The best way I can answer this is, "living the past into the future". I will not try to answer what ails my neighboring brothers, but I will from my own tribes perspective and yes I have been up in those areas a few times. I had a couple of Inlaws from Ft. Yates area who use to hit the Pow-Wow circuits too.
Depressed areas (Reservation wise) generally close to border towns have a huge alcohol problem because booze is readily within reach and today that is compounded with drugs. These critical components breed crime and some of that criminality sometimes spills into a tribal government (corruption).
Some tribes have been neutered with federal government hand outs, but that's a catch 20/20. The reason why I say that's a catch 20/20 is because of the Treaties that were signed between the tribal headsmen and the US. The US has to honor those treaties, each treaties are different from Tribe to Tribe. President Johnson compounded the problem further by the same laws that kept the Blacks oppressed and dependent on the US government. Each tribe govern themselves by laws set up under the 25 CFR and 45 CFR, however some tribes use those as a guide, thus enacting their own laws to govern themselves (they took the initiative to grow).
Some tribes have stuck with the old system (25 CFR or PL93-638), the hang around the fort ( BIA of US Dept. of Int.) system. It falls back on having a strong leadership with a vision to go forward instead of constantly looking to the past, past is history but learn from it and move forward. I hope this helps Anon, but there is way much more to it than meets the eye.