In the case of Montana et al. v. United States et al., 1980, the U.S Supreme Court ruled that the Crow Tribe's right to regulate hunting and fishing on tribal lands was not absolute but subject to substantial federal control. The dispute arose when non-tribal members were prohibited from hunting or fishing on reservation land without a permit issued by the tribe, despite owning property within those boundaries. The court held that while tribes do retain some sovereign powers over their territory, these are subject to limitation by Congress and do not extend to activities involving non-members on non-Indian fee lands within reservations unless two exceptions apply: if nonmembers enter into consensual relationships with tribes or their members; or if conduct threatens political integrity, economic security, health or welfare of tribe. This ruling clarified limits of tribal sovereignty in relation to state authority.

In the dissenting opinion for Montana v. United States, Justice Blackmun argued that the majority's decision undermined tribal sovereignty and self-governance by limiting tribes' authority to regulate non-Indian fishing and hunting on reservation land owned in fee simple by non-Indians. He contended that this ruling contradicted previous court decisions which recognized inherent tribal power over all activities within a reservation, regardless of land ownership. Moreover, he asserted that Congress had not explicitly divested tribes of such regulatory powers; hence they should be presumed intact. The justice also criticized the majority's reliance on an 1868 treaty between Crow Tribe and U.S., arguing it was irrelevant as it did not address regulation of non-member activities on member-owned lands or mention any relinquishment of tribal jurisdiction over these lands.