Here is the opinion: Big Spring Opinion.
An excerpt:
Julie Big Spring (Julie) and William F. Big Spring III (William) appeal the order of the Ninth Judicial District Court, Glacier County, denying their motion to dismiss for lack of subject matter jurisdiction. They challenge the District Court’s assumption of jurisdiction over the probate of the estate of their father, William F. Big Spring, Jr. (Big Spring), an enrolled member o f the Blackfeet Tribe whose estate property was located within the exterior boundaries of the Blackfeet Indian Reservation at the time o f his death. We reverse the District Court’s order and hold that the Blackfeet Tribal Court has exclusive jurisdiction over the probate of Big Spring’s estate (the Estate).
Here are the briefs.