## Facts

- The Oneida Indian Nation’s aboriginal homeland encompassed millions of acres in central New York.
- A 1788 agreement with New York left the Oneidas a reservation of roughly 300,000 acres, later acknowledged and protected by the 1794 Treaty of Canandaigua.
- Despite federal restrictions on alienation of tribal lands, New York acquired substantial Oneida reservation land without federal approval, and Oneida landholdings in New York diminished to a small remnant by the early 20th century.
- In 1997–1998, the Oneida Indian Nation repurchased, on the open market, several parcels within the City of Sherrill that had historically been part of the Oneida reservation.
- The Nation declined to pay Sherrill’s property taxes, asserting the parcels were within an existing reservation and therefore immune from state and local taxation.
- Sherrill sought to impose and enforce property taxes, emphasizing that the area had been under state and local governance for generations and that the parcels had long been taxable.

## Issues

1. Whether the Oneida Indian Nation’s repurchase of historic reservation parcels allowed it to reassert sovereign authority over those parcels and render them immune from state and local property taxation.
2. Whether equitable doctrines and settled governance expectations can bar injunctive relief recognizing renewed tribal tax immunity after a long lapse of time.

## Decision

- The Supreme Court reversed the Second Circuit and vacated the injunction preventing Sherrill from taxing the parcels.
- The Court held that the Nation could not unilaterally revive sovereign authority and tax immunity over the repurchased parcels after approximately two centuries of non-Indian ownership and governance.
- The Court relied on equitable considerations (including laches-like delay, acquiescence, and impracticability) and the disruptive consequences of abruptly shifting regulatory and tax authority.
- The Court indicated that restoration of tax-immune status and tribal governmental authority over reacquired lands should proceed, if at all, through the federal land-into-trust process administered by the Department of the Interior.
- Justice Stevens dissented, arguing that only Congress can diminish a treaty-established reservation or remove tribal tax immunity, and that equity should not override the reservation’s legal status.

## Legal Principles

- A tribe’s open-market reacquisition of parcels within historic reservation boundaries does not, by itself, reestablish present-day tribal sovereignty or immunity from state and local property taxes.
- Equitable limits may bar prospective relief that would disrupt long-settled jurisdictional arrangements and justifiable expectations formed under generations of state and local governance.
- Prior recognition of a tribe’s ability to seek retrospective relief for unlawful dispossession does not require courts to recognize renewed territorial sovereignty over reacquired parcels.
- The principal mechanism for restoring a measure of tribal jurisdictional control and tax-advantaged status over reacquired lands is the federal land-into-trust process under 25 U.S.C. § 465 (now codified at § 5108), rather than unilateral assertions of sovereign authority.

## Conclusion

The Court held that, after a long period of non-Indian ownership and continuous state and local governance, the Oneida Indian Nation could not regain sovereignty and tax immunity over repurchased parcels simply by buying them on the open market; any such change generally must occur through the federal trust-acquisition framework, not judicially imposed tax immunity.


City of Sherrill v. Oneida Indian Nation of N.Y., 544 U.S. 197 (2005)