Overview
The Supreme Court has developed three rules that govern the interpretation of Indian treaties, called the "Canons of Treaty Construction." These canons are among the most powerful tools in federal Indian law. They require courts to resolve ambiguities in favor of tribes, interpret treaties as the Indians understood them, and construe treaty language liberally to protect Indian rights.
These canons are not merely guidelines — they are binding rules of law that the Supreme Court has applied consistently for over a century. Any court interpreting a treaty with an Indian tribe is required to apply these canons.
Ambiguities Must Be Resolved in Favor of the Indians
Where a treaty provision is ambiguous, the ambiguity must be resolved in favor of the Indian tribe — not the government.
This canon reflects the fundamental principle that Indian treaties were negotiated between parties of vastly unequal bargaining power. The federal government drafted the treaties in English, a language most tribal signatories did not read or write. Courts therefore refuse to hold tribes to technical interpretations they could not have understood or intended.
Controlling Authorities
Carpenter v. Shaw, 280 U.S. 363, 367 (1930)
SCOTUSThe Court held that doubtful expressions in treaties are to be resolved in favor of the Indians, establishing the foundational principle that treaty ambiguities cannot be used against the tribes who signed them.
DeCoteau v. District County Court, 420 U.S. 425, 447 (1975)
SCOTUSReaffirmed that ambiguous treaty language must be construed in favor of the Indians, particularly when the question involves the diminishment or disestablishment of reservation boundaries.
Bryan v. Itasca County, Minnesota, 426 U.S. 373, 392 (1976)
SCOTUSApplied the canon directly to P.L. 280, holding that ambiguities in federal statutes affecting Indian rights must be resolved in favor of the tribes. This case is particularly significant for ATN's P.L. 280 arguments — the Court held that P.L. 280 did not grant states taxing authority over Indian property on reservations.
Treaties Must Be Interpreted as the Indians Understood Them
A treaty must be construed not according to the technical meaning of its words to learned lawyers, but in the sense in which they would naturally be understood by the Indians.
This canon requires courts to step outside the Anglo-American legal tradition and consider what the Indian signatories actually believed they were agreeing to. Treaties were typically negotiated through interpreters, often in council settings governed by Indian protocol. The words on the page — written in English by government agents — are not necessarily what the tribes consented to.
Controlling Authorities
Jones v. Meehan, 175 U.S. 1, 10 (1899)
SCOTUSThe foundational case establishing this canon. The Court declared that Indian treaties "must be construed, not according to the technical meaning of its words to learned lawyers, but in the sense in which they would naturally be understood by the Indians."
United States v. Shoshone Tribe, 304 U.S. 111, 116 (1938)
SCOTUSThe Court applied the Indian-understanding canon to hold that treaty language reserving land to the Shoshone must be read as the Shoshone understood it — as a guarantee of exclusive use and occupancy, not merely a paper concession.
Choctaw Nation v. Oklahoma, 397 U.S. 620, 631 (1970)
SCOTUSReaffirmed the Indian-understanding canon and applied it to determine that the Choctaw and Cherokee Nations retained rights to the bed of the Arkansas River — because the tribes understood their treaties to include riverbed rights, regardless of the technical legal meaning of the language used.
Treaties Must Be Construed Liberally in Favor of the Indians
Indian treaties are to be interpreted liberally in favor of the Indians, and any limitations on rights granted by treaty must be narrowly construed.
This canon is the broadest of the three. It goes beyond resolving ambiguities — it requires courts to affirmatively read treaties in the way most favorable to the tribe, even when the language is not strictly ambiguous. Rights reserved by the tribe are read broadly; limitations imposed on the tribe are read narrowly.
Controlling Authorities
Tulee v. Washington, 315 U.S. 681, 684-85 (1942)
SCOTUSThe Court held that a treaty right to fish "at all usual and accustomed grounds and stations" could not be defeated by state licensing fees. Treaty-reserved rights must be construed liberally — the state cannot use regulatory fees to effectively destroy a treaty right.
