There is no good enough DNA to do a cloning of an original mammoth - and also if we did, it would not have any mates. The best chance is to identify the critical genetic variants that made the mammoth adapted to its niche, insert those in elephant. This mutated / genetically engineered elephant would fill the same function and "walk and talk" like the original mammoth - but with the advantage that one can breed with elephants to make more of them. People may think that this is a bit of a strange effort - to de-extinct mammoths, but in fact it might actually make a huge ecological service since a lot of species originally evolved under the pressure of mammoth and other megafauna herbivory. Re-wilding (like how re-introduction of wolves could stop erosion in an American national park) is actually a pretty cool trend.