F.  Exclusive Jurisdiction

25 U.S.C. § 1911(a)
The Indian tribe has exclusive jurisdiction over any child custody proceeding involving an Indian child who resides on or is domiciled within that tribe’s reservation, except where the jurisdiction is otherwise vested in the State by existing Federal law.

25 U.S.C. § 1911(a)
If an Indian child is a ward of a tribal court, however, the Indian tribe retains exclusive jurisdiction, notwithstanding the child’s residence or domicile.

25 U.S.C. § 1903(12)
A tribal court is a court with jurisdiction over child custody proceedings and may be either:
  • A Court of Indian Offenses;
  • The court established and operated under the code or custom of an Indian tribe;
  • Any other administrative body of the tribe which is vested with authority over child custody proceedings.
Mississippi Band of Choctaw Indians v. Holyfield, 490 U.S. 30 (1989)
A parent may not defeat the tribal court’s jurisdiction by leaving the reservation to give birth and relinquish custody off the reservation.

25 U.S.C. § 1922
If a child is a resident of or domiciled on a reservation, but is temporarily located off the reservation the ICWA allows emergency removal of that child to prevent imminent physical damage or harm. The emergency removal or placement must terminate immediately, however, when it is no longer necessary to prevent an imminent harm to the child and child custody proceedings shall be expeditiously initiated to transfer the child to the jurisdiction of the appropriate Indian tribe or to return the child to the parent or Indian custodian as appropriate.

25 U.S.C. § 1911(d)
Trial courts of this state and every Indian tribe must give full faith and credit to the public acts, records, and judicial proceedings of any Indian tribe applicable to Indian child custody proceedings to the same extent that such entities give full faith and credit to the public acts, records, and judicial proceedings of any other entity.

People in Interest of A.N.W., 976 P.2d 365 (Colo. App. 1999)
When a child resides off the reservation, however, jurisdiction is shared by the state and tribal court. 

People in Interest of J.L.P., 870 P.2d 1252 (Colo. App. 1994)
Notwithstanding the shared jurisdiction, the Tribal Court is still the preferred jurisdiction under the ICWA absent a showing of good cause to the contrary.