https://www.youtube.com/watch?v=cQRrlkkFhbM&feature=emb_logo
It appears the Lakota were given plenty of tax free land to maintain their nation, independence and freedom.
https://en.wikipedia.org/wiki/Lakota_people
Today, the Lakota are found mostly in the five reservations of western South Dakota:
Rosebud Indian Reservation, home of the Upper Sičhánǧu or Brulé.
Pine Ridge Indian Reservation, home of the Oglála.
Lower Brule Indian Reservation, home of the Lower Sičhaŋǧu.
Cheyenne River Indian Reservation, home of several other of the seven Lakota bands, including the Mnikȟówožu, Itázipčho, Sihásapa, and Oóhenumpa.
Standing Rock Indian Reservation, home of the Húŋkpapȟa and to people from many other bands.
Lakota also live on the Fort Peck Indian Reservation in northeastern Montana, the Fort Berthold Indian Reservation of northwestern North Dakota, and several small reserves in Saskatchewan and Manitoba. Their ancestors fled to "Grandmother's [i.e. Queen Victoria's] Land" (Canada) during the Minnesota or Black Hills War.
If they are unhappy with the deal, I would not mind taking possession of the Cheyenne River reservation. Looks very scenic.