Okla. Admin. Code § 460:2-41-2
A petitioner(s) for the designation of land as unsuitable for surface coal mining shall be considered statutory parties. Any other person claiming a right to participate as a party may seek to intervene in a proceeding by filing allegations of facts, supporting evidence, a short statement identifying the petition to which the allegations pertain, and the intervenor's name, address, and telephone number. Persons with an ownership interest of record in the property and other persons known to the Department to have an interest in the property and other persons known to the Department to have an interest in the property shall be parties. Any interested local, state, or federal agency, including OSM and EPA, shall have the right to intervene as parties.
Okla. Admin. Code § 460:2-41-2