Background & Facts
The 1868 Treaty of Fort Laramie set aside the Black Hills of South Dakota for the "absolute and undisturbed use and occupation" of the Sioux Nation. The treaty required the consent of three-fourths of the adult male Sioux population to be amended.
After gold was discovered in the Black Hills in 1874, the United States wanted the land. When the Sioux refused to sell, Congress passed the 1877 Act unilaterally seizing the Black Hills — without the three-fourths consent the 1868 Treaty required, and without paying the Sioux for the gold and timber the land contained.
A century later, the Indian Claims Commission and then the Court of Claims found that the 1877 taking violated the Fifth Amendment. The case reached the Supreme Court on the question of whether the federal government had liability and what compensation was owed.
The Court's Holding
Justice Blackmun, writing for an 8-1 majority, held that the 1877 Act effected a Fifth Amendment taking of the Black Hills. The federal government had violated its trust duty to the Sioux Nation by acting in its own commercial interest rather than protecting the tribe. The Court affirmed an award of $17.1 million (the 1877 value of the land) plus over $100 million in interest — a total of approximately $122 million at the time of the decision.
Famously, the Sioux Nation has refused to accept the money. The Black Hills are not for sale. The trust account containing the award (now well over $1 billion with accumulated interest) sits untouched.
Key Holding:
When the federal government takes treaty-protected tribal land without complying with treaty terms or providing fair compensation, it commits a Fifth Amendment taking and breaches its trust duty. Plenary power does not authorize the federal government to act against tribal interests for its own profit; the trust relationship is a limit on plenary power, not just its source.
Key Language
"A more ripe and rank case of dishonorable dealings will never, in all probability, be found in our history."
"[A]s the Court of Claims recognized, '[t]he duplicity of the United States toward the Sioux Indians in connection with the agreement of 1877 is a sad chapter in the history of our country.'"
"The 'good faith effort' and 'transmutation' of property concepts referred to in Lone Wolf are based upon the impossibility of judicial inquiry into the merits of an exchange between the Government and the Indians. Yet, as we discuss below, in the present case there is more than ample evidence that, when Congress chose, instead of negotiating, to take the lands, it knew it was taking property that the Sioux had not knowingly conveyed."
"Whenever Congress has chosen to act with respect to Indian property, it must have understood that the obligations of the United States as trustee are no less binding than those imposed by the Constitution."
Why Sioux Nation Matters for ATN
Sioux Nation is the case where the Supreme Court told the truth about how the United States acquired Indian land — and held the federal government legally accountable for it. For ATN, whose Mendocino Reservation arose from the same era of broken promises and unratified treaties, Sioux Nation does several important things at once.
Doctrinal contributions ATN can use:
- 1. Trust duty has teeth. Before Sioux Nation, the trust relationship was sometimes treated as aspirational — a moral framing without enforceable consequences. Sioux Nation made the trust duty cash-money real: the United States breached its trust and owed compensation. This is the foundation for any modern claim ATN might make about federal trust mismanagement of Mendocino lands or resources.
- 2. Plenary power is bounded by constitutional duties. Lone Wolf v. Hitchcock (1903) had treated plenary power as essentially unreviewable. Sioux Nation cabined that — when Congress acts in its own commercial interest rather than for the tribes' benefit, the action is reviewable as a Fifth Amendment taking. Plenary power authorizes federal action for tribes; it does not authorize federal action against tribes for the federal government's profit.
- 3. Treaties matter even when ignored. The 1868 Treaty's three-fourths consent requirement was technically dishonored by the 1877 Act, but a century later it provided the doctrinal anchor for an enormous award. Treaty obligations don't expire, and they don't dissolve when violated — they accrue claims that can be pursued generations later.
- 4. The "moral arc" framing. Sioux Nation's language ("dishonorable dealings... duplicity... a sad chapter") is unusually pointed for a Supreme Court opinion. ATN can cite Sioux Nation as judicial recognition that the historical pattern of federal dispossession is something the courts themselves view with shame — a backdrop that informs how every subsequent federal action toward tribes should be read.
- 5. The power of refusing to sell. The Sioux Nation has now refused to accept the Sioux Nation award for 45+ years. The trust account containing the money has accumulated to well over $1 billion. The Sioux position — the Black Hills are not for sale, no amount of money will substitute for the land — is a model of sovereign assertion that ATN can study and emulate. Money is not a substitute for land. Acceptance of compensation extinguishes the claim. Refusal preserves it.
Parallel to the Mendocino claim: The Mendocino Indian Reservation traces to the 1851 unratified California treaties — agreements the federal government negotiated but the Senate refused to ratify, with the result that the underlying Indian land claims were "extinguished" without compensation by later legislation. The factual posture is different from the Black Hills (where there WAS a ratified treaty), but the moral and doctrinal posture is closely related: federal action that dispossessed tribal communities without their consent and without compensation creates accruing claims that can be pursued generations later. Sioux Nation establishes the framework for thinking about what those claims look like and what remedies are available.
For PL280 specifically: Sioux Nation is not a PL280 case, but it provides the deeper doctrinal grounding for retrocession arguments. PL280 was an exercise of federal authority that imposed state jurisdiction on tribes without their consent. Under Sioux Nation's logic, federal action taken against tribal interests rather than for them is not insulated by plenary power — it is subject to review for breach of trust. ATN's argument that PL280 itself violated the federal trust duty owed to California tribes draws strength from the Sioux Nation framework.
Related Cases
- Lone Wolf v. Hitchcock (1903) — The case Sioux Nation cabined; plenary power as essentially unreviewable
- United States v. Kagama (1886) — Origin of plenary power doctrine, grounded in the duty of protection
- Cherokee Nation v. Georgia (1831) — Source of the federal trust doctrine that Sioux Nation enforced
- United States v. Winans (1905) — Reserved-rights doctrine: treaty rights are reservations, not grants
- Argument: The Federal Trust Doctrine