Washington v. Washington State Commercial Passenger Fishing Vessel Ass'n, 443 U.S. 658, 690 (1979)
SCOTUSOne of the most consequential Indian treaty cases. The Court held that Pacific Northwest tribes were entitled to up to 50% of the harvestable fish, reading the treaty language "in common with" as guaranteeing a fair share — not merely the right to stand on the riverbank alongside non-Indians. This liberal construction transformed Indian fishing rights across the region.
Oneida County, N.Y. v. Oneida Indian Nation, 470 U.S. 226, 247 (1985)
SCOTUSThe Court held that the Oneida Indian Nation had a federal common law right of action for an illegal conveyance of tribal lands in 1795. Liberal construction of Indian treaty rights meant that even centuries-old land claims could be pursued when the original transfer violated the Indian Nonintercourse Act.
The Federal Protection Duty — Treaty Promise as Source of Power
Many Native treaties guarantee that the federal government will "protect" the treaty tribes. The Supreme Court held that this promise gave the federal government not only the duty to protect them but also the power to do so.
United States v. Kagama, 118 U.S. 375, 382-83 (1886)
SCOTUSThe Court upheld the Major Crimes Act, holding that the federal government's duty of protection — arising from treaties and from the dependent relationship — carried with it the power to enact legislation governing Indian Country. This case arose from the Hoopa Valley Reservation in California, making it directly relevant to ATN and Mendocino County tribal jurisdiction.
NOTE: While Kagama established the "plenary power" doctrine, ATN's position is that this power is a power of protection, not domination. Federal power over Indian affairs exists to fulfill treaty promises — not to override tribal sovereignty. P.L. 280's imposition of state jurisdiction without consent violated this protective purpose.
The Evolving Sources of Federal Power Over Indian Affairs
It has been many years since the Court has cited the Treaty Clause, the discovery doctrine, or the doctrine of trust responsibility as a source of federal power over Indians. Today, only the Commerce Clause (Article I, § 8, cl. 3: "To regulate Commerce ... with the Indian Tribes") is cited as the constitutional basis for federal Indian legislation.
Each of the historical justifications for federal control over Indian affairs can be disputed:
| Doctrine | Claimed Basis | Disputable Because |
|---|---|---|
| Treaty Clause | Art. II, § 2 — President's treaty-making power | Treaty-making with tribes was abolished in 1871 (25 U.S.C. § 71); existing treaties remain binding but no new ones can be made |
| Discovery Doctrine | Johnson v. M'Intosh (1823) — European "discovery" gave title | Rooted in the Doctrine of Christian Discovery, widely condemned; does not create regulatory power over internal tribal affairs |
| Trust Responsibility | Cherokee Nation v. Georgia (1831) — "domestic dependent nations" | Trust is a duty to protect, not a license to control; trust obligations run in favor of tribes, not against them |
| Commerce Clause | Art. I, § 8, cl. 3 — regulate commerce "with the Indian Tribes" | Currently the only cited basis; "commerce with" implies a bilateral relationship, not unilateral control over internal tribal governance |
Why the Canons Matter for Agency Tribal Nations
The Canons of Treaty Construction are directly applicable to ATN's sovereignty arguments under the 1856 Mendocino Indian Reservation Treaty:
- Canon I (Ambiguity): Any ambiguity in P.L. 280's application to the Mendocino Indian Reservation must be resolved in ATN's favor — exactly as Bryan v. Itasca County held.
- Canon II (Indian Understanding): The 1856 Treaty must be interpreted as the Mendocino Indians understood it — as a guarantee of their homeland and self-governance, not as a submission to state jurisdiction.
- Canon III (Liberal Construction): Rights reserved by the Mendocino Indians under the 1856 Treaty — including the right to self-governance on their own land — must be construed broadly. P.L. 280's limitations on those rights must be construed narrowly.
- Protection Duty: The federal government's treaty promise to protect the Mendocino Indian Reservation creates an obligation to shield ATN from state encumbrance — not a power to impose it.