Okla. Stat. tit. 43A, § 43A-6-103
Residents of state in institutions of other states -
Admission to Oklahoma institution.
Any resident of this state who has been admitted to an
institution for mentally ill in another state, the District of
Columbia, or a territory, in accordance with the laws of that place,
may be admitted to an institution in Oklahoma within the Department
of Mental Health and Substance Abuse Services without further
proceedings in this state.