We have an unknown distance yet to run; an unknown river yet to explore. What falls there are, we know not; what rocks beset the channel, we know not; what walls rise over the river, we know not. Maj. John Wesley Powell (1869) More than a century after Major Powell completed the first descent of the Colorado River through the Grand Canyon, a great many of the world's rivers had still never been run. The guides of Sobek set out to change that, and did more than 100 first descents of rivers around the world, many of which became classic commercial trips, including the Omo (Ethiopia), Tatshenshini/Alsek (Canada/Alaska), Watut (Papua New Guinea), Bio Bio (Chile), Coruh (Turkey), and Zambezi (Zambia/Zimbabwe). Meet the guides and hear their stories from the cutting edge of adventure.