1912. One of Zane Grey's Ken Ward series of books for boys. A great adventure read from the great author of Western fiction. The book begins: What a change from the Arizona desert The words broke from the lips of Ken Ward as he leaned from the window of the train which was bearing his brother and himself over the plateau to Tampico in Tamaulipas, the southeastern state of Mexico. He had caught sight of a river leaping out between heavily wooded slopes and plunging down in the most beautiful waterfall he had ever seen.