on the 5th, 15th, and 25th of the month and leave on Thursday and Monday after- noons for Calama, so that two mails a week are maintained between San Pedro and the railway.
Passes, Trails, and Camps
Three principal trails cross the Puna de Atacama. The southernmost one leaves the railroad at Tinogasta (Fig. 1), goes northward to Fiambalé, thence west and north to the head of the Chaschuil valley, swings westward at the volcano San Francisco, finds the headwaters of the Copiapé River, and descends to Copiapé. ‘The trail has been in active use for more than a hundred years and was connected, through trib- utary trails, with Catamarca and other towns of north- western Argentina long before the railway reached these points. In fact, it long gave the settlements of northwestern Argentina their most direct access to the sea.
A second trail, of much less importance, extends from Ro- sario de Lerma southwest to Antofagasta de la Sierra, thence west across the Salar de Antofalla to Lorohuasi, and thence northward to Aguas Calientes (Fig. 1), and to the pass of Agua de la Falda in the Western Cordillera. Thereafter it crosses the Cordillera Domeyko and descends to the nitrate desert, with branches to the country back of the ports of Tal- tal and Chanaral. A third trail runs from Poma to Antofa- gasta de la Sierra. It was formerly a goods trail but is now used almost exclusively for the driving of cattle from the ranches of Salta in Argentina to the nitrate desert of Chile. There are other trails that branch off from these three main routes to touch at settlements of minor importance and to furnish alternative routes to secondary settlements on the two
