In the late 1800's, teenager Mayme Watson boards a train bound for Eagle Rock, Idaho. Disillusioned by her parents and completely alone, she finds a place to stay and a job to support herself. When Mayme discovers that most of the girls in town are just biding their time until they can marry, her heart calls for a change. She embarks on an adventure to overcome her feelings of failure by disguising herself as a boy and getting hired on as a post rider...