I used to live and work on an eastern US rez. It's one of those heartbreaking things where you can see the problems, but there's no easy way to fix them.
Just an example: the problem, for a long time, was poverty. No education, no services, impossibly rural. So what's the solution? Casinos! Cut checks from the profits and enrich the community, raise the standard of living, and lay the foundations for the next generation. But now you have new problems -- one guy drinks his way through his per capita check in six weeks and goes back on assistance. Another works maybe four months out of the year, and lives the other eight off his check, still at the border of poverty.
Some will blow their money in an orgy of unbridled spending. The local Wal-Mart runs three guys a day for two weeks leading up to per caps, assembling bikes and grills and playsets. Four buggies loaded with groceries and beer and electronics and clothes and toys isn't uncommon.
That solid foundation the children were having built? Spent on a new SUV every year. And the children themselves -- they've lost all concept of not having whatever they want as soon as they want it. They're getting a dirtbike in May, and a four wheeler in November. They also, from infancy, get the entire balance of their per cap checks deposited into an account they get the keys to on the day they turn 18. College is paid for by the tribe, but why bother when all your friends live on the rez and do nothing, and you can buy a house and a Hummer on a whim?
So you still get that small minority that climb their way out, run the fuck away, and occasionally come back to enrich the community. But now instead of having a population of indigent people mired in poverty, you have a population of nigger-rich people who are mired in senseless spending and the habits of poverty.