California, 1852. Sage, a golden, big-hearted mutt, is abandoned by her pack. She is about to give up hope when a silly bird squawks her out of her sadness and leads her to Sheng, a young gold prospector. Sheng renames her Bo-Bo, the Chinese word for treasure, and they soon become inseparable.

When Bo-Bo frees a caged bear, the bear's owner--who is also a cruel tax collector--demands a huge price from Sheng for losing the bear. But where can Bo-Bo and Sheng find that much gold? Their only chance is a fabled cave rumored to be filled with treasure. But the cave is supposedly located across the foothills, on a path loaded with danger. Will Bo-Bo and Sheng find it in time?