Nearly half of the state of Oklahoma, including the city of Tulsa, is expected to be considered part of the Indigenous People's Reserve, the Guardian reports.
This can have a number of consequences. For example, the area may to some extent have its own legal system - and that some who have been convicted of crimes at the state level may have the opportunity to appeal the judgments.
The case that was tried by the Supreme Court is about a tribal member who was convicted of child rape in 1997. The man does not deny the crime but believes that the state court was not entitled to convict him because the crime was committed within the boundaries of the reserve.
"Unwanted to get support"According to federal law, suspected crimes committed in a reserve of indigenous people must be tried in federal court, reports The Guardian.
What the Supreme Court would therefore decide was whether or not the crime was committed on a reservation. With five to four votes, the court ruled that this was the case.
The convicted man could now potentially have his case tried in federal court, but is not expected to be released from prison, according to The Guardian.
In a joint statement, representatives of the state of Oklahoma and the indigenous people said they should now work together to straighten out all legal question marks after the decision.
"We in the indigenous population of the United States are used to the fact that people with power do not uphold the law or support us, and that is not what happened today," journalist Rebecca Nagle, who belongs to the Cherokee people, told US NPR in connection with the court ruling.