Broadly speaking, a treaty, be it with a native tribe or a foreign country, is US law once it is ratified. So they impact our future as a country as long as they are still in effect.
The terms of treaties we have signed with various native tribes were often ignored over the decades, but many if not most of them guarantee those tribes a percentage of the natural resources, or sovereign control over reservations.
So in my home state of Washington, the Yakama tribe, for example, is entitled to a large percentage of the salmon which return each year, and to this day, there are fishing days each year for natives only, with no individual limit.
In a recent court ruling and a bill passed this month by Congress, the US government approved giving the tribes $4.6 billion in payments that were due them by treaty and had never been paid. Just to give you a couple of examples.