Jacob McKay is only 14 years old when his family heads West in 1850. On their way to make a new start in the gold fields of California, their journey is halted by a bear attack that destroys their wagon. Forced to set up camp in the Rockies, the McKays meet a wise medicine man and a skilled mountain man named Abner Murdock who help them get settled. Jacob, inspired by their knowledge of the land, sets out to learn their ways. His new survival skills will be put to good use?especially with a giant bear called Walking Thunder on the prowl.