Mari Hulbutta, my friend and suitemate from college—we were both members of the Native American student group—couldn’t sleep Wednesday, the night before the Supreme Court issued its decision in the landmark Native-treaty-rights case, McGirt v. Oklahoma. Hulbutta is a citizen of the Chickasaw Nation and a descendant of the Muscogee Creek and Seminole Nations, all in present-day Oklahoma. The McGirt case centered on whether Jimcy McGirt, a Seminole man found guilty of sex crimes, could be tried by the state of Oklahoma. McGirt contended that because his offenses occurred on lands guaranteed to the Muscogee Creek Nation in an 1866 treaty—one never legally extinguished by Congress—only federal authorities could prosecute his case. The state of Oklahoma has no jurisdiction on Indian land. Tribes can prosecute most crimes involving Native Americans in their own courts. Major crimes, such as murder, manslaughter, and kidnapping, rise to the federal government. The Muscogee Creek became involved with McGirt’s litigation because it had broad implications for their treaty rights, sovereignty, and jurisdiction. Tangentially, the case also involved the Cherokee, Choctaw, Seminole, and Chickasaw tribes, all relocated on the Trail of Tears from what is now the American South to eastern Oklahoma. “I wasn’t sure which way it was going to go,” Hulbutta told me by phone Thursday. “I was thinking about the decision and wondering what it was going to mean for my family and Muscogee relatives.”

Hulbutta recently graduated from Columbia Law School and is studying for the California bar. For many Native people, becoming a lawyer is kind of a thing. Congress has ratified more than 370 treaties with Native nations—treaties that the United States Constitution describes as the “supreme Law of the Land.” But it has broken just about every single one. That’s a lot of injustice, which makes for a lot of work for a lot of Native attorneys. “Honestly, growing up in Oklahoma as a Native person was one of the biggest drives to go to law school,” she explained. “Up until today, it was unclear how I could even describe my tribal lands to people.”

In the long Indigenous struggle for justice, McGirt v. Oklahoma might be one of the most important Supreme Court cases of all time. The decision, 5–4 in favor of McGirt and the tribe, acknowledges that Congress has never extinguished the reservation lands set aside for the Muscogee Creek Nation in 1866. Or, put more plainly, 19 million acres composing 47 percent of the state of Oklahoma—an area that’s home to 1.8 million people—is still Native land. Writing the majority opinion, Justice Neil Gorsuch grasped the gravity of the ruling. “On the far end of the Trail of Tears was a promise,” he wrote in an opening line sure to reverberate through Indian law and history. “Today we are asked whether the land these treaties promised remains an Indian reservation for purposes of federal criminal law. Because Congress has not said otherwise, we hold the government to its word.” That the government must keep its promises and follow the law should hardly be controversial. Yet for the treaty rights of Indigenous nations to finally be recognized—by an appointee of Donald Trump, no less—is bracing, perhaps even startling, to me and other Native people, given how long the United States has denied tribes their dignity, and how this administration has elsewhere attempted to turn back the clock.

At least with respect to Indian law, several tribal attorneys told me, this Supreme Court might just be the Gorsuch Court. Tribal attorneys “will be quoting that decision for the rest of our lives,” Riyaz Kanji, the lawyer who argued the McGirt case on the tribe’s behalf, told me. “The Court is not going to be in the business of taking away tribal rights without congressional intent anymore.” He added, “I’ve cried a lot today.”

What is most intriguing is the way the Court arrived at this decision. Gorsuch, a westerner with experience in Indian law, who is no liberal, applied a conservative textualist approach to the reading of treaty law and statutes. The result: A legal theory that has been marshaled to combat abortion rights and gay marriage delivered the most significant and favorable Supreme Court decision for tribes in the 21st century. Amid a national reckoning for racial justice brought on by the Black Lives Matter movement, who could have predicted that?