Okla. Stat. tit. 57, § 57-61: Sheriff to keep copy of order of confinement

When a prisoner is confined by virtue of any process directed to

the sheriff, and which shall require to be returned to the court

whence it issued, such sheriff shall keep a copy of the same,

together with the returns made thereon, which copy, duly certified

by such sheriff, shall be prima facie evidence of his right to

retain such prisoner in custody.