Okla. Admin. Code § 475:10-1-23
The listing of mescaline as a controlled dangerous substance in Schedule I of the Uniform Controlled Dangerous Substances Act does not apply to the non-drug use of the peyote cactus in bona-fide religious ceremonies of the Native American Church, and members of the Native American Church so using the peyote cactus are exempt from registration with the Oklahoma State Bureau of Narcotics and Dangerous Drugs Control. Any person who produces peyote cactus for, or distributes the peyote cactus to, the Native American Church of the State of Oklahoma, however, is required to obtain registration annually as a distributor and to comply with all other requirements of the Uniform Controlled Dangerous Substances Act and OAC 475.
Okla. Admin. Code § 475:10-1-23