15 USC 6312 - Professional boxing matches conducted on Indian reservations

(a) Definitions 
For purposes of this section, the following definitions shall apply:
(1) Indian tribe 
The term Indian tribe has the same meaning as in section 450b (e) of title 25.
(2) Reservation 
The term reservation means the geographically defined area over which a tribal organization exercises governmental jurisdiction.
(3) Tribal organization 
The term tribal organization has the same meaning as in section 450b (l) of title 25.
(b) Requirements 

(1) In general 
Notwithstanding any other provision of law, a tribal organization of an Indian tribe may, upon the initiative of the tribal organization
(A) regulate professional boxing matches held within the reservation under the jurisdiction of that tribal organization; and
(B) carry out that regulation or enter into a contract with a boxing commission to carry out that regulation.
(2) Standards and licensing 
If a tribal organization regulates professional boxing matches pursuant to paragraph (1), the tribal organization shall, by tribal ordinance or resolution, establish and provide for the implementation of health and safety standards, licensing requirements, and other requirements relating to the conduct of professional boxing matches that are at least as restrictive as
(A) the otherwise applicable standards and requirements of a State in which the reservation is located; or
(B) the most recently published version of the recommended regulatory guidelines certified and published by the Association of Boxing Commissions.