off the reservation
1. Outside the bounds of control, propriety, or acceptance of a given group. The phrase refers to the forced relocation of Native Americans to Indian reservations in the United States. Because of this origin, the phrase can be considered offensive or inappropriate. The youths in this area seems content to remain largely off the reservation, as if they are beholden to no form of authority.
2. Different or contrary to the accepted norm. The vice president seems to be off the reservation regarding his views on legalizing marijuana.