This article demonstrates the importance of investigating language variation and change both within and across ethnic groups, especially those that have been relatively insular historically. The focus is on the variable patterning of /ay/ in the variety of English spoken by the Lumbee Indians in tri-ethnic Robeson County, North Carolina. (The Lumbee refer to themselves as “Indians” rather than “Native Americans”; I use their term when referring to their tribe.) The analysis reveals that the Lumbee have been surprisingly innovative and heterogeneous. Explanations are both linguistic and extralinguistic. Insular groups do not face linguistic pressure to level intra- and inter-community differences or to curb internal innovations. In addition, insular groups are often more concerned with intra- than inter-group relations and hence with intra-group social and linguistic distinctions. The study also shows a lessening of inter- and intra-group dialect differences with increased inter-group contact. However, the Lumbee still preserve a degree of dialectal distinctiveness, indicating that the need to preserve cultural uniqueness may outweigh linguistic pressure to level out differences.