Okla. Stat. tit. 63 § 684.5
Limitations
Any party state requested to render mutual aid or conduct exercises and training for mutual aid shall take such action as is necessary to provide and make available the resources covered by this compact in accordance with the terms hereof; provided that it is understood that the state rendering aid may withhold resources to the extent necessary to provide reasonable protection for such state.
Each party state shall afford to the emergency forces of any party state, while operating within its state limits under the terms and conditions of this compact, the same powers, except that of arrest unless specifically authorized by the receiving state, duties, rights, and privileges as are afforded forces of the state in which they are performing emergency services. Emergency forces will continue under the command and control of their regular leaders, but the organizational units will come under the operational control of the emergency services authorities of the state receiving assistance. These conditions may be activated, as needed, only subsequent to a declaration of a state emergency or disaster by the governor of the party state that is to receive assistance or upon commencement of exercises or training for mutual aid and shall continue as long as the exercises or training for mutual aid are in progress, the state of emergency or disaster remains in effect, or loaned resources remain in the receiving state, whichever is longer.
Okla. Stat. tit. 63, § 684.5