The Cliff Ruins of Canyon de Chelly, Arizona | Page 8

much in breadth. In the lower parts of the canyons the walls, sometimes of the character described, sometimes with the surfaces and angles smoothed by the flying sand, are generally vertical and often overhang, descending sheer to the canyon bottom without talus or intervening slopes of d��bris. The talus, where there is any, is slight and consists of massive sandstone of the same character as the walls, but much rounded by atmospheric erosion. The enlarged map (plate XLIII) shows something of this character.
Near its mouth the whole bottom of the canyon consists of an even stretch of white sand extending from cliff to cliff. A little higher up there are small areas of alluvium, or bottom land, in recesses and coves in the walls and generally only a foot or two above the stream bed. Still higher up these areas become more abundant and of greater extent, forming regular benches or terraces, generally well raised above the stream bed. At the Casa Blanca ruin, 7 miles up the canyon, the bench is 8 or 10 feet above the stream. Each little branch canyon and deep cove in the cliffs is fronted by a more or less extended area of this cultivable bottom land. Ten miles up the talus has become a prominent feature. It consists of broken rock, sand, and soil, generally overlying a slope of massive sandstone, such as has been described, and which occasionally crops out on the surface. With the development of the talus the area of bottom land dwindles, and the former encroaches more and more until a little above the junction of Monument canyon the bottom land is limited to narrow strips and small patches here and there.
These bottom lands are the cultivable areas of the canyon bottom, and their occurrence and distribution have dictated the location of the villages now in ruins. They are also the sites of all the Navaho settlements in the canyon. The Navaho hogans are generally placed directly on the bottoms; the ruins are always so located as to overlook them. Only a very small proportion of the available land is utilized by the Navaho, and not all of it was used by the old village builders. The Navaho sites, as a whole, are far superior to the village sites.
The horticultural conditions here, while essentially the same as those of the whole pueblo region, present some peculiar features. Except for a few modern examples there are no traces of irrigating works, and the Navaho work can not be regarded as a success. The village builders probably did not require irrigation for the successful cultivation of their crops, and under the ordinary Indian methods of planting and cultivation a failure to harvest a good crop was probably rare. After the Harvest season it is the practice of the Navaho to abandon the canyon for the winter, driving their flocks and carrying the season's produce to more open localities in the neighboring valleys. The canyon is not a desirable place of residence in the winter to a people who live in the saddle and have large flocks of sheep and goats, but there is no evidence that the old inhabitants followed the Navaho practice.
During most of the year there is no water in the lower 10 miles of the canyons, where most of the cultivable land is situated. The autumn rains in the mountains, which occur late in July or early in August, sometimes send down a little stream, which, however, generally lasts but a few days and fails to reach the mouth of the canyon. Late in October, or early in November, a small amount comes down and is fairly permanent through the winter and spring. The stream bed is even more tortuous than the canyon it occupies, often washing the cliffs on one side, then passing directly across the bottom and returning again to the same side, the stream bed being many times wider than the stream, which constantly shifts its channel. In December it becomes very cold and so much of the stream is in shade during a large part of the day that much of the water becomes frozen and, as it were, held in place. In the warm parts of the day, and in the sunshine, the ice is melted, the stream resumes its flow, and so gradually pushes its way farther and farther down the canyon. But some sections, less exposed to warmth than others, retain their ice during the day. These points are flooded by the water from above, which is again frozen during the night and again flooded the next day, and so on. In a short time great fields of smooth ice are formed, which render travel on horseback very difficult and even dangerous. This, and the scant grazing afforded by the bottom