The Western United States: A Geographical Reader. Harold W. Fairbanks
and bottom of the cañon is equal to the change which the traveller experiences in a trip from the pine forests of the northern United States to the cactus-covered plains of Arizona.
As we look down from the top of the trail it does not seem possible to pass the great cliffs below, and yet there must be a way, since others have gone before us. All that we have to do is simply to follow the beaten path. Nature has conveniently left narrow shelves, crevices, and less precipitous slopes here and there, which need only the application of the pick and shovel to be made passable even for pack animals. Where the trail winds into shady recesses, we find stunted fir and pine trees clinging to the crevices and stretching their roots down into the waste rock collected upon projecting ledges.
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.
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.
We are now in the bottom of the main cañon, but deeper still is the last and inner gorge, through which the Colorado is flowing. For thousands of centuries the river has been sawing its way down into the earth. The precipitous cliffs which we have passed are formed of hard sandstone or limestone. The more gentle slopes consist of softer shales. Now the river has cut through them all and has reached the very heart of the earth, the solid granite.
This inner gorge has almost vertical walls twelve hundred to fifteen hundred feet high. We can sit upon the brink under a ledge of rock which protects us from the hot sun, and watch the river as we eat our luncheon. Far below, almost directly under us, it rushes along. The roar of the current rises but faintly to our ears. The water is very muddy and not at all like the clear mountain streams, far away upon the continental divide, which unite to form the river. It seems as if the water, ashamed of its soiled appearance, wanted to hide from the sight of men. If so, it has succeeded well, for it can be seen only at rare intervals from the top of the cañon walls, and even at the bottom of the main cañon the river itself is not visible unless one stands upon the very brink of the granite gorge.
The work of the river is not yet done. It will go on until the great cliffs have crumbled and have been replaced by gentle slopes. It will not stop until, at some far distant time, a broad valley has been worn out of the rocky strata.
The cañon appears much wider when viewed from the bottom than from the top, and the great cliffs far back along the trail seem less precipitous, but only because they are so far away. A weary climb of several miles awaits us. We must rest and take breath frequently or we shall not reach the top.
As night approaches and the shadows begin to fall, every turret and pinnacle stands out in bold relief. The bands of yellow and red shade into purple, and everything, save the long winding trail, begins to have a weird and mystical look.
HOW THE COLUMBIA PLATEAU WAS MADE
Years ago people disputed as to the way in which the earth was made. Those who lived where all the rocks had, like lava, the appearance of having once been melted, believed that fire had done all the work. Those who lived where the rocks appeared to be formed of hardened mud, sand, and lime, substances such as we find accumulating under water, said that water alone had been the means. But in later years the earth's surface has been more widely explored, and now it is known that both opinions were partly right. Water and fire have both been concerned in the making of the earth.
In the great valleys fire-formed rocks are rare, but they are more or less abundant in all mountainous regions, for where mountains are, there the crust of the earth is weakest. There are many reasons for believing that the interior of the earth is very hot. We know that the surface is settling in some places and rising in others, and that where the strain of the upheaval is too great the rocks are broken. These convulsions sometimes cause earthquakes and sometimes volcanic eruptions, when enormous quantities of molten rock are poured out over the surface. In all the long history of our earth probably no greater flood of lava than that which made the Columbia plateau was ever spread over the surface of any region. Travel where you will over the plains of southern Idaho, central Washington, or Oregon, and examine the rocks which here and there rise above the soil or are exposed in the cañons, and you will find that they all appear to have been formed by fire.
Just beginning to cut a cañon in the volcanic plateau
These rocks are dark in color and very hard. They are not arranged in regular layers like sandstone and shale; many of them show numerous little cavities which once contained steam. These cavities give to the rock a slag-like appearance. In this kind of rock, which we shall call lava, there are, of course, no remains of shells or bones of animals such as are often found in rocks formed from sand or clay.
Do not picture to yourself the Columbia plateau as one continuous stretch of level land, for it is broken by many mountain ranges. Some of these are old mountains which were too tall to be buried by the lava, but most of them have been formed out of the plateau itself. The eruptions which made the plateau extended through a very long time, perhaps hundreds of thousands of years, and the older lava is deeply decayed and covered with soil. Some of the later flows show extremely rough and rugged surfaces and are probably only a few hundred years old.
Long ago, before the eruptions began, the geography of the Northwest was very different from what it is now. Instead of a vast plateau there were mountains and valleys. Lowlands occupied most of the region where the Cascade Range now rises with its lofty volcanic peaks. Portions of the basin of the present Columbia River were occupied by lakes which extended southwest into California.
Movements