Okla. Stat. tit. 18, § 18-441-1302
Proper plaintiff
PROPER PLAINTIFF.
(a) A derivative action to enforce a right of a limited
cooperative association may be maintained only by a person that:
(1) Is a member or a dissociated member at the time the action
is commenced and:
(A) was a member when the conduct giving rise to the
action occurred; or
(B) whose status as a member devolved upon the person by
operation of law or the organic rules from a person
that was a member at the time of the conduct; and
(2) Adequately represents the interests of the association.
(b) If the sole plaintiff in a derivative action dies while the
action is pending, the court may permit another member who meets the
requirements of subsection (a) of this section to be substituted as
plaintiff.