Okla. Stat. tit. 8, § 1a

Every cemetery in this state shall have the power to establish and impose reasonable charges for the burial of persons in the cemetery, unless prohibited by law. Failure to pay such charges shall be a misdemeanor and upon conviction be punishable by a fine of not less than Two Hundred Fifty Dollars ($250.00) nor more than Five Hundred Dollars ($500.00). The provisions of this section shall not authorize a cemetery other than those cemeteries owned, maintained or operated by municipalities in this state to impose additional charges not specifically authorized by written contract upon any person for burial if said cemetery has already sold the cemetery lot where such burial is to occur.