I am of course familiar with the story that the mammoths were destroyed by ice-age hunters, who hunted them to extinction. It turns out that the warmup after the ice ages helped the spread of forests, which reduced the grazing for mammoths.
When you think about the old story, there are questions. Native Americans never hunted out the buffaloes or any other game animal they hunted. Why should their ancestors have done that?
As a forester, I always think of any increase in forest area as something to be desired. But it doesn't seem to be if you are a woolly mammoth!