1863, United States of America. 12-year-old Martha Jane and her family are headed West in large covered wagon train in search of a better life. After Martha Jane’s father is hurt in a serious accident, she takes charge of her siblings and learns to drive the family wagon. She has never felt so free. Utterly practical and bold, Martha Jane dresses as a boy and becomes increasingly troublesome for the community due to her outspoken braveness. When the leader of the convoy wrongly accuses her of theft, she runs away to find proof of her innocence... In the Wild, she discovers herself and a world which shapes her and confirms her unique personality... revealing the mythical and slightly mysterious Calamity Jane.