Okla. Admin. Code § 50:1-9-6
All findings of fact shall be based exclusively on the evidence presented and on matters officially noticed. A final order adverse to a party in an individual proceeding shall be in writing and shall include findings of fact and conclusions of law, separately stated. Findings of fact, if set forth in statutory language, shall be accompanied by a concise and explicit statement of the underlying facts supporting the findings. If, upon request, a party submits proposed findings of facts, the order shall include a ruling upon each proposed finding. Parties shall be notified either personally or by mail of any order. Upon request, a copy of the order shall be delivered or mailed forthwith to each party and to his attorney of record.
Okla. Admin. Code § 50:1-9-6