Could there be a plausible way to have a freshwater river that sources water from a saltwater ocean? By plausible I mean by means of everyday, scientifically-sound, boring-ass reasons, so no magic.
I am not a scientist, and do not know anything about rivers. Please help.
I think one of the defining features of rivers is that they flow down to sea level right? So I don't think so. But maybe if you have a salty inland sea at high altitude and the river flows down from there?