The only real way to preserve elephants in the wild is to preserve very large areas of land and set them aside as nature preserves.  The good news is that this is exactly what is being done in a number of places.  In many ways, Sri Lanka is a model of what can be done.  In fact, the people there have a long tradition of wildlife preservation.  Two thousand years ago, the princes and kings of Sri Lanka set aside hundreds of square kilometers as hunting preserves.  And ever since that time, under one form of government or another, the people of Sri Lanka have kept these areas from human development.  So, in effect, these area have served as a nature preserves for two millennia!  

National park land in modern day Sri Lanka

In fact, present day Sri Lanka has an extensive system of national parks—many of them big enough to give us a genuine sense of optimism about the preservation of wild populations of elephants there.  The lesson is that wildlife conservation can be successful if enough people express the will and commitment to do it.  Wild populations of Asian Elephants can, and will, be preserved if we humans have the resolve to to preserve large tracts of wild spaces like those in Sri Lanka.