They helped decimate the buffalo herds, didn't they?
Exactly. Contrary to pop belief again, the buffalo would have been gone eventually due to the Natives.
Now, we didn't help matters and sped up the bison extinction, but still.
Out in the southwest, there are pueblos, and the Anacazi or whatever they were called around 1000 years ago actually had to leave their initial homeland because they were burning down all the forest etc.