The only humans in the Americas at that time were Indians, uh, sorry, Siberian-Americans, who we all know lived in peace and harmony with their surroundings and were perfect stewards of the environment. (Of course they did cultivate a little of that awful weed for smoking - tobacco.)
They couldn't possibly have caused thye extinction of any species. It has to be evil European white males who are responsible for this travesty. (Maybe the Vikings got here earlier than anybody thought.)
I demand restitution from the American Indians for killing the Mastadon!
. . . around the high plains of West Texas/Panhandle (e.g., near Canyon is one example), you can still find huge piles of bones where the Indians would repeatedly drive entire herds of buffalo off the cliffs . . .
Such a sensitive group of folks.