Down, down we go. The belt of the yellow pine and fir is left behind, and we come to the habitat of the piñon pine and juniper. These two will flourish where there is less moisture than is needed by the trees which grow nearer the top. Soon the trees have all disappeared and such plants as the greasewood, cactus, and agave take their place. Here, if it were not for the walls of rock rising on every hand, we might imagine ourselves upon one of the desert plains of Arizona.
[Illustration: FIG. 5.--CLIFFS ON THE TRAIL INTO THE GRAND CAÑON]
New views open at every turn in the trail, as it winds along the narrow shelves of rock with precipitous walls above and below. Now it zigzags back and forth down a gentle slope, but is soon stopped by another precipice. In one place, to escape a rocky point, the trail has been carried around the face of a cliff on a sort of shelf made of logs. It then passes through a crevice formed by the splitting away of a huge piece of the wall. In many places the grade is so steep that the trail is made practically a stairway, for the steps are necessary to keep animals from slipping.
Step by step we descend until the slope becomes more gentle and a sort of terrace is reached, where men are at work developing a copper mine. Everything needed for the mine is carried down packed upon the backs of sure-footed burros. Even the water has to be brought in kegs from a little spring still deeper in the cañon.
The trail leaves the mine and winds down past another cliff, until, when more than three thousand feet from the top of the plateau, we find water for the first time. The little springs issue from the sandstone, and their limited supply of water is soon drunk up by the thirsty sands.
As far as the water flows it forms a little oasis upon the barren slope. Along the course of the streams are little patches of green grass, flowers, and bushes. Birds flit about, and there are tracks of small animals in the mud. Evidently the water is as great an attraction to them as it is to us. If a well were dug in the plateau above, we can understand now how deep it would have to be in order to reach water. A well three-fourths of a mile deep would be a difficult one to pump.