I remember a scene where two teenagers are falling down rapids in a river and pull themselves out only to realise there are leeches, so they then start taking off their clothes before getting embarrassed and hiding behind foliage from each other.
I just revisited A Far Off Place (1993) because I’d recently remembered seeing that as a child, and thinking that the scene would be in it but it wasn’t. As such the movie may also be about the teenagers escaping from someone who’s trying to kill them or their families. I seem to think the movie might also have had Native American characters.