depending on the person, it can be impossible. some native tribes were wiped out, some native tribes were fully "assimilated" by white cultures. this wikipedia article gives a semi-decent overview, but things like indian schools, the office of indian affairs, the dawas rolls, etc wiped out or replaced a lot of culture that previously existed and is now completely gone with no trace or records. some people with native blood are so far removed from their culture that the cultures are not willing or able to accept them back into the fold. it is a very complicated situation made so by hundreds of years of active genocide against the native population. and there is a huge protection of the culture from white people exploiting it for their own gains, so often anglos who would wish to immerse themselves in or learn about native culture are turned away. of course there still ARE places, etc where they can learn those things, but it is a very complicated issue because of the history of the people here.