(1) Authority is granted to and acknowledged in the United States to exercise exclusive legislation as provided by the constitution of the United States over the military reservation of Fort Missoula as established by law to the same extent and with the same effect as if the reservation had been purchased by the United States by consent of the legislative assembly of the state of Montana so long as it remains a military reservation.
(2) All legal process of the state, both civil and criminal, may be served upon persons and property found within the reservation in all cases where the United States does not have exclusive jurisdiction.