Explore one of the nation's greatest natural wonders and celebrate the 100th birthday of Grand Canyon National Park with this grand voyage. Join John Wesley Powell's expedition to explore one of the 7 Wonders of the Natural World, and one of the last unmapped portions of the continental United States. Powell's detailed descriptions of the rocks, plants, and animals seen in the canyon, the geography of the area, and his team's interactions with native groups of the area and mishaps along the trail allow readers to feel the thrill, the awe, and the humility of standing on the canyon's edge. Powell's account of his groundbreaking expedition on the Colorado and Green rivers joins Gibbs Smith's best-selling Wilderness series, standing beside the works of Henry David Thoreau, John Muir, Mark Twain, and Jack London.