White Mountain Apache in Northeast Arizona for elk. Not for the budget minded hunter, but that is the area the current B&C typical record holder came from. I spend a week there every year and have seen some monsters there. Talked to a retired attorney who paid $25,000 plus fees and tips in 2009.
Personally I would stay away from any reservation in SD, WY, MT, and ND. I don't want to go into details on an open forum, pm me if you would like more info.
I asked this question of a Wildlife Biologist in Montana & he does aerial surveys in Montana & on Indian Reservations there are very few Deer. He said the State even offered to help the tribe to help manage there wildlife & they had no interest in doing so.