SOUTHWESTERN PLATEAUS AND MOUNTAINS 143. Character and ap pearance. — The South western Plateaus reach from northwestern Colorado southward through New Mexico and old Mexico to a point about a hundred miles south of the City of Mexico. Nearly all of the surface of this plateau is higher than any part of the Appalachian Plateau. The Mexican part of the plateau is higher than the American and therefore has a cool, healthful climate, although within the tropics. People need warm bed clothing at night.
This vast region is a dry and lonely land. Only in the highest parts is there enough rain to support forests. On most of the plateaus the bare earth shines out between scattering clumps of bunch grass and shrubs, for the water supply is very scanty. In every hillside are "barrancas," or gullies, that run with water only in the few short hours of rain. An American soldier, hunting for the Mexican bandit Villa, had, traveled many weary days over the Mexican part of this plateau. He said of it, " This is a country with more streams and less water, with more cows and less milk, and where you can look farther and see less than in any other country of the world." Water is so very scarce that the natives have learned to go for a long time without it. If you ask an Arizona Indian to have a drink of water, he will sometimes say, " No, thank you, I drank yesterday." At many places on the surface of the pla teau there are flat topped hills called mesas (Spanish for table). (Fig. 148.) 144. Bounds.—Bound the Southwestern Plateaus. On the northwest is a wild cliff called Hurricane Ledge (Fig. 239). On the southwest are the high mountains of western Mexico, where the Indian tribes rarely see a white man. In Texas and northwestern Mexico, the eastern edge of the plateau gives way to the lowlands by great "breaks," or steps, somewhat like the cliff in Fig. 129. South of the Rio Grande Valley, the eastern boundary of the plateau is a mountain, which rises above the plateau one or two thousand feet, and then plunges steeply down toward the Gulf of Mexico, as the western mountains do toward the Gulf of California and the Pacific.
145. Colorado Plateau and Canyon.—The most interesting part of all this plateau is that called the Colorado Plateau, drained by the Colorado River. This section is quite different from its neighbor, the Great Basin. The Great Basin, you remember (Sec. 137), has valleys filled with soil washed from the mountains. In the Colorado Plateau this whole country is high, the rivers have carved deep canyons in the hard, bare rocks (Fig. 239). A special railroad has been built to the place called Grand Canyon, Arizona, at the edge of a very famous valley. Many tourists go there to look into the deepest gorge in the world. There one may sit on the edge of a precipice (Fig. 146), and look straight down for thousands of feet, even a mile, and see at the very bottom of the valley the river shining like a little silver thread. This famous river has cut its gorge through rocks of many colors. In the morning, one side of the canyon lies in deep shadow. The variously-colored carvings on the other side shine in the sun. The view changes every hour. A thundercloud may rise up from the river, and while it is still far down in the canyon will throw back its moisture in a shower. The top of the cloud shines in the sun, while lightning flashes in the gloom beneath the cloud, and thunder echoes from cliff to cliff.
146. People.—On these Plateaus the na tive Indian makes up a larger share of the people than in any other part of our country. Several thousand Navajo Indians live on their reservation located near where the corners of Arizona, New Mexico, and Utah join. Many Indians support themselves by raising sheep, by selling hand-woven blankets, and by working on the railroads. The Hopis still make their living by raising sheep, and by tending little patches of irri gated corn down in the valleys. They make their homes in interesting villages on the tops of high, steep mesas. (Fig. 148.) Hundreds of years ago the forefathers of the _ _ _ _ tribe built the lages on mesas because those places were easy to defend against hostile Indian tribes.