Okla. Stat. tit. 21, § 1267.1

Any person organizing or assisting to organize any group, company, assembly of persons, or association with the intent of advocating or encouraging the overthrow of the United States or state governments, or of acting to overthrow such governments, by force or violence, or who is or becomes a member or affiliate of any such organization knowing its purposes shall, upon conviction thereof, be guilty of a Class D3 felony offense and shall be punished by imprisonment as provided for in subsections B through F of Section 20P of this title.