Actually, Omaha is supposed to mean "above all others" on a river. That is further proof that South Dakota and North Dakota don't exist. They are just a figment of someones imagination.
However, your translation of Council Bluffs is right-on.
Actually, Omaha is supposed to mean "above all others" on a river. Yeah, that's the "sanitized" definition. But there are natives who insist that the true translation is considerably less flattering.
On the other hand, there is no ambiguity regarding Council Bluffs. All they need is banjo lessons ...