In 1845, Benjamin Davis Wilson--the future first mayor of Los Angeles and the grandfather of Gen. George S. Patton--led a 20-man posse into the San Bernardino Mountains in search of Native American raiding parties that had been attacking Riverside ranches. But what they found in a particular high-altitude valley were, instead, large and furry. Wilson's men soon roped 11 bears, bringing the creatures into camp, and the valley the Serrano Indians knew...