At its northernmost point, the Ohio River is at about same latitude as the straight-line part of the Missouri-Iowa border.
At its southernmost point, at Cairo, it is about the same latitude the straight-line part of the Missouri-Arkansas border. It is also about the same latitude as Norfolk, Va., America's northernmost year-round ice-free port on the East Coast.
If I think of any more geographical oddities, I'll post them, too.
