I watched this movie in the 90s(in color) so I believe it to be a 80s/early90s movie. The girl traveled along the Mississippi(I think) after seeing a person of authority committing a crime. I remember fireworks? She may have been chased by them across the Mississippi or just left the area cause she couldn’t trust anyone-possibly a boy with her.
Thanks in advance for any ideas.
This may be The River Rat (1984)
http://www.imdb.com/title/tt0088006/