"Holy Night!": Karl May (1st ed. out of print)

Old Shatterhand and his blood brother Winnetou, the Apache chief, are on the trail of robbers who have stolen an entire trunk full of gold nuggets. After rescuing Carpio, Shatterhand's old school friend in the wintry Rocky Mountains, they find shelter in a Pa-Ware, the extraordinary geological feature that becomes the stage for a life-changing experience with a grizzly bear.