So if i understood that right, the outer edges of the forest, where the feeder rivers are, would be a slightly higher elevation then the large winding river.

As for doing the thing in gimp or what ever, i don't have to worry about that as I'm paying a guy to do the map. I just wanted to make sure the river in itself was possible there. That it didn't break any river rules. Which it sounds like its fine. I will just have him draw try and draw it like you described, if its even needed. As a high up aerial view I'm not sure if it would need to be shown that way anyway.

Now my second question, one of my other rivers flows south and when it hits a desert (large sand dune type desert) it goes under the sand and pops back up in the forest. Would they logically do that? I figure it could hit an underground cave system.