The Great Basin to-day is known to travellers principally by the many lesser deserts which compose it, deserts separated from each other by lesser mountain ranges and low divides. Its southern and southeastern boundaries are the plateaus and mountains which form the northern watershed of the muddy Colorado River and its confluents. South of the Colorado, the plateaus of New Mexico, Arizona, and southern California gradually subside to the Rio Grande. During this period and the Quaternary which followed it, volcanoes appeared in many places; their dead cones diversify our modern landscape. It was during the Quaternary Period, in whose latter end lives man, that erosion dug the mighty canyons of our great southwest. The Colorado was sweeping out the Grand Canyon at the same time that, far in the north, the glaciers of the Great Ice Age were carving from Algonkian shales and limestones the gorgeous cirques and valleys of Glacier National Park. XVI A PAGEANT OF CREATION GRAND CANYON NATIONAL PARK, ARIZONA. AREA, 958 SQUARE MILES There is only one Grand Canyon. It lies in northern Arizona, and the Colorado River, one of the greatest of American rivers, flows through its inner gorge. It must not be confused with the Grand Canyon of the Yellowstone, or with any of the _grande canyons_ which the Spaniards so named because they were big canyons. The Grand Canyon is 217 miles long, 8 to 12 miles wide at the rim, and more than a mile deep. It is the Colossus of canyons, by far the hugest example of stream erosion in the world. It is gorgeously colored. It is by common consent the most stupendous spectacle in the world. It may be conceived as a mountain range reversed. Could its moulded image, similarly colored, stand upon the desert floor, it would be a spectacle second only to the vast mould itself. More than a hundred thousand persons visit the Grand Canyon each year. In other lands it is our most celebrated scenic possession. It was made a national park in 1919. I The Grand Canyon is not of America but of the world. Like the Desert of Sahara and the monster group of the Himalayas, it is so entirely the greatest example of its kind that it refuses limits. This is true of it also as a spectacle; far truer, in fact, for, if it is possible to compare things so dissimilar, in this respect certainly it will lead all others. None see it without being deeply moved--all to silence, some even to tears. It is charged to the rim with emotion; but the emotion of the first view varies. Some stand astounded at its vastness. Others are stupefied and search their souls in vain for definition. Some tremble. Some are uplifted with a sense of appalling beauty. For a time the souls of all are naked in the presence.