What ways to Native Americans preserve their culture?

They don't, in fact i've met several while i was living in the state of washington and i never met a single one who spoke or could understand there native language. and 90% of the natives i met were not fully native they were mostly mixed with white or some other race. they are more inclined to mix with other races than most which i don't believe there's anything wrong with that, but it shows how much they don't care to preserve their race,culture etc.