In a series of cases beginning with its 1981 decision in Montana v. United States, the U.S. Supreme Court has diminished the civil authority of Indian tribal governments over nonmembers within the tribes’ territories. Initially, the Court confined itself to hobbling tribes’ inherent sovereign authority over non-tribal members only on non-Indian (“fee”) lands within reservations. In 2001, however, the Court ruled for the first time that a tribe did not possess inherent jurisdiction over a lawsuit against state officers that arose on Indian (“trust”) lands. What that decision, Nevada v. Hicks, means for general tribal authority over nonmembers on Indian lands is not clear, however, and lower federal courts are struggling to interpret it. The primary issue is whether Hicks intended the Montana approach to extend to all nonmembers on trust lands or whether the decision in Hicks is confined to its particular set of facts. That uncertainty could lead to further inroads on the inherent sovereign authority of tribes.
The Court in Montana, however, recognized a second approach to tribal authority over nonmembers on trust land: the tribal treaty right of use and occupation. Although the Court held that those treaty rights are extinguished on fee lands, it agreed that the rights survive on trust lands. This Article argues that the treaty rights argument—that Indian tribes have rights to govern nonmembers on trust lands recognized by treaty and treaty-equivalent—must be resurrected. If inherent tribal authority over nonmembers on trust lands is under increasing judicial attack, tribes may assert their treaty right to govern as a path to ensure their sovereignty on Indian lands.