More than that, we completely transformed the native ecology of places such that they're nearly unrecognizable from what they once were. Native plants only occupy a tiny, tiny slice of the ecology that they used to, thanks to invasive introductions that came either accidentally or deliberately with livestock and agricultural imports. I know that in California, many of the plants the native people depended on are difficult to find anymore, and are almost never deliberately cultivated. We also took deliberate, calculated steps over decades to eradicate their cultures, and since very little was ever written down, it was largely successful.
In spite of all that, AFAIK there IS at least a Dine restaurant that they're using to try and teach their own people and others about their traditional culinary and food-ecology practices.