They had passed through vast tracts of wonderful fertility and beauty, unknown to white men, and through regions abounding in game that they had no time to hunt. From the summit of the Aztec Pass they had gazed, with dismay, over the boundless expanse of the Black Forest, and then had plunged into its dark depths. They had threaded their way through labyrinths of precipitous cañons, the walls of which rose thousands of feet above their heads, and had known of others still more tremendous.