The census-enumerated American Indian population dispersed rapidly between 1930 and 1990. Changes in ethnic classification account for most of the change. In the 1980 count, 10 states with historically large Indian populations account for 53% of births of Indians between the ages of 10 and 80, compared with 72% of the first enumerations of the same cohorts. Migration further reduced the share of these states to 46% of Indian residents in these cohorts. Study of the dispersal of the Indian population should focus primarily on the new emergence of the expression of Indian identity, rather than on migration from former population centers.