In May 1869, Major John Wesley Powell, geologist, enthnologist, and geographer set out from Green River, Wyoming, with nine men and four boats to explore the forbidding canyons of the Green and Colorado Rivers in Wyoming, Utah, and Arizona, which had blocked all central travel routes to the West Coast. Powell of the Colorado describes this exploration. Originally published in 1951. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.