Navajo Fortress, the isolated high redstone butte located across the canyon, was once an important Navajo refuge from raiders: Spanish, American and perhaps other Indian groups.
Archeologists believe that the Navajo initially moved into the American Southwest sometime between AD 1300 and 1500, after moving south from the Canadian region. At this time they were following a nomadic hunting and gathering lifeway. Contact with the Pueblo Indian groups along the Rio Grande and with the Spainards in the 16th and 17th centuries resulted in agriculture, weaving and sheep herding being introduced into the Navajo culture. The earliest identifiable Navajo remains within the canyons date from the end of the 18th century; however, Spanish documents suggest that the Navajo were in the area before that time.
As pastoralism became increasingly important within their economy, the Navajo undertook livestock raids on the growing number of Spanish and later Anglo-American settlements encroaching upon their lands. the canyons appeared to be a Navajo stronghold to various military expeditions attempting to break the back of the Navajo resistance and raiding. The Spainards were never very successful and after the United States acquired the Southwest from Mexico in 1846, the responsibility for making the west safe for Anglo settlement fell to American military forces.
Various expeditions entered the canyons in the mid-1800s but usually saw few Indians or met little resistance, though planted fields and grazing sheep gave evidence of Indian occupation. Navajo raiding continued and a major attack by the Indians against Fort Defiance in 1860 convinced the military that their tactics had to change. Colonel Kit Carson employed a plan that would require little actual combat if it worked, yet would force the Navajo into surrendering. Carson's men destroyed corn fields and hogans in late summer and initiated sporadic small offensives during the fall of 1863. In the winter of 1864, he struck directly at Canyon de Chelly, and a sizable portion of the Navajo population, lacking sufficient supplies and without adequate shelter surrendered. Those who did so were moved to Fort Sumner, New Mexico, (Bosque Redondo) some 400 miles (640 km) away. The psychological impact of the move, called the Long Walk, was profound, and endures in the memory of many Navajo people today. Although the land at Fort Sumner was unsuitable for agriculture, the government attempted to make the canyon people, and some 8000 other pastoral Navajos brought together there, into agriculturists. Disease, drought, and severe storms made living conditions impossible, and finally, in 1868, the Navajos were released and allowed to return to their homelands within a new reservation that included Canyon de Chelly.
Navajo Fortress was used as a refuge throughout the period of Spanish and American military actions against the Canyon people. On the east side, not visible from the overlook, is a trail leading to the top of the fortress from the canyon floor. At a number of places, log poles which still stand, were used to connect the lower levels with otherwise inaccessible sections directly above. As the Navajos climbed, the pole were pulled up behind them. Also, located at strategic spots, are small rock walls behind which retreating Navajos hid while hurling rocks on intruders attempting to follow. Similar structures are found on the top of the fortress. Under the shelter of night, Navajos would sometimes sneak down and escape from the area or gather food and water for their people waiting above. Since the Carson campaign, the fortress has not been required as a defensive stringhold by the Navajo people.