Until the 1980s, in cases involving historic treaties with American Indian tribes, the U.S. Supreme Court was guided by a pair of Indian law canons:

First, ambiguities in treaties were to be resolved in favor of the Indians. Second, treaties were to be interpreted as Indians themselves had understood them.

These canons were not controversial. Their corollary in civil law — that ambiguities in a contract should be construed against the drafter of that contract — finds ample support in legal jurisprudence. However, as Stanford Law Prof. Gregory Ablavsky has noted, “recent Supreme Court decisions have sometimes honored [these canons] in the breach.”

Led by late Chief Justice William Rehnquist, over the last three decades an activist Supreme Court began substituting its own policy judgments in place of the rights secured by Indian treaties and federal statutes. For example, in South Dakota vs. Yankton Sioux (1998) the court permitted South Dakota to build a landfill on the Yankton Sioux Reservation over the tribe’s objection.

In Idaho vs. Coeur d’Alene Tribe (1997) the court had denied the Coeur d’Alene Tribe the ability to file a claim asserting rights to land under Lake Coeur d’Alene which abuts the Reservation

And in South Dakota vs. Bourland (1993) the court had held that the Cheyenne River Sioux Tribe lost the exclusive right to regulate hunting and fishing on the portion of the reservation that was flooded by dams built by the United States to provide flood control to non-Indian cities downstream.

But after more than 30 years it appears that the canons are finally making a comeback. The late Justice Antonin Scalia voted with the majority in all of the cases above, but when Justice Neil Gorsuch took Scalia’s seat in 2017 — the judicial math began to change.

On May 20, the Supreme Court issued its second 5-4 Indian law opinion of the current term, and in both cases Justice Gorsuch joined the four liberal justices (Ginsburg, Breyer, Sotomayor and Kagan) in a majority ruling favorable to tribal rights.

In Herrera vs. Wyoming, the court held that the Apsáalooke Nation (also known as the Crow Tribe) retained a right it secured in an 1868 treaty to permit its citizens to hunt in the “unoccupied” lands of the United States. In doing so, the majority expressly overturned an 1896 precedent which had held that such a treaty right did not survive Wyoming’s admission to the Union as a state.

The court went further to emphasize the Indian law canons, explicitly instructing that “Indian treaties ‘must be interpreted in light of the parties’ intentions, with any ambiguities resolved in favor of the Indians,’ and the words of a treaty must be construed ‘in the sense in which they would naturally be understood by the Indians.’ ”

The Herrera decision comes almost two months to the day after the court decided Washington State Dept. of Licensing vs. Cougar Den Inc., where the same 5-4 split recognized that “the right, in common with citizens of the United States, to travel upon all public highways,” secured by the Yakima Nation in an 1855 treaty, prevented the state of Washington from imposing its motor vehicle fuel tax on gasoline imported to the Yakima Reservation.

Indian law is clearly turning a corner. In whatever other ways Justice Gorsuch may be like Justice Scalia, his Indian law jurisprudence is notably different. Perhaps it is because, unlike his brethren on the bench, his stint as an appellate judge was on the Tenth Circuit, covering states like Wyoming, Colorado, New Mexico and Oklahoma instead of a position in Washington, D.C., or on the East Coast.

Gorsuch is the first justice since Sandra Day O’Connor (appointed in 1981) to have spent the majority of his or her professional career west of the Mississippi. It is perhaps worth remembering that his confirmation was supported by the National Congress of American Indians and the Native American Rights Fund.

Indian Country is rightfully celebrating this shift in the court’s thinking about Indian law. The U.S. had ratified 370 treaties with Indian tribes before Congress ended treaty making with Indians in 1871. Article VI of the Constitution directs that these treaties are part of “the supreme law of the land.”

By once again upholding the promises made by the U.S., perhaps the modern court is finally embracing Justice Hugo Black’s sage observation that “Great nations, like great men, should keep their word.”

Grant T. Christensen is a law professor at the University of North Dakota.