Page:Isaiah Bowman - Desert Trails of Atacama (1924).pdf/360

 buried under snow or troubled with hail it is on their upper fringe only, for elsewhere the snowfall is so light that an hour of morning sunshine dissipates it. Virtually the whole of the pasture belt is open for stock the year round.

In southern Peru, along the 73rd meridian, | passed a per- manent habitation at 17,100 feet, or only a little below the snow line, believed to be the highest permanent habitation yet found anywhere in the world. Hundreds of alpacas and sheep grazed on the hill slopes and valley floors roundabout; and their tracks showed plainly that they were frequently driven up to the snow line in those valleys, where a trickle of water supports a band of pasture. Less than 100 feet below them were other huts and flocks. The situation illustrates the ex- tent to which the high pastures may be utilized. High valleys at 16,000 fect are frequent in which a thick carpet of grass supports large flocks of sheep, llamas, and alpacas; and the valley floor is the site of numerous huts and corrals.

By contrast, the highest permanent habitations above Poma in the region of Pefias Blancas were at 11,000 feet. No per- manent settlements aside from individual huts or shelters can be found at higher elevations, and no towns at all. The ham- lets or villages mentioned in Chapter XV are all below 12,000 feet. No town of real consequence and, with the exception of San Antonio de los Cobres, none at all with a population ex- ceeding 500 lies above 10,000 feet. No town of more than 1000 lics above the forest zone. To find towns of this size we must go into the forest belt or immediately below it. Such, for ex- ample, is the situation of Salta, Jujuy, Tucuman, Catamarca, as well as a host of lesser towns among or near them. All the settlements are closely associated with the eastern slopes rather than the Puna or the coastal desert. That is, instead of avoid- ing the rainy belt as in Peru and northeastern Bolivia the popula- tion seeks it on the border of the Puna.

There is no present prospect of the development of minerals in the Puna de Atacama on such a scale as to support a large