When young Tuk is born on the mountain, life is simple for a young bighorn. Run, jump and play with his bandmates, eat and grow strong. But soon it will be up to Tuk to lead the herd to a new mountain he has seen far to the west. It will be a long journey filled with dangers. Wolf, bear, wolverine, puma — and man. The responsibility to lead the herd sits uneasily on Tuk’s shoulders. But Tuk is the one who has seen the blue mountain in the distance, and his bandmates are count