If it had not acted in good faith, the action was a taking under the Fifth Amendment.

Justice Blackmun’s majority opinion examined the historical record in detail.

It found, emphatically, that the government had not acted in good faith.

The evidence was substantial.

The “sell or starve” ration rider — Congress’s explicit threat to cut off subsistence rations unless the Sioux signed away the Hills — was coercion, not negotiation.

The failure to obtain three-fourths approval of adult male Sioux, as the Fort Laramie Treaty required, was not merely a procedural defect; it reflected the government’s decision to treat the treaty’s protections as obstacles to be circumvented rather than terms to be honored.