18 U.S.C. § 1152 : US Code - Section 1152: Laws governing

Search 18 U.S.C. § 1152 : US Code - Section 1152: Laws governing

Except as otherwise expressly provided by law, the general laws
of the United States as to the punishment of offenses committed in
any place within the sole and exclusive jurisdiction of the United
States, except the District of Columbia, shall extend to the Indian
country.
This section shall not extend to offenses committed by one Indian
against the person or property of another Indian, nor to any Indian
committing any offense in the Indian country who has been punished
by the local law of the tribe, or to any case where, by treaty
stipulations, the exclusive jurisdiction over such offenses is or
may be secured to the Indian tribes respectively.