25 USC 1300g7 - Tribal membership

(a) In general 
The membership of the tribe shall consist of
(1) the individuals listed on the Tribal Membership Roll approved by the tribes Resolution No. TC584 approved December 18, 1984, and approved by the Texas Indian Commissions Resolution No. TIC85005 adopted on January 16, 1985; and
(2) a descendant of an individual listed on that Roll if the descendant
(i) has 1/8 degree or more of Tigua-Ysleta del Sur Pueblo Indian blood, and
(ii) is enrolled by the tribe.
(b) Removal from tribal roll 
Notwithstanding subsection (a) of this section
(1) the tribe may remove an individual from tribal membership if it determines that the individuals enrollment was improper; and
(2) the Secretary, in consultation with the tribe, may review the Tribal Membership Roll.