The United States Supreme Court has held that in child custody cases involving Indian children whose parents are domiciled on the reservation, the tribal court will have exclusive jurisdiction over the proceedings pursuant to section 1911(a) of the ICWA, despite the fact that the children were born off the reservation, voluntarily given up for adoption by both parents, and under state law the children's domicile was that of their adopted parents giving the state courts jurisdiction over the adoption proceedings.
Mississippi Band of Choctaw Indians v. Holyfield, __ U.S. ___, 109 S. Ct. 1597 (1989).
Indian Child Welfare Act - Adoptions - Domicile Defined,
Duq. L. Rev.
Available at: https://dsc.duq.edu/dlr/vol28/iss3/11