the most populous of all North American Indian peoples in the United States, with some 300,000 individuals in the early 21st century, most of them living in New Mexico, Arizona, and Utah.

The Navajo speak an Apachean language which is classified in the Athabaskan language family. At some point in prehistory the Navajo and Apache migrated to the Southwest from Canada, where most other Athabaskan-speaking peoples still live; although the exact timing of the relocation is unknown, it is thought to have been between AD 1100 and 1500. These early Navajo were mobile hunters and gatherers; after moving to the Southwest, however, they adopted many of the practices of the sedentary, farming Pueblo Indians near whom they settled.

Navajo religion is widely practiced and notable for its intricacy. Some of its many traditions relate the emergence of the first people from various worlds beneath the surface of the earth; other stories explain the origins and purposes of numerous rites and ceremonies. Some of these are simple rituals carried out by individuals or families for luck in travel and trade or for the protection of crops and herds. More-complex rites involve a specialist who is paid according to the complexity and length of the ceremonial. Traditionally, most rites were primarily for curing physical and mental illness. In other ceremonies there were simply prayers or songs, and dry paintings might be made of pollen and flower petals. In some cases there were public dances and exhibitions at which hundreds or thousands of Navajo gathered. Many of these rites are still performed.

Although the Navajo never raided as extensively as the Apache, their raiding was serious enough to cause the U.S. government in 1863 to order Col. Kit Carson (Carson, Kit) to subdue them. The ensuing campaign resulted in the destruction of large amounts of crops and herds and the incarceration of about 8,000 Navajo, along with 400 Mescalero Apache, at Bosque Redondo, 180 miles (290 km) south of Santa Fe, N.M. This four-year (1864–68) captivity left a legacy of bitterness and distrust that has still not entirely disappeared.

In the early 21st century many Navajo continued to live a predominantly traditional lifestyle, speaking the Navajo language, practicing the religion, and organizing through traditional forms of social structure. Navajo men and women also continued the tradition of volunteering for the armed services at a high rate, perhaps as an expression of a cultural ethic that emphasizes both personal competence and community. In maintaining these disparate traditions, the Navajo have been cultural innovators. For example, the Navajo code talkers of World War II—Marines who used their native language to foil enemy monitoring of vital communications—played a definitive role in winning the war (and saved countless lives) by maintaining crucial radio contact on the battlefield.

Many Navajo continue to live in the area they settled centuries ago; in the early 21st century their reservation and government-allotted lands in New Mexico, Arizona, and Utah totaled more than 24,000 square miles (64,000 square km). The region is mainly arid, however, and generally will not support enough agriculture and livestock to provide a livelihood for all of its residents. Thousands earn their living away from the Navajo country, and appreciable numbers have settled on irrigated lands along the lower Colorado River and in such places as Los Angeles, Calif., and Kansas City, Mo.