Criminal Jurisdiction

• Under this law, the United States provides consent to any Indian tribe within an "Indian Country" for jurisdiction over any criminal offense committed by or against Indians within the reservation. California state courts are allowed to take legal action against criminal offenses by, or against, Indians on reservations until the specific case is officially recognized under this Public Law 83-280.
  
  

Civil Jurisdiction

• Indian tribes also have jurisdiction over civil cases of action between Indians or cases to which Indians are parties. The law only applies to cases arising within the reservation. Tribal ordinances or customs adopted by Indian tribes will be used in civil cases if they don't come in conflict with any existing civil law of the reservation.
  
  

Retrocessions & Amendments

• The United States may or may not accept a 'retrocession' of criminal or civil jurisdiction by an Indian tribe. Also, tribes can make amendments to laws that may improve the effectiveness of their criminal and civil jurisdiction over the reservations.