I live around three or four major reservations and have visited others. Poverty among the people governed by the Bureau of Indian Affairs is far, far worse than the poverty of just about any other group, and in part it stems from the policies of the BIA.
There's a little known fact that if land granted to individuals is not worked, lived on, or otherwise improved by those individuals, being effectively unclaimed the BIA auctions it off, and anyone, not just Indians, can bid. The buyer can't necessarily open-sell that land, but given that it's rural farming or ranching land they can profit through its use, and it can be inherited. Worse, the BIA doesn't assign contiguous chunks to family groups, The father's land may be one area, the mother's another, and the childrens' bits spread out. The land not-worked eventually becomes a patchwork of non-native land among the native land in the reservation.
So, first we take away their use of their original lands so we can have them. Then we slaughter large numbers of them them and confine them to 'reservations', then we start taking away the reservations. Yeah, they're so getting special treatment and benefits...