Pursuant to article 1, section 8, paragraph 17, of the Constitution of the United States, consent to purchase is hereby given, and exclusive jurisdiction ceded, to the United States over and with respect to all lands embraced within the military posts and reservations of Fort Sherman and Boise Barracks, together with such other lands in the state as may be now or hereafter acquired and held by the United States for military purposes, either as additions to the said posts or as new military posts or reservations which may be established for the common defense; and, also, all such lands within the state as may be included in the territory of the Yellowstone National Park, reserving, however, to the state a concurrent jurisdiction for the execution, upon said lands, or in the buildings erected thereon, of all process, civil or criminal, lawfully issued by the courts of the state, and not incompatible with this cession.