houses, after attaining a sufficient size, became overcrowded with inhabitants, it is probable that a strong colony, like the swarm from the parent hive, moved out, and commenced a new house, above or below, in the same valley. This would be repeated, as the people prospered, until several pueblos grew up within an extent of twelve or fifteen miles, as in the valley of the Chaco. When the capabilities of the valley were becoming overtaxed for their joint subsistence, the colonists would seek more distant homes. At the period of the highest prosperity of these pueblos, the valley of the Chaco must have possessed remarkable advantages for subsistence The plain between the walls of the canon was between half a mile and a mile in width near the several pueblos, but the amount of water now passing through it is small. In July, according to Lieutenant Simpson, the running stream was eight feet wide and a foot and a half deep at one of the pueblos; while Mr. Jackson found no running water and the valley entirely dry in the month of May, with the exception of pools of water in places and a reservoir of pure water in the rocks at the top of the bluff. The condition of the region is shown by these two statements. During the rainy season in the summer, which is also the season of the growing crops, there is an abundance of water; while in the dry season it is confined to springs, pools, and reservoirs. From the number of pueblos in the valley, indicating a population of several thousand, the gardens within it must have yielded a large amount of subsistence; the climate being favorable to its growth and ripening.
