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 area in the state of Michigan set aside and dedicated for park purposes by the United States as Isle Royale National Park including any submerged lands within four and one-half miles of the shore line of Isle Royale and immediately surrounding islands, the title to which is hereby conveyed to the United States; saving, however, to the state of Michigan all oil and mineral rights in and to said submerged lands and the right to serve civil or criminal process within the limits of the aforesaid park in suits or prosecutions for or on account of rights acquired, obligations incurred or crimes committed in said state outside of said park; and saving further to the said state the right to tax persons and corporations, their franchises and property on the lands included in said park; and saving also to the persons residing in said park now or hereafter the right to vote at all elections held within the county or counties in which said park is situate, and saving further that fishing in said waters shall be subject to and conducted according to state laws applicable thereto: Provided, however, That jurisdiction shall not vest until the United States through the proper officer notifies the state of Michigan that they assume police jurisdiction over said park.