But, though what may be called the pure mountain-peaks do not entail the same perils and difficulties as the members of the Alpine Club discover in Italy, France, Switzerland and Germany, the volcanic cones and canon-walls of the West have an unstable verticality which, when it is not absolutely insurmountable, is more difficult than the top of the Matterhorn itself; and though the various expeditions under Wheeler, Powell, King and Hayden have not had Aiguilles Vertes to oppose them, they have been confronted by obstacles which could only be overcome by as much courage as certain of the clubmen have required in their most celebrated exploits. Indeed, nothing in the journals of the Alpine Club compares in the interest of the narrative or the peril of the undertaking with Major Powell's exploration of the canons of the Colorado, which, though its history has become familiar to many readers through the official report, gathers significance in contrast with all other Western expeditions, and stands out as an achievement of extraordinary daring. The Colorado is formed by the junction of the Grand and Green Rivers. The Grand has its source in the Rocky Mountains five or six miles west of Long's Peak, and the Green heads in the Wind River Mountains near Fremont's Peak. Uniting in the Colorado, they end as turbid floods in the Gulf of California, a goal which they reach through gorges set deep in the bosom of the earth and bordered by a region where the mutations of Nature are in visible process. In all the world there is no other river like this. The phenomenal in form predominates: the water has grooved a channel for itself over a mile below the surrounding country, which is a desert uninhabited and uninhabitable, terraced with long series of cliffs or _mesa_-fronts, verdureless, voiceless and unbeautiful. It is a land of soft, crumbling soil and parched rock, dyed with strange colors and broken into fantastic shapes. Nature is titanic and mad: the sane and alleviating beauty of fertility is displaced by an arid and inanimate desolateness, which glows with alien splendor in evanescent conditions of the atmosphere, but which in those moments when the sun casts a fatuous light upon it is more oppressive in its influence upon the observer than when the blaze of high noon exposes all of its unyielding harshness. To the feeling of desolation which comes over one in such a region as this a quickened sense and apprehension of the supernatural are added, and we seem to be invaders of a border-land between the solid earth and phantasy. Nature is distraught; and so much has man subordinated and possessed her elsewhere that here, where existence is defeated by the absolute impossibility of sustenance, a poignant feeling of her imperfection steals over us and weighs upon the mind.