Arkansas lawmakers oppose tribe’s request to put land into federal trust

Four members of Arkansas’ congressional delegation are asking the U.S. Department of the Interior to reject a request by the Quapaw Tribe of Oklahoma to place a 160-acre tract of land in Central Arkansas into federal trust. U.S. Sens. John Boozman and Tom Cotton, both R-Ark., and U.S. Reps. Bruce Westerman, R-Hot Springs, and French Hill, R-Little Rock, said in June 29 letters to Interior Secretary Sally Jewell and Assistant Secretary of Indian Affairs Kevin Washburn that they support earlier letters from Gov. Asa Hutchinson and Pulaski County Judge Barry Hyde opposing the tribe’s request. Placing the land into federal trust would allow the tribe to exercise jurisdiction over it. Some officials have questioned whether the tribe might build a casino on the land, although the tribe has said it has no plans for a casino and only wants to preserve burial mounds and artifacts dating back to the days before the tribe was removed to reservations in Kansas and what is now Oklahoma. The lawmakers wrote in their letters that Hutchinson and Hyde “feel such a designation would be a significant disruption to the safety of the surrounding community,” and they “are in the best position to determine the impacts, both positive and negative, granting such an application would have.” They also said federal law dictates that the greater the distance between proposed lands and a tribe’s reservation, the greater the scrutiny that an application must receive...more

I guess I'm a little confused by this process.  Article I, Section 8 of the U.S. Constitution states:

To exercise exclusive legislation in all cases whatsoever, over such District (not exceeding ten miles square) as may, by cession of particular states, and the acceptance of Congress, become the seat of the government of the United States, and to exercise like authority over all places purchased by the consent of the legislature of the state in which the same shall be, for the erection of forts, magazines, arsenals, dockyards, and other needful buildings 

Has the Arkansas legislature approved this?  How can the feds exercise exclusive jurisdiction without their approval?