200 years ago and a billion passenger pigeons used to fill eastern skies headed toward vast roosts, the Pigeon Points, and Roosts on today's maps. 10,000 years ago and herds of mammoths, giant beavers and ground sloths, huge Volkswagen-bug-sized relatives of the armadillo, huge tortoises and the biggest lion on Earth traversed our landscape, and more huge critters besides. Men hunted them all to extinction. Let's save what's left. And maybe even reintroduce the pachyderm to the warmer parts of the continent, and rhinos which evolved here (!) too. We can undo some mistakes, maybe.