Cindy Shogan

The most compelling arguments are the ones we forget about using -- and that is the beauty and the special nature and the wildness of the place, it's not everybody's cup of tea, but the fact of the matter is it is unique. It truly is the last great wilderness. A lot of people like the idea that there's a place like that that's still left, and they want it to be left for future generations.

Exactly when and where they go is impossible to predict. Most herds, however, are drawn to a specific calving area. The 169,000 member Porcupine caribou herd has such a connection with Arctic Refuge.