 So in June 1946, Aleson and White hiked down Parashant Wash, arriving at the Colorado River at mile 198.After recovering from their epic hike, where they nearly perished from thirst, they built a raft fashioned after James White's, who had allegedly been the first to float the Grand Canyon in 1867.But they were unable to launch it into the raging torrent, running the same volume as the previous year.