Does a tribe retain some elements of sovereignty over land that is not subject to exclusive jurisdiction of another tribe or that of the federal government?

A tribe retains some elements of sovereignty over all land within reservation boundaries, absent the exclusive jurisdiction of another tribe or that of the federal government (such as the establishment of a military base). With respect to non-Indian fee land within the reservation, the tribe retains sovereign power to the extent necessary to protect tribal self-government or control internal relations. Montana v. United States, 450 U.S. 544 at 564, 101 S.Ct. 1245, 1258, 67 L.Ed.2d 493. This includes the power to regulate commerce with the tribe or its members within reservation boundaries.