While still a young boy, Peter is orphaned when his parents' stage coach is held up. Peter's parents are killed, but young Peter escapes. He is knocked into a stream which carries him into a lost valley deep in a canyon. Peter is pulled from the stream and then protected by a white horse. Later, an old man residing in the valley finds and raises Peter. The boy gains super strength because of the depth of the canyon since it has a much greater pull of gravity. He also becomes a master in cowboy skills and bonds with the white horse, which he names Cloud (Cloud is also stronger and faster than normal horses). However, once the two reach adulthood, they leave the valley to fight crime as the White Rider and Super Horse.