In the event the federal government dissolved, what would happen to the Native American reservations

[I spent the winter writing songs about getting better]

Tribal sovereignty predates the United States and would persist after it.

Tribal sovereignty is a myth that is theoretically enforced by the federal government holding "Indian land" in trust and thus stopping state sovereignty from going into effect. If the federal government ceased to exist, "Indian land" would be held by the states under the same provisions as any other state land, and the reservations would disappear.

Wrong, see above. States lack sovereignty over tribes, which are not organized under or subject to state law. This is why tribes cannot, for example, be subject to suit in state courts, regardless of whether they have trust land. There are also certain tribes that exercise all the usual powers of tribes over their land despite holding it in fee simple themselves, as opposed to the federal government holding it in trust.

Wait, so does this mean that any Reservation could legalize and start selling marijuana in any state?

[I spent the winter writing songs about getting better]

Wrong, see above. States lack sovereignty over tribes, which are not organized under or subject to state law. This is why tribes cannot, for example, be subject to suit in state courts, regardless of whether they have trust land. There are also certain tribes that exercise all the usual powers of tribes over their land despite holding it in fee simple themselves, as opposed to the federal government holding it in trust.

Wait, so does this mean that any Reservation could legalize and start selling marijuana in any state?

No, because marijuana is still listed under the federal Controlled Substances Act — tribes are still subject to federal law. If marijuana became legal federally, then yes, any reservation* could legalize marijuana. "Selling" gets a little more complicated, because a state could still prosecute you if, say, you bought marijuana on the Pine Ridge reservation and then drove back to your hotel room off-reservation. But just having a store on the reservation would probably be okay; I'd expect it would be more focused on on-site consumption/experiences than just a dispensary because of the issue with sales to non-Indians who live off the reservation.

Then how do Reservations sell marijuana in states where it's legal if state law doesn't matter? The only place in Minnesota currently where you can buy marijuana (aside from the hemp-derived THC edibles and drinks) is the Red Lake Reservation.

[I spent the winter writing songs about getting better]

So if state law doesn't apply on Reservations that actually opens up all sorts of questions, like take driver's licenses, those are issued by the state, so how would people on a Reservation get one? My parents definitely had North Dakota ones while on Standing Rock. Does a suspended license mean you can still drive in one? And what determines penalties for crimes, if you kill someone on a Reservation are you actually charged under some tribal statute for murder instead of the state one?

[I spent the winter writing songs about getting better]

So if state law doesn't apply on Reservations that actually opens up all sorts of questions, like take driver's licenses, those are issued by the state, so how would people on a Reservation get one? My parents definitely had North Dakota ones while on Standing Rock. Does a suspended license mean you can still drive in one? And what determines penalties for crimes, if you kill someone on a Reservation are you actually charged under some tribal statute for murder instead of the state one?

Okay, so here's how law applies on reservations:

In criminal matters, it depends on the Indian status of the parties involved. Crimes committed by Indians are never under state jurisdiction. Instead, "major" crimes (murder manslaughter kidnapping maiming incest burglary robbery arson etc) fall under federal and tribal jurisdiction concurrently. In practice, these are almost always punished by the federal government, given their resources and given certain limits on sentencing available in tribal court under the Tribal Law and Order Act. "Non-major crimes" (anything not on the list) are under federal and tribal concurrent jurisdiction if the victim is non-Indian and exclusively within tribal jurisdiction if the victim is also Indian (or pursuant to certain treaty provisions). These you much more often see the tribes prosecute, given limited federal resources to prosecute and the fact that sentences tend to be shorter. (It is unclear whether the federal government can prosecute Indians who commit victimless crimes like, say, marijuana possession; one of the many reasons they are reluctant to try.)

Crimes committed by non-Indians against non-Indians on the reservation, assuming they are not independent federal crimes, are punished under the law of the applicable state by state prosecutors. Crimes committed by non-Indians against Indians, on the other hand, typically fall under federal jurisdiction; certain offenses (domestic/dating violence) can also be prosecuted by tribes. The Supreme Court has also erroneously concluded that states also have jurisdiction over these offenses; this was recent, so not clear how much that will change things. And non-Indians who commit victimless crimes on the reservation can definitely be punished by the state; whether the federal government can exercise jurisdiction here is unclear, though that has not stopped them in the past.

For civil laws, federal and tribal laws apply to Indians. States are presumed to have no authority to regulate Indians on Indian land. For non-Indians coming onto the reservation, whether states can apply their law to these individuals is subject to a complex balancing test that comes from a case called Bracker that looks at factors like off-reservation effects of the on-reservation activity, the compatibility of the state regulatory regime with tribal and federal law, whether value is being produced in or outside of Indian country, the extent of the state activity, and the backdrop of tribal sovereignty.

Whether tribes can apply their civil laws to non-Indians coming onto the reservation, meanwhile, is even more complicated and varies widely by subject matter and by which federal circuit the reservation is located on. There's a multi-stage test you work through, with flowcharts. Usually you think (I think) that tribal law will apply if you are on tribal land within the reservation boundaries, but not if you are on non-Indian-owned fee land within the reservation or just passing through on a right-of-way. You also then look at the relationship between the party being regulated and the tribe (if they have a contract, for example) and whether questions of tribal government or welfare are involved.

Interesting. My parents are somewhat familiar with some of this but because they weren't running afoul of the law much obviously, (the closest thing is probably buying black market alcohol from importers from Bismarck/Mandan when Standing Rock was briefly dry, and buying their own alcohol in Bismarck and bringing it back, but that's not illegal, only the sellers were breaking the law.) but not that level.

So does this mean that marijuana is de facto legal for anyone with recognized Indian status in Tulsa, Oklahoma? (Which as we learned from Update applies to quite a few people in Oklahoma who definitely would not be considered Indian in any other context.)