Background & Facts
The Bay Mills Indian Community, a federally recognized tribe in Michigan, used settlement funds to purchase a parcel of land off-reservation and opened a casino on it. Michigan and a competing tribe sued, arguing that the casino violated the Indian Gaming Regulatory Act (IGRA) — which generally permits tribal gaming only on Indian lands — and seeking an injunction to shut it down.
Bay Mills argued tribal sovereign immunity. Michigan responded that the Court should either find an exception to sovereign immunity in IGRA or use the case as an occasion to overrule or substantially limit Kiowa Tribe v. Manufacturing Technologies (1998), the leading modern case on tribal sovereign immunity from suit for off-reservation commercial activities.
The Court declined both invitations.
The Court's Holding
Justice Kagan, writing for a 5-4 majority, held that tribal sovereign immunity bars suit against the tribe even for commercial activities and even when the activity occurs off-reservation. The Court reaffirmed Kiowa Tribe v. Manufacturing Technologies in full and refused to carve out an exception. Sovereign immunity can be overcome only by (1) clear congressional abrogation or (2) clear tribal waiver. IGRA's enforcement provisions did not unambiguously authorize the suit Michigan brought.
Key Holding:
Tribal sovereign immunity is alive, broad, and durable. It bars suit against the tribe even for commercial activities and even off-reservation conduct. It can be overcome only by (1) clear and unequivocal congressional abrogation or (2) clear and unequivocal tribal waiver. Courts will not infer either; both must be express.
Key Language
"Among the core aspects of sovereignty that tribes possess — subject, again, to congressional action — is the 'common-law immunity from suit traditionally enjoyed by sovereign powers.' That immunity, we have explained, is 'a necessary corollary to Indian sovereignty and self-governance.'"
"[U]nless and 'until Congress acts, the tribes retain' their historic sovereign authority. Among the core aspects of that sovereignty — and 'inherent in the nature of sovereignty itself' — is 'the common-law immunity from suit traditionally enjoyed by sovereign powers.'"
"[I]t is fundamentally Congress's job, not ours, to determine whether or how to limit tribal immunity. The special brand of sovereignty the tribes retain — both its nature and its extent — rests in the hands of Congress."
Justice Thomas, dissenting (joined by Scalia, Ginsburg, Alito): "I would overrule Kiowa." (The dissent's existence, and its 4-vote support, is a future warning sign — but it remains a dissent.)
Why Bay Mills Matters for ATN
Bay Mills is the most important modern affirmation of tribal sovereign immunity. The fact that the Court turned down a direct invitation from a state government to limit Kiowa — and did so specifically with respect to commercial off-reservation activity, where the doctrine is most vulnerable — is enormous. Tribal sovereign immunity remains the strong default, and the Court told states explicitly that it is Congress's job (not the courts') to limit it.
What Bay Mills gives ATN:
- 1. ATN is immune from California state suit. Absent an express congressional abrogation or an express ATN waiver, California cannot sue ATN — not for tax claims, not for regulatory violations, not for environmental claims, not for tort claims, not for contract disputes. The same applies to ATN's tribal entities, instrumentalities, and economic enterprises.
- 2. Immunity extends off-reservation and to commercial activity. ATN's federal contracting, GSA work, off-reservation business operations, and any commercial activity remain protected by sovereign immunity. This is one of the most economically valuable doctrines in modern Indian law.
- 3. Waivers must be express and unambiguous. ATN should be careful to include sovereign-immunity preservation language in every contract. An off-the-cuff arbitration clause or a broad "consent to jurisdiction" provision in a commercial contract risks being read as an implied waiver. The cleanest practice is to include explicit "ATN does not waive its sovereign immunity except as follows..." language.
- 4. The four dissents are a warning, not a defeat. Four Justices in 2014 wanted to limit Kiowa. The composition of the Court has changed since then. ATN should treat sovereign immunity as a current asset to be deployed, not a permanent guarantee — and should continue building the political case for codifying tribal immunity in federal statute.
- 5. Sovereign immunity protects the trust corpus. One of the practical effects of immunity is that creditors, judgment claimants, and adverse parties cannot reach tribal trust assets through state-court process. This protects ATN's land, resources, and economic enterprises from litigation-driven divestment.
For PL280 specifically: Sovereign immunity is the doctrine that prevents PL280 from doing the worst thing it might otherwise have done. Even where state courts have civil adjudicatory jurisdiction under PL280's 28 U.S.C. § 1360, they cannot use that jurisdiction to enter binding judgments against the tribe itself. ATN remains the immune defendant in California courts; only ATN-affiliated individuals (and only in their individual capacities) lose that protection. Bay Mills locks this in: PL280 transferred a forum, not the underlying immunity that prevents the forum from being used against the tribe as an entity.
Related Cases
- Santa Clara Pueblo v. Martinez (1978) — Foundational sovereign immunity case for internal tribal matters
- Haaland v. Brackeen (2023) — Modern reaffirmation of "muscular" congressional power and tribal sovereignty
- United States v. Wheeler (1978) — Inherent tribal sovereignty as the source of immunity
- Walker v. Rushing (8th Cir. 1990) — PL280 did not extinguish tribal authority — sovereign immunity is part of what survived