When I moved [to South Dakota], this place seemed empty to me. Learning what Thoreau calls the Art of Walking changes my view. Nestled in an oxbow of the Big Sioux River, the river is a natural quiet greenbelt where kingfishers and green herons, deer and mink and the occasional cougar live as our very near neighbors. We have no great heights here, perhaps, but the prairie is ocean-deep, hushed by the slow roll of steady wind and water falling over pink quartzite falls. There are mountains here, and slowly I am learning to see them.