Where is this cliff in Iowa?
I am from there. There is no cliff like this, except on the western edge, where there would be the flood-plain of the Missouri river stretching out into the distance. They still are not quite like that (http://en.wikipedia.org/wiki/Loess_Hills)
Perhaps it is a big quarry, now abandoned in the saccharin-sweet eco-friendly Federation daze. They never hesitated to axe-grind. (http://en.wikipedia.org/wiki/Force_of_Nature_(Star_Trek:_The_Next_Generation))