Covering about 140,000 square miles, the Colorado Plateau physiographic province contains innumerable plateaus—John Wesley Powell originally used the plural, “Colorado Plateaus.” During the Paleozoic Era, tropical seas flooded the region, laying down sediments that solidifed into limestone, sandstone, siltstone, and shale in layers stacked on top of the Precambrian bedrock. Although seemingly a basin, the Plateau is in fact a high desert, uplifted by the same tectonic forces that raised the Rocky Mountains and Basin and Range, but with a difference—the land did not deform but instead rose as if an island drifting on a sea of magma, eventually rising higher than the Basin and Range. Yet it has succumbed to weathering. As the land rose, gathering streams cut ever deeper. Almost entirely drained by the Colorado River and its tributaries, the Plateau contains deep canyons and washes carved by erosion, leaving stranded plateaus, mesas, buttes, arches, and pinnacles—geologic wonders that never cease to amuse and amaze. This is America’s famous “Redrock Country,” a land of sand and sedimentary rock in places laid bare by erosion and so also termed “slickrock.”
Scattered pinyon pine/Utah juniper woodlands (Pinus edulis and Juniperus osteosperma) and open expanses dotted with sagebrush (Artemisia), saltbush (Atriplex), and blackbrush (Coleogyne ramosissima) reside on the tablelands. At the bottom of canyons, strips of green line the riparian corridors—cottonwood (Populus fremontii and angustifolia), willows (Salix), rabbitbrush (Chrysothamnus), greasewood (Sarcobatus vermiculatus), the non-native tamarisk (Tamarix aphylla).
Mule deer (Odocoileus hemionus) and pronghorn (Antilocapra americana) graze on sparse vegetation able to grow in the rain shadow of California’s Sierra Nevada Mountains, which capture most of the Pacific moisture moving east. Coyote (Canis latrans) are the primary predators, having made a comeback after the Department of Interior prohibited use of the poison 1080 (sodium fluoroacetate) on federal lands in 1972. Bobcat (Lynx rufus), grey fox (Urocyon cinereoargenteus), black-tailed jackrabbit (Lepus californicus), raven (Corvus corax), golden eagle (Aquila chrysaetos), and the rare black-footed ferret (Mustela nigripes) and cougar (Puma concolor) may be encountered in the backcountry. Black bear (Ursus americanus) and elk (Cervus Canadensis) occasionally pass through, and maybe someday gray wolf (Canis lupus) from the north and jaguar (Panthera onca) from the south. Native fish inhabit the rivers, including the Colorado River cutthroat trout (Oncorhynchus clarki pleuriticus). In addition to ravens and eagles, perhaps 200 bird species migrate through the region. Wild horse (Equus ferus) and burro (Equus africanus asinus) romp across the plains, brought by the Spanish and later American settlers. Desert bighorns (Ovis canadensis nelson) have been reintroduced; they were here in ancient times when the Anasazi carved or painted bighorn images across rock faces before even the Navajo were here.
Speaking a dialect of Athabaskan, a language spoken by First Nations in northwestern Canada, the Navajo encountered ancient ruins as they moved into the area from the north. They called these unknown people, Anasazi, meaning the “Ancient Ones.” Remnants of stone cities, the masonry as fine as Mayan or Inca, if not as large, still dot the Colorado Plateau, places like Chaco Canyon and Mesa Verde. Smaller cribs and rooms, even small abandoned communities, are scattered throughout the region, stuck in rock alcoves under an overhang like a child’s playhouse of mud and stone.
Sometimes called “Cliff Dwellers,” the Anasazi often built their settlements in the lee of a rock recess formed over eons of wind, rain, and the freezing/thawing of winter that chipped away at the sandstone. Speculation is that they chose such locations for protection.
Ancestors of present-day Pueblo people who still inhabit the Southwest, the Anasazi honed their arts of basketry, pottery, and masonry to culminate in the Great Pueblo Period that began around 1050 A.D. They became secure enough to build communal cities three and four stories high on the valley floors. Primarily farmers of corn, squash, and beans, sometimes cotton, the Anasazi were particularly vulnerable to drought. As a consequence, the towns were not occupied all at the same time, but rather the people moved as needed to be near water.
The Plateau towns and cities were abandoned by 1300. Although the Anasazi survived short periods of little rain, tree-ring evidence shows that a major drought occurred from 1276 to 1299, too long for the land to sustain the people, and so they slowly drifted away to the south, primarily to the Rio Grande drainage where water was available and they built new pueblos, joining others already there. Some are still inhabited today, like Taos Pueblo, a UNESCO World Heritage Site and National Historic Landmark, more than a thousand years old and the oldest continually occupied community in the U.S. And then there’s Pecos Pueblo, whose first buildings date from just before 1300, but abandoned in 1838 and now a National Historical Park and also a National Historic Landmark.
Perhaps if they had been left in peace, the Pueblo people would have once again reached the heights once attained by their ancestors, the Anasazi. As H. M. Wormington speculates in Prehistoric Indians of the Southwest, “It seems entirely possible that the Pueblo people might have achieved another remarkably high cultural stage had it not been for the arrival of the Spaniards in 1540.”