Drawing on rarely examined diaries and journals, Down the Great Unknown is the first book of narrative nonfiction to tell the full, dramatic story of the Powell expedition.On May 24, 1869, a one-armed Civil War veteran, John Wesley Powell, and a ragtag band of nine mountain men embarked on the last great quest in the American West. Their goal was the Grand Canyon, an area of the United States not explored before, as mysterious as Atlantis--and as perilous. The ten men set out for their American West exploration from Green River Station, Wyoming Territory, down the Colorado River in four wooden rowboats. Ninety-nine days later, six half-starved wretches came ashore near Callville, Arizona.Lewis and Clark opened the West in 1803; six decades later, Powell and his scruffy band aimed to resolve the West's last mystery. A brilliant narrative, a thrilling journey, a cast of memorable heroes--all these mark Down the Great Unknown, the true story of the last epic adventure on American soil.This gripping work of historical nonfiction reveals their incredible true story--a definitive account of bravery, survival, and the obsession to conquer the unknown.American West History: Follow the 1869 journey of John Wesley Powell, a one-armed Civil War veteran, as he leads a band of mountain men on the last great quest in the American West, decades after Lewis and Clark.Epic Exploration: Witness the first-ever descent of the Colorado River through the Grand Canyon, a region as mysterious and perilous as Atlantis, based on rarely examined diaries and journals.A Harrowing Survival Story: Experience the treacherous ninety-nine-day expedition where ten men in four wooden boats battled the elements, and only six half-starved wretches made it to the end.Definitive Powell Biography: Delve into the life of John Wesley Powell, an amateur explorer and geology professor whose ambition and leadership drove one of the last great adventures on American soil.