Yeah. Look at the region borders

. But yeah, there are some regions that are weird: I think there's one in TN that has a partial river boundary just from looking at the map, but holding shift says it's a river boundary. There's a region in PA near Gettysburg that has a very narrow "Polish corridor" between two regions; this little stretch of land between two rivers. By the way, the connection between the interrupting region and the region above it is a river. AACW really should have smaller regions; perhaps they should also be more uniform in size. I know that makes it like a trite hexagonal tesselation, though.