My brother's getting ready to run a marathon, and he picked one in the Southwest for his first. He told me that he'd looked up the Columbia marathon, and that all the reviews said it was hellaciously hard. So I looked up the course map, and I have to wonder what kind of sadist would make someone run that?!
The course runs from downtown Columbia to the river bottoms and back up, which is an insane amount of vertical for a late summer run in Missouri humidity.