Here is the majority opinion in McGirt v. Oklahoma [link].
The issue on appeal was whether the State of Oklahoma has criminal jurisdiction over the Creek Indians for crimes committed by them on Creek land. The Supreme Court said, “NO!”
The majority opinion lays out a shameful tale of Congress’ practice of breaking treaties with Indian nations; but points out that it [the Supreme Court] has previously held that Congress has the RIGHT to break Treaties with Indians!
The majority opinion recounts how to get the Creek Nation to give up their ancestral lands in Georgia and Alabama, the federal government promised them (in the Treaty of 1832) that they would have a permanent land in Oklahoma which would be theirs for as long as the Creek nation existed and over which they would have complete self-government.
But in the Major Crimes Act of 1885, Congress decided that they would exercise criminal jurisdiction over the Creeks for major crimes committed by them on Creek Land. And since the Supreme Court has said that Congress isn’t bound by the treaties it makes, we are all just fine with Congress’ unilateral change of mind on this point. 1
So the bottom line of the opinion is that while the federal government has criminal jurisdiction over the Creeks for “major crimes” committed on Creek land; the Oklahoma State government has no criminal jurisdiction over them. 2
Endnotes:
1 As to Congress’ shameful practice of breaking Treaties with Indian Nations (and the Supreme Court’s approval of that disgraceful practice), consider how God punished the Israelites by sending a 3-year famine because King Saul broke the Treaty Joshua had previously made with the Gibeonites. [See the excellent exposition of this event at gotquestions.org [link]]. So when the leaders of a nation commit public sins and the People go along with it, God punishes the People. See, “The Biblical Foundation of Our Constitution” [link].
2 Why should the federal government limit their wrongdoing to the Indians? Why not do it to all of us? And they did! E.g., when they passed the Federal Reserve Act of 1913, they promised that Federal Reserve Notes (FRNs) would be redeemable in gold. Then, the federal government changed their mind and for some 90 years, Americans haven’t been able to redeem FRN’s with gold. See more about the shenanigans respecting the Federal Reserve in “So you think Trump wants to get rid of the fed?” [link].
