McGirt v. Oklahoma, 591 U.S. ___ (2020), was a landmark United States Supreme Court case which ruled that, as pertaining to the Major Crimes Act, much of the eastern portion of the state of Oklahoma remains as Native American lands of the prior Indian reservations of the Five Civilized Tribes, never disestablished by Congress as part of the Oklahoma Enabling Act of 1906. As such, prosecution of crimes by Native Americans on these lands falls into the jurisdiction of the tribal courts and federal judiciary under the Major Crimes Act, rather than Oklahoma's courts.