THE Navajo Indians of Arizona, Utah, and New Mexico, with a membership of over 90,000, are the largest Indian tribe in the United States, and their reservation, comprising some 16,000,000 acres, is the largest in area. It is a country of contrasts-forests and deserts; lakes and sand dunes; mountains and canyons. Collectively the Navajos are among the richest American Indians; individually they are among the poorest. With respect to culture contact and integration into the ways of the surrounding White society, there is wide variation from place to place. The ca'pital city, Window Rock, boasts handsome russet-colored sandstone administration buildings and Tribal Council Chambers where a newly elected Tribal Chairman recently walked down a red carpet to take his oath of office. There, too, is a modern Civic Center which presents an annual concert series which has included Fred Waring, Mahalia Jackson, Jose Iturbi, and other artists; local residents are offered FHAfinanced homes in a modern housing tract. Transitional communities such as Shiprock, Navajo, Fort Defiance, and Tuba City are variously supported by oil extraction, mining, lumbering, other wage-work interests, and irrigated farming. Also found on the reservation are geographically isolated communities where herding and marginal agriculture offer the only way of making a living and traditional ways are the mode; one such community is the subject of this study. In 1938, Malcolm Collier made a study of functional groups on Rainbow Plateau, a section of Navajo Mountain, in which she provided specific data on population, residence, clans, and kinship in this isolated, traditional area (Collier 1951). Through her generosity in sharing unpublished genealogies and information with the authors, we were able to make a diachronic study through specific comparisons between her data and the information we collected there during the summers of 1960, 1961, and 1962. The reader who is interested in synchronic studies of Navajo communities is referred to recent works by Adams (1963), Barnett (1952), Bosch (1961), Levy J. (1962), Moore (1962), Ross (1955), Richards (1963), and Sasaki (1960).