Book excerpt: Where the eastern and western currents of American life merge as smoothly as one river flows into another is a place called Nebraska. There we find the Platte, a river that gave sustenance to the countless migrants who once trudged westward along the Mormon and Oregon trails. We find the Sandhills, a vast region of sandy grassland that represents the largest area of dunes and the grandest and least disturbed region of mixed-grass prairies in all the Western Hemisphere. And, below it all, we find the Ogallala aquifer, the largest potential source of unpolluted water anywhere. ø These ecological treasures are all part of the nature of Nebraska. With characteristic clarity, energy, and charm, Paul A. Johnsgard guides us through Nebraska?s incredible biodiversity, introducing us to each ecosystem and the flora and fauna it sustains and inviting us to contemplate the purpose and secrets of the natural world as we consider our own roles and responsibilities in our connection with it.