On the steepest spurs of the Pampaconas Valley the traveler may go from snow to pasture in a half day and from pasture to forest in the same time. Another day he is in the hot zone of the larger valley floors, the home of the Machigangas. The steep descents bring out the superimposed zones with diagrammatic simplicity. The timber line is as sharply marked as the edge of a cultivated field. At a point just beyond the huts of Pampaconas one may stand on a grassy spur that leads directly up—a day’s journey—to the white summits of the Cordillera Vilcapampa. Yet so near him is the edge of the forest that he is tempted to try to throw a stone into it. In an hour a bitter wind from the mountains may drive him to shelter or a cold fog come rolling up from the moist region below. It is hard to believe that oppressive heat is felt in the valley just beneath him.
In the larger valleys the geographic contrasts are less sharp and the transition from mountains to plain, though less spectacular, is much more complex and scientifically interesting. The forest types interfinger along the shady and the sunny slopes. The climate is so varied that the forest takes on a diversified character that makes it far more useful to man. The forest Indians and the valley planters are in closer association. There are many islands and peninsulas of plateau population on the valley floor. Here the zones of climate and the belts of fertile soil have larger areas and the land therefore has greater economic value. Much as the valley people need easier and cheaper communication with the rest of Peru it is no exaggeration to say that the valley products, are needed far more by the coast and plateau peoples to make the republic self-supporting. Coca, wood, sugar, fruit, are in such demand that their laborious and costly transportation from the valleys to the plateau is now carried on with at least some profit to the valley people. Improved transportation would promote travel and friendship and supply a basis for greater political unity.
A change in these conditions is imminent. Years ago the Peruvian government decreed the construction of a railway from Cuzco to Santa Ana and preliminary surveys were made but without any immediate practical effect. By June, 1914, 12.4 miles (20 km.) had been opened to traffic. The total length of the proposed line is 112 miles (180 km.), the gauge is to be only 2.46 feet (75 cm.),[8] and the proposed cost several millions of dollars. The financial problem may be solved either by a diversion of local revenues, derived from taxes on coca and alcohol, or by borrowed foreign capital guaranteed by local revenues.
A shrubby vegetation is scattered along the valley from the village of Urubamba, 12,000 feet (3,658 m.) above sea level, to the Canyon of Torontoy. It is local and of little value. Trees appear at Ollantaytambo, 11,000 feet (3,353 m.), and here too are more extensive wheat and maize fields besides throngs of cacti and great patches of wild geraniums. On our valley journey we camped in pleasant fields flanked by steep hills whose summits each morning were tipped with snow. Enormous alluvial fans have partly filled up the valleys and furnished broad tracts of fertile soil. The patient farmers have cleared away the stones on the flatter portions and built retaining walls for the smooth fields required for irrigation. In places the lower valley slopes are terraced in the most regular manner ([Fig. 38]). Some of the fans are too steep and stony for cultivation, exposing bare tracts which wash down and cover the fields. Here and there are stone walls built especially to retain the rush of mud and stones that the rains bring down. Many of them were overthrown or completely buried. Unless the stream channels on the fans are carefully watched and effective works kept up, the labor of years may be destroyed in a single slide from the head of a steep fan.
Each group of fans has a population proportioned to its size and fertility. If there are broad expanses a town like Urubamba or a great hacienda like Huadquiña is sure to be found. One group of huge stony fans below Urubamba ([Fig. 180]) has only a thin population, for the soil is coarse and infertile and the rivers deeply intrenched. In some places the tiny fans perched high upon the flanks of the mountains where little tributaries burst out of steep ravines are cultivated by distant owners who also till parts of the larger fans on the main valley floors. Between the fans of the valley bottoms and the smooth slopes of the high plateaus are the unoccupied lands—the steep canyon walls. Only in the most highly favored places where a small bench or a patch of alluvium occurs may one find even an isolated dwelling. The stair-like trails, in some places cut in solid rock, zigzag up the rocky slopes. An ascent of a thousand feet requires about an hour’s travel with fresh beasts. The valley people are therefore walled in. If they travel it is surely not for pleasure. Even business trips are reduced to the smallest number. The prosperity and happiness of the valley people are as well known among the plateau people as is their remarkable bread. Their climate has a combination of winter rain and winter cold with light frosts that is as favorable for good wheat as the continuous winter cold and snow cover of our northern Middle West. The colder grainfields of the plateau are sowed to barley chiefly, though there is also produced some wheat. Urubamba wheat and bread are exported in relatively large quantities, and the market demands greater quantities than the valley can supply. Oregon and Washington flour are imported at Cuzco, two days’ muleback journey from the wheat fields of Urubamba.
Such are the conditions in the upper Urubamba Valley. The lower valley, beginning at Huadquiña, is 8,000 feet (2,440 m.) above sea level and extends down to the two-thousand-foot contour at Rosalina and to one thousand feet (305 m.) at Pongo de Mainique. The upper and lower sections are only a score of miles (30 km.) apart between Huadquiña and Torontoy, but there is a difference in elevation of three thousand feet (915 m.) at just the level where the maximum contrasts are produced. The cold timber line is at 10,500 feet (3,200 m.).[9] Winter frosts are common at the one place; they are absent altogether at the other. Torontoy produces corn; Huadquiña produces sugar cane.
These contrasts are still further emphasized by the sharp topographic break between the two unlike portions of the valley. A few miles below Torontoy the Urubamba plunges into a mile-deep granite canyon. The walls are so close together that it is impossible from the canyon floor to get into one photograph the highest and steepest walls. At one place there is over a mile of descent in a horizontal distance of 2,000 feet. Huge granite slabs fall off along joint planes inclined but 15° from the vertical. The effect is stupendous. The canyon floor is littered with coarse waste and the gradient of the river greatly steepened. There is no cultivation. The trees cling with difficulty to patches of rock waste or to the less-inclined slopes. There is a thin crevice vegetation that outlines the joint pattern where seepage supplies the venturesome roots with moisture. Man has no foothold here, save at the top of the country, as at Machu Picchu, a typical fortress location safeguarded by the virtually inaccessible canyon wall and connected with the main ridge slopes only by an easily guarded narrow spur. Toward the lower end of the canyon a little finer alluvium appears and settlement begins. Finally, after a tumble of three thousand feet over countless rapids the river emerges at Colpani, where an enormous mass of alluvium has been dumped. The well-intrenched river has already cut a large part of it away. A little farther on is Huadquiña in the Salcantay Valley, where a tributary of the Urubamba has built up a sheet of alluvial land, bright green with cane. From the distant peaks of Salcantay and its neighbors well-fed streams descend to fill the irrigation channels. Thus the snow and rock-waste of the distant mountains are turned into corn and sugar on the valley lowlands.