This page lists Indian reservations in local-America, with a map. The closest is the Qualla in North Carolina. The Mississippi Band of Choctaw owns a land trust in Tennessee, which in T-America is also a real reservation.
In T-America, a chain of lawsuits ending at the Supreme Court in 1949 held that the United States had not just violated treaties with the Cherokee nation, but also its own laws regarding diplomatic relations with sovereign nations and the rulings of the Supreme Court. Specifically, treaties can only be signed between sovereign nations; the act of making a treaty therefore acknowledges the parties as sovereign nations. Among the background cases were Cherokee Nation v. Georgia, Worcester v. Georgia, and Cherokees v. Andrew Jackson. The lawsuits wound through U.S. courts because the Cherokees noisily maintained that if America would not give them justice, they'd take their case to the International Court of Justice, and at that time America wanted very much to keep the United Nations and its branches running smoothly. That made Cherokee Peoples v. United States largely a sacrifice of domestic interests to protect international ones.
In T-America, Cherokees v. Andrew Jackson was a court case similar to Cherokee Nation v. Georgia but focusing on land and treaties in Tennessee. The Supreme Court ruled that the treaties were valid and the Cherokees had the right to their land. The President simply ignored it.
Two key provisions of the United Nations in Terramagne are that member nations must agree to abide by rulings of the International Court of Justice, and that only one party in a dispute must belong to the UN to place the case within ICJ jurisdiction. Ignoring the ICJ can result in serious penalties such as suspension of member rights within the UN until the matter is rectified. This is meant ensure the proper behavior and treatment of UN members, and typically does not presume to mediate disputes between nations that do not belong. However, some things -- such as genocide, crimes against humanity, and war crimes -- are overseen by the International Criminal Court which asserts global authority over issues that everyone civilized agrees upon. Ignoring it has similar effects on UN member rights, and other sanctions for nonmembers. So you can see that both courts have wider reach and more teeth in Terramagne than their local counterparts have here. In theory, all peoples have some legal recourse; in practice, the ones who actually get it are almost always UN members and influence matters a lot. But there's always that chance the court will be sufficiently pissed with you to hand a win to a tribal nation or secessionists or some other small group. It discourages even the biggest countries from getting too flagrant in their mayhem.
In T-America, the outcome of Cherokee Peoples v. United States required the American government to restore land to the Cherokees out of territory controlled by the government rather than private citizens. Thus the Tennessee Band of Cherokees has a reservation spanning parts of Sevier and Cocke counties in Tennessee, ceded from territory formerly belonging to the Great Smoky Mountains National Park and the Pigeon River District of the Cherokee National Forest North. Ross Ridge Reservation is named for John Ross and Major Ridge, who fought valiantly for Cherokee rights. About 9,000 people live on the reservation today. Some bordering towns like Gatlinburg have significant Cherokee populations and businesses. Another 6,000 or so tribal members live in areas near the reservation. Just over 500 members live elsewhere, many of them pursuing education or careers that will allow them to develop the tribe further.
Among the stipulations of the T-Supreme Court in Cherokee Peoples v. United States was that the land ceded must have "significant cultural and/or financial value" because America had so flagrantly stolen sacred lands from all its indigenous nations and forced the few survivors onto the least desirable land remaining. Even here, United Nations investigators have acknowledged violations and said that America should return stolen land. Thus T-America returned substantial parts of the Great Smoky Mountains National Park and the Pigeon River District of the Cherokee National Forest North, necessarily including part of the Tennessee section of the Appalachian Trail. Many (white) people were utterly outraged by this.
The Cherokees, however, maintained that everyone would be welcome to continue using the trail and certain other parts of the reservation, so long as they honored Cherokee laws. As a direct result of this, they control several of the very few towns actually inside the parklands: Rosston (just across the border from Gatlinburg) and Ridgeville in Sevier County, Hartford and Dunenvsv (which means "Homes" in Cherokee) in Cocke County. Of those, Rosston and Hartford are open to visitors, while Ridgeville and Dunenvsv are primarily for tribal members. Rosston, Ridgeville, and Dunenvsv are T-American towns built after the reservation's establishment. Rosston includes a language nest, the Sequoyah Immersion School; and a food manufacturer, Talutsa (which means "basket" in Cherokee). Dunenvsv has the Atsadi Corporation (which means "fish" in Cherokee), a cluster of industries centered around fish. Violations of Cherokee laws, especially in the early days of the reservation, led to a whole lot of construction done via community service. To this day, that stretch has some of the best waystations and outhouses on the Appalachian Trail.
Talutsa is a Cherokee food manufacturer located in Rosston, Tennessee. Their cold cereals include Chestnut Crunch, Corn and Cousins, and Rainbow Corn Girl. They make a hot cereal called Morning Mush.
In Dunenvsv, the Atsadi Corporation runs a factory producing organic fish food, chicken food, and other livestock feed supplies; a fishery raising native fish like black crappie, bluegill, brook trout, channel catfish, flathead catfish, redbreast sunfish, spotted bass, and white crappie; a fish farm producing whole and filleted organic catfish; and a fertilizer plant producing fish emulsion from the fish scraps. They use a traditional method of making fish emulsion by layering it with leaves. They also release brook trout fingerlings to restore dwindling populations.
People argue about whether organic fish farming is even possible, and the government is slovenly about regulations. But it is, if you care about doing it right. That's basically a description of the Atsadi setup.
Fish emulsion is made commercially as a by-product of fish oil. You can make your own the old-fashioned way. I usually just bury fish scraps in my garden, which is a Cherokee tradition.
Tennessee has quite a few fish hatcheries raising various species of fish.
Feel free to prompt for this setting if you wish. I've started watching for T-American tribal interests that combine their historic customs with modern applications, like the fish emulsion factory mentioned above.