The degree of preservation in Siberia is astounding, and there is a good chance that mammoths can be essentially resurrected. The bigger question is - What do you do with the mammoth once (s)he is here?

The critter needs an appropriate environment, and the demise of that environment is the reason they went belly up in the first place....A mammoth might be very happy, browsing in an Illinois corn field, although its owner might not be too thrilled.