Thanks for the good tips - particularly the point about the northern river. It looks obvious in hindsight, lol. This is one of those times I wish I could afford decent terrain software. In response to the question about tapering the rivers: yes, they're that way on my working map, or rather will be once I figure out which ones I'm keeping. Didn't want to waste my work on the small ones.

At this point the planet hasn't been settled yet (it's for a science-fantasy story) so no civilization to guide me. But I may end up taking out some of the smaller streams as I rework things anyway. I'll post more as I rework things.

Thanks again. Cheers!