Can anyone suggest material on how to run a wilderness-based campaign? I know I've run across it before, info on how to structure open areas into adventuring zones and such, but I can't seem to find it now. Even suggestions would be helpful - I'm thinking a cave or two could amount to a dungeon adventure, but that doesn't really give an outdoorsy "feel" to it.
In case it matters, the area they'll be adventuring will be a very large island that fades from coastal plains to dense rainforest at the center.
Thanks in advance!