Mont. Code Ann. § 2-1-205

2-1-205 . Glacier national park. Exclusive jurisdiction shall be and the same is hereby ceded to the United States over and within all the territory which is now or may hereafter be included in that tract of land in the state of Montana set aside by the act of congress, approved May 11, 1910, for the purposes of a national park, and known and designated as "The Glacier national park", saving, however, to the said state the right to serve civil or criminal process within the limits of the aforesaid park in any suits or prosecution for or on account of rights acquired, obligations incurred, or crimes committed in said state but outside of said park; and saving, further, to the state the right to tax persons and corporations, their franchises and property on the lands included in said park; provided, however, that jurisdiction shall not vest until the United States, through the proper officers, notifies the governor of this state that it assumes police or military jurisdiction over said park.