It isn't necessarily to make a prehistoric park. A surprising additional reason is to possibly combat global warming. And the ironic thing is that global warming (which is real and not a liberal conspiracy as US conservatives claim) is melting the frozen Siberian tundra to an unprecedented degree, exposing more mammoth remains. Providing DNA that may be useable for cloning. Read more...

http://www.nbcnews.com/news/world/scientists-want-bring-back-woolly-mammoths-why-n575581