According to this Lakota legend, this is how the End of the World will come about.

Somewhere at a place where the prairie and the Maka Sicha, the Badlands, meet, there is a hidden cave. Not for a long, long time has anyone been able to find it. Even now, with so many highways, cars and tourists, no one has discovered this cave.

In it lives a woman so old that her face looks like a shriveled-up walnut. She is dressed in rawhide, the way people used to before the white man came. She has been sitting there for a thousand years or more, working on a blanket strip for her buffalo robe. The End of the World according to Lakota legend »»