the most common creature is the caribou and not just a few. but hundreds of thousands. the kind of herd unseen since the plains buffalo were wiped away and when he is here with his family, he can t help but wonder how long it will last. do we need to keep some of the places untouched? we are changing the world everywhere. so fast. but why not leave a few places unspoiled? reporter: for almost 60 years, that was the rationale that protected anwar from this. these are the oil fields of prudo bay that fill the pie line and power countless lives. but since there are billions of barrels elsewhere, nature lovers have long argued there s no need to drill here. and for decades that argument held. until one day a friend of mine in the oil business called, is it true that you have anwar in the i said, i don t know. who cares? what is that? he said, you know, reagan tried.