diminishment

What happened

Diminishment means Congress shrinking a reservation's boundaries while leaving a reservation in place. Many cases arise from surplus-land acts that opened unallotted reservation land to non-Indian settlers. The question is whether the act also changed the boundary.

In Solem v. Bartlett (1984), the Supreme Court said: "Only Congress can divest an Indian reservation of its land and diminish its boundaries. But Congress must clearly evince an intent to change boundaries before diminishment will be found." The Court held that the 1908 Act at issue there opened the Cheyenne River Sioux land to sale but did not diminish the reservation.

Nebraska v. Parker (2016) restated the framework: the statutory text comes first, then "all the circumstances surrounding the opening of a reservation," and finally, to a lesser extent, later demographic history and treatment of the land. The 1882 Act at issue there did not diminish the Omaha Reservation.

The test does not always favor the tribe. In Hagen v. Utah (1994), the Court held that "the Uintah Reservation has been diminished by Congress," so the town of Myton was not in Indian country. In McGirt v. Oklahoma (2020), the Court wrote that once a federal reservation is established, only Congress can diminish or disestablish it, and that doing so requires a clear expression of congressional intent.

Summarized with AI assistance from 4 sources and checked against their words; not yet reviewed by historians or by the nations. Report an error